Coordination of di- and triimine ligands at ruthenium(II) and ruthenium(III) centers: structural, electrochemical and radical scavenging studies

Herein, we explore the coordination of di- and triimine chelators at ruthenium(II) and ruthenium(III) centers. The reactions of 2,6-bis-((4- tetrahydropyranimino)methyl)pyridine (thppy), N1,N2-bis((3-chromone) methylene)benzene-1,2-diamine (chb), and tris-((1H-pyrrol-2-ylmethylene) ethane)amine (H3pym) with trans-[RuIICl2(PPh3)3] afforded the diamagnetic ruthenium(II) complex cis-[RuCl2(thppy)(PPh3)] (1) and the paramagnetic complexes [mer-Ru2(μ-chb)Cl6(PPh3)2] (2), and [Ru(pym)] (3), respectively. The complexes were characterized by IR, NMR, and UV–vis spectroscopy and molar conductivity measurements. The structures were confirmed by single crystal X-ray diffraction studies. The redox properties of the metal complexes were probed via cyclic- and squarewave voltammetry. Finally, the radical scavenging capabilities of the metal complexes towards the NO and 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) radicals were investigate

Student Misconceptions about Plants – A First Step in Building a Teaching Resource

Plants are ubiquitous and found in virtually every ecosystem on Earth, but their biology is often poorly understood, and inaccurate ideas about how plants grow and function abound. Many articles have been published documenting student misconceptions about photosynthesis and respiration, but there are substantially fewer on such topics as plant cell structure and growth; plant genetics, evolution, and classification; plant physiology (beyond energy relations); and plant ecology. The available studies of misconceptions held on those topics show that many are formed at a very young age and persist throughout all educational levels. Our goal is to begin building a central resource of plant biology misconceptions that addresses these underrepresented topics, and here we provide a table of published misconceptions organized by topic. For greater utility, we report the age group(s) in which the misconceptions were found and then map them to the ASPB – BSA Core Concepts and Learning Objectives in Plant Biology for Undergraduates, developed jointly by the American Society of Plant Biologists and the Botanical Society of America

Ruthenium complexes with Schiff base ligands containing benz(othiazole/imidazole) moieties: Structural, electron spin resonance and electrochemistry studies

Novel ruthenium(II/III) complexes of Schiff bases containing benzimidazole (bz) or benzothiazole (bs) moieties were isolated: the diamagnetic ruthenium complex, cis-[RuIICl2(bzpy)(PPh3)2] (1) was formed from the 1:1 M reaction between N-((pyridine-2-yl)methylene)-1H-benzimidazole (bzpy) and metal precursor, trans-[RuCl2(PPh3)3]. The same metal precursor, when reacted with the benzimidazole-derived Schiff bases [N-(2-hydroxybenzylidene)-benzothiazole (Hbsp) and N-(2-hydroxybenzylidene)-benzimidazole (Hbzp)], afforded the paramagnetic ruthenium(III) complexes [RuCl(bsp)2(PPh3)] (2) and trans-[RuCl(bzp)(PPh3)2] (3), respectively. These metal complexes were characterized via IR, mass and UV–Vis spectroscopy, elemental analysis, single crystal XRD analysis as well as conductivity measurements. Their redox properties were probed by voltammetry and accompanying UV–Vis spectroelectrochemistry experiments. Structural features of complex 1 were further investigated by multinuclear (1H and 31P) NMR spectroscopy

Thermal design and characterization of a modular integrated liquid cooled 1200 V-35 A SiC MOSFET bi-directional switch

The aim of this work is the thermal design of a modular direct liquid cooled package for 1200 V–35 A SiC power MOSFETs, in order to take full advantage of the high power density and high frequency performance of these devices, in the development of a modular integrated solution for power converters. An accurate electro-thermal fluid dynamic model is set up and validated by thermal characterization on a prototype; numerical models have been used to study the internal temperature distribution and to propose further optimization

CheXpert: A Large Chest Radiograph Dataset with Uncertainty Labels and Expert Comparison

Large, labeled datasets have driven deep learning methods to achieve expert-level performance on a variety of medical imaging tasks. We present CheXpert, a large dataset that contains 224,316 chest radiographs of 65,240 patients. We design a labeler to automatically detect the presence of 14 observations in radiology reports, capturing uncertainties inherent in radiograph interpretation. We investigate different approaches to using the uncertainty labels for training convolutional neural networks that output the probability of these observations given the available frontal and lateral radiographs. On a validation set of 200 chest radiographic studies which were manually annotated by 3 board-certified radiologists, we find that different uncertainty approaches are useful for different pathologies. We then evaluate our best model on a test set composed of 500 chest radiographic studies annotated by a consensus of 5 board-certified radiologists, and compare the performance of our model to that of 3 additional radiologists in the detection of 5 selected pathologies. On Cardiomegaly, Edema, and Pleural Effusion, the model ROC and PR curves lie above all 3 radiologist operating points. We release the dataset to the public as a standard benchmark to evaluate performance of chest radiograph interpretation models. The dataset is freely available at https://stanfordmlgroup.github.io/competitions/chexpert .Comment: Published in AAAI 201

Apparent treatment-resistant hypertension and risk for stroke, coronary heart disease, and all-cause mortality

Apparent treatment-resistant hypertension (aTRH) is defined as uncontrolled hypertension despite the use of three or more antihypertensive medication classes or controlled hypertension while treated with four or more antihypertensive medication classes. We evaluated the association of aTRH with incident stroke, coronary heart disease (CHD), and all-cause mortality. Participants from the population-based REasons for Geographic And Racial Differences in Stroke (REGARDS) Study treated for hypertension with aTRH (n = 2043) and without aTRH (n = 12,479) were included. aTRH was further categorized as controlled aTRH (≥4 medication classes and controlled hypertension) and uncontrolled aTRH (≥3 medication classes and uncontrolled hypertension). Over a median of 5.9, 4.4, and 6.0 years of follow-up, the multivariable adjusted hazard ratio for stroke, CHD, and all-cause mortality associated with aTRH versus no aTRH was 1.25 (0.94–1.65), 1.69 (1.27–2.24), and 1.29 (1.14–1.46), respectively. Compared with controlled aTRH, uncontrolled aTRH was associated with CHD (hazard ratio, 2.33; 95% confidence interval, 1.21–4.48), but not stroke or mortality. Comparing controlled aTRH with no aTRH, risk of stroke, CHD, and all-cause mortality was not elevated. aTRH was associated with an increased risk for coronary heart disease and all-cause mortality

Protocol: a systematic review of studies developing and/or evaluating search strategies to identify prognosis studies.

BACKGROUND Prognosis research is on the rise, its importance recognised because chronic health conditions and diseases are increasingly common and costly. Prognosis systematic reviews are needed to collate and synthesise these research findings, especially to help inform effective clinical decision-making and healthcare policy. A detailed, comprehensive search strategy is central to any systematic review. However, within prognosis research, this is challenging due to poor reporting and inconsistent use of available indexing terms in electronic databases. Whilst many published search filters exist for finding clinical trials, this is not the case for prognosis studies. This systematic review aims to identify and compare existing methodological filters developed and evaluated to identify prognosis studies of any of the three main types: overall prognosis, prognostic factors, and prognostic [risk prediction] models. METHODS Primary studies reporting the development and/or evaluation of methodological search filters to retrieve any type of prognosis study will be included in this systematic review. Multiple electronic bibliographic databases will be searched, grey literature will be sought from relevant organisations and websites, experts will be contacted, and citation tracking of key papers and reference list checking of all included papers will be undertaken. Titles will be screened by one person, and abstracts and full articles will be reviewed for inclusion independently by two reviewers. Data extraction and quality assessment will also be undertaken independently by two reviewers with disagreements resolved by discussion or by a third reviewer if necessary. Filters' characteristics and performance metrics reported in the included studies will be extracted and tabulated. To enable comparisons, filters will be grouped according to database, platform, type of prognosis study, and type of filter for which it was intended. DISCUSSION This systematic review will identify all existing validated prognosis search filters and synthesise evidence about their applicability and performance. These findings will identify if current filters provide a proficient means of searching electronic bibliographic databases or if further prognosis filters are needed and can feasibly be developed for systematic searches of prognosis studies

Genome- and CD4\u3csup\u3e+\u3c/sup\u3e T-Cell Methylome-Wide Association Study of Circulating Trimethylamine-N-Oxide in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN)

Background: Trimethylamine-N-oxide (TMAO), an atherogenic metabolite species, has emerged as a possible new risk factor for cardiovascular disease. Animal studies have shown that circulating TMAO levels are regulated by genetic and environmental factors. However, large-scale human studies have failed to replicate the observed genetic associations, and epigenetic factors such as DNA methylation have never been examined in relation to TMAO levels. Methods and results: We used data from the family-based Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) to investigate the heritable determinants of plasma TMAO in humans. TMAO was not associated with other plasma markers of cardiovascular disease, e.g. lipids or inflammatory cytokines. We first estimated TMAO heritability at 27%, indicating a moderate genetic influence. We used 1000 Genomes imputed data (n = 626) to estimate genome-wide associations with TMAO levels, adjusting for age, sex, family relationships, and study site. The genome-wide study yielded one significant hit at the genome-wide level, located in an intergenic region on chromosome 4. We subsequently quantified epigenome-wide DNA methylation using the Illumina Infinium array on CD4þ Tcells. We tested for association of methylation loci with circulating TMAO (n = 847), adjusting for age, sex, family relationships, and study site as the genome-wide study plus principal components capturing CD4þ T-cell purity. Upon adjusting for multiple testing, none of the epigenetic findings were statistically significant. Conclusions: Our findings contribute to the growing body of evidence suggesting that neither genetic nor epigenetic factors play a critical role in establishing circulating TMAO levels in humans