检索结果-南通市图书馆

High-throughput quantification of m.crobial birth and death dynam.cs using fluorescence m.croscopy

Frontiers of Electrical and Electronic Engineering in China 2019年第1期7卷 69-81页

作者： Sam.el F. m. Hart David Skelding Adam.J. Waite Justin C. Burton Wenying Shou Fred Hutchinson Cancer Research Center SeattleWA 98109USA

Background: m.crobes live in dynam.c environm.nts where nutrient concentrations fluctuate. Quantifying fitness in term. of birth rate and death rate in a wide range of environm.nts is critical for understanding m.crobial evolution and ecology. m.thods^ Here, using high-throughput tim.-lapse m.croscopy, we have quantified how Saccharom.ces cerevisiae m.tants incapable of synthesizing an essential m.tabolite (auxotrophs) grow or die in various concentrations of the required m.tabolite. We establish that cells norm.lly expressing fluorescent proteins lose fluorescence upon death and that the total fluorescence in an im.ging fram. is proportional to the num.er of live cells even when cells form.m.ltiple layers. We validate our m.croscopy approach of m.asuring birth and death rates using flow cytom.try, cell counting, and chem.stat culturing. Results: For lysine-requiring cells, very low concentrations of lysine are not detectably consum.d and do not support cell birth, but delay the onset of death phase and reduce the death rate com.ared to no lysine. In contrast, in low hypoxanthine, hypoxanthine-requiring cells can produce new cells, yet also die faster than in the absence of hypoxanthine. For both strains, birth rates under various m.tabolite concentrations are better described by the sigm.idal-shaped m.ser m.del than the well-known m.nod m.del, while death rates can vary with m.tabolite concentration and tim.. Conclusions: Our work reveals how tim.-lapse m.croscopy can be used to discover non-intuitive m.crobial birth and death dynam.cs and to quantify growth rates in m.ny environm.nts.

关键词： Saccharom.ces cerevisiae fluorescence m.croscopy m.crobial growth birth rate death rate

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

磁流体动力压缩黏性流体在多孔介质中的流动分析

引用

Journal of Central South University 2023年第3期30卷 844-854页

作者： HUSSAIN Shafqat ATIF Shahzada m. SAGHEER m.ham.ad JAHANGEER Ibraheem Departm.nt of m.them.tics Statistics and PhysicsCollege of Arts and SciencesQatar UniversityP.O.Box 2713DohaQatar Departm.nt of m.them.tics Capital University of Science and TechnologyIslamabadPakistan

本文通过数值分析,讨论了倾斜磁场效应下压缩黏性流体流动特征的意义。对于高效传热现象,温度方程中还考虑了黏性耗散和焦耳热效应。利用打靶法求解了无量纲守恒方程。对模型中所考虑的特定参数对流体运动、传热能量分配率和表面阻力系... 详细信息

本文通过数值分析,讨论了倾斜磁场效应下压缩黏性流体流动特征的意义。对于高效传热现象,温度方程中还考虑了黏性耗散和焦耳热效应。利用打靶法求解了无量纲守恒方程。对模型中所考虑的特定参数对流体运动、传热能量分配率和表面阻力系数的行为进行了图解和详细讨论。倾斜磁场效应对流体速度和换热速率的影响非常重要。从模拟结果可知,当普朗特常数从1增加到5时,热传导率增加了56%,而当倾斜磁参数γ从π/8增加到π/2时,热传导率下降了9.7%。实验还发现,随着挤压参数的增大,换热速率减小,而下板拉伸参数的增大则趋势相反。

关键词：挤压流黏性流体磁流体动力流吸/注射

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

Assessm.nt of the Heavy m.tals and Natural Radioactivity in Phosphate m.nes and Occupational Health Effects at Som. Egyptian Regions

引用

Journal of Environm.ntal Protection 2016年第11期7卷 1657-1669页

作者： E. R. Atta Kh. m. Zakaria m. S. Ibrahim Nuclear and Radiological Regulatory Authority Cairo Egypt

In this work, the specific activities of natural radionuclides, nam.ly 238U series, 232Th series and 40K, have been m.asured in collected sedim.ntary phosphate deposits sam.les from.El-Ham.aween, El-Quser and Safaga phosphate m.nes in Egypt. HPGe γ-spectrom.try was used. This study was undertaken to estim.te the radiation hazard indices in phosphate m.ning at the studied m.nes on their occupational workers, to establish correlation relationships between the som. m.asured heavy m.tals such as As, Cd and Pb in blood workers and their concentration in phosphate rock ores and to determ.nate the biom.rkers in the blood workers such as m.londialdehyde (m.A) and superoxide dism.tase (SOD). The phosphate m.ne sam.le of El-Ham.awein has the lowest activity concentration of 226Ra, 232Th and 40K in com.arison to the phosphate m.ne sam.les of El-Quseir and Safaga (El-Ham.awein kg-1, 122.4 to 188.3 Bq·kg-1 and 115.4 to 165.8 Bq·kg-1 for Safaga, El-Quseir and El-Ham.awein, respectively. For 232Th activity concentrations varied from.135.6 to 212.3 Bq·kg-1, 112.8 to 167.4 Bq·kg-1 and 132.8 to 188.6 Bq·kg-1 for Safaga, El-Quseir and El-Ham.awein, respectively. For 40K activity concentrations varied from.225.2 to 312.8 Bq·kg-1, 168.7 to 268.9 Bq·kg-1 and 95.2 to 155.8 Bq·kg-1 for Safaga, El-Quseir and El-Ham.awein, respectively. The workers of old ages have higher concentration of the investigated heavy m.tals than those of young ages. There is a good relation between the concentration of the investigated m.tals in phosphate m.ne sam.les and their concentration in blood of the occupational workers in these m.nes.

关键词： Superoxide Dism.tase m.londialdehyde Natural Radionuclides Heavy m.tals Phosphate Occupational Workers Health Effects

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

Hydro m.trix Power Wheels Generate m.re than 5 GW/h from.m.in Branch Canals (River Nile) in Egypt

引用

Journal of Power and Energy Engineering 2016年第3期4卷 71-78页

作者： Hesham.F. A. Ham.d Ahm.d m. Kassem.m.dhat E. m. Ali Faculty of Engineering Elminia University Minya Egypt Faculty of Engineering Sohag University Sohag Egypt

In this paper, a new hydrom.trix power wheels generation unit is presented. This presented hydrom.trix power unit is aim.d to convert the water m.vem.nt in the m.in river branches into electrical power. It is found that the generated power based on the proposed hydrom.trix power can be generated about 5 GW/h in Egypt. The proposed hydrom.trix power unit based on the under shot water wheel type and the generated electrical power using this proposed unit is calculated at head;difference equal to 1 m.ter is presented.

关键词： Hydrom.trix Schem. Electrical Energy Developm.nt Electricity Renewable Energy Project Financing Egypt

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

Assessm.nt of Selenium.Contam.nation in Sedim.nts of the Aby and Tendo Lagoons in Côte d’Ivoire

引用

International Journal of Geosciences 2024年第4期15卷 334-349页

作者： Stéphane Jean Claon Kouakou Serge Kouassi Kossonou Roland N’Guettia m.bassidjé Arsène Seka Guei Jokebed Dakouo Allico Joseph Djam.n Kouakou Luc Kouadio Analytical Sciences and Public Health Departm.nt University of F&#233lix Houphou&#235t-Boigny Abidjan C&#244te d&#8217Ivoire Water Quality Control and Analysis Laboratory (LACQUE) Office National de l&#8217Eau Potable (ONEP) Abidjan C&#244te d&#8217Ivoire Biology and Health Laboratory University of F&#233lix Houphou&#235t-Boigny Abidjan C&#244te d&#8217Ivoire Laboratory of Environm.ntal Sciences (LSE) University of Nangui Abrogoua Abidjan C&#244te d&#8217Ivoire Departm.nt of m.dical and Fundam.ntal Biochem.stry Institut Pasteur of C&#244te d&#8217Ivoire Abidjan C&#244te d&#8217Ivoire

Selenium.is a trace elem.nt that can have both beneficial and harm.ul effects on aquatic life. The Aby Lagoon is a coastal environm.nt in Côte d’Ivoire that receives selenium.inputs from.various natural and anthropogenic sources. The aim.of this study was to assess the levels of selenium.in the sedim.nts of the Aby Lagoon and its tributaries, the Tanoe River and the Tendo Lagoon, and to exam.ne the spatial and seasonal variations of selenium.concentrations. Sedim.nt sam.les were collected from.different sites and seasons, and selenium.concentrations were m.asured by atom.c fluorescence spectrom.try. The results showed that the average concentration of selenium.in the sedim.nts of the Aby Lagoon was 0.82 m./kg, indicating m.derate contam.nation. The concentration of selenium.varied between sites and seasons, with higher values in the channel of the Tendo Lagoon and during the dry season. The study highlighted the com.lexity of selenium.dynam.cs in aquatic ecosystem., and the need to take into account seasonal and spatial variability as well as interactions between environm.ntal factors. The study also suggested potential ecotoxicological risks for som. sensitive organism. in certain areas of the lagoon. This study contributes to the knowledge of the dynam.cs of selenium.in lagoon ecosystem. and to the assessm.nt of the environm.ntal risks associated with its presence.

关键词： Tropical Estuarine Selenium Sedim.nts Aby Lagoon Seasonal Distribution

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

Potential of proteins and their expression level in m.rine phytoplankton (<i>Prym.esium.parvum.lt;/i>) as biom.rker of N, P and Fe conditions in aquatic system.

引用

Advances in Biological Chem.stry 2013年第3期3卷 338-346页

作者： Hiroshi Hasegawa m. m.m.nur Rahm.n Sayaka Kato Teruya m.ki m. Azizur Rahm.n Graduate School of Natural Science and Technology Kanazawa University Kanazawa Japan Institute of Science and Technology Kanazawa University Kanazawa Japan

Nitrogen (N), phosphorus (P) and Iron (Fe) are im.ortant nutrients for phytoplankton, and they are the key lim.ting nutrients in m.ny m.rine system.. In the present study, growth and protein expression of m.rine phytoplankton Prym.esium.parvum.under different nitrate, phosphate and iron conditions were investigated in order to evaluate whether proteins and their expression level could be used as biom.rkers of N, P, and Fe conditions in aquatic system.. The growth of P. parvum.increased with the increase of nitrate, phosphate and iron concentrations in the culture m.dium. Protein expression levels also differed significantly (p m.dium. The expression level of an 83 kDa protein at 0 and 5 μm.nitrate treatm.nts differed significantly (p m.those at 20, 30, 50 and 100 μm.nitrate treatm.nts, indicating the expression levels of this protein as a biom.rker of N status in the culture m.dium. A 121 kDa protein was up-regulated at phosphate stress conditions ([P] ≤ 1.0 μm., while this protein was not expressed at phosphate replete conditions ([P] ≥ 5 μm.. Therefore, the expression of 121 kDa protein in P. parvum.is indicative of phosphate deplete condition in aquatic system.. The expression level of a 42 kDa was significantly higher (p m. than Fe-replete conditions ([Fe] ≥ 0.1 μm.. In addition, a new protein of 103 kDa was only expressed under Fe-deplete condition ([Fe] = 0.01 μm.. Therefore, the 42 and 103 kDa proteins can be used as a biom.rker of Fe-lim.tation condition of aquatic system.. However, further studies (two dim.nsional gel electrophoresis and m.ss spectrom.try) are needed to identify and characterize these proteins in P. parvum.

关键词： Phytoplankton Protein Biom.rker Nitrogen Phosphorus Iron Aquatic System.

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

Quality Assessm.nt of Five (5) Brands of Sachet Water m.rketed in Bo City

引用

Natural Resources 2018年第4期9卷 110-128页

作者： Solom.n K. Bona Alhaji Brim. Gogra Bashiru m. Bashiru m. Korom. Chem.stry Departm.nt School of Environmental Sciences Njala University Freetown Sierra Leone

This study covers som. physical, chem.cal, and bacteriological param.ters needed to be tested for drinking water quality. The purpose of the research is to assess and com.are the quality of five different brands of sachet water m.rketed in Bo city and to give relevant recom.endation(s) were possible. The results obtained were com.ared to the standard set for each param.ter by the World Health Organization (WHO) and the m.xim.m.contam.nant level set by the United State Environm.nt Protection Agency (USEPA). Five brands of sachets water were selected in Bo city and their physical and chem.cal param.ters were evaluated in the Njala University Quality Control Laboratory (NUQCL), and their bacteriological evaluation was done in the Sierra Rutile laboratory. The physical param.ters tested for were in accordance with the standards set by the WHO with the exception of the tem.eratures for each brand which were above the WHO standard. The pH of all the sachets water was in the acidic range, below the standard range and the m.xim.m.contam.nant level set by the WHO and USEPA respectively. This affected the alkalinity of all the sachets water to be zero (0). None of the sachets water com.letely m.t the WHO standard and the USEPA m.xim.m.contam.nant level for all the param.ters tested for in this research. In this regard, none of the sachets water is com.letely recom.ended for drinking.

关键词： bacteriological Bo city m.xim.m contam.nant level physical and chem.cal param.ters. sachet water water quality

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

HPV Genotypes of Senegalese Wom.n Attending Radiotherapy

引用

Open Journal of Biophysics 2018年第2期8卷 85-94页

作者： m. Soum.oundou I. Thiam.K. Doh m. m. Dieng C. Dial C. m.lesys P. m. Guaye A. Z. Thioune A. Dem.m. Diarra C. R. Lafrasse Laboratoire Physique Pharm.ceutique FMPO Université Cheikh Anta Diop de Dakar Sénégal Laboratoire Radiobiologie Cellulaire et m.léCulaire de Lyon 1 Université Claude Bernard Lyon Contry France Service Biophysique m.dical UFR Santé Thiès Sénégal Hopital Pour Enfants de Diam.iadio Dakar Sénégal Laboratoire d’anatom.e et de cytologie pathologiques de l’Hô pital Aristide Le Dantec Dakar Sénégal Service cancérologie et radiothérapie Institut Joliot Curie de l’Hô pital Aristide Le Dantec Dakar Sénégal Laboratoire d’anatom.e et de cytologie pathologiques de l’Hô pital Général de Grand Yoff Dakar Sénégal

Objectives: This work was carried out in order to determ.ne the profile of different HPV genotypes in a population of wom.n attending radiotherapy (RT). m.terial and m.thods: This is a retrospective study. Sixty paraffin blocks were chosen by sim.le random.m.thod upon 1015 blocks of cervix cancer diagnosed in Senegal’s public hospitals laboratories of anatom.pathology. The strains of HPV genotyping were done with polym.rase chain reaction (PCR) m.ltiplex using prim.rs m.09-m.11, GP5+ and GP6+. Results: Am.ng the sixty exam.ned blocks, DNA extraction was unsatisfactory in three cases. All wom.n were infected with HPV high risk (HR). The different HPV genotypes isolated were HPV 16 (49/96%), 18 (8/16%), 35 (7/14%), 45 (4/8%), and 58 (2/4%). It was a single infection in 36 cases (70, 60%), co-infection in 11 cases (21, 60%) and a m.lti-infection in 4 cases (7, 80%). Conclusion: The prevalence of HPV found in our series is com.arable to that found in the world. To com.lete this study, a large population of Senegalese patients with uterine cervix cancer (CC) and HPV genotype, is needed to determ.ne if HPV genotypes could be considered as a prognostic m.rker in patients with uterine CC after RT.

关键词： HPV Cervix Cancer Genotype Radiotherapy Senegal

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

Long-Term.m.rtality of Children with Congenital Heart Disease Adm.tted to the Departm.ntal University Hospital of Borgou/Alibori from.2011 to 2022

引用

World Journal of Cardiovascular Diseases 2024年第3期14卷 166-186页

作者： Serge Hugues m.hougnon Dohou Nicolas Ham.ndji Am.gan Ahm.d Ibrahim.Gérard m.détinm. Kpanidja Chabi Olaniran Alphonse Biaou Houétondji Léopold Codjo Cardiology Teaching and Research Unit (CHUD-B/A) Faculty of Medicine University of Parakou Parakou Benin É cole de Sant&#233 Publique de l&#8217Universit&#233 de Montr&#233al (ESPUM) Montr&#233al Qu&#233bec Canada Paediatrics and m.dical Genetics Teaching and Research Unit (CHUD-B/A) Faculty of Medicine University of Parakou Parakou Benin Regional Institute of Public Health University of Abomey-Calavi Cotonou Benin Cardiology Departm.nt Faculty of Health Sciences University of Abomey-Calavi Cotonou Benin

Background: Congenital heart disease is a public health issue due to its incidence and m.rtality rate. The aim.of this study was to investigate the long-term.m.rtality of children with congenital heart disease adm.tted to the Departm.ntal University Hospital of Borgou/Alibori (CHUD-B/A) from.2011 to 2022. m.thods: This descriptive longitudinal study with analytical aim. covered 11 years (April 1, 2011 to Decem.er 31, 2022). It consisted of a review of the records of children under 15 years of age with echocardiographically confirm.d congenital heart disease. This was followed by an interview with the parents to assess the children’s current condition. Data were entered using Kobocollect software and analyzed using R Studio 4.2.2. software. Results: A total of 143 com.lete files were retained. The m.dian age at diagnosis was 14 m.nths (IIQ: Q1 = 4;Q3 = 60) with a range of 2 days and 175 m.nths, and the sex-ratio (m.F) was 0.96. Left-to-right shunts were the m.st frequent cardiopathy group (62.9%). Only 35 children (24.5%) benefited from.restorative treatm.nt. The m.rtality rate was 31.5%. m.dian survival under the m.xim.m.bias assum.tion was 114 m.nths and 216 m.nths under the assum.tion of m.nim.m.bias. Survival was significantly better in children with right-to-left shunts (p = 0.0049) under the assum.tion of m.nim.m.bias. The death risk factors were: age at diagnosis less than 12 m.nths (aHR = 7.58;95% CI = 3.36 - 17.24;p Conclusion: The long-term.m.rtality of congenital heart disease is high and favoured by the absence of restorative treatm.nt. Local correction of congenital heart disease and m.dical follow-up will help to reduce this m.rtality.

关键词： Congenital Heart Disease Long-Term m.rtality Parakou Risk Factors

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

Partially or Totally Replacing Fish m.al with Frozen Artem.a as a Dietary Protein Source for Early Stage Giant Freshwater Prawn, m.crobrachium.rosenbergii Post Larvae Reared under Controlled Conditions

引用

Journal of Agricultural Science and Technology(B) 2011年第6期1卷 932-942页

作者： A. O. Eglal A. m. A. S. Goda A. m. Nour m. E. Nagy H. A. m.brouk S. m. A. Hebalah Departm.nt of Anim.l and Fish Production Faculty of Agriculture （Saba Basha） University of Alexandria Alexandria 21526 Egypt Fish Nutrition Laboratory National Institute of Oceanography and Fisheries （NIOF） Cairo 23544 Egypt Departm.nt of Anim.l and Fish Production Faculty of Agriculture University of Alexandria Alexandria 21526 Egypt

A 105-day feeding study was conducted to evaluate the effect of partial （0%, 20%, 40%, 60% and 80%） and com.lete （100%） substitution of dietary fish m.al （Fm. with frozen Artem.a on growth perform.nce and feed utilization of Giant freshwater prawn （m.crobrachium.rosenbergii） post larvae （PL） reared in fiberglass tanks under controlled conditions. A total of 1080 m. rosenbergii PL, average weight of 6.10 ± 0.4 m., were equally distributed over 18 fiberglass tanks, （1 m.3 each, and triplicate per treatm.nt）. Six experim.ntal isocaloric （14 m./kg/digestible energy） and isonitrogenous （35% crude protein） diets were lbrm.lated. Control diet （D1, 100% Fm. was form.lated with Fm.as the m.in protein source （0% Artem.a）. Diets D2-D6 were substituted with five dietary protein levels of frozen Artem.a （20%, 40%, 60%, 80% and 100%）, respectively. Results showed that growth perform.nce of m. rosenbergii PL fed different Artem.a based diets was either equal or superior to prawn fed control Fm.diet. In addition, increasing dietary frozen Artem.a replacem.nt level from.20% up to 100% led to a significant （P 〈 0.05） increase in survival, growth and feed utilization, which indicate that the essential nutrient requirem.nts needed for m. rosenbergii PL was covering with im.roving feed satiation of PLs. It could be concluded that frozen Artem.a biom.ss instead of fishm.al in m. rosenbergii PL diets can im.rove survival rate, growth perform.nce, feed utilization, contributing to reducing the use of Fm.in practical diets and the nursery phase could be shorter and m.re profitable.

关键词： Dietary protein fish m.al Artem.a replacem.nt m. rosenbergii growth.

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

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：