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Methylglyoxal (MGO) elicits a heat-shock response in ARPE- 19 cells

Marques, Filipa Carvalhal
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Dissertação de Mestrado
Português
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O metilglioxal (MGO) é um metabolito dicarbonil altamente reactivo que se forma principalmente a partir da glicólise. Este composto constitui um dos principais precurso-res dos produtos finais avançados de glicação (AGEs – sigla inglesa), uma vez que rea-ge com proteínas, nucleótidos e lípidos, alterando a sua estrutura e função. O papel do MGO, assim como dos AGEs seus derivados, nas alterações deletérias sofridas por células e tecidos, tem sido extensivamente abordado nas últimas décadas. A acumulação de ambos os produtos contribui não só para o envelhecimento, mas também para uma série de doenças que incluem a diabetes mellitus (DM). No entanto, pouco se sabe acer-ca do efeito do MGO nas vias de controlo de qualidade proteica, bem como acerca da forma como as células respondem ao insulto tóxico resultante do MGO. Este estudo focou-se no efeito do MGO na resposta heat-shock. Esta via de respos-ta ao stress é mediada por chaperonas moleculares designadas heat-shock proteins (Hsps), que são capazes de reconhecer proteínas desnaturadas/modificadas e de promo-ver o seu enrolamento. Alternativamente, as Hsps podem enviar as proteínas irreversi-velmente modificadas para degradação no proteasoma, numa forma dependente da liga-se de ubiquitina CHIP. Com este trabalho...

Influence of organic shock loads in an ASBBR treating synthetic wastewater with different concentration levels

MOREIRA, Mariana Bueno; RATUSZNEI, Suzana Maria; RODRIGUES, Jose Alberto Domingues; ZAIAT, Marcelo; FORESTI, Eugenio
Fonte: ELSEVIER SCI LTD Publicador: ELSEVIER SCI LTD
Tipo: Artigo de Revista Científica
Português
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Safe application of the anaerobic sequencing biofilm batch reactor (ASBBR) still depends on deeper insight into its behavior when faced with common operational problems in wastewater treatments such as tolerance to abrupt variations in influent concentration, so called shock loads. To this end the current work shows the effect of organic shock loads on the performance of an ASBBR, with a useful volume of 5 L, containing 0.5-cm polyurethane cubes and operating at 30 degrees C with mechanical stirring of 500 rpm. In the assays 2 L of two types of synthetic wastewater were treated in 8-h cycles. Synthetic wastewater I was based on sucrose-amide-cellulose with concentration of 500 mg COD/L and synthetic wastewater II was based on volatile acids with concentration ranging from 500 to 2000 mg COD/L. Organic shock loads of 2-4 times the operation concentration were applied during one and two cycles. System efficiency was monitored before and after application of the perturbation. When operating with concentrations from 500 to 1000 mg COD/L and shock loads of 2-4 times the influent concentration during one or two cycles the system was able to regain stability after one cycle and the values of organic matter, total and intermediate volatile acids...

Time- and Fluid-Sensitive Resuscitation for Hemodynamic Support of Children in Septic Shock Barriers to the Implementation of the American College of Critical Care Medicine/Pediatric Advanced Life Support Guidelines in a Pediatric Intensive Care Unit in a Developing World

OLIVEIRA, Claudio F.; SA, Flavio R. Nogueira de; OLIVEIRA, Debora S. F.; GOTTSCHALD, Adriana F. C.; MOURA, Juliana D. G.; SHIBATA, Audrey R. O.; TROSTER, Eduardo J.; VAZ, Flavio A. C.; CARCILLO, Joseph A.
Fonte: LIPPINCOTT WILLIAMS & WILKINS Publicador: LIPPINCOTT WILLIAMS & WILKINS
Tipo: Artigo de Revista Científica
Português
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Objectives: To analyze mortality rates of children with severe sepsis and septic shock in relation to time-sensitive fluid resuscitation and treatments received and to define barriers to the implementation of the American College of Critical Care Medicine/Pediatric Advanced Life Support guidelines in a pediatric intensive care unit in a developing country. Methods: Retrospective chart review and prospective analysis of septic shock treatment in a pediatric intensive care unit of a tertiary care teaching hospital. Ninety patients with severe sepsis or septic shock admitted between July 2002 and June 2003 were included in this study. Results: Of the 90 patients, 83% had septic shock and 17% had severe sepsis; 80 patients had preexisting severe chronic diseases. Patients with septic shock who received less than a 20-mL/kg dose of resuscitation fluid in the first hour of treatment had a mortality rate of 73%, whereas patients who received more than a 40-mL/kg dose in the first hour of treatment had a mortality rate of 33% (P < 0.05.) Patients treated less than 30 minutes after diagnosis of severe sepsis and septic shock had a significantly lower mortality rate (40%) than patients treated more than 60 Minutes after diagnosis (P < 0.05). Controlling for the risk of mortality...

Myosin light chain kinase is necessary for post-shock mesenteric lymph drainage enhancement of vascular reactivity and calcium sensitivity in hemorrhagic-shocked rats

Zhang,Y.P.; Niu,C.Y.; Zhao,Z.G.; Zhang,L.M.; Si,Y.H.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2013 Português
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Vascular hyporeactivity is an important factor in irreversible shock, and post-shock mesenteric lymph (PSML) blockade improves vascular reactivity after hemorrhagic shock. This study explored the possible involvement of myosin light chain kinase (MLCK) in PSML-mediated vascular hyporeactivity and calcium desensitization. Rats were divided into sham (n=12), shock (n=18), and shock+drainage (n=18) groups. A hemorrhagic shock model (40±2 mmHg, 3 h) was established in the shock and shock+drainage groups. PSML drainage was performed from 1 to 3 h from start of hypotension in shock+drainage rats. Levels of phospho-MLCK (p-MLCK) were determined in superior mesenteric artery (SMA) tissue, and the vascular reactivity to norepinephrine (NE) and sensitivity to Ca2+ were observed in SMA rings in an isolated organ perfusion system. p-MLCK was significantly decreased in the shock group compared with the sham group, but increased in the shock+drainage group compared with the shock group. Substance P (1 nM), an agonist of MLCK, significantly elevated the decreased contractile response of SMA rings to both NE and Ca2+ at various concentrations. Maximum contractility (Emax) in the shock group increased with NE (from 0.179±0.038 to 0.440±0.177 g/mg...

Hydrogen sulfide in posthemorrhagic shock mesenteric lymph drainage alleviates kidney injury in rats

Han,B.; Zhao,Z.G.; Zhang,L.M.; Li,S.G.; Niu,C.Y.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 Português
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36.53%
Posthemorrhagic shock mesenteric lymph (PHSML) is a key factor in multiple organ injury following hemorrhagic shock. We investigated the role of hydrogen sulfide (H2S) in PHSML drainage in alleviating acute kidney injury (AKI) by administering D,L-propargylglycine (PPG) and sodium hydrosulfide hydrate (NaHS) to 12 specific pathogen-free male Wistar rats with PHSML drainage. A hemorrhagic shock model was established in 4 experimental groups: shock, shock+drainage, shock+drainage+PPG (45 mg/kg, 0.5 h prehemorrhage), and shock+drainage+NaHS (28 µmol/kg, 0.5 h prehemorrhage). Fluid resuscitation was performed after 1 h of hypotension, and PHMSL was drained in the last three groups for 3 h after resuscitation. Renal function and histomorphology were assessed along with levels of H2S, cystathionine-γ-lyase (CSE), Toll-like receptor 4 (TLR4), interleukin (IL)-10, IL-12, and tumor necrosis factor (TNF)-α in renal tissue. Hemorrhagic shock induced AKI with increased urea and creatinine levels in plasma and higher H2S, CSE, TLR4, IL-10, IL-12, and TNF-α levels in renal tissue. PHSML drainage significantly reduced urea, creatinine, H2S, CSE, and TNF-α but not TLR4, IL-10, or IL-12. PPG decreased creatinine, H2S, IL-10...

Role of protein kinase G on the post-shock mesenteric lymph blockage ameliorating vascular calcium sensitivity

Zhao,Zi-gang; Wei,Yan-ling; Niu,Chun-yu; Zhang,Yu-ping; Zhang,Li-min; Jiang,Li-na
Fonte: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia Publicador: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2013 Português
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36.57%
PURPOSE: To investigate the role of protein kinase G (PKG) in blocking post-shock mesenteric lymph (PSML) return ameliorating the calcium sensitivity in hemorrhagic shock rats. METHODS: Male Wistar rats were randomly divided into sham, shock, shock+ligation (shock plus mesenteric lymph duct ligation (MLDL)), shock+drainage (shock plus PSML drainage) groups. After shock (hypotension 40mmHg) for three hours or corresponding times, the superior mesenteric artery (SMA) was taken out for detecting the PKG and phospho PKG (p-PKG) contents, and the vascular rings of SMA were prepared for assaying the calcium sensitivity using an isolated organ perfusion system. RESULTS: The PKG and p-PKG contents of SMA in shock group were significantly increased than that of sham group, and MLDL or PSML drainage reducing the levels of PKG and p-PKG. Meanwhile, the vascular calcium sensitivity in shock group was significantly lower than that of sham group, MLDL or PSML drainage enhanced the calcium sensitivity. After incubating with PKG regulators in shock+ligation and shock+drainage groups, the PKG agonist 8Br-cGMP reduced the contractility of vascular rings to gradient calcium ions and Emax and the PKG inhibitor agonist KT5823 elevated the calcium sensitivity significantly. CONCLUSION: Protein kinase G plays an important role in post-shock mesenteric lymph blockage improving vascular calcium sensitivity.

Experimentally induced heat- and cold-shock tolerance in adult Panstrongylus megistus (Burmeister) (Hemiptera, Reduviidae)

Garcia,S. L.; Garcia,N. L.; Oliveira,L. R.; Rodrigues,V. L. C. C.; Mello,M. L. S.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2003 Português
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The survival rate of domestic male and female adult Panstrongylus megistus was studied after sequential heat and cold shocks in order to investigate shock tolerance compared to that previously reported for nymphs. Sequential shocks were such that a milder shock (0°C, 5°C, 35°C, or 40°C for 1 h) preceded a severe one (0°C or 40°C for 12 h), separated by intervals of 8, 18, 24, and 72 h at 28°C (control temperature). The preliminary thermal shock induced tolerance to the more severe one, although tolerance intensity depended on the initial shock temperature and the interval between treatments. Despite the observed tolerance, the survival rate for insects subjected to both shocks decreased when compared to that of individuals subjected to a single mild shock. When tolerance differed with sex, females showed greater values than males. In contrast to the response detected in nymphs, for which higher heat tolerance values were sustained for intervals of up to 24 h (preliminary shock, 35ºC) or even longer (preliminary shock, 40ºC) between sequential shocks, significant values were verified in adults only for shock intervals of up to 8 h (preliminary shock, 40ºC). While findings for nymphs exhibited considerable cold-shock tolerance under conditions in which preliminary shocks were given at 5ºC or 0ºC and the periods between shocks were up to 72 h long...

Shock factor investigation in a 3-D finite element model under shock loading

Zare,Amin; Janghorban,Maziar
Fonte: Associação Brasileira de Ciências Mecânicas Publicador: Associação Brasileira de Ciências Mecânicas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2013 Português
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In this paper, a scaled 3D ship under shock loading is modeled and analyzed by finite element method. By using of shock factor, there is no need to have different tests or even numerical simulation. Shock factor is an important parameter which clarifies shock severity. It was found that although the new shock factor introduced by Yao et al. (2009), when constant, predict the response better than older shock factor, but for varying values of shock factors, the older would predict better. It is also found that costly and time-consuming experiments can be avoided by proper finite element modeling, yet the errors can remain within an acceptable range. The results of the present work can be used as benchmarks for future works.

The Numerical Simulation of Radiative Shocks. I: The elimination of numerical shock instabilities using a localized oscillation filter

Sutherland, Ralph S; Bisset, David K; Bicknell, Geoffrey V
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Artigo de Revista Científica Formato: 270475 bytes; application/pdf
Português
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We address a numerical instability that arises in the directionally split computation of hydrodynamic flows when shock fronts are parallel to a grid plane. Transverse oscillations in pressure, density and temperature are produced that are exacerbated by thermal instability when cooling is present, forming post–shock ‘stripes’. These are orthogonal to the classic post–shock ’ringing’ fluctuations. The resulting post–shock ‘striping’ substantially modifies the flow. We discuss three different methods to resolve this problem. These include (1) a method based on artificial viscosity; (2) grid–jittering and (3) a new localized oscillation filter that acts on specific grid cells in the shock front. These methods are tested using a radiative wall shock problem with an embedded shear layer. The artificial viscosity method is unsatisfactory since, while it does reduce post–shock ringing, it does not eliminate the stripes and the excessive shock broadening renders the calculation of cooling inaccurate, resulting in an incorrect shock location. Grid–jittering effectively counteracts striping. However, elsewhere on the grid, the shear layer is unphysically diffused and this is highlighted in an extreme case. The oscillation filter method removes stripes and permits other high velocity gradient regions of the flow to evolve in a physically acceptable manner. It also has the advantage of only acting on a small fraction of the cells in a two or three dimensional simulation and does not significantly impair performance.

Numerical simulation of structural response and damage to simultaneous ground shock and airblast loads

Wu, C.; Hong, H.
Fonte: Pergamon-Elsevier Science Ltd Publicador: Pergamon-Elsevier Science Ltd
Tipo: Artigo de Revista Científica
Publicado em //2007 Português
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Current practice in analysis and design of structures to withhold surface explosions considers only airblast forces on structures. A surface explosion, in fact, generates both ground shock and airblast pressure on a nearby structure. In this paper, the influences of simultaneous ground shock and airblast forces on structural responses are investigated. Blast-induced surface ground motions and airblast pressures estimated in a previous study are employed as input in the analysis. A previously developed three-dimensional homogenized material model for a masonry wall including the equivalent elastic properties, strength envelope and damage threshold is used to model masonry wall. Another material damage model developed for reinforced concrete structures is used for modelling RC behavior due to explosive loads. These material models are programmed and linked to an available computer program LS-DYNA3D through its user subroutine capability. A one-story masonry infilled RC frame is used as an example in the study. Dynamic response and damage of the example structure to simultaneous ground shock and airblast forces, or separately to ground shock only or airblast forces only are calculated. It is found that in general, airblast load governs structural response and damage when the scaled distance is small. However...

Vascular reactivity in sepsis and platelet dysfunction in septic shock.

Reddi, Benjamin John
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2014 Português
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Sepsis remains an important global cause of morbidity and mortality. Sepsis can be complicated by pathological vasodilation causing cardiovascular septic shock. The present study identifies that dysfunction of the RhoA/Rho-kinase (ROK) signalling pathway in vascular smooth muscle cells contributes to vasomotor dysfunction in sepsis. ROK inhibits myosin light chain phosphatase (MLCP) through Thr855 phosphorylation of MYPT, the L30 kDa myosin binding regulatory subunit of MLCP. MLCP dephosphorylates myosin light chain (LC₂₀) inhibiting the acto-myosin cross-bridge cycling underpinning vasoconstriction or platelet contraction. ROK dependent MLCP inhibition therefore favours vasoconstriction and can be indexed by Thr855-MYPT phosphorylation. Western blot analysis identified that Thr855 phosphorylation of MYPT was reduced in arterial segments isolated from a murine caecal ligation and puncture model of sepsis. Wire myography yielded data consistent with reduced contractile responses to thromboxane A₂ receptor stimulation, high [K⁺] mediated depolarisation and direct PKC stimulation. α₁₋ adrenergic receptor mediated vasoconstriction was similar in septic and non-septic animals, possibly reflecting the multiple mechanisms by which α₁₋ adrenergic agonists elicit vasoconstriction. Certain bacterial toxins and inflammatory mediators have the potential to attenuate ROK signaling; our data suggest therapeutic benefit of agents that promote MLCP inhibition or which vasoconstrict independent of the RhoA/ROK pathway. Current vasopressor strategies for septic shock primarily rely upon catecholamine therapy. However...

Untersuchungen zur Rolle molekularer Chaperone und Hitzeschockprotein-assoziierter Peptide in der T-Zell-vermittelten Immunantwort - Peptidmotiv und Liganden des Miniaturschwein-MHC I Moleküls PD1; Studies investigating the role of molecular chaperones and heat-shock protein-associated peptides in the T-cell mediated immune response - Peptide motif and ligands of the miniature swine MHC-class I molecule PD1

Scherer, Hans Ulrich
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
Português
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36.53%
Hitzeschockproteine (HSP wie Gp96, Hsp70 u.a.) sind potente Stimulatoren des Immunsystems. Aufgrund phylogenetisch alter, hochkonservierter Strukturen ihres molekularen Aufbaus geht ihre Fähigkeit zur Immunstimulation über Speziesgrenzen hinaus, so daß für das menschliche Immunsystem sowohl mikrobielle als auch humane Hitzeschockproteine eine wichtige Rolle spielen. Neben einer unspezifischen, antigen-unabhängigen Aktivierung antigenpräsentierender Zellen über Rezeptoren der Toll-Familie (im wesentlichen TLR2 und TLR4) besitzen einige von ihnen die Fähigkeit, antigenspezifische Immunreaktionen auszulösen. Aus Tumorzellen isoliertes Gp96 z.B. löst, in Mäuse injiziert, die den gleichen spezifischen Tumortyp tragen, aus dem Gp96 zunächst isoliert wurde, eine für diesen Tumor spezifische Immunantwort aus. Durch zytotoxische T-Lymphozyten (CTLs) vermittelt und für zahlreiche Tumorarten nachgewiesen bildet diese Erkenntnis die Grundlage für neue therapeutische Strategien gegen menschliche Tumoren mit HSPs als Vakzine. Für die spezifische immunogene Wirkung der ansonsten zellunspezifischen HSPs werden endogene, nicht-kovalent an die HSPs gebundene Peptide verantwortlich gemacht, die über eine rezeptorvermittelte Endozytose des HSPs in den MHC I - Antigenprozessierungsweg antigenpräsentierender Zellen gelangen (sog. cross-presentation). Sie stellen ein Abbild des Peptidrepertoires der Tumorzelle dar...

Funktionelle Charakterisierung von Hitzeschockfaktoren aus Arabidopsis thaliana (L.) Heynh; Functional characterisation of heat shock factors from Arabidopsis thaliana (L.) Heynh

Lohmann, Klaus Christian
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
Português
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36.55%
Die Hitzeschockfaktoren (HSF) eukaryotischer Organismen sind konservierte Transkriptionsfaktoren mit starken Homologien innerhalb der DNA-Bindungsdomäne. Unter physiologischen Stressbedingungen binden HSF in oligomerer Form an Hitzeschockelemente (HSE) innerhalb der Promotoren von HS-Genen und induzieren deren transiente Transkription. Erhöhte Titer an HS-Genprodukten schützen vor akuten Zellschäden und führen zum Erwerb höherer Stresstoleranz. Neben dieser Rolle als zentrale Regulatoren der HS-Reaktion wurden für einzelne Vertreter der HSF-Familie zellstadium- und entwicklungsspezifische Funktionen nachgewiesen. Auf die Expression ihrer Zielgene, bei denen es sich nicht ausschließlich um klassische HS-Gene wie Hitzeschockproteine handelt, üben HSF in einigen Fällen auch negativ-regulatorische Eigenschaften aus. Das Genom von Arabidopsis thaliana enthält die für Pflanzen typische, große Anzahl von 21 HSF-Homologen. Sechs von ihnen waren Gegenstand dieser Arbeit. Aufgrund struktureller Besonderheiten innerhalb ihrer Aminosäuresequenz gehören jeweils drei der Klasse-A und drei der Klasse-B an. Im Einzelnen handelte es sich um HSF1 (AtHsfA1a), HSF2 (AtHsfA1e), HSF3 (AtHsfA1b) und HSF4 (AtHsfB1), HSF6 (AtHsfB2a), HSF7 (AtHsfB2b); wobei die Angaben in Klammern der von Nover et al. (2001) vorgeschlagenen Nomenklatur entsprechen. Die funktionelle Charakterisierung dieser HSF umfasste deren Expressionsanalyse...

Shock & Vibration Computational Laboratory, Ship shock trial simulations

Shin, Young S.; Didoszak, Jarema M.; Christian, Tom
Fonte: Escola de Pós-Graduação Naval Publicador: Escola de Pós-Graduação Naval
Tipo: Brochure
Português
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46.36%
Our goal at the Naval Postgraduate School Shock and Vibration Computational Laboratory (SVCL) has been to develop and validate modeling and simulation capabilities to improve the survivability of ships subjected to realistic underwater explosions.

Post-hemorrhagic shock mesenteric lymph is an important contributor to cardiac dysfunction following hemorrhagic shock

Du,Hui-bo; Wang,Si-hai; Zhao,Zi-gang; Niu,Chun-yu
Fonte: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia Publicador: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2015 Português
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PURPOSE:To evaluate whether post-hemorrhagic shock mesenteric lymph (PSML) is involved in cardiac dysfunction induced by hemorrhagic shock.METHODS: The hemorrhagic shock model (40±2 mmHg, 3h) was established in rats of the shock and shock+drainage groups; and PSML drainage was performed from hypotension 1-3h in the shock+drainage rats. Then, the isolated hearts were obtained from the rats for the examination of cardiac function with Langendorff system. Subsequently, the isolated hearts were obtained from normal rats and perfused with PSML or Krebs-Henseleit solution, and the changes of cardiac function were observed.RESULTS:The left ventricular systolic pressure (LVSP) and the maximal rates of LV developed pressure (LVDP) rise and fall (±dP/dtmax) in the shock and shock+drainage groups were lower than that of the sham group; otherwise, these indices in the shock+drainage group were higher compared to the shock group. In addition, after isolated hearts obtained from normal rats perfusing with PSML, these cardiac function indices were gradual decline along with the extension of time, such as heart rate, LVSP, ±dP/dtmax, etc.CONCLUSION:Post-hemorrhagic shock mesenteric lymph is an important contributor to cardiac dysfunction following hemorrhagic shock.

Hydrogen sulfide in posthemorrhagic shock mesenteric lymph drainage alleviates kidney injury in rats

Han,B.; Zhao,Z.G.; Zhang,L.M.; Li,S.G.; Niu,C.Y.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2015 Português
Relevância na Pesquisa
36.53%
Posthemorrhagic shock mesenteric lymph (PHSML) is a key factor in multiple organ injury following hemorrhagic shock. We investigated the role of hydrogen sulfide (H2S) in PHSML drainage in alleviating acute kidney injury (AKI) by administering D,L-propargylglycine (PPG) and sodium hydrosulfide hydrate (NaHS) to 12 specific pathogen-free male Wistar rats with PHSML drainage. A hemorrhagic shock model was established in 4 experimental groups: shock, shock+drainage, shock+drainage+PPG (45 mg/kg, 0.5 h prehemorrhage), and shock+drainage+NaHS (28 µmol/kg, 0.5 h prehemorrhage). Fluid resuscitation was performed after 1 h of hypotension, and PHMSL was drained in the last three groups for 3 h after resuscitation. Renal function and histomorphology were assessed along with levels of H2S, cystathionine-γ-lyase (CSE), Toll-like receptor 4 (TLR4), interleukin (IL)-10, IL-12, and tumor necrosis factor (TNF)-α in renal tissue. Hemorrhagic shock induced AKI with increased urea and creatinine levels in plasma and higher H2S, CSE, TLR4, IL-10, IL-12, and TNF-α levels in renal tissue. PHSML drainage significantly reduced urea, creatinine, H2S, CSE, and TNF-α but not TLR4, IL-10, or IL-12. PPG decreased creatinine, H2S, IL-10, and TNF-α levels...

Estudo do comportamento ao dano por choque térmico de um concreto refratário, contendo agregados de andaluzita, sinterizado em diferentes temperaturas; Study of the of thermal shock behavior of a castable containing andalusite aggregates sintered at different temperatures.

Garcia, Giseli Cristina Ribeiro
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 27/08/2010 Português
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36.54%
O conhecimento da resistência ao dano por choque térmico de materiais refratários é uma das características mais importantes para determinar seu desempenho em muitas aplicações, pois quando os refratários são submetidos a abruptas e severas variações de temperatura, estes podem sofrer danos. A resistência ao dano por choque térmico de um material pode variar com o tamanho de grão, com o tipo e valor da tensão, com a taxa de carregamento e com outras condições de aplicação da tensão, ou seja, não é uma propriedade intrínseca do material. Os métodos correntemente utilizados para prever o comportamento da resistência ao dano por choque térmico são baseados nos trabalhos de Hasselman, responsável pelo estudo da determinação dos parâmetros de resistência ao choque térmico, R (oC), o parâmetro de resistência ao dano por choque térmico R\'\'\'\' (m), e o parâmetro de estabilidade da trinca sob tensão térmica Rst (m1/2.oC). As equações previstas por ele levam em consideração o módulo de Young, o módulo de ruptura, a energia de fratura e o coeficiente de expansão térmica do material a ser analisado. A resistência ao dano por choque térmico pode ser avaliada por meio de ciclos térmicos, isto é...

Distinct heat-shock element arrangements that mediate the heat shock, but not the late-embryogenesis induction of small heat-shock proteins, correlate with promoter activation in root-knot nematode feeding cells.

Barcala, Marta; García, Alejandra; Cubas, Pilar; Almoguera, Concepción; Jordano, Juan; Fenoll, Carmen; Escobar, Carolina
Fonte: Springer Publicador: Springer
Tipo: Artículo Formato: 722629 bytes; application/pdf
Português
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Genes coding small heat-shock proteins (sHSPs) show distinct behaviours with respect to environmental and developmental signals. Their transcriptional regulation depends on particular combinations of heat stress cis-elements (heat-shock elements; HSEs) but many aspects regarding their regulation remain unclear. Cyst and root-knot nematodes induce, in the roots of infected plants, the differentiation of special feeding cells with high metabolic activity (syncytia and giant cells, respectively), a process accompanied by extensive gene expression changes. The Hahsp17.7G4 (G4) promoter was active in giant cells and its HSE arrangements were crucial for this activation. In the present work, we provide further basis to associate giant cell expression with the heat-shock response of this gene class, by analysing additional promoters. The Hahsp17.6G1 (G1) promoter, not induced by heat shock, was silent in giant cells, while Hahsp18.6G2 (G2), which responds to heat shock, was specifically induced in giant cells. In addition, a mutated Hahsp17.7G4 promoter version (G4MutP) with a strong heat-shock induction was also induced in giant cells. The responses of the different promoters correlated with distinct HSE configurations, which might have implications on differential trans-activation. Furthermore...

Mecanismos de regulación de la muerte del oocito por shock hiperosmótico

Ben Messaoud, Nabil
Fonte: [Barcelona] : Universitat Autònoma de Barcelona, Publicador: [Barcelona] : Universitat Autònoma de Barcelona,
Tipo: Tesis i dissertacions electròniques; info:eu-repo/semantics/doctoralThesis; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2014 Português
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Las proteínas quinasas p38 y JNK se activan por diversos tipos de estrés ambiental, tal como la radiación UV y el shock hiperosmótico, y regulan múltiples procesos biológicos, entre ellos la proliferación y la muerte celular. El conocimiento de algunas propiedades básicas de estas proteínas quinasas, como la ultrasensibilidad, histéresis y respuesta digital, es importante para el control de los procesos irreversibles. Resultados previos de nuestro grupo han mostrado que el estrés hiperosmótico induce apoptosis en los oocitos de Xenopus laevis y activación de las proteínas quinasas AMPK y JNK. Mediante el uso de este modelo celular, se muestra que p38 también se activa por shock hiperosmótico en los oocitos de Xenopus, que tiene un comportamiento ultrasensible, que no presenta histéresis, y que la activación a nivel de célula individual es bimodal. Por otro lado, se describe el papel de las proteínas quinasas de estrés p38 y JNK, así como la contribución de Smac/DIABLO y las calpaínas, en la apoptosis inducida por el shock hiperosmótico. La inhibición de la vía de p38 con los compuestos SB203580 o BIRB796, o bien la inhibición de la vía de JNK con SP600125, no afectan a la apoptosis inducida por el shock hiperosmótico...

Shock compression of water and solutions of ammonium nitrate

Morley, Michael James
Fonte: University of Cambridge; Department of Physics; Fracture and Shock Physics, Cavendish Laboratory; Trinity College Publicador: University of Cambridge; Department of Physics; Fracture and Shock Physics, Cavendish Laboratory; Trinity College
Tipo: Thesis; doctoral; PhD
Português
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Modern mining explosives employ solutions of ammonium nitrate, where the solution is the oxidising component of a fuel/oxidiser mixture. This thesis is primarily concerned with the shock response of water and of aqueous solutions of ammonium nitrate. Of particular interest are the temperatures induced through shock compression. An experimental facility, using a single stage gas gun in the ?plate impact? configuration, is described, along with associated experimental diagnostics. Measurements of, and improvements to, the tilt at impact are reported. The problem of shock temperature is discussed, including a brief review of the relevant literature. It is demonstrated that direct measurement of shock temperature is a complex issue that is not yet fully understood, whereas determination of temperature from an equation of state is an established technique. In a series of experiments, plate impact techniques were utilised to determine the Hugoniot and, through shock/reload experiments, the equation of state of water and aqueous solutions of ammonium nitrate. In-situ manganin gauges were used to measure stresses in the liquids and, from the arrival times of the shock wave, determine the shock velocity. Linear shock velocity?particle velocity Hugoniots for the liquids were determined...