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Fabrication and Characterization on Physico-Mechanical and Structural Properties of Sawdust Reinforced Acrylonitrile Butadiene Styrene (ABS) Composites

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Materials Sciences and Applications 2020年第9期11卷 644-658页

作者： Budrun Neher Nabila Tasnim Nova Rakib Hossain M. A. Gafur Farid ahmed Department of Physics Jahangirnagar University Dhaka Bangladesh Department of Physics Bangabandhu Sheikh Mujibur Rahman Science & Technology University Gopalganj Bangladesh PP and PDC Bangladesh Council of Scientific and Industrial Research Dhaka Bangladesh

The sawdust reinforced Acrylonitrile Butadiene Styrene (ABS) composites were prepared by using hot press molding machine for five different wt% (0%, 5%, 10%, 15% and 20%) at 180°C temperature and 50 KN load. Sawdust was collected from local saw mill of Savar, Dhaka, Bangladesh and ABS polymer was collected from local market of Dhaka, Bangladesh. In this study, different properties of composites like physical (bulk density and water absorption), mechanical (tensile properties and hardness) and structural (Fourier Transform Infrared Spectroscopy) properties were studied. The bulk density of composites was not altered consistently and it gave greater value for 5% and 20% composites. The water absorption enhanced for all composites with the accumulation of fiber content and soaking time. The reduction of tensile strength and Leeb’s rebound hardness of the composites were observed with the increase of the fiber content in all compositions. Maximum (%) of elongation was found for 5% composite, and then it gradually decreased;however, elastic modulus increased with the increased of fiber content in composites. Fourier Transform Infrared (FTIR) spectroscopy study was done for structural characterization. It was found that there was a new bond (C≡C) stretching formed for 20% composite;moreover, C-H rocking for 0% composite was broken for all other composites after the addition of sawdust in ABS polymer matrix.

关键词： Sawdust-ABS Composite Hot Press Molding Machine Tensile Strength Leeb’s Rebound Hardness FTIR Spectroscopy

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Clinical Isolates of Staphylococcus aureus Show Variation in β-Lactamase Production and Are More Susceptible to Antibiotics Conjugated with β-Lactamase Inhibitors

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Open Journal of Medical Microbiology 2016年第4期6卷 143-149页

作者： Uzal Umar Umar ahmed Faruk Damoroem M. Tanko Mohammed B. Yerima Department for Biological Sciences Abubakar Tafawa Balewa University Bauchi Nigeria Department of Microbiology Federal University Dutse Dutse Nigeria

β-Lactam antibiotics are a cornerstone in the treatment of bacterial infections on account of its high therapeutic index and selective toxicity—they act by inhibiting the biosynthesis of peptidoglycan, a key component in bacterial cell wall. Ninety (90) clinical specimens obtained from the microbiology unit Specialist Hospital Bauchi were screened for S. aureus, positive isolates were examined for β-Lactamase expression by using two Penicillin G concentrations (5000 IU/ml and 25,000 IU/ml) in acidometric agar technique with phenol red as indicator, and the susceptibility pattern of the isolates to β-Lactam antibiotics was also determined. S. aureus prevalence of 31% (28/90) was obtained, of which 96% (27/28) of strains were β-Lactamase positive in the standard test, while 63% (17/27) were able to hydrolyze penicillin G concentration of 25,000 IU/ml (5X the concentration in the standard test), and a strain was found to be β-Lactamase negative. The resistance to five β-Lactams, ampicillin, cephalexin, amoxicillin, cloxacillin and flucloxaillin, were 100%, 96%, 89%, 74% and 56% respectively. When ampicillin and amoxicillin were conjugated to β-Lactamase inhibitors sulbactam and clavulanic acid respectively the resistance to ampicillin decreased to 21% and to amoxicillin to 15%. The antibiotic susceptibility profile revealed β-Lactamase elaboration to be the major mechanism of resistance to the β-Lactams. β-Lactam utilization as therapeutic option would thus require the search for sensitive irreversible β-Lactamase inhibitors for the β-Lactamase enzymes or agents to block the release of β-Lactamase by strains.

关键词： β-Lactamase Peptidoglycan Transpeptidation Haemolysis Resistance Antibiotics

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HER2-Specific Vaccines for HER2-Positive Breast Cancer Immunotherapy

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World Journal of Vaccines 2015年第2期5卷 106-128页

作者： Maxwell Omabe Shahid ahmed Amer Sami Yufeng Xie Min Tao Jim Xiang Cancer Research Cluster Saskatchewan Cancer Agency Saskatoon Canada Department of Oncology University of Saskatchewan Saskatoon Canada Department of Oncology The first Affiliated Hospital Soo-Chow University Suzhou China

Anti-human epidermal growth factor receptor-2 (HER2) immunization can be elicited by vaccination with DNA encoding the extra- or intra-cellular domain (ECD or ICD) of HER2, naked or encap-sulated in viral vectors. HER2-peptides derived from ECD or ICD of HER2, and HER2-pulsed dendritic cells (DCs) or engineered DCs expressing HER2, respectively. We performed a computer- based literature search which includes but is not limited to the following keywords: breast cancer, immunotherapy, HER2-peptide vaccine, HER2-DNA vaccine, HER-DC vaccine, HER2 vaccine, and HER2/neu, in PubMed, Medline, EMBO and Google Scholar;data from recently reported clinical trials were also included. Drawing upon this synthesis of literature, this work summarizes the de-velopment and current trend in experimental and clinical investigations in HER2-positive breast cancer using HER2-specific vaccine and immunotherapy, focusing especially on: (i) DNA-;(ii) peptide-;and (iii) DC-based vaccines. It addresses interventions that have been applied to overcome immunotolerance thereby to improve treatment outcomes. These include blocking the inhibitory cytotoxic T lymphocyte-associated protein-4 (CTLA-4), which is expressed at high levels by regulatory T (Treg) cells, or complete Treg depletion to improve T-cell activation. Moreover, modulatory interventions can provide further improvement in the efficacy of HER2-specific vaccine. The interventions include the use of immunogenic adjuvants such as cytokines interleukin-12 (IL-12), tumor necrosis factor (TNF)-α and granulocyte-macrophage colony-stimulating factor (GM-CSF), the use of Toll-like receptor (TLR) ligands and tetanus toxin’s universal epitopes such as the CD4+ help T (Th)-epitope P30, and the use of either chimeric or heterogenous xenogeneic HER2. Combining active HER2-vaccination with adoptive trastuzumab antibody immunotherapy is likely to increase the effectiveness of each approach alone. The development of effective HER2-vaccines for breast

关键词： HER2 Breast Cancer DNA Peptide Dendritic Cell Vaccine

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GSTM1,GSTT1,GSTP1 and CYP1A1 genetic polymorphisms and susceptibility to esophageal cancer in a French population:Different pattern of squamous cell carcinoma and adenocarcinoma

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World Journal of Gastroenterology 2004年第23期10卷 3389-3393页

作者： ahmed Abbas Karine Delvinquière Mathilde Lechevrel Pierre Lebailly Pascal Gauduchon Guy Launoy Fran ois Sichel GRECAN-EA1772 UFR des Sciences Pharmaceutiques Université de Caen Basse-Normandie et Centre Francois BaclesseAvenue du Général Harris14076 Caen cedex 05France GRECAN-EA1772 Université de Caen Basse-Normandie et Registre des Tumeurs Digestives du Calvados UFR de MédecineAvenue de la C te de Nacre14032 Caen cedexFrance

AIM:To evaluate the association between CYP1A1 and GSTs genetic polymorphisms and susceptibility to esophageal squamous cell carcinoma(SCC)and esophageal adenocarcinoma(ADC)in a high risk area of northwest of France. METHODS:A case-control study was conducted to investigate the genetic polymorphisms of these enzymes (CYPIAI*2C and GSTP1 exon 7 Val alleles,GSTMI*2/*2 and GSTTl *2/*2 null genotypes).A total of 79 esophageal cancer cases and 130 controls were recruited. RESULTS:GSTMI*2/*2 and CYPIAI*IA/*2C genotype frequencies were higher among squamous cell carcinomas at a level dose to statistical significance(OR =1.83,95% CI 0.88-3.83,P=0.11;OR=3.03,95% CI 0.93-9.90,P=0.07, respectively).For GSTP1 polymorphism,no difference was found between controls and cases,whatever their histological *** frequency of GSTT1 deletion was observed in ADC group compared to controls with a statistically significant difference(OR=13.31,95% CI 1.66-106.92,P<0.01). CONCLUSION:In SCC,our results are consistent with the strong association of this kind of tumour with tobacco *** ADC,our results suggest 3 distinct hypotheses: (1)activation of exogenous procarcinogens,such as small halogenated compounds by GSTT1;(2)contribution of GSTT1 to the inflammatory response of esophageal mucosa,which is known to be a strong risk factor for ADC, possibly through leukotriene synthesis;(3)higher sensitivity to the inflammatory process associated with intracellular depletion of glutathione.

关键词： Acyltransferases Adenocarcinoma Adult Aged Aged, 80 and over Carcinoma, Squamous Cell Case-Control Studies Cytochrome P-450 CYP1A1 Esophageal Neoplasms Female France Genetic Predisposition to Disease Genotype Glutathione Transferase Humans Male Middle Aged Polymorphism, Genetic Research Support, Non-U.S. Gov't Risk Factors

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Knowledge Attitude and Practice about Water-Pipe Smoking among Saudi Population

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Journal of Biosciences and Medicines 2020年第3期8卷 58-72页

作者： Reema Fahad Abdulrahman Alnumair Amal Hussain Mohammed Ali Hussam ahmed Mohammed Alghamdi Department of Medical Laboratories College of Applied Medical Sciences Qassim University Qassim Kingdom of Saudi Arabia

Water pipe smoking has been practiced extensively for about 400 years. Water pipe smoking is common in the Saudi Arabia. Water-pipe smoking exposes smokers to high levels of tobacco and toxins. An observational and cross-sectional survey carried among 1170 participants to determine the knowledge, attitude, and practice about water-pipe smoking among Saudi population. Data was collected and obtained by the online questionnaire that has been created in Google form and then published in different social media platforms over a period from September 2019 to November 2019. The data were entered in Excel and analyzed in EpiInfo7 statistical software to get descriptive statistics. Results: About 70% were females and 30% male, 43% of them are university students with 83% in the age group of the 18 - 25 high participants. Low knowledge of Carbon monoxide poisoning effects = 78%, While 54% of the participants showed low knowledge about infectious disease transmitted by water-pipe. The Knowledge about water pipe contents and carbon monoxide poisoning was low. Further efforts will be necessary to increase the level of awareness among participants in Saudi Arabia regarding water pipe contents and carbon monoxide poisoning.

关键词： Knowledge Attitude Practice Water-Pipe Smoking Saudi

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Evaluating Discharge Capacity of Major Chara’s of Sylhet City Using GIS

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Journal of Water Resource and Protection 2018年第2期10卷 167-181页

作者： Gulam Md. Munna Jahir Bin Alam Jobayer ahmed Abdullah Al Mamun Department of Civil and Environmental Engineering Shahjalal University of Science and Technology (SUST) Kumargaon Sylhet-3114 Bangladesh

Heavy rainfall is one of the most frequent and widespread severe weather hazards that affect Sylhet city. In Sylhet, nine natural channels locally called “chara” are mainly responsible for the drainage of heavy rainfall to the Surma River. The present condition of this natural drainage is not feasible due to the unplanned land development and manipulation by people. So water logging is a common scenario of Sylhet city. Many parts of Sylhet city are experiencing the severe inundation problem due to heavy rainfall. Time series analysis of rainfall data (1974-2015) is important for knowing and predicting of rainfall variation. Mann-Kendall analysis showed no trend for monthly and yearly rainfall data. The rainfall intensity of Sylhet is higher than other districts of Bangladesh. In this study, IDF (Intensity Duration Frequency) curve has been developed that is commonly used in engineering planning and design. By using IDF curve, ArcGIS software, DEM map, and normal discharge, maximum discharge for a different point of Mongoli chara and Bolramer chara has been calculated (for 25 years return period). Discharge through Mongoli chara and Bolramer chara has been represented in ArcMap using ordinary kriging. To keep the catchment of those chara free from inundation and water logging problem, this calculated discharge needed to be managed.

关键词： ArcGIS Canal Chi-Square Gamble Distribution IDF Curve Mann-Kendall Rainfall

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Botulinum Toxin Type A Satisfaction in Different Neurological Disorders

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Neuroscience & Medicine 2022年第1期13卷 1-16页

作者： Jasem Yousef Al-Hashel Doaa Youssry Soliman Ismail Ibrahim Ismail Samar Farouk ahmed Department of Neurology Ibn Sina Hospital Kuwait City Kuwait Department of Medicine Faculty of Medicine Health Sciences Centre Kuwait University Kuwait City Kuwait Department of Neurology Cairo University Cairo Egypt Department of Neuropsychiatry Faculty of Medicine Minia University Minia Egypt

Background: The botulinum toxin type A (BoNT-A) is used in a wide range of neurological diseases. We aimed to study the overall patients/caregivers’ satisfaction with BoNT-A treatment in different neurological conditions. Methods: Prospective study included patients who had received at least two BoNT-A treatment sessions. They were asked to rate overall treatment satisfaction at the peak of treatment effect on a 1 to 10 scale (1 = not at all satisfied;10 = fully satisfied). Subjects with a rating of 1to3 were classified as not at all satisfied, those with a rating of 4 to7 as somewhat satisfied, and those with a rating of 8 to10 as very satisfied. Treatment satisfaction questionnaire for medicine (TSQM) was assessed at the end of observational period. Quality of life QOL was assessed before BoNT-A treatment and at the last visit. Results: The study was conducted from first April 2014 to August 2021. 548 patients were identified with mean age 43.66 ± 14.50. Most of participants 389 (71%) were female. At the end of observational period, the mean satisfaction was 7.28 ± 1.78. There was a highly significant difference (P P P = 0.001). Conclusion: Satisfaction with BoNT-A therapy for different neurological disorders is overall good. The highest patient satisfaction was observed with primary focal HH, and the least satisfaction was observed in writer’s cramp. BoNT-A therapy improved QOL.

关键词： Botulinum Toxin Type A Satisfaction Headache Dystonia Movement Disorders Hyperhidrosis

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Measuring Audit Firms＇ Intellectual Capital as a Determinant of Audit Quality： A Suggested Model

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Journal of Modern Accounting and Auditing 2014年第1期10卷 59-79页

作者： Amr N. Abdelrhman Khaled Z. Labib ahmed F. Elbayoumi Cairo University Cairo Egypt Cairo University Cairo EgyptThe American University in Cairo Cairo Egypt

The intellectual capital is a main source of competing advantage. Many studies developed measure（s） of intellectual capital of industrial and service firms. Few studies have tried to develop a reliable measure of intellectual capital in audit firms. This study extends the current models to provide more insight into the role of intellectual capital in audit firms. The aim of this study is to develop a quantitative model to measure audit firms＇ intellectual capital. The suggested model can be used to explore the relationship between the intellectual capital in audit firms and audit quality. The model combines the main components of intellectual capital （human capital, structural capital, and relational capital）. The suggested model provides a tool that may help to better manage the intellectual capital in audit firms. As this is a theoretical study, a number of hypotheses are presented for testing in the future.

关键词： intellectual capital human capital structural capital relational capital audit quality audit firms

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The Gravitomagnetic and Field Magnetic Centrifugal Force Using Force and Four-Dimensional Potential Concepts

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Natural Science 2022年第3期14卷 125-132页

作者： Mohamed Yahia Shirgawi Zoalnoon ahmed Abeid Allah Saad Mubarak Dirar Abd-Alla Yagoub Department of Physics Faculty of Art and Science at Al Muznab Al Qassim University Buraydah Saudi Arabia Department of Physics Faculty of Arts and Sciences at Dhahran Aljanoub King Khalid University Abha Saudi Arabia Department of Physics Faculty of Science Sudan University of Science and Technology Khartoum Sudan

Unification of fundamental forces is the dream of physics. Nevertheless, unfortunately gravitational force operators to be isolated in its geometrical content from other forces. This encourages some researchers to propose the so-called gravimagnetic field to unify gravity with other forces and to explain some cosmological problems at the early universe. This motivates to construct a new model to confirm the existence of gravitomagnetic and a corresponding magnetic field associated with any field. Using the formal Newton definition of force and considering the magnetic force to be related to the time varying mass, the magnetic force is shown to be equal to the centrifugal force. This equality is typical when treating a particle as string. Using also the definition of force in terms of potential and electric force only, energy is shown to be conserved. The Newton force can be defined also in terms of four-dimensional potential with the time varying part related to the magnetic potential. When the particle is treated as a string, energy conservation holds, while for ordinary particle, the Lagrangian is conserved. The energy conservation holds for special relativity also for energy per unit mass. The definition of acceleration for forces that obeys inverse square law shows also the magnetic force is equal to the centrifugal force.

关键词： Gravitomagnetic Force Magnetic Force Newton Force Special Relativity Centrifugal Force Energy Lagrangian

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First-Order Studies of Nanometric Biferroic

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World Journal of Condensed Matter Physics 2012年第2期2卷 66-74页

作者： M. A. ahmed U. Seddik N. G. Imam Materials Science Lab.(1) Physics Department Faculty of Science Cairo University Giza Egypt Physics Department Nuclear Research Center Atomic Energy Authority Cairo Egypt

Magnetoelectric biferroic nanocomposite with composition 0.5Ni0.5Zn0.5Fe2O4 + 0.5BaTiO3 was synthesized by ceramic technique. The structural and electrical characterizations of the investigated nanocomposite are discussed and reported. The formation of nanosized composite with two separate phases was confirmed by X-ray diffraction, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The variation of dielectric constant (ε'), dielectric loss factor (ε') and the ac conductivity (σac) of 0.5Ni0.5Zn0.5Fe2O4 + 0.5BaTiO3 was investigated as a function of both frequency and temperature. Thermal hysteresis (first-order transition) was obtained during heating (300 - 830 K) and cooling runs (830 - 300 K). The exact transition temperature and the amount area of the thermal hysteresis depend on applied ac electric field. The delay (lagging) time between heating and cooling processes was esti-mated from the hysteresis loop area versus frequency. The conduction mechanism in the investigated samples was explained according to different models. This study enhances the use of this prepared system in memory applications.

关键词： Biferroic Nanocomposite Nickel-Zinc Ferrite Barium Titanate Dielectric Hysteresis First-Order Transition

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