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Interlaminar Fracture Toughness of Epoxy Glass Fiber Fly Ash Laminate Composite

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Materials Sciences and Applications 2014年第4期5卷 231-244页

作者： ajit Bhandakkar Niraj kumar R. C. Prasad Shankar M. L. Sastry Department of Metallurgical Engineering and Materials Science Indian Institute of Technology Bombay Mumbai India Mechanical Aerospace and Structural Engineering Washington University in St. Louis Saint Louis USA

Epoxy glass fiber laminate composite (PMCs) are finding ever increasing applications in aerospace and automobile industries due to its high strength to weight ratio and resistance to aqueous environment. Additions of particulate reinforcements in the polymer matrix are reported to improve the Interlaminar Shear Strength and Interlaminar Fracture Toughness of the composites. In the present investigation, epoxy glass fiber laminate composites were processed using hand layup and vacuum bagging technique. The particulate reinforcement precipitator fly ash (25 - 45 μm) was added in the epoxy matrix by mechanical mixing up to 10 wt%. The effects of fly ash reinforcement on the mechanical properties and Interlaminar Fracture Toughness were studied before and after exposure to aqueous fog in a salt fog chamber at 45°C. In unexposed condition Mode I interlaminar fracture toughness of epoxy glass fiber laminate composite improved by the addition of fly ash reinforcement 10% (By weight) by 49.43% and when it was subjected to aqueous fog for 10 days the interlaminar fracture toughness improved 58.42%. Exposure to aqueous fog for 10 days causes plasticization of resin matrix and weakening of fiber/matrix interface results in improvement in interlaminar fracture toughness. The fracture surfaces were analyzed using scanning electron microscopy.

关键词： Interlaminar Fracture Toughness Epoxy Glass Fiber Laminate Composite Fly Ash

Identification of arylamine N-acetyltransferase inhibitors as an approach towards novel anti-tuberculars

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Protein & Cell 2010年第1期1卷 82-95页

作者： Isaac M.Westwood Sanjib Bhakta Angela J.Russell Elizabeth Fullam Matthew C.Anderton Akane kawamura Andrew W.Mulvaney Richard J.Vickers Veemal Bhowruth Gurdyal S.Besra ajit Lalvani Stephen G.Davies Edith Sim Department of Pharmacology University of OxfordOxford OX13QTUnited Kingdom Chemistry Research Laboratory Department of Organic ChemistryUniversity of OxfordOxford OX13QLUnited Kingdom School of Biosciences University of BirminghamEdgbastonBirmingham B152TTUnited Kingdom Tuberculosis Immunology Group Department of Respiratory MedicineNational Heart and Lung InstituteWright Fleming Institute of Infection and ImmunityImperial College LondonNorfolk PlaceLondon W21PGUnited Kingdom Structure-Based Drug Design Team Sections of Structural Biology and Cancer TherapeuticsInstitute of Cancer ResearchChester Beatty LaboratoriesLondon SW36JBUnited Kingdom Institute of Structural and Molecular Biology Department of Biological ScienceBirkbeckUniversity of LondonLondon WC1E 7HXUnited Kingdom

New anti-tubercular drugs and drug targets are urgently needed to reduce the time for treatment and also to identify agents that will be effective against Mycobacterium tuberculosis persisting *** have a unique cell *** of the gene for arylamine N-acetyltransferase(NAT)decreases mycobacterial cell wall lipids,particularly the distinctive mycolates,and also increases antibiotic susceptibility and killing within macrophage of Mycobacterium bovis *** nat gene and its associated gene cluster are almost identical in sequence in *** BCG and *** gene cluster is essential for intracellular survival of *** have therefore used pure NAT protein for high-throughput screening to identify several classes of small molecules that inhibit NAT ***,we characterize one class of such molecules—triazoles—in relation to its effects on the target enzyme and on both *** BCG and *** most potent triazole mimics the effects of deletion of the nat gene on growth,lipid disruption and intracellular *** also present the structure-activity relationship between NAT inhibition and effects on mycobacterial growth,and use ligand-protein analysis to give further insight into the structure-activity *** conclude that screening a chemical library with NAT protein yields compounds that have high potential as anti-tubercular agents and that the inhibitors will allow further exploration of the biochemical pathway in which NAT is involved.

关键词： N-acetyltransferase Mycobacterium tuberculosis triazoles screening

Impact of ZnO Nano Materials on Medicinal Black Rice Seed Germination

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Journal of Minerals and Materials Characterization and Engineering 2019年第4期7卷 180-192页

作者： Shubhangi Mahajan Shilpa Barthwal Manpreet kaur Attri Sneh Bajpai Surbhi Dabral Manika khanuja ajit Varma Amity Institute of Microbial Technology Amity University Noida India Centre for Nanoscience and Nanotechnology Jamia Millia Islamia New Delhi India

Black rice Oryza sativa is primarily grown in East and North East of India. This variety could not become popular due to low yield and being expensive. It is rich in three kinds of Anthocyanin contents which exhibit great impact on human health. Four different kinds of ZnO nanomaterial were prepared at variable temperature ranging from 250°C to 500°C. The Interaction of black rice grain with nanozinc material leads to the observation that seeds germinated early. Rooting development was higher. Better effects were observed while those interacted with nanomaterial prepared at 350°C. In the present study the aim was to enhance the yield and value addition. To best of our knowledge this is the first scientific attempt [see also patent filed Varma et al. 2019]. The mechanism involved needs further elaborate elucidation. We hope that the goal can also be achieved by interaction of seeds with mycosymbiont—Piriformospora indica (Serendipita indica) a potent cultivable mycorrhiza. The precise objective of this communication is to illustrate the interaction of black rice seed with several synthesized nano zinc material which varied in shape, size and diameter.

关键词： Black Rice (Oryza sativa) Zinc Nanomaterials Piriformospora indica (Serendipita indica) Anthocyanin

Isolation, purification and characterization of an N-acetyl-D-lactosamine binding mitogenic and anti-proliferative lectin from tubers of a cobra lily Arisaema utile Schott

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Advances in Bioscience and Biotechnology 2010年第2期1卷 79-90页

作者： Vikram Dhuna kshitija Dhuna Jatinder Singh ajit kumar Saxena Satyam kumar Agrawal Sukhdev Singh kamboj 不详

Lectins are the carbohydrate-binding proteins of non-immune origin which have been the subject of intense investigation over the last few decades owing to the variety of interesting biological properties. Most of the lectins which have been purified and characterized from plants have been obtained from dicotyledons. In the present study a lectin was purified from tubers of a monocot plant Arisaema utile (AUL) Schott by affinity chromatography on asialofetuin-linked amino activated silica beads. AUL gave a single band in SDS-PAGE at pH 8.3 corresponding to subunit Mr 13.5 kDa. The native molecular mass of AUL was 54 kDa suggesting a homotetrameric structure. AUL gave multiple bands in isoelectric focusing and in native PAGE at pH 8.3. AUL was inhibited by N-acetyl-D-lactosamine (Lac NAc), a disaccharide and asialofetuin, a complex desialylated serum glycoprotein. When treated with denaturing agents, the lectin was stable in the presence of urea (3 M), thiourea (4 M) and guanidine HCl (4 M). AUL was a glycoprotein with a carbohydrate content of 1.2%. Complete loss of activity was observed upon modification of tryptophan residues of the lectin. The activity was reduced to 25% after modification of tyrosine. Chemical modification of arginine, histidine, serine and cysteine residues of AUL did not affect its activity. Using Far UV CD spectra the estimated secondary structure was 37% α-helix, 25% β-sheet and 38% random contributions. The lectin showed potent mitogenic response towards human lymphocytes. In vitro anti-proliferative assay using 11 human cancer cell lines resulted in 50% inhibition of six cell lines viz. SW-620, HCT-15, Sk-N-SH, IMR-32, Colo-205 and HT-29 at 38, 42, 43, 49, 50 and 89 µg/ml, respectively.

关键词： N-acetyl-D-lactosamine Arisaema Utile Affinity Purification Anti-Proliferative Asialofetuin Chemical Modification Lectin Mitogenicity

The Role of Hemagglutinin-esterase-fusion Glycoprotein from Newly-identified Influenza D Virus in Viral Entry

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The Role of Hemagglutinin-esterase-fusion Glycoprotein from ...

Should We Be Concerned? Comparison of Catheter and CT Angiogram for Arterial Distensibility at the Site of Carotid Stenosis during Catheter Angiography

第十一届全国免疫学学术大会

作者： Song Hao Qi Jianxun Varki ajit Shi Yi Gao George F Research Network of Immunity and Health (RNIH) Beijing Institutes of Life ScienceChinese Academy of Sciences CAS key Laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of Sciences University of California

Background:Of the Orthomyxoviridae family of viruses,influenza A,B and C viruses all can cause disease in ***,a novel influenza D virus(IDV) with approximately 50% amino acid identity to human influenza C virus(ICV) is found in pigs and *** novel virus has a broader cell tropism than human ICV and is capable of infecting ferrets,pigs and guinea pigs and transmit to naive animals by direct ***:To investigate the cellular receptor for viral entry and the molecular mechanism for its broad host ***:We determined the receptor of IDV by glycan microarray analysis,and determined the crystal structures of hemagglutinin-esterase-fusion glycoprotein(HEF) of IDV,both in its free form and in complex with the receptor and enzymatic substrate ***:We demonstrated that IDV(like ICV) uses 9-O-acetylated sialic acid as its receptor,but the IDV HEF has an open receptor-binding cavity to accommodate diverse extended glycan *** structural difference provides an explanation for the phenomenon that the IDV has a broad cell ***:Our findings reveal in exquisite detail how the receptors or substrates bind to the receptor-binding site or esterase active site,providing a clue for the development of novel therapeutics against the conserved esterase ***,the IDV HEF can bind human trachea epithelia,indicating that the IDV virus may become a potential threat to public health.

关键词： crystal structure HEF influenza D virus receptor binding viral entry

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Open Journal of Medical Imaging 2017年第4期7卷 237-247页

作者： Aly Abayazeed Juan Diego Lozano Gabriela Santos-Nunez Srinivasan Vendantham ajit Puri Ajay Wakhloo Deepak Takhtani Department of Radiology University of Massachusetts Medical School Worcester MA USA

Purpose: During catheter angiogram (CA) there is momentary increase in intravascular volume and pressure due to intra-arterial injection that can potentially cause vascular distention at the stenotic site, whereas on CT angiogram (CTA) is unlikely due to intravenous administration. Methods: CA and CTA of the carotid artery from 29 patients were retrospectively studied. CA and CTA were obtained for each patient. Curved sagittal MPRs mirroring the carotid artery on CA were used to measure the diameter at stenosis and at the distal lumen. Mural plaque calcium content was graded on axial CTAs. Results: Accounting for repeated measurements, the likelihood that the lumen diameter from CA will be larger than CTA was higher at stenosis than distal to it but the difference in lumen diameters at stenosis was similar to CTA. There is insufficient evidence that intra-arterial hand-injection during CA leads to underestimation of the degree of stenosis. Percentage stenosis using the NASCET criteria differed between the 3 measurements, post hoc analysis showed significant difference between CA and axial CTA (p p > 0.99). The difference in lumen diameter did not depend on our calcium grading (p = 0.484). Conclusions: There is insufficient evidence to suggest that intra-arterial hand-injection contributes to vessel distention and underestimation of percent stenosis during CA in this study. Mural plaque calcium does not affect the degree of stenosis on CTA.

关键词： Arterial Distensibility Carotid Stenosis Catheter Angiogram

Sonographic Evaluation of Pleural Effusion

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Open Journal of Medical Imaging 2017年第3期7卷 77-88页

作者： ajit kumar Reddy Sandeep Ballal kaup Annitha Elavarasi Jayamohan Prakash Manikka Lakshmanan krishnappa Nasappa Antony Jean Department of Radiodiagnosis KIMS Bangalore India Department of Radiodiagnosis HOSMAT Bangalore India Department of Radiodiagnosis MGMCRI Pondicherry India Department of Radiodiagnosis Aarthi Scans Tirunelveli India

Background: Although at times small amounts of pleural fluid is detected on the lateral decubitus chest radiograph, this may be impossible to obtain in severely ill patients. Because of its ready availability and ability for bedside imaging, ultrasonography has become a crucial imaging modality not only in detecting the presence of pleural fluid but also as a guide to aspiration. Aims: To sonographically determine the nature of pleural effusions. To analyze predictability of both benign and malignant pleural effusions and to study statistical value of various ultrasound characteristics in differentiating exudative and transudative as well as benign and malignant effusions in correlation with thoracocentesis. Material and Methods: Sonographic feature as well as fluid cytology was evaluated. Following categorization into exudates or transudate as well as benign or malignant the diagnosis was then correlated biochemically. Results: Transudates were anechoic, while an anechoic effusion may be either a transudate or an exudate. Complex septation, internal echoes, thickened pleura or homogeneously echogenic patterns were always exudates. Sonographic findings of pleural nodules and associated parenchymal lesions in the lung and liver were indicative of malignancy. Conclusions: Ultrasound in addition to being highly sensitive for pleural effusion also aided in characterizing the nature and minimizing the complications during thoracocentesis. Pleural effusions were categorized into exudates and transudate as well as benign and malignant with a certain degree of confidence based on sonographic findings.

关键词： Pleural Effusion Sonography Septation Internal Echoes Thoracocentesis

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高压浮置MOS栅驱动集成电路

电子器件 1992年第2期15卷 118-122页

作者： Steve Clemente ajit Dubhashi 张怡

引言如图1所示,将功率MOSFET或者IGBT用于全增强型的高压侧开关,其栅的驱动要求,即各端子的最低电压可归纳如下: 1、栅压应比漏电压高出10～15V。高压侧开关管的栅电位通常比系统中的最高电位──固定电平要高。 2、栅电位一般是对地... 详细信息

引言如图1所示,将功率MOSFET或者IGBT用于全增强型的高压侧开关,其栅的驱动要求,即各端子的最低电压可归纳如下: 1、栅压应比漏电压高出10～15V。高压侧开关管的栅电位通常比系统中的最高电位──固定电平要高。 2、栅电位一般是对地而言的,必须逻辑可控。因此,控制信号应抬高到高压侧功率器件的源电位,在大多数应用中,此源电位在两固定电平间摆动。 3、栅驱动电路所消耗的功率对整体效率不能有明显的影响。由于以上的限制,目前已采用好几种工艺可用来完成功能,原理见表Ⅰ,每一种基本电路均可用多种结构来实现。国际整流器公司的IR2110栅驱动器集成了驱动高压侧与低压侧功率MOSFET或IGBT所需的大部分功能,兼有小体积与高性能的封装。附加少许元件。IR2110便能提供很高的开关速度(见表Ⅱ)

关键词： MOS 集成电路

Effect of Intravenous Methylprednisolone on the Signs &Symptoms of Graves’ Ophthalmopathy

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Open Journal of Endocrine and Metabolic Diseases 2019年第9期9卷 95-101页

作者： Muhammad Shah Alam A. B. M. kamrul-Hasan Syeda Tanzina kalam ajit kumar Paul Shahjada Selim Department of Medicine Army Medical College Cumilla Bangladesh Department of Endocrinology Mymensingh Medical College Hospital Mymensingh Bangladesh Department of Medicine Cumilla Medical College Hospital Cumilla Bangladesh Department of Endocrinology Mainamati Medical College Cumilla Bangladesh Department of Endocrinology Bangabandhu Sheikh Mujib Medical University Dhaka Bangladesh

Background: Graves’ ophthalmopathy (GO) is the most frequent extrathyroidal manifestation of Graves’ disease (GD). The effect of intravenous methylprednisolone on the signs and symptoms of GO has not been evaluated in the Bangladeshi population. Objective: To observe the effect of intravenous methylprednisolone in active Graves’ ophthalmopathy. Materials/Methods: This prospective study conducted in a tertiary hospital of Bangladesh from May 2009 to November 2010 included 30 patients having moderate to severe ophthalmopathy. In addition to the clinical activity score (CAS), eye involvement was assessed by using the “NOSPECS” scoring system. Results: The mean (±SD) age of the patients was 38.1 ± 10.6 years and male-female ratio was 1.2:1. NOSPECS eye findings before treatment and during the final (3rd) visit of the patients were observed. It was found that lid retraction or lid lag was improved in 21 (70%) of the patients during the final visit. All of the patients had soft tissue swelling initially and all of them improved at the final visit. Bilateral proptosis was present in 19 patients before treatment and improved in 12 (62%) patients during the final visit. Right eye proptosis was present in 9 patients before treatment and improved in 5 (60%) patients during final visit. Extraocular muscle involvement (Diplopia) was present in 15 patients before treatment but improved in 13 (86.0%) patients during the final visit. A significant number of subjects showed significant improvement in all of the NOSPECS eye findings (except unilateral right eye proptosis) during the final visit;all had inactive GO (CAS Conclusion: Intravenous methylprednisolone appears to be an effective treatment option for active Graves’ ophthalmopathy.

关键词： Graves’ Ophthalmopathy NOSPECS Methylprednisolone