Search results for: side angle of fracture
Commenced in January 2007
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Edition: International
Paper Count: 3912

Search results for: side angle of fracture

672 Correlation of Structure and Antiviral Activity of Alkaloids of Polygonum L. Plants Growing in Kazakhstan

Authors: Dmitry Yu. Korulkin, Raissa A. Muzychkina

Abstract:

Currently to treat infectious diseases bioactive substances of plant origin having fewer side effects than synthetic medicines and medicines similar to natural components of a human body by the structure and action, become very important. One of the groups of secondary metabolites of the plants - alkaloids can be related the number of the most promising sources of medicines of plant origin. Currently, the structure of more than 7500 compounds has been identified. Analyzing the scope of research in the field of chemistry, pharmacology and technology of alkaloids, we can make a conclusion about that there is no system approach during the research of relation structure-activity on different groups of these substances. It is connected not only with a complex structure of their molecules, but also with insufficient information on the nature of their effect on organs, tissues and other targets in organism. The purpose of this research was to identify pharmacophore groups in the structure of alkaloids of endemic Polygonum L. plants growing in Kazakhstan responsible for their antiviral action. To isolate alkaloids pharmacopoeian methods were used. Antiviral activity of alkaloids of Polygonum L. plants was researched in the Institute of Microbiology and Virology of the Ministry of Education and Science of the Republic of Kazakhstan. Virus-inhibiting properties of compounds were studies in experiments with ortho- and paramyxoviruses on the model of chick-embryos. Anti-viral properties were determined using ‘screening test’ method designed to neutralization of a virus at the amount of 100EID50 with set concentrations of medicines. The difference of virus titer compared to control group was deemed as the criterion of antiviral action. It has been established that Polygonum L. alkaloids has high antiviral effect to influenza and parainfluenza viruses. The analysis of correlation of the structure and antiviral activity of alkaloids allowed identifying the main pharmacophore groups, among which the most important are glycosidation, the presence of carbonyl and hydroxyl groups, molecular weight and molecular size.

Keywords: alkaloids, antiviral, bioactive substances, isolation, pharmacophore groups, Polygonum L.

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671 Submarine Topography and Beach Survey of Gang-Neung Port in South Korea, Using Multi-Beam Echo Sounder and Shipborne Mobile Light Detection and Ranging System

Authors: Won Hyuck Kim, Chang Hwan Kim, Hyun Wook Kim, Myoung Hoon Lee, Chan Hong Park, Hyeon Yeong Park

Abstract:

We conducted submarine topography & beach survey from December 2015 and January 2016 using multi-beam echo sounder EM3001(Kongsberg corporation) & Shipborne Mobile LiDAR System. Our survey area were the Anmok beach in Gangneung, South Korea. We made Shipborne Mobile LiDAR System for these survey. Shipborne Mobile LiDAR System includes LiDAR (RIEGL LMS-420i), IMU ((Inertial Measurement Unit, MAGUS Inertial+) and RTKGNSS (Real Time Kinematic Global Navigation Satellite System, LEIAC GS 15 GS25) for beach's measurement, LiDAR's motion compensation & precise position. Shipborne Mobile LiDAR System scans beach on the movable vessel using the laser. We mounted Shipborne Mobile LiDAR System on the top of the vessel. Before beach survey, we conducted eight circles IMU calibration survey for stabilizing heading of IMU. This exploration should be as close as possible to the beach. But our vessel could not come closer to the beach because of latency objects in the water. At the same time, we conduct submarine topography survey using multi-beam echo sounder EM3001. A multi-beam echo sounder is a device observing and recording the submarine topography using sound wave. We mounted multi-beam echo sounder on left side of the vessel. We were equipped with a motion sensor, DGNSS (Differential Global Navigation Satellite System), and SV (Sound velocity) sensor for the vessel's motion compensation, vessel's position, and the velocity of sound of seawater. Shipborne Mobile LiDAR System was able to reduce the consuming time of beach survey rather than previous conventional methods of beach survey.

Keywords: Anmok, beach survey, Shipborne Mobile LiDAR System, submarine topography

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670 Realistic Modeling of the Preclinical Small Animal Using Commercial Software

Authors: Su Chul Han, Seungwoo Park

Abstract:

As the increasing incidence of cancer, the technology and modality of radiotherapy have advanced and the importance of preclinical model is increasing in the cancer research. Furthermore, the small animal dosimetry is an essential part of the evaluation of the relationship between the absorbed dose in preclinical small animal and biological effect in preclinical study. In this study, we carried out realistic modeling of the preclinical small animal phantom possible to verify irradiated dose using commercial software. The small animal phantom was modeling from 4D Digital Mouse whole body phantom. To manipulate Moby phantom in commercial software (Mimics, Materialise, Leuven, Belgium), we converted Moby phantom to DICOM image file of CT by Matlab and two- dimensional of CT images were converted to the three-dimensional image and it is possible to segment and crop CT image in Sagittal, Coronal and axial view). The CT images of small animals were modeling following process. Based on the profile line value, the thresholding was carried out to make a mask that was connection of all the regions of the equal threshold range. Using thresholding method, we segmented into three part (bone, body (tissue). lung), to separate neighboring pixels between lung and body (tissue), we used region growing function of Mimics software. We acquired 3D object by 3D calculation in the segmented images. The generated 3D object was smoothing by remeshing operation and smoothing operation factor was 0.4, iteration value was 5. The edge mode was selected to perform triangle reduction. The parameters were that tolerance (0.1mm), edge angle (15 degrees) and the number of iteration (5). The image processing 3D object file was converted to an STL file to output with 3D printer. We modified 3D small animal file using 3- Matic research (Materialise, Leuven, Belgium) to make space for radiation dosimetry chips. We acquired 3D object of realistic small animal phantom. The width of small animal phantom was 2.631 cm, thickness was 2.361 cm, and length was 10.817. Mimics software supported efficiency about 3D object generation and usability of conversion to STL file for user. The development of small preclinical animal phantom would increase reliability of verification of absorbed dose in small animal for preclinical study.

Keywords: mimics, preclinical small animal, segmentation, 3D printer

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669 Smallholder Participation in Organized Retail Markets: Evidence from India

Authors: Kedar Vishnu, Parmod Kumar

Abstract:

India is becoming most favored retail destination in the world. The organized retail has presented many opportunities to farmers to increase income by shifting cropping pattern from food grains to commercial crops. Previous research revealed potential benefits for farmers by supplying fruits and vegetables to organized retail channels. However the supply of fruits and vegetables from small and marginal farmers remain low than expected. The main objective of this paper is to identify the factors determining market participation of smallholder farmers in modern organized retail chains. Attempt is also made to find out factors influencing the choice of participation in particular organized retail collection centers as compared to other organized retail. The paper was based on primary survey of 40 Beans and Tomato farmers who supply to organized retail collection centers from Karnataka, India. Multiple regression technique is used to identify the factors determining quantity sold at collection centers. The regression result, show that area under vegetables, yield, and price from modern collection center and having access to technical help were found significantly affecting quantity sold into modern organized retail channels. On the opposite, increased rejection rates and vegetable prices at APMC were found influencing farmers decision into the reverse side. Empirical result of the multinomial logit model show that Reliance fresh has tendency to prefer large farmers who can supply more quality and better quantity compared with TESCO and More collection centers. The negative sign of area, having access to technical help, transportation cost, and number of bore wells led to higher probability of farmers to participate in Reliance Fresh collection centers as compared with More and TESCO.

Keywords: fruits, vegetables, organized retail markets, multinomial logit model

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668 Study Secondary Particle Production in Carbon Ion Beam Radiotherapy

Authors: Shaikah Alsubayae, Gianluigi Casse, Carlos Chavez, Jon Taylor, Alan Taylor, Mohammad Alsulimane

Abstract:

Ensuring accurate radiotherapy with carbon therapy requires precise monitoring of radiation dose distribution within the patient's body. This monitoring is essential for targeted tumor treatment, minimizing harm to healthy tissues, and improving treatment effectiveness while lowering side effects. In our investigation, we employed a methodological approach to monitor secondary proton doses in carbon therapy using Monte Carlo simulations. Initially, Geant4 simulations were utilized to extract the initial positions of secondary particles formed during interactions between carbon ions and water. These particles included protons, gamma rays, alpha particles, neutrons, and tritons. Subsequently, we studied the relationship between the carbon ion beam and these secondary particles. Interaction Vertex Imaging (IVI) is valuable for monitoring dose distribution in carbon therapy. It provides details about the positions and amounts of secondary particles, particularly protons. The IVI method depends on charged particles produced during ion fragmentation to gather information about the range by reconstructing particle trajectories back to their point of origin, referred to as the vertex. In our simulations regarding carbon ion therapy, we observed a strong correlation between some secondary particles and the range of carbon ions. However, challenges arose due to the target's unique elongated geometry, which hindered the straightforward transmission of forward-generated protons. Consequently, the limited protons that emerged mostly originated from points close to the target entrance. The trajectories of fragments (protons) were approximated as straight lines, and a beam back-projection algorithm, using recorded interaction positions in Si detectors, was developed to reconstruct vertices. The analysis revealed a correlation between the reconstructed and actual positions.

Keywords: radiotherapy, carbon therapy, monitoring of radiation dose, interaction vertex imaging

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667 The Feasibility of a Protected Launch Site near Melkbosstrand for a Public Transport Ferry across Table Bay, Cape Town

Authors: Mardi Falck, André Theron

Abstract:

Traffic congestion on the Northern side of Table Bay is a major problem. In Gauteng, the implementation of the Gautrain between Pretoria and Johannesburg, solved their traffic congestion. In 2002 two entrepreneurs endeavoured to implement a hovercraft ferry service across the bay from Table View to the Port of Cape Town. However, the EIA process proved that disgruntled residents from the area did not agree with their location for a launch site. 17 years later the traffic problem has not gone away, but instead the congestion has increased. While property prices in the City Bowl of Cape Town are ever increasing, people tend to live more on the outskirts of the CBD and commute to work. This means more vehicles on the road every day and the public transport services cannot keep up with the demand. For this reason, the study area of the previous hovercraft plans is being extended further North. The study’s aim is thus to determine the feasibility of a launch site North of Bloubergstrand to launch and receive a public transport ferry across Table Bay. The feasibility is being established by researching ferry services across the world and on what makes them successful. Different types of ferries and their operational capacities in terms of weather and waves are researched and by establishing the offshore and nearshore wind and wave climate for the area, an appropriate protected launch site is determined. It was concluded that travel time could potentially be halved. A hovercraft proved to be the most feasible ferry type, because it does not require a conventional harbour. Other types of vessels require a protected launch site because of the wave climate. This means large breakwaters that influence the cost substantially. The Melkbos Cultural Centre proved to be the most viable option for the location of the launch site, because it already has buildings and infrastructure. It is recommended that, if a harbour is chosen for the proposed ferry service, it could be used for more services like fishing, eco-tourism and leisure. Further studies are recommended to optimise the feasibility of such a harbour.

Keywords: Cape Town, ferry, public, Table Bay

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666 Mesoporous Titania Thin Films for Gentamicin Delivery and Bone Morphogenetic Protein-2 Immobilization

Authors: Ane Escobar, Paula Angelomé, Mihaela Delcea, Marek Grzelczak, Sergio Enrique Moya

Abstract:

The antibacterial capacity of bone-anchoring implants can be improved by the use of antibiotics that can be delivered to the media after the surgery. Mesoporous films have shown great potential in drug delivery for orthopedic applications, since pore size and thickness can be tuned to produce different surface area and free volume inside the material. This work shows the synthesis of mesoporous titania films (MTF) by sol-gel chemistry and evaporation-induced self-assembly (EISA) on top of glass substrates. Pores with a diameter of 12nm were observed by Transmission Electron Microscopy (TEM). A film thickness of 100 nm was measured by Scanning Electron Microscopy (SEM). Gentamicin was used to study the antibiotic delivery from the film by means of High-performance liquid chromatography (HPLC). The Staphilococcus aureus strand was used to evaluate the effectiveness of the penicillin loaded films toward inhibiting bacterial colonization. MC3T3-E1 pre-osteoblast cell proliferation experiments proved that MTFs have a good biocompatibility and are a suitable surface for MC3T3-E1 cell proliferation. Moreover, images taken by Confocal Fluorescence Microscopy using labeled vinculin, showed good adhesion of the MC3T3-E1 cells to the MTFs, as well as complex actin filaments arrangement. In order to improve cell proliferation Bone Morphogenetic Protein-2 (BMP-2) was adsorbed on top of the mesoporous film. The deposition of the protein was proved by measurements in the contact angle, showing an increment in the hydrophobicity while the protein concentration is higher. By measuring the dehydrogenase activity in MC3T3-E1 cells cultured in dually functionalized mesoporous titatina films with gentamicin and BMP-2 is possible to find an improvement in cell proliferation. For this purpose, the absorption of a yellow-color formazan dye, product of a water-soluble salt (WST-8) reduction by the dehydrogenases, is measured. In summary, this study proves that by means of the surface modification of MTFs with proteins and loading of gentamicin is possible to achieve an antibacterial effect and a cell growth improvement.

Keywords: antibacterial, biocompatibility, bone morphogenetic protein-2, cell proliferation, gentamicin, implants, mesoporous titania films, osteoblasts

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665 The Impact of Corporate Governance Mechanisms on Earnings Management Practices: Evidence from Jordan

Authors: Lara Al-Haddad, Mark Whittington

Abstract:

This paper aims to examine the impact of two influential internal corporate governance mechanisms, namely board characteristics and ownership structure on the use of real activities-based and accrual-based earnings management by Jordanian public firms. Using panel data from Jordanian public firms after the introduction of the Jordanian Corporate Governance Code (JCGC) in 2009, the study finds both institutional ownership and managerial ownership constrain the use of real and accrual earnings manipulations. On the other side, both independent directors and largest shareholders are found to exaggerate the incidence of using real and accrual earnings management. The study also examines the trade-off between real and accrual earnings management and found that Jordanian firms use a combination of real and accrual-based earnings management to obtain the greatest effect on earnings reporting strategies. For the purpose of this study, three types of real earnings management are considered: sales manipulation, overproduction, and the abnormal reduction of discretionary expenditures. The abnormal discretionary accrual is considered for accruals management. While for the internal corporate governance mechanisms; board characteristics are examined by using board independence, board size, and CEO-duality; and ownership structure is examined by using managerial ownership, institutional ownership, foreign ownership and largest shareholder ownership. To the best knowledge of the researchers, this study is the first to examine the relationship between board characteristics and real earnings management in Jordan. Further, it is the first to examine the relationship between corporate governance mechanisms and discretionary accruals after the introduction of the Jordanian Corporate Governance Code in 2009. Thus, the findings of this study have important policy implications for policymakers, regulators, standard setters, audit professional, and investors in their attempts to constrain the practice of earnings management, whether real or accrual, and to improve the financial reporting quality in Jordan.

Keywords: board characteristics, Jordan, ownership structure, real earnings management

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664 The Effects of High-frequency rTMS Targeting the Mirror Neurons on Improving Social Awareness in ASD, the Preliminary Analysis of a Pilot Study

Authors: Mitra Assadi, Md. Faan

Abstract:

Background: Autism Spectrum Disorder (ASD) in a common neurodevelopmental disorder with limited pharmacological interventions. Transcranial Magnetic Stimulation (rTMS) has produced promising results in ASD, although there is no consensus regarding optimal targets or stimulation paradigms. A prevailing theory in ASD attributes the core deficits to dysfunction of the mirror neurons located in the inferior parietal lobule (IPL) and inferior frontal gyrus (IFG). Methods: Thus far, 11 subjects with ASD, 10 boys and 1 girl with the mean age of 13.36 years have completed the study by receiving 10 session of high frequency rTMS to the IPL. The subjects were randomized to receive stimulation on the left or right IPL and sham stimulation to the opposite side. The outcome measures included the Social Responsiveness Scale – Second Edition (SRS-2) and Delis-Kaplan Executive Function System (D-KEFS) Verbal Fluency task. Results: None of the 11 subjects experienced any adverse effects. The rTMS did not produce any improvement in verbal fluency, nor there was any statistically significant difference between the right versus left sided stimulation. Analysis of social awareness on SRS-2 (SRS-AWR) indicated a close to significant effect of the treatment with a small to medium effect size. After removing a single subject with Level 3 ASD, we demonstrated a close to significant improvement on SRS-AWR with a large effect size. The analysis of the data 3-month post TMS demonstrated return of the SRS-AWR values to baseline. Conclusion: This preliminary analysis of the 11 subjects who have completed our study thus far shows a favorable response to high frequency rTMS stimulation of the mirror neurons/IPL on social awareness. While the decay of the response noted during the 3-month follow-up may be considered a limitation of rTMS, the presence of the improvement, especially the effect size despite the small sample size, is indicative of the efficacy of this technique.

Keywords: rTMS, autism, scoial cognition, mirror neurons

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663 Pioglitazone Ameliorates Methotrexate-Induced Renal Endothelial Dysfunction via Amending Detrimental Changes in Antioxidant Profile, Systemic Cytokines and Apoptotic Factors

Authors: Sahar M. El-Gowilly, Mai M. Helmy, Hanan M. El-Gowelli

Abstract:

Methotrexate (MTX) is widely used in treatment of cancers and autoimmune diseases. However, nephrotoxicity is one of the most important side effects of MTX. The peroxisome proliferator-activated receptor gamma agonist, pioglitazone (PIO), is known to exert anti-inflammatory and reno-protective effects in various kidney injuries. The purpose of this study was to investigate the potential involvement of endothelial damage in MTX-induced renal injury and to elaborate the possible protective effect of PIO against MTX-induced nephropathy. Compared with saline-treated rats, treatment with MTX (7 mg/kg for 3 day) caused significant elevations in serum levels of urea and creatinine, increased renal nitrate/nitrite level and impaired renovascular responsiveness of isolated perfused kidney to endothelium-dependent vasodilations induced by acetylcholine (0.01-2.43 nmol) and isoprenaline (1µmol). These effects were abolished by concurrent treatment with PIO (2.5 mg/kg, for 5 days starting two days before MTX). Alternatively, MTX treatment did not affect endothelium-independent renovascular relaxation induced by sodium nitroprusside (1-30 μmole). The possibility that alterations in renal antioxidants, circulating cytokine and apoptotic factor (Fas) levels contributed to MTX-PIO interaction was assessed. PIO treatment abrogated renal oxidative stress (decreased reduced glutathione and catalase activity and increased malondialdehyde), elevated serum cytokine (interleukin-6, interleukin-10, tumor necrosis factor-alpha and transforming growth factor-beta1) and Fas induced by MTX. Histologically, MTX caused defused tubular cells swelling and vacuolization associated with endothelial damage in renal arterioles. These effects disappeared upon co-treated with PIO. Collectively, PIO abolished MTX-induced endothelium dysfunction and nephrotoxicity via ameliorating oxidative stress and rectifying cytokines and Fas abnormalities caused by MTX.

Keywords: methotrexate, pioglitazone, endothelium, kidney

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662 Providing Healthy Food in Primary and Secondary Schools of Saudi Arabia to Significantly Reduce Obesity and Improve Health by Using the Star Rating System for a Healthier Diet

Authors: Emran M. Badghish

Abstract:

Overweight and obesity have now become an epidemic around the globe, both in high-, as well as low-income regions. It is important to use preventive measures that are cost-effective. Schools are the essence of building societies and engaging them in healthy nutrition will offer a way to reach individuals at an early stage in life, with many positive and significant impacts. Aim: Provide healthy food in schools of children aged 5 to 18 years old. Methods: Distributing healthy food to a school and implementation of a star rating system for healthier foods, with five stars for the healthiest option to a half a star for the unhealthiest. The stars system was developed in Australia and should motivate children to consume the healthier nutritional options. Each canteen should be allowed a minimum of 3.5 stars rating for the food provided. Outcome Measurement: Body-mass-index as an indicator of overweight and obesity should be checked at the beginning of the study annually for five years for all children. Another side measurement is the performance by checking the grades and a questionnaire on eating habits at the start of the study and yearly. Expected Outcome: A lower health-risk behaviour and assistance to children in reaching their potentials as they will adapt to eating healthier. Nutrition during childhood has the potential to prevent obesity, type 2 diabetes, dental diseases, hypertension and, in later life, cardiovascular disease, osteoporosis and a variety of cancers. In Australia NSW starting from 2016 is expecting a 5% reduction of childhood overweight and obesity by 2025. As for Saudi-Arabia, it is expected to have an, even more, reduction by 2023 as a lot of our children are canteen-dependent. Conclusion: Introducing healthy food in schools is a preventative method that would have significant influence on the reduction of the prevalence of obesity in Saudi-Arabia and improves its general health.

Keywords: food, healthy, children, obesity, schools

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661 High Unmet Need and Factors Associated with Utilization of Contraceptive Methods among Women from the Digo Community of Kwale, Kenya

Authors: Mochache Vernon, Mwakusema Omar, Lakhani Amyn, El Busaidy Hajara, Temmerman Marleen, Gichangi Peter

Abstract:

Background: Utilization of contraceptive methods has been associated with improved maternal and child health (MCH) outcomes. Unfortunately, there has been sub-optimal uptake of contraceptive services in the developing world despite significant resources being dedicated accordingly. It is imperative to granulate factors that could influence uptake and utilization of contraception. Methodology: Between March and December 2015, we conducted a mixed-methods cross-sectional study among women of reproductive age (18-45 years) from a pre-dominantly rural coastal Kenyan community. Qualitative approaches involved focus group discussions as well as a series of key-informant interviews. We also administered a sexual and reproductive health survey questionnaire at the household level. Results: We interviewed 745 women from 15 villages in Kwale County. The median (interquartile range, IQR) age was 29 (23-37) while 76% reported being currently in a marital union. Eighty-seven percent and 85% of respondents reported ever attending school and ever giving birth, respectively. Respondents who had ever attended school were more than twice as likely to be using contraceptive methods [Odds Ratio, OR = 2.1, 95% confidence interval, CI: 1.4-3.4, P = 0.001] while those who had ever given birth were five times as likely to be using these methods [OR = 5.0, 95% CI: 1.7-15.0, P = 0.004]. The odds were similarly high among women who reported attending antenatal care (ANC) [OR = 4.0, 95% CI: 1.1-14.8, P = 0.04] as well as those who expressly stated that they did not want any more children or wanted to wait longer before getting another child [OR = 6.7, 95% CI: 3.3-13.8, P<0.0001]. Interviewees reported deferring to the ‘wisdom’ of an older maternal figure in the decision-making process. Conclusions: Uptake and utilization of contraceptive methods among Digo women from Kwale, Kenya is positively associated with demand-side factors including educational attainment, previous birth experience, ANC attendance and a negative future fertility desire. Interventions to improve contraceptive services should focus on engaging dominant maternal figures in the community.

Keywords: unmet need, utilization of contraceptive methods, women, Digo community

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660 An Intelligent Steerable Drill System for Orthopedic Surgery

Authors: Wei Yao

Abstract:

A steerable and flexible drill is needed in orthopaedic surgery. For example, osteoarthritis is a common condition affecting millions of people for which joint replacement is an effective treatment which improves the quality and duration of life in elderly sufferers. Conventional surgery is not very accurate. Computer navigation and robotics can help increase the accuracy. For example, In Total Hip Arthroplasty (THA), robotic surgery is currently practiced mainly on acetabular side helping cup positioning and orientation. However, femoral stem positioning mostly uses hand-rasping method rather than robots for accurate positioning. The other case for using a flexible drill in surgery is Anterior Cruciate Ligament (ACL) Reconstruction. The majority of ACL Reconstruction failures are primarily caused by technical mistakes and surgical errors resulting from drilling the anatomical bone tunnels required to accommodate the ligament graft. The proposed new steerable drill system will perform orthopedic surgery through curved tunneling leading to better accuracy and patient outcomes. It may reduce intra-operative fractures, dislocations, early failure and leg length discrepancy by making possible a new level of precision. This technology is based on a robotically assisted, steerable, hand-held flexible drill, with a drill-tip tracking device and a multi-modality navigation system. The critical differentiator is that this robotically assisted surgical technology now allows the surgeon to prepare 'patient specific' and more anatomically correct 'curved' bone tunnels during orthopedic surgery rather than drilling straight holes as occurs currently with existing surgical tools. The flexible and steerable drill and its navigation system for femoral milling in total hip arthroplasty had been tested on sawbones to evaluate the accuracy of the positioning and orientation of femoral stem relative to the pre-operative plan. The data show the accuracy of the navigation system is better than traditional hand-rasping method.

Keywords: navigation, robotic orthopedic surgery, steerable drill, tracking

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659 Characterisation of Chitooligomers Prepared with the Aid of Cellulase, Xylanase and Chitosanase

Authors: Anna Zimoch-Korzycka, Dominika Kulig, Andrzej Jarmoluk

Abstract:

The aim of this study was to obtain chitooligosaccharides from chitosan with better functional properties using three different enzyme preparations and compare the products of enzymatic hydrolysis. Commercially available cellulase (CL), xylanase (X) and chitosanase (CS) preparations were used to investigate hydrolytic activity on chitosan (CH) with low molecular weight and DD of 75-85%. It has been reported that CL and X have side activities of other enzymes, such as β-glucanase or β-glucosidase. CS enzyme has a foreign activity of chitinase. Each preparation was used in 1000 U of activity and in the same reaction conditions. The degree of deacetylation and molecular weight of chitosan were specified using titration and viscometric methods, respectively. The hydrolytic activity of enzymes preparations on chitosan was monitored by dynamic viscosity measurement. After 4 h reaction with stirring, solutions were filtered and chitosan oligomers were isolated by methanol solution into two fractions: precipitate (A) and supernatant (B). A Fourier-transform infrared spectroscopy was used to characterize the structural changes of chitosan oligomers fractions and initial chitosan. Furthermore, the solubility of lyophilized hydrolytic mixture (C) and two chitooligomers fractions (A, B) of each enzyme hydrolysis was assayed. The antioxidant activity of chitosan oligomers was evaluated as DPPH free radical scavenging activity. The dynamic viscosity measured after addition of enzymes preparation to the chitosan solution decreased dramatically over time in the sample with X in comparison to solution without the enzyme. For mixtures with CL and CS, lower viscosities were also recorded but not as low as the ones with X. A and B fractions were characterized by the most similar viscosity obtained by the xylanase hydrolysis and were 15 mPas and 9 mPas, respectively. Structural changes of chitosan oligomers A, B, C and their differences related with various enzyme preparations used were confirmed. Water solubility of A fractions was not possible to filter and the result was not recorded. Solubility of supernatants was approximately 95% and was higher than hydrolytic mixture. It was observed that the DPPH radical scavenging effect of A, B, C samples is the highest for X products and was approximately 13, 17, 19% respectively. In summary, a mixture of chitooligomers may be useful for the design of edible protective coatings due to the improved biophysical properties.

Keywords: cellulase, xylanase, chitosanase, chitosan, chitooligosaccharides

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658 Pioglitazone Ameliorates Methotrexate-Induced Renal Endothelial Dysfunction via Amending Detrimental Changes in Antioxidant Profile, Systemic Cytokines and Fas Production

Authors: Sahar M. El-Gowilly, Mai M. Helmy, Hanan M. El-Gowelli

Abstract:

Methotrexate (MTX) is widely used in treatment of cancers and autoimmune diseases. However, nephrotoxicity is one of its most important side effects. The peroxisome proliferator-activated receptor gamma agonist, pioglitazone, is known to exert antiinflammatory and reno-protective effects in various kidney injuries. The purpose of this study was to investigate the potential involvement of endothelial damage in MTX-induced renal injury and to elaborate the possible protective effect of pioglitazone against MTX-induced endothelial impairment. Compared with saline-treated rats, treatment with MTX (7 mg/kg for 3 day) caused significant elevations in serum levels of urea and creatinine, increased renal nitrate/nitrite level and impaired renovascular responsiveness of isolated perfused kidney to endothelium-dependent vasodilations induced by acetylcholine (0.01-2.43 nmol) and isoprenaline (1µmol). These effects were abolished by concurrent treatment with pioglitazone (2.5 mg/kg, for 5 days starting two days before MTX). Alternatively, MTX treatment did not affect endothelium-independent renovascular relaxation induced by sodium nitroprusside (0.001-10 μmole). The possibility that alterations in renal antioxidants, circulating cytokine and apoptotic factor (Fas) levels contributed to MTX-pioglitazone interaction was assessed. Pioglitazone treatment abrogated renal oxidative stress (decreased reduced glutathione and catalase activity and increased malondialdehyde), elevated serum cytokine (interleukin-6, interleukin-10, tumor necrosis factor-alpha and transforming growth factor-beta1) and Fas induced by MTX. Histologically, MTX caused defused tubular cells swelling and vacuolization associated with endothelial damage in renal arterioles. These effects disappeared upon co-treated with pioglitazone. Collectively, pioglitazone abolished MTX-induced endothelium dysfunction and nephrotoxicity via ameliorating oxidative stress and rectifying cytokines and Fas abnormalities caused by MTX.

Keywords: methotrexate, pioglitazone, endothelium, kidney

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657 Advancing Entrepreneurial Knowledge Through Re-Engineering Social Studies Education

Authors: Chukwuka Justus Iwegbu, Monye Christopher Prayer

Abstract:

Propeller aircraft engines, and more generally engines with a large rotating part (turboprops, high bypass ratio turbojets, etc.) are widely used in the industry and are subject to numerous developments in order to reduce their fuel consumption. In this context, unconventional architectures such as open rotors or distributed propulsion appear, and it is necessary to consider the influence of these systems on the aircraft's stability in flight. Indeed, the tendency to lengthen the blades and wings on which these propulsion devices are fixed increases their flexibility and accentuates the risk of whirl flutter. This phenomenon of aeroelastic instability is due to the precession movement of the axis of rotation of the propeller, which changes the angle of attack of the flow on the blades and creates unsteady aerodynamic forces and moments that can amplify the motion and make it unstable. The whirl flutter instability can ultimately lead to the destruction of the engine. We note the existence of a critical speed of the incident flow. If the flow velocity is lower than this value, the motion is damped and the system is stable, whereas beyond this value, the flow provides energy to the system (negative damping) and the motion becomes unstable. A simple model of whirl flutter is based on the work of Houbolt & Reed who proposed an analytical expression of the aerodynamic load on a rigid blade propeller whose axis orientation suffers small perturbations. Their work considered a propeller subjected to pitch and yaw movements, a flow undisturbed by the blades and a propeller not generating any thrust in the absence of precession. The unsteady aerodynamic forces were then obtained using the thin airfoil theory and the strip theory. In the present study, the unsteady aerodynamic loads are expressed for a general movement of the propeller (not only pitch and yaw). The acceleration and rotation of the flow by the propeller are modeled using a Blade Element Momentum Theory (BEMT) approach, which also enable to take into account the thrust generated by the blades. It appears that the thrust has a stabilizing effect. The aerodynamic model is further developed using Theodorsen theory. A reduced order model of the aerodynamic load is finally constructed in order to perform linear stability analysis.

Keywords: advancing, entrepreneurial, knowledge, industralization

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656 Fully Coupled Porous Media Model

Authors: Nia Mair Fry, Matthew Profit, Chenfeng Li

Abstract:

This work focuses on the development and implementation of a fully implicit-implicit, coupled mechanical deformation and porous flow, finite element software tool. The fully implicit software accurately predicts classical fundamental analytical solutions such as the Terzaghi consolidation problem. Furthermore, it can capture other analytical solutions less well known in the literature, such as Gibson’s sedimentation rate problem and Coussy’s problems investigating wellbore stability for poroelastic rocks. The mechanical volume strains are transferred to the porous flow governing equation in an implicit framework. This will overcome some of the many current industrial issues, which use explicit solvers for the mechanical governing equations and only implicit solvers on the porous flow side. This can potentially lead to instability and non-convergence issues in the coupled system, plus giving results with an accountable degree of error. The specification of a fully monolithic implicit-implicit coupled porous media code sees the solution of both seepage-mechanical equations in one matrix system, under a unified time-stepping scheme, which makes the problem definition much easier. When using an explicit solver, additional input such as the damping coefficient and mass scaling factor is required, which are circumvented with a fully implicit solution. Further, improved accuracy is achieved as the solution is not dependent on predictor-corrector methods for the pore fluid pressure solution, but at the potential cost of reduced stability. In testing of this fully monolithic porous media code, there is the comparison of the fully implicit coupled scheme against an existing staggered explicit-implicit coupled scheme solution across a range of geotechnical problems. These cases include 1) Biot coefficient calculation, 2) consolidation theory with Terzaghi analytical solution, 3) sedimentation theory with Gibson analytical solution, and 4) Coussy well-bore poroelastic analytical solutions.

Keywords: coupled, implicit, monolithic, porous media

Procedia PDF Downloads 126
655 The Pore–Scale Darcy–Brinkman–Stokes Model for the Description of Advection–Diffusion–Precipitation Using Level Set Method

Authors: Jiahui You, Kyung Jae Lee

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Hydraulic fracturing fluid (HFF) is widely used in shale reservoir productions. HFF contains diverse chemical additives, which result in the dissolution and precipitation of minerals through multiple chemical reactions. In this study, a new pore-scale Darcy–Brinkman–Stokes (DBS) model coupled with Level Set Method (LSM) is developed to address the microscopic phenomena occurring during the iron–HFF interaction, by numerically describing mass transport, chemical reactions, and pore structure evolution. The new model is developed based on OpenFOAM, which is an open-source platform for computational fluid dynamics. Here, the DBS momentum equation is used to solve for velocity by accounting for the fluid-solid mass transfer; an advection-diffusion equation is used to compute the distribution of injected HFF and iron. The reaction–induced pore evolution is captured by applying the LSM, where the solid-liquid interface is updated by solving the level set distance function and reinitialized to a signed distance function. Then, a smoothened Heaviside function gives a smoothed solid-liquid interface over a narrow band with a fixed thickness. The stated equations are discretized by the finite volume method, while the re-initialized equation is discretized by the central difference method. Gauss linear upwind scheme is used to solve the level set distance function, and the Pressure–Implicit with Splitting of Operators (PISO) method is used to solve the momentum equation. The numerical result is compared with 1–D analytical solution of fluid-solid interface for reaction-diffusion problems. Sensitivity analysis is conducted with various Damkohler number (DaII) and Peclet number (Pe). We categorize the Fe (III) precipitation into three patterns as a function of DaII and Pe: symmetrical smoothed growth, unsymmetrical growth, and dendritic growth. Pe and DaII significantly affect the location of precipitation, which is critical in determining the injection parameters of hydraulic fracturing. When DaII<1, the precipitation uniformly occurs on the solid surface both in upstream and downstream directions. When DaII>1, the precipitation mainly occurs on the solid surface in an upstream direction. When Pe>1, Fe (II) transported deeply into and precipitated inside the pores. When Pe<1, the precipitation of Fe (III) occurs mainly on the solid surface in an upstream direction, and they are easily precipitated inside the small pore structures. The porosity–permeability relationship is subsequently presented. This pore-scale model allows high confidence in the description of Fe (II) dissolution, transport, and Fe (III) precipitation. The model shows fast convergence and requires a low computational load. The results can provide reliable guidance for injecting HFF in shale reservoirs to avoid clogging and wellbore pollution. Understanding Fe (III) precipitation, and Fe (II) release and transport behaviors give rise to a highly efficient hydraulic fracture project.

Keywords: reactive-transport , Shale, Kerogen, precipitation

Procedia PDF Downloads 152
654 Extraction, Characterization, and Applicability of Rich β-Glucan Fractions from Fungal Biomass

Authors: Zaida Perez-Bassart, Berta Polanco-Estibalez, Maria Jose Fabra, Amparo Lopez-Rubio, Antonio Martinez-Abad

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Mushroom production has enormously increased in recent years, not only as food products but also for applications in pharmaceuticals, nutraceuticals, and cosmetics. Consequently, interest in its chemical composition, nutritional value, and therapeutic properties has also increased. Fungi are rich in bioactive compounds such as polysaccharides, polyphenols, glycopeptides, and ergosterol, of great medicinal value, but within polysaccharides, β-glucans are the most prominent molecules. They are formed by D-glucose monomers, linked by β-glucosidic bonds β-(1,3) with side chains linked by β-(1,6) bonds. The number and position of the β-(1,6) branches strongly influence the arrangement of the tertiary structure, which, together with the molecular weight, determine the different attributed bioactivities (immunostimulating, anticancer, antimicrobial, prebiotic, etc.) and physico-chemical properties (solubility, bioaccessibility, viscosity or emulsifying). On the other hand, there is a growing interest in the study of fungi as an alternative source of chitin obtained from the by-products of the fungal industry. In this work, a cascade extraction process using aqueous neutral and alkaline treatments was carried out for Grifola frondosa and Lentinula edodes, and the compositional analysis and functional properties of each fraction were characterized. Interestingly, the first fraction obtained by using aqueous treatment at room temperature was the richest in polysaccharides, proteins, and polyphenols, thus obtaining a greater antioxidant capacity than in the other fractions. In contrast, the fractions obtained by alkaline treatments showed a higher degree of β-glucans purification compared to aqueous extractions but a lower extraction yield. Results revealed the different structural recalcitrance of β-glucans, preferentially linked to proteins or chitin depending on the fungus type, which had a direct impact on the functionalities and bioactivities of each fraction.

Keywords: fungi, mushroom, β-glucans, chitin

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653 Green-Synthesized β-Cyclodextrin Membranes for Humidity Sensors

Authors: Zeineb Baatout, Safa Teka, Nejmeddine Jaballah, Nawfel Sakly, Xiaonan Sun, Mustapha Majdoub

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Currently, the economic interests linked to the development of bio-based materials make biomass one of the most interesting areas for science development. We are interested in the β-cyclodextrin (β-CD), one of the popular bio-sourced macromolecule, produced from the starch via enzymatic conversion. It is a cyclic oligosaccharide formed by the association of seven glucose units. It presents a rigid conical and amphiphilic structure with hydrophilic exterior, allowing it to be water-soluble. It has also a hydrophobic interior enabling the formation of inclusion complexes, which support its application for the elaboration of electrochemical and optical sensors. Nevertheless, the solubility of β-CD in water makes its use as sensitive layer limit and difficult due to their instability in aqueous media. To overcome this limitation, we chose to precede by modification of the hydroxyl groups to obtain hydrophobic derivatives which lead to water-stable sensing layers. Hence, a series of benzylated β-CDs were synthesized in basic aqueous media in one pot. This work reports the synthesis of a new family of substituted amphiphilic β-CDs using a green methodology. The obtained β-CDs showed different degree of substitution (DS) between 0.85 and 2.03. These organic macromolecular materials were soluble in common organic volatile solvents, and their structures were investigated by NMR, FT-IR and MALDI-TOF spectroscopies. Thermal analysis showed a correlation between the thermal properties of these derivatives and the benzylation degree. The surface properties of the thin films based on the benzylated β-CDs were characterized by contact angle measurements and atomic force microscopy (AFM). These organic materials were investigated as sensitive layers, deposited on quartz crystal microbalance (QCM) gravimetric transducer, for humidity sensor at room temperature. The results showed that the performances of the prepared sensors are greatly influenced by the benzylation degree of β-CD. The partially modified β-CD (DS=1) shows linear response with best sensitivity, good reproducibility, low hysteresis, fast response time (15s) and recovery time (17s) at higher relative humidity levels (RH) between 11% and 98% in room temperature.

Keywords: β-cyclodextrin, green synthesis, humidity sensor, quartz crystal microbalance

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652 Designed Purine Molecules and in-silico Evaluation of Aurora Kinase Inhibition in Breast Cancer

Authors: Pooja Kumari, Anandkumar Tengli

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Aurora kinase enzyme, a protein on overexpression, leads to metastasis and is extremely important for women’s health in terms of prevention or treatment. While creating a targeted technique, the aim of the work is to design purine molecules that inhibit in aurora kinase enzyme and helps to suppress breast cancer. Purine molecules attached to an amino acid in DNA block protein synthesis or halt the replication and metastasis caused by the aurora kinase enzyme. Various protein related to the overexpression of aurora protein was docked with purine molecule using Biovia Drug Discovery, the perpetual software. Various parameters like X-ray crystallographic structure, presence of ligand, Ramachandran plot, resolution, etc., were taken into consideration for selecting the target protein. A higher negative binding scored molecule has been taken for simulation studies. According to the available research and computational analyses, purine compounds may be powerful enough to demonstrate a greater affinity for the aurora target. Despite being clinically effective now, purines were originally meant to fight breast cancer by inhibiting the aurora kinase enzyme. In in-silico studies, it is observed that purine compounds have a moderate to high potency compared to other molecules, and our research into the literature revealed that purine molecules have a lower risk of side effects. The research involves the design, synthesis, and identification of active purine molecules against breast cancer. Purines are structurally similar to the normal metabolites of adenine and guanine; hence interfere/compete with protein synthesis and suppress the abnormal proliferation of cells/tissues. As a result, purine target metastasis cells and stop the growth of kinase; purine derivatives bind with DNA and aurora protein which may stop the growth of protein or inhibits replication and stop metastasis of overexpressed aurora kinase enzyme.

Keywords: aurora kinases, in silico studies, medicinal chemistry, combination therapies, chronic cancer, clinical translation

Procedia PDF Downloads 71
651 Characterization and Modification of the Optical Properties of Zirconia Ceramics for Aesthetic Dental Restorations

Authors: R. A. Shahmiri, O. Standard, J. Hart, C. C. Sorrell

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Yttrium stabilized tetragonal zirconium polycrystalline (Y-TZP) has been used as a dental biomaterial. The strength and toughness of zirconia can be accounted for by its toughening mechanisms, such as crack deflection, zone shielding, contact shielding, and crack bridging. Prevention of crack propagation is of critical importance in high-fatigue situations, such as those encountered in mastication and para-function. However, the poor translucency of Y-TZP means that it may not meet the aesthetic requirements due to its white/grey appearance in polycrystalline form. To improve optical property of the Zirconia, precise evaluation of its refractive index is of significance. Zirconia`s optical properties need to be studied more in depth. Number of studies assumed, scattered light is isotropically distributed over all angles from biological media when defining optical parameters. Nevertheless, optical behaviour of real biological material depends on angular scattering of light by anisotropy material. Therefore, the average cosine of the scattering angle (which represent recovery phase function in the scattering angular distribution) usually characterized by anisotropy material. It has been identified that yttrium anti-sites present in the space charge layer have no significant role in the absorption of light in the visible range. Addition of cation dopant to polycrystalline zirconia results in segregate to grain boundaries and grain growth. Intrinsic and extrinsic properties of ZrO2 and their effect on optical properties need to be investigated. Intrinsic properties such as chemical composition, defect structure (oxygen vacancy), phase configuration (porosity, second phase) and distribution of phase need to be studied to comprehend their effect on refraction index, absorption/reflection and scattering. Extrinsic properties such as surface structure, thickness, underlying tooth structure, cement layer (type, thickness), and light source (natural, curing, artificial) of ZrO2 need to be studied to understand their effect on colour and translucency of material. This research reviewed effect of stabilization of tetragonal zirconia on optical property of zirconia for dental application.

Keywords: optical properties, zirconia dental biomaterial, chemical composition, phase composition

Procedia PDF Downloads 384
650 Investigation of Electrochemical, Morphological, Rheological and Mechanical Properties of Nano-Layered Graphene/Zinc Nanoparticles Incorporated Cold Galvanizing Compound at Reduced Pigment Volume Concentration

Authors: Muhammad Abid

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The ultimate goal of this research was to produce a cold galvanizing compound (CGC) at reduced pigment volume concentration (PVC) to protect metallic structures from corrosion. The influence of the partial replacement of Zn dust by nano-layered graphene (NGr) and Zn metal nanoparticles on the electrochemical, morphological, rheological, and mechanical properties of CGC was investigated. EIS was used to explore the electrochemical nature of coatings. The EIS results revealed that the partial replacement of Zn by NGr and Zn nanoparticles enhanced the cathodic protection at reduced PVC (4:1) by improving the electrical contact between the Zn particles and the metal substrate. The Tafel scan was conducted to support the cathodic behaviour of the coatings. The sample formulated solely with Zn at PVC 4:1 was found to be dominated in physical barrier characteristics over cathodic protection. By increasing the concentration of NGr in the formulation, the corrosion potential shifted towards a more negative side. The coating with 1.5% NGr showed the highest galvanic action at reduced PVC. FE-SEM confirmed the interconnected network of conducting particles. The coating without NGr and Zn nanoparticles at PVC 4:1 showed significant gaps between the Zn dust particles. The novelty was evidenced when micrographs showed the consistent distribution of NGr and Zn nanoparticles all over the surface, which acted as a bridge between spherical Zn particles and provided cathodic protection at a reduced PVC. The layered structure of graphene also improved the physical shielding effect of the coatings, which limited the diffusion of electrolytes and corrosion products (oxides/hydroxides) into the coatings, which was reflected by the salt spray test. The rheological properties of coatings showed good liquid/fluid properties. All the coatings showed excellent adhesion but had different strength values. A real-time scratch resistance assessment showed all the coatings had good scratch resistance.

Keywords: protective coatings, anti-corrosion, galvanization, graphene, nanomaterials, polymers

Procedia PDF Downloads 75
649 Study of the Relationship between the Civil Engineering Parameters and the Floating of Buoy Model Which Made from Expanded Polystyrene-Mortar

Authors: Panarat Saengpanya

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There were five objectives in this study including the study of housing type with water environment, the physical and mechanical properties of the buoy material, the mechanical properties of the buoy models, the floating of the buoy models and the relationship between the civil engineering parameters and the floating of the buoy. The buoy examples made from Expanded Polystyrene (EPS) covered by 5 mm thickness of mortar with the equal thickness on each side. Specimens are 0.05 m cubes tested at a displacement rate of 0.005 m/min. The existing test method used to assess the parameters relationship is ASTM C 109 to provide comparative results. The results found that the three type of housing with water environment were Stilt Houses, Boat House, and Floating House. EPS is a lightweight material that has been used in engineering applications since at least the 1950s. Its density is about a hundredth of that of mortar, while the mortar strength was found 72 times of EPS. One of the advantage of composite is that two or more materials could be combined to take advantage of the good characteristics of each of the material. The strength of the buoy influenced by mortar while the floating influenced by EPS. Results showed the buoy example compressed under loading. The Stress-Strain curve showed the high secant modulus before reached the peak value. The failure occurred within 10% strain then the strength reduces while the strain was continuing. It was observed that the failure strength reduced by increasing the total volume of examples. For the buoy examples with same area, an increase of the failure strength is found when the high dimension is increased. The results showed the relationship between five parameters including the floating level, the bearing capacity, the volume, the high dimension and the unit weight. The study found increases in high of buoy lead to corresponding decreases in both modulus and compressive strength. The total volume and the unit weight had relationship with the bearing capacity of the buoy.

Keywords: floating house, buoy, floating structure, EPS

Procedia PDF Downloads 127
648 The Psychosis Prodrome: Biomarkers of the Glutamatergic System and Their Potential Role in Prediction and Treatment

Authors: Peter David Reiss

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The concept of the psychosis prodrome has allowed for the identification of adolescent and young adult patients who have a significantly elevated risk of developing schizophrenia spectrum disorders. A number of different interventions have been tested in order to prevent or delay progression of symptoms. To date, there has been no consistent meta-analytical evidence to support efficacy of antipsychotic treatment for patients in the prodromal state, and their use remains therefore inconclusive. Although antipsychotics may manage symptoms transiently, they have not been found to prevent or delay onset of psychotic disorders. Furthermore, pharmacological intervention in high-risk individuals remains controversial, because of the antipsychotic side effect profile in a population in which only about 20 to 35 percent will eventually convert to psychosis over a two-year period, with even after two years conversion rates not exceeding 30 to 40 percent. This general estimate is additionally problematic, in that it ignores the fact that there is significant variation in individual risk among clinical high-risk cases. The current lack of reliable tests for at-risk patients makes it difficult to justify individual treatment decisions. Preventive treatment should ideally be dictated by an individual’s risk while minimizing potentially harmful medication exposure. This requires more accurate predictive assessments by using valid and accessible prognostic markers. The following will compare prediction and risk modification potential of behavioral biomarkers such as disturbances of basic sense of self and emotion awareness, neurocognitive biomarkers such as attention, working and declarative memory, and neurophysiological biomarkers such as glutamatergic abnormalities and NMDA receptor dysfunction. Identification of robust biomarkers could therefore not only provide more reliable means of psychosis prediction, but also help test and develop new clinical interventions targeted at the prodromal state.

Keywords: at-risk mental state, biomarkers, glutamatergic system, NMDA receptor, psychosis prodrome, schizophrenia

Procedia PDF Downloads 180
647 Tripeptide Inhibitor: The Simplest Aminogenic PEGylated Drug against Amyloid Beta Peptide Fibrillation

Authors: Sutapa Som Chaudhury, Chitrangada Das Mukhopadhyay

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Alzheimer’s disease is a well-known form of dementia since its discovery in 1906. Current Food and Drug Administration approved medications e.g. cholinesterase inhibitors, memantine offer modest symptomatic relief but do not play any role in disease modification or recovery. In last three decades many small molecules, chaperons, synthetic peptides, partial β-secretase enzyme blocker have been tested for the development of a drug against Alzheimer though did not pass the 3rd clinical phase trials. Here in this study, we designed a PEGylated, aminogenic, tripeptidic polymer with two different molecular weights based on the aggregation prone amino acid sequence 17-20 in amyloid beta (Aβ) 1-42. Being conjugated with poly-ethylene glycol (PEG) which self-assembles into hydrophilic nanoparticles, these PEGylated tripeptides constitute a very good drug delivery system crossing the blood brain barrier while the peptide remains protected from proteolytic degradation and non-specific protein interactions. Moreover, being completely aminogenic they would not raise any side effects. These peptide inhibitors were evaluated for their effectiveness against Aβ42 fibrillation at an early stage of oligomer to fibril formation as well as preformed fibril clearance via Thioflavin T (ThT) assay, dynamic light scattering analyses, atomic force microscopy and scanning electron microscopy. The inhibitors were proved to be safe at a higher concentration of 20µM by the reduction assay of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) dye. Moreover, SHSY5Y neuroblastoma cells have shown a greater survivability when treated with the inhibitors following Aβ42 fibril and oligomer treatment as compared with the control Aβ42 fibril and/or oligomer treated neuroblastoma cells. These make the peptidic inhibitors a promising compound in the aspect of the discovery of alternative medication for Alzheimer’s disease.

Keywords: Alzheimer’s disease, alternative medication, amyloid beta, PEGylated peptide

Procedia PDF Downloads 195
646 Screening of Some Saudi Plants for Their Alleviating Effect on the Exaggerated Vasoconstriction in Metabolic Syndrome

Authors: Hossam M. Abdallah, Ali M. El-Halawany, Gamal A. Mohamed, Khalid Z. Alshali, Zainy M. Banjar, Hany A. El-Bassossy

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Hypertension and vascular dysfunction are major components and complications of many diseases like metabolic syndrome. In addition, vascular dysfunction is considered the initial step in diabetic atherosclerosis, the main etiology for mortality and a great percent of morbidity in diabetic patients. In spite of the significant developments in antidiabetic therapy, diabetic complications, particularly seen in long-term diabetes, continue to be seriously deleterious. Herbal drugs are prescribed widely in treatment of different aliment because of their effectiveness, fewer side effects and relatively low cost. Nine plants belong to five different families grown in Kingdom of Saudi Arabia were evaluated for their effect on exaggerated vasoconstriction and impaired relaxation in aortae isolated from metabolic syndrome rats. The aerial parts of Onopordum ambiguum Fresen. (OA), Astragalus abyssinicus Steud. (AA), Pulicaria Arabica Cass. (PA), Echinops sheilae Kit Tan (ES), Aizoon canariense L. (AC), Cleome viscosa L. (CV), Chrozophora oblongifolia (Delile) A.Juss. ex Spreng (CO), Centaurea pseudosinaica Mouterde (CP) and Tephrosia nubica Baker (TN) were dried and extracted with methanol. The effect of thirty minute incubation with the total extracts (10-330 µg/ml) or their fractions on the exaggerated vasoconstriction response to phenylephrine (10nM to 10microM) and impaired vasodilation to acetylcholine (10-330 µg /ml) of aortae isolated from metabolic syndrome animals was studied. Incubating aortae isolated from metabolic syndrome animals with total methanol extract of OA, AA, PA, AC, CV, and TN at concentrations (10-330 microgram/ml) in the organ bath led to concentration dependent alleviation of exaggerated vasoconstriction response to phenylephrine without having beneficial effect on impaired vasodilation to acetylcholine. In conclusion, addition of OA, AA, PA, AC, CV and TN to the standard therapies may provide superior means to alleviate the associated vascular complications.

Keywords: vascular dysfunction, exaggerated vasoconstriction, metabolic syndrome, Saudi plants

Procedia PDF Downloads 264
645 A Review of the Effects of Exercise in Preventing Migraine Headaches

Authors: Afsaneh Soltani, Zahra Mohajer

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Migraine is one of the most common chronic neurological diseases. Migraines affect different aspects of life. Severe migraine headaches lead to dysfunction, a reduced presence at work, and decreased ability to think and make decisions. Non-pharmacological treatments play a very important role in controlling and preventing migraine headaches. A healthy lifestyle helps control migraine headaches. Migraine headaches can be reduced by following these steps: Avoiding stress, eating regularly and avoiding hunger and thirst, avoiding stimulants such as chocolate, caffeine, and cigarettes, following a regular bedtime routine, or avoiding sleep deprivation. Exercise a lot, and do regular exercise (and prevent obesity). Non-pharmacological treatment is especially important in pregnant women and children because in these cases, medical treatments are not preferred due to the many side effects. Exercise is one of the most effective and uncomplicated non-pharmacological alternatives in the treatment of migraine headaches. Exercising for episodic migraines is a safe, effective, and promising complementary treatment option. Numerous studies have shown that aerobic exercise reduces the severity and duration of migraine headaches. Effective aerobic exercise includes cycling and brisk walking. Exercise improves the quality of life and reduces the use of medication in people with migraines. Patients who exercise have fewer migraine days, resulting in better personal, social, and occupational performance. Several studies have shown that pain intensity and frequency in patients who exercise regularly decreased significantly after exercise compared to controls who did not exercise. According to a study, regular exercise reduces the levels of interleukins, especially IL-12P70, which reduces anxiety and reduces the number of days of migraine in patients. An article has shown that endurance exercise reduces the number of migraine days and also increases cerebrovascular health in migraine patients. According to studies, the minimum duration of exercise to achieve a positive effect of exercise in patients with migraine is 3 months (12 weeks) and 40 minutes three times a week.

Keywords: exercise, headache, migraine, physical activity

Procedia PDF Downloads 91
644 Management of Severe Asthma with Omalizumab in United Arab Emirates

Authors: Shanza Akram, Samir Salah, Imran Saleem, Jassim Abdou, Ashraf Al Zaabi

Abstract:

Estimated prevalence of asthma in UAE is around 10% (900,000 people). Patients with persistent symptoms despite using high dose ICS plus a second controller +/- Oral steroids are considered to have severe asthma. Omalizumab (Xolair) is an anti-IgE monoclonal antibody approved as add-on therapy for severe allergic asthma. The objective of our study was to obtain baseline characteristics of our local cohort, to determine the efficacy of omalizumab based on clinical outcomes pre and post 52 weeks of treatment and to assess safety and tolerability. Medical records of patients receiving omalizumab therapy for asthma at Zayed Military Hospital, Abu Dhabi were retrospectively reviewed. Patients fulfilling the criteria for severe allergic asthma as per GINA guidelines were included. Asthma control over 12 months pre and post omalizumab were analyzed by taking into account the number of exacerbations, hospitalizations, maintenance of medication dosages, the need for reliever therapy and PFT’s. 21 patients (5 females) with mean age 41 years were included. The mean duration of therapy was 22 months. 19 (91%) patients had Allergic Rhinitis/Sinusitis. Mean serum total IgE level was 648 IU/ml (65-1859). 11 (52%) patients were on oral maintenance steroids pre-treatment. 7 patients managed to stop steroids on treatment while 4 were able to decrease the dosage. Mean exacerbation rate decreased from 5 per year pre-treatment to 1.36 while on treatment. The number of hospitalizations decreased from a mean of 2 per year to 0.9 per year. Reliever inhaler usage decreased from mean of 40 to 15 puffs per week.2 patients discontinued therapy, 1 due to lack of benefit (2 doses) and 2nd due to severe persistent side effects. Patient compliance was poor in some cases. Treatment with omalizumab reduced the number of exacerbations, hospitalizations, maintenance and reliever medications, and is generally well tolerated. Our results show that there is room for improved documentation in terms of symptom recording and use of rescue medication at our institution. There is also need for better patient education and counseling in order to improve compliance.

Keywords: asthma, exacerbations, omalizumab, IgE

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643 Eco-Friendly Silicone/Graphene-Based Nanocomposites as Superhydrophobic Antifouling Coatings

Authors: Mohamed S. Selim, Nesreen A. Fatthallah, Shimaa A. Higazy, Hekmat R. Madian, Sherif A. El-Safty, Mohamed A. Shenashen

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After the 2003 prohibition on employing TBT-based antifouling coatings, polysiloxane antifouling nano-coatings have gained in popularity as environmentally friendly and cost-effective replacements. A series of non-toxic polydimethylsiloxane nanocomposites filled with nanosheets of graphene oxide (GO) decorated with magnetite nanospheres (GO-Fe₃O₄ nanospheres) were developed and cured via a catalytic hydrosilation method. Various GO-Fe₃O₄ hybrid concentrations were mixed with the silicone resin via solution casting technique to evaluate the structure–property connection. To generate GO nanosheets, a modified Hummers method was applied. A simple co-precipitation method was used to make spherical magnetite particles under inert nitrogen. Hybrid GO-Fe₃O₄ composite fillers were developed by a simple ultrasonication method. Superhydrophobic PDMS/GO-Fe₃O₄ nanocomposite surface with a micro/nano-roughness, reduced surface-free energy (SFE), high fouling release (FR) efficiency was achieved. The physical, mechanical, and anticorrosive features of the virgin and GO-Fe₃O₄ filled nanocomposites were investigated. The synergistic effects of GO-Fe₃O4 hybrid's well-dispersion on the water-repellency and surface topological roughness of the PDMS/GO-Fe₃O₄ nanopaints were extensively studied. The addition of the GO-Fe₃O₄ hybrid fillers till 1 wt.% could increase the coating's water contact angle (158°±2°), minimize its SFE to 12.06 mN/m, develop outstanding micro/nano-roughness, and improve its bulk mechanical and anticorrosion properties. Several microorganisms were employed for examining the fouling-resistance of the coated specimens for 1 month. Silicone coatings filled with 1 wt.% GO-Fe₃O₄ nanofiller showed the least biodegradability% among all the tested microorganisms. Whereas GO-Fe₃O4 with 5 wt.% nanofiller possessed the highest biodegradability% potency by all the microorganisms. We successfully developed non-toxic and low cost nanostructured FR composite coating with high antifouling-resistance, reproducible superhydrophobic character, and enhanced service-time for maritime navigation.

Keywords: silicone antifouling, environmentally friendly, nanocomposites, nanofillers, fouling repellency, hydrophobicity

Procedia PDF Downloads 89