检索结果-南通市图书馆

Example Use of Low-Cost System for Capturing the Kinetic Parameters of Sperm Cells in Atlantic Salmon (<i>Salmo salar</i>)

在线全文

学校读者我要写书评

暂无评论

Advances in Bioscience and Biotechnology 2015年第2期6卷 63-72页

作者： Jorge Parodi Alfredo Ramírez-Reveco Guillermo guerra Laboratorio de fisiología de la Reproducción Núcleo de Producción Alimentaria Escuela de Medicina Veterinaria Facultad de Recursos Naturales Universidad Católica de Temuco Temuco Chile Laboratorio de Criobiología y Análisis de funcionalidad Espermática Instituto de Ciencia Animal Facultad de Ciencias Veterinarias Universidad Austral de Chile Valdivia Chile

A spermiogramme is an analysis performed to assess the quality of semen. Motility parameters are primarily obtained by subjectively observing samples or by using complex systems, such as computer-assisted sperm analysis (CASA). Here, we describe an easy and low-cost analysis system for obtaining quantifiable kinetic observations using Salmo salar semen model. In this work, we observed and captured video images of both fresh and stored Atlantic salmon semen to describe the possibility of analysis using the ImageJ CASA plug-in application for the kinetic parameters obtained from the videos. The semen is exposed to “powermilt”, a commercial activating solution, and the curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP) values are described. When the samples were activated after having been stored, differences were detected in sperm quality, using the low-cost plug-in application. However, this system was not able to detect small variations in the same recorded sample, suggesting limits in sample observation. The results indicate that it is possible to quantify the kinetic parameters of semen samples using a low-cost video system and free software.

关键词： fish Semen Motility Low Cost

Numerical simulation of wave transformation,breaking and runup by a contravariant fully non-linear Boussinesq equations model

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

Journal of Hydrodynamics 2016年第3期28卷 379-388页

作者： f.GALLERANO G.CANNATA f.LASAPONARA Department of Civil Constructional and Environmental Engineering Sapienza University of Rome

In this paper we propose a new model based on a contravariant integral form of the fully non-linear Boussinesq equations （fNBE） in order to simulate wave transformation phenomena, wave breaking, runup and nearshore currents in computational domains representing the complex morphology of real coastal regions. The above-mentioned contravariant integral form, in which Christoffel symbols are absent, is characterized by the fact that the continuity equation does not include any dispersive term. The Boussinesq equation system is numerically solved by a hybrid finite volume-f＇mite difference scheme. A high-order upwind weighted essentially non-oscillatory （WENO） finite volume scheme that involves an exact Riemann solver is implemented. The wave breaking is represented by discontinuities of the weak solution of the integral form of the non-linear shallow water equations （NSWE）. On the basis of the shock-capturing high order WENO scheme a new procedure, for the computation of the structure of the solution of a Riemann problem associated with a wet/dry front, is proposed in order to simulate the run up hydrodynamics in swash zone. The capacity of the proposed model to correctly represent wave propagation, wave breaking, run up and wave induced currents is verified against test cases present in literature. The results obtained are compared with experimental measures, analytical solutions or alternative numerical solutions. The proposed model is applied to a real case regarding the simulation of wave fields and nearshore currents in the coastal region opposite San Mauro Cilento （Italy）.

关键词： fully non-linear Boussinesq equations contravariant formulation Christoffel symbols upwind WENO scheme wet-dryfronts

An Earthquake Catalogue for El Salvador and Neighboring Central American Countries （1528-2009） and Its Implication in the Seismic Hazard Assessment

在线全文

学校读者我要写书评

暂无评论

Journal of Civil Engineering and Architecture 2013年第8期7卷 1018-1045页

作者： Walter Salazar Lyndon Brown Walter Hemandez Jose guerra Seismic Research Centre The University of the West Indies (UWI) St. Augustine Trinidad and Tobago Earthquake Unit The University of the West Indies (UWI) Mona Kingston Jamaica Geological Survey~General Directorate of Environmental Observatory (DGOA) San Salvador El Salvador Oficina de Planificacien del Area Metropolitana de San Salvador (OPAMSS) San Salvador El Salvador

Merging all available databases, a comprehensive and updated earthquake catalogue for El Salvador and surrounding areas has been compiled, containing a total of 2,584 events for the period 1528-2009, covering the geographic window delimited by the coordinates 11.0°-16.5° N and 85.5°-92.0° W, focal depths of 0.0 to 304 km, and the moment magnitudes in the interval 5.0 〈 Mw 〈 8.1. Events in the catalogue are distributed into six seismogenic sources taking into consideration the tectonic regime affecting E1 Salvador, the interplay and complexities between shallow crustal, intraplate and interface subduction seismicity has been thoroughly investigated, primarily with the aim of developing detail criteria to delimit the seismogenic sources in order to perform a consistent seismic hazard assessment. A uniform hazard spectrum for San Salvador and seismic hazard maps and their uncertainty have been calculated for the horizontal component of ground motion for rock site conditions using zone and zone free methods. The references cited in the article constitute a comprehensive list of sources of information on the tectonics and seismicity of El Salvador and neighboring Central American countries.

关键词： Earthquake catalogue tectonics seismogenic sources Gutenberg-Richter relationships seismic hazard.

Glycemic management in critically ill patients

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

World Journal of Surgical Procedures 2016年第3期6卷 30-39页

作者： Eden A Nohra Jarot J guerra Grant V Bochicchio Section of Acute and Critical Care Surgery Department of SurgeryWashington University in St.Louis

Hyperglycemia associated with critical illness,also called "stress hyperglycemia" or "stress diabetes",is a consequence of many pathophysiologic hormonal responses including increased catecholamines,cortisol,glucagon,and growth *** in multiple biochemical pathways result in increased hepatic and peripheral insulin resistance with an uncontrolled activation of gluconeogenesis and *** has a negative impact on the function of the immune system,on the host response to illness or injury,and on infectious and overall *** degree of glucose elevation is associated with increased disease *** randomized controlled trials including the Van den Berghe study,the NICE-SUGAR trial,VISEP and GLUCONTROL have shown that the control of glucose levels in critically ill patients has implications on outcome and that both hyperglycemia and hypoglycemia are detrimental and should be *** variability has also been shown to be *** glucose control strategies have changed due to the concerns of hypoglycemia and therefore intermediate target glucose control strategies are most often *** patient populations may vary with regards to optimal glucose targets,timing and approach for glucose control,and with regards to the prognostic significance of glucose excursions and ***,surgical,and trauma patients may benefit at different rates from glucose control and the approach may need to be adapted to various medical settings and to correspond to the workflow of health *** modifiers for the success of insulin therapy for hyperglycemia include the methods of nutritional supplementation and exogenous glucose *** research is required to improve insulin protocols for glucose control,to further define glucose targets,and to enhance the accuracy of glucose measuring technologies.

关键词： Hyperglycemia Hypoglycemia Critically ill Intensive care unit Glucose control

formation and Microstructural Characterization of Silicon-modified Aluminide Coating on Nickel-based Superalloy IN738LC

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

材料热处理学报 2004年第05B期25卷 657-660页

作者： f. Shahriari f. Ashrafizadeh A. Monshi Materials engineering department Isfahan University of Technology Isfahan IranMaterials engineering department Isfahan University of Technology Isfahan IranMaterials engineering department Isfahan University of Technology Isfahan Iran

In this investigation, aluminide coatings used to protect industrial components at high temperature and corrosive environments were modified with silicon addition and the microstructural features and formation mechanism were evaluated. The coating on the nickel-based superalloy IN738LC was carried out by a two stage process including siliconizing at first and aluminizing thereafter. Pack cementation siliconizing performed at 950C for 2, 4 and 6 hours in several powder mixtures of Si, A12O3 and NHiCl, then aluminum was diffused into the surface of the specimens by an industrial aluminizing process. The modified coatings were characterized by means of standard metallography, scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction methods. The results show that Si in the coatings mainly presents in the form of secondary phases including Cr3Si, Mo5Si3 and Nii6Ti6Si7, well distributed within the NiAl matrix. The advantages of this two stage modified coating is discussed.

关键词：显微结构 IN738LC 镍超级合金扩散渗碳处理生长机制

Bone marrow-derived mesenchymal stem cells versus adipose-derived mesenchymal stem cells for peripheral nerve regeneration

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2018年第1期13卷 100-104页

作者： Marcela fernandes Sandra Gomes Valente Rodrigo guerra Sabongi Joao Baptista Gomes dos Santos Vilnei Mattioli Leite Henning Ulrich Arthur Andrade Nery Maria José da Silva fernandes Division of Hand and Upper Limb Surgery Department of Orthopedics and Traumatology Universidade Federal de Sao Paulo Sao Paulo Brazil Department of Biochemistry Institute of Chemistry Universidade de Sao Paulo Sao Paulo Brazil Division of Neurosciences Department of Neurology and Neurosurgery Universidade Federal de Sao Paulo Sao Paulo Brazil

Studies have confirmed that bone marrow-derived mesenchymal stem cells （MSCs） can be used for treatment of several nervous system diseases. However, isolation of bone marrow-derived MSCs （BMSCs） is an invasive and painful process and the yield is very low. Therefore, there is a need to search for other alterative stem cell sources. Adipose-derived MSCs （ADSCs） have phenotypic and gene expression profiles similar to those of BMSCs. The production of ADSCs is greater than that of BMSCs, and ADSCs proliferate faster than BMSCs. To compare the effects of venous grafts containing BMSCs or ADSCs on sciatic nerve injury, in this study, rats were randomly divided into four groups： sham （only sciatic nerve exposed）, Matrigel （MG; sciatic nerve injury ＋ intravenous transplantation of MG vehicle）, ADSCs （sciatic nerve injury ＋ intravenous MG containing ADSCs）, and BMSCs （sciatic nerve injury ＋ intravenous MG containing BMSCs） groups. Sciatic functional index was calculated to evaluate the function of injured sciatic nerve. Morphologic characteristics of nerves distal to the lesion were observed by toluidine blue staining. Spinal motor neurons labeled with fluoro-Gold were quantitatively assessed. Compared with sham-operated rats, sciatic functional index was lower, the density of small-diameter fibers was significantly increased, and the number of motor neurons significantly decreased in rats with sciatic nerve injury. Neither ADSCs nor BMSCs significantly improved the sciatic nerve function of rats with sciatic nerve injury,increased fiber density, fiber diameters, axonal diameters, myelin sheath thickness, and G ratios （axonal diameter/fiber diameter ratios） in the sciatic nerve distal to the lesion site. There was no significant difference in the number of spinal motor neurons among ADSCs, BMSCs and MG groups. These results suggest that neither BMSCs nor ADSCs provide satisfactory results for peripheral nerve repair when using MG as the conductor for engraftment.

关键词： nerve regeneration mesenchymal stem cells adipose-derived mesenchmal stem cells sciatic nerve Matrigel sciatic functional index neural regeneration

电子商务、数据分析和驱动成长的公司商业计划书

在线全文

学校读者我要写书评

暂无评论

电子商务、数据分析和驱动成长的公司商业计划书

作者： Andrés Jauregui guerra 上海外国语大学

学位级别：硕士

本项目旨在分析电子商务与数据分析市场,借此打造一家能提供此类服务的公司。此外,论文还介绍了公司将如何利用增长营销思维及其他创新手段,为顾客提供更多价值。如今,电子商务市场利润巨大,但纵观全球,重视该领域的公司并不多,目前只有... 详细信息

本项目旨在分析电子商务与数据分析市场,借此打造一家能提供此类服务的公司。此外,论文还介绍了公司将如何利用增长营销思维及其他创新手段,为顾客提供更多价值。如今,电子商务市场利润巨大,但纵观全球,重视该领域的公司并不多,目前只有约20%的公司针对该领域采取了相关措施。但由于数字化和互联网的普及以及其他因素,未来该行业将继续增长。本项目的重点是:此家拟建的公司如何才能利用好该市场,最终取得成功。该公司将综合数据分析、增长营销等其他创新手段,将其运用于当前的电子商务市场。如今由于这些手段,公司可以获得许多以前无法获得的顾客信息。这些信息有助于改善决策,提高顾客满意度。研究将介绍上述理念,它们将如何影响电子商务市场,以及它们为什么对公司的成功至关重要。之所以选择上述理念,还因为作者虽然目前为软件工程师,但其曾就职于电子营销公司。当前的电子商务环境中需要有此类技能。电子商务前景光明,各个公司正在着手摸索这一领域。项目呈现的各个理念表明,开发电子商务平台,并将其与数据分析、增长营销相结合,有助于提高公司竞争力,获得成功。

关键词：电子商务数据分析增长营销

Identification of Hammerstein-Wiener model with discontinuous input nonlinearity

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2023年第12期66卷 33-47页

作者： A.BROURI f.Z.EL MANSOURI f.Z.CHAOUI C.ABDELAALI f.GIRI ENSAM Moulay Ismail University ENSAM University Mohammed V Normandie Universite

This paper deals with the identification of Hammerstein-Wiener models with an irregular function in the input block. These models comprise a set of linear segments. The linear time invariant(LTI) block may be parametric or nonparametric. The nonlinearity of the output can be any continuous function of arbitrary shape; it is not necessarily assumed to be invertible. Subsequently, sine inputs will be used to identify the system parameters. first, the output nonlinearity is determined by filtering the system output and varying the phase of a given reference sine signal; second, the parameters of the linear block can be determined for any frequency; and finally, the input nonlinearity can be obtained by changing the offset and amplitude of the input sine signal.

关键词： nonlinear systems nonlinear systems identification Hammerstein-Wiener models discontinuous nonlinearities hard nonlinearities

Closed-form solutions for free vibration of rectangular fGM thin plates resting on elastic foundation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2016年第6期32卷 1088-1103页

作者： T. f. Xu Y. f. Xing Institute of Solid Mechanics Beihang UniversityBeijing 100191 China China Academy of Launch Vehicle Technology R&D Center Beijing 100076 China

This article presents closed-form solutions for the frequency analysis of rectangular functionally graded material (fGM) thin plates subjected to initially in-plane loads and with an elastic foundation. Based on classical thin plate theory, the governing differential equations are derived using Hamilton's principle. A neutral surface is used to eliminate stretching-bending coupling in fGM plates on the basis of the assumption of constant Poisson's ratio. The resulting governing equation of fGM thin plates has the same form as homogeneous thin plates. The separation-of-variables method is adopted to obtain solutions for the free vibration problems of rectangular fGM thin plates with separable boundary conditions, including, for example, clamped plates. The obtained normal modes and frequencies are in elegant closed forms, and present formulations and solutions are validated by comparing present results with those in the literature and finite element method results obtained by the authors. A parameter study reveals the effects of the power law index n and aspect ratio a/b on frequencies.

关键词： functionally graded material free vibration Rectangular plate Close form solutions Neutral surface