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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
411

Impact de la thromboectomie sur les embolies coronaires distales au cours des syndrômes coronaires aigus avec sus décalage du segment ST / Impact of thrombectomy on distales embolization during ST elevation myocardial infaction

Yameogo, Nobila Valentin 20 September 2017 (has links)
L’angioplastie coronaire primaire percutanée est le traitement de choix du syndrome coronarien aigu avec sus-décalage du segment ST (STEMI) avec une efficacité prouvée pour reperméabiliser l’artère coupable. Un flux TIMI (thrombolysis in myocardial infarction) 3 est généralement restauré dans plus de 90% des patients.Cependant, l'embolisation distale d'un thrombus angiographiquement visible (EDAV) a été identifiée comme l'une des complications majeures de l’angioplastie primaire dans le STEMI, car elle limite l'efficacité de la reperfusion myocardique et conduit à un plus mauvais pronostic.Notre objectif était de déterminer la fréquence des EDAV au cours de l’angioplastie primaire pour STEMI et d’en identifier les facteurs déterminants.Nous avons évalué 779 patients dont 560 hommes (71,9 %) victimes de STEMI et traités par angioplastie primaire. La thromboaspiration était réalisée dans plus de la moitié des cas (53%).L’âge moyen des patients était de 64,03 ± 14,67 ans. Les EDAV étaient fréquentes, de l’ordre de 15%.Les facteurs indépendants liés à la survenue d’EDAV étaient des facteurs cliniques à savoir l’âge > 60 ans, le sexe féminin, la thrombectomie, et la coronaire droite coupable. Aucun critère de la lésion coupable n’a été identifié comme prédicteur d’EDAV.Chez les patients thrombectomisés, les EDAV survenaient dans 17,41% des cas. Les facteurs prédictifs indépendants de ces embolies distales étaient l’atteinte de la coronaire droite et un diamètre de référence de l’artère coupable ˃ 3 mm.Dans la mesure où le succès de la thrombectomie restaure le flux coronaire, nous nous sommes intéressés à la relation entre le succès de cette technique et la survenue des EDAV. Ce travail a montré que la survenue des EDAV n’était liée ni au score syntax, ni au succès de la thrombectomie, mais à deux critères angiographiques à savoir l’atteinte de la coronaire droite et un diamètre de l’artère coupable supérieur à 3 mm.Ces données suggèrent que la coronaire droite est l’élément central de survenue des EDAV. Il s’agit d’une artère double coudée et habituellement de gros calibre. Il semble de ce fait nécessaire de mener des ’études spécifiques sur la coronaire droite. / Percutaneous primary coronary angioplasty is the cornerstone for acute coronary syndrome with ST segment elevation (STEMI) treatment with proven efficacy to restore flow in culprit coronary artery. A TIMI (thrombolysis in myocardial infarction) 3 flow is generally restored in more than 90 % of patients. However, distal embolization of an angiographically visible thrombus (EDAV) has been identified as one of the major complications of primary angioplasty in STEMI because it limits the effectiveness of myocardial reperfusion and leads to a worse prognosis.Our objective was to determine the frequency of EDAVs during primary angioplasty for STEMI and to identify the determining factors.We evaluated 779 patients, including 560 men (71.9%) suffering from STEMI and treated with primary angioplasty. Thromboaspiration was performed in more than half of the cases (53%). The mean age of the patients was 64.03 ± 14.67 years. EDAVs were frequent (15%). Independent factors related to the occurrence of EDAV were clinical factors such as age > 60 years, female sex, thrombectomy, and culprit right coronary. No criterion from culprit lesion was identified as predictors of EDAV.In thrombectomized patients, EDAVs occurred in 17.41 % of cases. Independent predictor factors of these distal embolisms were right coronary artery target and culprit artery diameter ˃ 3 mm.Since the success of thrombectomy restores coronary flow, we are interested in the relationship between the success of this technique and the occurrence of EDAV. This work showed that the occurrence of EDAV was not related to the syntactic score nor to the success of the thrombectomy but to two angiographic criteria, namely right coronary artery disease and culprit artery diameter greater than 3 mm.These data suggest that right coronary artery is the central component of EDAV occurrence. It is a double bent artery and usually of large caliber. It therefore seems necessary to carry out specific studies on the right coronary artery.
412

Chemotaxonomic and microcharacter comparisons of selected species of Ligularia and Senecio section Amplectentes

Barr, Robin Reed January 2011 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
413

Connecting Cellular Redox State and Community Behavior in Pseudomonas aeruginosa PA14

Okegbe, Chinweike January 2016 (has links)
Redox chemistry is the basis for biological energy generation and anabolism. Redox conditions also serve as critical cues that modulate the development of many organisms. Roles for redox chemistry in the control of gene expression have been well characterized in multicellular eukaryotes, where oxygen availability in particular is a major developmental cue. As a gaseous metabolic substrate, oxygen becomes limiting as cellular communities grow, and can act as an indicator of aggregate size or developmental stage. In many of these cases, there are dedicated sensory and signal transduction networks that link oxygen and other redox signals to changes in gene expression and morphogenesis. The opportunistic pathogen Pseudomonas aeruginosa, like many species of microbes, forms multicellular structures called biofilms. Cells in biofilms can assume physiological states that differ from cells grown in well-mixed, homogeneous liquid cultures. They often exhibit increased resistance to environmental stresses and antibiotics, rendering biofilm physiology an important focus in the study of microbial pathogens. Biofilm development and architecture are tuned by environmental conditions. In turn, growth and survival in the community, and the specific structure of that community, give rise to internal microenvironments that are experienced by cells within a biofilm. Mechanisms that tune biofilm developmental programs in response to redox conditions are not well understood. This is due to challenges presented by most popular laboratory models of biofilm formation, which are not amenable to perturbation, characterization at the microscale, or high-throughput screening or analysis. In this thesis, I describe a standardized colony morphology assay for the study of P. aeruginosa PA14 biofilm development and use this model to address fundamental questions about the relationships between electron acceptor availability, biofilm cell physiology, and the regulation of biofilm morphogenesis. In the colony morphology assay, PA14 grows as ~1cm-diameter biofilms on agar-solidified media under controlled conditions, and displays a developmental pattern that is predictably influenced by changes in redox conditions. Microscale heterogeneity in chemical ecology can be profiled using microelectrodes, and the effects of specific mutations on development can be rigorously tested through high-throughput screening and the application of metabolic assays directly to biofilm samples. Prior to the work described here, application of the colony morphology assay had revealed that endogenous redox-active antibiotics called phenazines influence PA14 biofilm development such that defects in phenazine production promote colony wrinkling and the formation of a distinct wrinkle pattern. As phenazines can act as alternate electron acceptors for cellular metabolism, this provided an early clue to the role of redox conditions in determining biofilm architecture. The introduction to this thesis (Chapter 1) provides an overview of observations in P. aeruginosa and other microbes, drawing parallels between the physiology of colony biofilm development across phylogeny and highlighting specific preliminary studies that hint at redox-sensing mechanisms and signaling pathways that drive community morphogenesis. The associated Appendix A examines the effects of CORM-2, a synthetic compound that releases the respiratory poison carbon monoxide, on P. aeruginosa biofilm development. The inhibitory effects of CORM-2 are ameliorated by reducing agents and increased availability of electron donors for P. aeruginosa metabolism. Chapter 2 describes the foundational characterization of the P. aeruginosa PA14 colony morphology assay model, which showed that colony wrinkling is invoked under high intracellular NADH levels and electron acceptor-limiting conditions, suggesting that it is an adaptive strategy to increase access to electron acceptor. The associated Appendices B and C describe (i) a mathematical modeling approach demonstrating that wrinkle geometry is indeed optimized for efficient access to electron acceptors, and (ii) a study investigating the effects of phenazine antibiotics on the multicellular development of a eukaryotic microbe. Chapter 3 details the identification and characterization of a candidate mediator of the multicellular response to electron acceptor availability in PA14 called RmcA. RmcA contains domains that have been implicated in redox-sensitive developmental control in eukaryotic systems and domains that modulate intracellular levels of cyclic di-GMP (c-di-GMP). C-di-GMP is an important secondary messenger that controls social behaviors, including the secretion of factors required for colony biofilm structure formation, in diverse bacteria. RmcA thus bridges the gap between sensing of redox signals and colony morphogenesis. Appendix D outlines my approaches to purification and attempts to crystallize this and one other protein contributing to PA14 redox-driven colony morphogenesis. Finally, Appendix E describes the role of another protein that modulates c-di-GMP in response to metabolite-dependent signaling and physiological effects during interactions between P. aeruginosa and the fungus C. albicans. Together, the findings presented in this thesis have expanded our knowledge about the role that redox chemistry plays in biofilm development.
414

Aspectos morfológicos de ovos do gênero Rhodnius stal, 1859 (Heteroptera, Reduviidae) e sua importância na identificação específica / Morphological aspects of genre Rhodnius stal, 1859 (Heteroptera, Reduviidae) eggs and their importance in identification

Barata, Jose Maria Soares 11 May 1979 (has links)
O presente trabalho consta do estudo da escultura exocorial de ovos de dez espécies do gênero Rhodnius (Heteroptera-Reduviidae) através de microscopia eletrônica de varredura e microscopia ótica, com vistas à classificação taxionômica. Concomitantemente são apresentados dados sobre os aspectos gerais das cascas e dos ovos, quanto à forma, mensuração e coloração, bem como as modificações que poderão ocorrer quanto à forma e coloração desses ovos durante o desenvolvimento embrionário pós-oviposição. Utilizando as características citadas são elaboradas chaves dicotômicas para a classificação destas espécies, baseadas na utilização de caracteres visíveis pela microscopia ótica e microscopia eletrônica de varredura. / Morphological studies about exochorial patterns of Rhodnius (Heteroptera - Reduviidae) genus were made. Ten species were studied by scanning and common microscopy, and data were described mainly for systematic purposes. General aspects of eggs and shells such as shape, color patterns, and size measurements are also presented. Data about changes of shape and coloration ocurred during egg maturation were recorded and associated to the embryonic development. The characters described were utilized to work out identification keys for these Triatominae eggs, both by optical and scanning electron microscopy.
415

Novel morphological and physiological scaling relationships in the southern red wood ant

Perl, Craig Darren January 2018 (has links)
No description available.
416

Population Genetics, Karyology, and Morphology of Certain Species of the Peromyscus Truei Group

Hart, Billy Joe 05 1900 (has links)
The systematic relationship of two species of the Peromyscus truei group (P. truei and P. difficilis) was analysed through the application of starch gel electrophoresis, numerical taxonomy, and chromosomal techiques. Of 20 loci examined, 11 were monomorphic in all populations, two exhibited variation in only two populations, and seven loci were polymorphic in two or more populations. The mean number of polymorphic loci per population was 0.186, the mean number of polymorphic loci per individual was 0.024, and the proportion of loci heterozygous per individual was 2.4%. Chromosomal forms of P. truei, P. t. gentilis (FN 54) and P. t. truei (FN 62), and P. difficilis, P. d. petricola (FN 56) and P. d. nasutus (FN 58), were consistent for their karyotypes throughout their geographic ranges. No chromosomal hybrids were detected. Numerical analysis of morphological characters and similarity values based on allelic frequencies utilizing Roger's coefficient (S) demonstrated a distinct seperation of karyotypic forms of P. truei (S = 0.902) and P. difficilis (S = 0.924) and were below the mean value of S for conspecifics (S = 0.950). All data indicates that each chromosomal form of the P. truei group examined represents four distinct species. The oldest available name for chromosomal forms of P. true with a fundamental number of 62 is Peromyscus truei Shufeldt (1885) and the oldest available name for chromosomal forms with a fundamental number of 54 is Peromyscus gratus Merriam (1898). The oldest available name for chromosomal forms of P. difficils with a fundamental number of 58 is PeromYSCus nasutus Allen (1891) and the oldest available name for chromosomal forms with a fundamental number of 56 is Peromyscus difficilis Allen (1891).
417

Desenvolvimento embrionário e larval de Brycon gouldingi (Teleostei, Characidae)

Faustino, Francine [UNESP] 25 February 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-25Bitstream added on 2014-06-13T18:48:58Z : No. of bitstreams: 1 faustino_f_me_jabo.pdf: 2111122 bytes, checksum: 04ec462df798e747d75a33b6720ccf5b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Brycon gouldingi é uma espécie endêmica da Bacia Tocantins-Araguaia e estudos acerca de sua biologia e desenvolvimento ontogenético não se encontram na literatura. Analises morfométrica e morfológica dos períodos embrionário e larval desta espécie contribuirão para o conhecimento de sua biologia e potencial para o cultivo. Para este trabalho, foram capturados exemplares adultos da espécie, provenientes do Rio das Mortes - MT, principal afluente do Rio Araguaia e adaptados em cultivo por cerca de sete meses. Dez coletas foram realizadas na Piscicultura Buriti, Nova Mutum — MT, nos meses de dezembro de 2007 e janeiro de 2008, apos a reprodução induzida dos exemplares, sendo feitas amostragens nos seguintes tempos: extrusão, fertilização (tempo zero), 10, 20 e 30 segundos, 1 min, 1 min e 30s, a cada minuto ate completar 10min, a cada 5min ate atingir 30min, aos 45min, de hora em hora ate completar 24 horas, a cada 2 horas ate completar 48 horas e a cada 3 horas ate a absorção total do vitelo. Ovócitos, ovos, embriões e larvas foram observados em estereomicroscópio, microscopia eletrônica de varredura e microscopia de luz. Foi realizada também a morfometria dos ovócitos liberados por cada fêmea e das larvas desde o momento da eclosão ate a absorção total do vitelo, registrando-se valores de comprimento total da larva, altura e comprimento do saco vitelínico. A temperatura media da água nas incubadoras foi de 26,4±1,12 °C. 0 diâmetro dos ovócitos foi de 1,13±0,06 mm e 54% deles possuíam entre 1,11 e 1,20 mm. 0 período embrionário teve uma duração media de 13,9±0,06 horas pós-fertilização (hpf) sendo dividido em sete fases (zigoto,'1. clivagem, mórula, blástula, gástrula, histogênese/organogênese... / Brycon gouldingi is an endemic species of Tocantins-Araguaia basin and studies about its biology and ontogenetic development are not available in the literature. Morphometric and morphological analyses of embryonic and larval stages of this species will increase the knowledge about its biology and aquaculture potential. To perform this work, adult specimens from Mortes River- MT, the main tributary of Araguaia River were collected and adapted to captivity for seven months. Ten collections were carried out at Buriti Fishculture, Nova Mutum — MT, between December 2007 and January 2008, after induced spawning, comprising samplings in the following periods: extrusion, fertilization (time zero), 10, 20 and 30 seconds, lmin, lmin e 30s, at each minute up to 10min, each 5min up to 30min, at 45min, each hour up to 24 hours, each 2 hours up to 48 hours and each 3 hours up to total yolk absorption. Oocytes, eggs, embryos and larvae were observed under stereomicroscope, scanning electron microscope and light microscope. Morphometry analyses were also performed in the oocytes released by each female and in the oocytes up to total yolk absorption taking into account total larval length, yolk sac height and length values. The mean water temperature in the incubators was 26.4±1.12 °C. The oocyte diameter was equal to 1.13±0.06 mm and 54% of them were between 1.11 and 1.20 mm. The mean duration of the embryonic period was 13.9±0.06 hours post-fertilization (hpf) being divided into seven stages (zygote, cleavage, blastula, gastrula, histogenesis/organogenesis and hatching). At hatching, the total larval length was equal to 3.40±0.07 mm and the yolk sac volume was 0.46±0.081.iL. During the larval development, the appearance of adhesive organs on the cephalic dorsal region plus heart... (Complete abstract click electronic access below)
418

Identification and characterisation of the barley row-type gene VRS3

Bull, Hazel Joanne January 2015 (has links)
Barley row-type describes the number of grains present at a node on the barley spike. Two forms exist amongst cultivated barley: two-rowed with only the central of three spikelets fertile producing a single grain at a node and six-rowed with all three spikelets fertile, producing three grain at a node. Twelve regions of the barley genome have been associated with the row-type character with specific genes identified at three loci, <i>VRS1</i>, <i>VRS4</i> and <i>INT-C</i>. Advancements in the understanding of the genetic control underpinning barley row-type enables the identification of potential mechanisms for improving yield and yield architecture within the cereals.  This study used genetic linkage mapping in segregating F2 populations to refine the genetic location of the row-type locus, <i>VRS3</i>, to 16 candidate genes on barley chromosome 1H. Sequencing candidate loci in 32 <i>vrs3</i> induced mutant alleles identified <i>VRS3</i> to be a highly conserved JmjC histone demethylase, with two natural alleles within European cultivated barley. <i>VRS3</i> was further characterised as a potential means of improving grain uniformity within cultivated six-rowed barley, through phenotypic assessment of grain size in varying allele combinations of <i>VRS3</i>, <i>VRS1</i> and <i>INT-C</i>. The addition of six-rowed alleles at these loci was found to improve balance between central and lateral grain parameters, resulting in a more uniform grain sample. Analysis of gene expression found <i>Vrs3</i> to be constitutively expressed across a diverse panel of barley tissues. Moreover, detailed study within the developing inflorescence suggests a role for <i>Vrs3</i> in the regulation of the row-type genes <i>VRS1</i> and <i>INT-C. </i>
419

Análise filogenética de Cryptobranchia (Mollusca: Nudibranchia) com base em anatomia comparada / Phylogenetic analysis of Cryptobranchia (Mollusca: Nudibranchia) based on comparative anatomy

Lima, Patricia Oristanio Vaz de 12 December 2016 (has links)
Cryptobranchia é considerado o clado com maior número de representantes entre os Nudibranchia, com aproximadamente 1500 espécies e são reconhecidos por apresentarem uma cavidade para retração da brânquia quando perturbados. É considerado um táxon monofilético e apresenta as seguintes sinapomorfias: presença de um lábio; brânquia dorsal retrátil; cavidade ao redor do ânus; redução dos músculos do tubo oral e odontóforo; e próstata diferenciada. De acordo com a última sugestão filogenética, baseada em dados morfológicos, Cryptobranchia está dividido em dois táxons, também monofiléticos: Porostomata e Labiostomata. Este trabalho apresenta um estudo morfológico detalhado de alguns representantes-chave de Cryptobranchia e outros Nudibranchia visando testar a monofilia deste clado, bem como elucidar o posicionamento filogenético dos gêneros de cada família do clado. Todas as famílias pertencentes à Cryptobranchia estão representadas, no entanto não todos os gêneros. Os gêneros estão representados, em sua maioria, pela espécie-tipo, totalizam um grupo interno de 30 espécies. O grupo externo inclui outros nudibrânquios e um Cephalaspidea (Haminoea elegans), utilizado para o enraizamento, totalizando 9 espécies. Uma análise cladística foi realizada, com buscas heurísticas e uma pesagem diferencial, específica determinada pela constante (K). Dentre várias conclusões, o resultado da análise confirmou a monofilia de Cryptobranchia, entretanto não confirmou a monofilia do táxon Labiostomata. Tambja brasiliensis (Polyceroidea) resultou como grupo-irmão de Cryptobranchia. Alguns sistemas foram analisados com mais precisão e mostraram-se potencialmente informativos, principalmente para táxons mais específicos / Cryptobranchia is considered have the largest number of representatives amongst Nudibranchia, with about 1500 known species, recognized in having a branchial sheath to retract the gills when disturbed. It is a monophyletic taxon with supported by following synapomorphies: labium present, dorsal gill retractable (when present), cavity around the anus, reduced number of oral tube bulb muscles, and differentiated prostate. According to the last phylogenetic suggestion, Cryptobranchia is divided in two monophyletic taxa: Porostomata and Labiostomata. This study presents a detailed morphological study of some key representatives of Cryptobranchia and other Nudibranchia taxa, aiming to test the monophyly and elucidate the phylogenetic position of the genera of each family. All families belonging to Cryptobranchia are represented, although not all genera. The genera are represented, in most cases, by the type species, totaling an internal group of 30 species. The outgroup is represented by other nudibranchs and a cepalaspidean (Haminoea elegans), for rooting, totalizing 9 species. A cladistic analysis is performed in a heuristic basis and a differential weighing, determined by specific constant (K). The result of the analysis confirmed the monophyly of Cryptobranchia, although the monophyly of the Labiostomata is not confirmed. Tambja brasiliensis (Polyceroidea) appears as Cryptobranchia sister group. Some systems were analyzed more accurately and show to be informative, especially for more specific taxa
420

A Comparison of Meristics and Morphometrics between Two Strains of Pond Cultured Striped Bass (Morone saxatilis)

Gornak, Steven 01 January 1991 (has links)
No description available.

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