Roles of Pyruvate, NADH, and Mitochondrial Complex I in Redox Balance and Imbalance in β

Pancreatic β cells not only use glucose as an energy source, but also sense blood glucose levels for insulin secretion. While pyruvate and NADH metabolic pathways are known to be involved in regulating insulin secretion in response to glucose stimulation, the roles of many other components along the metabolic pathways remain poorly understood. Such is the case for mitochondrial complex I (NADH/ubiquinone oxidoreductase). It is known that normal complex I function is absolutely required for episodic insulin secretion after a meal, but the role of complex I in β cells in the diabetic pancreas remains to be investigated. In this paper, we review the roles of pyruvate, NADH, and complex I in insulin secretion and hypothesize that complex I plays a crucial role in the pathogenesis of β cell dysfunction in the diabetic pancreas. This hypothesis is based on the establishment that chronic hyperglycemia overloads complex I with NADH leading to enhanced complex I production of reactive oxygen species. As nearly all metabolic pathways are impaired in diabetes, understanding how complex I in the β cells copes with elevated levels of NADH in the diabetic pancreas may provide potential therapeutic strategies for diabetes

Synthesis and optical properties of composite films from P3HT and sandwich-like Ag-C-Ag nanoparticles

This document is the Accepted Manuscript of the following article: Lingpeng Yan, Yamin Hao, Xiaoting Feng, Yongzhen Yang, Xuguang Liu, Yongkang Chen, and Bingshe Xu, ‘Synthesis and optical properties of composite films from P3HT and sandwich-like Ag–C–Ag nanoparticles’, RSC Advances, Vol. 5(97): 79860-79867, 2015, DOI: https://doi.org/10.1039/C5RA16854F. Content in the UH Research Archive is made available for personal research, educational, and non-commercial purposes only. Unless otherwise stated, all content is protected by copyright, and in the absence of an open license, permissions for further re-use should be sought from the publisher, the author, or other copyright holder.Sandwich-like Ag-C-Ag nanoparticles (Ag-C-Ag NPs) were synthesized under mild hydrothermal conditions in a one-step method. With this approach, Ag was not only encapsulated in the centre of an individual carbon nanosphere, but was also uniformly dispersed within the carbon matrix up to the sphere's shell. Then, poly(3-hexylthiophene):Ag-C-Ag NPs (P3HT:Ag-C-Ag NPs) composite films were prepared by a spin coating method with a chlorobenzene solution of Ag-C-Ag NPs and P3HT. Both morphology and microstructure of Ag-C-Ag NPs were investigated by field emission scanning electron microscopy and high resolution transmission electron microscopy. The possible formation mechanism was proposed. The results have indicated that the Ag-C-Ag NPs present many functional groups and their energy levels match with those of P3HT. It has been observed that an introduction of Ag-C-Ag NPs to P3HT can induce broad and high-absorbing spectra as well as great photoluminescence quenching of P3HT. It is evident that sandwich-like Ag-C-Ag NPs have a great potential to be a new acceptor material in photovoltaic devices.Peer reviewe

Quasiparticle Scattering Interference in Superconducting Iron-pnictides

Using both two orbital and five orbital models, we investigate the quasiparticle interference (QPI) patterns in the superconducting (SC) state of iron-based superconductors. We compare the results for nonmagnetic and magnetic impurities in sign-changed s-wave $\cos(k_x)\cdot\cos(k_y)$ and sign-unchanged $|\cos(k_x)\cdot\cos(k_y)|$ SC states. While the patterns strongly depend on the chosen band structures, the sensitivity of peaks around $(\pm\pi,0)$ and $(0,\pm\pi)$ wavevectors on magnetic or non-magnetic impurity, and sign change or sign unchanged SC orders is common in two models. Our results strongly suggest that QPI may provide direct information of band structures and evidence of the pairing symmetry in the SC states.Comment: 12 pages, 16 figure

Fertilization and Cytogenetic Examination of Interspecific Reciprocal Hybridization between the Scallops, Chlamys farreri and Mimachlamys nobilis

Crossbreeding is a powerful tool for improving productivity and profitability in aquaculture. We conducted a pilot study of an artificial cross between two important cultivated scallops in China, Chlamys farreri and Mimachlamys nobilis, to test the feasibility of interspecific hybridization. Reciprocal hybridization experiments were performed using a single-pair mating strategy (M. nobilis ♀ × C. farreri ♂ and C. farreri ♀ × M. nobilis ♂). The fertilization of each pair was tracked using fluorescence staining of the gametes, and the chromosomes of the F1 hybrid larvae were examined via conventional karyotyping and genomic in situ hybridization (GISH). We observed moderate fertilization success in both interspecific crosses, although the overall fertilization was generally less rapid than that of intraspecific crosses. Conventional karyotyping showed that 70.4% of the viable F1 larvae in M. nobilis ♀ × C. farreri ♂ and 55.4% in C. farreri ♀ × M. nobilis ♂ comprised hybrid karyotypes (2n = 35 = 6m+5sm+11st+13t), and the results were further confirmed by GISH. Interestingly, we detected a few F1 from the M. nobilis ♀ × C. farreri ♂ cross that appeared to have developed gynogenetically. In addition, chromosome fragmentations, aneuploids and allopolyploids were observed in some F1 individuals. Our study presents evidence that the artificial cross between M. nobilis and C. farreri is experimentally possible. Further investigations of the potential heterosis of the viable F1 offspring at various developmental stages should be conducted to obtain a comprehensive evaluation of the feasibility of crossbreeding between these two scallop species

Bone Loss Prevention of Bisphosphonates in Patients with Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

Objective. The purpose of this study was to evaluate the effect of bisphosphonates in improving bone mineral density (BMD) and decreasing the occurrence rate of fractures and adverse events in patients with inflammatory bowel disease (IBD). Methods. Randomized controlled trials (RCTs) which use bisphosphonates in IBD patients were identified in PubMed, MEDLINE database, EMBASE database, Web of Knowledge, and the Cochrane Databases between 1990 and June 2016. People received bisphosphonate or placebos with a follow-up of at least one year were also considered. STATA 12.0 software was used for the meta-analysis. Results. Eleven randomized clinical trials were included in the meta-analysis. The data indicated that the percentage change in the increased BMD in the bisphosphonates groups was superior to that of the control groups at the lumbar spine and total hip. At the femoral neck, there was no significant difference between the two groups. The incidence of new fractures during follow-up showed significant reduction. The adverse event analysis revealed no significant difference between the two groups. Conclusion. Our results demonstrate that bisphosphonates therapy has an effect on bone loss in patients with IBD but show no evident efficiency at increasing the incidence of adverse events

THGNN: Temporal Heterophilic Graph Neural Network for Event-based Graph

The present disclosure proposes techniques (e.g., a method and a system) for generating temporal heterophilic graph neural network (THGNN) for event-based graphs. All existing (temporal) GNNs typically follow temporal homophily assumption, while the real-world graphs are largely heterophilic. To solve this problem, the proposed disclosure first defines the graph heterophily based on edge heterophily and then develops a novel method/technique to automatically detect the homophily/heterophily weight of graph nodes that should be regarded as the focal node’s homophilic/heterophilic neighbours. Finally, a neighbourhood sampling based GNN is adopted. In this manner, the proposed disclosure defines heterophily for temporal graphs and proposes a novel adaptive method to select right neighbourhood for graph aggregation

TinyKG: Memory-Efficient Training Framework for Knowledge Graph Neural Recommender Systems

There has been an explosion of interest in designing various Knowledge Graph Neural Networks (KGNNs), which achieve state-of-the-art performance and provide great explainability for recommendation. The promising performance is mainly resulting from their capability of capturing high-order proximity messages over the knowledge graphs. However, training KGNNs at scale is challenging due to the high memory usage. In the forward pass, the automatic differentiation engines (\textsl{e.g.}, TensorFlow/PyTorch) generally need to cache all intermediate activation maps in order to compute gradients in the backward pass, which leads to a large GPU memory footprint. Existing work solves this problem by utilizing multi-GPU distributed frameworks. Nonetheless, this poses a practical challenge when seeking to deploy KGNNs in memory-constrained environments, especially for industry-scale graphs. Here we present TinyKG, a memory-efficient GPU-based training framework for KGNNs for the tasks of recommendation. Specifically, TinyKG uses exact activations in the forward pass while storing a quantized version of activations in the GPU buffers. During the backward pass, these low-precision activations are dequantized back to full-precision tensors, in order to compute gradients. To reduce the quantization errors, TinyKG applies a simple yet effective quantization algorithm to compress the activations, which ensures unbiasedness with low variance. As such, the training memory footprint of KGNNs is largely reduced with negligible accuracy loss. To evaluate the performance of our TinyKG, we conduct comprehensive experiments on real-world datasets. We found that our TinyKG with INT2 quantization aggressively reduces the memory footprint of activation maps with $7 \times$, only with $2\%$ loss in accuracy, allowing us to deploy KGNNs on memory-constrained devices

Impact of central venous pressure on the mortality of patients with sepsis-related acute kidney injury: a propensity score-matched analysis based on the MIMIC IV database

Central venous pressure (CVP); Database; MortalityPressió venosa central (PVC); Base de dades; MortalitatPresión venosa central (PVC); Base de datos; MortalidadBackground: Sepsis has long been a life-threatening organ dysfunction. Sepsis associated acute kidney injury (SA-AKI) is an important complication of sepsis, as an important hemodynamic index, the impact of central venous pressure (CVP) on sepsis patients needs to be explored. Thus this study aimed to investigate the relationship between CVP and the mortality of SA-AKI. Methods: Clinical data of adult patients with sepsis-related acute kidney injury, defined as met both the Sepsis 3.0 criteria and the Kidney Disease Improving Global Outcomes Clinical Practice Guideline (KDIGO) criteria, were obtained from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database. The included cohort was divided into a high CVP and a low CVP group were determined based on the cuf-off value from receiver operating characteristic curve, with propensity score-matched analysis of the 28-day mortality for both groups and sensitivity analysis using inverse the probability-weighting model, multifactorial regression, and doubly robust estimation, patients acquired chronic coronary syndrome (CCS) and diabetes were also taken into consideration. Results: Of 1,377 patients with sepsis-related acute kidney injury, low CVP group (<13 mmHg) was 67.4% (n=928) and high CVP group (≥13 mmHg) was 32.6% (n=449). The two groups were matched 1:1 by propensity score to obtain a matched cohort (n=288). The mortality rates in the low versus high CVP group (19.4% vs. 34.7%) were statistically difference (odds ratio OR: 0.454; 95% confidence interval 0.263, 0.771). Moreover, the bistable analysis of logistic regression of the matched cohort (OR: 0.434; 95% CI: 0.244, 0.757), propensity score inverse probability weighting (IPW) (OR: 0.547; 95% CI: 0.454, 0.658), and multifactorial logistic regression (OR: 0.352; 95% CI: 0.127, 0.932) all yielded the same results. Conclusions: In patients with sepsis-related acute kidney injury, a lower CVP level (<13 mmHg) is an independent variable associated with decreased mortality. The threshold of CVP needs to be controlled in clinical work to improve the prognosis of patients with SA-AKI