检索结果-南通市图书馆

Mangrove derived fungal endophytes–a chemical and biological perception

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fungal Diversity 2013年第4期61卷 1-27页

作者： Abdessamad Debbab Amal H.aly Peter Proksch Heinrich-Heine-Universität Düsseldorf Institut für Pharmazeutische Biologie und BiotechnologieUniversitätsstr.1Geb.26.2340225 DüsseldorfGermany

The potential of mangrove-derived endophytic fungi as a promising source of diverse and structurally unprecedented bioactive natural products is unquestionable and continues to attract considerable *** review highlights new bioactive mangrove fungal metabolites and known compounds with hitherto unreported biological activities described during the last 10 *** compounds are categorized according to their reported biological activities,including cytotoxic,anti-infective,in addition to a wide range of miscellaneous activities such as protein kinase,αglucosidase,acetylcholinesterase and tyrosinase inhibitory activities,as well as antiangiogenic and neovascularisation effects,radical scavenging,DNA-binding affinity,and calcium and potassium channel blocking activity.

关键词： Fungi Endophytes Mangroves Bioactive natural products

PLANNED LEAD TiME OPTiMiZATiON iN MATERiAL REQUiREMENT PLANNiNG ENViRONMENT FOR MULTiLEVEL PRODUCTiON SYSTEMS

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 Systems Science and Systems Engineering 2008年第2期17卷 132-155页

作者： Faicel HNAiEN Alexandre DOLGUi Mohamed-aly OULD LOULY industrial Engineering and Computer Science Centre(G2i)Ecole des Mines de St Etienne 158cours Fauriel42023 Saint EtienneFrance King Saud University College of Engineering-industrial Engineering Department P.O.B 800 Riyadh 11421Kingdom of Saudi Arabia

This paper deals with the problem of planned lead time calculation in a Material Requirement Planning （MRP） environment under stochastic lead times. The objective is to minimize the sum of holding and backlogging costs. The proposed approach is based on discrete time inventory control where the decision variables are integer. Two types of systems are considered： multi-level serial-production and assembly systems. For the serial production systems （one type of component at each level）, a mathematical model is suggested. Then, it is proven that this model is equivalent to the well known discrete Newsboy Model. This directly provides the optimal values for the planned lead times. For multilevel assembly systems, a dedicated model is proposed and some properties of the decision variables and objective function are proven. These properties are used to calculate lower and upper limits on the decision variables and lower and upper bounds on the objective function. The obtained limits and bounds open the possibility to develop an efficient optimization algorithm using, for example, a Branch and Bound approach. The paper presents the proposed models in detail with corresponding proofs and se＇~eral numerical examples. Some advantages of the suggested models and perspectives of this research are discussed.

关键词： Multilevel assembly and production control model planned lead time optimization systems MRP random lead times discrete inventory

Turing instability in a diffusive SiS epidemiological model

在线全文

学校读者我要写书评

暂无评论

international Journal of Biomathematics 2015年第1期8卷 69-79页

作者： Shaban aly Houari B. Khenous Fatma Hussien Department of Mathematics Faculty of Science King Khalid University Abha 9005 Kingdom of Saudi Arabia Department of Mathematics Faculty of Science Assiut University Egypt

Modeling and simulation of infectious diseases help to predict the likely outcome of an epidemic. in this paper, a spatial susceptible-infective-susceptible （SiS） type of epidemiological disease model with self- and cross-diffusion are investigated. We study the effect of diffusion on the stability of the endemic equilibrium with disease-induced mortality and nonlinear incidence rate, in the absence of diffusion the stationary solution stays stable but becomes unstable with respect to diffusion and that Turing instability takes place. We show that a standard （self-diffusion） system may be either stable or unstable, cross-diffusion response can stabilize an unstable standard system or decrease a ＂ihlring space （the space which the emergence of spatial patterns is holding） compared to the ~lhlring space with self-diffusion, i.e. the cross-diffusion response is an important factor that should not be ignored when pattern emerges. Numerical simulations are provided to illustrate and extend the theoretical results.

关键词： SiS epidemiological model reaction-diffusion equation diffusive instability Turing instability.

Transpressive Structures in the Ghadir Shear Belt, Eastern Desert, Egypt: Evidence for Partitioning of Oblique Convergence in the Arabian-Nubian Shield during Gondwana Agglutination

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2019年第6期93卷 1614-1646页

作者： Mohamed ABD EL-WAHED Samir KAMH Mahmoud ASHMAWY aly SHEBL Geology Department Faculty of Science Tanta University

Transpressional deformation has played an important role in the late Neoproterozoic evolution of the ArabianNubian Shield including the Central Eastern Desert of *** Ghadir Shear Belt is a 35 km-long,NW-oriented brittleductile shear zone that underwent overall sinistral transpression during the Late *** this shear belt,strain is highly partitioned into shortening,oblique,extensional and strike-slip structures at multiple ***,strain partitioning is heterogeneous along-strike giving rise to three distinct structural *** the East Ghadir and Ambaut shear belts,the strain is pure-shear dominated whereas the narrow sectors parallel to the shear walls in the West Ghadir Shear Zone are simple-shear *** domains are comparable to splay-dominated and thrust-dominated strike-slip shear *** kinematic transition along the Ghadir shear belt is consistent with separate strike-slip and thrustsense shear *** earlier fabric(S1),is locally recognized in low strain areas and SW-ward thrusts.S2 is associated with a shallowly plunging stretching lineation(L2),and defines^NW-SE major upright macroscopic folds in the East Ghadir shear belt.F2 folds are superimposed by^NNW–SSE tight-minor and major F3 folds that are kinematically compatible with sinistral transpressional deformation along the West Ghadir Shear Zone and may represent strain partitioning during deformation.F2 and F3 folds are superimposed by ENE–WSW gentle F4 folds in the Ambaut shear *** sub-parallelism of F3 and F4 fold axes with the shear zones may have resulted from strain partitioning associated with simple shear deformation along narrow mylonite zones and pure shear-dominant deformation in fold *** ENEstriking shear zones were subsequently active at ca.595 Ma,coeval with sinistral shearing along NW-to NNW-striking shear *** occurrence of upright folds and folds with vertical axes suggests that transpression plays a significant role in

关键词： Arabian-Nubian Shield Ghadir shear belt transpression splay-dominated and thrust-dominated strike-slip shear zones Egypt

Endophytes and associated marine derived fungi—ecological and chemical perspectives

在线全文

学校读者我要写书评

暂无评论

Fungal Diversity 2012年第6期57卷 45-83页

The potential of endophytes and algal or invertebrate associated marine derived fungi as promising sources of structurally unprecedented bioactive natural products is undeniable and continues to attract broad *** review highlights new bioactive fungal metabolites reported in 2011 until April 2012,as well as known compounds for which novel biological activities have been *** compounds are grouped according to their reported biological activities which include cytotoxic,anti-infective,as well as radical scavenging,enzyme inhibition,anti-fouling and anti-parasitic ***,178 fungal metabolites,including 138 new natural products are ***,new insights into fungal-host interaction,chemical communication,and chemo-ecological roles of fungal metabolites,as well as new strategies for bioprospecting are presented.

关键词： Fungi Endophytes Associated marine fungi Bioactive metabolites Natural products Biosynthetic pathways

New Polymer Syntheses Part 60: A Facile Synthetic Route to Polyamides Based on Thieno[2,3-b]thiophene and Their Corrosion inhibition Behavior

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 2018年第7期36卷 835-847页

作者： Kamal i.aly Amr H.Moustafa Essam K.Ahmed Hany M.Abd El-lateef Mohamed Gamal Mohamed Sahar M.Mohamed Polymer Research Lab Chemistry Department Faculty of Science Assiut University Chemistry Department Faculty of Science Sohag University Chemistry Department Faculty of Science Minia University Chemistry Department College of Science King Faisal university

Polyamides containing thieno[2,3-b]thiophene moiety were prepared via a simple polycondensation reaction of the diaminothieno[2,3-b]thiophene monomer la with different kinds of diacid chlorides （including oxalyl, adipoyl, sebacoyl, isophthaloyl, terephthaloyl, 4,4＇-azodibenzoyl, 3,3＇-azodibenzoyl, p-phenylene diacryloyl） in the presence of LiC1 and NMP as a solvent through lowtemperature solution polycondensation. The chemical structures of model compound and synthesized polyamides were confirmed by FTiR, nuclear magnetic resonance spectroscopy （including 1 H-NMR and 13 C-NMR） and elemental analysis. in addition, the thermal stability, crystallinity structure and surface morphology of synthesized polyamides were characterized via thermogravametric analysis （TGA）, wide-angle X-ray diffraction analysis （WAXD） and scanning electron microscopy （SEM）. Also, the corrosion inhibition behavior of selected examples ofpolyamides was investigated; the inhibitive effect of the investigated polymers for carbon steel in 1.0 mol＇L-1 HCi was studied using potentiodynamic polarization （PDP） and electrochemical impedance spectroscopy （EiS） methods. PDP results displayed that the polyamides containing thieno[2,3-b]thiophene moiety can be as mixed-type inhibitors. The inhibition efficiency （P, %） was found to be in the range from 67.13% to 96.01%. There is an increase in P by the synthesized polymers in comparison to the starting monomer. The adsorption of these polymers was found to obey Langmuir adsorption isotherm.

关键词： Thieno[2 3-b]thiophene Polymer synthesis Thermal properties industrial applications Corrosion inhibition

Cardiac catheterisation in nonagenarians： Single center experience

在线全文

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2012年第2期9卷 148-152页

作者： Marc-Alexander Ohlow aly Hassan Ulrich Lotze Bemward Lauer Department of Cardiology Zentralklinik Bad Berka Robert Koch-Allee 9 99437 Bad Berka Germany Department of Cardiology Faculty of Medicine Alexandria University El-Guish Road El-Shatby Alexandria 21526 Egypt Department of internal Medicine DRK Krankenhaus Sonderhausen Hospitalstrasse 2 99706 Sondershausen Germany

Objective To explore the treatment, procedure related risks, and outcomes of patients older than 90 years of age undergoing cardiac catheterization. Methods We retrospectively studied 32 patients ≥ 90 years （93.0 ± 1.2 years） who underwent cardiac catheterisation in a tertiary specialist hospital （0.2% of 14,892 procedures during three years）. The results were compared to a patient cohort younger than 90 years of age. Results Baseline characteristics revealed a higher prevalence of diabetes （P 〈 0.001）, chronic obstructive pulmonary disease （P 〈 0.04）, previous myocardial infarction （P 〈 0.02）, and complex coronary anatomy （SYNTAX score 33 vs. 19） in nonagenarians. Patients 〈 90 years of age showed more hyperlipidemia （P 〈 0.01） and previous percutaneous coronary interventions （P 〈 0.015）. Nonagenarians underwent coronary angiography more often for acute coronary syndrome （ACS）（P 〈 0.003）, were presented more often in cardiogenic shock （P 〈 0.003）, and were transferred faster to coronary angiography in cases ofACS （P 〈 0.0001）. The observed in-hospital mortality rate （13% study group vs. 1% control group; P 〈 0.003） in nonagenarians was lower than the calculated rate of thrombolysis in myocardial infarction （TiMi） and global registry of acute cardiac events （GRACE） mortality and strongly influenced by the severity of clinical presentation and the presence of co-morbidities. Conclusion Despite the common scepticism that cardiac catheterisation exposes patients 〉 90 years to an unwarranted risk, our data demonstrate an acceptable incidence of complications and mortality in this group of patients.

关键词： Nonagenarian Acute coronary syndrome Complications Coronary angiography

Conservation laws,Lie symmetries,self adjointness,and soliton solutions for the Selkov–Schnakenberg system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第2期76卷 29-44页

作者： Kashif Ali aly R Seadawy Syed T R Rizvi Noor Aziz Department of Mathematics COMSATS University IslamabadLahore CampusPakistan Mathematics Department Faculty of ScienceTaibah UniversityAl-Madinah Al-Munawarah41411Saudi Arabia

in this article,we explore the famous Selkov–Schnakenberg(SS)system of coupled nonlinear partial differential equations(PDEs)for Lie symmetry analysis,self-adjointness,and conservation ***,miscellaneous soliton solutions like dark,bright,periodic,rational,Jacobian elliptic function,Weierstrass elliptic function,and hyperbolic solutions of the SS system will be achieved by a well-known technique called sub-ordinary differential *** these results are displayed graphically by 3D,2D,and contour plots.

关键词： Selkov-Schnakenberg system Lie symmetry analysis conservation laws adjointness integrability

Propagation of traveling wave solutions to the Vakhnenko-Parkes dynamical equation via modified mathematical methods

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2022年第1期37卷 21-34页

作者： aly R.Seadawy Asghar Ali Wafaa A.Albarakati Dumitru Baleanu Mathematics department Faculty of scienceTaibah UniversityAl-Madinah Al-MunawarahSaudi Arabia Mathematics Department University of EducationLahoreMultan CampusPakistan Mathematics Department Faculty of scienceKing Abdulaziz UniversityJeddahSaudi Arabia Department of Mathematics Cankaya UniversityAnkaraTurkey

in this paper, we investigate some new traveling wave solutions to Vakhnenko-Parkes equation via three modified mathematical methods. The derived solutions have been obtained including periodic and solitons solutions in the form of trigonometric, hyperbolic, and rational function solutions. The graphical representations of some solutions by assigning particular values to the parameters under prescribed conditions in each solutions and comparing of solutions with those gained by other authors indicate that these employed techniques are more effective, efficient and applicable mathematical tools for solving nonlinear problems in applied science.

关键词： Vakhnenko-Parkes equation(VPE) generalized direct algebraic method extended simple equation method modified F-expansion method