929 resultados para 1.Tetrazolium salt
Resumo:
Sodium is the most abundant extracellular cation and therefore pivotal in determining fluid balance. At the beginning of life, a positive sodium balance is needed to grow. Newborns and preterm infants tend to lose sodium via their kidneys and therefore need adequate sodium intake. Among older children and adults, however, excessive salt intake leads to volume expansion and arterial hypertension. Children who are overweight, born preterm, or small for gestational age and African American children are at increased risk of developing high blood pressure due to a high salt intake because they are more likely to be salt sensitive. In the developed world, salt intake is generally above the recommended intake also among children. Although a positive sodium balance is needed for growth during the first year of life, in older children, a sodium-poor diet seems to have the same cardiovascular protective effects as among adults. This is relevant, since: (1) a blood pressure tracking phenomenon was recognized; (2) the development of taste preferences is important during childhood; and (3) salt intake is often associated with the consumption of sugar-sweetened beverages (predisposing children to weight gain).
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A compact and planar donor–acceptor molecule 1 comprising tetrathiafulvalene (TTF) and benzothiadiazole (BTD) units has been synthesised and experimentally characterised by structural, optical, and electrochemical methods. Solution-processed and thermally evaporated thin films of 1 have also been explored as active materials in organic field-effect transistors (OFETs). For these devices, hole field-effect mobilities of μFE=(1.3±0.5)×10−3 and (2.7±0.4)×10−3 cm2 V s−1 were determined for the solution-processed and thermally evaporated thin films, respectively. An intense intramolecular charge-transfer (ICT) transition at around 495 nm dominates the optical absorption spectrum of the neutral dyad, which also shows a weak emission from its ICT state. The iodine-induced oxidation of 1 leads to a partially oxidised crystalline charge-transfer (CT) salt {(1)2I3}, and eventually also to a fully oxidised compound {1I3}⋅1/2I2. Single crystals of the former CT compound, exhibiting a highly symmetrical crystal structure, reveal a fairly good room temperature electrical conductivity of the order of 2 S cm−1. The one-dimensional spin system bears compactly bonded BTD acceptors (spatial localisation of the LUMO) along its ridge.
Resumo:
Lead is efficiently protected against cathodic corrosion by the addition of diammonium salts in the electrolyte. The cationic coating of the cathode allows the efficient electroreduction of benzamides to benzylamines. The electrochemical deoxygenation of the amide is achieved without the use of oxophilic agents or sacrificial anodes. The surface of the lead cathode stays smooth and the cathode can be reused for multiple runs, providing <2.5 ppm of the crude product. Cyclic voltammetry studies reveal a shift in the onset potential of the hydrogen evolution reaction by −157 mV.
Resumo:
A successful pregnancy requires an accommodating environment. Salt and water availability are critical for plasma volume expansion. Any changes in sodium intake would alter aldosterone, a hormone previously described beneficial in pregnancy. To date, it remains ambiguous whether high aldosterone or high salt intake is preferable. We hypothesized that increased aldosterone is a rescue mechanism and appropriate salt availability is equally effective in maintaining a normotensive blood pressure (BP) phenotype in pregnancy. We compared normotensive pregnant women (n=31) throughout pregnancy with young healthy female individuals (n=31–62) and performed salt sensitivity testing within the first trimester. Suppression of urinary tetrahydro-aldosterone levels by salt intake as measured by gas chromatography–mass spectrometry and urinary sodium excretion corrected for creatinine, respectively, was shifted toward a higher salt intake in pregnancy (P<0.0001). In pregnancy, neither high urinary tetrahydro-aldosterone nor sodium excretion was correlated with higher BP. In contrast, in nonpregnant women, systolic BP rose with aldosterone (P<0.05). Testing the impact of salt on BP, we performed salt sensitivity testing in a final cohort of 19 pregnant and 24 nonpregnant women. On salt loading, 24-hour mean arterial pressure rose by 3.6±1.5 and dropped by –2.8±1.5 mm Hg favoring pregnant women (P<0.01; χ2=6.04; P<0.02). Our data suggest first that salt responsiveness of aldosterone is alleviated in conditions of pregnancy without causing aldosterone-induced hypertension. Second, salt seems to aid in BP lowering in pregnancy for reasons incompletely elucidated, yet involving renin suppression and potentially placental sensing mechanisms. Further research should identify susceptible individuals and clarify effector mechanisms.
Resumo:
Crystal structures of organosulfur donor 2-(5′,6′-dihydro[1,3]dithiolo[4,5-b][1,4]-dithiin-2′-ylidene)-6,7-di-hydro-5H-[1,3]dithiolo[4,5-b][1,4]dithiepine-6,6-dimethanol (D) and its conducting salt D2I3 are described. Conductivity properties of D2I3 are also discussed.
Resumo:
BACKGROUND Intravenous fluids are commonly prescribed in childhood. 0.9 % saline is the most-used fluid in pediatrics as resuscitation or maintenance solution. Experimental studies and observations in adults suggest that 0.9 % saline is a poor candidate for fluid resuscitation. Although anesthesiologists, intensive care specialists, perioperative physicians and nephrologists have been the most active in this debate, this issue deserves some physiopathological considerations also among pediatricians. RESULTS As compared with so-called "balanced" salt crystalloids such as lactated Ringer, administration of large volumes of 0.9 % saline has been associated with following deleterious effects: tendency to hyperchloremic metabolic acidosis (called dilution acidosis); acute kidney injury with reduced urine output and salt retention; damaged vascular permeability and stiffness, increase in proinflammatory mediators; detrimental effect on coagulation with tendency to blood loss; detrimental gastrointestinal perfusion and function; possible uneasiness at the bedside resulting in unnecessary administration of more fluids. Nevertheless, there is no firm evidence that these adverse effects are clinically relevant. CONCLUSIONS Intravenous fluid therapy is a medicine like insulin, chemotherapy or antibiotics. Prescribing fluids should fit the child's history and condition, consider the right dose at the right rate as well as the electrolyte levels and other laboratory variables. It is unlikely that a single type of fluid will be suitable for all pediatric patients. "Balanced" salt crystalloids, although more expensive, should be preferred for volume resuscitation, maintenance and perioperatively. Lactated Ringer appears unsuitable for patients at risk for brain edema and for those with overt or latent chloride-deficiency. Finally, in pediatrics there is a need for new fluids to be developed on the basis of a better understanding of the physiology and to be tested in well-designed trials.
Resumo:
Making plants resistant to salty environments would be a boon for developing countries where poor land management has rendered large areas of arable land unfit for crop production. In a Perspective, Frommer and colleagues discuss how genetic engineering can be used to confer salt tolerance on plants ( see Apse et al.) and explore the implications of this feat for improving crop production in developing countries.
Resumo:
24 Briefe zwischen Richard Bach und Max Horkheimer, 1938-1940; 2 Briefe zwischen Alfred Chalk und Max Horkheimer, 17.10.1939, 14.11.1939; 3 Briefe von Morduch Lexandrowitsch und der American Consulate General, 1939; 4 Briefe von der American Consulate General und Max Horkheimer, 1938-1939; 1 Brief von Max Horkheimer an das Amtstgericht Berlin, 15.03.1939; 1 Brief von Max Horkheimer an Stiedry, 05.12.1938; 1 Brief von Max Horkheimer an den Collector of Custom, 26.10.1938; 2 Briefe zwischen Josef Maier und Carson Alexandrowitsch, 28.06.1938, 29.06.1938; 1 Brief von Margarete Baruch an Alice Maier, 11.04.1938; 1 Brief von Emanuel List an Carson Alexandrowitsch, 23.02.1938; 1 Abschrift des Briefes von der Metropolitan Opera Association New York an Morduch Lexandrowitsch, 22.02.1938; 1 Brief von Jacques Barzun an Max Horkheimer, 09.07.1947; 4 Briefe zwischen K. Baschwitz und Max Horkheimer, 1938-1946; 2 Briefe zwischen E. Bauer und Max Horkheimer, 08.04.1935, 27.05.1935; 4 Briefe zwischen Fritz Bauer und Max Horkheimer, 1937-1938; 2 Briefe zwischen Lina Bauer und Max Horkheimer, 20.07.1942, 16,08,1942; 4 Briefe zwsichen Rudolf Bauer und Max Horkheimer, 1937; 15 Briefe zwischen Gertrud Bauer und Max Horkheimer, 1938-1941; 1 Brief von Max Horkheimer an den Collector of Customs, 15.03.1940; 2 Briefe zwischen I. Hannah Davidson vom Jewish Community Center San Francisco und Max Horkheimer, 19.09.1938, 29.09.1938; 2 Briefe zwsichen I. Bauer und Max Horkheimer, 25.09.1938, 29.09.1938; 1 Brief von Max Horkheimer an Klopfer, 27.09.1938; 3 Briefe zwischen Y.M.H.A. - Y.W.H.A The Jewish Center of Saint Louis und Max Horkheimer, 19.09.1938, 1938; 1 Brief von Max Horkheimer an Julius Rosenberg, 17.09.1938; 1 Brief von Max Horkheimer an das Jwish Center Salt Lake City, Utah, 07.09.1938; 1 Brief von Max Horkheimer an das Jewish Community Center San Fransisco, 07.09.1938; 3 Briefe zwischen dem New York Section of the National Council of Jewish Women und Max Horkheimer, 07.04.1938, 1938; 2 Briefe zwischen Baum und Max Horkheimer, 12.03.1946, 25.05.1946; 1 Brief von Max Horkheimer an Charles A. Beard , 12.12.1934; 1 Brief von Charles A. Beard an C. A. Beard; 5 Briefe von Friedrich Pollock an Charles A. Beard, 1940-1941; 5 Briefe zwischen Lilo Beck und Max Horkheimer, 1940-1941; 7 Briefe zwischen Maximilian Beck und Max Horkheimer, 1939-1940; 1 Brief von Paul Tillich an Max Horkheimer , 01.10.1940; 1 Brief von dem Emergency Committee in Aid of Displaced Foreign Scholars New York an Max Horkheimer, 19.04.1940; 5 Briefe zwischen Konrad Bekker und Max Horkheimer, 1936-1939; 2 Briefe von Max Horkheimer an Ludwig Bendix, 1921, 1937; 1 Brief von Peter Bendmann an Max Horkheimer; 1 Brief von Max Horkheimer an Ruth Benedict, 30.07.1937; 1 Brief von Eric Russel Bentley an Max Horkheimer, 30.01.1945; 1 Brief von George Berg an Max Horkheimer, 12.07.1945; 2 Briefe zwischen Egon Bergel und Max Horkheimer, 18.08.1938, 22.08.1938; 1 Brief von Marie Jahoda an Max Horkheimer, 14.07.1928; 1 Brief von Theodor W. Adorno an Kurt Bergel, 09.09.1939; 15 Briefe zwischen Klaus Berger und Max Horkheimer, 1936-1943; 1 Brief von Frederick Pollock an Philip M. Hayden von der Columbia University New York, 05.03.1942; 1 Brief von Hans Venedey an Max Horkheimer, 05.03.1938; 1 Brief von Max Horkheimer an Ida Berger-Chevant, 18.02.1939;