检索结果-南通市图书馆

Plant phosphatidylinositol-specific phospholipase C at the center of plant innate immunity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2017年第3期59卷 164-179页

作者： ahmed M.Abd-El-haliem Matthieu h.A.J.Joosten Laboratory of Phytopathology Wageningen University Droevendaalsesteeg 1 6708 PB Wageningen The Netherlands Plant Physiology Swammerdam Institute for Life Sciences University of Amsterdam Science Park 904 1098 XH Amsterdam The Netherlands

Understanding plant resistance to pathogenic microbes requires detailed information on the molecular mechanisms controlling the execution of plant innate immune responses. A growing body of evidence places phosphoinositide-specific phospholipase C （PI-PLC） en- zymes immediately downstream of activated immune receptors, well upstream of the initiation of early defense responses. An increase of the cytoplasmic levels of free Ca2＋, lowering of the intercellular ph and the oxidative burst are a few examples of such responses and these areregulated by PI-PLCs. Consequently, PI-PLC activation represents an early primary signaling switch between elicitation and response involving the controlled hydrolysis of essential signaling phospholipids, thereby simulta- neously generating lipid and non-lipid second messenger molecules required for a swift cellular defense response. here, we elaborate on the signals generated by PI-PLCs and their respective downstream effects, while providing an inventory of different types of evidence describing the involvement of PI-PLCs in various aspects of plant immunity. We project the discussed information into a model describing the cellular events occurring after the activation of plant immune receptors. With this review we aim to provide new insights supporting future research on plant PI-PLCs and the development of plants with improved resistance.

关键词： Pradeep Kachroo University of Kentucky USA

Role of human nucleoside transporters in pancreatic cancer and chemoresistance

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2021年第40期27卷 6844-6860页

作者： Carly Jade Carter ahmed h Mekkawy David L Morris hepatobiliary and Surgical Oncology Unit Department of SurgerySt George HospitalUniversity of New South WalesSydney 2217New South WalesAustralia Mucpharm Pty Ltd Australia

The prognosis of pancreatic cancer is poor with the overall 5-year survival rate of less than 5%changing minimally over the past decades and future projections predicting it developing into the second leading cause of cancer related mortality within the next *** into the mechanisms of pancreatic cancer development,progression and acquired chemoresistance have been constant for the past few decades,thus resulting in the identification of human nucleoside transporters and factors affecting cytotoxic uptake via said *** review summaries the aberrant expression and role of human nucleoside transports in pancreatic cancer,more specifically human equilibrative nucleoside transporter 1/2(hENT1,hENT2),and human concentrative nucleoside transporter 1/3(hCNT1,hCNT3),while briefly discussing the connection and importance between these nucleoside transporters and mucins that have also been identified as being aberrantly expressed in pancreatic *** review also discusses the incidence,current diagnostic techniques as well as the current therapeutic treatments for pancreatic ***,we address the importance of chemoresistance in nucleoside analogue drugs,in particular,gemcitabine and we discuss prospective therapeutic treatments and strategies for overcoming acquired chemoresistance in pancreatic cancer by the enhancement of human nucleoside transporters as well as the potential targeting of mucins using a combination of mucolytic compounds with cytotoxic agents.

关键词： Pancreatic cancer Gemcitabine human nucleoside transporters human equilibrative nucleoside transporters human concentrative nucleotide transporters Mucins

UV RADIATION INDUCED GRAFT COPOLYMERIZATION OF ALLYL ACETATE ONTO POLY(EThYLENE TEREPhThALATE)(PET) FILMS FOR FUEL CELL MEMBRANES

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2012年第2期30卷 227-234页

作者： Mostak ahmed Mubarak A.Khan Nazia Rahman M.Anwar h.Khan Radiation and Polymer Chemistry Laboratory Institute of Nuclear Science and TechnologyBangladesh Atomic Energy CommissionP.O.Box 3787DhakaBangladesh Department of Chemistry Shahjalal University of Science and TechnologySylhet-3114Bangladesh Department of Geography University of California BerkeleyBerkeleyCA 94720USA

Ultraviolet （UV）-induced graft copolymerization of allyl acetate （AA） monomer onto poly（ethylene terephthalate）（PET） films and the subsequent sulfonation on the monomer units in the grafting chain using chlorosulfonic acid （C1SO3h） were carried out to prepare proton exchange membranes （PEMs） for fuel cells. A maximum grafting value of 12.8% was found for 35 vol% allyl acetate after 3 h radiation time. Optimum concentration of C1SO3h was selected for the sulfonation reaction to be 0.05 mol/L based on the degree of sulfonation and the tensile strength studies of the membrane. The degree of sulfonation increased as the sulfonation reaction temperature and sulfonation time were increasing. The radiation grafting and the sulfonation have been confirmed by titrimetric and gravimetric analyses as well as FTIR spectroscopy. The maximum ion exchange capacity （IEC） of 0.04125 mmol g-1 was found at 12.1% degree of sulfonation and the maximum proton conductivity was found to be 0.035 S cm-1 at 30℃ and a relative humidity of 60%. The various physical and chemical properties of the PEMs such as water uptake, mechanical strength, thermal durability and oxidative stability were also studied. To investigate the suitability of the prepared membrane for fuel cell applications, its properties were compared with those ofNafion 117.

关键词： Polymer electrolyte membrane Allyl acetate Fuel cell UV radiation Grafting Sulfonation.

Model inference using the Akaike information criterion for turbulent flow of non-Newtonian crude oils in pipelines

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2015年第3期12卷 492-500页

作者： ahmed h.Kamel Ali S.Shaqlaih Essam A.Ibrahim College of Business & Engineering University of Texas of the Permian Basin Department of Mathematics & Information Sciences University of North Texas at Dallas

The friction factor is a crucial parameter in calculating frictional pressure losses. however, it is a decisive challenge to estimate, especially for turbulent flow of non-Newtonian fluids in pipes. The objective of this paper is to examine the validity of friction factor correla- tions adopting a new informative-based approach, the Akaike information criterion （AIC） along with the coeffi- cient of determination （R2）. Over a wide range of measured data, the results show that each model is accurate when it is examined against a specific dataset while the E1-Emam et al. （Oil Gas J 101：74-83, 2003） model proves its supe- riority. In addition to its simple and explicit form, it covers a wide range of flow behavior indices and generalized Reynolds numbers. It is also shown that the traditional belief that a high R2 means a better model may be mis- leading. AIC overcomes the shortcomings of R2 as a trade between the complexity of the model and its accuracy not only to find a best approximating model but also to develop statistical inference based on the data. The authors present AIC to initiate an innovative strategy to help alleviate several challenges faced by the professionals in the oil and gas industry. Finally, a detailed discussion and models＇ ranking according to AIC and R2 is presented showing the numerous advantages of *** Friction factor - Pipeline Information theory Non-Newtonian Turbulent

关键词： Friction factor - Pipeline Informationtheory Non-Newtonian Turbulent

New solitary waves and exact solutions for the fifth-order nonlinear wave equation using two integration techniques

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and Science 2023年第5期8卷 475-480页

作者： ahmed h.Arnous Mohammad Mirzazadeh Lanre Akinyemi Arzu Akbulut Department of Physics and Engineering Mathematics Higher Institute of EngineeringEl Shorouk AcademyCairoEgypt Department of Engineering Sciences Faculty of Technology and EngineeringEast of GuilanUniversity of GuilanRudsar-VajargahIran Department of Mathematics Lafayette CollegeEastonPennsylvaniaUSA Department of Mathematics Computer Faculty of Art ScienceEskisehir Osmangazi UniversityEskisehirTurkey

In this paper,we discussed the enhanced Kudryashov’s and general projective Riccati equations tech-niques for obtaining exact solutions to the fifth-order nonlinear water wave(FONLWWE)*** the enhanced Kudryashov’s method,we were able to achieve solitary wave and singular soliton ***-shock hybrid wave,singular soliton,and periodic wave solutions were discovered when we em-ployed the general projective Riccati equations *** can say the given methods are effective and powerful for obtaining exact *** findings in this paper are critical for explaining a wide range of scientific and oceanographic applications involving ocean gravity waves and other related phenomena.

关键词： Enhanced Kudryashov method Riccati equation Water waves Fifth-order nonlinear model Solitons

Investigation on the mechanical properties of sintered porous copper compacts

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Particuology 2007年第6期5卷 391-394页

作者： Yasser M.Z. ahmed Mohamed I. Riad ahmed I. Zaky Mohammed Abdel-Aziz Mohamed M.h. Shalabi Central Metallurgical Research and Development Institute CMRDI El-Felzat Street El-Tabbin P.O. Box 87 Helwan Cairo Egypt

In line with recent attention on porous metals having low and medium porosities in the range of 20-50%, this paper studies the effect of porosity on the mechanical properties of sintered copper compacts. Experiments were designed to investigate the effect of porosity, applied stress and sliding velocity on the wear rate of copper compacts, leading to the finding that the effects of both porosity and applied stress of the wear test on the wear rate are approximately similar and higher than that of sliding velocity. The investigation concerning the effect of porosity on compressive strength indicated that the stress-strain curve of high-porosity compact exhibited identifiable ultimate strength points, though low-porosity compact showed distinct stages of elastic plastic behavior.

关键词： Porous copper Wear rate Compressive strength Experimental design technique

Spirulina platensis extract improves the production and defenses of the common bean grown in a heavy metals-contaminated saline soil

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2023年第7期129卷 240-257页

作者： Mostafa M.Rady ahmed S.Elrys Eman Selem ahmed A.A.Mohsen Safaa M.A.I.Arnaout ahmed h.El-Sappah Khaled A.El-Tarabily El-Sayed M.Desoky Botany Department Faculty of AgricultureFayoum UniversityFayoum 63514Egypt College of Tropical Crops Hainan UniversityHaikou 570228China Soil Science Department Faculty of AgricultureZagazig UniversityZagazig 44511Egypt Botany and Microbiology Department Faculty of ScienceZagazig UniversityZagazig 44511Egypt horticulture Department Faculty of AgricultureZagazig UniversityZagazig 44511Egypt Botany Department Faculty of AgricultureZagazig UniversityZagazig 44511Egypt Genetics Department Faculty of AgricultureZagazig UniversityZagazig 44511Egypt Department of Biology College of ScienceUnited Arab Emirates UniversityAl-Ain 15551United Arab Emirates Khalifa Center for Genetic Engineering and Biotechnology United Arab Emirates UniversityAl-Ain 15551United Arab Emirates harry Butler Institute Murdoch UniversityMurdoch 6150Australia

Plants have to cope with several abiotic stresses,including salinity and heavymetals(hMs).Under these stresses,several extracts have been used as effective natural biostimulants,however,the use of Spirulina platensis(SP)extract(SPE)remains *** effects of SPE were evaluated as soil addition(SA)and/or foliar spraying(FS)on antioxidant defenses and hMs content of common bean grown in saline soil contaminated with ***(40 or 80 mg SPE/hill added as SA or 20 or 40 mg SPE/plant added as FS)or integrative(SA+FS)applications of SPE showed significant improvements in the following order:SA-80+FS-40>SA-80+FS-20>SA-40+FS-40>SA-40+FS-20>SA-80>SA-40>FS-40>FS-20>***,the integrative SA+FS with 40 mg SP/plant was the most effective treatment in increasing plant growth and production,overcoming stress effects and minimizing contamination of the edible *** significantly increased plant growth(74%–185%)and yield(107%–227%)by enhancing net photosynthetic rate(78.5%),stomatal conductance(104%),transpiration rate(124%),and contents of carotenoids(60.0%),chlorophylls(49%–51%),and NPK(271%–366%).These results were concurrent with the marked reductions in malondialdehyde(61.6%),hydrogen peroxide(42.2%),nickel(91%–94%),lead(80%–9%),and cadmium(74%–91%)contents due to the improved contents of glutathione(87.1%),ascorbate(37.0%),andα-tocopherol(77.2%),and the activities of catalase(18.1%),ascorbate peroxidase(18.3%),superoxide dismutase(192%),and glutathione reductase(52.2%)as reinforcing ***,this most effective treatment is recommended to mitigate the stress effects of salinity and hMs on common bean production while minimizing hMs in the edible part.

关键词： Antioxidant defense system Biostimulants heavy metals Microalgae extracts Saline soil Soil pollution

Self-Dual Weak hopf Algebras

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2008年第12期24卷 1935-1948页

作者： Munir ahmed Department of Mathematics Zhejiang University Hangzhou Zhejiang 310027 P. R. China

In this paper, we define the notion of self-dual graded weak hopf algebra and self-dual semilattice graded weak hopf algebra. We give characterization of finite-dimensional such algebras when they are in structually simple forms in the sense of E. L. Green and E. N. Morcos. We also give the definition of self-dual weak hopf quiver and apply these types of quivers to classify the finite- dimensional self-dual semilattice graded weak hopf algebras. Finally, we prove partially the conjecture given by N. Andruskiewitsch and h.-J. Schneider in the case of finite-dimensional pointed semilattice graded weak hopf algebra h when grh is self-dual.

关键词： weak hopf algebra self-duality weak hopf quiver

Updates in the pathophysiological mechanisms of Parkinson's disease: Emerging role of bone marrow mesenchymal stem cells

在线全文

学校读者我要写书评

暂无评论

World Journal of Stem Cells 2016年第3期8卷 106-117页

作者： hanaa h ahmed ahmed M Salem hazem M Atta Emad F Eskandar Abdel Razik h Farrag Mohamed A Ghazy Neveen A Salem hadeer A Aglan Department Medical Research Division National Research Centre Biochemistry Department Faculty of Science Ain Shams University Clinical Biochemistry Department Faculty of Medicine King Abdulaziz University Medical Biochemistry and Molecular Biology Department Faculty of Medicine Cairo University Pathology Department Medical Research Division National Research Centre Narcotics Ergogenic aids and Poisons Department Medical Research Division National Research Centre

AIM: To explore the approaches exerted by mesenchymal stem cells (MSCs) to improve Parkinson’s disease (PD) ***: MSCs were harvested from bone marrow of femoral bones of male rats, grown and propagated in culture. Twenty four ovariectomized animals were classified into 3 groups: Group (1) was control, Groups (2) and (3) were subcutaneously administered with rotenone for 14 d after one month of ovariectomy for induction of PD. Then, Group (2) was left untreated, while Group (3) was treated with single intravenous dose of bone marrow derived MSCs (BM-MSCs). SRY gene was assessed by PCR in brain tissue of the female rats. Serum transforming growth factor beta-1 (TGF-β1), monocyte chemoattractant protein-1 (MCP-1) and brain derived neurotrophic factor (BDNF) levels were assayed by ELISA. Brain dopamine DA level was assayed fluorometrically, while brain tyrosine hydroxylase (Th) and nestin gene expression were detected by semi-quantitative real time PCR. Brain survivin expression was determined by immunohistochemical procedure. histopathological investigation of brain tissues was also ***: BM-MSCs were able to home at the injured brains and elicited significant decrease in serum TGF-β1 (489.7 ± 13.0 vs 691.2 ± 8.0, P h significant increase in serum BDNF (3663 ± 17.8 vs 2905 ± 72.9, P h (1.18 ± 0.004 vs 0.54 ± 0.009, P he number of positive cells for survivin (293.2 ± 15.9 vs 271.5 ± 15.9, P > 0.05) expression. Finally, the brain sections showed intact histologica

关键词： Parkinson’s disease Pathophysiology Bone marrow derived mesenchymal stem cells Rotenone Anti-inflammatory action Ovariectomy Anti-apoptotic effect Neurogenic potential