bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synergistically Tuning Water and Hydrogen Binding Abilities Over Co4N by Cr Doping for Exceptional Alkaline Hydrogen Evolution Electrocatalysis
Authors: Yao Na , Li Peng , Zhou Zirui , Zhao Yuanmeng , Cheng Gongzhen , Chen Shengli , Luo Wei 
Published: September 2019

AbstractSearching for highly efficient and cost‐effective electrocatalysts toward the hydrogen evolution reaction (HER) in alkaline electrolyte is highly desirable for the development of alkaline water splitting, but still remains a significant challenge. Herein, the rational design of Cr‐doped Co4N nanorod arrays grown on carbon cloth (Cr–Co4N/CC) that can efficiently catalyze the HER in alkaline media is reported. It displays outstanding performance, with the exceptionally small overpotential of 21 mV to obtain the current density of 10 mA cm−2 and good stability in 1.0 m KOH, which is even better than the commercial Pt/C electrocatalyst, and much lower than most of the reported transition metal nitride‐based and other non‐noble metal‐based electrocatalysts toward the alkaline HER. Density functional theory (DFT) calculations and experimental results reveal that the Cr atoms not only act as oxophilic sites for boosting water adsorption and dissociation, but also modulate the electronic structure of Co4N to endow optimized hydrogen binding abilities on Co atoms, thereby leading to accelerating both the alkaline Volmer and Heyrovsky reaction kinetics. In addition, this strategy can be extended to other metals (such as Mo, Mn, and Fe) doped Co4N electrocatalysts, thus may open up a new avenue for the rational design of highly efficient transition metal nitride‐based HER catalysts and beyond.
Evaluation of Gender Differences in Ultrasound Milestone Evaluations During Emergency Medicine Residency Training: A Multicenter Study
Authors: Acuña Josie , Stolz Uwe , Stolz Lori A. , Situ‐LaCasse Elaine H. , Bell Gregory , Berkeley Ross P. , Boyd Jeremy S. , Castle David , Carmody Kristin , Fong Tiffany , Grewal Ekjot , Jones Robert , Hilberts SueLin , Kanter Carolyn , Kelley Kenneth , Leetch Stephen J. , Pazderka Philip , Shaver Erica , Stowell Jeffrey R. , Josephson Elaine B. , Theodoro Daniel , Adhikari Srikar 
Published: September 2019

AbstractObjectivesPrior literature has demonstrated incongruities among faculty evaluation of male and female residents’ procedural competency during residency training. There are no known studies investigating gender differences in the assessment of procedural skills among emergency medicine (EM) residents, such as those required by ultrasound. The objective of this study was to determine if there are significant gender differences in ultrasound milestone evaluations during EM residency training.MethodsWe used a stratified, random cluster sample of Accreditation Council for Graduate Medical Education (ACGME) EM residency programs to conduct a longitudinal, retrospective cohort analysis of resident ultrasound milestone evaluation data. Milestone evaluation data were collected from a total of 16 ACGME‐accredited EM residency programs representing a 4‐year period. We stratified milestone data by resident gender, date of evaluation, resident postgraduate year, and cohort (residents with the same starting date).ResultsA total of 2,554 ultrasound milestone evaluations were collected from 1,187 EM residents (750 men [62.8%] and 444 women [37.1%]) by 104 faculty members during the study period. There was no significant overall difference in mean milestone score between female and male residents [mean difference = 0.01 (95% confidence interval {CI} = −0.04 to 0.05)]. There were no significant differences between female and male residents’ mean milestone scores at the first (baseline) PGY1 evaluation (mean difference = −0.04 [95% CI = −0.09 to 0.003)] or at the final evaluation during PGY3 (mean difference = 0.02 [95% CI = −0.03 to 0.06)].ConclusionsDespite prior studies suggesting gender bias in the evaluation of procedural competency during residency training, our study indicates that there were no significant gender‐related differences in the ultrasound milestone evaluations among EM residents within training programs throughout the United States.
From maternal tending to adolescent befriending: The adolescent transition of social support
Authors: Rodrigues Michelle A. , Sanford Summer R. , Rogers Mary P. , Lee Katharine M.N. , Wilson Meredith A. , Amos Jennifer , Hunter Carla D. , Clancy Kathryn B.H. 
Published: September 2019

AbstractAttachment theory holds that parental relationships have lifelong effects on offspring social lives. The tend‐and‐befriend hypothesis posits that female friendships among humans evolved as part of a primate‐wide coping mechanism to mediate stress by relying on social support. Here we bridge developmental and evolutionary frameworks to examine adolescent girls’ perception of their reliance on female friendship for social support, how perceptions of parental relationships affect peer relationships, and the extent to which parent and peer relationships buffer depressive symptoms. We predict perceived maternal relationship quality will be positively associated with close female friendships, and maternal relationships, paternal relationships, and female friendship will buffer depressive symptoms. Participants were adolescent girls from a summer science camp (N = 95). Participants filled out demographic information, social network surveys, the Parent‐Adolescent Communication Scale, and the Center for Epidemiology Depression Scale. Data was analyzed with Pearson's correlations, t tests, and path analysis. Adolescent girls with few female friends, compared with girls who had more than two very close female friends, experienced more depressive symptoms (t = 3.382, p = .001, D = 0.784). Adolescent girls with few female friends experienced more depressive symptoms compared to girls with two or more very close female friends (t = 3.382, p = .001, D = 0.784). Stronger maternal and paternal relationships were associated with having more female friends (maternal: t = −3.213, p = .003, D = 0.837; paternal: t = −2.432; p = .017). In the path analysis model, only maternal relationship quality significantly predicted female friendship category (β = .33, CR = 2.770, p < .006). Furthermore, participants with two or more very close female friends and higher paternal relationship quality had significantly fewer depressive symptoms (friends; β = −.19, CR = −2.112, p = .035; paternal: β = −.33, CR = −3.220, p < .001), and older participants had more depressive symptoms (β = .17, CR = −1.931, p = .036). These results provide additional support for the tend‐and‐befriend hypothesis, suggesting that maternal tending sets the stage for close female friendships.
A rare case of right‐sided infective endocarditis caused by group B Streptococcus complicated with septic knee arthritis and subcutaneous abscess in the lower extremity
Authors: Takeda Shinsuke , Tanaka Yoshihiro , Takeichi Yosuke , Hirata Hitoshi , Tabuchi Akihiko 
Published: September 2019

BackgroundSeveral reports have assessed group B Streptococcus (GBS) infections in non‐pregnant cohorts, especially in immunocompromised hosts and patients with severe disease, including diabetes mellitus.Case presentationWe report a rare case of large GBS‐associated tricuspid valve infective endocarditis (IE) complicated with septic knee arthritis and s.c. abscess formation in the lower extremity of a non‐i.v. drug user. After confirming the absence of vegetation on transthoracic echocardiography (TTE) at admission, the lower extremity was irrigated, and antibiotic therapy was initiated. One week later, the causes of persistent fever were reinvestigated. The TTE detected a large mass around the tricuspid valve. The cultured GBS was penicillin sensitive. The vegetation completely disappeared without surgery within 4 weeks.ConclusionWhen patients with untreated diabetes mellitus have persistent fever and s.c. abscess or septic arthritis, IE is a possible differential diagnosis. Repetitive evaluation by TTE is warranted to avoid this fatal complication.
Photochemical Asymmetric Nickel‐Catalyzed Acyl Cross‐Coupling
Authors: Gandolfo Eugenio , Tang Xinjun , Raha Roy Sudipta , Melchiorre Paolo 
Published: September 2019

AbstractPhotochemical enantioselective nickel‐catalyzed cross‐coupling reactions are difficult to implement. We report a visible‐light‐mediated strategy that successfully couples symmetrical anhydrides and 4‐alkyl dihydropyridines (DHPs) to afford enantioenriched α‐substituted ketones under mild conditions. The chemistry does not require exogenous photocatalysts. It is triggered by the direct excitation of DHPs, which act as a radical source and as a reductant, facilitating the turnover of the chiral catalytic nickel complex.
Theranostic Nanoplatform with Hydrogen Sulfide Activatable NIR Responsiveness for Imaging‐Guided On‐Demand Drug Release
Authors: Shi Ben , Ren Ning , Gu Luyan , Xu Ge , Wang Rongchen , Zhu Tianli , Zhu Ying , Fan Chunhai , Zhao Chunchang , Tian He 
Published: September 2019

AbstractNIR light responsive nanoplatforms hold great promise for on‐demand drug release in precision cancer medicine. However, currently available systems utilize “always‐on” photothermal transducers that lack target specificity, and thus inaccurately differentiate tumors from normal tissues. Developed here is a theranostic nanoplatform featuring H2S‐mediated in situ production of NIR photothermal agents for imaging‐guided and photocontrolled drug release. The system targets H2S‐rich cancers. This nanoplatform shows H2S‐activatable NIR‐II emission and NIR light controllable release of the drug Camptothecin‐11. Upon administering the system to HCT116 tumor‐bearing mice, the tumor is greatly suppressed with minimal side effects, arising from the synergy of the cancer‐specific and NIR light activated therapy. This theranostic nanoplatform thus sheds light on precision medicine with guidance through NIR‐II imaging.
Novel N‐(1‐thia‐4‐azaspiro[4.5]decan‐4‐yl)carboxamide derivatives as potent and selective influenza virus fusion inhibitors
Authors: Göktaş Füsun , Özbil Mehmet , Cesur Nesrin , Vanderlinden Evelien , Naesens Lieve , Cesur Zafer 
Published: September 2019

AbstractHemagglutinin is the surface protein of the influenza virus that mediates both binding and penetration of the virus into host cells. We here report on the synthesis and structure–activity relationship of some novel N‐(1‐thia‐4‐azaspiro[4.5]decan‐4‐yl)‐carboxamide compounds carrying the 5‐chloro‐2‐methoxybenzamide structure, designed as influenza virus fusion inhibitors. The carboxamides (1a–h, 2a–h) have a similar backbone structure as the fusion inhibitors that we reported on previously. Compounds 2b and 2d displayed inhibitory activity against influenza A/H3N2 virus replication (average antiviral EC50: 2.1 µM for 2b and 3.4 µM for 2d). Data obtained in the hemolysis inhibition assay supported that these compounds act as inhibitors of the influenza virus hemagglutinin‐mediated fusion process.
Impact of Cumulative Inflammation, Cardiac Risk Factors, and Medication Exposure on Coronary Atherosclerosis Progression in Rheumatoid Arthritis
Authors: Karpouzas George A. , Ormseth Sarah R. , Hernandez Elizabeth , Budoff Matthew J. 
Published: September 2019

ObjectiveTo explore incidence and progression of coronary atherosclerosis and identify determinants in patients with rheumatoid arthritis (RA). We specifically evaluated the impact of inflammation, cardiac risk factors, duration of medication exposure, and their interactions on coronary plaque progression.MethodsOne hundred one participants with baseline coronary computed tomography angiography findings underwent follow‐up assessment a mean ± SD of 83 ± 3.6 months after baseline. Plaque burden was reported as the segment involvement score (describing the number of coronary segments with plaque) and the segment stenosis score (characterizing the cumulative plaque stenosis over all evaluable segments). Plaque composition was classified as noncalcified, mixed, or calcified. Coronary artery calcium (CAC) was quantified using the Agatston method.ResultsTotal plaque increased in 48% of patients, and progression was predicted by older age, higher cumulative inflammation, and total prednisone dose (P < 0.05). CAC progressors were older, more obese, hypertensive, and had higher cumulative inflammation compared to nonprogressors (P < 0.05). Longer exposure to biologics was associated with lower likelihood of noncalcified plaque progression, lesion remodeling, and constrained CAC change in patients without baseline calcification, independent of inflammation, prednisone dose, or statin exposure (all P < 0.05). Longer statin treatment further restricted noncalcified plaque progression and attenuated the effect of inflammation on increased plaque and CAC (P < 0.05). Stringent systolic blood pressure (BP) control further weakened the effect of inflammation on total plaque progression.ConclusionInflammation was a consistent and independent predictor of coronary atherosclerosis progression in RA. It should therefore be specifically targeted toward mitigating cardiovascular risk. Biologic disease‐modifying antirheumatic drugs, statins, and BP control may further constrain plaque progression directly or indirectly.
Lutein upregulates the PGC‐1α, NRF1, and TFAM expression by AMPK activation and downregulates ROS to maintain mtDNA integrity and mitochondrial biogenesis in hyperglycemic ARPE‐19 cells and rat retina
Authors: Nanjaiah Hemalatha , Vallikannan Baskaran 
Published: September 2019

AbstractHyperglycemia (HG) affects cellular organelle including mitochondrion in retina that diminishes mitochondrial biogenesis by downregulation of nuclear transcription factors peroxisome proliferator‐activated receptor‐γ coactivator‐1 (PGC‐1α) and mitochondrial transcription factor A (TFAM). Mitochondrial dysfunction has been linked to diabetic retinopathy (DR). Carotenoids reported to modulate mitochondrial biogenesis in HG. Aim of the study was to explore the role of lutein, oxidized lutein (purified upon UV oxidation of lutein) and drug metformin, on mitochondrial biogenesis in HG‐induced ARPE‐19 cells and rat retina. Results showed higher uptake of lutein and oxidized lutein in ARPE‐19 cells and rat retina of HG group than the control groups. Further, lutein and oxidized lutein augmented the AMPK phosphorylation and activation of mitochondrion signaling molecule TFAM (protein expression) and mRNA expression of PGC‐1α, TFAM, and nuclear respiratory factor 1 (responsible for mitochondria biogenesis) along with lowered reactive oxygen species in HG compared with control and metformin groups. Higher mRNA expression of nicotinamide adenine dinucleotide dehydrogenase subunits mt‐ND1, mt‐ND4, mt‐ND6, and cytochrome C that aid maintenance of mtDNA integrity was also evidenced. To conclude, lutein and oxidized lutein found to upsurge mitochondrial biogenesis in ARPE‐19 cells and rat retina under HG, which may be due to upregulation of AMPK phosphorylation. Finally, lutein and oxidized lutein may provide a therapeutic basis to ameliorate HG‐induced DR.
Characterization of a Dehydratase and Methyltransferase in the Biosynthesis of Ribosomally Synthesized and Post‐translationally Modified Peptides in Lachnospiraceae
Authors: Huo Liujie , Zhao Xiling , Acedo Jeella Z. , Estrada Paola , Nair Satish K. , van der Donk Wilfred A. 
Published: September 2019

AbstractAs a result of the exponential increase in genomic data, discovery of novel ribosomally synthesized and post‐translationally modified peptide natural products (RiPPs) has progressed rapidly in the past decade. The lanthipeptides are a major subset of RiPPs. Through genome mining we identified a novel lanthipeptide biosynthetic gene cluster (lah) from Lachnospiraceae bacterium C6A11, an anaerobic bacterium that is a member of the human microbiota and which is implicated in the development of host disease states such as type 2 diabetes and resistance to Clostridium difficile colonization. The lah cluster encodes at least seven putative precursor peptides and multiple post‐translational modification (PTM) enzymes. Two unusual class II lanthipeptide synthetases LahM1/M2 and a substrate‐tolerant S‐adenosyl‐l‐methionine (SAM)‐dependent methyltransferase LahSB are biochemically characterized in this study. We also present the crystal structure of LahSB in complex with product S‐adenosylhomocysteine. This study sets the stage for further exploration of the final products of the lah pathway as well as their potential physiological functions in human/animal gut microbiota.
Unveiling Two Consecutive Hydroxylations: Mechanisms of Aromatic Hydroxylations Catalyzed by Flavin‐Dependent Monooxygenases for the Biosynthesis of Actinorhodin and Related Antibiotics
Authors: Hashimoto Makoto , Taguchi Takaaki , Ishikawa Kazuki , Mori Ryuichiro , Hotta Akari , Watari Susumu , Katakawa Kazuaki , Kumamoto Takuya , Okamoto Susumu , Ichinose Koji 
Published: September 2019

AbstractFlavin‐dependent monooxygenases are ubiquitous in living systems and are classified into single‐ or two‐component systems. Actinorhodin, produced by Streptomyces coelicolor, is a representative polycyclic polyketide that is hydroxylated through the action of the two‐component ActVA‐5/ActVB hydroxylase system. These homologous systems are widely distributed in bacteria, but their reaction mechanisms remain unclear. This in vitro investigation has provided chemical proof of two consecutive hydroxylations via hydroxynaphthalene intermediates involved in actinorhodin biosynthesis. The ActVA‐5 oxygenase component catalyzed a stepwise dihydroxylation of the substrate, whereas the ActVB flavin reductase not only supplied a reduced cofactor, but also regulated the quinone–hydroquinone interconversion of an intermediate. Our study provides clues for understanding the general biosynthetic mechanisms of highly functionalized aromatic natural products with structural diversity.
Synthesis of the Urchin‐Like NiS@NiCo2S4 Composites on Nickel Foam for High‐Performance Supercapacitors
Authors: Yang Ping , Feng Lina , Hu Jun , Ling Wenqin , Wang Shaohua , Shi Jianjun , Yang Zhangfu , Wang Fengwu 
Published: September 2019

AbstractA simple hydrothermal treatment process was used to prepare urchin‐like NiS@NiCo2S4 composites on Ni foam, which were then employed as binder‐free and conductive‐agent‐free electrodes for pseudocapacitors. The as‐synthesized composites have significant capacitive performance because of the novel porous structure. A specific capacitance up to 14.32 F cm−2 was obtained at a current density of 5 mA cm−2, which was far higher than that of pristine NiCo2S4 nanotube arrays (about 8.4 F cm−2). More importantly, Ni@NiS@NiCo2S4 and activated carbon (AC) were assembled as the positive and negative electrode, respectively, in an asymmetric supercapacitor, which possesses prominent performance. In addition to 78.7 % capacitance retention when cycling at 50 mA cm−2 for 5000 cycles, the as‐fabricated Ni@NiS@NiCo2S4//AC device exhibits a high energy density of 38.96 Wh kg−1 and power density of 339.62 W kg−1 at a current density of 10 mA cm−2.
Amphoteric Membranes Based on Sulfonated Polyether Ether Ketone and Imidazolium‐Functionalized Polyphenylene Oxide for Vanadium Redox Flow Battery Applications
Authors: Chu Fuqiang , Chu Xufeng , Lv Teng , Chen Zhouyi , Ren Yurong , Zhang Shuai , Yuan Ningyi , Lin Bencai , Ding Jianning 
Published: September 2019

AbstractAmphoteric membranes were obtained from imidazolium‐functionalized polyphenylene oxide (ImPPO) and sulfonated poly(ether ether ketone) (SPEEK) for an all‐vanadium redox flow battery (VRFB) application. The SPEEK/ImPPO amphoteric membranes showed a considerably lower swelling degree and water uptake compared to those of pure SPEEK membranes, owing to the formation of ionic bonds between the cationic imidazolium groups of ImPPO and the anionic sulfonate groups of SPEEK. The cationic imidazolium groups of the ImPPO exhibited a Donnan exclusion effect on vanadium ions; therefore, the amphoteric membranes showed a much lower vanadium permeability than the pure SPEEK membrane. In addition, the vanadium permeability of the amphoteric membranes deceased with an increase in the ImPPO content. SPEEK‐ImPPO20 with 20 wt% ImPPO showed a vanadium permeability of 0.43×10−9 cm2 s−1 at room temperature, which is 17 times lower than that of Nafion 212 (8×10−9 cm2 s−1). The VRFB assembled with SPEEK‐ImPPO20 showed a coulombic efficiency of 97.2 % and a voltage efficiency of 85.8 % at a current density of 60 mA cm−2, whereas the values for Nafion 212 were 92.4 % and 86.7 % under the same conditions. In addition, the VRFB assembled with SPEEK‐ImPPO20 exhibited much better capacity retention than that assembled with Nafion 212. These results indicate that the SPEEK‐ImPPO amphoteric membrane is a promising material for VRFB applications.
Thiolate Bridged Gold(I)–NHC Catalysts: New Approach for Catalyst Design and its Application to Trapping Catalytic Intermediates
Authors: Visbal Renso , Herrera Raquel P. , Gimeno M. Concepción 
Published: September 2019

AbstractNew dinuclear N‐heterocyclic gold complexes with bridging thiolate ligands have been designed as catalytic precursors with desired properties such as stability, recyclability and that do not require additives. The dinuclear compound [(AuNHC)2(μ‐SC6F5)]OTf could slowly release the active catalytic species [Au(NHC)]+ and the precursor [Au(SC6F5)(NHC)] in solution, which means that both species would remain stable throughout the catalytic cycle and the pre‐catalyst could easily be recovered. The properties exhibited by the complexes have been taken advantage of to gain new insights on the gold‐catalyzed hydroalkoxylation of alkynes, with the aim of clarifying all the steps of the catalytic cycle, together with the characterization of intermediates and final products. Isolation and characterization of the pure final spiroketals and the thermodynamic intermediate have been achieved for the first time. Moreover, the kinetic intermediate has also been detected for the first time.
Mechanistic Insights into Rhenium‐Catalyzed Regioselective C‐Alkenylation of Phenols with Internal Alkynes
Authors: Murai Masahito , Yamamoto Masaki , Takai Kazuhiko 
Published: September 2019

AbstractA (μ‐aryloxo)rhenium complex was isolated and confirmed as a key precatalyst for rhenium‐catalyzed ortho‐alkenylation (C‐alkenylation) of unprotected phenols with alkynes. The reaction exclusively provided ortho‐alkenylphenols; the formation of para or multiply alkenylated phenols and hydrophenoxylation (O‐alkenylation) products was not observed. Several mechanistic experiments excluded a classical Friedel–Crafts‐type mechanism, leading to the proposed phenolic hydroxyl group assisted electrophilic alkenylation as the most plausible reaction mechanism. For this purpose, the use of rhenium, a metal between the early and late transition metals in the periodic table, was key for the activation of both the soft carbon–carbon triple bond of the alkyne and the hard oxygen atom of the phenol, at the same time. ortho‐Selective alkenylation with allenes also provided the corresponding adducts with a substitution pattern different from that obtained by the addition reaction with alkynes.