Enhanced electron transfer in composite films of reduced graphene oxide and poly(N-methylaniline)

Poly(N-methylaniline) (FNMA) has been electropolymerized for the first time from a graphene oxide (GO) dispersion containing 1.0 M HClO4. Both GO and perchlorate were incorporated in the PNMA matrix during the electropolymerization resulting in the formation of a mixed composite material of PNMA-ClO4 and PNMA-GO. Under the acidic polymerization conditions, the carboxylic groups of GO are undissociated and GO is therefore mostly mechanically entrapped in the PNMA matrix while perchlorate functions as the primary charge compensating ion. Electrochemical reduction at -0.85 V improved the election transfer of the composite film due to reduction of GO in the PNMA matrix. (C) 2013 Elsevier Ltd. All rights reserved

Medical students' biomedical and clinical knowledge: Combining longitudinal design, eye tracking and comparison with residents' performance

This study combines longitudinal and individual process-level analyses to investigate medical students' biomedical knowledge and how they generate a diagnosis for a patient case text. The diagnostic processes were investigated using the eye-tracking method, and students' processes were compared with those of residents. The results showed that students differed in their diagnostic performance in the beginning of the clinical phase. Of the students who had biomedical misconceptions in the preclinical phase, 69% ended up with an incorrect diagnosis, while 60% of students with accurate biomedical knowledge made a correct diagnosis. The processing of a patient case text was faster among better achieving students and residents. Furthermore, residents' illness-script activation could be seen from their eye-movement data as a relatively longer reading time regarding the sentence that concerned the enabling condition of the case. Based on the results of the study, pedagogical suggestions are discussed. (C) 2017 Elsevier Ltd. All rights reserved

Diversity of respiratory parameters and metabolic adaptation to low oxygen tension in mesenchymal stromal cells

Objective Cell metabolism has been shown to play an active role in regulation of stemness and fate decision. In order to identify favorable culture conditions for mesenchymal stromal cells (MSCs) prior to transplantation, this study aimed to characterize the metabolic function of MSCs from different developmental stages in response to different oxygen tension during expansion. Materials and methods We cultured human fetal cardiac MSCs and human adult bone-marrow MSCs for a week under hypoxia (3% O2) and normoxia (20% O2). We performed mitochondrial characterization and assessed oxygen consumption- and extracellular acidification-rates (OCR and ECAR) in addition to oxygen-sensitive respiration and mitochondrial complex activities, using both the Seahorse and Oroboros systems. Results Adult and fetal MSCs displayed similar basal respiration and mitochondrial amount, however fetal MSCs had lower spare respiratory capacity and apparent coupling efficiency. Fetal MSCs expanded in either hypoxia or normoxia demonstrated similar acidification rates, while adult MSCs downregulated their aerobic glycolysis in normoxia. Acute decrease in oxygen tension caused a higher respiratory inhibition in adult compared to fetal MSCs. In both sources of MSCs, minor changes in complex activities in normoxic and hypoxic cultures were found. Conclusions In contrast to adult MSCs, fetal MSCs displayed similar respiration and aerobic glycolysis at different O2 culture concentrations during expansion. Adult MSCs adjusted their respiration to glycolytic activities, depending on the culture conditions thus displaying a more mature metabolic function. These findings are relevant for establishing optimal in vitro culturing conditions, with the aim to maximize engraftment and therapeutic outcome.CC BY-NC-ND 4.0Corresponding author: Department of Surgical Sciences, Uppsala University, 751 85, Uppsala, Sweden. E-mail address: [email protected] (K.-H. Grinnemo).Available online 3 February 2022, Version of Record 5 February 2022The project was funded by Karolinska Institute-Mayo Clinic Collaborative Grant 2013; The Swedish Research Council young investigator: 2013–3590; Stockholm county; The Swedish Research Council; The Family Erling-Persson Foundation; ERC-2018-AdG (834860 EYELETS); Uppsala county; Uppsala County Association against Heart and Lung Diseases; and Higher Education of the Russian Federation (agreement no. 075-15-2020-899).</p

Soluble CD93 Is Involved in Metabolic Dysregulation but Does Not Influence Carotid Intima-Media Thickness

Type 2 diabetes and cardiovascular disease are complex disorders involving metabolic and inflammatory mechanisms. Here we investigated whether sCD93, a group XIV c-type lectin of the endosialin family, plays a role in metabolic dysregulation or carotid intima-media thickness (IMT). Although no association was observed between sCD93 and IMT, sCD93 levels were significantly lower in subjects with type 2 diabetes (n = 901, mean ± SD 156.6 ± 40.0 ng/mL) compared with subjects without diabetes (n = 2,470, 164.1 ± 44.8 ng/mL, P < 0.0001). Genetic variants associated with diabetes risk (DIAGRAM Consortium) did not influence sCD93 levels (individually or combined in a single nucleotide polymorphism score). In a prospective cohort, lower sCD93 levels preceded the development of diabetes. Consistent with this, a cd93-deficient mouse model (in addition to apoe deficiency) demonstrated no difference in atherosclerotic lesion development compared with apoe(-/-) cd93-sufficient littermates. However, cd93-deficient mice showed impaired glucose clearance and insulin sensitivity (compared with littermate controls) after eating a high-fat diet. The expression of cd93 was observed in pancreatic islets, and leaky vessels were apparent in cd93-deficient pancreases. We further demonstrated that stress-induced release of sCD93 is impaired by hyperglycemia. Therefore, we propose CD93 as an important component in glucometabolic regulation

A Genome-Wide Association Study of Diabetic Kidney Disease in Subjects With Type 2 Diabetes

dentification of sequence variants robustly associated with predisposition to diabetic kidney disease (DKD) has the potential to provide insights into the pathophysiological mechanisms responsible. We conducted a genome-wide association study (GWAS) of DKD in type 2 diabetes (T2D) using eight complementary dichotomous and quantitative DKD phenotypes: the principal dichotomous analysis involved 5,717 T2D subjects, 3,345 with DKD. Promising association signals were evaluated in up to 26,827 subjects with T2D (12,710 with DKD). A combined T1D+T2D GWAS was performed using complementary data available for subjects with T1D, which, with replication samples, involved up to 40,340 subjects with diabetes (18,582 with DKD). Analysis of specific DKD phenotypes identified a novel signal near GABRR1 (rs9942471, P = 4.5 x 10(-8)) associated with microalbuminuria in European T2D case subjects. However, no replication of this signal was observed in Asian subjects with T2D or in the equivalent T1D analysis. There was only limited support, in this substantially enlarged analysis, for association at previously reported DKD signals, except for those at UMOD and PRKAG2, both associated with estimated glomerular filtration rate. We conclude that, despite challenges in addressing phenotypic heterogeneity, access to increased sample sizes will continue to provide more robust inference regarding risk variant discovery for DKD.Peer reviewe

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms