检索结果-南通市图书馆

Oxidative stress in Microcystis aeruginosa as a consequence of global climate change

BIOCELL 2016年第1期40卷 23-25页

作者： marcelo hernando CHRISTIAN HOUGHTON LEDA GIANNUZZI BERND KROCK DARIO ANDRINOLO GABRIELA MALANGA Departamento de Radiobiología Comisión Nacional de Energía AtómicaBuenos AiresArgentina Area de Toxicología Dpto.de Cs BiológicasFacultad de Ciencias Exactas.UNLP Alfred Wegener Institute BremerhavenGermany Instituto de Bioquímica y Medicina Molecular(IBIMOL)-Universidad de Buenos Aires(UBA) CONICETFisicoquímicaFacultad de Farmacia y BioquímicaJunín 956(C1113AAD)Buenos Aires.Argentina

Cyanobacteria are phototrophic organisms with great ecological and economical *** of the genus Microcystis are known for their potential ability to synthesize toxins,notably *** is a growing interest in the evaluation of oxidative stress in relation to the impact of global climate change on natural ecosystems in different trophic *** studies have focused on the analysis of organismal responses to mitigate the damage by controlling the generation of reactive oxygen *** in environ-mental factors caused by climate change generate a situation of oxidative damage in Microcystis aeruginosa as a direct or indirect *** this study we evaluate the effects of ultraviolet radiation and temperature on physiological and biochemical responses of a native ***(strain CAAT 2005-3).The results from the exposure to ultraviolet radiation doses and temperature changes suggest a high ability of *** to detect a potential stress situation as a consequence of reactive species production and to rapidly initiate antioxidant *** catalase activity is an antioxidant protection mechanism in *** for short and long term exposure to different changes in environmental ***,we found a ultraviolet-B radiation threshold dose above which oxidative stress exceeds the antioxidant protection and damage *** addition our results are in agreement with recent findings suggesting that microcystins may act as protein-modulating metabolites and protection against reactive oxygen *** is concluded that cyanobacteria have adaptative mechanisms that could lead to the replacement of species highly susceptible to oxidative stress by others with a higher system of antioxidant protection.

关键词： oxidative stress Cyanobacteria UVR temperature

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

Fatty acids in microalgae and cyanobacteria in a changing world:Contrasting temperate and cold environments

引用

BIOCELL 2022年第3期46卷 607-621页

作者： marcelo P.hernando IRENE R.SCHLOSS FLORENCIA DE LA ROSA MARLEEN DE TROCH Comisión Nacional de Energía Atómica(CNEA) Centro Atómico ConstituyentesDepartamento de RadiobiologíaSan MartínBuenos AiresArgentina Red de Investigación de Estresores Marinos-costeros en América Latina y el Caribe(REMARCO) Mar del Plata7602Argentina Instituto Antártico Argentino(IAA) San MartínBuenos AiresArgentina Centro Austral de Investigaciones Científicas(CADIC-CONICET) Ushuaia9410Argentina Universidad Nacional de Tierra del Fuego Ushuaia9410Argentina Instituto de Ciencias Básicas y Experimentales(ICBE) Universidad de MorónMorónBuenos AiresArgentina Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET) Buenos AiresArgentina Ghent University Faculty of SciencesBiology DepartmentMarine BiologyGhent9000Belgium

Under the present changing climate conditions and the observed temperature increase,it is of high importance to understand its effects on aquatic microbial life,and organisms’adaptations at the biochemical *** adjust to temperature or salinity stress and avoid cell damage,organisms alter their degree of fatty acids(FAs)***,temperature is expected to have strong effects on both the quantity and quality of FAs in aquatic *** we review some recent findings about FAs sensitivity to climate change in contrasting ***,heat waves may induce changes in the relative abundance of polyunsaturated FAs(PUFA).However,the impact of the exposure to warming waters is different in temperate and polar *** cold marine waters,high concentration of omega-3(ω3)FAs such as eicosapentaenoic acid(EPA)is promoted due to the activation of the desaturase *** this way,cells have enough energy to produce or activate antioxidant protection mechanisms and avoid oxidative stress due to heat ***,under high irradiance and heat wave conditions in temperate environments,photosystems’protection is achieved by decreasing EPA concentration due to desaturase *** FAs are transferred in aquatic food ***,any alteration in the production of essential FAs by phytoplankton(the main source ofω3)due to climate warming can be transferred to higher trophic levels,with cascading effects for the entire aquatic ecosystem.

关键词： Antarctic Temperate Essential FAs Increased temperature Microalgae Cyanobacteria

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

Mapping the metabolic responses to oxaliplatin-based chemotherapy with in vivo spatiotemporal metabolomics

引用

Journal of Pharmaceutical Analysis 2024年第2期14卷 196-210页

作者： Mariola Olkowicz Khaled Ramadan hernando Rosales-Solano Miao Yu Aizhou Wang marcelo Cypel Janusz Pawliszyn Department of Chemistry University of WaterlooWaterlooONCanada Jagiellonian Centre for Experimental Therapeutics(JCET) Jagiellonian UniversityKrakowPoland Latner Thoracic Surgery Research Laboratories Toronto General Hospital Research InstituteUniversity Health NetworkTorontoONCanada The Jackson Laboratory JAX Genomic MedicineFarmingtonCTUSA Division of Thoracic Surgery Department of SurgeryUniversity Health NetworkUniversity of TorontoToronto Lung Transplant ProgramTorontoONCanada

Adjuvant chemotherapy improves the survival outlook for patients undergoing operations for lung metastases caused by colorectal cancer (CRC). However, a multidisciplinary approach that evaluates several factors related to patient and tumor characteristics is necessary for managing chemotherapy treatment in metastatic CRC patients with lung disease, as such factors dictate the timing and drug regimen, which may affect treatment response and prognosis. In this study, we explore the potential of spatial metabolomics for evaluating metabolic phenotypes and therapy outcomes during the local delivery of the anticancer drug, oxaliplatin, to the lung. 12 male Yorkshire pigs underwent a 3 h left lung in vivo lung perfusion (IVLP) with various doses of oxaliplatin (7.5, 10, 20, 40, and 80 mg/L), which were administered to the perfusion circuit reservoir as a bolus. Biocompatible solid-phase microextraction (SPME) microprobes were combined with global metabolite profiling to obtain spatiotemporal information about the activity of the drug, determine toxic doses that exceed therapeutic efficacy, and conduct a mechanistic exploration of associated lung injury. Mild and subclinical lung injury was observed at 40 mg/L of oxaliplatin, and significant compromise of the hemodynamic lung function was found at 80 mg/L. This result was associated with massive alterations in metabolic patterns of lung tissue and perfusate, resulting in a total of 139 discriminant compounds. Uncontrolled inflammatory response, abnormalities in energy metabolism, and mitochondrial dysfunction next to accelerated kynurenine and aldosterone production were recognized as distinct features of dysregulated metabolipidome. Spatial pharmacometabolomics may be a promising tool for identifying pathological responses to chemotherapy.

关键词： Pulmonary metastases Colorectal cancer Adjuvant chemotherapy In vivo lung chemo-perfusion Solid-phase microextraction(SPME)microprobes Spatial metabolomics

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

Tree structure and diversity of lowland Atlantic forest fragments：comparison of disturbed and undisturbed remnants

引用

Journal of Forestry Research 2016年第3期27卷 605-609页

作者： Fabricio Alvim Carvalho Joao marcelo Alvarenga Braga marcelo Trindade Nascimento Departamento de Botanica Universidade Federal de Juiz de Fora. Campus Universitario s/n Sao PedroJuiz de Fora-MG 36036-900 Brazil Instituto de Pesquisas do Jardim Botanico do Rio de Janeiro. Rio de Janeiro-RJ Brazil Laboratorio de Ciencias Ambientais CBB Universidade Estadual do Norte Fluminense Campos dos Goytacazes-RJ 28013-602 Brazil

This study describes the tree community structure of three moist lowland Atlantic Forest fragments in Rio de Janeiro State, southeastern Brazil. Two fragments were disturbed and an undisturbed one was used as reference. Our hypothesis was that disturbed fragments show distinct structural patterns in comparison with undisturbed stands due to past disturbance practices and forest fragmentation. Four 100 ×5 m sampling plots were demarcated in each fragment and all live and dead trees with DBH C 5 cm were located, measured and identified. The results supported our hypothesis, due to the high values found for standing dead trees, an increase of dominance of a few pioneer species, lower values of large trees and species richness in disturbed fragments in comparison with the undisturbed one. The advanced fragmentation process in the Southern Brazilian lowland areas and the high species richness in undisturbed areas highlight these forest fragments as priority areas for conservation and management.

关键词： Phytosociology Tree community Forestfragmentation . Hotspot Brazil

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

Modeling neutral-atmospheric electromagnetic delays in a“big data”world

引用

Geo-Spatial Information Science 2018年第2期21卷 75-79页

作者： marcelo C.Santos Thalia Nikolaidou Department of Geodesy and Geomatics Engineering University of New BrunswickFrederictonCanada

If left unmodeled,the delay suffered by electromagnetic waves while crossing the neutral atmosphere negatively affects Global Navigation Satellite System *** modeling of the delay has been carried out by means of empirical models formulated based on climatological information or using information extracted from numerical weather prediction(NWP)*** paper explores the potential use of meteorological information of several types that will become available with the increasing number of sensors(e.g.a cell phone,or the thermometer of a nearby smart home)in *** can we make use of these potentially huge datasets,which may help to provide the best possible representation of the neutral atmosphere at any given time,as readily and as accurately as possible?This situation falls in the realm of Big Data.A few potential scenarios,a sequential improvement of Marini mapping function coefficients,a self-feeding NWP,and near real-time empirical model updates,are discussed in this *** pros and cons of each approach are discussed in comparison with what is done *** indicate that they have potential for a positive contribution.

关键词： Global navigation satellite system(GNSS) big data neutral atmosphere

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

Exact Computation of the Topology and Geometric Invariants of the Voronoi Diagram of Spheres in 3D

引用

Journal of Computer Science & Technology 2013年第2期28卷 255-266页

作者： Franois Anton Darka Mioc marcelo Santos Research Division of Geodesy National Space Institute Technical University of Denmark Department of Geodesy and Geomatics Engineering University of New Brunswick

In this paper, we are addressing the exact the Voronoi diagram of spheres using Wu＇s algorithm. computation of the Delaunay graph （or quasi-triangulation） and Our main contributions are first a methodology for automated derivation of invariants of the Delaunay empty circumsphere predicate for spheres and the Voronoi vertex of four spheres, then the application of this methodology to get all geometrical invariants that intervene in this problem and the exact computation of the Delaunay graph and the Voronoi diagram of spheres. To the best of our knowledge, there does not exist a comprehensive treatment of the exact computation with geometrical invariants of the Delaunay graph and the Voronoi diagram of spheres. Starting from the system of equations defining the zero-dimensional algebraic set of the problem, we are applying Wu＇s algorithm to transform the initial system into an equivalent Wu characteristic （triangular） set. In the corresponding system of algebraic equations, in each polynomial （except the first one）, the variable with higher order from the preceding polynomial has been eliminated （by pseudo-remainder computations） and the last polynomial we obtain is a polynomial of a single variable. By regrouping all the formal coefficients for each monomial in each polynomial, we get polynomials that are invariants for the given problem. We rewrite the original system by replacing the invariant polynomials by new formal coefficients. We repeat the process until all the algebraic relationships （syzygies） between the invariants have been found by applying Wu＇s algorithm on the invariants. Finally, we present an incremental algorithm for the construction of Voronoi diagrams and Delaunay graphs of spheres in 3D and its application to Geodesy.

关键词： Voronoi diagram of spheres Delaunay graph of spheres Wu's method invariant characteristic set

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

An investigation into the properties of ternary and binary cement pastes containing glass powder

引用

Frontiers of Structural and Civil Engineering 2019年第3期13卷 741-750页

作者： marcelo Frota BAZHUNI Mahsa KAMALI Ali GHAHREMANINEZHAD Department of Civil Architectural and Environmental EngineeringUniversity of MiamiCoral GablesFL 33146USA

The properties of binary and ternary cement pastes containing glass powder (GP) were *** at early age was evaluated using semi-adiabatic calorimetry and at late ages using non-evaporable water content and thermogravimetric *** transport characteristic was assessed by measuring electrical *** binary paste with slag showed the highest hydration activity compared to the binary pastes with GP and fly ash (FA).The results indicated that the pozzolanic behavior of the binary paste with GP was less than that of the binary pastes with slag or FA at late *** increase in the electrical resistivity and compressive strength of the binary paste with GP compared to other modified pastes at late ages was *** was shown that GP tends to increase the drying shrinkage of the *** pastes containing GP did not exhibit synergistic enhancements compared to the respective binary pastes.

关键词： cement paste glass powder pozzolanic reaction supplementary cementitious material

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

Flow regimes in wet conical spouted beds using glass bead mixtures

引用

Particuology 2008年第2期6卷 72-80页

作者： marcelo S.Bacelos Jos Teixeira Freire Universidade Federal de Sāo Carlos Centro de Ciências Exatas e de TecnologiaPrograma de Pós-Graduacāo em Engenharia QuímicaCentro de Secagem de PastasSuspensōes e SementesRod.Washington LuizKm 23513565-905CP 676Sāo CarlosSPBrazil

Using a high-viscosity Newtonian fluid, glycerol, an experimental investigation was carried out to evaluate the stable spouting regime in conical spouted beds using four particle mixtures： a reference （monoparticles）, a binary mixture, two ternary mixtures with flat and Gaussian distributions respectively. The mixtures were selected for particle diameters （dp） ranging from 1.09 to 4.98 mm and particle diameter ratios （dpL/dps） ranging from 1.98 to 4.0. Experimental data show that pressure fluctuation signals of the bed, as indicated by changes in their standard deviations, provide suitable information to identify the range of operational conditions for stable spouting. However, the analysis of skewness of curves of pressure fluctuation as a function of air velocity appears not sufficient to identify a particular flow regime. For glycerol in the spouting regime, the standard deviation is noted to increase with increasing glycerol concentration due to the growth of interparticle forces. The implications of these research findings on the drying of suspensions in conical spouted beds using glass bead mixtures are also discussed.

关键词： Conical spouted bed Binary and ternary mixtures Processing of pastes Spouting regimes Spouting stability Pressure fluctuation

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

Antarctic Paleontological Heritage:Late Cretaceous–Paleogene vertebrates from Seymour(Marambio)Island,Antarctic Peninsula

引用

Advances in Polar Science 2019年第3期30卷 328-355页

作者： marcelo A.REGUERO Instituto Antártico Argentino División Paleontología Vertebrados Museo de La Plata Facultad de Ciencias Naturales y Museo Universidad Nacional de La Plata Paseo del Bosque s/n Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)

Antarctica has significant environmental,scientific,historic,and intrinsic values,all of which are worth protecting into the *** continent has a discrete number of places of scientific interest that exhibit great potential as natural heritage sites;its geodiversity is of fundamental importance to scientific values of the continent,and the pursuit of geological and paleontological knowledge has had a strong influence on its historical *** Island was once called the‘Rosetta Stone’of Southern Hemisphere paleobiology,because this small island provides the most complete and richly fossiliferous Late Cretaceous–Paleogene sequence in *** particular,fossil vertebrates form part of the evidence used in reconstructing the history of life on *** heritage is considered a subset of geo-heritage that embodies both natural and historical components which has received only indirect *** Island is an outstanding paleontological area with high heritage value of its Late Cretaceous/Paleogene vertebrates and should be considered for geo-conservation and *** paper reviews vertebrate fossil occurrences and outcrops on Seymour Island and discusses some threats to these fossil sites.

关键词： fossil vertebrates geo-heritage geo-conservation Late Cretaceous-Paleogene Seymour Island Antarctica

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

Transient Ablation Regime in Circuit Breakers

引用

Plasma Science and Technology 2007年第6期9卷 653-656页

作者： Alexandre MARTIN Jean-Yves TREPANIER marcelo REGGIO Ecole Polytechnique MontrealQuebecCanada

Nozzle wall ablation caused by high temperature electric arcs is studied in the context of high voltage SF6 circuit breakers. The simplified ablation model used in litterature has been updated to take into account the unsteady state of ablation. Ablation rate and velocity are now calculated by a kinetic model using two layers of transition, between the bulk plasma and the ablating wall. The first layer （Knudsen layer）, right by the wall, is a kinetic layer of a few mean-free path of thickness. The second layer is collision dominated and makes the transition between the kinetic layer and the plasma bulk. With this new coupled algorithm, it is now possible to calculate the temperature distribution inside the wall, as well as more accurate ablation rates.

关键词： circuit breakers electric arc ablation Teflon radiation

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：