981 resultados para [day] [water layer with no specific feature]


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Over the last two decades, ionic liquids have gained importance as alternative solvents to conventional VOCs in the field of homogeneous catalysis. This success is not only due to their ability to dissolve a large amount of metal catalysts, but it is also due to their potential to enhance yields of enantiopure products. The art of preparation of a specific enantiomer is a highly desired one and searched for in pharmaceutical industry. This work presents a study on solubility in water and in water/methanol mixture of a set of ILs composed of the bis (trifluoromethylsulfonyl) imide anion and of the N-alkyl-triethyl-ammonium cation (abbrev. [NR,222][NTf2]) with the alkyl chain R ranging from 6 to 12 carbons. Mutual solubilities between ILs and water, as well as between ILs and methanol/water mixture were investigated in detail. These solubilities were measured using two well-known and accurate experimental techniques based on a volumetric and a cloud-point methods. Both methods enabled us to measure the Tx diagrams reflecting the mutual solubilities between water (or water/methanol) and selected ILs in the temperature range from 293.15 to 338.15 K. The data were fitted by using the modified Flory-Huggins equation proposed by de Sousa and Rebelo and compared also with the prediction carried out by the Cosmo-RS methodology

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<p>Optical signals measured in apertureless scanning near field optical microscopy (ASNOM) under ambient conditions are found to be affected significantly by the thin water layer absorbed on the surface under investigation, the presence of which is detected through measurements of the shear force experienced by the tip. This water layer also results in a large hysteresis between optical signals measured during approach and withdrawal of the tip to the sample surface. The role of this effect in ASNOM is anticipated to be significant, with the possibility of resultant topographically induced artefacts for ASNOM involving intermittent contact of tip and sample, but also providing a potential mechanism for nanoscale optical resolution.p>

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A morphological instability of a mushy layer due to a forced flow in the melt is analysed. The instability is caused by flow induced in the mushy layer by Bernoulli suction at the crests of a sinusoidally perturbed mush–melt interface. The flow in the mushy layer advects heat away from crests which promotes solidification. Two linear stability analyses are presented: the fundamental mechanism for instability is elucidated by considering the case of uniform flow of an inviscid melt; a more complete analysis is then presented for the case of a parallel shear flow of a viscous melt. The novel instability mechanism we analyse here is contrasted with that investigated by Gilpin et al. (1980) and is found to be more potent for the case of newly forming sea ice.

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This paper examines the role of the Arctic Ocean Atlantic water (AW) in modifying the Laptev Sea shelf bottom hydrography on the basis of historical records from 1932 to 2008, field observations carried out in April–May 2008, and 2002–2009 crossslope measurements. A climatology of bottom hydrography demonstrates warming that extends offshore from the 30–50 m depth contour. Bottom layer temperaturetime series constructed from historical records links the Laptev Sea outer shelf to the AW boundary current transporting warm and saline water from the North Atlantic. The AW warming of the mid‐1990s and the mid‐2000s is consistent with outer shelf bottom temperature variability. For April–May 2008 we observed on‐shelf near‐bottom warm and saline water intrusions up to the 20 m isobath. These intrusions are typically about 0.2°C warmer and 1–1.5 practical salinity units saltier than ambient water. The 2002–2009 crossslope observations are suggestive for the continental slope upward heat flux from the AW to the overlying lowhalocline water (LHW). The lateral on‐shelf winddriven transport of the LHW then results in the bottom layer thermohaline anomalies recorded over the Laptev Sea shelf. We also found that polynyainduced vertical mixing may act as a drainage of the bottom layer, permitting a relatively small portion of the AW heat to be directly released to the atmosphere. Finally, we see no significant warming (up until now) over the Laptev Sea shelf deeper than 10–15 m in the historical record. Future climate change, however, may bring more intrusions of Atlantic‐modified waters with potentially warmer temperature onto the shelf, which could have a critical impact on the stability of offshore submarine permafrost.

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This project was performed at Rochester Institute of Technology to get more understanding and knowledge about AM and FM screenings similarities and differences with considerations of the mottle. By designing a test form conformed to the specific measurements and printing it on Heidelberg's Sunday 2000 press, the project group has evaluated the questions that already existed and the ones that occurred during the project. Hence the first press run left some unexpected phenomenon therefore another press run was performed. Measurements were performed and graphs produced in Excel. The project group evaluated the results and from that able to establish facts and draw conclusions. It has been a great experience for the project group and they have learnt a lot.

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Introduction/hypothesisr />Cardiac hypertrophy is an independent risk factor predictive of cardiovascular disease and is significantly associated with morbidity and mortality. The mechanism by which angiotensin II (Ang II) and dietary sodium exert additive effects on the development of cardiac hypertrophy is unclear. The goal of this study was to evaluate the hypothesis that, where there is a genetic predisposition to Ang II-dependent hypertrophy, there is also an increased susceptibility to sodium-induced hypertrophy mediated by AT<sub>1sub>-receptor expression.r />r />Methodsr />Diets of low sodium (LS, 0.3% w:w) and high sodium (HS, 4.0% w:w) content were fed to adult (age 25 weeks) control wild-type mice (WT) and to weeks) control wild-type mice (WT) and to transgenic mice exhibiting cardiac specific overexpression of angiotensinogen (TG). At the conclusion of a 40-day dietary treatment period, cardiac tissue weights were compared and the relative expression levels of Ang II receptor subtypes (AT<sub>1Asub> and AT<sub>2sub>) were evaluated using RT-PCR.r />r />Resultsr />WT and TG mice fed HS and LS diets maintained comparable weight gains during the treatment period. The normalised heart weights of TG mice were elevated compared to WT, and the extent of the increase was greater for mice maintained on the HS diet treatments (WT 12% vs. TG 41% increase in cardiac weight index). While a similar pattern of growth was observed for ventricular tissues, the atrial weight parameters demonstrated an additional significant effect of dietary sodium intake on tissue weight, independent of animal genetic type. No differences in the relative (GAPDH normalised) expression levels of AT<sub>1Asub>- and AT<sub>2sub>-receptor mRNA were observed between diet or animal genetic groups.r />r />Conclusionr />This study demonstrates that, where there is a pre-existing genetic condition of Ang II-dependent cardiac hypertrophy, the pro-growth effect of elevated dietary sodium intake is selectively augmented. In TG and WT mice, this effect was evident with a relatively short dietary treatment intervention (40 days). Evaluation of the levels of Ang II receptor mRNA further demonstrated that this differential growth response was not associated with an altered relative expression of either AT<sub>1Asub>- or AT<sub>2sub>-receptor subtypes. The cellular mechanistic bases for this specific Ang II-dietary sodium interaction remain to be elucidated.r />

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Rapid in vitro methods for measuring digestibility may be useful in analysing aqua feeds if the extent and limits of their application are clearly defined. The pH-stat protein digestibility routine with shrimp hepatopancreas enzymes was previously related to apparent protein digestibility with juvenile Litopenaeus vannamei fed diets containing different protein ingredients. The potential of the method to predict culture performance of shrimp fed six commercial feeds (T3, T4, T5, T6, T7 and T8) with 350 g kg(-1) declared crude-protein content was assessed. The consistency of results obtained using hepatopancreas enzyme extracts from either pond or clear water-raised shrimp was further verified in terms of reproducibility and possible diet history effects upon in vitro outputs. Shrimps were previously acclimated and then maintained over 56 days (initial mean weight 3.28 g) on each diet in 500-L tanks at 114 ind m(-2), clear water closed system with continuous renewal and mechanical filtering (50 mu m), with four replicates per treatment. Feeds were offered four times daily (six days a week) delivered in trays at feeding rates ranging from 4.0% to 7.0% of stocked shrimp biomass. Feed was accessible to shrimp 4 h daily for 1-h feeding period after which uneaten feed was recovered. Growth and survival were determined every 14 days from a sample of 16 individuals per tank. Water quality was monitored daily (pH, temperature and salinity) and managed by water back flushing filter cleaning every 7-10 days. Feeds were analysed for crude protein, gross energy, amino acids and pepsin digestibility. In vitro pH-stat degree of protein hydrolysis (DH%) was determined for each feed using hepatopancreas enzyme extracts from experimental (clear water) or pond-raised shrimp. Feeds resulted in significant differences in shrimp performance (P < 0.05) as seen by the differences in growth rates (0.56-0.98 g week(-1)), final weight and feed conversion ratio (FCR). Shrimp performance and in vitro DH% with pond-raised shrimp enzymes showed significant correlation (P < 0.05) for yield (R-2 = 0.72), growth rates (R-2 = 0.72-0.80) and FCR (R-2 = -0.67). Other feed attributes (protein : energy ratio, amino acids, true protein, non-protein nitrogen contents and in vitro pepsin digestibility) showed none or limited correlation with shrimp culture performance. Additional correlations were found between growth rates and methionine (R-2 = 0.73), FCR and histidine (R-2 = -0.60), and DH% and methionine or methionine+cystine feed contents (R-2 = 0.67-0.92). pH-stat assays with shrimp enzymes generated reproducible DH% results with either pond (CV <= 6.5%) or clear water (CV <= 8.5%) hepatopancreas enzyme sources. Moreover, correlations between shrimp growth rates and feed DH% were significant regardless of the enzyme origin (pond or clear water-raised shrimp) and showed consistent R-2 values. Results suggest the feasibility of using standardized hepatopancreas enzyme extracts for in vitro protein digestibility.

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Neonatal cattle and in part neonates of other species have manyfold higher plasma concentrations of nitrite plus nitrate than mature cows and subjects of other species, suggesting an enhanced and needed activation of the nitric oxide (NO) axis at birth. While the biological half-life of NO is short (<1 sec), its functionality can be prolonged, and in many regards more discretely modulated, when it reacts with low-molecular-weight and protein-bound thiols to form S-nitrosothiols (RSNO), from which NO subsequently can be rereleased. We used the calf as a model to test the hypothesis that plasma concentrations of RSNO are elevated at birth in mammals, correlate with ascorbate and urate levels, are selectively generated in critical tissue beds, and are generated in a manner temporally coincident with changes in tissue levels of active NO synthases (NOS). Plasma concentrations of RSNO, ascorbate, and urate were highest immediately after birth (Day 0), dropped >50% on Day 1, and gradually decreased over time, reaching a nadir in mature cattle. Albumin and immunoglobulin G were identified as major plasma RSNO. The presence of S-nitrosocysteine (SNC, a validated marker for S-nitrosylated proteins), inducible NOS (iNOS), and activated endothelial NOS (eNOS phosphorylated at Ser1177) in different tissues was analyzed by immunohistochemistry in another group of similar-aged calves. SNC, iNOS, and phosphorylated eNOS were detected in liver and ileum at the earliest timepoint of sampling (4 hrs after birth), increased between 4 and 24 hrs, and then declined to near-nondetectable levels by 2 weeks of life. Our data show that the neonatal period in the bovine species is characterized by highly elevated and coordinated NO-generating and nitrosylation events, with the ontogenetic changes occurring in iNOS and eNOS contents in key tissues as well as RSNO products and associated antioxidant markers.

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BACKGROUND Since drug-related emergency department (ED) visits are common among older adults, the objectives of our study were to identify the frequency of drug-related problems (DRPs) among patients presenting to the ED with non-specific complaints (NSC), such as generalized weakness and to evaluate responsible drug classes. METHODS Delayed type cross-sectional diagnostic study with a prospective 30 day follow-up in the ED of the University Hospital Basel, Switzerland. From May 2007 until April 2009, all non-trauma patients presenting to the ED with an Emergency Severity Index (ESI) of 2 or 3 were screened and included, if they presented with non-specific complaints. After having obtained complete 30-day follow-up, two outcome assessors reviewed all available information, judged whether the initial presentation was a DRP and compared their judgment with the initial ED diagnosis. Acute morbidity ("serious condition") was allocated to individual cases according to predefined criteria. RESULTS The study population consisted of 633 patients with NSC. Median age was 81 years (IQR 72/87), and the mean Charlson comorbidity index was 2.5 (IQR 1/4). DRPs were identified in 77 of the 633 cases (12.2%). At the initial assessment, only 40% of the DRPs were correctly identified. 64 of the 77 identified DRPs (83%) fulfilled the criteria "serious condition". Polypharmacy and certain drug classes (thiazides, antidepressants, benzodiazepines, anticonvulsants) were associated with DRPs. CONCLUSION Elderly patients with non-specific complaints need to be screened systematically for drug-related problems. TRIAL REGISTRATION ClinicalTrials.gov: NCT00920491.

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Using miniature thermistors with integrated data loggers, the decrease in summer lake surface water temperature (LSWT) with increasing altitude a.s.l. was investigated in 10 Swiss Alpine lakes located between 613 m a.s.l. and 2339 m a.s.l. The LSWTs exhibit essentially the same short-term structure as regional air temperature, but are about 3 to 5°C higher than the air temperature at the altitude of the lake. LSWTs decrease approximately linearly with increasing altitude at a rate slightly greater than the surface air temperature lapse rate. Diel variations in LSWT are large, implying that single water temperature measurements are un- likely to be representative of the mean. Local factors will affect LSWT more than they affect air temperature, possibly resulting in severe distortion of the empirical relationship between the two. Several implications for paleoclimate reconstruction studies result. (1) Paleolimnologically reconstructed LSWTs are likely to be higher than the air temperatures prevailing at the altitude of the lake. (2) Lakes used for paleoclimate reconstruction should be selected to minimize local effects on LSWT. (3) The calibration of organism-specific quantitative paleotemperature inference models should not be based on single water temperature measurements. (4) Consideration should be given to calibrating such models directly against air temperature rather than water temperature. (5) The primary climate effect on the aquatic biota of high-altitude lakes may be mediated by the timing of the ice cover.

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Three dives of the Mir manned submersibles with plankton counts and two vertical plankton hauls with a BR net were carried out above the Lost City (Atlantis underwater massif) and the Broken Spur hydrothermal fields during cruise 50 of R/V Akademik Mstislav Keldysh. Above the Atlantis seamount no significant increase in plankton concentration was found. Above the Lost City field horizontal heterogeneity of plankton distribution in the near-bottom layer and in overlying water layers was shown. Near-bottom aggregations of euphausiids and amphipods previously reported by other scientists seem to be related to attraction of these animals by the submersible's headlights rather than represent a natural phenomenon.