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La0.85Sr0.15Ga0.8Mg0.2O3?δ pellets obtained by the polymeric organic complex solution method, isostatic pressing and sintering at 1350 °C have been electrical and mechanically studied. Electrical measurements evidenced reasonable ionic conductivities (0.01 S cm?1 at 800 °C), which were comparable to those reported for the La1?xSrxGa1?yMgyO3?δ prepared by other synthesis methods. On the other hand, the mechanical properties (elastic modulus, E and hardness, H) have been determined at micro/nanometric scale using the instrumented indentation technique. While E did not vary significantly with the increasing indentation depth (h), H values strongly decreased with the indentation depth up to 500 nm. For h > 500 nm, both mechanical properties remained almost constant, thus obtaining E = 271 ± 6 GPa and H = 13.2 ± 0.4 GPa. Finally, the residual imprints and fracture mechanisms have been observed by atomic force microscopy (AFM).  相似文献   
3.
An evaluation of the Technicon Axon analyser was carried out following the guidelines of the ‘Sociedad Española de Química Clínica’ and the European Committee for Clinical Laboratory Standards.A photometric study revealed acceptable results at both 340 nm and 404 nm. Inaccuracy and imprecision were lower at 404 nm than at 340 nm, although poor dispersion was found at both wavelengths, even at low absorbances. Drift was negligible, the imprecision of the sample pipette delivery system was greater for small sample volumes, the reagent pipette delivery system imprecision was acceptable and the sample diluting system study showed good precision and accuracy.Twelve analytes were studied for evaluation of the analyser under routine working conditions. Satisfactory results were obtained for within-run imprecision, while coefficients of variation for betweenrun imprecision were much greater than expected. Neither specimenrelated nor specimen-independent contamination was found in the carry-over study. For all analytes assayed, when comparing patient sample results with those obtained in a Hitachi 737 analyser, acceptable relative inaccuracy was observed.  相似文献   
4.
The synthesis and antiviral activity of a series of novel polycyclic analogues of the orthopoxvirus egress inhibitor tecovirimat (ST‐246) is presented. Several of these compounds display sub‐micromolar activity against vaccinia virus, and were more potent than cidofovir (CDV). The more active compounds were about 10‐fold more active than CDV, with minimum cytotoxic concentrations above 100 μM . Chemical manipulations of the two carbon–carbon double bonds present in the compounds were carried out to further explore the structure–activity relationships of these new polycyclic imides. Hydrogenation of the two carbon–carbon double bonds decreases antiviral activity, whereas either cyclopropanation or epoxidation of the double bonds fully eliminates the antiviral activity.  相似文献   
5.
Lipid accumulation in the human liver seems to be a crucial mechanism in the pathogenesis and the progression of non-alcoholic fatty liver disease (NAFLD). We aimed to evaluate gene expression of different fatty acid (FA) metabolism-related genes in morbidly obese (MO) women with NAFLD. Liver expression of key genes related to de novo FA synthesis (LXRα, SREBP1c, ACC1, FAS), FA uptake and transport (PPARγ, CD36, FABP4), FA oxidation (PPARα), and inflammation (IL6, TNFα, CRP, PPARδ) were assessed by RT-qPCR in 127 MO women with normal liver histology (NL, n = 13), simple steatosis (SS, n = 47) and non-alcoholic steatohepatitis (NASH, n = 67). Liver FAS mRNA expression was significantly higher in MO NAFLD women with both SS and NASH compared to those with NL (p = 0.003, p = 0.010, respectively). Hepatic IL6 and TNFα mRNA expression was higher in NASH than in SS subjects (p = 0.033, p = 0.050, respectively). Interestingly, LXRα, ACC1 and FAS expression had an inverse relation with the grade of steatosis. These results were confirmed by western blot analysis. In conclusion, our results indicate that lipogenesis seems to be downregulated in advanced stages of SS, suggesting that, in this type of extreme obesity, the deregulation of the lipogenic pathway might be associated with the severity of steatosis.  相似文献   
6.
Immobilization processes were used to chemically stabilize soil contaminated with Cu, Pb and Zn from mine tailings and industrial impoundments. We examined the effectiveness of ordinary Portland cement (OPC), phosphoric acid and MgO at immobilizing Cu, Pb and Zn in soil contaminated by either mine tailings or industrial and mine wastes. The effectiveness was evaluated using column leaching experiments and geochemical modelling, in which we assessed possible mechanisms for metal immobilization using PHREEQC and Medusa numerical codes. Experimental results showed that Cu was mobilized in all the experiments, whereas Pb immobilization with H(3)PO(4) may have been related to the precipitation of chloropyromorphite. Thus, the Pb concentrations of leachates of pure mining and industrial contaminated soils (32-410 μg/l and 430-1000 μg/l, respectively) were reduced to 1-60 and 3-360 μg/l, respectively, in the phosphoric acid experiment. The mobilization of Pb at high alkaline conditions, when Pb(OH)(4)(-) is the most stable species, may be the main obstacle to the use of OPC and MgO in the immobilization of this metal. In the mining- and industry-contaminated soil, Zn was retained by OPC but removed by MgO. The experiments with OPC showed the Zn decrease in the leachates of mining soil from 226-1960 μg/l to 92-121 μg/l. In the industrial contaminated soil, the Zn decrease in the leachates was most elevated, showing >2500 μg/l in the leachates of contaminated soil and 76-173 μg/l in the OPC experiment. Finally, when H(3)PO(4) was added, Zn was mobilized.  相似文献   
7.
Fitting a causal dynamic model to an image is a fundamental problem in image processing, pattern recognition, and computer vision. In image restoration, for instance, the goal is to recover an estimate of the true image, preferably in the form of a parametric model, given an image that has been degraded by a combination of blur and additive white Gaussian noise. In texture analysis, on the other hand, a model of a particular texture image can serve as a tool for simulating texture patterns. Finally, in image enhancement one computes a model of the true image and the residuals between the image and the modeled image can be interpreted as the result of applying a de-noising filter. There are numerous other applications within the field of image processing that require a causal dynamic model. Such is the case in scene analysis, machined parts inspection, and biometric analysis, to name only a few. There are many types of causal dynamic models that have been proposed in the literature, among which the autoregressive moving average and state-space models (i.e., Kalman filter) are the most commonly used. In this paper we introduce a 2-D stochastic state-space system identification algorithm for fitting a quarter plane causal dynamic Roesser model to an image. The algorithm constructs a causal, recursive, and separable-in-denominator 2-D Kalman filter model. The algorithm is tested with three real images and the quality of the estimated images are assessed.  相似文献   
8.
A fast and reliable method for the quantification of patulin using ultra high performance liquid chromatography coupled to a photodiode array detector was developed and validated for the analysis of several apple-based foodstuffs. Sample preparation was based on the QuEChERS procedure. Samples were extracted with acetonitrile and partitioned with a mixture of sodium citrate, NaCl, and Mg2SO4. The cleanup step was performed using dispersive SPE mixed with Mg2SO4 and PSA. This step was carried out twice in order to improve chromatographic results. The method was validated in spiked cloudy apple juice, apple puree, apple yogurt, beer with apple juice, and cider and applied to 24 commercial samples. The limits of detection and limits of quantification were ≥0.4 and ≥2 ng/g, respectively. Both were below the maximum legal limit established by the European Union. Recoveries for all the matrices were between 78.4 and 94.7 % while relative standard deviations were between 3.8 and 10.4 %. Patulin was detected on four apple juices from concentrate, one cloudy apple juice from an eco-store, and one beer. Nevertheless, the highest concentration found was 25.4 ng/g.  相似文献   
9.
In this work, electromagnetic radiation absorbent materials (ERAM) were prepared from expanded polyurethane and nano-Fe3O4. The effect of porosity and charge content on the attenuation of incident radiation was investigated using helium gas pycnometry and the waveguide technique in the frequency range of 8 to 12 GHz (X-band). ERAM were also characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and vibration sample magnetometer (VSM). Pure polyurethane absorbed 93.6% of the incident radiation at 11.8GHz. This result was attributed to its porous structure and low porosity. Although the content of open cells increases in ERAM with the increase in nanomagnetic content, materials containing 1% and 5% w/w absorbed more than 99% of the incident radiation. This behavior suggests that magnetic property of the charge is compensated for its action as a cell opener in these materials.  相似文献   
10.
We studied the effect in vitro and in vivo of dipyrone on the determination of several biochemical tests in two analyzers, a Hitachi 747 and a Kodak Ektachem 700. From studies in vitro, we found significant interference by dipyrone (P < 0.05) in the determination of creatine kinase (CK), lactate dehydrogenase (LD), uric acid, triglycerides, cholesterol, aspartate aminotransferase, alanine aminotransferase, and urea nitrogen with both instruments, and in the determination of creatinine in the Ektachem analyzer. We also studied the effect of intravenously administered dipyrone in 14 patients. Dipyrone interfered significantly (P < 0.05) in the determination of CK, LD, uric acid, triglycerides, and cholesterol with both instruments, and creatinine only with the Ektachem analyzer. Using high-performance liquid chromatography (HPLC), we measured concentrations of dipyrone in the serum of patients who had received the drug and observed a negative correlation between the concentrations of dipyrone in the blood and the percentage of each analyte concentration.  相似文献   
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