检索结果-南通市图书馆

Journal of Pharmaceutical Analysis 2017年第1期7卷 71-75页

作者： Susithra Selvam ivy Sarkar Department of Chemistry Vel Tech University Avadi Chennai 600062 Tamilnadu India Department of Chemistry Indian Institute of Technology Madras Chennai 600036 Tamilnadu India

Methylene blue(MB) is a hydrophobic drug molecule, having importance both as a staining reagent and pharmaceutical agent. MB is strongly fluorescent, with an emission peak at 686 nm(λ_(ex)665 nm). In the study,the possibility of MB as an extrinsic fluorophore to study the micellization behavior of bile salts(BSs) was carried out. Since BSs are drug delivery systems, the solubilization of hydrophobic MB drug molecule by BSs was achieved and the nature of association of MB with BS media, namely sodium cholate(Na C) and sodium deoxycholate(Na DC) was evaluated. Change in the photophysical properties of MB is monitored through fluorescence intensity and fluorescence anisotropy at emission peak, 686 nm of MB. Molecular mechanics calculations were carried out to evaluate the MB–BS association. The estimated heat of formation, ΔH_f values are –625.19 kcal/mol for MB–Na C and –757.48 kcal/mol for MB–Na DC. The photophysical study also revealed that MB reports the step-wise aggregation pattern of BSs media, as an extrinsic fluorescence probe.

关键词： Methylene blue Sodium deoxycholate Sodium cholate Absorption Fluorescence spectroscopy Molecular mechanics

Denaturation studies on bovine serum albumin–bile salt system:Bile salt stabilizes bovine serum albumin through hydrophobicity

在线全文

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2018年第1期8卷 27-36页

作者： Karpagaraj Malarkani ivy Sarkar Susithra Selvama Department of Chemistry Vel Tech UniversityAvadiChennai 600062India Department of Chemistry Indian Institute of Technology MadrasChennai 600036India Department of Chemistry PSG College of TechnologyPeelameduCoimbatore 641004India

Protein denaturation is under intensive research, since it leads to neurological disorders of severe consequences. Avoiding denaturation and stabilizing the proteins in their native state is of great importance,especially when proteins are used as drug molecules or vaccines. It is preferred to add pharmaceutical excipients in protein formulations to avoid denaturation and thereby stabilize them. The present study aimed at using bile salts(BSs), a group of well-known drug delivery systems, for stabilization of *** serum albumin(BSA) was taken as the model protein, whose association with two BSs, namely sodium cholate(Na C) and sodium deoxycholate(Na DC), was studied. Denaturation studies on the preformed BSA-BS systems were carried out under chemical and physical denaturation conditions. Urea was used as the chemical denaturant and BSA-BS systems were subjected to various temperature conditions to understand the thermal(physical) denaturation. With the denaturation conditions prescribed here,the data obtained is informative on the association of BSA-BS systems to be hydrophobic and this effect of hydrophobicity plays an important role in stabilizing the serum albumin in its native state under both chemical and thermal denaturation.

关键词： Bile salts Bovine serum albumin Chemical denaturation Thermal denaturation Tryptophan fluorescence Protein stabilization

Hendra Virus Re-visited

在线全文

学校读者我要写书评

暂无评论

Virologica Sinica 2009年第2期24卷 105-109页

作者： hume Field Dept Primary Industries and Fisheries QueenslandAustralia & Australian Biosecurity Cooperative Research Centre for Emerging Infectious Diseases

Hendra virus,a novel member of the family Paramyxovirus that has emerged from bats in Australia,causes fatal disease in livestock and humans. Eleven spillover events have been identified since the first description of the virus in 1994,resulting in a total of 37 equine cases and six human cases. All human cases have been attributed to exposure to infected horses;there is no evidence of bat-to-human or human-to-human transmission. Low infectivity and a high case fatality rate are features of Hendra virus infection in both horses and humans. The temporal pattern of spillover events suggests seasonal factors(plausibly be environmental,biological or ecological) as the proximate triggers for spillover. Minimisation of the future occurrence and impact of Hendra virus infections requires an understanding of the ecology of flying foxes,of virus infection dynamics in flying foxes,and of the factors that promote spillover. Management strategies seek to minimize the opportunity for effective contact between bats and horses,and limit potential horse-to-horse and horse-to-human transmission. Incomplete knowledge of the ecology of the virus,of the proximate factors associated with spillover,and the inherent difficulties of effectively managing wild populations,preclude a management approach targeted at bats.

关键词： Hendra virus Bats Zoonoses Emergence Epidemiology

A critical review of carbonate reservoir wettability modification during low salinity waterflooding

在线全文

学校读者我要写书评

暂无评论

Petroleum 2023年第3期9卷 317-330页

作者： Perekaboere ivy Sagbana Kwame Sarkodie Wilberforce Aggrey Nkrumah Zone 63 District 841DohaQatar Petroleum Engineering Department Kwame Nkrumah University of Science and TechnologyGhana Smart Fluids Laboratory Kwame Nkrumah University of Science and TechnologyGhana

The nature of carbonate reservoirs promotes the adsorption of oil onto the rock surface hence making oil recovery a challenge even with the interventions of varied chemical EOR ***,low salinity water flooding has become of great interest since it is cost-effective and environmentally *** low salinity waterflooding has been highly investigated in sandstone reservoirs,it is not the same for carbonate reservoirs due to its ***,it has been proposed as a favourable technique to mobilise the trapped oil in carbonate *** alteration is regarded as the most accepted mechanism for low salinity flooding but has not been well understood making field scale applications *** this paper,we present a detailed review of the wettability alteration mechanisms in carbonate reservoirs during low salinity *** influencing wettability alteration in carbonates and the interactions that occur at the rock/brine/oil interface are also *** different methods utilised for wettability measurements during low salinity waterflooding are also reviewed including their drawbacks and advantages and *** will provide an improved understanding of the low salinity flooding application in carbonate reservoirs.

关键词： Low salinity flooding Wettability alteration Carbonate rocks

Locomotor recovery after spinal cord injury:intimate dependence between axonal regeneration and re-connection

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2022年第3期17卷 553-554页

作者： hector Ramiro Quintá Consejo Nacional de Investigaciones Científicas y Técnicas CONICET Laboratorio de Medicina Experimental“Dr.Jorge E.Toblli” Hospital AlemánBuenos AiresArgentina

Traumatic spinal cord injuries(SCI) are characterized by damage in the integrity of the spinal cord,which results in either temporary or permanent alterations in the locomotor,sensory and/or autonomic functions(Yezierski,2009).The traumatic event leads to impairments in voluntary control of movement below the injury by affecting the connection between the brain and the neurons localized in the spinal cord.

关键词： injuries alterations damage

Beam design for voice coil motors used for energy harvesting purpose with low frequency vibrations:A finite element analysis

在线全文

学校读者我要写书评

暂无评论

International Journal of Modeling, Simulation, and Scientific Computing 2016年第3期7卷 1-17页

作者： hector A.Tinoco Department of Mechanics and Production Universidad Autonoma de Manizales(UAM)Grupo de Diseno Mecanico y Desarrollo Industrial Antigua Estaci´on del Ferrocarril Edificio Sacatin C.P.170001 Manizales-Caldas Colombia

In this study,a numerical approach is established to design a beam coupled to a Voice Coil Motor(VCM)with the aim to maximize the displacement in the inductive transducer.A finite element model is developed to simulate a VCM with different beams applying a harmonic *** VCM is extracted from a recycled hard disk drive(HDD)and a parametric modal analysis is performed to identify the material parameters of the HDD and the *** parameters are obtained comparing the real vibration modes and natural frequencies(VCM-beam)with those determined from the finite element model.A numerical-experimental case study is carried out to demonstrate that if a beam is designed for a specific low frequency vibration between 0 and 10 Hz,the displacements are maximized in the *** this purpose,real acceleration measurements taken from three individuals are used to provide the vibration signals in the numerical model.A beam is designed for one of the individuals using the natural frequency values determined from the measured *** show that the displacements are maximized in the model which coincides with the natural frequency of the chosen *** main purpose of this research is to establish a design tool for energy harvesting purposes with VCM based on low frequency vibration sources as for example gait motions.

关键词： Hard disk drive HDD energy harvesting finite element analysis Wiimote voice coil motor VCM modal analysis

Hydrogen-based direct reduction of industrial iron ore pellets:Statistically designed experiments and computational simulation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2022年第10期29卷 1908-1921页

作者： Patrícia Metolina Tiago Ramos Ribeiro Roberto Guardani Chemical Systems Engineering Center Department of Chemical EngineeringUniversity of São PauloSão Paulo 05508-900Brazil Metallurgical Process Laboratory Institute of Technological ResearchSão Paulo 05508-901Brazil

As part of efforts to reduce anthropogenic CO_(2) emissions by the steelmaking industry,this study investigated the direct reduction of industrially produced hematite pellets with H_(2) using the Doehlert experimental design to evaluate the effect of pellet diameter(10.5-16.5 mm),porosity(0.36-0.44),and temperature(600-1200℃).A strong interactive effect between temperature and pellet size was observed,indicating that these variables cannot be considered *** increase in temperature and decrease in pellet size considerably favor the reduction rate,while porosity did not show a relevant *** change in pellet size during the reduction was negligible,except at elevated temperatures due to crack formation.A considerable decrease in mechanical strength at high temperatures suggests a maximum process operating temperature of 900℃.Good predictive capacity was achieved using the modified grain model to simulate the three consecutive non-catalytic gas-solid reactions,considering different pellet sizes and porosities,changes during the reaction from 800 to 900℃.However,for other temperatures,different mechanisms of structural modifications must be considered in the *** results represent significant contributions to the development of ore pellets for CO_(2)-free steelmaking technology.

关键词： hydrogen use non-catalytic gas-solid reaction grain model porous hematite pellet CO_(2)emissions reduction Doehlert experimental design

Inference for a truncated positive normal distribution

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2018年第2期33卷 163-176页

作者： hector J.Gomez Neveka M.Olmos hector Varela Heleno Bolfarine Departamento de Ciencias Matematicas y Ffsicas Facultad de IngenierlaUniversidad Catolica de TemucoTemucoChile Departamento de Matematicas Facultad de Ciencias BasicasUniversidad de AntofagastaAntofagastaChile Departamento de Estatfstica IMEUniversidade de Sao PauloSao PauloBrazil

The main object of this paper is to study an extension of the half normal distribution defined by adding a positive truncation to it. The new model is more flexible than the half-normal distribution and contains the half normal distribution as a special case. Properties of this distribution, such as moments, hazard function and entropy are studied and parameters estimation is dealt with by using inoinents and inaxiinuin likelihood. A real data application indicates good fit performance of the new model when compared to other competitors in litera- tures.

关键词： half-normal distribution maximum likelihood truncation

Molecular aspects of mammalian fertilization

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2001年第4期3卷 243-249页

作者： hector Serrano Dolores garcia-Suarez Dept. Health Sciences Dept. Biology Universidad Autonoma Metropoliana-Iztapalapa Ave. Michoacan and Purisima Mexico City DF 09340 Mexico

Mammalian fertilization is a highly regulated process, much of which are not clearly understood. Here we presentsome information in order to elaborate a working hypothesis for this process, beginning with the sperm modifications inthe epidydimis up to sperm and egg plasmalemma interaction and fusion. We also discuss the still poorly understood ca-pacitation process, the phenomenon of sperm chemo-attraction that brings the capacitated sperm to interact with theoocyte vestments and certain aspects of the acrosome reaction. (Asian J Androl 2001 Dec; 3 : 243 - 249)

关键词： fertilization sperm maturation sperm capacitation sperm-ovum interactions membrane fusion

The implementation and data analysis of an interferometer for intense short pulse laser experiments

在线全文

学校读者我要写书评

暂无评论

High Power Laser Science and Engineering 2016年第3期4卷 60-66页

作者： Jaebum Park hector A.Baldis Hui Chen Lawrence Livermore National Laboratory University of California

We present an interferometry setup and the detailed fringe analysis method for intense short pulse(SP) laser *** interferometry scheme was refined through multiple campaigns to investigate the effects of pre-plasmas on energetic electrons at the Jupiter Laser Facility at Lawrence Livermore National Laboratory. The interferometer used a frequency doubled(λ=0.527 μm) 0.5 ps long optical probe beam to measure the pre-plasma density, an invaluable parameter to better understand how varying pre-plasma conditions affect the characteristics of the energetic electrons. The hardware of the diagnostic, data analysis and example data are presented. The diagnostic setup and the analysis procedure can be employed for any other SP laser experiments and interferograms, respectively.

关键词： Mach-Zehnder interferometer optical interferometry picosecond probe plasma density short pulse laser