Defining Nafion Ionomer Roles for Enhancing Alkaline Oxygen Evolution Electrocatalysis

The electrocatalytic oxygen evolution reaction (OER) is not strictly a surface reaction, because it takes place in a thin hydrous electrical double layer (EDL). In this work, we perform an in-depth study of Nafion ionomer functions in both catalyst inks and catalyst layers (CL) for high-efficiency OER in alkaline media. Based on cyclic voltammetry results, an analysis method is developed to characterize pseudocapacitance and EDL charging capacitance independently. This enables accurate quantification of interfacial charge transport behavior and active sites for OER. Zeta potential measurements confirm that Nafion ionomer serves as a stabilizing and binding agent in catalyst-solvent inks. The data obtained from the half-cell tests in 1 M KOH reveal that increasing ionomer content in CL reduces OER performance due to higher mass transport resistance and less active sites. The sample with I/C = 1/24 (weight ratio of Nafion ionomer to IrOx catalyst) exhibits an approximately 1.7-times higher OER activity than that of I/C = 2/1. Furthermore, the ionomer blocking effect is found to be a common phenomenon, which was observed in a wide range of catalyst loadings and three different catalyst materials. Nevertheless, as demonstrated by Nafion-free samples, the addition of Nafion is indispensable for efficient catalyst utilization. Our study shows that the optimized ionomer content in the CL is 10-30 wt % of catalyst loading. Within this range, Nafion, catalyst particles, and electrolyte solution form efficient interaction, resulting in good connectivity of the charge conduction paths without inhibiting the gas diffusion

Using Phylogenomic Data to Explore the Effects of Relaxed Clocks and Calibration Strategies on Divergence Time Estimation: Primates as a Test Case.

Primates have long been a test case for the development of phylogenetic methods for divergence time estimation. Despite a large number of studies, however, the timing of origination of crown Primates relative to the Cretaceous-Paleogene (K-Pg) boundary and the timing of diversification of the main crown groups remain controversial. Here, we analysed a data set of 372 taxa (367 Primates and 5 outgroups, 3.4 million aligned base pairs) that includes nine primate genomes. We systematically explore the effect of different interpretations of fossil calibrations and molecular clock models on primate divergence time estimates. We find that even small differences in the construction of fossil calibrations can have a noticeable impact on estimated divergence times, especially for the oldest nodes in the tree. Notably, choice of molecular rate model (autocorrelated or independently distributed rates) has an especially strong effect on estimated times, with the independent rates model producing considerably more ancient age estimates for the deeper nodes in the phylogeny. We implement thermodynamic integration, combined with Gaussian quadrature, in the program MCMCTree, and use it to calculate Bayes factors for clock models. Bayesian model selection indicates that the autocorrelated rates model fits the primate data substantially better, and we conclude that time estimates under this model should be preferred. We show that for eight core nodes in the phylogeny, uncertainty in time estimates is close to the theoretical limit imposed by fossil uncertainties. Thus, these estimates are unlikely to be improved by collecting additional molecular sequence data. All analyses place the origin of Primates close to the K-Pg boundary, either in the Cretaceous or straddling the boundary into the Palaeogene

The role of disturbance waves in nucleate boiling in annular flow

In annular two-phase gas-liquid flow, the liquid film on the wall consists of relatively quiescent substrate regions which are traversed by large amplitude, high velocity waves known as disturbance waves. The turbulent disturbance wave regions have relatively high average heat transfer coefficients (low average wall temperatures) compared to the (probably laminar) substrate regions. Nevertheless, there is evidence that nucleate boiling (necessitating a higher wall temperature) occurs first in the wave regions. This paper explores the hypothesis that wall temperature fluctuations due to turbulence in the disturbance waves are of sufficient magnitude to give localized triggering of nucleation sites and hence nucleate boiling. This hypothesis was explored using Computational Fluid Dynamics (CFD). The turbulence was modelled using wall-resolved LES. The results lend weight to the hypothesis that the nucleate boiling observed in disturbance waves is due to transient local high temperatures induced by the turbulence

The Minimal Solution to the mu/B_mu Problem in Gauge Mediation

We provide a minimal solution to the mu/B_mu problem in the gauge mediated supersymmetry breaking by introducing a Standard Model singlet filed S with a mass around the messenger scale which couples to the Higgs and messenger fields. This singlet is nearly supersymmetric and acquires a relatively small Vacuum Expectation Value (VEV) from its radiatively generated tadpole term. Consequently, both mu and B_mu parameters receive the tree-level and one-loop contributions, which are comparable due to the small S VEV. Because there exists a proper cancellation in such two kinds of contributions to B_mu, we can have a viable Higgs sector for electroweak symmetry breaking.Comment: 15 pages, 2 figures, version published on JHE

p38 Mapk signal pathway involved in anti-inflammatory effect of chaihu-shugan-san and shen-ling-bai-zhu-san on hepatocyte in non-alcoholic steatohepatitis rats

Background: Traditional Chinese Medicine (TCM), has over thousands-of-years history of use. Chaihu-Shugan-San (CSS), and Shen-ling-bai-zhu-San (SLBZS), are famous traditional Chinese herbal medicine formulas, which have been used in China, for the treatment of many chronic diseases.Materials and Methods:This study investigated the anti-inflammatory effects of CSS and SLBZS on signaling molecules involved in p38 mitogen-activated protein kinase (p38 MAPK), pathway on hepatocytes of non-alcoholic steatohepatitis (NASH), rats induced by high fat diet. SD male rats were randomly divided into 8 groups: negative control group, model control group, high (9.6g/kg/day)/low (3.2g/kg/day)-dose CSS group, high (30g/kg/day)/low (10g/kg/day)-dose SLBZS group, high (39.6g/kg/day)/low (13.2g/kg/day)-dose integrated group. The rats of NASH model were induced by feeding a high-fat diet. After 16, wks, Hepatocytes were isolated from 6, rats in each group by collagenase perfusion. The liver histopathological changes and serum inflammatory cytokines TNF-α, IL-6 were determined. The proteins of TLR4,  phosphor-p38 MAPK and p38 MAPK involved in p38 MAPK signal pathway were assayed.Results: The statistical data indicated the NASH model rats reproduced typical histopathological features of NASH in human. CSS and SLBZS ameliorated lipid metabolic disturbance, attenuated NASH progression, decreased the levels of TNF-α and IL-6 in serum, as well as inhibited TLR4 protein expression, p38 MAPK phosphorylation, and activation of p38 MAPK. In conclusion, CSS and SLBZS might work as a significant anti-inflammatory effect on hepatocyte of NASH by inhibiting the activation of TLR4, p-p38 MAPK and p38 MAPK involved in p38 MAPK signal pathway.Conclusion: To some extent, CSS and SLBZS may be a potential alternative and complementary medicine to protect against liver injury, alleviate the inflammation reaction, moderate NASH progression.Key words: p38 mitogen-activated protein kinase; Toll like receptor 4; Hepatocytes; Non-alcoholic Steatohepatitis; Traditional Chinese medicine

CHD1L protein is overexpressed in human ovarian carcinomas and is a novel predictive biomarker for patients survival

published_or_final_versio

Learning and Matching Multi-View Descriptors for Registration of Point Clouds

Critical to the registration of point clouds is the establishment of a set of accurate correspondences between points in 3D space. The correspondence problem is generally addressed by the design of discriminative 3D local descriptors on the one hand, and the development of robust matching strategies on the other hand. In this work, we first propose a multi-view local descriptor, which is learned from the images of multiple views, for the description of 3D keypoints. Then, we develop a robust matching approach, aiming at rejecting outlier matches based on the efficient inference via belief propagation on the defined graphical model. We have demonstrated the boost of our approaches to registration on the public scanning and multi-view stereo datasets. The superior performance has been verified by the intensive comparisons against a variety of descriptors and matching methods

Intensive expression of Bmi-1 is a new independent predictor of poor outcome in patients with ovarian carcinoma

Background: It has been suggested that the B-cell specific moloney leukemia virus insertion site 1 (Bmi-1) gene plays an oncogenic role in several types of human cancer, but the status of Bmi-1 amplification and expression in ovarian cancer and its clinical/prognostic significance are unclear.Methods: The methods of immunohistochemistry and fluorescence in situ hybridization were utilized to examine protein expression and amplification of Bmi-1 in 30 normal ovaries, 30 ovarian cystadenomas, 40 borderline ovarian tumors and 179 ovarian carcinomas.Results: Intensive expression of Bmi-1 was detected in none of the normal ovaries, 3% cystadenomas, 10% borderline tumors, and 37% ovarian carcinomas, respectively. Amplification of Bmi-1 was detected in 8% of ovarian carcinomas. In ovarian carcinomas, significant positive associations were found between intensive expression of Bmi-1 and the tumors ascending histological grade, later pT/pN/pM and FIGO stages (P < 0.05). In univariate survival analysis of the ovarian carcinoma cohorts, a significant association of intensive expression of Bmi-1 with shortened patient survival (mean 49.3 months versus 100.3 months, p < 0.001) was demonstrated. Importantly, Bmi-1 expression provided significant independent prognostic parameters in multivariate analysis (p = 0.005).Conclusions: These findings provide evidence that intensive expression of Bmi-1 might be important in the acquisition of an invasive and/or aggressive phenotype of ovarian carcinoma, and serve as a independent biomarker for shortened survival time of patients. © 2010 Yang et al; licensee BioMed Central Ltd.published_or_final_versio

Maca (L. meyenii) for improving sexual function: a systematic review

<p>Abstract</p> <p>Background</p> <p>Maca (<it>Lepidium meyenii</it>) is an Andean plant of the brassica (mustard) family. Preparations from maca root have been reported to improve sexual function. The aim of this review was to assess the clinical evidence for or against the effectiveness of the maca plant as a treatment for sexual dysfunction.</p> <p>Methods</p> <p>We searched 17 databases from their inception to April 2010 and included all randomised clinical trials (RCTs) of any type of maca <it/>compared to a placebo for the treatment of healthy people or human patients with sexual dysfunction. The risk of bias for each study was assessed using Cochrane criteria, and statistical pooling of data was performed where possible. The selection of studies, data extraction, and validations were performed independently by two authors. Discrepancies were resolved through discussion by the two authors.</p> <p>Results</p> <p>Four RCTs met all the inclusion criteria. Two RCTs suggested a significant positive effect of maca on sexual dysfunction or sexual desire in healthy menopausal women or healthy adult men, respectively, while the other RCT failed to show any effects in healthy cyclists. The further RCT assessed the effects of maca in patients with erectile dysfunction using the International Index of Erectile Dysfunction-5 and showed significant effects.</p> <p>Conclusion</p> <p>The results of our systematic review provide limited evidence for the effectiveness of maca in improving sexual function. However, the total number of trials, the total sample size, and the average methodological quality of the primary studies were too limited to draw firm conclusions. More rigorous studies are warranted.</p

Leisure-Time Sedentary Behavior, Alcohol Consumption, and Sexual Intercourse Among Adolescents Aged 12-15 Years in 19 Countries From Africa, the Americas, and Asia

BACKGROUND: The association between sedentary behavior and sexual behavior has not been investigated among adolescents. // AIM: The aim of this study was to: (i) investigate the association between leisure-time sedentary behavior and sexual intercourse, and (ii) test for mediation by alcohol consumption, drug use, physical activity, bullying victimization, parental support/ monitoring, loneliness, and depressive symptoms in a large global sample of young adolescents. // METHODS: Data were analyzed from 34,674 adolescents aged 12-15 years participating in the Global School-based Student Health Survey. Participants reported the number of hours spent in leisure-time sedentary behavior on a typical day (8 hours). Data on alcohol consumption, drug use, physical activity, bullying victimization, parental support/monitoring, loneliness, and depressive symptoms were considered as potential mediators. // OUTCOME: Participants reported whether or not they had sexual intercourse in the past 12 months (yes/no). // RESULTS: The prevalence of past 12-month sexual intercourse was 11.9%, whereas the prevalence of 8 hours per day of leisure-time sedentary behavior were 26.7%, 35.6%, 21.4%, 11.5%, and 4.9%, respectively. There was a dose-dependent relationship between sedentary behavior and odds of reporting sexual intercourse: compared with 8 hours/day of sedentary behavior were 1.12 (0.94-1.33), 1.22 (1.01-1.48), 1.34 (1.08-1.66), and 1.76 (1.37-2.27), respectively. There was no significant interaction by sex. The largest proportion of the association between sedentary behavior and sexual intercourse was explained by alcohol use (% mediated 21.2%), with other factors explaining an additional 11.2%. // CLINICAL TRANSLATION: Interventions to reduce leisure-time sedentary and/or alcohol consumption may contribute to a reduction in the proportion of adolescents engaging in sexual intercourse at a young age. The strengths and limitations of this study are the large, representative sample of adolescents from 19 countries. However, the cross-sectional design means causality or temporal associations could not be established. // CONCLUSIONS: In young adolescents, leisure-time sedentary behavior is positively associated with odds of having sexual intercourse in both boys and girls, in a dose-dependent manner. Alcohol consumption seems to be a key mediator of this relationship