Search results for: risk reduction behavior

Authors: Pamela Chia, Tay Yoong Chuan

Abstract:

Introduction: Severe pulmonary hypertension (PH) patients requiring non-cardiac surgery risk have increased mortality rates ranging. These patients are plagued with cardiorespiratory failure, dysrhythmias and anticoagulation potentially with concurrent sepsis and renal insufficiency, perioperative morbidity. We present a deaf-mute patient with severe idiopathic PH emergently prepared for ruptured ectopic laparotomy. Case Report: A 20 year-old female, 62kg (BMI 25 kg/m2) with severe idiopathic PH (2DE Ejection Fraction was 41%, Pulmonary Artery Systolic Pressure (PASP) 105 mmHg, Right ventricle strain and hypertrophy) and selective mutism was rushed in for emergency laparotomy after presenting to the emergency department for abdominal pain. The patient had an NYHA Class II with room air SpO2 93-95%. While awaiting lung transplant, the patient takes warfarin, Sildanefil, Macitentan and even Selexipag for rising PASP. At presentation, vital signs: BP 95/63, HR 119 SpO2 88% (room air). Despite decreasing haemoglobin 14 to 10g/dL, INR 2.59 was reversed with prothrombin concentrate, and Vitamin K. ECG revealed Right Bundle Branch Block with right ventricular strain and x-ray showed cardiomegaly, dilated Right Ventricle, Pulmonary Arteries, basal atelectasis. Arterial blood gas showed compensated metabolic acidosis pH 7.4 pCO2 32 pO2 53 HCO3 20 BE -4 SaO2 88%. The cardiothoracic surgeon concluded no role for Extracorporeal Membrane Oxygenation (ECMO). We inserted invasive arterial and central venous lines with blood transfusion via an 18G cannula before the patient underwent a midline laparotomy, haemostasis of ruptured ovarian cyst with 2.4L of clots under general anesthesia and FloTrac cardiac output monitoring. Rapid sequence induction was done with Midazolam/Propofol, remifentanil infusion, and rocuronium. The patient was maintained on Desflurane. Blood products and colloids were transfused for further 1.5L blood loss. Postoperatively, the patient was transferred to the intensive care unit and was extubated uneventfully 7hours later. The patient went home a week later. Discussion: Emergency hemostasis laparotomy in anticoagulated WHO Class I PH patient awaiting lung transplant with no ECMO backup poses tremendous stress on the deaf-mute patient and the anesthesiologist. Balancing hemodynamics avoiding hypotension while awaiting hemostasis in the presence of pulmonary arterial dilators and anticoagulation requires close titration of volatiles, which decreases RV contractility. We review the contraindicated anesthetic agents (ketamine, N2O), choice of vasopressors in hypotension to maintain Aortic-right ventricular pressure gradients and nitric oxide use perioperatively. Conclusion: Interdisciplinary communication with a deaf-mute moribund patient and anesthesia considerations pose many rare challenges worth sharing.

Keywords: pulmonary hypertension, case report, warfarin reversal, emergency surgery

Procedia PDF Downloads 222

Authors: Bashar Mahmoud, Lee Mortimer, Michael Fairweather

Abstract:

New methods have recently been introduced to improve the thermal property values of molten nitrate salts (a binary mixture of NaNO3:KNO3in 60:40 wt. %), by doping them with minute concentration of nanoparticles in the range of 0.5 to 1.5 wt. % to form the so-called: Nano-heat-transfer-fluid, apt for thermal energy transfer and storage applications. The present study aims to assess the stability of these nanofluids using the advanced computational modelling technique, Lagrangian particle tracking. A multi-phase solid-liquid model is used, where the motion of embedded nanoparticles in the suspended fluid is treated by an Euler-Lagrange hybrid scheme with fixed time stepping. This technique enables measurements of various multi-scale forces whose characteristic (length and timescales) are quite different. Two systems are considered, both consisting of 50 nm Al2O3 ceramic nanoparticles suspended in fluids of different density ratios. This includes both water (5 to 95 °C) and molten nitrate salt (220 to 500 °C) at various volume fractions ranging between 1% to 5%. Dynamic properties of both phases are coupled to the ambient temperature of the fluid suspension. The three-dimensional computational region consists of a 1μm cube and particles are homogeneously distributed across the domain. Periodic boundary conditions are enforced. The particle equations of motion are integrated using the fourth order Runge-Kutta algorithm with a very small time-step, Δts, set at 10-11 s. The implemented technique demonstrates the key dynamics of aggregated nanoparticles and this involves: Brownian motion, soft-sphere particle-particle collisions, and Derjaguin, Landau, Vervey, and Overbeek (DLVO) forces. These mechanisms are responsible for the predictive model of aggregation of nano-suspensions. An energy transport-based method of predicting the thermal conductivity of the nanofluids is also used to determine thermal properties of the suspension. The simulation results confirms the effectiveness of the technique. The values are in excellent agreement with the theoretical and experimental data obtained from similar studies. The predictions indicates the role of Brownian motion and DLVO force (represented by both the repulsive electric double layer and an attractive Van der Waals) and its influence in the level of nanoparticles agglomeration. As to the nano-aggregates formed that was found to play a key role in governing the thermal behavior of nanofluids at various particle concentration. The presentation will include a quantitative assessment of these forces and mechanisms, which would lead to conclusions about nanofluids, heat transfer performance and thermal characteristics and its potential application in solar thermal energy plants.

Keywords: thermal energy storage, molten salt, nano-fluids, multi-scale computational modelling

Procedia PDF Downloads 191

Authors: Charles Shang, Salina Ramirez, Stephen Shang, Maria Estrada, Timothy R. Williams

Abstract:

Purpose: Over the past decade, proton therapy utilizing pencil beam scanning has emerged as a preferred treatment modality in radiation oncology, particularly for prostate cancer. This retrospective study aims to assess the clinical and radiobiological efficacy of proton scanning beam therapy in the treatment of localized salvage prostate cancer, following initial radiation therapy with a different modality. Despite the previously delivered high radiation doses, this investigation explores the potential of proton reirradiation in controlling recurrent prostate cancer and detrimental quality of life side effects. Methods and Materials: A retrospective analysis was conducted on 45 cases of locally recurrent prostate cancer that underwent salvage proton reirradiation. Patients were followed for 24.6 ± 13.1 months post-treatment. These patients had experienced an average remission of 8.5 ± 7.9 years after definitive radiotherapy for localized prostate cancer (n=41) or post-prostatectomy (n=4), followed by rising PSA levels. Recurrent disease was confirmed by FDG-PET (n=31), PSMA-PET (n=10), or positive local biopsy (n=4). Gross tumor volume (GTV) was delineated based on PET and MR imaging, with the planning target volume (PTV) expanding to an average of 10.9 cm³. Patients received proton reirradiation using two oblique coplanar beams, delivering total doses ranging from 30.06 to 60.00 GyE in 17–30 fractions. All treatments were administered using the ProBeam Compact system with CT image guidance. The International Prostate Symptom Scores (IPSS) and prostate-specific antigen (PSA) levels were evaluated to assess treatment-related toxicity and tumor control. Results and Discussions: In this cohort (mean age: 76.7 ± 7.3 years), 60% (27/45) of patients showed sustained reductions in PSA levels post-treatment, while 36% (16/45) experienced a PSA decline of more than 0.8 ng/mL. Additionally, 73% (33/45) of patients exhibited an initial PSA reduction, though some showed later PSA increases, indicating the potential presence of undetected metastatic lesions. The median post-retreatment IPSS score was 4, significantly lower than scores reported in other treatment studies. Overall, 69% of patients reported mild urinary symptoms, with 96% (43/45) experiencing mild to moderate symptoms. Three patients experienced grade I or II proctitis, while one patient reported grade III proctitis. These findings suggest that regional organs, including the urethra, bladder, and rectum, demonstrate significant radiobiological recovery from prior radiation exposure, enabling tolerance to additional proton scanning beam therapy. Conclusions: This retrospective analysis of 45 patients with recurrent localized prostate cancer treated with salvage proton reirradiation demonstrates favorable outcomes, with a median follow-up of two years. The post-retreatment IPSS scores were comparable to those reported in follow-up studies of initial radiation therapy treatments, indicating stable or improved urinary symptoms compared to the end of initial treatment. These results highlight the efficacy of proton scanning beam therapy in providing effective salvage treatment while minimizing adverse effects on critical organs. The findings also enhance the understanding of radiobiological responses to reirradiation and support proton therapy as a viable option for patients with recurrent localized prostate cancer following previous definitive radiation therapy.

Keywords: prostate salvage radiotherapy, proton therapy, biological radiation tolerance, radiobiology of organs

Procedia PDF Downloads 19

Authors: Maria Cardova

Abstract:

Aim and objectives: The purpose of this studywas to explore to what extent the deprivation statusinfluenced children’s physical activity, dietary behaviour, and health outcomes such as weight status. Background: The United Kingdom’s childhood obesity rates are currently ranked among the highest in Europe. North West England deals with highest rates of childhood obesity. Data from the UK Millennium Cohort Study suggested a deprivation gradient to childhood obesity in England, with obesity rates being the highest in the most deprived areas. Traditionally, it has been individual conception of health, but the contemporary stance is that health behaviours affecting obesity are influenced by a broad range of factors operating at multiple levels. According to socio-ecological model of health behaviour, differences in obesity rates and health outcomes are likely explained by differences in lifestyle behaviours including physical activity and diet behaviours. However, higher rates of obesity among deprived children are not due to physical inactivity, in fact, most socially disadvantaged children are the most physically active. Poor diet including high consumption of fast food and sugar-sweetened beverages and low consumption of fruit and vegetables was found to be the most prevalent among adolescents living in poverty. Methods: This study adopted quantitative approach. It consisted of combination of basic demographic data, anthropometry, and questionnaires. Children (N = 165, mean age = 10.04 years; 53.33% female; 46.66% male) completed survey packs during school day including KIDSCREEN, Youth Activity Profile, Beverage and Snack Questionnaire, and Child Body Image Scale questionnaires as well as had anthropometric measurements taken including Body mass index, waist circumference, weight, and height. Children’s deprivation status was based on the English Indices of Multiple Deprivation scores of the school they attended. Results: Children from more deprived areas had higher weight status, waist circumference. Deprivation status had also effect on some dimensions of the KIDSCREEN questionnaire, such as that those from more deprived areas felt less socially accepted and bullied by their peers, had worse feelings about themselves such as body image, and more difficulty with school and learning. Children from more deprived areas reported higher rates of physical activity and also differences in snack and fruit and vegetable intake than their more affluent peers. Conclusion: Results demonstrated that, children living in the most-deprived areas appear to be at greater risk of unfavourable health-related variables and behaviours and are exposed to home and neighbourhood environments that are less conducive to health-promoting behaviours compared to their peers from less deprived areas. These findings indicate that children living in highly deprived areas represent an important group for future interventions designed to promote health-behaviours that would impact on the quality of life of the child and other health variables such as weight status.

Keywords: children, dietary behaviour, health, obesity, physical Activity, weight Status

Procedia PDF Downloads 137

Authors: O. Gsib, U. Peirera, C. Egles, S. A. Bencherif

Abstract:

In skin regenerative medicine, one of the critical issues is to produce a three-dimensional scaffold with optimized porosity for dermal fibroblast infiltration and neovascularization, which exhibits high mechanical properties and displays sufficient wound healing characteristics. In this study, we report on the synthesis and characterization of macroporous sequential interpenetrating polymer networks (IPNs) combining skin wound healing properties of fibrin with the excellent physical properties of polyethylene glycol (PEG). Fibrin fibers serve as a provisional biologically active network to promote cell adhesion and proliferation while PEG provides the mechanical stability to maintain the entire 3D construct. After having modified both PEG and Serum Albumin (used for promoting enzymatic degradability) by adding methacrylate residues (PEGDM and SAM, respectively), Fibrin/PEGDM-SAM sequential IPNs were synthesized as follows: Macroporous sponges were first produced from PEGDM-SAM hydrogels by a freeze-drying technique and then rehydrated by adding the fibrin precursors. Environmental Scanning Electron Microscopy (ESEM) and Confocal Laser Scanning Microscopy (CLSM) were used to characterize their microstructure. Human dermal fibroblasts were cultivated during one week in the constructs and different cell culture parameters (viability, morphology, proliferation) were evaluated. Subcutaneous implantations of the scaffolds were conducted on five-week old male nude mice to investigate their biocompatibility in vivo. We successfully synthesized interconnected and macroporous Fibrin/PEGDM-SAM sequential IPNs. The viability of primary dermal fibroblasts was well maintained (above 90%) after 2 days of culture. Cells were able to adhere, spread and proliferate in the scaffolds suggesting the suitable porosity and intrinsic biologic properties of the constructs. The fibrin network adopted a spider web shape that covered partially the pores allowing easier cell infiltration into the macroporous structure. To further characterize the in vitro cell behavior, cell proliferation (EdU incorporation, MTS assay) is being studied. Preliminary histological analysis of animal studies indicated the persistence of hydrogels even after one-month post implantation and confirmed the absence of inflammation response, good biocompatibility and biointegration of our scaffolds within the surrounding tissues. These results suggest that our Fibrin/PEGDM-SAM IPNs could be considered as potential candidates for dermis regenerative medicine. Histological analysis will be completed to further assess scaffold remodeling including de novo extracellular matrix protein synthesis and early stage angiogenesis analysis. Compression measurements will be conducted to investigate the mechanical properties.

Keywords: fibrin, hydrogels for dermal reconstruction, polyethylene glycol, semi-interpenetrating polymer network

Procedia PDF Downloads 237

Authors: Nikeshala Weerasekara, Roshan Ajward

Abstract:

Contemporary business environment, given the circumstance of stringent scrutiny toward corporate behavior, organizations are under pressure to develop and implement solid overarching Corporate Social Responsibility (CSR) strategies. In that milieu, in order to differentiate themselves from competitors and maintain stakeholder confidence banks spend millions of dollars on CSR programmes. However, knowledge on how non-western bank employees perceive such activities is inconclusive. At the same time recently only researchers have shifted their focus on positive effects of compassion at work or the organizational conditions under which it arises. Nevertheless, mediation mechanisms between CSR and compassion at work have not been adequately examined leaving a vacuum to be explored. Despite finding a purpose in work that is greater than extrinsic outcomes of the work is important to employees, meaningful work has not been examined adequately. Thus, in addition to examining the direct relationship between CSR and compassion at work, this study examined the mediating capability of meaningful work between these variables. Specifically, the researcher explored how CSR enables employees to sense work as meaningful which in turn would enhance their level of compassion at work. Hypotheses were developed to examine the direct relationship between CSR and compassion at work and the mediating effect of meaningful work on the relationship between CSR and compassion at work. Both Social Identity Theory (SIT) and Social Exchange Theory (SET) were used to theoretically support the relationships. The sample comprised of 450 respondents covering different levels of the bank. A convenience sampling strategy was used to secure responses from 13 local licensed commercial banks in Sri Lanka. Data was collected using a structured questionnaire which was developed based on a comprehensive review of literature and refined using both expert opinions and a pilot survey. Structural equation modeling using Smart Partial Least Square (PLS) was utilized for data analysis. Findings indicate a positive and significant (p < .05) relationship between CSR and compassion at work. Also, it was found that meaningful work partially mediates the relationship between CSR and compassion at work. As per the findings it is concluded that bank employees’ perception of CSR engagement not only directly influence compassion at work but also impact such through meaningful work as well. This implies that employees consider working for a socially responsible bank since it creates greater meaningfulness of work to retain with the organization, which in turn trigger higher level of compassion at work. By utilizing both SIT and SET in explaining relationships between CSR and compassion at work it amounts to theoretical significance of the study. Enhance existing literature on CSR and compassion at work. Also, adds insights on mediating capability of psychologically related variables such as meaningful work. This study is expected to have significant policy implications in terms of increasing compassion at work where managers must understand the importance of including CSR activities into their strategy in order to thrive. Finally, it provides evidence of suitability of using Smart PLS to test models with mediating relationships involving non normal data.

Keywords: compassion at work, corporate social responsibility, employee commitment, meaningful work, positive affect

Procedia PDF Downloads 129

Authors: Habiba Nahzat, Karen Crow, Lisa Manuel, Maria Huijbregts

Abstract:

Background and Rationale: The World Health Organization (WHO) declared COVID-19 a pandemic on March 11, 2020. Shortly after, the Ontario provincial and Toronto municipal governments also released multiple directives that led to the mass closure of businesses both in the public and private sectors. Recent research has identified connections between Intimate Partner Violence (IPV) and COVID-19 related stressors - especially because of lockdown and social isolation measures. Psychological impacts of lengthy seclusion coupled with disconnection from extended family and diminished support services can take a toll on families at risk and may increase mental health issues and the prevalence of IPV. Research Question: Thus, the purpose of the study was to understand the perspective of the Violence Against Women (VAW) program staff on the impact of the COVID-19 pandemic; we especially wanted to understand staff views of restrictions on clients’ counseling experiences and the ability to access services in general. The study also aimed to examine VAW program staff experiences regarding remote work and explore how the pandemic restriction measures affected the ability of their program operations to support their clients and each other. Method: A cross-sectional, descriptive qualitative study was conducted with a purposive sample of 9 VAW program staff – eight VAW counselors and one VAW manager. Prior to data collection, program staff collaborated in the development of the study purpose, interview questions and methodology. Ethics approval was obtained from the sponsoring organization’s Research Ethics Board. In-depth individual interviews were conducted with study participants using a semi-structured interview questionnaire. Brief demographic information was also collected prior to the interview. Descriptive statistics were used to analyze quantitative data and qualitative data was analyzed by thematic content analysis. Results: Findings from this study indicate that the COVID-19 pandemic restrictions had an adverse impact on clients seeking VAW services based on VAW staff perspectives. Program staff reported a perceived increase in abuse among women, especially in emotional and financial abuse and experiences of isolation and trauma. Findings further highlight the challenges women experienced when trying to access services in general as well as counseling and legal services. This was perceived to be more prominent among newcomers and marginalized women. The study also revealed client and staff challenges when participating in virtual counseling, their innovations and clients’ creativity in accessing needed counseling and how staff over time adapted to providing virtual support during the pandemic. Conclusion and Next Steps: This study builds upon existing evidence on the impact of COVID-19 restrictions on VAW and may inform future research to better understand the association between the COVID-19 pandemic restrictions and VAW on a broader scale and to inform and support possible short-term and long-term changes in the client experience and counselling practice.

Keywords: COVID-19, pandemic, virtual, violence against women (VAW)

Procedia PDF Downloads 190

Authors: Teresa Rushe, Nicole Devlin, Tara O Neill

Abstract:

In this study, we sought to examine associations between childhood experiences of community and collective violence and psychological functioning in young people who grew up in post-conflict Northern Ireland. We hypothesized that those who grew up with such experiences would demonstrate internalizing and externalizing difficulties in early adulthood and, furthermore, that these difficulties would be mediated by adverse childhood experiences occurring within the home environment. As part of the Northern Ireland Childhood Adversity Study, we recruited 213 young people aged 18-25 years (108 males) who grew up in the post-conflict society of Northern Ireland using purposive sampling. Participants completed a digital questionnaire to measure adverse childhood experiences as well as aspects of psychological functioning. We employed the Adverse Childhood Experience -International Questionnaire (ACE-IQ¬) adaptation of the original Adverse Childhood Experiences Questionnaire (ACE) as it additionally measured aspects of witnessing community violence (e.g., seeing someone being beaten/killed, fights) and experiences of collective violence (e.g., war, terrorism, police, or gangs’ battles exposure) during the first 18 years of life. 51% of our sample reported experiences of community and/or collective violence (N=108). Compared to young people with no such experiences (N=105), they also reported significantly more adverse experiences indicative of household dysfunction (e.g., family substance misuse, mental illness or domestic violence in the family, incarceration of a family member) but not more experiences of abuse or neglect. As expected, young people who grew up with the community and/or collective violence reported significantly higher anxiety and depression scores and were more likely to engage in acts of deliberate self-harm (internalizing symptoms). They also started drinking and taking drugs at a younger age and were significantly more likely to have been in trouble with the police (externalizing symptoms). When the type of violence exposure was separated by whether the violence was witnessed (community violence) or more directly experienced (collective violence), we found community and collective violence to have similar effects on externalizing symptoms, but for internalizing symptoms, we found evidence of a differential effect. Collective violence was associated with depressive symptoms, whereas witnessing community violence was associated with anxiety-type symptoms and deliberate self-harm. However, when experiences of household dysfunction were entered into the models predicting anxiety, depression, and deliberate self-harm, none of the main effects remained significant. This suggests internalizing type symptoms are mediated by immediate family-level experiences. By contrast, significant community and collective violence effects on externalizing behaviours: younger initiation of alcohol use, younger initiation of drug use, and getting into trouble with the police persisted after controlling for family-level factors and thus are directly associated with growing up with the community and collective violence. Given the cross-sectional nature of our study, we cannot comment on the direction of the effect. However, post-hoc correlational analyses revealed associations between externalising behaviours and personal factors, including greater risk-taking and young age at puberty. The implications of the findings will be discussed in relation to interventions for young people and families living with the community and collective violence.

Keywords: community and collective violence, adverse childhood experiences, youth, psychological wellbeing

Procedia PDF Downloads 85

Authors: Nadezhda F. Mikahailova, Margarita E. Fattakhova, Mirgarita A. Mironova, Ekaterina V. Vyacheslavova, Vladimir A. Mikahailov

Abstract:

Stigma is a significant obstacle to the successful adaptation of deaf students to the conditions of an educational institution, especially for those who study in inclusion. The aim of the study was to identify the spheres of life which are the most significant for developing of the stigma of deaf students; to assess the influence of factors associated with deafness on the degree of their self-stigmatization (time and degree of hearing loss, type of education - inclusion / differentiation) and to find out who is more prone to stigma - which characteristics of personality, identity, mental health and coping are specific for those deaf who demonstrates stigmatizing attitudes. The study involved 154 deaf and hard-of-hearing students (85 male and 69 female) aged from 18 to 45 years - 28 students of the Herzen State Pedagogical University (St. Petersburg), who study in inclusion, 108 students of the National Research Technological University and 18 students of the Aviation Technical College (Kazan) - students in groups with a sign language interpreter. We used the following methods: modified questionnaire 'Self-assessment and coping strategies' (Jambor & Elliot, 2005), Scale of self-esteem (Rosenberg et al, 1995), 'Big-Five' (Costa&McCrae, 1997), TRF (Becker, 1989), WCQ (Lazarus & Folkman, 1988), self-stigma scale (Mikhailov, 2008). The severity of self-stigmatization of deaf and hard of hearing students was determined by the degree of deafness and the time they live with hearing loss, learning conditions, the type of self-identification (acculturation), personality traits, and the specifics of coping behavior. Persons with congenital hearing loss more often noted a benevolent and sympathetic attitude towards them on the part of the hearers and less often, due to deafness, limited themselves to visiting public places than late deaf people, which indicates 'get rid of' the experience of their defect and normalization of the state. Students studying in conditions of inclusion more often noted the dismissive attitude of society towards deaf people. Individuals with mild to moderate hearing loss were more likely to fear marriage and childbearing because of their deafness than students with profound hearing loss. Those who considered themselves disabled (49% of all respondents) were more inclined to cope with seeking social support and less used 'distancing' coping. Those who believed that their quality of life and social opportunities were most influenced by the attitude of society towards the deaf (39%) were distinguished by a less pronounced sense of self-worth, a desire for autonomy, and frequent usage of 'avoidance' coping strategies. 36.4% of the respondents noted that there have been situations in their lives when people learned that they are deaf, began to treat them worse. These respondents had predominantly deaf acculturation, but more often, they used 'bicultural skills,' specific coping for the deaf, and had a lower level of extraversion and emotional stability. 31.2% of the respondents tried to hide from others that they have hearing problems. They considered themselves to be in a culture of hearing, used coping strategies 'bicultural skills,' and had lower levels of extraversion, cooperation, and emotional stability. Acknowledgment: Supported by the RFBR № 19-013-0040

Keywords: acculturation, coping, deafness, stigmatization

Procedia PDF Downloads 236

Authors: Carlos Amnael Orozco-Diaz, Robert David Moorehead, Gwendolen Reilly, Fiona Gilchrist, Cheryl Ann Miller

Abstract:

The current gold-standard for maxillofacial reconstruction surgery (MRS) utilizes auto-grafted cancellous bone as a filler. This study was aimed towards developing a polylactic-acid/hydroxyapatite (PLA-HA) composite suitable for fused-deposition 3D printing. Functionalization of the polymer through the addition of HA was directed to promoting bone-regeneration properties so that the material can rival the performance of cancellous bone grafts in terms of bone-lesion repair. This kind of composite enables the production of MRS implants based off 3D-reconstructions from image studies – namely computed tomography – for anatomically-correct fitting. The present study encompassed in-vitro degradation and in-vitro biocompatibility profiling for 3D-printed PLA and PLA-HA composites. PLA filament (Verbatim Co.) and Captal S hydroxyapatite micro-scale HA powder (Plasma Biotal Ltd) were used to produce PLA-HA composites at 5, 10, and 20%-by-weight HA concentration. These were extruded into 3D-printing filament, and processed in a BFB-3000 3D-Printer (3D Systems Co.) into tensile specimens, and were mechanically challenged as per ASTM D638-03. Furthermore, tensile specimens were subjected to accelerated degradation in phosphate-buffered saline solution at 70°C for 23 days, as per ISO-10993-13-2010. This included monitoring of mass loss (through dry-weighing), crystallinity (through thermogravimetric analysis/differential thermal analysis), molecular weight (through gel-permeation chromatography), and tensile strength. In-vitro biocompatibility analysis included cell-viability and extracellular matrix deposition, which were performed both on flat surfaces and on 3D-constructs – both produced through 3D-printing. Discs of 1 cm in diameter and cubic 3D-meshes of 1 cm3 were 3D printed in PLA and PLA-HA composites (n = 6). The samples were seeded with 5000 MG-63 osteosarcoma-like cells, with cell viability extrapolated throughout 21 days via resazurin reduction assays. As evidence of osteogenicity, collagen and calcium deposition were indirectly estimated through Sirius Red staining and Alizarin Red staining respectively. Results have shown that 3D printed PLA loses structural integrity as early as the first day of accelerated degradation, which was significantly faster than the literature suggests. This was reflected in the loss of tensile strength down to untestable brittleness. During degradation, mass loss, molecular weight, and crystallinity behaved similarly to results found in similar studies for PLA. All composite versions and pure PLA were found to perform equivalent to tissue-culture plastic (TCP) in supporting the seeded-cell population. Significant differences (p = 0.05) were found on collagen deposition for higher HA concentrations, with composite samples performing better than pure PLA and TCP. Additionally, per-cell-calcium deposition on the 3D-meshes was significantly lower when comparing 3D-meshes to discs of the same material (p = 0.05). These results support the idea that 3D-printable PLA-HA composites are a viable resorbable material for artificial grafts for bone-regeneration. Degradation data suggests that 3D-printing of these materials – as opposed to other manufacturing methods – might result in faster resorption than currently-used PLA implants.

Keywords: bone regeneration implants, 3D-printing, in vitro testing, biocompatibility, polymer degradation, polymer-ceramic composites

Procedia PDF Downloads 155

Authors: Ernest Moles, Patricia Urbán, María Belén Jiménez-Díaz, Sara Viera-Morilla, Iñigo Angulo-Barturen, Maria Antònia Busquets, Xavier Fernàndez-Busquets

Abstract:

Bearing in mind the absence of an effective vaccine against malaria and its severe clinical manifestations causing nearly half a million deaths every year, this disease represents nowadays a major threat to life. Besides, the basic rationale followed by currently marketed antimalarial approaches is based on the administration of drugs on their own, promoting the emergence of drug-resistant parasites owing to the limitation in delivering drug payloads into the parasitized erythrocyte high enough to kill the intracellular pathogen while minimizing the risk of causing toxic side effects to the patient. Such dichotomy has been successfully addressed through the specific delivery of immunoliposome (iLP)-encapsulated antimalarials to Plasmodium falciparum-infected red blood cells (pRBCs). Unfortunately, this strategy has not progressed towards clinical applications, whereas in vitro assays rarely reach drug efficacy improvements above 10-fold. Here, we show that encapsulation efficiencies reaching >96% can be achieved for the weakly basic drugs chloroquine (CQ) and primaquine using the pH gradient active loading method in liposomes composed of neutrally charged, saturated phospholipids. Targeting antibodies are best conjugated through their primary amino groups, adjusting chemical crosslinker concentration to retain significant antigen recognition. Antigens from non-parasitized RBCs have also been considered as targets for the intracellular delivery of drugs not affecting the erythrocytic metabolism. Using this strategy, we have obtained unprecedented nanocarrier targeting to early intraerythrocytic stages of the malaria parasite for which there is a lack of specific extracellular molecular tags. Polyethylene glycol-coated liposomes conjugated with monoclonal antibodies specific for the erythrocyte surface protein glycophorin A (anti-GPA iLP) were capable of targeting 100% RBCs and pRBCs at the low concentration of 0.5 μM total lipid in the culture, with >95% of added iLPs retained into the cells. When exposed for only 15 min to P. falciparum in vitro cultures synchronized at early stages, free CQ had no significant effect over parasite viability up to 200 nM drug, whereas iLP-encapsulated 50 nM CQ completely arrested its growth. Furthermore, when assayed in vivo in P. falciparum-infected humanized mice, anti-GPA iLPs cleared the pathogen below detectable levels at a CQ dose of 0.5 mg/kg. In comparison, free CQ administered at 1.75 mg/kg was, at most, 40-fold less efficient. Our data suggest that this significant improvement in drug antimalarial efficacy is in part due to a prophylactic effect of CQ found by the pathogen in its host cell right at the very moment of invasion.

Keywords: immunoliposomal nanoparticles, malaria, prophylactic-therapeutic polyvalent activity, targeted drug delivery

Procedia PDF Downloads 377

Authors: Esther Gumboh

Abstract:

The police play a critical role in society and are an integral aspect of the rule of law. Equally, respect for human rights is an integral part of professional policing. In view of the vast powers that the police enjoy and the attendant risk of abuse and resulting human rights violations, the need for police accountability and civilian police oversight is internationally and regionally recognised. Policing oversight springs from the duty to investigate human rights violations. Those implicated in perpetrating or covering up violations must be disciplined or prosecuted to ensure effective accountability. Police accountability is particularly important in Malawi given the dark history of policing in the country during the 30-year dictatorial era under President Kamuzu Banda. Described as one of the most repressive regimes in Africa, the Banda administration was characterised by gross state-sponsored violence, repressive policing and human rights violations. Indeed, the police were involved in various forms of human rights abuse including arbitrary arrests and unlawful detentions, torture, and excessive use of force in conducting arrests and public order policing. This situation flourished within a culture of police impunity bolstered in part by the absence of clear oversight mechanisms for police accountability. In turn, there was immense public mistrust of the police. Unsurprisingly, the criminal justice system was one of the priority areas for reform when Malawi adopted its first democratic Constitution in 1994. Section 153 of the Constitution envisions a police service that is, for all intents and purposes, there to provide for the protection of public safety and the rights of persons in Malawi according to the prescriptions of the Constitution and any other law. This position reflects the view that the duty to protect and promote human rights is not incompatible with effective policing. Despite this, the police continue to engage in questionable behaviour in public order policing, excessive use of force, deaths in police custody, ill-treatment, torture and other forms of abuse including sexual abuse. Perpetrators of abuses are occasionally punished, but investigations are often delayed, abandoned, or remain inconclusive. Police accountability remains largely elusive. Commendably, the law does subject the police to significant oversight both internally and externally. However, until 2010, Malawi lacked a wholly independent civilian oversight mechanism specifically mandated to monitor the activities of the Malawi Police Service and held it accountable. This void has since been filled by the Independent Complaints Commission established under the Police Act. This is a positive development that reiterates Malawi’s commitment to the investigation of human rights violations by the police and to ending police impunity. This contribution examines the legal framework for this Commission to project the effectiveness of the Commission. While the framework looks promising on various fronts, there are potential challenges that lie ahead. Malawi must pre-emptively deal with these challenges carefully if the Commission is to have any practical significance in transforming police accountability in the country. Drawing on lessons from other jurisdictions like South Africa, the paper makes recommendations for legislative reform to strengthen the Commission’s framework.

Keywords: civilian policing oversight, Malawi, police, police accountability, policing, policing oversight

Procedia PDF Downloads 238

Authors: Clemens Bulitta, Sasan Sadrizadeh, Sebastian Buhl

Abstract:

Introduction: Ventilation technology in operating theatres (OT)is internationally regulated by dif-ferent standards, which define basic specifications for technical equipment and many times also the necessary operating and performance parameters. This confronts the operators of healthcare facilities with the question of finding the best ventilation and air conditioning system for the OT in order to achieve the goal of a large and robust surgicalworkzone with appropriate air quality and climate for patient safety and occupational health. Additionally, energy consumption and the potential need for clothing that limits transmission of bacteria must be considered as well as the total life cycle cost. However, the evaluation methodology of ventilation systems regarding these matters are still a topic of discussion. To date, there are neither any uniform standardized specifications nor any common validation criteria established. Thus, this study aimed to review data in the literature and add ourown research results to compare and assess the performance of different ventilations systems regarding infection preventive effects, energy efficiency, and staff comfort. Methods: We have conducted a comprehensive literature review on OT ventilation-related topics to understand the strengths and limitations of different ventilation systems. Furthermore, data from experimental assessments on OT ventilation systems at the University of Amberg-Weidenin Germany were in-cluded to comparatively assess the performance of Laminar Airflow (LAF), Turbulent Mixing Air-flow(TMA), and Temperature-controlled Airflow (TcAF) with regards to patient and occupational safety as well as staff comfort including indoor climate.CFD simulations from the Royal Institute of Technology in Sweden (KTH) were also studied to visualize the differences between these three kinds of ventilation systems in terms of the size of the surgical workzone, resilience to obstacles in the airflow, and energy use. Results: A variety of ventilation concepts are in use in the OT today. Each has its advantages and disadvantages, and thus one may be better suited than another depend-ing on the built environment and clinical workflow. Moreover, the proper functioning of OT venti-lation is also affected by multiple external and internal interfering factors. Based on the available data TcAF and LAF seem to provide the greatest effects regarding infection control and minimizing airborne risks for surgical site infections without the need for very tight surgical clothing systems. Resilience to obstacles, staff comfort, and energy efficiency seem to be favourable with TcAF. Conclusion: Based on literature data in current publications and our studies at the Technical Uni-versity of Applied Sciences Amberg-Weidenand the Royal Institute of Technoclogy, LAF and TcAF are more suitable for minimizing the risk for surgical site infections leading to improved clin-ical outcomes. Nevertheless, regarding the best management of thermal loads, atmosphere, energy efficiency, and occupational safety, overall results and data suggest that TcAF systems could pro-vide the economically most efficient and clinically most effective solution under routine clinical conditions.

Keywords: ventilation systems, infection control, energy efficiency, operating theatre, airborne infection risks

Procedia PDF Downloads 99

Authors: Roberta Pecoraro, Elena Maria Scalisi

Abstract:

Engineered Nanoparticles (ENPs) and Nanomaterials (ENMs) concern an active research area and a sector in full expansion. They have physical-chemical characteristics and small size that improve their performance compared to common materials. Due to the increase in their production and their subsequent release into the environment, new strategies are emerging to assess risk of nanomaterials. NPs can be released into the environment through aquatic systems by human activities and exert toxicity on living organisms. We evaluated the potential toxic effect of cerium oxide (CeO2) nanoparticles because it’s used in different fields due to its peculiar properties. In order to assess nanoparticles toxicity, Fish Embryo Toxicity (FET) test was performed. Powders of CeO2 NPs supplied by the CNR-IMM of Catania are indicated as CeO2 type 1 (as-prepared) and CeO2 type 2 (modified), while CeO2 type 3 (commercial) is supplied by Sigma-Aldrich. Starting from a stock solution (0.001g/10 ml dilution water) of each type of CeO2 NPs, the other concentration solutions were obtained adding 1 ml of the stock solution to 9 ml of dilution water, leading to three different solutions of concentration (10-4, 10-5, 10-6 g/ml). All the solutions have been sonicated to avoid natural tendency of NPs to aggregate and sediment. FET test was performed according to the OECD guidelines for testing chemicals using our internal protocol procedure. A number of eight selected fertilized eggs were placed in each becher filled with 5 ml of each concentration of the three types of CeO2 NPs; control samples were incubated only with dilution water. Replication was performed for each concentration. During the exposure period, we observed four endpoints (embryo coagulation, lack of formation of somites, failure to lift the yolk bag, no heartbeat) by a stereomicroscope every 24 hours. Immunohistochemical analysis on treated larvae was performed to evaluate the expression of metallothioneins (MTs), Heat Shock Proteins 70 (HSP70) and 7-ethoxyresorufin-O-diethylase (EROD). Our results have not shown evident alterations on embryonic development because all embryos completed the development and the hatching of the eggs, started around the 48th hour after exposure, took place within the last observation at 72 hours. A good reactivity, both in the embryos and in the newly hatched larvae, was found. The presence of heartbeat has also been observed in embryos with reduced mobility confirming their viability. A higher expression of EROD biomarker was observed in the larvae exposed to the three types of CeO2, showing a clear difference with the control. A weak positivity was found for MTs biomarker in treated larvae as well as in the control. HSP70 are expressed homogeneously in all the type of nanoparticles tested but not too much greater than control. Our results are in agreement with other studies in the literature, in which the exposure of Danio rerio larvae to other metal oxide nanoparticles does not show adverse effects on survival and hatching time. Further studies are necessary to clarify the role of these NPs and also to solve conflicting opinions.

Keywords: Danio rerio, endpoints, fish embryo toxicity test, metallic nanoparticles

Procedia PDF Downloads 134

Authors: Duwage C. Perera, Ravisha N. Mudalige, Jay N. Meegoda

Abstract:

Per- and polyfluoroalkyl substances (PFAS), often referred to as "forever chemicals," are a class of environmentally persistent pollutants known for their exceptional chemical stability and resistance to conventional degradation methods. Among the various PFAS compounds, perfluorooctanoic acid (PFOA) has emerged as a priority contaminant due to its widespread occurrence, bioaccumulative nature, and toxicological effects on human health and ecosystems. The need for effective remediation strategies has driven significant interest in understanding the interactions between PFOA and potential adsorbent materials such as soils and sediments at the molecular level. In this study, density functional theory (DFT) is employed to investigate the adsorption mechanisms of PFOA on kaolinite, a naturally abundant clay mineral with promising applications in PFAS remediation. The computational approach involves constructing atomistic models of the kaolinite (001) surface to capture its unique structural and chemical characteristics. Both the tetrahedral (Si-O) and octahedral (Al-O) layers of kaolinite are included in the models, with varying degrees of surface hydroxylation to simulate environmentally relevant conditions. PFOA is modeled in both protonated and deprotonated states, reflecting its behavior under different pH levels commonly encountered in natural and engineered systems. The adsorption energies are calculated to quantify the affinity of PFOA for kaolinite, while Bader charge analysis is conducted to examine charge redistribution and electrostatic interactions during the adsorption process. A detailed investigation of the molecular interactions between PFOA and kaolinite reveals the critical role of hydrogen bonding, van der Waals forces, and electrostatic interactions in PFOA adsorption. The carboxylic group of PFOA demonstrates strong binding to hydroxylated sites on the kaolinite surface, while the hydrophobic tail of PFOA interacts minimally with the mineral, reflecting its dual hydrophilic-hydrophobic nature. Vibrational frequency analysis is performed to identify shifts in the functional group vibrations, providing additional evidence of strong chemical interactions between PFOA and kaolinite. This study provides a comprehensive understanding of the molecular-level interactions governing PFOA adsorption on kaolinite. By elucidating the underlying mechanisms, it establishes a foundation for the design and optimization of clay-based remediation technologies aimed at mitigating PFAS contamination in environmental systems. Future work integrating experimental validation with the computational insights presented here will further enhance the applicability of kaolinite and other clay minerals in PFAS remediation efforts, addressing a critical global environmental challenge.

Keywords: adsorption mechanism, carbon-fluorine bond stability, density functional theory, kaolinite adsorption, perfluorooctanoic acid, PFAS, soil and water contamination

Procedia PDF Downloads 3

Authors: Lillian M. Seo, Curtis L. Petersen, Ryan J. Halter, David Kotz, John A. Batsis

Abstract:

Background: Resistance-based exercises effectively enhance muscle strength, which is especially important in older populations as it reduces the risk of disability. Our group developed a Bluetooth-enabled handle for resistance exercise bands that wirelessly transmits relative force data through low-energy Bluetooth to a local smartphone or similar device. The system has the potential to measure home-based exercise interventions, allowing health professionals to monitor compliance. Its feasibility has already been demonstrated in both clinical and field-based settings, but it remained unclear whether the system’s usability persisted upon repeated use. The current study sought to assess the usability of this system and its users’ satisfaction with repeated use by deploying the device among younger adults to gather formative information that can ultimately improve the device’s design for older adults. Methods: A usability study was conducted in which 32 participants used the above system. Participants executed 10 repetitions of four commonly performed exercises: bicep flexion, shoulder abduction, elbow extension, and triceps extension. Each completed three exercise sessions, separated by at least 24 hours to minimize muscle fatigue. At its conclusion, subjects completed an adapted version of the usefulness, satisfaction, and ease (USE) questionnaire – assessing the system across four domains: usability, satisfaction, ease of use, and ease of learning. The 20-item questionnaire examined how strongly a participant agrees with positive statements about the device on a seven-point Likert scale, with one representing ‘strongly disagree’ and seven representing ‘strongly agree.’ Participants’ data were aggregated to calculate mean response values for each question and domain, effectively assessing the device’s performance across different facets of the user experience. Summary force data were visualized using a custom web application. Finally, an optional prompt at the end of the questionnaire allowed for written comments and feedback from participants to elicit qualitative indicators of usability. Results: Of the n=32 participants, 13 (41%) were female; their mean age was 32.4 ± 11.8 years, and no participants had a physical impairment. No usability questions received a mean score < 5 of seven. The four domains’ mean scores were: usefulness 5.66 ± 0.35; satisfaction 6.23 ± 0.06; ease of use 6.25 ± 0.43; and ease of learning 6.50 ± 0.19. Representative quotes of the open-ended feedback include: ‘A non-rigid strap-style handle might be useful for some exercises,’ and, ‘Would need different bands for each exercise as they use different muscle groups with different strength levels.’ General impressions were favorable, supporting the expectation that the device would be a useful tool in exercise interventions. Conclusions: A simple usability assessment of a Bluetooth-enabled resistance exercise band supports a consistent and positive user experience among young adults. This study provides adequate formative data, assuring the next steps can be taken to continue testing and development for the target population of older adults.

Keywords: Bluetooth, exercise, mobile health, mHealth, usability

Procedia PDF Downloads 117

Authors: Zeradam Yeshiwas, A. Krishnaia

Abstract:

The aim of this study is to verify the resulting surface roughness of parts formed by the Single-Point Incremental Forming (SPIF) process for an ISO 3574 Drawing Quality Cold Rolled CR2 Steel. The chemical composition of drawing quality Cold Rolled CR2 steel is comprised of 0.12 percent of carbon, 0.5 percent of manganese, 0.035 percent of sulfur, 0.04 percent phosphorous, and the remaining percentage is iron with negligible impurities. The experiments were performed on a 3-axis vertical CNC milling machining center equipped with a tool setup comprising a fixture and forming tools specifically designed and fabricated for the process. The CNC milling machine was used to transfer the tool path code generated in Mastercam 2017 environment into three-dimensional motions by the linear incremental progress of the spindle. The blanks of Drawing Quality Cold Rolled CR2 steel sheets of 1 mm of thickness have been fixed along their periphery by a fixture and hardened high-speed steel (HSS) tools with a hemispherical tip of 8, 10 and 12mm of diameter were employed to fabricate sample parts. To investigate the surface roughness, hyperbolic-cone shape specimens were fabricated based on the chosen experimental design. The effect of process parameters on the surface roughness was studied using three important process parameters, i.e., tool diameter, feed rate, and step depth. In this study, the Taylor-Hobson Surtronic 3+ surface roughness tester profilometer was used to determine the surface roughness of the parts fabricated using the arithmetic mean deviation (Rₐ). In this instrument, a small tip is dragged across a surface while its deflection is recorded. Finally, the optimum process parameters and the main factor affecting surface roughness were found using the Taguchi design of the experiment and ANOVA. A Taguchi experiment design with three factors and three levels for each factor, the standard orthogonal array L9 (3³) was selected for the study using the array selection table. The lowest value of surface roughness is significant for surface roughness improvement. For this objective, the ‘‘smaller-the-better’’ equation was used for the calculation of the S/N ratio. The finishing roughness parameter Ra has been measured for the different process combinations. The arithmetic means deviation (Rₐ) was measured via the experimental design for each combination of the control factors by using Taguchi experimental design. Four roughness measurements were taken for a single component and the average roughness was taken to optimize the surface roughness. The lowest value of Rₐ is very important for surface roughness improvement. For this reason, the ‘‘smaller-the-better’’ Equation was used for the calculation of the S/N ratio. Analysis of the effect of each control factor on the surface roughness was performed with a ‘‘S/N response table’’. Optimum surface roughness was obtained at a feed rate of 1500 mm/min, with a tool radius of 12 mm, and with a step depth of 0.5 mm. The ANOVA result shows that step depth is an essential factor affecting surface roughness (91.1 %).

Keywords: incremental forming, SPIF, drawing quality steel, surface roughness, roughness behavior

Procedia PDF Downloads 62

Authors: Junali Deka

Abstract:

“Pictures speak more than a thousand words”. It is the power of image which can have multiple meanings the way it is read by the viewers. This research article is an outcome of the extensive study of the phenomenon of‘selfie culture’ and dire need of self-constructed virtual identity among youths. In the recent times, there has been a revolutionary change in the concept of photography in terms of both techniques and applications. The popularity of ‘self-portraits’ mainly depend on the temporal space and time created on social networking sites like Facebook, Instagram. With reference to Stuart’s Hall encoding and decoding process, the article studies the behavior of the users who post photographs online. The photographic messages (Roland Barthes) are interpreted differently by different viewers. The notion of ‘self’, ‘self-love and practice of looking (Marita Sturken) and ways of seeing (John Berger) got new definition and dimensional together. After Oscars Night, show host Ellen DeGeneres’s selfie created the most buzz and hype in the social media. The term was judged the word of 2013, and has earned its place in the dictionary. “In November 2013, the word "selfie" was announced as being the "word of the year" by the Oxford English Dictionary. By the end of 2012, Time magazine considered selfie one of the "top 10 buzzwords" of that year; although selfies had existed long before, it was in 2012 that the term "really hit the big time an Australian origin. The present study was carried to understand the concept of ‘selfie-bug’ and the phenomenon it has created among youth (especially students) at large in developing a pseudo-image of its own. The topic was relevant and gave a platform to discuss about the cultural, psychological and sociological implications of selfie in the age of digital technology. At the first level, content analysis of the primary and secondary sources including newspapers articles and online resources was carried out followed by a small online survey conducted with the help of questionnaire to find out the student’s view on selfie and its social and psychological effects. The newspapers reports and online resources confirmed that selfie is a new trend in the digital media and it has redefined the notion of beauty and self-love. The Facebook and Instagram are the major platforms used to express one-self and creation of virtual identity. The findings clearly reflected the active participation of female students in comparison to male students. The study of the photographs of few selected respondents revealed the difference of attitude and image building among male and female users. The study underlines some basic questions about the desire of reconstruction of identity among young generation, such as - are they becoming culturally narcissist; responsible factors for cultural, social and moral changes in the society, psychological and technological effects caused by Smartphone as well, culminating into a big question mark whether the selfie is a social signifier of identity construction.

Keywords: Culture, Narcissist, Photographs, Selfie

Procedia PDF Downloads 407

Authors: Akiko Ohta, Masahiro Minami, Yusra Qadir, Jennifer York

Abstract:

The Home Instruction for Parents of Preschool Youngsters (HIPPY) is a home instruction program for mothers of children 3 to 5 years old. Using role-play as a method of teaching, the participating mothers work with their home visitors and learn how to deliver the HIPPY curriculum to their children. Applying HIPPY, Reviving Hope and Home for High-risk Refugee Mothers Program (RHH) was created to provide more personalized peer support and to respond to ongoing settlement challenges for isolated and vulnerable Government Assisted Refugee (GAR) mothers. GARs often have greater needs and vulnerabilities than other refugee groups. While the support is available, they often face various challenges and barriers in starting their new lives in Canada, such as inadequate housing, low first-language literacy levels, low competency in English or French, and social isolation. The pilot project was operated by Mothers Matter Centre (MMC) from January 2019 to March 2021 in partnership with the Immigrant Services Society of BC (ISSofBC). The formative evaluation was conducted by a research team at Simon Fraser University. In order to provide more suitable support for GAR mothers, RHH intended to offer more flexibility in HIPPY delivery, supported by a home visitor, to meet the need of refugee mothers facing various conditions and challenges; to have a pool of financial resources to be used for the RHH families when necessitated during the program period; to have another designated staff member, called a community navigator, assigned to facilitate the support system for the RHH families in their settlement; to have a portable device available for each RHH mother to navigate settlement support resources; and to provide other variations of the HIPPY curriculum as an option for the RHH mothers, including a curriculum targeting pre-HIPPY age children. Reflections on each program component was collected from RHH mothers and staff members of MMC and ISSofBC, including frontline workers and management staff, through individual interviews and focus group discussions. Each of the RHH program components was analyzed and evaluated by applying Moore’s four domains framework to identify key information and generate new knowledge (data). To capture RHH mothers’ program experience more in depth based on their own reflections, the photovoice method was used. Some photos taken by the mothers will be shared to illustrate their RHH experience as part of their life stories. Over the period of the program, this evaluation observed how RHH mothers became more confident in various domains, such as communicating with others, taking public transportations alone, and teaching their own child(ren). One of the major factors behind the success was their home visitors’ flexibility and creativity to create a more meaningful and tailored approach for each mother, depending on her background and personal situation. The role of the community navigator was tested out and improved during the program period. The community navigators took the key role to assess the needs of the RHH families and connect them with community resources. Both the home visitors and community navigators were immigrant mothers themselves and owing to their dedicated care for the RHH mothers; they were able to gain trust and work closely and efficiently with RHH mothers.

Keywords: refugee mothers, settlement support, program evaluation, Canada

Procedia PDF Downloads 173

Authors: V. Rekha, Rama Pal

Abstract:

The study examines the degree and magnitude of wealth-based inequalities in child health and its determinants in India. Despite making strides in economic growth, India has failed to secure a better nutritional status for all the children. The country currently faces the double burden of malnutrition as well as the problems of overweight and obesity. Child malnutrition, obesity, unsafe water, sanitation among others are identified as the risk factors for Non-Communicable Diseases (NCDs). Eliminating malnutrition in all its forms will catalyse improved health and economic outcomes. The assessment of the distributive dimension of child health across various segments of the population is essential for effective policy intervention. The study utilises the fourth round of District Level Health Survey for 2012-13 to analyse the inequalities among children in the age group 0-14 years in Maharashtra, a state in the western region of India with a population of 11.24 crores which constitutes 9.3 percent of the total population of India. The study considers the extent of health inequality by state, districts, sector, age-groups, and gender. The z-scores of four child health outcome variables are computed to assess the nutritional status of pre-school and school children using WHO reference. The descriptive statistics, concentration curves, concentration indices, correlation matrix, logistic regression have been used to analyse the data. The results indicate that magnitude of inequality is higher in Maharashtra and child health inequalities manifest primarily among the weaker sections of society. The concentration curves show that there exists a pro-poor inequality in child malnutrition measured by stunting, wasting, underweight, anaemia and a pro-rich overweight inequality. The inequalities in anaemia are observably lower due to the widespread prevalence. Rural areas exhibit a higher incidence of malnutrition, but greater inequality is observed in the urban areas. Overall, the wealth-based inequalities do not vary significantly between age groups. It appears that there is no gender discrimination at the state level. Further, rural-urban differentials in gender show that boys from the rural area and girls living in the urban region experience higher disparities in health. The relative distribution of undernutrition across districts in Maharashtra reveals that malnutrition is rampant and considerable heterogeneity also exists. A negative correlation is established between malnutrition prevalence and human development indicators. The findings of logistic regression analysis reveal that lower economic status of the household is associated with a higher probability of being malnourished. The study recognises household wealth, education of the parent, child gender, and household size as factors significantly related to malnutrition. The results suggest that among the supply-side variables, child-oriented government programmes might be beneficial in tackling nutrition deficit. In order to bridge the health inequality gap, the government needs to target the schemes better and should expand the coverage of services.

Keywords: child health, inequality, malnutrition, obesity

Procedia PDF Downloads 148

Authors: Kai Warsoenke, Maik Mackiewicz

Abstract:

To achieve a high quality of assembled car body structures, tolerancing is used to ensure a geometric accuracy of the single car body parts. There are two main techniques to determine the required tolerances. The first is tolerance analysis which describes the influence of individually tolerated input values on a required target value. Second is tolerance synthesis to determine the location of individual tolerances to achieve a target value. Both techniques are based on classical statistical methods, which assume certain probability distributions. To ensure competitiveness in both saturated and dynamic markets, production processes in vehicle manufacturing must be flexible and efficient. The dimensional specifications selected for the individual body components and the resulting assemblies have a major influence of the quality of the process. For example, in the manufacturing of forming tools as operating equipment or in the higher level of car body assembly. As part of the metrological process monitoring, manufactured individual parts and assemblies are recorded and the measurement results are stored in databases. They serve as information for the temporary adjustment of the production processes and are interpreted by experts in order to derive suitable adjustments measures. In the production of forming tools, this means that time-consuming and costly changes of the tool surface have to be made, while in the body shop, uncertainties that are difficult to control result in cost-intensive rework. The stored measurement results are not used to intelligently design tolerances in future processes or to support temporary decisions based on real-world geometric data. They offer potential to extend the tolerancing methods through data analysis and machine learning models. The purpose of this paper is to examine real-world measurement data from individual car body components, as well as assemblies, in order to develop an approach for using the data in short-term actions and future projects. For this reason, the measurement data will be analyzed descriptively in the first step in order to characterize their behavior and to determine possible correlations. In the following, a database is created that is suitable for developing machine learning models. The objective is to create an intelligent way to determine the position and number of measurement points as well as the local tolerance range. For this a number of different model types are compared and evaluated. The models with the best result are used to optimize equally distributed measuring points on unknown car body part geometries and to assign tolerance ranges to them. The current results of this investigation are still in progress. However, there are areas of the car body parts which behave more sensitively compared to the overall part and indicate that intelligent tolerancing is useful here in order to design and control preceding and succeeding processes more efficiently.

Keywords: automotive production, machine learning, process optimization, smart tolerancing

Procedia PDF Downloads 117

Authors: E. O. Okan, A. Kepic, P. Williams

Abstract:

Iron oxide copper gold (IOCG) deposits constitute important sources of copper and gold in Australia especially since the discovery of the supergiant Olympic Dam deposits in 1975. They are considered to be metasomatic expressions of large crustal-scale alteration events occasioned by intrusive actions and are associated with felsic igneous rocks in most cases, commonly potassic igneous magmatism, with the deposits ranging from ~2.2 –1.5 Ga in age. For the past two decades, geological, geochemical and potential methods have been used to identify the structures hosting these deposits follow up by drilling. Though these methods have largely been successful for shallow targets, at deeper depth due to low resolution they are limited to mapping only very large to gigantic deposits with sufficient contrast. As the search for ore-bodies under regolith cover continues due to depletion of the near surface deposits, there is a compelling need to develop new exploration technology to explore these deep seated ore-bodies within 1-4km which is the current mining depth range. Seismic reflection method represents this new technology as it offers a distinct advantage over all other geophysical techniques because of its great depth of penetration and superior spatial resolution maintained with depth. Further, in many different geological scenarios, it offers a greater ‘3D mapability’ of units within the stratigraphic boundary. Despite these superior attributes, no arguments for crustal scale seismic surveys have been proposed because there has not been a compelling argument of economic benefit to proceed with such work. For the seismic reflection method to be used at these scales (100’s to 1000’s of square km covered) the technical risks or the survey costs have to be reduced. In addition, as most IOCG deposits have large footprint due to its association with intrusions and large fault zones; we hypothesized that these deposits can be found by mainly looking for the seismic signatures of intrusions along prospective structures. In this study, we present two of such cases: - Olympic Dam and Vulcan iron-oxide copper-gold (IOCG) deposits all located in the Gawler craton, South Australia. Results from our 2D modelling experiments revealed that seismic reflection surveys using 20m geophones and 40m shot spacing as an exploration tool for locating IOCG deposit is possible even when hosted in very complex structures. The migrated sections were not only able to identify and trace various layers plus the complex structures but also show reflections around the edges of intrusive packages. The presences of such intrusions were clearly detected from 100m to 1000m depth range without losing its resolution. The modelled seismic images match the available real seismic data and have the hypothesized characteristics; thus, the seismic method seems to be a valid exploration tool to find IOCG deposits. We therefore propose that 2D seismic survey is viable for IOCG exploration as it can detect mineralised intrusive structures along known favourable corridors. This would help in reducing the exploration risk associated with locating undiscovered resources as well as conducting a life-of-mine study which will enable better development decisions at the very beginning.

Keywords: crustal scale, exploration, IOCG deposit, modelling, seismic surveys

Procedia PDF Downloads 326

Authors: Archana Sharma, Vijayashree Nayak, Ashok Kumar

Abstract:

Three-dimensional matrices were fabricated from blend of natural-natural polymers like carrageenan-gelatin and synthetic -natural polymers such as PEG- gelatin (PEG of different molecular weights (2,000 and 6,000) using two different crosslinkers; glutaraldehyde and EDC-NHS by cryogelation technique. Blends represented a feasible approach to design 3-D scaffolds with controllable mechanical, physical and biochemical properties without compromising biocompatibility and biodegradability. These matrices possessed interconnected porous structure, good mechanical strength, biodegradable nature, constant swelling kinetics, ability to withstand high temperature and visco-elastic behavior. Hemocompatibility of cryogel matrices was determined by coagulation assays and hemolytic activity assay which demonstrated that these cryogels have negligible effects on coagulation time and have excellent blood compatibility. In vitro biocompatibility (cell-matrix interaction) inferred good cell adhesion, proliferation, and secretion of ECM on matrices. These matrices provide a microenvironment for the growth, proliferation, differentiation and secretion of ECM of different cell types such as IMR-32, C2C12, Cos-7, rat bone marrow derived MSCs and human bone marrow MSCs. Hoechst 33342 and PI staining also confirmed that the cells were uniformly distributed, adhered and proliferated properly on the cryogel matrix. An ideal scaffold used for tissue engineering application should allow the cells to adhere, proliferate and maintain their functionality. Neurotransmitter analysis has been done which indicated that IMR-32 cells adhered, proliferated and secreted neurotransmitters when they interacted with these matrices which showed restoration of their functionality. The cell-matrix interaction up to molecular level was also evaluated so to check genotoxicity and protein expression profile which indicated that these cryogel matrices are non-genotoxic and maintained biofunctionality of cells growing on these matrices. All these cryogels, when implanted subcutaneously in balb/c mice, showed no adverse systemic or local toxicity effects at implantation site. There was no significant increase in inflammatory cell count has otherwise been observed after scaffold implantation. These cryogels are supermacroporous and this porous structure allows cell infiltration and proliferation of host cells. This showed the integration and presence of infiltrated cells into the cryogel implants. Histological analysis confirmed that the implanted cryogels do not have any adverse effect in spite of host immune system recognition at the site of implantation, on its surrounding tissues and other vital host organs. In vivo biocompatibility study after in vitro biocompatibility analysis has also concluded that these synthesized cryogels act as important biological substitutes, more adaptable and appropriate for transplantation. Thus, these cryogels showed their potential for soft tissue engineering applications.

Keywords: cryogelation, hemocompatibility, in vitro biocompatibility, in vivo biocompatibility, soft tissue engineering applications

Procedia PDF Downloads 225

Authors: Aisling Gough, Ruth F. Hunter, Jianjun Tang, Sarah F. Brennan, Oliver Smith, Mark A. Tully, Chris Patterson, Alberto Longo, George Hutchinson, Lindsay Prior, David French, Jean Adams, Emma McIntosh, Frank Kee

Abstract:

Background: As a large proportion of the UK workforce is employed in sedentary occupations, worksite interventions have the potential to contribute significantly to the health of the population. The UK Government is currently encouraging the use of financial incentives to promote healthier lifestyles but there is a dearth of evidence regarding the effectiveness and sustainability of incentive schemes to promote physical activity in the workplace. Methods: A large cluster RCT is currently underway, incorporating nested behavioural economic field experiments and process evaluation, to evaluate the effectiveness of a Physical Activity Loyalty Scheme. Office-based employees were recruited from large public sector organisations in Lisburn and Belfast (Northern Ireland) and randomised to an Intervention or Control group. Participants in the Intervention Group were encouraged to take part in 150 minutes of physical activity per week through provision of financial incentives (retailer vouchers) to those who met physical activity targets throughout the course of the 6 month intervention. Minutes of physical activity were monitored when participants passed by sensors (holding a keyfob) placed along main walking routes, parks and public transport stops nearby their workplace. Participants in the Control Group will complete the same outcome assessments (waiting-list control). The primary outcome is steps per day measured via pedometers (7 days). Secondary outcomes include health and wellbeing (Short Form-8, EuroQol-5D-5L, Warwick Edinburgh Mental Well Being Scale), and work absenteeism and presenteeism. Data will be collected at baseline, 6, 12 and 18 months. Information on PAL card & website usage, voucher downloads and redemption of vouchers will also be collected as part of a comprehensive process evaluation. Results: In total, 853 participants have been recruited from 9 workplaces in Lisburn, 12 buildings within the Stormont Estate, Queen’s University Belfast and Belfast City Hospital. Participants have been randomised to intervention and control groups. Baseline and 6-month data for the Physical Activity Loyalty Scheme has been collected. Findings regarding the effectiveness of the intervention from the 6-month follow-up data will be presented. Discussion: This study will address the gap in knowledge regarding the effectiveness and cost-effectiveness of a workplace-based financial incentive scheme to promote a healthier lifestyle. As the UK workforce is increasingly sedentary, workplace-based physical activity interventions have significant potential in terms of encouraging employees to partake in physical activity during the working day which could lead to substantial improvements in physical activity levels overall. Implications: If a workplace based physical activity intervention such as this proves to be both effective and cost-effective, there is great potential to contribute significantly to the health and wellbeing of the workforce in the future. Workplace-based physical activity interventions have the potential to improve the physical and mental health of employees which may in turn lead to economic benefits for the employer, such as reduction in rates of absenteeism and increased productivity.

Keywords: behaviour change, cluster randomised controlled trial, loyalty scheme, physical activity

Procedia PDF Downloads 326

Authors: L. Kashyap, S. Jha, D. Shende, V. K. Mohan, P. Khanna, A. Aravindan, S. Kashyap, L. Singh, S. Aggarwal

Abstract:

Obesity is associated with a chronic inflammatory state. During surgery, there is an interplay between anaesthetic and surgical stress vis-a-vis the already present complex immune state. Moreover, the postoperative period is dictated by inflammation, which is crucial for wound healing and regeneration. An excess of inflammatory response might hamper recovery besides increasing the risk for infection and complications. There is definite evidence of the immunosuppressive role of inhaled anaesthetic agents. This immune modulation may be brought into effect directly by influencing the innate and adaptive immunity cells. The effects of propofol on immune mechanisms in has been widely elucidated because of its popularity. It reduces superoxide generation, elastase release, and chemotaxis. However, there is no unequivocal proof of one’s superiority over the other. Hence, an anaesthetic regimen with lesser inflammatory potential and specific to the obese patient is needed. OBESITA trial protocol (2019) by Sousa and co-workers in progress aims to test the hypothesis that anaesthesia with sevoflurane results in a weaker proinflammatory response compared to propofol, as evidenced by lower IL-6 and other biomarkers and an increased macrophage differentiation into M2 phenotype in adipose tissue. IL-6 was used as the objective parameter to evaluate inflammation as it is regulated by both surgery and anesthesia. It is the most sensitive marker of the inflammatory response to tissue damage since it is released within minutes by blood leukocytes. We hypothesized that maintenance of anaesthesia with propofol would lead to less inflammation than that with desflurane. Aims: The effect of two anaesthetic techniques, total intravenous anaesthesia (TIVA) with propofol and desflurane, on surgical stress response was evaluated. The primary objective was to compare serum interleukin-6 (IL-6) levels before and after surgery. Methods: In this prospective single-blinded randomized controlled trial undertaken, 30 obese patients (BMI>30 kg/m2) undergoing laparoscopic bariatric surgery under general anaesthesia were recruited. Patients were randomized to receive desflurane or TIVA using a target-controlled infusion for maintenance of anaesthesia. As a marker of inflammation, pre-and post-surgery IL-6 levels were compared. Results: After surgery, IL-6 levels increased significantly in both groups. The rise in IL-6 was less with TIVA than with desflurane; however, it did not reach significance. IL-6 rise post-surgery correlated positively with the complexity of procedure and duration of surgery and anaesthesia, rather than anaesthetic technique. Both groups did not differ in terms of intra-operative hemodynamic and respiratory variables, time to awakening, postoperative pulmonary complications, and duration of hospital stay. The incidence of nausea was significantly higher with desflurane than with TIVA. Conclusion: Inflammatory response did not differ as a function of anaesthetic technique when propofol and desflurane were compared. Also, patient and surgical variables dictated post-operative inflammation more than the anaesthetic factors. Further, larger sample size is needed to confirm or refute these findings.

Keywords: bariatric, biomarkers, inflammation, laparoscopy

Procedia PDF Downloads 123

Authors: Samantha Jeffries, Chontit Chuenurah

Abstract:

Thailand incarcerates the largest number of women and has the highest female incarceration rate in South East Asia. Since the 1990s, there has been a substantial increase in the number, rate and proportion of women imprisoned. Thailand places a high priority on the gender specific contexts out of which offending arises and the different needs of women in the criminal justice system. This is manifested in work undertaken to guide the development of the United Nations Rules for the Treatment of Women Prisoners and Non-Custodial Measures for Women Offenders (the Bangkok Rules); adopted by the United Nations General Assembly in 2010. The Bangkok Rules make a strong statement about Thailand’s recognition of and commitment to the fair and equitable treatment of women throughout their contact with the criminal justice system including at sentencing and in prison. This makes the comparatively high use of imprisonment for women in Thailand particularly concerning and raises questions about the relationship between gender, crime and criminal justice. While there is an extensive body of research in Western jurisdictions exploring women’s pathways to prison, there is a relative dearth of methodologically robust research examining the possible gendered circumstances leading to imprisonment in Thailand. In this presentation, we will report preliminary findings from a qualitative study of women’s pathways to prison in Thailand. Our research aims were to ascertain: 1) the type, frequency, and context of criminal behavior that led to women’s incarceration, 2) women’s experiences of the criminal justice system, 3) the broader life experiences and circumstances that led women to prison in Thailand. In-depth life history interviews (n=77) were utilized to gain a comprehensive understanding of women’s journeys into prison. The interview schedule was open-ended consisting of prisoner responses to broad discussion topics. This approach provided women with the opportunity to describe significant experiences in their lives, to bring together distinct chronologies of events, and to analyze links between their varied life experiences, offending, and incarceration. Analyses showed that women’s journey’s to prison take one of eight pathways which tentatively labelled as follows, the: 1) harmed and harming pathway, 2) domestic/family violence victimization pathway, 3) drug connected pathway, 4) street woman pathway, 5) economically motivated pathway, 6) jealousy anger and/or revenge pathway, 7) naivety pathway, 8) unjust and/or corrupted criminal justice pathway. Each will be fully discussed during the presentation. This research is significant because it is the first in-depth methodologically robust exploration of women’s journeys to prison in Thailand and one of a few studies to explore gendered pathways outside of western contexts. Understanding women’s pathways into Thailand’s prisons is crucial to the development of effective planning, policy and program responses not only while women are in prison but also post-release. To best meet women’s needs in prison and effectively support their reintegration, we must have a comprehensive understanding of who these women are, what offenses they commit, the reasons that trigger their confrontations with the criminal justice system and the impact of the criminal justice system on them.

Keywords: pathways, prison, women, Thailand

Procedia PDF Downloads 247

Authors: Bassem M. Darwish, Robert H. Ablove

Abstract:

Introduction: Total knee arthroscopy (TKA) is a commonly performed procedure in patients with end-stage osteoarthritis and inaccuracy of component alignment in TKA has been shown to have many adverse post-operative outcomes such as accelerated implant wear, reduced functional outcomes, and shorter overall implant survival. Robotic surgical systems have been introduced to try and improve joint alignment and functional outcomes in knee arthroscopy, one recent iteration is the ROSA knee system, released to the market in 2019. The objective of this scoping review is to map the available evidence, identify the current types of evidence, and identify knowledge gaps to guide future studies on patient outcomes following ROSA-assisted total knee arthroplasties. Methods: An electronic search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews. Search terms included ROSA, knee arthroscopy, osteoarthritis, robotic, and malalignment. Types of study participants included patients with osteoarthritis, ages 18 and older, male or female, who received manual TKA (mTKA) or ROSA-assisted TKA (rTKA), and human patients or cadavers. Published, peer-reviewed controlled trials, observational studies, and case series were included. Case reports were not included in article review. Resulting articles were first screened based on title and abstract. Articles meeting inclusion criteria based on title and abstract review then underwent full-text review by the same reviewer. Results: This scoping review identified 11 total studies, 3 prospective observational studies, and 8 retrospective observational studies - a total of 970 rTKA patients and 1745 mTKA patients. There were no case series or randomized controlled trials comparing rTKA and mTKA. Patient-centered outcomes showed promise for rTKA, where it frequently showed significantly favorable functional outcomes, measured via KOOS-JR, VAS, KSS, OKS, FJS, and PROMIS scores, at various times postoperatively. However, there was much discrepancy about which score yielded significance at which postoperative follow-up. Complication rates, reoperation rates, and LOS were very similar between mTKA and rTKA groups. Studies also showed rTKA had more accurate joint alignment within the 0 ± 3o corridor and had significantly higher rates of achieving postoperative joint angles similar to the preoperative plan. Finally, there was major agreement that rTKA cases take significantly longer time at the start, however, there is a rapid learning curve. Once past the learning curve, rTKA cases are performed in a similar time to mTKA and reduced physician stress and strain. Conclusion: The ROSA knee system represents a promising option for the management of osteoarthritis via total knee arthroscopy. The studies reviewed in this paper favor the patient-centered function outcomes, joint alignments, and physician health implications of the ROSA knee system to conventional total knee arthroscopy. Further study is warranted, however, to better understand recovery periods, longer-term functional outcomes, operative fatigue, and reduction in radiation exposure.

Keywords: arthroplasty, knee, robotics, malalignment

Procedia PDF Downloads 35

Authors: P. Ramesh, Aby Joseph, Arya G. Lal, U. S. Aji

Abstract:

Integration of distributed green renewable energy sources in addition with battery energy storage is an inevitable requirement in a smart grid environment. To achieve this, an Intelligent Green Energy Management System (i-GEMS) needs to be incorporated to ensure coordinated operation between supply and load demand based on the hierarchy of Renewable Energy Sources (RES), battery energy storage and distribution grid. A bi-directional energy harvester is an integral component facilitating Intelligent Green Energy Management System (i-GEMS) and it is required to meet the technical challenges mentioned as follows: (1) capability for bi-directional mode of operation (buck/boost) (2) reduction of circuit parasitic to suppress voltage spikes (3) converter startup problem (4) high frequency magnetics (5) higher power density (6) mode transition issues during battery charging and discharging. This paper is focused to address the above mentioned issues and targeted to design, develop and implement a bi-directional energy harvester with galvanic isolation. In this work, the hardware architecture for bi-directional energy harvester rated 3.5 kW is developed with Isolated Full Bridge Boost Converter (IFBBC) as well as Dual Active Bridge (DAB) Converter configuration using modular power electronics hardware which is identical for both solar PV array and battery energy storage. In IFBBC converter, the current fed full bridge circuit is enabled and voltage fed full bridge circuit is disabled through Pulse Width Modulation (PWM) pulses for boost mode of operation and vice-versa for buck mode of operation. In DAB converter, all the switches are in active state so as to adjust the phase shift angle between primary full bridge and secondary full bridge which in turn decides the power flow directions depending on modes (boost/buck) of operation. Here, the control algorithm is developed to ensure the regulation of the common DC link voltage and maximum power extraction from the renewable energy sources depending on the selected mode (buck/boost) of operation. The circuit analysis and simulation study are conducted using PSIM 9.0 in three scenarios which are - 1.IFBBC with passive clamp, 2. IFBBC with active clamp, 3. DAB converter. In this work, a common hardware prototype for bi-directional energy harvester with 3.5 kW rating is built for IFBBC and DAB converter configurations. The power circuit is equipped with right choice of MOSFETs, gate drivers with galvanic isolation, high frequency transformer, filter capacitors, and filter boost inductor. The experiment was conducted for IFBBC converter with passive clamp under boost mode and the prototype confirmed the simulation results showing the measured efficiency as 88% at 2.5 kW output power. The digital controller hardware platform is developed using floating point microcontroller TMS320F2806x from Texas Instruments. The firmware governing the operation of the bi-directional energy harvester is written in C language and developed using code composer studio. The comprehensive analyses of the power circuit design, control strategy for battery charging/discharging under buck/boost modes and comparative performance evaluation using simulation and experimental results will be presented.

Keywords: bi-directional energy harvester, dual active bridge, isolated full bridge boost converter, intelligent green energy management system, maximum power point tracking, renewable energy sources

Procedia PDF Downloads 144

Authors: D. Bikiaris, M. Nerantzaki, I. Koliakou, A. Francone, N. Kehagias

Abstract:

In the present study, the formation of structures in poly(lactic acid) (PLA) has been investigated with respect to producing areas of regular, superficial features with dimensions comparable to those of cells or biological macromolecules. Nanoimprint lithography, a method of pattern replication in polymers, has been used for the production of features ranging from tens of micrometers, covering areas up to 1 cm², down to hundreds of nanometers. Both micro- and nano-structures were faithfully replicated. Potentially, PLA has wide uses within biomedical fields, from implantable medical devices, including screws and pins, to membrane applications, such as wound covers, and even as an injectable polymer for, for example, lipoatrophy. The possibility of fabricating structured PLA surfaces, with structures of the dimensions associated with cells or biological macro- molecules, is of interest in fields such as cellular engineering. Imprint-based technologies have demonstrated the ability to selectively imprint polymer films over large areas resulting in 3D imprints over flat, curved or pre-patterned surfaces. Here, we compare nano-patterned with nano-patterned by nanoimprint lithography (NIL) PLA film. A silicon nanostructured stamp (provided by Nanotypos company) having positive and negative protrusions was used to pattern PLA films by means of thermal NIL. The polymer film was heated from 40°C to 60°C above its Tg and embossed with a pressure of 60 bars for 3 min. The stamp and substrate were demolded at room temperature. Scanning electron microscope (SEM) images showed good replication fidelity of the replicated Si stamp. Contact-angle measurements suggested that positive microstructuring of the polymer (where features protrude from the polymer surface) produced a more hydrophilic surface than negative micro-structuring. The ability to structure the surface of the poly(lactic acid), allied to the polymer’s post-processing transparency and proven biocompatibility. Films produced in this were also shown to enhance the aligned attachment behavior and proliferation of Wharton’s Jelly Mesenchymal Stem cells, leading to the observed growth contact guidance. The bacterial attachment patterns of some bacteria, highlighted that the nano-patterned PLA structure can reduce the propensity for the bacteria to attach to the surface, with a greater bactericidal being demonstrated activity against the Staphylococcus aureus cells. These biocompatible, micro- and nanopatterned PLA surfaces could be useful for polymer– cell interaction experiments at dimensions at, or below, that of individual cells. Indeed, post-fabrication modification of the microstructured PLA surface, with materials such as collagen (which can further reduce the hydrophobicity of the surface), will extend the range of applications, possibly through the use of PLA’s inherent biodegradability. Further study is being undertaken to examine whether these structures promote cell growth on the polymer surface.

Keywords: poly(lactic acid), nano-imprint lithography, anti-bacterial properties, PLA

Procedia PDF Downloads 331

Authors: Shah Rucksana Akhter Urme

Abstract:

Agriculture is the main source of food for human consumption and feeding the world huge population, the pressure of food supply is increasing day by day. Undoubtedly, quality strain, improved plantation, farming technology, synthetic fertilizer, readily available irrigation, insecticides and harvesting technology are the main factors those to meet up the huge demand of food consumption all over the world. However, depended on this limited resources and excess amount of consuming lands, water, fertilizers leads to the end of the resources and severe climate effects has been left for our future generation. Agriculture is the most responsible to global warming, emitting more greenhouse gases than all other vehicles largely from nitrous oxide released by from fertilized fields, and carbon dioxide from the cutting of rain forests to grow crops . Farming is the thirstiest user of our precious water supplies and a major polluter, as runoff from fertilizers disrupts fragile lakes, rivers, and coastal ecosystems across the globe which accelerates the loss of biodiversity, crucial habitat and a major driver of wildlife extinction. It is needless to say that we have to more concern on how we can save the nutrients of the soil, storage of the water and avoid excessive depends on synthetic fertilizer and insecticides. In this case, eco- friendly cultivation could be a potential alternative solution to minimize effects of agriculture in our environment. The objective of this review paper is about organic cultivation following in particular biotechnological process focused on bio-fertilizer and bio-pesticides. Intense practice of chemical pesticides, insecticides has severe effect on both in human life and biodiversity. This cultivation process introduces farmer an alternative way which is nonhazardous, cost effective and ecofriendly. Organic fertilizer such as tea residue, ashes might be the best alternative to synthetic fertilizer those play important role in increasing soil nutrient and fertility. Ashes contain different essential and non-essential mineral contents that are required for plant growth. Organic pesticide such as neem spray is beneficial for crop as it is toxic for pest and insects. Recycled and composted crop wastes and animal manures, crop rotation, green manures and legumes etc. are suitable for soil fertility which is free from hazardous chemicals practice. Finally water hyacinth and algae are potential source of nutrients even alternative to soil for cultivation along with storage of water for continuous supply. Inorganic practice of agriculture, consuming fruits and vegetables becomes a threat for both human life and eco-system and synthetic fertilizer and pesticides are responsible for it. Farmers that practice eco-friendly farming have to implement steps to protect the environment, particularly by severely limiting the use of pesticides and avoiding the use of synthetic chemical fertilizers, which are necessary for organic systems to experience reduced environmental harm and health risk.

Keywords: organic farming, biopesticides, organic nutrients, water storage, global warming

Procedia PDF Downloads 61