检索结果-南通市图书馆

色谱 2012年第11期30卷 1194-1202页

作者： André Moreni LOpES Jorge Sánchez ROMEU Rolando Páez MEIRELES Gabriel Marquez pERERA rolando perdomo MORALES Adalberto pESSOA Lourdes Zumalacárregui CáRDENAS Department of Biochemical and pharmaceutical Technology School of Pharmaceutical SciencesUniversity of So Paulo(FCF/USP) purification Development Department Center for Genetic Engineering and Biotechnology(CIGB) Center for pharmaceuticals Research and Development(CIDEM) Higher polytechnic Institute José Antonio Echeverría(CUJAE)

Endotoxins(also known as lipopolysaccharides(LpS)) are undesirable by-products of recombinant proteins,purified from Escherichia coli.LpS can be considered stable under a wide range of temperature and pH,making their removal one of the most difficult tasks in downstream processes during protein purification.The inherent toxicity of LpS makes their removal an important step for the application of these proteins in several biological assays and for a safe parenteral administration.Immobilized metal affinity chromatography(IMAC) enables the affinity interactions between the metal ions(immobilized on the support through the chelating compound) and the target molecules,thus enabling high-efficiency separation of the target molecules from other components present in a mixture.Affinity chromatography is applied with Ca2+-iminodiacetic acid(IDA) to remove most of the LpS contaminants from the end product(more than90%).In this study,the adsorption of LpS on an IDA-Ca2+ was investigated.The adsorption Freundlich isotherm of LpS-IDA-Ca2+ provides a theoretical basis for LpS removal.It was found that LpS is bound mainly by interactions between the phosphate group in LpS and Ca2+ ligands on the beads.The factors such as pH(4.0 or 5.5) and ionic strength(1.0 mol/L) are essential to obtain effective removal of LpS for contaminant levels between endotoxin' concentration values less than100 EU/mL and 100 000 EU/mL.This new protocol represents a substantial advantage in time,effort,and production costs.

关键词： immobilized metal affinity chromatography(IMAC) lipopolysaccharides(LpS) endotoxin removal recombinant proteins isotherms protein purification

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

Analysis of the geometrical dependence of auxetic behavior in reentrant structures by finite elements

引用

Acta Mechanica Sinica 2016年第2期32卷 295-300页

作者： V.H.Carneiro H.puga J.meireles Department of Mechanical Engineering University of Minho

Materials with a negative poisson＇s ratio（pR）are called auxetics;they are characterized by expansion/contraction when tensioned/compressed.Given this counterintuitive behavior,they present very particular characteristics and mechanical behavior.Geometrical models have been developed to justify and artificiall reproduce such materials＇ auxetic behavior.The focus of this study is the exploration of a reentrant model by analyzing the variation in the pR of reentrant structures as a function of geometrical and base material parameters.It is shown that,even in the presence of protruding ribs,there may not be auxetic behavior,and this depends on the geometry of each reentrant structure.Values determined for these parameters can be helpful as approximate reference data in the design and fabrication of auxetic lattices using reentrant geometries.

关键词： Auxetic poisson’s ratio Reentrant Finite element analysis Elasticity

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

Epigenetic marks are modulated by gender and time of the day in the hippocampi of adolescent rats:a preliminary study

引用

Neural Regeneration Research 2018年第12期13卷 2160-2163页

作者： Viviane Rostirola Elsner Laura Reck Cechinel Louisiana Carolina Ferreira de meireles Karine Bertoldi Ionara Rodrigues Siqueira programa de pós-Graduacao em Ciências Biológicas:Fisiologia Instituto de Ciências Básicas da SaúdeUniversidade Federal do Rio Grande do Sul programa de pós-Graduacao em Biociências e Reabilitacao Centro Universitário Metodista-IPA Curso de Fisioterapia Centro Universitário Metodista-IPA

Although the involvement of gender in epigenetic machinery in peripheral tissues during the neonatal period has been suggested, the gender-related epigenetic profile of brain areas during the adolescent period is rarely exploited. Furthermore, the influence of time of day on hippocampal acetylation marks has been demonstrated in young adult and aged rats; however, there are no studies reporting epigenetic changes in the adolescent period. Therefore, this study aimed to investigate the effects of gender on hippocampal DNA methyltransferase 1 content and histone deacetylase（HDAC） activity of adolescent rats at different time points, specifically early morning and afternoon. Both epigenetic markers increased significantly in the hippocampi of female rats compared to the male group, an indicator of reduced transcriptional activity. In addition, HDAC activity during the early morning was higher compared to afternoon groups in both male and female rats, while DNA methyltransferase 1 content was not altered by the time of day. Our findings demonstrate that hippocampal DNA methylation and histone acetylation status can be influenced by gender during the adolescent period, while the time of the day impacts HDAC activity.

关键词： adolescent rats DNA methyltransferase 1 histone deacetylase hippocampus time of the day gender epigenetic marks

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

红眼寄居蟹在实验室和野外条件下对贝壳的利用(英文)

引用

动物学报 2005年第5期51卷 813-820页

作者： Andrea de Lucca meireles Fernando Luis MANTELATTO Department of Biology FFCLRP University of S o Paulo Ph.D.Programin Comparative Biology Av . Bandeirantes 3900 Ribeir oPreto (SP) 14040-901 BrazilDepartment of Biology FFCLRP University of S o Paulo Ph.D.Programin Comparative Biology Av . Bandeirantes 3900 Ribeir oPreto (SP) 14040-901 Brazil

占据适宜的贝壳对于寄居蟹的发育、繁殖和存活至关重要。尽管很多研究探讨了蟹类对贝壳的选择,但寄居蟹选择多大的贝壳仍不清楚。在实验条件下,本文作者用巴西Anchieta岛上野生红眼寄居蟹( pagurusbrevidactylus)最常利用的黑衣蟹守螺( ... 详细信息

占据适宜的贝壳对于寄居蟹的发育、繁殖和存活至关重要。尽管很多研究探讨了蟹类对贝壳的选择,但寄居蟹选择多大的贝壳仍不清楚。在实验条件下,本文作者用巴西Anchieta岛上野生红眼寄居蟹( pagurusbrevidactylus)最常利用的黑衣蟹守螺( Cerithium atratum)和节桑椹螺( Morula nodulosa)进行了贝壳选择实验,通过回归分析确定目标贝类及其大小。观察到寄居蟹对一种独特贝类的选择具有性别意义,从而验证了野外观察结果。雄性明显地倾向选择黑衣蟹守螺的贝壳,而产卵和非产卵的雌性个体对腹足类贝壳的选择差异不显著。尽管两性之间对适宜贝壳的选择存在差异,贝壳适宜度指数(SAI)表明,种群占据那些足够大的贝壳(SAI =1·20±0·23)。红眼寄居蟹对贝壳利用的这种模式可能是为了避免与体型相似同域物种的竞争,从而在后来的生长中减少频繁地更换贝壳。根据目前的数据可以得到以下结论:红眼寄居蟹对贝壳的选择不仅取决于贝壳的参数,而且还与寄居蟹的个体和性选择有关[动物学报51 (5) : 813 -820 , 2005]。

关键词：异尾下目寄居蟹贝壳选择贝壳利用

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

paternal physical exercise modulates global DNA methylation status in the hippocampus of male rat offspring

引用

Neural Regeneration Research 2019年第3期14卷 491-500页

作者： Christiano Spindler Ethiane Segabinazi Andre Luis Ferreira de meireles Francele Valente piazza Filipe Mega Gabriela dos Santos Salvalaggio Matilde Achaval Viviane Rostirola Elsner Simone Marcuzzo programa de pos-Graduacao em Neurociencias Instituto de Ciencias Basicas da Saude Universidade Federal do Rio Grande do Sul Laboratorio de Histofisiologia Comparada Departamento de Ciencias Morfologicas Instituto de Ciencias Basicas da Saude Universidade Federal do Rio Grande do Sul programa de pos-Graduacao em Biociências e Reabilitacao Centro Universitario Metodista-IPA

It is widely known that maternal physical exercise is able to induce beneficial improvements in offspring cognition; however, the effects of paternal exercise have not been explored in detail. The present study was designed to evaluate the impact of paternal physical exercise on memory and learning, neuroplasticity and DNA methylation levels in the hippocampus of male offspring. Adult male Wistar rats were divided into two groups: sedentary or exercised fathers. The paternal preconception exercise protocol consisted of treadmill running, 20 minutes daily, 5 consecutive days per week for 22 days, while the mothers were not trained. After mating, paternal sperm was collected for global DNA methylation analysis. At postnatal day 53, the offspring were euthanized, and the hippocampus was dissected to measure cell survival by 5-bromo-2′-deoxiuridine and to determine the expression of synaptophysin, reelin, brain-derived neurotrophic factor and global DNA methylation levels. To measure spatial memory and learning changes in offspring, the Morris water maze paradigm was used. There was an improvement in spatial learning, as well as a significant decrease in hippocampal global DNA methylation levels in the offspring from exercised fathers compared with those from sedentary ones; however, no changes were observed in neuroplasticity biomarkers brain-derived neurotrophic factor, reelin and 5-bromo-2′-deoxiuridine. Finally, the global DNA methylation of paternal sperm was not significantly changed by physical exercise. These results suggest a link between paternal preconception physical activity and cognitive benefit, which may be associated with hippocampal epigenetic programming in male offspring. However, the biological mechanisms of this modulation remain unclear.

关键词： epigenetics preconception methylation learning treadmill running fetal programming inheritance sperm nerve regeneration

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

Three decades of hepatitis B control with vaccination

引用

World Journal of Hepatology 2015年第18期7卷 2127-2132页

作者： Liliane C meireles Rui Tato Marinho pierre Van Damme Department of Gastroen- terology and Hepatology Centro Hospitalar Lisboa Norte Centre for the Evaluation of Vaccination Vaccine and Infectious Disease Institute University of Antwerp

Hepatitis B virus(HBV) continues to represent a major health problem and can lead to acute liver failure, acute hepatitis, chronic carriership, chronic hepatitis of HBV, liver cirrhosis, liver cancer, liver transplantation and death. There is a marked difference in the geographic distribution of carriers. More than 240 million people worldwide are chronic HBV carriers. Mother-to-child transmission remains the most important mechanism of infection in countries with a high prevalence of HBV. percutaneous/parenteral transmission and unsafe sexual practices are important mode of spread transmission of HBV in other countries. Vaccination against HBV is the gold measure for primary prevention and control of the disease. Currently, 179 countries have added HBV vaccination to their routine vaccination programs with great results. Neonatal immunization with HBV vaccine has been one of the most highly effective measures in public health and the first anti-cancer program to be launched. In this paper we review the achievements for the last three decades.

关键词： Cirrhosis Vaccination primary prevention Hepatocel

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

Structural Analysis of Timber Gridshell Covered by OSB panels Considering the Effect of Wind

引用

Journal of Civil Engineering and Architecture 2022年第6期16卷 277-293页

作者： Flavio meireles Caffarello Nilson Tadeu Mascia Cilmar Donizeti Basaglia Julio Soriano Fuqua School of Business 100 Fuqua Drive DuhamNorth Caroline 27708USA School of Civil Engineering Architecture and Urban DesignState University of CampinasRua Saturnino de Brito224Campinas 13083-889Brazil School of Agricultural Engineering State University of CampinasAv.Cândido Rondon501Campinas 13083-875Brazil

Timber gridshells have been increasingly gaining attention for combining structural efficiency with an attractive architectural design.The use of timber in this structural system gives freedom to the architectural configuration and implies light and efficient construction.This study presents a methodology for the structural analysis of a gridshell covered by OSB(oriented strand board)panels,taken as a case study,and evaluates the model using finite element analysis.The gridshell’s final geometry was obtained from simulations of the effect of permanent load on the mesh.The structural evaluation was numerically estimated via ANSYS software’s CFX platform,considering the effect of wind on the fluid-structure interaction,as well as the results of a static analysis of the structure,including ultimate and serviceability limit state verifications.To assess the influence of the OSB panels on the gridshell’s behavior,two values of elastic modulus are considered.The analysis of a timber gridshell,which covers a span of 14 m by 28 m,demonstrated that this lightweight structure can be considered rigid,and the increase in stiffness of the OSB panels,used as the structure’s coating,can represent an expressive strength and stiffness gain for this type of gridshell.

关键词： CFD(computational fluid dynamics) finite element analysis external wind pressure coefficient stiffness limit state design

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

A Rare presentation of Erdheim-Chester Disease Overlaped with Langerhans Histiocytosis

引用

International Journal of Clinical Medicine 2023年第10期14卷 438-448页

作者： Ivo De Menezes Filadélfia Martins Rosineli Oliveira Victor meireles Felipe Nobre Carlos Alberto Studart Gomes Hospital Fortaleza Brazil

Erdheim-Chester Disease (ECD) is a rare condition and has various differential diagnoses with other forms of histiocytosis, classified as one of non-Langerhans histiocytosis. The diagnosis of this condition remains challenging because its presentation includes non-specific systemic manifestations that can affect different organs caused by deposition of lipids and fibrosis. Most common include bone pain followed by progressive weakness and different lung manifestations. This case is about a rare presentation of ECD with Langerhans Histiocytosis as overlap syndrome, with findings of both diseases in a middle aged woman that presented dyspnea as the first symptom. The patient was treated initially as heart failure and remained without any improvement, being admitted to investigate. After a stricted follow-up, bone and lung involvement were noticed and a skin biopsy unveiled xanthomatized macrophages accompanied by Touton giant cells. This condition remains an important clinical entity and should provide new insights for clinicians dealing with respiratory diseases.

关键词： Erdheim-Chester Langerhans Histicytosis pulmonary Histiocytosis

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

Checking procalcitonin suitability for prognosis and antimicrobial therapy monitoring in burn patients

引用

Burns & Trauma 2018年第1期6卷 39-48页

作者： Luís Cabral Vera Afreixo Rita meireles Miguel Vaz Catarina Chaves Marisa Caetano Luís Almeida JoséArtur paiva Department of plastic Surgery and Burns Unit Unidade de QueimadosCoimbra University Hospital Centre(CHUC)Av.Bissaya Barreto s/n3000-075 CoimbraPortugal Autonomous Section of Health Sciences(SACS) University of AveiroAveiroPortugal CIDMA-Center for Research and Development in Mathematics and Applications iBiMEDInstitute for BiomedicineUniversity of AveiroAveiroPortugal Clinical pathology Department Coimbra University Hospital Centre(CHUC)CoimbraPortugal pharmacy Department Coimbra University Hospital Centre(CHUC)CoimbraPortugal MedinUp Department of Pharmacology and TherapeuticsFaculty of MedicineUniversity of PortoPortoPortugal Department of Emergency and Intensive Care Medicine Centro Hospitalar Sao JoaoPortoPortugal Faculty of Medicine University of PortoGrupo de Infeccao e SépsisPortoPortugal.

Background: Due to greater infection susceptibility, sepsis is the main cause of death in burn patients. Quick diagnosis and patient stratification, early and appropriated antimicrobial therapy, and focus control are crucial for patients’survival. On the other hand, superfluous extension of therapy is associated with adverse events and arousal of microbial resistance. The use of biomarkers, necessarily coupled with close clinical examination, may predict outcomes, stratifying patients who need more intensive care, and monitor the efficacy of antimicrobial therapy, allowing faster de-escalation or stop, reducing the development of resistance and possibly the financial burden, without increasing mortality. The aim of this work is to check the suitability of procalcitonin (pCT) to fulfill these goals in a large sample of septic burn patients. Methods: One hundred and one patients, with 15% or more of total body surface area (TBSA) burned, admitted from January 2011 to December 2014 at Coimbra Burns Unit (CBU), in portugal were included in the sample. All patients had a diagnosis of sepsis, according to the American Burn Association (ABA) criteria. The sample was factored by survival (68 survivors and 33 non-survivors). The maximum value of pCT in each day was used for statistical analysis. Data were summarized by location measures (mean, median, minimum, maximum, quartiles) and dispersion measures (standard error and range measures). Statistical analysis was performed with SpSS?23.0 IBM? for Windows?. Results: There were statistically significant differences between pCT levels of patients from the survivor and non-survivor groups during the first and the last weeks of hospitalization as well as during the first week after sepsis suspicion, being slightly higher during this period. During the first 7 days of antimicrobial therapy, pCT was always higher in the non-survivor, still without reaching statistical significance, but when the analysis was extended till the 15th day, pCT increased significantly, rapidly, and s

关键词： Burns Sepsis procalcitonin prognosis Antimicrobial stewardship

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

Leptin immune programming: the assembly key between birth weight and future disease?

引用

Medical Theory and Hypothesis 2022年第4期5卷 11-19页

作者： Francisco Alves de Sousa Afonso Castro Ângela Reis Rego Ana Nóbrega pinto Miguel Bebiano Coutinho Luís meireles Otorhinolaryngology and Head&Neck surgery Centro Hospitalar Universitário do Porto4099-001 PortoPortugal

The developmental origins for health and disease concept supports that early life environment can affect future health balance and disease.Findings suggest that birthweight(BW)can be a useful indicator of processes that influence long-term health.In fact,there is increasing evidence associating BW with later-life infections,allergy,autoimmune and cancer diseases.To date,there is no common mechanism to explain BW’s direct influence on disease expression during the life cycle.On the other hand,leptin,a circulating hormone,has been pointed as relevant in many disease pathways,including immunological and oncological,and leptin levels seem to vary directly with BW.We suggest that BW could affect early immune programming through variant early-life leptin hormone levels.It is possible that higher leptin levels in higher BW and lower leptin levels in low BW relate to a shift in Th1 and Th2 responses,accounting for different incidences of infections,allergy,autoimmune and cancers,and raising an integrative hypothesis for the effect of BW on future disease.We hope that our hypothesis concerning the possible role of early life leptin levels on immune programming and future disease can be confirmed by experimental data.

关键词： immune programming birth weight leptin infections allergy cancer

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：