检索结果-南通市图书馆

Normozoospermic versus teratozoospermic domestic cats： differential testicular volume, sperm morphometry, and subpopulation structure during epididymal maturation

引用

Asian Journal of Andrology 2016年第6期18卷 871-878页

作者： Miguel Angel Gutierrez-Reinoso Manuel Garcia-Herreros National Secretariat of Higher Education Science Technology and Innovation (SENESCYT) Quito Ecuador

Teratozoospermia （〈40% morphologically normal spermatozoa/ejaculate） is a frequent phenomenon in feline species. This research was carried out to study the possible differences in testicular volume, differential sperm morphometric traits, and potential differences regarding the sperm subpopulational structure during epididymal sperm maturation in teratozoospermic feline donors. Epididymal sperm samples were collected from the caput （R1）, corpus （R2）, and cauda （R3） epididymidis in two donor groups （N： normozoospermic; T： teratozoospermic）. Aliquots were assessed for concentration, viability, motility, and acrosomal integrity. Sperm morphometric descriptors from CASA-Morph analysis were analyzed by the Principal Component Analysis （PCA） and clustering analyses. Irrespective of the group analyzed, PCA revealed two Principal Components （PCs） for each epididymal region explaining more than the 93% of the variance. Surprisingly, the number of subpopulations remained constant in regions R1-R2-R3 irrespective of the donor group analyzed. However, the distribution of these subpopulations was found to be structurally different and strongly influenced by the epididymal region and the donor group. In conclusion, testicular morphometry and the sperm subpopulation structure were different in N and T donors. The alterations in subpopulations during epididymal maturation could be used as a potential clinical indicator of teratozoospermic individuals since an important influence of teratozoospermia on sperm subpopulation structure has been demonstrated.

关键词： epididymis feline sperm morphometry sperm subpopulations teratozoospermia testicular volume

来源：

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

Sperm subpopulations in avian species： a comparative study between the rooster （Gallus domesticus） and Guinea fowl （Numida meleagris）

引用

Asian Journal of Andrology 2016年第6期18卷 889-894页

作者： Manuel Garcia-Herreros National Secretariat of Higher Education Science Technology and Innovation (SENESCYT) Quito Ecuador

The main aims of this research were to study possible differences in objective morphometric sperm characteristics, establish normative sperm morphometry standards, and evaluate the presumed different subpopulation distribution of avian spermatozoa from the rooster （Gallus domesticus） and Guinea fowl （Numida meleagris） as model avian species. Seventy-two ejaculates （36 per species studied） were obtained manually, following a training period involving gently combined dorso-abdominal and lumbo.sacral massage of the birds. Ejaculates were processed for volume, sperm concentration, viability, motility, and morphology. Moreover, samples were submitted for sperm morphometric assessment using objective Computer-Assisted Semen Analysis for Morphometry （CASA-Morph） methods, with sperm morphometric descriptors evaluated by Principal Component Analysis （PCA） and multivariate clustering analyses. There were several differences observed between the avian species in values obtained for ejaculate volume and sperm concentration （P 〈 0.001）. Irrespective of species, PCA revealed two Principal Components （PCs） explaining more than 80% of the variance. In addition, the number of subpopulations differed with species （three and five subpopulations for rooster and Guinea fowl, respectively）. Moreover, the distribution of the sperm subpopulations was found to be structurally different between species. In conclusion, our findings from using CASA-Morph methods indicate pronounced sperm morphometric variation between these two avian species. Because of the strong differences observed in morphometric parameter values and their subpopulation distribution, these results suggest that application of objective analytical methods such as CASA-Morph could substantially improve the reliability of comparative studies and help establish valid normative sperm morphological values for avian species.

关键词： Gallus domesticus Numida meleaEris principal component analysis sperm morphometry sperm subpopulations

来源：

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

national/Global Synergy in the Development of higher education and Science in China since 1978

引用

Frontiers of education in China 2018年第4期13卷 486-512页

作者： Simon MARGINSON ESRC/OFSRE Centre for Global higher education Department of EducationUniversity of OxfordOxfordOX13JAUK

The paper reviews the rapid development of higher education and science in China in the last forty years.It discusses the conditions and strategies of that development,including the ways that it embodies a distinctive Chinese approach to higher education.In particular,the paper reflects on the policies whereby China coordinated with globalization in higher education and science after 1978,in building national capacity and global influence.Scale,nation-state policy goals and accelerated investment on their own are necessary but not sufficient(otherwise Saudi Arabia’s research universities would be stronger than they are).The effective national/global synergy developed by China,made possible by the international openness and part-devolution to science communities that was implemented in the Deng Xiaoping era,has been crucial in the rapid rise of China’s universities and science.This national/global synergy-and its potentials,tensions and limits-in turn has determined the nature of the achievement and will shape its future evolution.

关键词： China higher education universities research science globalization devolution Deng Xiaoping

来源：

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

Deregulated miRNA clusters in ovarian cancer:Imperative implications in personalized medicine

引用

Genes & Diseases 2022年第6期9卷 1443-1465页

作者： Amoolya Kandettu Divya Adiga Vasudha Devi Padmanaban SSuresh Sanjiban Chakrabarty Raghu Radhakrishnan Shama Prasada Kabekkodu Department of Cell and Molecular Biology Manipal School of Life SciencesManipal Academy of Higher EducationManipalKarnataka 576104India Department of Pharmacology Centre for Cardiovascular PharmacologyMelaka Manipal Medical CollegeManipal Academy of Higher EducationManipal CampusManipalKarnataka 576104India School of Biotechnology National Institute of TechnologyCalicutKerala 673601India Department of Oral Pathology Manipal College of Dental SciencesManipal Academy of Higher EducationManipalKarnataka 576104India Center for DNA Repair and Genome Stability(CDRGS) Manipal Academy of Higher EducationManipalKarnataka 576104India

Ovarian cancer(OC)is one of the most common and fatal types of gynecological cancer.OC is usually detected at the advanced stages of the disease,making it highly lethal.miRNAs are single-stranded,small non-coding RNAs with an approximate size ranging around 22 nt.Interestingly,a considerable proportion of miRNAs are organized in clusters with miRNA genes placed adjacent to one another,getting transcribed together to result in miRNA clusters(MCs).MCs comprise two or more miRNAs that follow the same orientation during transcription.Abnormal expression of the miRNA cluster has been identified as one of the key drivers in OC.MC exists both as tumor-suppressive and oncogenic clusters and has a significant role in OC pathogenesis by facilitating cancer cells to acquire various hallmarks.The present review summarizes the regulation and biological function of MCs in OC.The review also highlights the utility of abnormally expressed MCs in the clinical management of OC.

关键词： Diagnosis Drug resistance miRNA clusters Ovarian cancer Prognosis Regulation

来源：

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

Physicochemical properties of Li_(3)Ba_(2)La_(3)(MoO_(4))_(8):Eu,Tb red-emitting phosphor for solid state white lamps

引用

稀土学报:英文版 2023年第9期41卷 1279-1287,I0001页

作者： Kora Lu Rojas Baldivia Gustavo A.Hirata Center for Scientific Research and higher education of Ensenada Ensenada Baja California 22860Mexico Center for Nanoscience and Nanotechnology National Autonomous University of Mexico EnsenadaBaja Califomia 22860Mex

In this work,combustion synthesis was used for the first time to fabricate a phosphor material with red emission for applications in solid-state white-light lamps.We synthesized a material with emission wavelength at λ_(em)=617 nm,excited under long UV-blue wavelength based on Eu^(3+),Tb^(3+)-activated molybdates Li_(3)Ba_(2)(La_(1-x-y)Eu_(x)Tb_(y))_(3)(MoO_(4))_(8) with 0 ≤ x ≤1 and 0 ≤ y ≤ 1.A series of powder samples were produced by the combustion method and post-annealed at 800℃ in air.The crystalline phase formation was investigated by X-ray diffraction,which reveals the monoclinic C2/c(15) space group.It is observed that crystalline structure and morphology are preserved when the host lattice is doped with Eu^(3+) or Tb^(3+) single ions and co-doped with both ions at different doping concentrations.A detailed characterization by scanning electron microscopy(SEM) and transmission electron microscopy(TEM)shows a similar morphology in all samples:rather large(1-7 μm) agglomerate particles with irregular shapes and surrounded by smaller nanoparticles of 50 nm in size.UV-visible absorption spectra confirm the presence of Eu^(3+) and Tb^(3+) ions.The luminescent properties of the obtained phosphors were studied in detail.Cathodoluminescence measurements indicate that the best emission intensity is for Eu^(3+):Tb^(3+)doping ratios of 80:0,90:0 and 20:80.On the other hand,samples with 80:0,60:40,and 20:80 doping ratios show the highest intensity in a detailed photoluminescence analysis and they exhibit the highest quantum yield values.A complete and efficient energy transfer from the sensitizer Tb^(3+) to the activator Eu^(3+) is observed in all co-doped phosphors post-annealed at 800℃ for 4 h.Thus,the Li_(3)Ba_(2)La_(3)(MaO_(4))_(8):Eu^(3+),Tb^(3+) materials fabricated by combustion synthesis are excellent phosphors for being applied as red-emitting component in solid-state white-light lamps due to an improved color rendering index(CRI) that can be obtained under long UV-blue excitation wavelengths.

关键词： Molybdate Europium Terbium Luminescence Phosphor-converted LED Rare earths

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimization algorithms and intelligent techniques on electrical discharge machining process

引用

International Journal of Modeling, Simulation, and Scientific Computing 2021年第4期12卷 12-40页

作者： C.S.Shyn R.Rajesh Noorul Islam Centre for higher education Tamil Nadu India

Electrical Discharge Machining (EDM) is considered as the much traditional, adaptableand unconventional machining process that is proficient in generating complicated structures. Further, it is self-sufficient over the mechanical properties of workpiece materialsonly if it is conductive. The viability of the EDM process regarding the application typesmight get considerably improved with the constant enhancement in the personificationof numerical control and the metal removal efficacy. This survey intends to make a reviewof 65 papers related to the optimization and modeling of EDM process machining. Theanalysis is thus made with regards to the following factors like Al alloy composite in DieShrinking EDM, Optimization and Al metal matrix composites. Particularly, the hybridoptimization models in various papers are analyzed concerning their logic. Further, thealgorithmic and parametric analysis is also made with the contributed papers. Finally,the research gaps and challenges in this EDM processing are discussed, which wouldpave the way for efficient research works in this area.

关键词： Electric discharge machining aluminium alloy metal matrix composite neural network optimization

来源：

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

Chiral nanoporous networks featuring various chiral vertices from an achiral molecule on Ag(100)

引用

Nano Research 2022年第4期15卷 3753-3762页

作者： Dong Han Tao Wang Jianmin Huang Xingyu Li Zhiwen Zeng Junfa Zhu national Synchrotron Radiation Laboratory Department of Chemical Physics and Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education InstitutesUniversity of Science and Technology of ChinaHefei 230029China

Chiral nanoporous nanoarchitectures exhibit potential applications in various fields including chiral separation,sensing and catalysis.Two-dimensional(2D)supramolecular chemistry offers novel methods to build chiral nanoporous networks from achiral molecules.Herein,we report a series of chiral nanoporous networks built by an achiral precursor molecule via a stepwise annealing strategy on Ag(100).The nanoporous network morphologies and structural details are characterized by high-resolution scanning tunneling microscopy(STM).It is revealed that all vertices within networks are chiral.These chiral vertices are either dimeric,trimeric,or tetrameric.The connection of these chiral vertices gives rise to diverse chiral nanopores with varying shapes and sizes.A strict chirality correlation between nanopores and their vertices is determined.Specifically,enantiomeric vertices of one-pair nanopore enantiomers are always in identical type but opposite handedness.This work serves as a model to investigate the influence of vertex chirality on nanopore chirality of a supramolecular matrix.The attained chiral nanopores could potentially be utilized as templates for surface reaction,chiral recognition,etc.The mirror-symmetric silver adatoms clusters dictated by chiral nanopore are discerned.

关键词： two-dimensional chirality chiral nanoporous networks chiral vertices scanning tunneling microscopy

来源：

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

Emerging memristors and applications in reservoir computing

引用

Frontiers of physics 2024年第1期19卷 219-239页

作者： Hao Chen Xin-Gui Tang Zhihao Shen Wen-Tao Guo Qi-Jun Sun Zhenhua Tang Yan-Ping Jiang School of Physics and Optoelectronic Engineering Guangdong University of TechnologyGuangzhou Higher Education Mega CenterGuangzhou 510006China

Recently, with the emergence of ChatGPT, the field of artificial intelligence has garnered widespread attention from various sectors of society. Reservoir Computing (RC) is a neuromorphic computing algorithm used to analyze time-series data. Unlike traditional artificial neural networks that require the weight values of all nodes in the trained network, RC only needs to train the readout layer. This makes the training process faster and more efficient, and it has been used in various applications, including speech recognition, image classification, and control systems. Its flexibility and efficiency make it a popular choice for processing large amounts of complex data. A recent research trend is to develop physical RC, which utilizes the nonlinear dynamic and short-term memory properties of physical systems (photonic modules, spintronic devices, memristors, etc.) to construct a fixed random neural network structure for processing input data to reduce computing time and energy. In this paper, we introduced the recent development of memristors and demonstrated the remarkable data processing capability of RC systems based on memristors. Not only do they possess excellent data processing ability comparable to digital RC systems, but they also have lower energy consumption and greater robustness. Finally, we discussed the development prospects and challenges faced by memristors-based RC systems.

关键词： reservoir computing memristor resistive switching artificial synapse neuromorphic computing

来源：

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

搅拌铸造金红石增强AA6061基复合材料的显微组织和力学性能（英文）

引用

Transactions of Nonferrous Metals Society of China 2019年第11期29卷 2229-2236页

作者： Subramanya R.PRABHU Arun K.SHETTIGAR Mervin A.HERBERT Shrikantha S.RAO Department of Mechanical Engineering National Institute of Technology KarnatakaSurathkalIndia Department of Mechatronics Engineering Manipal Institute of TechnologyManipal Academy of Higher EducationManipalIndia

采用一种新型的双级搅拌铸造法制备铝基复合材料(AMCs)。将不同质量分数的金红石颗粒(1%,2%,3%和4%)分散于AA6061基体中,研究复合材料的密度、抗拉强度、硬度和显微组织。双级搅拌铸造法使金红石颗粒均匀分布于AA6061基体中,AMCs的性能... 详细信息

采用一种新型的双级搅拌铸造法制备铝基复合材料(AMCs)。将不同质量分数的金红石颗粒(1%,2%,3%和4%)分散于AA6061基体中,研究复合材料的密度、抗拉强度、硬度和显微组织。双级搅拌铸造法使金红石颗粒均匀分布于AA6061基体中,AMCs的性能相较于母材得到提高。与未增强的母材相比,金红石增强的AMCs具有较高的抗拉强度和硬度,且增强效果随金红石颗粒含量的增加而增加。然而,当金红石颗粒质量分数超过3%时,样品的抗拉强度降低。与母材相比,3%金红石颗粒增强的AMCs的硬度和抗拉强度分别提高了36%和14%。

关键词： AA6061金红石复合材料双极搅拌铸造显微组织力学性能断口形貌

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Synthesis of hierarchical porous carbon with high surface area by chemical activation of(NH_(4))_(2)C_(2)O_(4) modified hydrochar for chlorobenzene adsorption

引用

Journal of Environmental Sciences 2023年第4期126卷 123-137页

作者： Jie Wen Zewei Liu Hongxia Xi Bichun Huang School of Environment and Energy South China University of TechnologyGuangzhou Higher Education Mega CentreGuangzhou 510006China School of Chemistry and Chemical Engineering South China University of TechnologyGuangzhou 510640China The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of EducationSouth China University of TechnologyGuangzhou Higher Education Mega CentreGuangzhou 510006China

In this work,hydrothermal technique combined with KOH activation were employed to develop a series of porous carbons (NPCK-x) using tobacco stem as a low-cost carbon source and (NH_(4))_(2)C_(2)O_(4)as a novel nitrogen-doping agent.Physicochemical properties of NPCK-x were characterized by Brunauer-Emmett-Teller,field emission scanning electron microscopy,X-ray diffraction,Raman microscope,elemental analysis,and X-ray photoelectron spectroscopy.Results showed that the NPCK-x samples possessed large surface areas (maximum:2875 m^(2)/g),hierarchical porous structures,and high degree of disorder.N-containing functional groups decomposed during activation process,which could be the dominant reason for appearance of abundant mesopores and well-developed pore structure.Dynamic chlorobenzene adsorption experiments demonstrated that carbon materials with(NH_(4))_(2)C_(2)O_(4)modification exhibited higher adsorption capacity (maximum:1053 mg/g) than those without modification (maximum:723 mg/g).The reusability studies of chlorobenzene indicated that the desorption efficiency of (NH_(4))_(2)C_(2)O_(4)modified porous carbon reached90.40%after thermal desorption at 100℃ under N2atmosphere.Thomas model fitting results exhibited that the existence of mesopores accelerated the diffusion rate of chlorobenzene in porous carbon.Moreover,Grand Canonical Monte Carlo simulation was conducted to verify that micropores with pore sizes of 1.2–2 nm of the optimized porous carbon were the best adsorption sites for chlorobenzene and mesopores with pore sizes of 2–5 nm were also highly active sites for chlorobenzene adsorption.

关键词： Tobacco stem Hierarchical porous carbon N-containing groups Dynamic adsorption Chlorobenzene

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：