Search results for: artificial treatment

Authors: Gihan Thilakarathna, Fernando Ishara, Rathnayake Yasith, Bandara A. M. R. Y.

Abstract:

E-learning is a crucial component of intelligent education. Even in the midst of a pandemic, E-learning is becoming increasingly important in the educational system. Several e-learning programs are accessible for students. Here, we decided to create an e-learning framework for children. We've found a few issues that teachers are having with their online classes. When there are numerous students in an online classroom, how does a teacher recognize a student's focus on academics and below-the-surface behaviors? Some kids are not paying attention in class, and others are napping. The teacher is unable to keep track of each and every student. Key challenge in e-learning is online exams. Because students can cheat easily during online exams. Hence there is need of exam proctoring is occurred. In here we propose an automated online exam cheating detection method using a web camera. The purpose of this project is to present an E-learning platform for math education and include games for kids as an alternative teaching method for math students. The game will be accessible via a web browser. The imagery in the game is drawn in a cartoonish style. This will help students learn math through games. Everything in this day and age is moving towards automation. However, automatic answer evaluation is only available for MCQ-based questions. As a result, the checker has a difficult time evaluating the theory solution. The current system requires more manpower and takes a long time to evaluate responses. It's also possible to mark two identical responses differently and receive two different grades. As a result, this application employs machine learning techniques to provide an automatic evaluation of subjective responses based on the keyword provided to the computer as student input, resulting in a fair distribution of marks. In addition, it will save time and manpower. We used deep learning, machine learning, image processing and natural language technologies to develop these research components.

Keywords: math, education games, e-learning platform, artificial intelligence

Procedia PDF Downloads 138

Authors: Jaffar Hussain, Farman Ali Shah

Abstract:

As we know that Pakistan is the developing country so it adopts new technologies for progress. In last three decays, some new technologies were introduced in the world in which Effective Microorganism was one of them. Microorganisms are one of the most power full living forces on earth. Originally, EM was developed as an odor control, farm, and animal health, human health many industrial treatments. Effective Microorganism is an organic fertilizer that contains a mixture of co-existing valuable microorganism composed from the environment. There are vast application of the EM in the world in which the researchers are explained in literature .In Pakistan work on EM technologies are under process, researcher are doing work to make them most valuable. At that time the application of EM are in agriculture, water treatment, to increase Cement strength, improving saline soil etc. Effective microorganisms are environmentally friendly , not-naturally organized, not chemically synthesized, not dangerous and not pathogenic.

Keywords: developing country, technologies, effective microorganism, researchers, Pakistan, agriculture

Procedia PDF Downloads 467

Authors: F. Slaven, M. Uys, Y. Erasmus

Abstract:

The South African National Mental Health Education Programme (SANMHEP) was a National Department of Health (NDoH) initiative to strengthen mental health services in South Africa in collaboration with the Foundation for Professional Development (FPD), SANOFI and the various provincial departments of health. The programme was implemented against the backdrop of a number of challenges in the management of mental health in the country related to staff shortages and infrastructure, the intersection of mental health with the growing burden of non-communicable diseases and various forms of violence, and challenges around substance abuse and its relationship with mental health. The Mental Health Care Act (No. 17 of 2002) prescribes that mental health should be integrated into general health services including primary, secondary and tertiary levels to improve access to services and reduce stigma associated with mental illness. In order for the provisions of the Act to become a reality, and for the journey of mental health patients through the system to improve, sufficient and skilled health care providers are critical. SANMHEP specifically targeted Medical Doctors and Professional Nurses working within the facilities that are listed to conduct 72-hour assessments, as well as District Hospitals. The aim of the programme was to improve the clinical diagnosis and management of mental disorders/conditions and the understanding of and compliance with the Mental Health Care Act and related Regulations and Guidelines in the care, treatment and rehabilitation of mental health care users. The course used a blended-learning approach and trained 1 120 health care providers through 36 workshops between February and November 2019. Of those trained, 689 (61.52%) were Professional Nurses, 337 (30.09%) were Medical Doctors, and 91 (8.13%) indicated their occupation as ‘other’ (of these more than half were psychologists). The pre- and post-evaluation of the face-to-face training sessions indicated a marked improvement in knowledge and confidence level scores (both clinical and legislative) in the care, treatment and rehabilitation of mental health care users by participants in all the training sessions. There was a marked improvement in the knowledge and confidence of participants in performing certain mental health activities (on average the ratings increased by 2.72; or 27%) and in managing certain mental health conditions (on average the ratings increased by 2.55; or 25%). The course also required that participants obtain 70% or higher in their formal assessments as part of the online component. The 337 participants who completed and passed the course scored 90% on average. This illustrates that when participants attempted and completed the course, they did very well. To further assess the effect of the course on the knowledge and behaviour of the trained mental health care practitioners a mixed-method outcome evaluation is currently underway consisting of a survey with participants three months after completion, follow-up interviews with participants, and key informant interviews with department of health officials and course facilitators. This will enable a more detailed assessment of the impact of the training on participants' perceived ability to manage and treat mental health patients.

Keywords: mental health, public health facilities, South Africa, training

Procedia PDF Downloads 104

Authors: Archana. S, Usha Rani. G, Anand Balakrishnan, Sanjana.R, Solomon F, Vijayalakshmi. J

Abstract:

Background: There is evidence that male factors contribute to the infertility of up to 50% of couples, who are evaluated and treated for infertility using advanced assisted reproductive technologies. Genetic abnormalities, including sperm chromosome aneuploidy as well as structural aberrations, are one of the major causes of male infertility. Recent advances in technology expedite the evaluation of sperm aneuploidy. The purpose of the study was to de-termine the prevalence of sperm aneuploidy in infertile males and the degree of association between DNA fragmentation and sperm aneuploidy. Methods: In this study, 75 infertile men were included, and they were divided into four abnormal groups (Oligospermia, Terato-spermia, Asthenospermia and Oligoasthenoteratospermia (OAT)). Men with children who were normozoospermia served as the control group. The Fluorescence in situ hybridization (FISH) method was used to test for sperm aneuploidy, and the Sperm Chromatin Dispersion Assay (SCDA) was used to measure the fragmentation of sperm DNA. Spearman's correla-tion coefficient was used to evaluate the relationship between sperm aneuploidy and sperm DNA fragmentation along with age. P < 0.05 was regarded as significant. Results: 75 partic-ipants' ages varied from 28 to 48 years old (35.5±5.1). The percentage of spermatozoa bear-ing X and Y was determined to be statistically significant (p-value < 0.05) and was found to be 48.92% and 51.18% of CEP X X 1 – nucish (CEP XX 1) [100] and CEP Y X 1 – nucish (CEP Y X 1) [100]. When compared to the rate of DNA fragmentation, it was discovered that infertile males had a greater frequency of sperm aneuploidy. Asthenospermia and OAT groups in sex chromosomal aneuploidy were significantly correlated (p<0.05). Conclusion: Sperm FISH and SCDA assay results showed increased sperm aneuploidy frequency, and DNA fragmentation index in infertile men compared with fertile men. There is a significant relationship observed between sperm aneuploidy and DNA fragmentation in OAT patients. When evaluating male variables and idiopathic infertility, the sperm FISH screening method can be used as a valuable diagnostic tool.

Keywords: ale infertility, dfi (dna fragmentation assay) (scd-sperm chromatin dispersion).art (artificial reproductive technology), trisomy, aneuploidy, fish (fluorescence in-situ hybridization), oat (oligoasthoteratospermia)

Procedia PDF Downloads 35

Authors: Omid Tavakol, Mahnaz Gholami

Abstract:

Introduction : In this oral presentation the main goal is discussing immediate loading in dental implants , from treatment planning and surgical guide designing to delivery , follow up and occlusal consideration . Methods and materials : first of all systematic reviews about immediate loading will be considered . besides , a comparison will be made between immediate loading and conventional loading in terms of success rate and complications . After that different methods , prosthetic options and materials best used in immediate loading will be explained. Particularly multi unit abutments and their mechanism of function will be explained .Digital impressions and designing the temporaries is the next topic we are to explicate .Next issue is the differences between single unit , multiple unit and full arch implantation in immediate loading .Following we are going to describe methods for tissue engineering and papilla formation after extraction . Last slides are about a full mouth rehabilitation via immediate loading technique from surgical designing to follow up .At the end we would talk about potential complications , how to prevent from occurrence and what to do if we face up with .

Keywords: guided surgery, digital implantology, immediate loading, digital dentistry

Procedia PDF Downloads 28

Authors: Rubia Gaur, Surindra Suthar

Abstract:

The present study investigates the anaerobic co-digestion of duckweed (Lemna gibba) and waste activated sludge (WAS) of different proportions with acclimatized anaerobic granular sludge (AAGS) as inoculum in mesophilic conditions. Batch experiments were performed in 500 mL capacity reagent bottles at 300C temperature. Varied combinations of pre-treated duckweed biomass with constant volume of anaerobic inoculum (AAGS - 100 mL) and waste activated sludge (WAS - 22.5 mL) were devised into five batch tests. The highest methane generation was observed with batch study, T4. The Gompertz model fits well on the experimental data of the batch study, T4. The values of correlation coefficient were achieved relatively higher (R2 ≥ 0.99). The co-digestion without pre-treatment of both duckweed and WAS shows poor generation of methane gas.

Keywords: aquatic weed, biogas, biomass, Gompertz equation, waste activated sludge

Procedia PDF Downloads 274

Authors: Jose Manuel Rodriguez-Dominguez, Rodrigo Barba-Gonzalez, Ernesto Tapia-Campos

Abstract:

Sprekelia formosissima (L.) Herbert is a bulbous ornamental species of the monocotyledonous Amaryllidaceae family, and it is a perennial, herbaceous monotypic plant commonly known as ‘Aztec Lily’ or ‘Jacobean Lily’; it is distributed through Mexico and Guatemala. Its scarlet flowers with curved petals have made it an exceptional ornamental pot plant. Cytogenetic studies in this species have shown differences in chromosome number (2n=60, 120, 150, 180) with a basic number x=30. Different reports have shown a variable ploidy level (diploid, tetraploid, pentaploid and hexaploid); however, triploid plants have not been reported. In this work, triploid plants of S. formosissima were obtained by crossing tetraploid (2n=4x=120) with diploid (2n=2x=60) genotypes of this species; the seeds obtained from the crosses were placed in pots with a moist substrate made of Peat Moss: Vermiculite (7:3) for germination. Root tips were collected, and metaphasic chromosome preparations were performed. For chromosome counting, the best five metaphases obtained were photographed with a Leica DMRA2 microscope (Leica Microsystems, Germany) microscopy coupled to an Evolution QEI camera under phase contrast (Media-Cybernetics). Chromosomes counting in root-tip cells showed that 100% of the plants were triploid (2n=3x=90). Although tetraploid or pentaploid plants of S. formosissima are highly appreciated, they usually have lower growth rates than related diploid ones. For this reason, it is important to obtain triploid plants, which have advantages such as higher growth rates than tetraploid and pentaploid, larger flowers than those of the diploid plants and they are expected to not be able to produce seeds because their gametes are aneuploids. Furthermore, triploids may become very important for genomic research in the future, creating opportunities for discovering and monitoring genomic and transcriptomic changes in unbalanced genomes, hence the importance of this work.

Keywords: Amaryllidaceae, cytogenetics, ornamental, ploidy level

Procedia PDF Downloads 181

Authors: Eun Jung Sohn, Hwan Tae Park

Abstract:

Autophagy is a cellular response to stress or environment on cell survival. Here, we investigated the role of ectopic expression of miR 200c-3p in autophagy. Ectopic expression of miR 200c-3p increased the expression of IRE1alpha, ATF6 and CHOP by western blot and RT-qPCR. Furthermore, the level of microRNA 200c-3p was enhanced by treatment of TG or overexpression of GRP 78. Also, ectopic expression of miR200c-3p increased the LC3 II expression by western blot and RT-qPCR. Also, we found that western blot assay showed that miR200c-3p inhibitor was blocked the starvation–induced LC3II levels. Furthermore, starvation stress increased the level of miR200c-3p in different kinetics. Ectopic expression of miR200c-3p attenuated LC3II expression in IRE1 siRNA transfected PC3 cells. Here, we first demonstrate that miR200c-3p regulates autophagy via ER stress pathway.

Keywords: Autophagy, ER stress, LC3II, miR200c-3p

Procedia PDF Downloads 274

Authors: Mohammad Ruhul Amin, Nusrat Jahan

Abstract:

Natural gas is a cleaner fuel compared to the others. But it needs some treatment before it is in a state to be used. So natural gas purification is an integral part of any process where natural gas is used as raw material or fuel. There are several impurities in natural gas that have to be removed before use. CO2 is one of the major contaminants. In this project we have removed CO2 by amine process by using MEA solution. We have built up the whole amine process for removing CO2 in Aspen Hysys and simulated the process. At the end of simulation we have got very satisfactory results by using MEA solution for the removal of CO2. Simulation result shows that amine absorption process enables to reduce CO2 content from NG by 58%. HYSYS optimizer allowed us to get a perfect optimized plant. After optimization the profit of existing plant is increased by 2.34 %.Simulation and optimization by Aspen-HYSYS simulator makes available us to enormous information which will help us to further research in future.

Keywords: Aspen–Hysys, CO2 removal, flowsheet development, MEA solution, natural gas optimization

Procedia PDF Downloads 480

Authors: Gary Pattemore, Michael Edgar, Andrew Job, Marina Auad, Kathryn Job

Abstract:

As critical commodities become more scarce, significant time and resources have been used to better understand complicated ore bodies and extract their full potential. These challenging ore bodies provide several pain points for geologists and engineers to overcome, poor handling of these issues flows downs stream to the processing plant affecting throughput rates and recovery. Many open cut mines utilise blast hole drilling to extract additional information to feed back into the modelling process. This method requires samples to be collected during or after blast hole drilling. Samples are then sent for assay with turnaround times varying from 1 to 12 days. This method is time consuming, costly, requires human exposure on the bench and collects elemental data only. To address this challenge, research has been undertaken to utilise hyperspectral imaging across a broad spectrum to scan samples, collars or take down hole measurements for minerals and moisture content and grade abundances. Automation of this process using unmanned vehicles and on-board processing reduces human in pit exposure to ensure ongoing safety. On-board processing allows data to be integrated into modelling workflows with immediacy. The preliminary results demonstrate numerous direct and indirect benefits from this new technology, including rapid and accurate grade estimates, moisture content and mineralogy. These benefits allow for faster geo modelling updates, better informed mine scheduling and improved downstream blending and processing practices. The paper presents recommendations for implementation of the technology in open cut mining environments.

Keywords: grade control, hyperspectral scanning, artificial intelligence, autonomous mining, machine learning

Procedia PDF Downloads 94

Authors: Mahdi Farajzadeh Ajirlou

Abstract:

Prior evidence of normal cardiac anatomy is desirable to relieve the anxiety of cases with a family history of congenital heart disease or to offer the option of early gestation termination or close follow-up should a cardiac anomaly be proved. Fetal heart discovery plays an important part in the opinion of the fetus, and it can reflect the fetal heart function of the fetus, which is regulated by the central nervous system. Acquisition of ventricular volume and inflow data would be useful to quantify more valve regurgitation and ventricular function to determine the degree of cardiovascular concession in fetal conditions at threat for hydrops fetalis. This study discusses imaging the fetal heart with transvaginal ultrasound, Doppler ultrasound, three-dimensional ultrasound (3DUS) and four-dimensional (4D) ultrasound, spatiotemporal image correlation (STIC), glamorous resonance imaging and cardiac catheterization. Doppler ultrasound (DUS) image is a kind of real- time image with a better imaging effect on blood vessels and soft tissues. DUS imaging can observe the shape of the fetus, but it cannot show whether the fetus is hypoxic or distressed. Spatiotemporal image correlation (STIC) enables the acquisition of a volume of data concomitant with the beating heart. The automated volume accession is made possible by the array in the transducer performing a slow single reach, recording a single 3D data set conforming to numerous 2D frames one behind the other. The volume accession can be done in a stationary 3D, either online 4D (direct volume scan, live 3D ultrasound or a so-called 4D (3D/ 4D)), or either spatiotemporal image correlation-STIC (off-line 4D, which is a circular volume check-up). Fetal cardiovascular MRI would appear to be an ideal approach to the noninvasive disquisition of the impact of abnormal cardiovascular hemodynamics on antenatal brain growth and development. Still, there are practical limitations to the use of conventional MRI for fetal cardiovascular assessment, including the small size and high heart rate of the mortal fetus, the lack of conventional cardiac gating styles to attend data accession, and the implicit corruption of MRI data due to motherly respiration and unpredictable fetal movements. Fetal cardiac MRI has the implicit to complement ultrasound in detecting cardiovascular deformations and extracardiac lesions. Fetal cardiac intervention (FCI), minimally invasive catheter interventions, is a new and evolving fashion that allows for in-utero treatment of a subset of severe forms of congenital heart deficiency. In special cases, it may be possible to modify the natural history of congenital heart disorders. It's entirely possible that future generations will ‘repair’ congenital heart deficiency in utero using nanotechnologies or remote computer-guided micro-robots that work in the cellular layer.

Keywords: fetal, cardiac MRI, ultrasound, 3D, 4D, heart disease, invasive, noninvasive, catheter

Procedia PDF Downloads 16

Authors: Nader Al-Rashidi, David Greenhalgh

Abstract:

Mathematical modelling techniques are now being used by health organizations worldwide to help understand the likely impact that intervention strategies treatment options and combinations of these have on the prevalence and incidence of hepatitis C virus (HCV) in the people who inject drugs (PWID) population. In this poster, we develop a deterministic, compartmental mathematical model to approximate the spread of the HCV in a PWID population that has been divided into two groups by time since onset of injection. The model assumes that after injection needles adopt the most infectious state of their previous state or that of the PWID who last injected with them. Using analytical techniques, we find that the model behaviour is determined by the basic reproductive number R₀, where R₀ = 1 is a critical threshold separating two different outcomes. The disease-free equilibrium is globally stable if R₀ ≤ 1 and unstable if R₀ > 1. Additionally, we make some simulations where have confirmed that the model tends to this endemic equilibrium value with realistic parameter values giving an HCV prevalence.

Keywords: hepatitis C, people who inject drugs, HCV, PWID

Procedia PDF Downloads 134

Authors: Shadi Fathi, Moura Mehravar, Mujib Rahman

Abstract:

The railwaytransportation network in the UK is over 100 years old and is known as one of the oldest mass transit systems in the world. This aged track network requires frequent closure for maintenance. One of the main reasons for closure is inadequate drainage due to the leakage in the buried drainage pipes. The leaking water can cause localised subgrade weakness, which subsequently can lead to major ground/substructure failure.Different condition assessment methods are available to assess the railway substructure. However, the existing condition assessment methods are not able to detect any local ground weakness/damageand provide details of the damage (e.g. size and location). To tackle this issue, a hybrid back-analysis technique based on artificial neural network (ANN) and genetic algorithm (GA) has been developed to predict the substructurelayers’ moduli and identify any soil weaknesses. At first, afinite element (FE) model of a railway track section under Falling Weight Deflection (FWD) testing was developed and validated against field trial. Then a drainage pipe and various scenarios of the local defect/ soil weakness around the buried pipe with various geometriesand physical properties were modelled. The impact of the soil local weaknesson the track surface deflection wasalso studied. The FE simulations results were used to generate a database for ANN training, and then a GA wasemployed as an optimisation tool to optimise and back-calculate layers’ moduli and soil weakness moduli (ANN’s input). The hybrid ANN-GA back-analysis technique is a computationally efficient method with no dependency on seed modulus values. The modelcan estimate substructures’ layer moduli and the presence of any localised foundation weakness.

Keywords: finite element (FE) model, drainage defect, falling weight deflectometer (FWD), hybrid ANN-GA

Procedia PDF Downloads 139

Authors: Belinda Crissman

Abstract:

Serious mental disorder is greatly overrepresented in prisoners compared to the general community, with consequences for prison management, recidivism and the prisoners themselves. Incarcerated individuals with psychotic disorders experience insufficient detection and treatment and higher rates of suicide in custody. However direct evidence to explain the overrepresentation of individuals with psychosis in prisons is sparse. The current study aimed to use a life course criminology perspective to answer two key questions: 1) What is the temporal relationship between psychosis and offending (does first mental health contact precede first recorded offence, or does the offending precede the mental health diagnosis)? 2) Are there key temporal points or system contacts prior to incarceration that could be identified as opportunities for early intervention? Data from the innovative Queensland Linkage project was used to link individuals with their corrections, health and relevant social service systems to answer these questions.

Keywords: mental disorder, crime, life course criminology, prevention

Procedia PDF Downloads 119

Authors: Surapong Vongvatcharanon, Fardeela Binalee, Wandee Udomuksorn, Ekkasit Kumarnsit, Uraporn Vongvatcharanon

Abstract:

Hypogonadism is characterized by a decline in sex hormone levels, especially testosterone. It has been shown to be an important contributor to the decrease in muscle mass, muscle strength and performance, a condition known as sarcopenia. Preparations from Butea superba Roxb. (red Kwao Krua) have been reported to have androgenic properties. The active compounds are proposed to be flavonoids and flavonoid glycosides. Treatment with B. superba has been shown to improve erectile dysfunction in males. Parvalbumin (PV) is a relaxing factor and identified in fast twitch fibers. Alterations of the PV levels affects skeletal muscle functions. This study aimed to investigate the effects of orhchidectomy, testosterone replacement and different doses of Butea superba Roxb. on the structure, performance, levels of parvalbumin, parvalbumin and androgen receptor immunoreactivities in the extensor digitorum longus (EDL) and gastrocnemius muscles of orchidectomized rats. Twelve-week old male Wistar rats were randomly divided into 6 groups; sham-operated (SHAM), orchidectomized (BS-0), orchidectomized group that was treated with testosterone replacement of 6 µg/kg (TP) or an orchidectomized group that was treated with various doses of an extract from Butea superba Roxb.; 5 mg/kg (BS-5), 50 mg/kg (BS-50) and 500 mg/kg (BS-500) all for 90 days. The testosterone level, epididymis, seminal vesicle, prostate gland, vas deference weight, muscle fiber size, strength and endurance in both the EDL and gastrocnemius muscle were decreased in the BS-0 group but increased in the testosterone replacement group. Treatment with the B. superba Roxb. extract replacement group improved muscle fiber size, strength and endurance, but not total testosterone levels, or the epididymis, seminal vesicle, prostate gland, vas deference weight. Furthermore, the parvalbumin level, parvalbumin and androgen receptor immunoreactivities were reduced in the BS-0 group but increased in the testosterone replacement group and the B. superba Roxb. extract groups for both the EDL and gastrocnemius muscle. This study indicated that the reduction of testosterone level led to a decrease of the androgen receptor density resulting in a decline in the muscle mass and parvalbumin levels. The decrease of parvalbumin levels affected muscle performance. Testosterone replacement increased the androgen receptor density and led to an increase of muscle mass and parvalbumin levels. The increase in the parvalbumin levels may result in an improvement of muscle performance. This may explain one mechanism of testosterone on muscle mass and strength in the testosterone dependent sarcopenia. The B. superba Roxb. extract groups also had improved muscle mass, strength and endurance, parvalbumin level, parvalbumin and androgen immunoreactivities compared to the BS-O group . Butea superba Roxb. Extracts contains a flavonoid (3, 7, 3'-Trihydroxy-4'-methoxyflavone), flavonoiglycoside (3, 3'-dihydroxy-4'-methoxyflavone-7-O-β-D-glucopyranoside) and isoflavanolignans (butesuperins A and butesuperins B) all known to inhibit the cAMP phosphodiesterase enzyme. Therefore, cAMP signaling may have adaptive effects on skeletal muscle by increasing muscle mass, strength and endurance.

Keywords: Butea superba, parvalbumin, skeletal muscle, orchidectomy

Procedia PDF Downloads 406

Authors: Aakanchha Jain, D. V. Kohli

Abstract:

Cubosomes are nanoparticles but instead of the solid particles, cubosomes are self-assembled liquid crystalline particles of certain surfactant with proper ratio of water with a microstructure that provides unique properties of practical interest. Cubosomes encapsulating Fluconazole were prepared by emulsification method and characterized for particle size, entrapment efficiency. The cubosomes prepared were 257.2±2.94 nm in size with drug entrapment efficiency of 66.2±2.69%. The optimized formulation characterized for shape and surface morphology by TEM and SEM analysis. SEM photograph showed the smooth surface of optimized cubosomes and TEM photograph revealed square somewhat circular intact shapes of cubosomes. MIC was determined by XTT based method and antifungal activity was determined in vitro. The cumulative percentage of Fnz from cubosomes permeated via dialysis membrane (MWCO 12-14 KD) showed a percent cumulative drug release of 76.86% while Fnz solution showed release up to 91.04% in 24 hours in PBS (pH 6.5)(p < 0.005).

Keywords: Candids albicans, cubosomes, fluconazole, topical delivery

Procedia PDF Downloads 287

Authors: Xiao-Jing Zhu, Liang Zhou, Shi-Zhong Zheng

Abstract:

Various studies have shown that diallyl trisulfide (DATS) can protect the liver injury, and DATS has a strong antioxidant property. The aim of this study is to evaluate the in vivo role of DATS in protecting the liver against injury and fibrogenesis and further explores the underlying mechanisms. Our results demonstrated that DATS protected the liver from CCl4-caused injury by suppressing the elevation of ALT and AST activities, and by improving the histological architecture of the liver. Treatment with DATS or colchicine improved the liver fibrosis by sirius red staining and immunofluorescence. In addition, immunohistochemistry, western blot, and RT-PCR analyses indicated that DATS inhibited HSC activation. Furthermore, DATS attenuated oxidative stress by increasing glutathione and reducing lipid peroxides and malondialdehyde. These findings suggest that the protective effect of DATS on CCl4-caused liver injury and liver fibrogenesis was, at least partially, attributed to its antioxidant activity.

Keywords: liver fibrogenesis, liver injury, oxidative stress, DATS

Procedia PDF Downloads 413

Authors: A. Askerov, Y. Teterin, P. Yartcev, S. Novikov

Abstract:

Introduction: Acute pancreatitis (AP) is a socially significant problem for public health and continues to be one of the most common causes of hospitalization of patients with pathology of the gastrointestinal tract. It is characterized by high mortality rates, which reaches 62-65% in infected pancreatic necrosis. Aims & Methods: The study group included 63 patients who underwent transluminal drainage (TLD) fluid collection (FC). All patients were performed transabdominal ultrasound, computer tomography of the abdominal cavity and retroperitoneal organs and endoscopic ultrasound (EUS) of the pancreatobiliary zone. The EUS was used as a final diagnostic method to determine the characteristics of FC. The indications for TLD were: the distance between the wall of the hollow organ and the FC was not more than 1 cm, the absence of large vessels on the puncture trajectory (more than 3 mm), and the size of the formation was more than 5 cm. When a homogeneous cavity with clear, even contours was detected, a plastic stent with rounded ends (“double pig tail”) was installed. The indication for the installation of a fully covered self-expanding stent was the detection of nonhomogeneous anechoic FC with hyperechoic inclusions and cloudy purulent contents. In patients with necrotic forms after drainage of the purulent cavity, a cystonasal drainage with a diameter of 7Fr was installed in its lumen under X-ray control to sanitize the cavity with a 0.05% aqueous solution of chlorhexidine. Endoscopic necrectomy was performed every 24-48 hours. The plastic stent was removed in 6 month, the fully covered self-expanding stent - in 1 month after the patient was discharged from the hospital. Results: Endoscopic TLD was performed in 63 patients. The FC corresponding to interstitial edematous pancreatitis was detected in 39 (62%) patients who underwent TLD with the installation of a plastic stent with rounded ends. In 24 (38%) patients with necrotic forms of FC, a fully covered self-expanding stent was placed. Communication with the ductal system of the pancreas was found in 5 (7.9%) patients. They underwent pancreaticoduodenal stenting. A complicated postoperative period was noted in 4 (6.3%) cases and was manifested by bleeding from the zone of pancreatogenic destruction. In 2 (3.1%) cases, this required angiography and endovascular embolization a. gastroduodenalis, in 1 (1.6%) case, endoscopic hemostasis was performed by filling the cavity with 4 ml of Hemoblock hemostatic solution. The combination of both methods was used in 1 (1.6%) patient. There was no evidence of recurrent bleeding in these patients. Lethal outcome occurred in 4 patients (6.3%). In 3 (4.7%) patients, the cause of death was multiple organ failure, in 1 (1.6%) - severe nosocomial pneumonia that developed on the 32nd day after drainage. Conclusions: 1. EUS is not only the most important method for diagnosing FC in AP, but also allows you to determine further tactics for their intraluminal drainage.2. Endoscopic intraluminal drainage of fluid zones in 45.8% of cases is the final minimally invasive method of surgical treatment of large-focal pancreatic necrosis. Disclosure: Nothing to disclose.

Keywords: acute pancreatitis, fluid collection, endoscopy surgery, necrectomy, transluminal drainage

Procedia PDF Downloads 91

Authors: Jack Nash, Chris Simpson, Holly Hurn, Ronel Terblanche, Alan Mistlin

Abstract:

There is an increasing incidence of mild traumatic brain injury (mTBI) cases throughout sport and with this, a growing interest from governing bodies to ensure these are managed appropriately and player welfare is prioritised. The Berlin consensus statement on concussion in sport recommends a multidisciplinary approach when managing those patients who do not have full resolution of mTBI symptoms. There are as of yet no standardised guideline to follow in the treatment of complex cases mTBI in athletes. The aim of this project was to analyse the outcomes, both clinical and vocational, of all patients admitted to the mild Traumatic Brain Injury (mTBI) service at the UK’s Defence Military Rehabilitation Centre Headley Court between 1st June 2008 and 1st February 2017, as a result of a sport induced injury, and evaluate potential predictive indicators of outcome. Patients were identified from a database maintained by the mTBI service. Clinical and occupational outcomes were ascertained from medical and occupational employment records, recorded prospectively, at time of discharge from the mTBI service. Outcomes were graded based on the vocational independence scale (VIS) and clinical documentation at discharge. Predictive indicators including referral time, age at time of injury, previous mental health diagnosis and a financial claim in place at time of entry to service were assessed using logistic regression. 45 Patients were treated for sport-related mTBI during this time frame. Clinically 96% of patients had full resolution of their mTBI symptoms after input from the mTBI service. 51% of patients returned to work at their previous vocational level, 4% had ongoing mTBI symptoms, 22% had ongoing physical rehabilitation needs, 11% required mental health input and 11% required further vestibular rehabilitation. Neither age, time to referral, pre-existing mental health condition nor compensation seeking had a significant impact on either vocational or clinical outcome in this population. The vast majority of patients reviewed in the mTBI clinic had persistent symptoms which could not be managed in primary care. A consultant-led, multidisciplinary approach to the diagnosis and management of mTBI has resulted in excellent clinical outcomes in these complex cases. High levels of symptom resolution suggest that this referral and treatment pathway is successful and is a model which could be replicated in other organisations with consultant led input. Further understanding of both predictive and individual factors would allow clinicians to focus treatments on those who are most likely to develop long-term complications following mTBI. A consultant-led, multidisciplinary service ensures a large number of patients will have complete resolution of mTBI symptoms after sport-related mTBI. Further research is now required to ascertain the key predictive indicators of outcome following sport-related mTBI.

Keywords: brain injury, concussion, neurology, rehabilitation, sports injury

Procedia PDF Downloads 139

Authors: R. P. Hewawasam, A. F. Dulhunty

Abstract:

The ryanodine receptor (RyR) is an intracellular ion channel that releases Ca2+ from the sarcoplasmic reticulum and is essential for the excitation-contraction coupling and contraction in striated muscle. Human muscle specific glutathione transferase M2-2 (GSTM2-2) is a highly specific inhibitor of cardiac ryanodine receptor (RyR2) activity. Single channel-lipid bilayer studies and Ca2+ release assays performed using the C-terminal half of the GSTM2-2 and its mutants F157A and Y160A confirmed the ability of the C terminal domain of GSTM2-2 to specifically inhibit the cardiac ryanodine receptor activity. Objective of the present study is to determine the effect of C terminal domain of GSTM2-2 (GSTM2-2C) and the mutants, F157A and Y160A on the Ca2+ transients of neonatal ventricular cardiomyocytes. Primary cardiomyocytes were cultured from neonatal rats. They were treated with GSTM2-2C and the two mutants F157A and Y160A at 15µM and incubated for 2 hours. Then the cells were led with Fluo-4AM, fluorescent Ca2+ indicator, and the field stimulated (1 Hz, 3V and 2ms) cells were excited using the 488 nm argon laser. Contractility of the cells were measured and the Ca2+ transients in the stained cells were imaged using Leica SP5 confocal microscope. Peak amplitude of the Ca2+ transient, rise time and decay time from the peak were measured for each transient. In contrast to GSTM2C which significantly reduced the % shortening (42.8%) in the field stimulated cells, F157A and Y160A failed to reduce the % shortening.Analysis revealed that the average amplitude of the Ca2+ transient was significantly reduced (P<0.001) in cells treated with the wild type GSTM2-2C compared to that of untreated cells. Cells treated with the mutants F157A and Y160A didn’t change the Ca2+ transient significantly compared to the control. A significant increase in the rise time (P< 0.001) and a significant reduction in the decay time (P< 0.001) were observed in cardiomyocytes treated with GSTM2-2C compared to the control but not with F157A and Y160A. These results are consistent with the observation that GSTM2-2C reduced the Ca2+ release from the cardiac SR significantly whereas the mutants, F157A and Y160A didn’t show any effect compared to the control. GSTM2-2C has an isoform-specific effect on the cardiac ryanodine receptor activity and also it inhibits RyR2 channel activity only during diastole. Selective inhibition of RyR2 by GSTM2-2C has significant clinical potential in the treatment of cardiac arrhythmias and heart failure. Since GSTM2-2C-terminal construct has no GST enzyme activity, its introduction to the cardiomyocyte would not exert any unwanted side effects that may alter its enzymatic action. The present study further confirms that GSTM2-2C is capable of decreasing the Ca2+ release from the cardiac SR during diastole. These results raise the future possibility of using GSTM2-2C as a template for therapeutics that can depress RyR2 function when the channel is hyperactive in cardiac arrhythmias and heart failure.

Keywords: arrhythmia, cardiac muscle, cardiac ryanodine receptor, GSTM2-2

Procedia PDF Downloads 271

Authors: Michael J. Kristiono

Abstract:

This paper attempts to investigate the reasons behind the negative sentiments directed towards Chinese Indonesians from International Relations (IR) perspective. By tracing back the treatment of the New Order government towards ethnic Chinese, it was found that such demonization initially happened due to two politically motivated reasons. Firstly, as part of de-Soekarnoization done by the New Order, the Chinese were outcast because Chinese identity does not conform to the 'Indonesian identity', which was in essence, the Javanese identity. Secondly, the condition reflected the change in Indonesian foreign policy which drifted apart from People’s Republic of China (PRC) as the latter was suspected to be involved in September 30 Movement. Then, this paper argues that due to those reasons, coupled by blatant maltreatment from the New Order Government, Chinese Indonesians were constructed as the Others, that is, as non-Indonesians. Such construct has been deeply embedded such that reconciliation attempts done by the Reformation Era government were not sufficient enough to stop ethnic discrimination towards Chinese Indonesians from happening even until the present.

Keywords: Chinese Indonesians, ethnic discrimination, identity, New Order

Procedia PDF Downloads 319

Authors: Andrey A. Tyuftin, Rachael Reid, Paula Bourke, Patrick J. Cullen, Seamus Fanning, Paul Whyte, Declan Bolton , Joe P. Kerry

Abstract:

One of the primary spoilage issues associated with vacuum-packed beef products is blown pack spoilage (BPS) caused by the psychrophilic spore-forming strain of Clostridium spp. Spores derived from this organism can be activated after heat-shrinking (eg. 90°C for 3 seconds). To date, research into the control of Clostridium spp in beef packaging is limited. Active packaging in the form of antimicrobially-active coatings may be one approach to its control. Antimicrobial compounds may be incorporated into packaging films or coated onto the internal surfaces of packaging films using a carrier matrix. Three naturally-sourced, commercially-available antimicrobials, namely; Auranta FV (AFV) (bitter oranges extract) from Envirotech Innovative Products Ltd, Ireland; Inbac-MDA (IMDA) from Chemital LLC, Spain, mixture of different organic acids and sodium octanoate (SO) from Sigma-Aldrich, UK, were added into gelatin solutions at 2 concentrations: 2.5 and 3.5 times their minimum inhibition concentration (MIC) against Clostridium estertheticum (DSMZ 8809). These gelatin solutions were coated onto the internal polyethylene layer of cold plasma treated, heat-shrinkable laminates conventionally used for meat packaging applications. Atmospheric plasma was used in order to enhance adhesion between packaging films and gelatin coatings. Pouches were formed from these coated packaging materials, and beef cuts which had been inoculated with C. estertheticum were vacuum packaged. Inoculated beef was vacuum packaged without employing active films and this treatment served as the control. All pouches were heat-sealed and then heat-shrunk at 90°C for 3 seconds and incubated at 2°C for 100 days. During this storage period, packs were monitored for the indicators of blown pack spoilage as follows; gas bubbles in drip, loss of vacuum (onset of BPS), blown, the presence of sufficient gas inside the packs to produce pack distension and tightly stretched, “overblown” packs/ packs leaking. Following storage and assessment of indicator date, it was concluded that AFV- and SO-containing packaging inhibited the growth of C. estertheticum, significantly delaying the blown pack spoilage of beef primals. IMDA did not inhibit the growth of C. estertheticum. This may be attributed to differences in release rates and possible reactions with gelatin. Overall, active films were successfully produced following plasma surface treatment, and experimental data demonstrated clearly that the use of antimicrobially-active films could significantly prolong the storage stability of beef primals through the effective control of BPS.

Keywords: active packaging, blown pack spoilage, Clostridium, antimicrobials, edible coatings, food packaging, gelatin films, meat science

Procedia PDF Downloads 251

Authors: S. Mohammadzadehmoghadam, Y. Dong

Abstract:

In this study, Bombyx mori silk fibroin/gelatin (SF/GT) nanocomposite with different GT ratio (SF/GT 100/0, 90/10 and 70/30) were prepared by electrospinning process and crosslinked with glutaraldehyde (GA) vapor. Properties of crosslinked SF/GT nanocomposites were investigated by scanning electron microscopy (SEM), mechanical test, water uptake capacity (WUC) and porosity. From SEM images, it was found that fiber diameter increased as GT content increased. The results of mechanical test indicated that the SF/GT 70/30 nanocomposites had both the highest Young’s modulus of 342 MPa and the highest tensile strength of about 14 MPa. However, porosity and WUC decreased from 62% and 405% for pristine SF to 47% and 232% for SF/GT 70/30, respectively. This behavior can be related to higher degree of crosslinking as GT ratio increased which altered the structure and physical properties of scaffolds. This study showed that incorporation of GT into SF nanofibers can enhance mechanical properties of resultant nanocomposite, but the GA treatment should be optimized to control and fine-tune other properties to warrant their biomedical application.

Keywords: electrospinning, gelatin, silk fibroin, mechanical properties, nanocomposites

Procedia PDF Downloads 138

Authors: Stefan Nicolae, Cristina Cirtoaje, Emil Petrescu, Florin-Razvan Duca

Abstract:

In the context of the accelerated expansion of urban agglomerations and the exponential development of industry, a huge amount of water is used, and a crisis of drinking water may occur any time. Classic wastewater treatment removes most pollutants but, for some chemical residues, special methods are needed. Carbon nanotubes and other carbon materials might be used in many cases [1-2], especially for heavy metals removal but also on pharmaceutical products such as paracetamol [3]. Our research has confirmed the better efficiency of nanotubes compared to graphene on paracetamol removal from water, but even better results were obtained on single-walled nanotubes (SWCNTs) and graphene nanoplatelets. This can be due to their better dispersion in water which leads to an increased contact surface, so we propose a filtration system of membranes and carbon materials that can be used for paracetamol removal from wastewater but also for other drugs that affect the aquatic life as well as terrestrial animals and people who use this contaminated water.

Keywords: applied physics, wastewater, nanomaterials, enviromental science

Procedia PDF Downloads 175

Authors: Rozh Abdulrahman Kareem

Abstract:

The displacement of individuals has become a common interest for international players. Mostly occurs in Islamic states, as religion is considered the most common cause of this form of displacement. Therefore, this thesis aims to depict the reality of the situations of the refugees, particularly in KRI, illustrating how they are treated and protected and if the treatment merits the protection clause as envisaged in the 1951 Refugee Convention. Overall, the aim is to touch on the issue of protection by non-governmental organizations and government towards the refugees here. In light of this, it focused on the adequate protection of refugees in relation to the refugee law. In the Middle East, including Iraq, there have been multiple reports on violations of these refugee laws and human rights. Protection involves providing physical security to the concerned parties, functional administration with legal structures, and infrastructural setup that could help citizens exercise rights. The KRI has provided the refugees with various benefits, including education, access to residency, and employment. It also provided transitionary in various social dimensions like gender-based violence. The Convention on Status of Refugees 1951 tried to resolve this problem, whereby the principle of ‘nonrefoulement’ under Article 33 was passed. The ‘nonrefoulement’, an exceptional reference, was enacted to protect refugees from forcible return to their countries of the original. However, the convention never addressed an unusual scenario regarding the application of this principle, ‘Extradition Treaties.’ Even though some scholarly article exists regarding the problems of refugees, the topic of interplay between Nonrefoulement and Extradition Treaties has never been explained in detail in the available books on refugee laws and practices. Each year, millions of refugees seek protection from foreign countries for fear of being tortured, victimized, or executed. People seeking international protection are susceptible and insecure. The main objective of the prevention is to provide security to citizens susceptible to inhuman treatment, distress, oppression, or other human rights defilements when they arrive back in their own countries. The refugee situation may get worse in the near future. Just like several nations within the Middle East, Iraq is not a signatory to the globally acknowledged legal structure for the protection of refugees. The first law of 1971 in Iraq was issued only for military or political causes. This law also establishes benefits such as the right to education and health services and the right to acquire employment just as the Iraqi nationals. The other legislative instrument is the 21st law from the ministry of migration of Iraq widened the description of an immigrant to incorporate the definition from the refugee resolution. Nonetheless, there is a lack of overall consistency in the protection provided under these legislations regarding rights and entitlement. A Memorandum of Understanding was signed in October 2016 by the UNHCR and the Iraq government to develop the protection of refugees. Under the term of this MoU, the Iraqi Government is obligated to provide identity documents to asylum seekers beside that UNHCR provides more guidance.

Keywords: law, refugee, protection, Kurdistan

Procedia PDF Downloads 53

Authors: Harihara Prakash Ramanathan, Daksha Mishra, Ankita Dhaduk

Abstract:

Relevance: This qualitative study will educate the clinician in putting into practice the advanced method of movement science in restoring the function. Purpose: The purpose of this study is to compare the effectiveness of Active Release Technique and myofascial release technique on range of motion, neck function and pain in patients with upper trapezius spasm. Methods/Analysis: The study was approved by the institutional Human Research and Ethics committee. This study included sixty patients of age group between 20 to 55 years with upper trapezius spasm. Patients were randomly divided into two groups receiving Active Release Technique (Group A) and Myofascial Release Technique (Group B). The patients were treated for 1 week and three outcome measures ROM, pain and functional level were measured using Goniometer, Visual analog scale(VAS), Neck disability Index Questionnaire(NDI) respectively. Paired Sample 't' test was used to compare the differences of pre and post intervention values of Cervical Range of motion, Neck disability Index, Visual analog scale of Group A and Group B. Independent't' test was used to compare the differences between two groups in terms of improvement in cervical range of motion, decrease in visual analogue scale(VAS), decrease in Neck disability index score. Results: Both the groups showed statistically significant improvements in cervical ROM, reduction in pain and in NDI scores. However, mean change in Cervical flexion, cervical extension, right side flexion, left side flexion, right side rotation, left side rotation, pain, neck disability level showed statistically significant improvement (P < 0. 05)) in the patients who received Active Release Technique as compared to Myofascial release technique. Discussion and conclusions: In present study, the average improvement immediately post intervention is significantly greater as compared to before treatment but there is even more improvement after seven sessions as compared to single session. Hence, this proves that several sessions of Manual techniques are necessary to produce clinically relevant results. Active release technique help to reduce the pain threshold by removing adhesion and promote normal tissue extensibility. The act of tensioning and compressing the affected tissue both with digital contact and through the active movement performed by the patient can be a plausible mechanism for tissue healing in this study. This study concluded that both Active Release Technique (ART) and Myofascial release technique (MFR) are equally effective in managing upper trapezius muscle spasm, but more improvement can be achieved by Active Release Technique (ART). Impact and Implications: Active Release Technique can be adopted as mainstay of treatment approach in treating trapezius spasm for faster relief and improving the functional status.

Keywords: trapezius spasm, myofascial release, active release technique, pain

Procedia PDF Downloads 257

Authors: Audrey Ngambia, Ondrej Masek, Valentina Erastova

Abstract:

Biochar is an amorphous carbon-rich material generated from the pyrolysis of biomass with multifarious properties and functionality. Biochar has shown proven applications in the treatment of flue gas and organic and inorganic pollutants in soil and water/wastewater as a result of its multiple surface functional groups and porous structures. These properties have also shown potential in energy storage and carbon capture. The availability of diverse sources of biomass to produce biochar has increased interest in it as a sustainable and environmentally friendly material. The properties and porous structures of biochar vary depending on the type of biomass and high heat treatment temperature (HHT). Biochars produced at HHT between 400°C – 800°C generally have lower H/C and O/C ratios, higher porosities, larger pore sizes and higher surface areas with temperature. While all is known experimentally, there is little knowledge on the porous role structure and functional groups play on processes occurring at the atomistic scale, which are extremely important for the optimization of biochar for application, especially in the adsorption of gases. Atomistic simulations methods have shown the potential to generate such amorphous materials; however, most of the models available are composed of only carbon atoms or graphitic sheets, which are very dense or with simple slit pores, all of which ignore the important role of heteroatoms such as O, N, S and pore morphologies. Hence, developing realistic models that integrate these parameters are important to understand their role in governing adsorption mechanisms that will aid in guiding the design and optimization of biochar materials for target applications. In this work, molecular dynamics simulations in the isobaric ensemble are used to generate realistic biochar models taking into account experimentally determined H/C, O/C, N/C, aromaticity, micropore size range, micropore volumes and true densities of biochars. A pore generation approach was developed using virtual atoms, which is a Lennard-Jones sphere of varying van der Waals radius and softness. Its interaction via a soft-core potential with the biochar matrix allows the creation of pores with rough surfaces while varying the van der Waals radius parameters gives control to the pore-size distribution. We focused on microporosity, creating average pore sizes of 0.5 - 2 nm in diameter and pore volumes in the range of 0.05 – 1 cm3/g, which corresponds to experimental gas adsorption micropore sizes of amorphous porous biochars. Realistic biochar models with surface functionalities, micropore size distribution and pore morphologies were developed, and they could aid in the study of adsorption processes in confined micropores.

Keywords: biochar, heteroatoms, micropore size, molecular dynamics simulations, surface functional groups, virtual atoms

Procedia PDF Downloads 53

Authors: N. Kotabin, Y. Tahara, K. Issakul, O. Chunhachart

Abstract:

Cadmium (II) (Cd) is one of the major toxic elemental pollutants which is hazardous for humans, animals and plants. γ-Polyglutamic acid (γ-PGA) is an extracellular biopolymer produced by several species of Bacillus which has been reported to be an effective biosorbent for metal ions. The effect of γ-PGA on growth of rice grown under laboratory conditions was investigated. Rice seeds were germinated and then grown at 30±1°C on filter paper soaked with Cd solution and γ-PGA for 7 days. The result showed that Cd significantly inhibited the growth of roots and shoots by reducing root and shoot lengths. Fresh and dry weights also decreased compared with control; however, the addition of 500 mg•L-1 γ-PGA alleviated rice seedlings from the adverse effects of Cd. The analysis of physiological traits revealed that Cd caused a decrease in the total chlorophyll and soluble protein contents and amylase activities in all treatments. The Cd content in seedling tissues increased for the Cd 250 μM treatment (P < 0.05) but the addition of 500 mg•L-1 γ-PGA resulted in a noticeable decrease in Cd (P < 0.05).

Keywords: polyglutamic acid, cadmium, rice, bacillus subtilis

Procedia PDF Downloads 289

Authors: Meichen Lee, Michael K. H. Leung

Abstract:

In recent years, visible-light activated photocatalysis has become a major field of intense researches for the higher efficiency of solar energy utilizations. Many attempts have been made on the modification of wide band gap semiconductors, while more and more efforts emphasize on cost-effective synthesis of visible-light activated catalysts. In this work, BiOBr nanoplates with band gap of visible-light range are synthesized through a promising microwave solvothermal method. The treatment time period and temperature dependent BiOBr nanosheets of various particle sizes are investigated through SEM. BiOBr synthesized under the condition of 160°C for 60 mins shows the most uniform particle sizes around 311 nm and the highest surface-to-volume ratio on account of its smallest average particle sizes compared with others. It exhibits the best photocatalytic behavior among all samples in RhB degradation.

Keywords: microwave solvothermal process, nanoplates, solar energy, visible-light photocatalysis

Procedia PDF Downloads 445

Authors: Mahsa Shafaei Bajestani, Mahmoud Yazdani, Aliakbar Golshani

Abstract:

Artificial lightweight aggregates have a wide range of applications in industry and engineering. Nowadays, the usage of this material in geotechnical activities, especially as backfill in retaining walls has been growing due to the specific characteristics which make it a competent alternative to the conventional geotechnical materials. In practice, a material with lower weight but higher shear strength parameters would be ideal as backfill behind retaining walls because of the important roles that these parameters play in decreasing the overall active lateral earth pressure. In this study, two types of Light Expanded Clay Aggregates (LECA) produced in the Leca factory are investigated. LECA is made in a rotary kiln by heating natural clay at different temperatures up to 1200 °C making quasi-spherical aggregates with different sizes ranged from 0 to 25 mm. The loose bulk density of these aggregates is between 300 and 700 kN/m³. The purpose of this research is to determine the stress-strain behavior, shear strength parameters, and the energy absorption of LECA materials. Direct shear tests were conducted at five normal stresses of 25, 50, 75, 100, and 200 kPa. In addition, conventional triaxial compression tests were operated at confining pressures of 50, 100, and 200 kPa to examine stress-strain behavior. The experimental results show a high internal angle of friction and even a considerable amount of nominal cohesion despite the granular structure of LECA. These desirable properties along with the intrinsic low density of these aggregates make LECA as a very proper material in geotechnical applications. Furthermore, the results demonstrate that lightweight aggregates may have high energy absorption that is excellent alternative material in seismic isolations.

Keywords: expanded clay, direct shear test, triaxial test, shear properties, energy absorption

Procedia PDF Downloads 146