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Allochthonous salt, structure and stratigraphy of the north-eastern Gulf of Mexico. Part II: Structure

Wu, Shengyu; Bally, Albert W.; Cramez, Carlos
Fonte: Butterworth-Heinemann Ltd Publicador: Butterworth-Heinemann Ltd
Tipo: Artigo de Revista Científica
Publicado em //1990 ENG
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The Kinematic evolution of allochthonous salt in the north-eastern Gulf of Mexico proceeds in three stages. (1) Since the Middle Jurassic deposition, the Louann Salt was loaded by sediments causing episodic basinwartd movement of the salt, ultimately leading to large concentrations of salt masses in a slope environment by the end of the Lower Cretaceous. (2) A regime of starved sedimentation during Late Cretaceous and Early Oligocene is responsible for the stabilization of these early salt accumulations. (3) With renewed rapid accumulation of sediments, during the Neogene and pliocene, extensive allochthonous salt tongues and shetts formed by gravity spreading within the younger sediments of the slope. Autochthonous salt,allochthonous salt and detached allochthonous salt are typical stages of evolution. Major down to the basin growth faults separate allochthonous salt sheets from their original feeder stocks. Extension along down to the basin master growth faults in compensated mainly by salt withdrawal and partly by basinward shortening.

A comparison between sphygmomanometer-based and ambulatory blood pressure monitoring in acute salt loading and depletion protocol

PAIVA, Carlos Eduardo; AGUIAR, Andréia Fernanda Carvalho Leone; NOBRE, Fernando; COELHO, Eduardo Barbosa
Fonte: Faculdade de Medicina / USP Publicador: Faculdade de Medicina / USP
Tipo: Artigo de Revista Científica
ENG
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INTRODUCTION: Ambulatory blood pressure monitors have been used in salt loading and depletion protocols. However, the agreement between measurements made using ambulatory blood pressure monitors and those made with the sphygmomanometer has not been evaluated. OBJECTIVE: The objective of this study was to compare the concordance of the two methods of blood pressure measurements in protocols of acute salt loading and depletion. METHOD: Systolic blood pressure was measured using a sphygmomanometer at the completion of salt infusion (2 L NaCl 0.9%, 4 h) and salt depletion (furosemide, 120mg/day, p.o.) in 18 volunteers. Using the Pearson correlation coefficient (ρ), these readings were compared with the mean systolic blood pressure measured using the ambulatory blood pressure monitoring device during the following periods: 4 h of saline infusion and 12 h of salt depletion; 4 h of saline infusion and the last 6 h of salt depletion; 12 h of salt loading and the last 6 h of depletion; 12 h of salt loading and 12 h of depletion. Salt sensitivity was defined by a difference in the systolic blood pressure between salt loading and salt depletion greater than 10 mmHg when measured with the sphygmomanometer, and the Kappa analysis of concordance (K) was used with a significance level of P<0.05. RESULTS: Only the blood pressure readings obtained using the ambulatory blood pressure device during 4 h of intravenous NaCl and during 12 h of salt depletion showed a high correlation with the variation in the systolic blood pressure measured by the sphygmomanometer...

Low birth weight in response to salt restriction during pregnancy is not due to alterations in uterine-placental blood flow or the placental and peripheral renin-angiotensin system

LEANDRO, Sandra Marcia; FURUKAWA, Luzia Naoko Shinohara; SHIMIZU, Maria Heloisa Massola; CASARINI, Dulce Elena; SEGURO, Antonio Carlos; PATRIARCA, Giuliana; COELHO, Michella Soares; DOLNIKOFF, Miriam Sterman; HEIMANN, Joel Claudio
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
ENG
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A number of studies conducted in humans and in animals have observed that events occurring early in life are associated with the development of diseases in adulthood. Salt overload and restriction during pregnancy and lactation are responsible for functional (hemodynamic and hormonal) and structural alterations in adult offspring. Our group observed that lower birth weight and insulin resistance in adulthood is associated with salt restriction during pregnancy On the other hand, perinatal salt overload is associated with higher blood pressure and higher renal angiotensin II content in adult offspring. Therefore, we hypothesised that renin-angiotensin system (RAS) function is altered by changes in sodium intake during pregnancy. Such changes may influence fetoplacental blood flow and thereby fetal nutrient supply, with effects on growth in utero and, consequently, on birth weight. Female Wistar rats were fed low-salt (LS), normal-salt (NS), or high-salt (HS) diet, starting before conception and continuing until day 19 of pregnancy, Blood pressure, heart rate, fetuses and dams` body weight, placentae weight and litter size were measured on day 19 of pregnancy. Cardiac output, uterine and placental blood flow were also determined on day 19. Expressions of renin-angiotensin system components and of the TNF-alpha gene were evaluated in the placentae. Plasma renin activity (PRA) and plasma and tissue angiotensin-converting enzyme (ACE) activity...

DOCA-salt treatment enhances responses to endothelin-1 in murine corpus cavernosurn

CARNEIRO, Fernando S.; GIACHINI, Fernanda R. C.; LIMA, Victor V.; CARNEIRO, Zidonia N.; NUNES, Kenia P.; ERGUL, Adviye; LEITE, Romulo; TOSTES, Rita C.; WEBB, R. Clinton
Fonte: NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS Publicador: NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS
Tipo: Artigo de Revista Científica
ENG
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The penis is kept in the flaccid state mainly via a tonic activity of norepinephrine and endothelins (ETs). ET-1 is important in salt-sensitive forms of hypertension. We hypothesized that cavernosal responses to ET-1 are enhanced in deoxycorticosterone acetate (DOCA)-salt mice and that blockade of ETA receptors prevents abnormal responses of the corpus cavernosum in DOCA-salt hypertension. Male C57BL/6 mice were unilaterally nephrectomized and treated for 5 weeks with both DOCA and water containing 1% NaCl and 0.2% KCl. Control mice were uninephrectomized and received tap water with no added salt. Animals received either the ETA antagonist atrasentan (5 mg.day(-1).kg(-1) body weight) or vehicle. DOCA-salt mice displayed increased systolic blood pressure (SBP), and treatment with atrasentan decreased SBP in DOCA-salt mice. Contractile responses in cavernosal strips from DOCA-salt mice were enhanced by ET-1, phenylephrine, and electrical field stimulation (EFS) of adrenergic nerves, whereas relaxations were not altered by IRL-1620 (an ETB agonist), acetylcholine, sodium nitroprusside, and EFS of nonadrenergic noncholinergic nerves. PD59089 (an ERK1/2 inhibitor), but not Y-27632 (a Rho-kinase inhibitor), abolished enhanced contractions to ET-1 in cavernosum from DOCA-salt mice. Treatment of DOCA-salt mice with atrasentan did not normalize cavernosal responses. In summary...

Sobrecarga crônica de sal na dieta: mecanismos de desenvolvimento de hipertrofia ventricular esquerda em ratos Wistar machos; High salt intake: mechanisms of left ventricular hypertrophy development in male Wistar rats

Ferreira, Daniele Nunes
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 16/12/2009 PT
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O aumento da pressão arterial não é a única consequência da sobrecarga de sal na dieta. Independente dos efeitos hemodinâmicos, o excesso de sal pode induzir alterações estruturais no miocárdio. A avaliação dos mecanismos destas alterações foi o objetivo do presente estudo. Para tanto, ratos Wistar machos foram alimentados com dieta: normossódica (NR: 1,3% de NaCl), hipersódica 1 (HR1: 4%) e hipersódica 2 (HR2: 8%) desde o desmame até a 18a semana de idade. O grupo HR2 foi dividido em HR2, HR2+Hidralazina (HZ: 15mg/ kg/ dia) e HR2+Losartan (LOS: 20mg/ kg/ dia). As drogas foram administradas a partir da 7a semana de idade. Foram avaliados pressão arterial caudal (PAc), atividade de renina plasmática (ARP), aldosterona sérica, ecocardiograma, massa ventricular esquerda (MVE) e direita (MVD), medida do diâmetro transverso do miócito (DTM), fibrose intersticial (FI), expressão protéica do receptor de angiotensina II do tipo I (AT1) e tipo 2 (AT2), dosagem de angiotensina II (AII) e ligação do anticorpo que reconhece a conformação ativada dos receptores AT1 e AT2 no ventrículo esquerdo (VE) e direito (VD). A PAc foi maior no grupo HR1 e HR2 comparado com o grupo NR. A PAc do grupo HR2+HZ e HR2+LOS não diferiu do grupo NR. ARP e ALDO foram menores nos grupos HR1...

Salt-induced epithelial-to-mesenchymal transition in Dahl salt-sensitive rats is dependent on elevated blood pressure

Wang,Y.; Mu,J.J.; Liu,F.Q.; Ren,K.Y.; Xiao,H.Y.; Yang,Z.; Yuan,Z.Y.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2014 EN
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Dietary salt intake has been linked to hypertension and cardiovascular disease. Accumulating evidence has indicated that salt-sensitive individuals on high salt intake are more likely to develop renal fibrosis. Epithelial-to-mesenchymal transition (EMT) participates in the development and progression of renal fibrosis in humans and animals. The objective of this study was to investigate the impact of a high-salt diet on EMT in Dahl salt-sensitive (SS) rats. Twenty-four male SS and consomic SS-13BN rats were randomized to a normal diet or a high-salt diet. After 4 weeks, systolic blood pressure (SBP) and albuminuria were analyzed, and renal fibrosis was histopathologically evaluated. Tubular EMT was evaluated using immunohistochemistry and real-time PCR with E-cadherin and alpha smooth muscle actin (α-SMA). After 4 weeks, SBP and albuminuria were significantly increased in the SS high-salt group compared with the normal diet group. Dietary salt intake induced renal fibrosis and tubular EMT as identified by reduced expression of E-cadherin and enhanced expression of α-SMA in SS rats. Both blood pressure and renal interstitial fibrosis were negatively correlated with E-cadherin but positively correlated with α-SMA. Salt intake induced tubular EMT and renal injury in SS rats...

Effect of salt intake and potassium supplementation on brachial-ankle pulse wave velocity in Chinese subjects: an interventional study

Wang,Y.; Mu,J.J.; Geng,L.K.; Wang,D.; Ren,K.Y.; Guo,T.S.; Chu,C.; Xie,B.Q.; Liu,F.Q.; Yuan,Z.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 EN
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Accumulating evidence has suggested that high salt and potassium might be associated with vascular function. The aim of this study was to investigate the effect of salt intake and potassium supplementation on brachial-ankle pulse wave velocity (PWV) in Chinese subjects. Forty-nine subjects (28-65 years of age) were selected from a rural community of northern China. All subjects were sequentially maintained on a low-salt diet for 7 days (3.0 g/day NaCl), a high-salt diet for an additional 7 days (18.0 g/day NaCl), and a high-salt diet with potassium supplementation for a final 7 days (18.0 g/day NaCl+4.5 g/day KCl). Brachial-ankle PWV was measured at baseline and on the last day of each intervention. Blood pressure levels were significantly increased from the low-salt to high-salt diet, and decreased from the high-salt diet to high-salt plus potassium supplementation. Baseline brachial-ankle PWV in salt-sensitive subjects was significantly higher than in salt-resistant subjects. There was no significant change in brachial-ankle PWV among the 3 intervention periods in salt-sensitive, salt-resistant, or total subjects. No significant correlations were found between brachial-ankle PWV and 24-h sodium and potassium excretions. Our study indicates that dietary salt intake and potassium supplementation...

Effects of spironolactone in spontaneously hypertensive adult rats subjected to high salt intake

Baldo,Marcelo Perim; Zaniqueli,Divanei; Forechi,Ludimila; Machado,Rebeca Caldeira; Rodrigues,Sérgio Lamêgo; Mill,José Geraldo
Fonte: Faculdade de Medicina / USP Publicador: Faculdade de Medicina / USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2011 EN
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OBJECTIVE: To evaluate the effect of spironolactone on ventricular stiffness in spontaneously hypertensive adult rats subjected to high salt intake. INTRODUCTION: High salt intake leads to cardiac hypertrophy, collagen accumulation and diastolic dysfunction. These effects are partially mediated by cardiac activation of the renin-angiotensin-aldosterone system. METHODS: Male spontaneously hypertensive rats (SHRs, 32 weeks) received drinking water (SHR), a 1% NaCl solution (SHR-Salt), or a 1% NaCl solution with a daily subcutaneous injection of spironolactone (80 mg.kg-1) (SHRSalt- S). Age-matched normotensive Wistar rats were used as a control. Eight weeks later, the animals were anesthetized and catheterized to evaluate left ventricular and arterial blood pressure. After cardiac arrest, a doublelumen catheter was inserted into the left ventricle through the aorta to obtain in situ left ventricular pressurevolume curves. RESULTS: The blood pressures of all the SHR groups were similar to each other but were different from the normotensive controls (Wistar = 109±2; SHR = 118±2; SHR-Salt = 117±2; SHR-Salt-S = 116±2 mmHg; P<0.05). The cardiac hypertrophy observed in the SHR was enhanced by salt overload and abated by spironolactone (Wistar = 2.90±0.06; SHR = 3.44±0.07; SHR-Salt = 3.68±0.07; SHR-Salt-S = 3.46±0.05 mg/g; P<0.05). Myocardial relaxation...

A comparison between sphygmomanometer-based and ambulatory blood pressure monitoring in acute salt loading and depletion protocol

Paiva,Carlos Eduardo; Aguiar,Andréia Fernanda Carvalho Leone; Nobre,Fernando; Coelho,Eduardo Barbosa
Fonte: Faculdade de Medicina / USP Publicador: Faculdade de Medicina / USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2011 EN
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36.71%
INTRODUCTION: Ambulatory blood pressure monitors have been used in salt loading and depletion protocols. However, the agreement between measurements made using ambulatory blood pressure monitors and those made with the sphygmomanometer has not been evaluated. OBJECTIVE: The objective of this study was to compare the concordance of the two methods of blood pressure measurements in protocols of acute salt loading and depletion. METHOD: Systolic blood pressure was measured using a sphygmomanometer at the completion of salt infusion (2 L NaCl 0.9%, 4 h) and salt depletion (furosemide, 120mg/day, p.o.) in 18 volunteers. Using the Pearson correlation coefficient (ρ), these readings were compared with the mean systolic blood pressure measured using the ambulatory blood pressure monitoring device during the following periods: 4 h of saline infusion and 12 h of salt depletion; 4 h of saline infusion and the last 6 h of salt depletion; 12 h of salt loading and the last 6 h of depletion; 12 h of salt loading and 12 h of depletion. Salt sensitivity was defined by a difference in the systolic blood pressure between salt loading and salt depletion greater than 10 mmHg when measured with the sphygmomanometer, and the Kappa analysis of concordance (K) was used with a significance level of P<0.05. RESULTS: Only the blood pressure readings obtained using the ambulatory blood pressure device during 4 h of intravenous NaCl and during 12 h of salt depletion showed a high correlation with the variation in the systolic blood pressure measured by the sphygmomanometer...

Macroevolutionary patterns of salt tolerance in angiosperms

Bromham, L.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
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BACKGROUND: Halophytes are rare, with only 0·25% of angiosperm species able to complete their life cycle in saline conditions. This could be interpreted as evidence that salt tolerance is difficult to evolve. However, consideration of the phylogenetic distribution of halophytes paints a different picture: salt tolerance has evolved independently in many different lineages, and halophytes are widely distributed across angiosperm families. In this Viewpoint, I will consider what phylogenetic analysis of halophytes can tell us about the macroevolution of salt tolerance. HYPOTHESIS: Phylogenetic analyses of salt tolerance have shown contrasting patterns in different families. In some families, such as chenopods, salt tolerance evolved early in the lineage and has been retained in many lineages. But in other families, including grasses, there have been a surprisingly large number of independent origins of salt tolerance, most of which are relatively recent and result in only one or a few salt-tolerant species. This pattern of many recent origins implies either a high transition rate (salt tolerance is gained and lost often) or a high extinction rate (salt-tolerant lineages do not tend to persist over macroevolutionary timescales). While salt tolerance can evolve in a wide range of genetic backgrounds...

Reproductive capacity of Merino ewes fed a high-salt diet

Digby, S.; Masters, D.; Blache, D.; Blackberry, M.; Hynd, P.; Revell, D.
Fonte: Cambridge University Press Publicador: Cambridge University Press
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
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An option to increase the productivity of saline land is to graze sheep on salt-tolerant plants, which, during the summer/autumn period, can contain 20% to 25% of their dry matter as salt. This study assessed the impact of coping with high dietary salt loads on the reproductive performance of grazing ewes. From the time of artificial insemination until parturition, 2-year-old maiden Merino ewes were fed either a high-salt diet (NaCl 13% of dry matter) or control diet (NaCl 0.5% of dry matter). Pregnancy rates, lamb birth weights, milk composition and the plasma concentrations of hormones related to salt and water balance, and energy metabolism were measured. Leptin and insulin concentrations were lower (1.4 ± 0.09 v. 1.5 ± 0.12 ng/ml; (P < 0.05) and 7.2 ± 0.55 v. 8.2 ± 0.83 ng/ml; P < 0.02) in response to high-salt ingestion as was aldosterone concentration (27 ± 2.7 v. 49 ± 5.4 pg/ml; P < 0.05), presumably to achieve salt and water homeostasis. Arginine vasopressin concentration was not significantly affected by the diets, but plasma concentration of T3 differed during gestation (P < 0.02), resulting in lower concentrations in the high-salt group in the first third of gestation (1.2 ± 0.18 v. 1.3 ± 0.14 pmol/ml) and higher concentrations in the final third of gestation (0.8 ± 0.16 v. 0.6 ± 0.06 pmol/ml). T4 concentration was lower in ewes ingesting high salt for the first two-thirds of pregnancy (162 ± 8.6 v. 212 ± 13 ng/ml; P < 0.001). No substantial effects of high salt ingestion on pregnancy rates...

Offspring born to ewes fed high salt during pregnancy have altered responses to oral salt loads

Digby, S.; Masters, D.; Blache, D.; Hynd, P.; Revell, D.
Fonte: Cambridge University Press Publicador: Cambridge University Press
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
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Prenatal growth is sensitive to the direct and indirect effects of maternal dietary intake; manipulation can lead to behavioural and physiological changes of the offspring later in life. Here, we report on three aspects of how a high-salt diet during pregnancy (conception to parturition) may affect the offspring’s response to high oral salt loads: (i) dietary preferences for salt; (ii) response to salt and water balance and aldosterone and arginine vasopressin (AVP) concentrations after an oral salt challenge; (iii) concentrations of insulin and leptin after an oral salt challenge. We used two groups of lambs born to ewes fed either a high-salt (13% NaCl) diet during pregnancy (S lambs; n = 12) or control animals born to ewes fed a conventional (0.5% NaCl) diet during pregnancy (C lambs; n = 12). Lambs were subjected to short- (5 min) and long-term (24 h) preference tests for a high-salt (13% NaCl) or control diet, and the response to an oral challenge with either water or 25% NaCl solution were also carried out. Weaned lambs born to ewes fed high salt during pregnancy did not differ in their preference for dietary salt, but they did differ in their physiological responses to an oral salt challenge. Results indicate that these differences reflect an alteration in the regulation of water and salt balance as the metabolic hormones...

Dietary exposure of pregnant ewes to salt dictates how their offspring respond to salt

Chadwick, M.; Vercoe, P.; Williams, L.; Revell, D.
Fonte: Pergamon-Elsevier Science Ltd Publicador: Pergamon-Elsevier Science Ltd
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
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We investigated changes in salt preference, food and water intake, renin activity and salt excretion in adult offspring from ewes that were fed a high-salt diet (14% NaCl, high-salt offsrping) or grazed saltbush (saltbush offspring) from day 60 of pregnancy until day 21 of lactation. High-salt offspring were compared to offspring born to ewes consuming a control diet (2% NaCl) and saltbush offspring were compared to offspring from ewes which grazed a control diet of dry pasture. All offspring were weaned at 3 months of age and grazed the same clover-based pasture until testing started at 8 months of age. The preference for a low-salt diet (0.5% NaCl) when offered with an alternative (7% NaCl) did not differ between the offspring groups. High-salt offspring and saltbush offspring had a lower food intake (14% and 27% respectively) and lower water intake (35% and 20% respectively) than their control offspring. Both high-salt offspring and saltbush offspring had lower basal renin activity than their respective controls. After consuming salt, the renin activity of the saltbush offspring continued to be lower than controls whereas the renin activity of the high-salt offspring became similar to controls. In general, the saltbush offspring excreted an oral salt load more rapidly...

Salt stress or salt shock: which genes are we studying?

Shavrukov, Y.
Fonte: Oxford Univ Press Publicador: Oxford Univ Press
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
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Depending on the method of NaCl application, whether gradual or in a single step, plants may experience either salt stress or salt shock, respectively. The first phase of salt stress is osmotic stress. However, in the event of salt shock, plants suffer osmotic shock, leading to cell plasmolysis and leakage of osmolytes, phenomena that do not occur with osmotic stress. Patterns of gene expression are different in response to salt stress and salt shock. Salt stress initiates relatively smooth changes in gene expression in response to osmotic stress and a more pronounced change in expression of significant numbers of genes related to the ionic phase of salt stress. There is a considerable time delay between changes in expression of genes related to the osmotic and ionic phases of salt stress. In contrast, osmotic shock results in strong, rapid changes in the expression of genes with osmotic function, and fewer changes in ionic-responsive genes that occur earlier. There are very few studies in which the effects of salt stress and salt shock are described in parallel experiments. However, the patterns of changes in gene expression observed in these studies are consistently as described above, despite the use of diverse plant species. It is concluded that gene expression profiles are very different depending the method of salt application. Imposition of salt stress by gradual exposure to NaCl rather than salt shock with a single application of a high concentration of NaCl is recommended for genetic and molecular studies...

Die Bedeutung der renalen Nerven für die Entstehung der salz-abhängigen Hypertonie bei Dahl-Ratten; The role of renal nerves in the development of salt-induced hypertension in Dahl-rats

Richter, Stephan Christoph
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
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Dopamin spielt für die Regulierung der Nierenfunktionen eine bedeutende Rolle; hierbei werden über die bisher bekannten Dopamin-Rezeptoren unterschiedliche Effekte ausgelöst. Der funktionelle Zusammenhang dieser Dopamin-Rezeptoren mit der renalen Innervation ist erst zum Teil verstanden. So war bisher ungeklärt, ob sich bei bestimmten Tiermodellen durch die Durchtrennung der renalen Nerven eine salz-abhängige arterielle Hypertonie auslösen läßt und ob dafür möglicherweise eine Störung im renalen Dopamin-D3-Rezeptor-System verantwortlich ist. In der vorliegenden Arbeit wurde diese Arbeitshypothese untersucht. Sprague-Dawley-Ratten und Ratten der beiden Dahl-Stämme (salz-sensitiv und salz-resistent) wurden mikrochirurgisch renal denerviert. Diesen Tieren wurden jeweils scheinoperierte Tiere als Kontrollgruppen gegenübergestellt. Die Entwicklung des arteriellen Blutdruckes unter Ernährung mit normaler bzw. hoher Salzzufuhr wurde über einen längeren Zeitraum beobachtet. Zusätzlich wurden Versuche in Stoffwechselkäfigen durchgeführt, um etwaige Unterschiede der renalen Ausscheidung der verschiedenen Tiergruppen erkennen zu können. Bei normalen SD-Tieren ließ sich durch renale Denervierung eine salz-induzierte Hypertonie auslösen. Da bereits bekannt war...

Finite numerical modelling of stress deflections around salt diapirs in the Gulf of Mexico

Nokes, C. R.
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2011 EN
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This research is focused on the Northern Gulf of Mexico Mississippi Fan Delta. Deltas have a maximum horizontal stress margin parallel (extensional stress regime) at the delta top and a margin normal maximum horizontal stress (compressional stress regime) at the delta toe (King et al., 2010). The area of the delta with intrusive salt diapirs has significantly deflected maximum horizontal stresses around the salt diapirs. This is due to the contrasting geomechanical rock properties between the salt and the deltaic sediments (Zhang, 1994). A 3D seismic survey of the area with vertical salt diapirs was provided by Western Geoco. The seismic data was interpreted for the top salt-sediment contact and diapir related deformation of the sedimentary overburden. The interpretation identified six salt diapirs: four piercing by active diapirism and two piercing by reactive diapirism. 2D finite numerical models were built from representative sections of each salt diapir to predict the principal stress deflections within the sedimentary overburden adjacent the salt. The models of the reactive diapirs deflected the maximum principal stress parallel to the salt-sediment contact of the salt diapirs. The models of the active diapirs deflected the maximum principal stress normal to the salt-sediment contact of the salt diapirs. The stress orientations allowed for borehole stability diagrams to be produced for the stress orientation above the diapir crests...

Análisis de ciclo de vida de los procesos de extracción y purificación de la salmuera del proceso cloro-álcali; Life cycle assessment of salt mining and brine purification for the chlor-alkali process

Herrero González, Marta
Fonte: Universidade de Cantabria Publicador: Universidade de Cantabria
Tipo: Dissertação de Mestrado
SPA
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RESUMEN: La industria cloro-álcali hace referencia a aquella que produce cloro, hidróxido sódico, e hidrógeno como subproducto. Esta industria tiene una gran importancia a nivel productivo y económico, alcanzando en el año 2014 en Europa las 9.6 Mt/año de Cl2 en las 73 plantas de cloro-álcali, localizadas en 21 países diferentes. España también cuenta con una relativa importancia en este sector, con 9 plantas situadas mayoritariamente en el norte de la península (Euro Chlor, 2015). El proceso cloro-álcali comienza con la obtención de la sal (NaCl), la cual es transportada a la planta y utilizada en la preparación de la salmuera, que debe ser purificada antes de introducirse en electrólisis. La obtención la sal puede realizarse por diversas vías: minería de sal de roca, extracción por disolución, evaporación solar de sal, purificación de residuos de KCl, y producción de sal a vacío (Euro Chlor, 2013). Respecto a la electrolisis, se pueden emplear tres tecnologías diferentes: mercurio, membrana y diafragma. En dichas celdas, mediante la aplicación de una corriente eléctrica, se consigue la ruptura de la molécula de NaCl. Existen diversos estudios que realizan un análisis de ciclo de vida al proceso cloro-álcali (Euro Chlor...

High dietary salt during pregnancy in ewes alters the responses of offspring to an oral salt challenge.

Digby, Serina
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2007
Relevância na Pesquisa
36.75%
Most research to date has focused on non-pregnant sheep grazing saltbush to fill the summer/autumn feed gap in temperate regions of southern Australia. However, the summer/autumn period coincides with late pregnancy for autumn- or winter-lambing ewes, and feeding saltbush may reduce the amount and cost of supplementary feed that is required to meet the energy demands of late pregnancy. The challenge of dealing with a high-salt diet may be exacerbated during pregnancy since pregnancy is a salt-retaining physiological state, yet a high-salt intake requires an increase in mechanisms to excrete salt. The effect of high dietary salt on the developing foetus(es) has been studied in rodent models, but less so in sheep. Hence the aims of this thesis were to determine whether pregnant ewes can manage a high dietary salt content resembling that found in saltbush, and whether there are consequences to the offspring’s physiological responses to ingested salt. Merino ewes were synchronized for ovulation and artificially inseminated. To mimic the concentration of salt in animals grazing saltbush-based pastures in summer and autumn, a diet of 13% NaCl was fed from insemination through to parturition. It was found that pregnant ewes can be fed a 13% NaCl diet and manage the physiological conflict of high salt and pregnancy by decreasing their aldosterone concentrations and increasing their water consumption. There was no effect of high dietary salt on pregnancy rates...

"Efeitos da sobrecarga ou restrição crônica de sal na dieta durante a gestação e amamentação em ratas Wistar e sua repercussão sobre a prole".; Renin-angiotensin system function and blood pressure in adult rats after perinatal salt overload

Silva, Alexandre Alves da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 19/04/2001 PT
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Alguns estudos têm procurado avaliar os efeitos de variações no consumo de sal no período perinatal sobre o sistema cardiovascular da prole na idade adulta. No entanto, várias questões ainda estão em aberto e merecem estudos adicionais. Neste trabalho, o OBJETIVO foi estudar os efeitos da sobrecarga ou restrição crônica de sal na dieta de ratas Wistar, durante a gestação e amamentação, sobre o ganho de peso, a pressão arterial, a sensibilidade da pressão arterial ao sal (SENS), a atividade do sistema renina-angiotensina, o conteúdo renal de angiotensina II (AII) e a densidade glomerular da prole na idade adulta. Foram utilizadas fêmeas Wistar recém desmamadas divididas em 3 grupos: dieta hipo (HO - 0,15% NaCl - n=8), normo (NR - 1,27% NaCl - n=9) ou hipersódica (HR – 7,94% NaCl - n=8). A quantidade de dieta oferecida as ratas foi ajustada de forma a manter o peso semelhante entre os grupos. A fecundação ocorreu na 12a semana de idade. Após o parto, apenas 8 recém-nascidos (4 machos e 4 fêmeas) permaneceram com suas mães. Após o desmame, todos os animais da prole receberam apenas a dieta NR. O peso materno foi medido diariamente até a fecundação e semanalmente até uma semana após o parto. O peso da prole foi medido no dia do parto e semanalmente após o desmame. A PA caudal materna foi medida desde uma semana antes da fecundação até uma semana após o parto (PAc-M) e na prole entre a 8a e a 12a semana de idade (PAc-P). Ao completar 12 semanas de idade...

A comparison between sphygmomanometer-based and ambulatory blood pressure monitoring in acute salt loading and depletion protocol

Paiva, Carlos Eduardo; Aguiar, Andréia Fernanda Carvalho Leone; Nobre, Fernando; Coelho, Eduardo Barbosa
Fonte: Universidade de São Paulo. Faculdade de Medicina Publicador: Universidade de São Paulo. Faculdade de Medicina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; ; Formato: application/pdf
Publicado em 01/01/2011 ENG
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INTRODUCTION: Ambulatory blood pressure monitors have been used in salt loading and depletion protocols. However, the agreement between measurements made using ambulatory blood pressure monitors and those made with the sphygmomanometer has not been evaluated. OBJECTIVE: The objective of this study was to compare the concordance of the two methods of blood pressure measurements in protocols of acute salt loading and depletion. METHOD: Systolic blood pressure was measured using a sphygmomanometer at the completion of salt infusion (2 L NaCl 0.9%, 4 h) and salt depletion (furosemide, 120mg/day, p.o.) in 18 volunteers. Using the Pearson correlation coefficient (ρ), these readings were compared with the mean systolic blood pressure measured using the ambulatory blood pressure monitoring device during the following periods: 4 h of saline infusion and 12 h of salt depletion; 4 h of saline infusion and the last 6 h of salt depletion; 12 h of salt loading and the last 6 h of depletion; 12 h of salt loading and 12 h of depletion. Salt sensitivity was defined by a difference in the systolic blood pressure between salt loading and salt depletion greater than 10 mmHg when measured with the sphygmomanometer, and the Kappa analysis of concordance (K) was used with a significance level of P