检索结果-南通市图书馆

Relationships between testate amoeba communities and water quality in Lake Donghu, a large alkaline lake in Wuhan, China

引用

Frontiers of Earth Science 2013年第2期7卷 182-190页

作者： Yangmin QIN Bertrand FOURNIER enrique lara Yansheng GU Hongmei WANG Yongde CUI Xiaoke ZHANG Edward A. D. MITCHELL State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences Wuhan 430074 China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China Laboratory of Soil Biology University of Neuchatel Rue Emile Argand 11 CH-2000 Neuchatel Switzerland Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China

The middle Yangtze Reach is one of the most developed regions of China. As a result, most lakes in this area have suffered from eutrophication and serious environmental pollution during recent decades. The aquatic biodiversity in the lakes of the area is thus currently under significant threat from continuous human activities. Testate amoebae （TA） are benthic （rarely planktonic） microorganisms characterized by an agglutinated or autogenous shell. Owing to their high abundance, preservation potential in lacustrine sediments, and distinct response to environmental stress, they are increasingly used as indicators for monitoring water quality and reconstructing palaeoenvironmental changes. However this approach has not yet been developed in China. This study presents an initial assessment of benthic TA assemblages in eight lakes of Lake Donghu in the region of Wuhan, China. Testate amoeba community structure was most strongly correlated to water pH. In more alkaline conditions, communities were dominated by Centropyxis aculeata, Difflugia oblonga, Pontigulasia compressa, Pon. elisa and Lesquereusia modesta. These results are consistent with previous studies and show that TA could be useful for reconstructing past water pH fluctuations in China. To achieve this, the next step will be to expand the database and build transfer function models.

关键词： testate amoebae (TA) water quality water pH Lake Donghu China

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

中国有壳变形虫Argynnia(Vucetich，1974)属的修订及若干环境重建问题探讨

引用

第四纪研究 2011年第6期31卷 1060-1066页

作者：秦养民张文静李鸿凯 Edward A. D. Mitchell enrique lara 张千帆朱荣顾延生中国地质大学生物地质与环境地质国家重点实验室武汉430074 厦门大学海洋与环境学院海洋生物多样性与全球变化实验室厦门361005 东北师范大学城市与环境学院长春130024 Laboratory of Soil Biology University of Neuchgtel Rue Emile Argand 11 CH-2000 Neuchgtel Switzerland

有壳变形虫是一类具外壳的陆相淡水根足纲(Rhizopoda)原生动物,广泛栖息于湖泊、泥炭、沼泽、土壤等各种淡水潮湿环境,由于其壳体具有很好的抗腐蚀性而在沉积物中保存下来,近年来广泛应用于泥炭和湖泊湿地的古环境重建研究中。大部分有... 详细信息

有壳变形虫是一类具外壳的陆相淡水根足纲(Rhizopoda)原生动物,广泛栖息于湖泊、泥炭、沼泽、土壤等各种淡水潮湿环境,由于其壳体具有很好的抗腐蚀性而在沉积物中保存下来,近年来广泛应用于泥炭和湖泊湿地的古环境重建研究中。大部分有壳变形虫是世界广泛分布的,但是也有一些种类具有一定的地带性分布格局。形态学和分子生物学的研究均已表明阿吉尼亚虫属(Argynnia Vucetich,1974)与梨壳虫属(Nebela Leidy,1874)有较大差别,而我国传统的有壳变形虫分类系统仍将它们统一划为梨壳虫属(Nebela)。本文在对神农架大九湖泥炭湿地有壳变形虫标本形态学观察的基础上,结合前人研究资料,将阿吉尼亚虫属(Argynnia)从梨壳虫属(Nebela)中分离出来,修正了我国传统的分类系统,并讨论了其生物地理学意义,目前在我国发现该属的2个种,即具尾阿吉尼亚虫Argynnia caudata(Leidy,1876)和齿口阿吉尼亚虫Argynnia dentistoma(Penard,1890)。本文还探讨了因有壳变形虫分类标准的差异可能引起的生态学转换函数和古环境重建问题。

关键词：有壳变形虫阿吉尼亚虫属梨壳虫属湿地环境重建

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

Using the endocannabinoid system as a neuroprotective strategy in perinatal hypoxic-ischemic brain injury

引用

Neural Regeneration Research 2013年第8期8卷 731-744页

作者： lara-Celador I. Goi-de-Cerio F. Antonia Alvarez enrique Hilario Department of Cell Biology and Histology School of Medicine and DentistryUniversity of the Basque Country GAIKER Technology Centre Bizkaia Science and Technology Park

One of the most important causes of brain injury in the neonatal period is a perinatal hypoxicischemic *** devastating condition can lead to long-term neurological deficits or even *** hypoxic-ischemic brain injury,a variety of specific cellular mechanisms are set in motion,triggering cell damage and finally producing cell *** therapeutic treatments against this phenomenon are still unavailable because of complex molecular mechanisms underlying hypoxic-ischemic brain *** a thorough understanding of the mechanism underlying neural plasticity following hypoxic-ischemic brain injury,various neuroprotective therapies have been developed for alleviating brain injury and improving long-term *** them,the endocannabinoid system emerges as a natural system of *** endocannabinoid system modulates a wide range of physiological processes in mammals and has demonstrated neuroprotective effects in different paradigms of acute brain injury,acting as a natural *** aim of this review is to study the use of different therapies to induce long-term therapeutic effects after hypoxic-ischemic brain injury,and analyze the important role of the endocannabinoid system as a new neuroprotective strategy against perinatal hypoxic-ischemic brain injury.

关键词： neural regeneration reviews perinatal hypoxia-ischemia brain injury brain plasticity,neuroprotective strategies cannabinoid system grants-supported paper photographs-containingpaper neuroregeneration

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

Dependence of dynamic contour and Goldmann applanation tonometries on peripheral corneal thickness

引用

International Journal of Ophthalmology(English edition) 2017年第10期10卷 1521-1527页

作者： Federico Saenz-Frances Claudia Sanz-Pozo lara Borrego-Sanz Luis Ja?ez Laura MoralesFernandez Jose Maria Martinez-de-la-Casa Julian Garcia-Sanchez Julian Garcia-Feijoo enrique Santos-Bueso Ophthalmology Department Clinico Universitario San Carlos HospitalComplutense University Institute of Knowledge Technology Complutense University

AIM：To determine the effects of peripheral corneal thickness（PCT）on dynamic contour tonometry（DCT）and Goldmann applanation tonometry（GAT）.METHODS：A cross-sectional *** created a software which calculates the corneal contour（CC）as a function of the radius from the corneal apex to each pixel of the *** software generates a central circumference with a radius of 1 mm and the remainder of the cornea is segmented in 5 rings concentric with corneal apex being its diameter not constant around the corneal circumference as a consequence of the irregular CC but keeping constant the diameter of each ring in each direction of the *** was determined as the mean thickness of the most eccentric *** weighted scatterplot smoothing（LOWESS）regression was used to determine the pattern of the relationship between PCT and both DCT and GAT ***,two multivariable linear regression models were *** each of them,the dependant variable was intraocular pressure（IOP）as determined using GAT and DCT *** both of the models the predictive variable was PCT though LOWESS regression pattern was used to model the relationship between the dependant variables and the predictor *** and sex were also introduced control variables along with their first-degree interactions with *** outcome measures include amount of IOP variation explained through regression models（R2）and regression coefficients（B）.RESULTS：Subjects included 109 eyes of 109 healthy *** regression suggested that a 2nd-degree polynomial would be suitable to model the relationshipbetween both DCT and GAT with *** PCT was introduced in both models as a linear and quadratic *** age nor sex nor interactions were statistically significant in both *** GAT model,R2was 17.14%（F=9.02;P=0.0002）,PCT linear term B was-1.163（95%CI：-1.163,-0.617）.PCT quadratic term B was 0.00081（95%CI：0.00043,0.00118）.For DCT model R2was 14.28%（F=9.29;P=0.0002

关键词： Goldmann applanation tonometry dynamic contour tonometry peripheral corneal thickness corneal thickness

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

Correlations between corneal and optic nerve head variables in healthy subjects and patients with primary open angle glaucoma

引用

International Journal of Ophthalmology(English edition) 2015年第6期8卷 1156-1161页

作者： Federico Saenz-Frances Luis Janez lara Borrego-Sanz Clara Berrozpe-Villabona Jose Maria Martinez-de-la-Casa Laura Morales-Fernandez Julian Garcia-Sanchez enrique Santos-Bueso Julian Garcia-Feijoo Department of Ophthalmology Clinico San Carlos HospitalComplutense University of Madrid Technology of Knowledge Institute Complutense University of Madrid

AIMTo correlate corneal variables (determined using the Pentacam) with optic nerve head (ONH) variables determined using the Heidelberg retina tomograph (HRT) in healthy subjects and patients diagnosed with primary open angle glaucoma (POAG).METHODSMeasurements were made in 75 healthy eyes and 73 eyes with POAG and correlations examined through Pearson correlation coefficients between the two sets of variables in the two subject groups. The corneal variables determined were corneal volume (CVol), central corneal thickness (CCT), overall corneal thickness (OvCT), the mean thickness of a circular zone centered at the corneal apex of 1 mm radius (zone I) and the mean thickness of several concentric rings, also centered at the apex until the limbus, each of 1 mm width (zones II to VI respectively). The ONH variables were determined using the *** following pairs of variables were correlated in the control group: CCT-disc area (DAr) (-0.48; P<0.0001), Zone I-DAr (-0.503; P<0.0001) and Zone II-DAr (-0.443; P<0.0001); and in the POAG group: CCT-cup-to-disc area ratio (CDRa) (-0.402; P<0.0001), Zone I-CDRa (-0.418; P<0.0001), Zone II-CDRa (-0.405; P=0.006), Zone I-cup shape measure (CSM) (-0.415; P=0.002), Zone II-CSM (-0.405; P=0.001), Zone IV-height variation contour (HVC) (0.378; P=0.002); Zone V-HVC (0.388, P<0.0001).CONCLUSIONSIn the healthy subjects, significant negative correlation was detected between central and paracentral corneal thickness and optic disc area. In contrast, the POAG patients showed significant negative correlation between central and paracentral corneal thickness and the cup-disc ratio and CSM, and positive correlation between peripheral corneal thickness and HVC.

关键词： glaucoma optic nerve head corneal thickness

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

Effect of Water Stress Induced by Polyethylene Glycol on Growth, Proline Accumulation in Agave americana L.

引用

Phyton-International Journal of Experimental Botany 2023年第2期92卷 629-643页

作者： Alfaro-Corres Arnoldo enrique Lecona-Guzman Carlos Alberto Gutiérrez-Miceli Federico Antonio Martínez-Esteves Manuel Silverio-Gómez María del Carmen Medina-lara María de Fátima Ruiz-Lau Nancy Laboratorio de Biotecnología vegetal Instituto Tecnológico de Tuxtla GutiérrezTuxtla Gutiérrez29050México Centro de Investigación Científica de Yucatán Unidad de Bioquímica y Biología Molecular de PlantasMérida97205México Insituto Nacional de Investigaciones Forestales Agrícolas y PecuariasHuimanguilloTabasco86400México CONACYT-Tecnológico Nacional de México/Instituto Tecnológico de Tuxtla Gutiérrez Tuxtla Gutiérrez29050México

The effect of water deficit was determined on both in vitro and soil seedling as well as in cells in suspension of Agave americana *** order to do the establishment of cells,the formation of callus was induced;for it two auxins were evaluated:2,4-dichlorophenoxyacetic acid(2,4-D)and 4-mino-3,5,6-trichloropicolinic acid(picloram)at three concentrations(0.25,0.5 and 0.75 mg L−1)in three explants(leaf,root and meristems)cultured in MS semisolid *** callogenesis response was related to the type and section of the explant,as well as the regulator used,and a cell suspension was established using 0.5 mg L−1 naphthaleneacetic acid(NAA)+0.5 mg L−1 Benzylaminopurine(BAP).Seedlings were exposed to polyethyleneglycol(15%and 30%w/v)with a water potential of−0.87 and−2.67 MPa,respectively,under soil *** stress was applied through restricted *** weight,root system growth,and chlorophyll concentration were some of the parameters that were affected by the effect of water deficit on *** *** concentration values were significantly decreased by 15 at 30%PEG(19.6 SPAD units)compared to the control *** in vitro plants,the highest concentration of proline was found in the roots,being the treatment with 30%polyethylene glycol where the highest concentration of this osmoregulator was obtained(62.5 mg g−1 DW).Under restricted irrigation conditions,an increase in proline concentration was observed both in the aerial part(2.2μg 100 g−1 DW)and in the root system(1.8μg 100 g−1 DW).However,the concentrations found were approximately ten times greater,less than those found under in vitro ***,the accumulation of proline can be considered an indicator of stress in Agave Americana *** in vitro.

关键词： Agave americana water deficit proline

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

Welding Effect at the Heat Affected Zone by Joining a Gray Cast Iron with Stainless Steel E308-16

引用

Materials Sciences and Applications 2023年第6期14卷 336-345页

作者： Yajaira Curiel-Razo enrique Curiel-Reyna Minerva Robles-Agudo Alberto lara-Guevara Ignacio Rojas-Rodríguez Facultad de Estudios Superiores-Cuautitlán Universidad Nacional Autónoma de México Cuautitlán-Izcalli México División Industrial Universidad Tecnológica de Querétaro Querétaro México División de Posgrado Facultad de Informática Universidad Autónoma de Querétaro Querétaro México

Different investigations of the union of dissimilar materials such as stainless steel and different castings have been carried out, but rapid cooling immediately after welding has not been considered, in this work it was investigated how rapid cooling affects the metallurgical microstructure and consequently the mechanical properties. The effect of welding parameters on the microstructure and mechanical properties of the joint between dissimilar metals, an E-308-16 austenitic stainless steel and Gray Cast Iron was also analyzed. Gray cast iron samples (GCI) were fabricated, welded and cooled. The main welding parameters studied in this work are the welding technique and the type of filler electrodes. Flux-coated electrode E-308-16 was applied for this different joint. An experimental study was carried out for the analysis of welded joints of similar and dissimilar steels. The microstructure of the welded joints was analyzed using an optical microscope, in the base metals, heat affected zone (HAZ) and filler metal. The mechanical properties of the welded joints were evaluated by Vickers microhardness and tensile strength tests. The hardness profile showed differences in hardness between the base metals, the heat affected zone and the filler metal. The metallurgical microstructures observed along the welded areas corresponded to the profile. The hardness differences determined the effect on the mechanical and metallurgical characteristics of the welded samples as a result of the cooling rate differences. This research work is important because it allows us to analyze the possibility of reworking pieces of dissimilar materials by welding or, failing that, to determine if this may or may not be possible.

关键词： Gray Iron Welding Hot Affected Zone Filler Metal Microstructure Dissimilar Metals

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

Characterization of Dissimilar Welding between 304 Stainless Steel and Gray Iron Using Nickel Coated Electrode

引用

Materials Sciences and Applications 2021年第12期12卷 614-621页

作者： Jesús García-Lira enrique Curiel-Reyna Yajaira Curiel-Razo Alberto lara-Guevara Ignacio Rojas-Rodríguez Facultad de Estudios Superiores-Cuautitlán Universidad Nacional Autónoma de México Cuautitlán-Izcalli Edo México División de Posgrado Facultad de Informática Universidad Autónoma de Querétaro Ave. de las Ciencias S/N Querétaro México División Industrial Universidad Tecnológica de Querétaro Querétaro México

This paper presents the study carried out to study the microstructure and mechanical properties of AISI 304 stainless steel and gray iron, in order to recognize the effect of welding parameters on the joint. The shielded metal arc welding technique was applied with a 3.2 mm diameter nickel coated electrode under preheating and post heat conditions at 350°C. Vickers hardness test and metallographic analysis were carried out at the heat affected zone and at the interface to determine the effect on mechanical and metallurgical characteristics. Vickers hardness differences among joint areas were directly related to microstructural changes. There are no significant differences in AISI 304 hardness, but the hardness increased at the heat affected zone and decreased at the filler metal. Grey iron hardness at the heat affected zone was even lower and more slightly superior than grey iron hardness.

关键词： Dissimilar Metal Welding Gray Cast Iron Heat Affected Zone Preheat and Post Heat Conditions Stainless Steel AISI 304

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

Anatomical characterization of central, apical and minimal corneal thickness

引用

International Journal of Ophthalmology(English edition) 2014年第4期7卷 668-672页

作者： Federico Saenz-Frances Martha Cecilia Bermúdez-Vallecilla lara Borrego-Sanz Luis Jaez J osé Marìa Martinez-de-la-Casa Laura Morales-Fernandez enrique Santos-Bueso Julián Garcia-Sanchez Julián Garcia-Feijoo Department of Ophthalmology Hospital Clínico San CarlosUniversidad Complutense de Madrid Instituto de Tecnologìa del Conocimiento Universidad Complutense de Madrid

·AIM: To anatomically locate the points of minimum corneal thickness and central corneal thickness(pupil center) in relation to the corneal apex.·METHODS: Observational, cross-sectional study, 299 healthy volunteers. Thickness at the corneal apex(AT),minimum corneal thickness(MT) and corneal thickness at the pupil center(PT) were determined using the pentacam. Distances from the corneal apex to MT(MD)and PT(PD) were calculated and their quadrant position(taking the corneal apex as the reference) determined:point of minimum thickness(MC) and point of central thickness(PC) depending on the quadrant position. Two multivariate linear regression models were constructed to examine the influence of age, gender, power of the flattest and steepest corneal axes, position of the flattest axis, corneal volume(determined using the Pentacam)and PT on MD and PD. The effects of these variables on MC and PC were also determined in two multinomial regression models.·RESULTS: MT was located at a mean distance of 0.909 mm from the apex(79.4% in the inferior-temporal quadrant). PT was located at a mean distance of 0.156 mm from the apex. The linear regression model for MD indicated it was significantly influenced by corneal volume(B =-0.024; 95% CI:-0.043 to-0.004). No significant relations were identified in the linear regression model for PD or the multinomial logisticregressions for MC and PC.·CONCLUSION: MT was typically located at the inferiortemporal quadrant of the cornea and its distance to the corneal apex tended to decrease with the increment of corneal volume.

关键词： cornealthickness anatomy glaucoma

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

Necklaces of PT-symmetric dimers

引用

Photonics Research 2018年第5期6卷 I0012-I0018页

作者： D.J.NODAL STEVENS BENJAMIN JARAMILLO AVILA B.M.RODRIGUEZ-lara Tecnologico de Monterrey Escuela de Ingenieria y CienciasAve.Eugenio Garza Sada 2501MonterreyN.L.64849Mexico CONACYT-Instituto Nacional de Astroffsica Optica y ElectronicaCalle Luis Enrique Erro No.1Sta.Ma.TonantzintlaPue.CP 72840Mexico Instituto Nacional de Astroffsica Optica y ElectronicaCalle Luis Enrique Erro No.1Sta.Ma.TonantzintlaPue.CP 72840Mexico

We study light propagation through cyclic arrays, composed by copies of a given PT-symmetric dimer, using a group theoretical approach and finite dement modeling. The theoretical mode-coupling analysis suggests the use of these devices as output port replicators where the dynamics is controlled by the impinging light field. This is confirmed in good agreement with finite element propagation in an experimentally feasible necklace of passive PT-symmetric dimers constructed from lossy and lossless waveguides.

关键词： Necklaces PT-symmetric dimers

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：