Application of the parametric bootstrap method to determine statistical errors in quantitative X-ray microanalysis of thin films

We applied the parametric bootstrap to the X‐ray microanalysis of Si‐Ge binary alloys, in order to assess the dependence of the Ge concentrations and the local film thickness, obtained by using previously described Monte Carlo methods, on the precision of the measured intensities. We show how it is possible by this method to determine the statistical errors associated with the quantitative analysis performed in sample regions of different composition and thickness, but by conducting only one measurement. We recommend the use of the bootstrap for a broad range of applications for quantitative microanalysis to estimate the precision of the final results and to compare the performances of different methods to each other. Finally, we exploited a test based on bootstrap confidence intervals to ascertain if, for given X‐ray intensities, different values of the estimated composition in two points of the sample are indicative of an actual lack of homogeneity.     

Nonenzymatic Browning In Liquid Model Systems of High Water Activity: Kinetics of Color Changes Due to Reaction Between Glucose and Glycine Peptides

The rate of browning of solutions (water activity adjusted to 0.90 by adding sodium chloride) of glucose-glycine peptides (diglycine and triglycine) was well described by a “mixed-order” kinetic model having two rate coefficients, k_o and k_l. Activation energies for these parameters were calculated and compared with values for the same reaction of glucose with the amino acid (glycine). At pH below 6 the rate of browning of peptide solutions was higher than that of the amino acid (glycine) at the same molar concentration; at higher pH the reverse was observed.     

CHEMICAL COMPOSITION AND AMINO ACID CONTENTS OF BRAZILIAN BEANS (Phaseolus vulgaris)

SUMMARY— The chemical composition of 12 varieties of beans (Phaseolus vulgaris) was determined. Varieties most commonly found on Brazilian markets were chosen for this work. The average moisture content was 11%, ash 3.5%, fat 1%, protein 25%, starch 40%, crude fiber 4% and pentonsans 7%. The content of minerals in mg/100g sample was: phosphate 1000, iron 3.2, calcium 40 and magnesium 210. The content of essential amino acids in mg/g protein, calculated on a dry basis, was: lysine 72–106, threonine 46-61, valine 29–54, methionine 3–18, isoleucine 28-49, phenylalanine 33–118 and tryptophane 103-138. The product was rich in lysine and threonine as compared to the FAO table for essential amino acids require in the human diet. It was poor in methionine, isoleucine, valine, tryptophane and leucine.     

Elasticity and Anelasticity of Uranium Oxides at Room Temperature: I, Stoichiometric Oxide

The elastic modulus and internal friction of stoichiometric uranium oxide at room temperature were studied using a dynamic method. The elastic modulus of stoichiometric urania at room temperature increases with increasing density. When the volume fraction porosity is less than 0.1, either linear or exponential equations can he used to calculate the elastic modulus as a function of density. When the volume fraction porosity is more than 0.1, a linear equation seems to be more suitable. The elastic modulus of stoichiometric nonporous uranium oxide at room temperature was found, by extrapolation, to be 2243.56 ± 22.1 kbars when the exponential equation was used, and 2233.85 ± 22.05 kbars when the linear expression was used. The internal friction of stoichiometric urania decreases sharply as the grains become larger. The number, size, and position of pores may also affect the internal friction values.     

Efficacy of oral consumption of curcumin/ for symptom improvement in inflammatory bowel disease: A systematic review of animal models and a meta-analysis of randomized clinical trials

The roots of the vegetal Curcuma due to its high content of polyphenols, has been used successfully in several clinical situations. This review assessed the effect of curcumin/Curcuma longa on symptoms and metabolic changes in inflammatory bowel disease (IBD). A systematic review of animal models and randomized clinical trials (RCTs) was conducted by searching the following electronic databases: PubMed, CENTRAL, LILACS, Science Direct, and ClinicalTrials.gov. From 997 found records, 62 were included. More than 90% of the animal studies reported an improvement in macroscopic, histologic and/or functional activity; 80% identified decreased oxidative and/or inflammatory biomarkers in animals treated with curcumin. Among the RCTs, intention-to-treat analysis showed that oral curcumin was effective in inducing clinical remission (n = 281, RR: 3.15 CI 95% [1.22–8.10] p = 0.0017; i² = 72.2%, p = 0.006) and clinical response (n = 259, RR: 1.60 CI 95% [1.09–2.35] p = 0.0017; i² = 59.7%, p = 0.042) but not endoscopic remission (n = 161, RR: 2.91 CI 95% [0.58–14.58] p = 0.195; i² = 72.7%, p = 0.026). These results confirm that oral supplementation with curcumin/Curcuma longa has beneficial actions in animal colitis and, when associated with drug therapy, is effective in the treatment of patients with IBD.

     

Improvement of transfection with reprogramming factors in urinederived cells

Human-induced pluripotent stem cells (iPSCs) are an accessible source of adult-derived, patient-specific pluripotent stem cells for use in basic research, drug discovery, disease modeling, and stem cell therapy. Improving the accessibility of methods to obtain iPSCs regardless of the cell source can enhance their clinical application. Therefore, our purpose is to report a simple protocol to obtain iPS-like cells from urine-derived renal epithelial cells (RECs) using different extracellular matrices and transfection reagents. In this study, we began by culturing urine-derived cells from healthy donors to establish a primary culture of renal epithelial cells, followed by their characterization. Subsequently, we generated iPS-like cells by transfecting renal epithelial cells (RECs) with vectors expressing Oct4, Sox2, L-Myc, Lin-28, and Klf4, and we compared the efficacy of different extracellular matrices and transfection reagents. The resultant iPS-like cells showed a human embryonic stem cell-like morphology and expressed the specific pluripotency markers Oct3/4, Nanog, Lin28, and Klf4. We concluded that Lipofectamine Stem Cell transfection reagent is more effective than FuGENE in obtaining iPS-like cells under the conditions tested. Moreover, the three matrices are similar in their efficiency of obtaining iPS-like cells. This report provides an experimental protocol for obtaining and generating iPS-like cells from urine samples for further cell therapy research on different human diseases.     

SIMPLE STRUCTURE MULTILEVEL INVERTER USEFUL FOR AC MOTOR DRIVES

ABSTRACT

In this paper, a new simplified configuration for a multilevel PWM inverter and its control strategy is proposed. The proposed configuration consists of an auxiliary circuit with four switching devices, and a single full-bridge inverter. For medium power applications, the new circuit design, in which the number of switching devices is reduced, offers characteristics similar to conventional NPC inverters. The control method is based on closed loop regulation of the instantaneous line-to-line output voltages. The proposed scheme is simple, has fast response, and is effective for reducing the size of the DC-link capacitors. The performance of the system is verified by computer simulation and by practical experience