bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tailoring FeN4 Sites with Edge Enrichment for Boosted Oxygen Reduction Performance in Proton Exchange Membrane Fuel Cell
Authors: Fu Xiaogang , Li Na , Ren Bohua , Jiang Gaopeng , Liu Yanru , Hassan Fathy M. , Su Dong , Zhu Jianbing , Yang Lin , Bai Zhengyu , Cano Zachary P. , Yu Aiping , Chen Zhongwei 
Published: January 2019

AbstractTransition metal atoms with corresponding nitrogen coordination are widely proposed as catalytic centers for the oxygen reduction reaction (ORR) in metal–nitrogen–carbon (M–N–C) catalysts. Here, an effective strategy that can tailor Fe–N–C catalysts to simultaneously enrich the number of active sites while boosting their intrinsic activity and utilization is reported. This is achieved by edge engineering of FeN4 sites via a simple ammonium chloride salt‐assisted approach, where a high fraction of FeN4 sites are preferentially generated and hosted in a graphene‐like porous scaffold. Theoretical calculations reveal that the FeN4 moieties with adjacent pore defects are likely to be more active than the nondefective configuration. Coupled with the facilitated accessibility of active sites, this prepared catalyst, when applied in a practical H2–air proton exchange membrane fuel cell, delivers a remarkable peak power density of 0.43 W cm−2, ranking it as one of the most active M–N–C catalysts reported to date. This work provides a new avenue for boosting ORR activity by edge manipulation of FeN4 sites.
On the steady‐state drop size distribution in stirred vessels. Part II: Effect of continuous phase viscosity
Authors: Carrillo De Hert Sergio , Rodgers Thomas L. 
Published: January 2019

AbstractIn Part I, we used silicon oils with viscosities across six orders of magnitude to investigate the effect of the dispersed phase viscosity on the droplet size distribution of dilute emulsions. In this study, we extended Part I by using three glucose aqueous solutions to thicken the continuous phases, approximately an order of magnitude while keeping the Power number constant. It was found that increasing the continuous phase viscosity decreases the maximum drop size despite having drops well above the Kolmogorov lengthscale. Our results are in disagreement with the mechanistic models for the turbulent inertia regime. The results were explained using the full turbulent energy spectrum proposed by Pope instead of the Kolmogorov −5/3 spectrum. Our analysis revealed that most of the steady‐state drop sizes do not fall in the isotropic turbulence size range.
Understanding the Revised SI: Background, Consequences, and Perspectives
Authors: Liebisch Tara Cubel , Stenger Jörn , Ullrich Joachim 
Published: January 2019

AbstractThis article expounds the significance of the revision of the international system of units, the SI, approved by the General Conference on Weights and Measures (CGPM) in 2018. The revised SI implements a construct of a system of units based on fixing the numerical values of constants of nature, the “defining constants.” This fundamental development in the SI is not only elegant and infinitely sustainable, but moreover will drive future technological innovation. This article provides an historical overview and discusses the underlying principles and consequences of the revised SI: from the history of Planck's proposal for creating a system of units “valid for all times and civilizations,” to the scientific and technological motivations for the revision and the expected resulting innovations.
Charakterisierung eines großen Enzym‐Wirkstoff‐Komplexes mittels protonendetektierter Festkörper‐NMR ohne Deuterierung
Authors: Vasa Suresh K. , Singh Himanshu , Grohe Kristof , Linser Rasmus 
Published: January 2019

AbstractFestkörper‐NMR‐Spektroskopie ermöglicht seit einiger Zeit Strukturbiologie mit Kleinstmengen nichtdeuterierter Proteinproben, wodurch die biochemische Probenbereitstellung signifikant erleichtert wird. Trotz dieses Fortschrittes hat sich die erfolgreiche und umfassende Charakterisierung komplexerer Spinsysteme bisher auf traditionelle 13C‐detektierte Methodik oder Deuterierung gestützt. Dies gilt insbesondere für Proteine mit höchstem Molekulargewicht. Anhand eines 29 kDa Carboanhydrase‐Acetazolamid‐Komplexes zeigen wir hier, dass verschiedene Bereiche festkörper‐NMR‐spektroskopischer Charakterisierung eines komplexen Spinsystems mithilfe einer nichtdeuterierten 500 μg Probenmenge erfolgreich bestritten werden können, wenn adäquate spektroskopische Methodik verwendet wird. Der hier gezeigte Zugang zu Proteinstruktur, Proteindynamik sowie biochemischen Parametern in Aminosäureseitenketten wie Histidinprotonierungszuständen wird vor allem für solche Proteine wichtig sein, die nicht durch Expression in E. coli zu erhalten sind.
Association of Geography and Access to Health Care Providers With Long‐Term Prescription Opioid Use in Medicare Patients With Severe Osteoarthritis: A Cohort Study
Authors: Desai Rishi J. , Jin Yinzhu , Franklin Patricia D. , Lee Yvonne C. , Bateman Brian T. , Lii Joyce , Solomon Daniel H. , Katz Jeffrey N. , Kim Seoyoung C. 
Published: January 2019

ObjectiveTo evaluate the variation in long‐term opioid use in osteoarthritis (OA) patients according to geography and health care access.MethodsWe designed an observational cohort study among OA patients undergoing total joint replacement (TJR) in the Medicare program (2010 through 2014). The independent variables of interest were the state of residence and health care access, which was quantified at the primary care service area (PCSA) level as categories of number of practicing primary care providers (PCPs) and categories of rheumatologists per 1,000 Medicare beneficiaries. The percentage of OA patients taking long‐term opioids (≥90 days in the 360‐day period immediately preceding TJR) within each PCSA was the outcome variable in a multilevel, generalized linear regression model, adjusting for case‐mix at the PCSA level and for policies, including rigor of prescription drug monitoring programs and legalized medical marijuana, at the state level.ResultsA total of 358,121 patients with advanced OA, with a mean age of 74 years, were included from 4,080 PCSAs. The unadjusted mean percentage of long‐term opioid users varied widely across states, ranging from 8.9% (Minnesota) to 26.4% (Alabama), and this variation persisted in the adjusted models. Access to PCPs was only modestly associated with rates of long‐term opioid use between PCSAs with highest (>8.6) versus lowest (<3.6) concentration of PCPs (adjusted mean difference 1.4% [95% confidence interval 0.8%, 2.0%]), while access to rheumatologists was not associated with long‐term opioid use.ConclusionWe note a substantial statewide variation in rates of long‐term treatment with opioids in OA, which is not fully explained by the differences in access to health care providers, varying case‐mix, or state‐level policies.
Efficacy and safety of FOLFIRI/aflibercept in second‐line treatment of metastatic colorectal cancer in a real‐world population: Prognostic and predictive markers
Authors: Fernández Montes Ana , Martínez Lago Nieves , Covela Rúa Marta , de la Cámara Gómez Juan , González Villaroel Paula , Méndez Méndez José Carlos , Jorge Fernández Mónica , Salgado Fernández Mercedes , Reboredo López Margarita , Quintero Aldana Guillermo , Luz Pellón Augusto María , Graña Suárez Begoña , García Gómez Jesús 
Published: January 2019

AbstractPurposeThe phase III VELOUR trial demonstrated efficacy with combined FOLFIRI‐aflibercept in patients with metastatic colorectal cancer previously treated with oxaliplatin with or without bevacizumab versus placebo. The effect of FOLFIRI‐aflibercept in routine clinical practice was evaluated.Methods/PatientsOverall survival (OS), progression‐free survival (PFS), response and safety were analysed for 78 patients treated with FOLFIRI‐aflibercept at six GITuD institutions. Exploratory analyses of prognostic and predictive markers of efficacy were performed.ResultsPatients had good general status (PS 0‐1 96.2%), tumours were mostly RAS‐mutant (75.6%), synchronous (71.8%), and left‐sided (71.8%). Prior therapy included bevacizumab (47.4%) and anti‐EGFR agents (12.8%). PFS was longer for metachronous than synchronous tumours (11.0 vs 5.0 months, P = 0.028), and for left‐colon tumours (7.0 vs 3.0 months, P = 0.044). RAS‐mutant status, first‐line treatment and primary tumour surgery did not impact PFS. The disease control rate was 70.5%. The most common grade 3/4 toxicities were neutropenia (15.3%), asthenia (10.3%), diarrhea and mucositis (6.4% each). Dysphonia was reported in 39.7% of patients, and grade 3 hypertension in 3.8%. Development of hypertension (any grade) was significantly associated with a reduced risk of progression by multivariate analysis (HR = 2.7; 95%CI 1.3‐5.4; P = 0.001).ConclusionsEfficacy with FOLFIRI‐aflibercept in a real‐life population was in line with results from the pivotal trial and toxicity was manageable with treatment adaptation. Survival outcomes were not impacted by primary tumour location, RAS‐mutant status, first‐line treatment or primary tumour surgery. Hypertension may be a surrogate marker of efficacy in this patient population.
Monocyte‐predominant engraftment, cytokine levels and early transplant‐related complications in pediatric hematopoietic stem cell recipients
Authors: Maximova Natalia , Granzotto Marilena , Barbieri Francesca , Marcuzzi Annalisa , Tommasini Alberto , Monasta Lorenzo , Simeone Roberto , Zanon Davide , Sala Roberto 
Published: January 2019

AbstractMyeloablative conditioning is a well‐established procedure that precedes hematopoietic stem cell transplantation (HSCT), particularly in pediatric patients. In the period directly following transplantation, several factors may contribute to complications that lead to the activation or damage of endothelial cells, involved in the pathogenesis of vascular endothelial syndromes (VES). However, to date, sufficiently specific and sensitive diagnostic markers for the various forms of VES have not been identified. This was a retrospective single‐center study of patients who underwent allogeneic HSCT. For this cohort of patients, parameters including type of engraftment, donor characteristics, and cytokine production were measured and correlated with a high prevalence of short‐term complications after HSCT. The aim of this study was to identify specific parameters useful for improving diagnostics and predicting adverse effects in VES. We confirmed that monocyte‐predominant engraftment was related to a higher risk for an early transplant‐related complication termed sinusoidal obstruction syndrome (SOS). The increased production of specific cytokines, in particular RANTES, represents a marker associated with prevalent engraftment. In addition, patients undergoing prophylaxis with defibrotide had “classical” engraftment, a common cytokine profile and a lower incidence of life‐threatening transplant‐related complications. The beneficial effect of defibrotide might be a starting point for developing selective prophylaxis for patients with monocyte engraftment to prevent severe early transplant‐related complications.
Left ventricular remodeling and function after transapical versus transfemoral transcatheter aortic valve replacement
Authors: Al‐Hijji Mohammed A. , Zack Chad J. , Nkomo Vuyisile T. , Pislaru Sorin V. , Pellikka Patricia A. , Reeder Guy S. , Greason Kevin L. , Rihal Charanjit S. , Eleid Mackram F. 
Published: January 2019

AbstractBackgroundThe effect of utilizing transapical (TA) access for transcatheter aortic valve replacement (TAVR) on cardiac function has not been well studied.AimsThe aim of this retrospective study is to determine the direct effects of TA access for TAVR on myocardial function parameters and their correlation with 4‐year survival.MethodsThree hundred and thirty propensity matched patients, who underwent TAVR using Sapien valve (Edwards Lifesciences Corp, Irvine, CA) between February 15, 2012 and June 17, 2016 (115 TA and 115 transfemoral [TF] routes) were studied. The pre‐ and 1 month post‐TAVR echocardiographic features of both groups were compared. The 4‐year survival in both groups was analyzed.ResultsBaseline clinical characteristics, diastolic function parameters, left ventricular (LV) chamber size, and ejection fraction were similar between matched TA and TF groups. At 1 month following TAVR, there was a significant increase in stroke volume index (SVI) in both TA (mean increase 7 cm3/m2; P = 0.03) and TF groups (mean increase 7 cm3/m2; P < 0.001). Left ventricular ejection fraction (LVEF) significantly increased post TF TAVR (mean increase 2%; P = 0.008), but no significant increase was observed post TA TAVR (mean increase 1%; P = 0.27). Both groups had significant improvement in aortic valve (AV) hemodynamics post‐TAVR (P < 0.001). Overall, there were no significant differences in the mean change of SVI, LVEF, or left ventricular end diastolic dimensions (LVEDDs) post TA versus TF TAVR. There was no significant difference in 4‐year survival in the TF compared to TA group (49% vs 50%, P = 0.43).ConclusionBoth TA and TF TAVR were equally associated with favorable changes in LV SVI and AV hemodynamics in 30 days. TA TAVR patients had similar 4 year survival to propensity matched TF TAVR; therefore, TA TAVR remains an acceptable alternative access route in patients not amenable to TF TAVR.
Transulnar access for coronary intervention in a 23‐year‐old with accelerated coronary atherosclerosis due to congenital aortic hypoplasia
Authors: Dawkins Jonathan D. , Cedars Ari M. , Schussler Jeffrey M. 
Published: January 2019

Key Clinical MessageThe use of alternative arterial access and advanced imaging is not only applicable to mainstream adult cardiology, but helpful and sometimes necessary in taking care of adult patients with complex congenital heart disease.
Bladder stone: “Must know” ultrasonographic signs
Authors: Koratala Abhilash , Vangapalli Ananthalaxmi , Bhattacharya Deepti , Lee Loy Justin 
Published: January 2019

Key Clinical MessagePoint‐of‐care ultrasonography by non‐radiology physicians has become a valuable bedside diagnostic tool. As urolithiasis is one of the commonest indications for sonographic examination, physicians need to be familiar with the characteristic features of stones, that is, acoustic shadowing on gray scale and twinkle artefact on color doppler imaging.
General Method for Synthesis Transition‐Metal Phosphide/Nitrogen and Phosphide Doped Carbon Materials with Yolk‐Shell Structure for Oxygen Reduction Reaction
Authors: Yu Yue , Ma Jun , Chen Changli , Fu Yuanyuan , Wang Yefei , Li Kai , Liao Yi , Zheng Lirong , Zuo Xia 
Published: January 2019

AbstractThe transition metal phosphides have gradually emerged as promising electrocatalysts candidate for oxygen reduction reaction in recent years. As a research hotspot of transition metal phosphides, exploring their mechanism of catalytic activity and the influence of unique morphology is of great significance. In this study, a series of yolk‐shell structure catalysts are fabricated only by pyrolyzing cyclophosphazene microspheres and metal salt without using any other templates, which M2P (M=Fe, Co, Ni) act as the core and N, P co‐doped carbon as the shell. The yolk‐shell structures aim to overcome the inferior conductivity and aggregation problems traditionally existed in application of transition metal phosphides through combination of transition metal phosphides and doped carbon materials. The prepared Fe2P/NPC, Co2P/NPC and Ni2P/NPC catalysts exhibit excellent ORR catalytic activity through the four‐electron pathway, together with large electrochemically active surface area, superior stability and admiring methanol tolerance.
Simulating Non‐linear Chemical and Physical (CAP) Dynamics of Signal Amplification By Reversible Exchange (SABRE)
Authors: Pravdivtsev Andrey N. , Hövener Jan‐Bernd 
Published: January 2019

AbstractThe hyperpolarization of nuclear spins by using parahydrogen (pH2) is a fascinating technique that allows spin polarization and thus the magnetic resonance signal to be increased by several orders of magnitude. Entirely new applications have become available. Signal amplification by reversible exchange (SABRE) is a relatively new method that is based on the reversible exchange of a substrate, catalyst and parahydrogen. SABRE is particularly interesting for in vivo medical and industrial applications, such as fast and low‐cost trace analysis or continuous signal enhancement. Ever since its discovery, many attempts have been made to model and understand SABRE, with various degrees of simplifications. In this work, we reduced the simplifications further, taking into account non‐linear chemical and physical (CAP) dynamics of several multi‐spin systems. A master equation was derived and realized using the MOIN open‐source software. The effects of different parameters (exchange rates, concentrations, spin–spin couplings) on relaxation and the polarization level have been evaluated and the results provide interesting insights into the mechanism of SABRE.
Ionic Liquid Stabilized Niobium Oxoclusters Catalyzing Oxidation of Sulfides with Exceptional Activity
Authors: Zhou Qingqing , Ye Man , Ma Wenbao , Li Difan , Ding Bingjie , Chen Manyu , Yao Yefeng , Gong Xueqing , Hou Zhenshan 
Published: January 2019

AbstractWe present here a new class of niobium oxoclusters that are stabilized effectively by carboxylate ionic liquids. These functionalized ILs are designated as [TBA][LA], [TBA][PA], and [TBA][HPA] in this work, in which TBA represents tetrabutylammonium and LA, PA, and HPA refer to lactate, propionate, 3‐hydroxypropionate anions, respectively. The as‐synthesized Nb oxoclusters have been characterized by use of elemental analysis, NMR, IR, XRD, TGA, HRTEM. It was found that [TBA][LA]‐stabilized Nb oxoclusters (Nb−OC@[TBA][LA]) are uniformly dispersed with an average particle size of 2–3 nm and afforded exceptionally high catalytic activity for the selective oxidation of various thioethers. The turnover number with Nb−OC@[TBA][LA] catalyst was over 56 000 at catalyst loading as low as 0.0033 mol % (1 ppm). Meantime, the catalyst also showed the high activity for the epoxidation of olefins and allylic alcohols by using only 0.065 mol % of catalyst (50 ppm). The characterization of 93Nb NMR spectra revealed that the Nb oxoclusters underwent structural transformation in the presence of H2O2 but regenerated to their initial state at the end of the reaction. In particular, the highly dispersed Nb oxoclusters can absorb a large amount of polar organic solvents and thus were swollen greatly, which exhibited “pseudo” liquid phase behavior, and enabled the substrate molecules to be highly accessible to the catalytic center of Nb oxocluster units.
Trapping of Stable [4n+1] π‐Electron Species from Peripherally Substituted, Conformationally Rigid, Antiaromatic Hexaphyrins
Authors: Firmansyah Dikhi , Hong Seong‐Jin , Dutta Ranjan , He Qing , Bae Jinhee , Jo Hongil , Kim Hakwon , Ok Kang Min , Lynch Vincent M. , Byon Hye Ryung , Sessler Jonathan L. , Lee Chang‐Hee 
Published: January 2019

AbstractPeripherally substituted antiaromatic naphthorosarins have been synthesized for the first time. The synthesis was accomplished by acid‐catalyzed condensation of naphthobipyrrole building blocks with aromatic aldehydes. The naphthobipyrrole building blocks were synthesized by simple oxidative coupling of the corresponding pyrrole substituted aromatics. Solid‐state structural analyses of the synthesized naphthorosarins revealed that the presence of meso‐2,6‐dichlorophenyl‐ and 5,6‐difluoro‐substitution substantially alter the geometry and properties of the naphthorosarins. The substituents affect the redox potentials as well and, in turn, the proton‐coupled electron‐transfer processes leading to the formation of one‐ and two‐electron reduced forms of the corresponding naphthorosarins. One particular naphthorosarin that bears both peripheral fluorine and meso‐2,6‐dichlorophenyl substituents forms a stable 25 π‐electron species upon treating with TFA that was characterized by single‐crystal X‐ray diffraction analysis. The current study underscores how structural modifications can be used to fine‐tune the electronic features of naphthorosarins, including stabilization of odd electron species.
Organic‐Inorganic Hybrid Perovskite Single Crystals: Crystallization, Molecular Structures, and Bandgap Engineering
Authors: Zuo Tiantian , He Xuexia , Hu Peng , Jiang Hui 
Published: January 2019

AbstractAs a novel active semiconducting material for optoelectronics, organic‐inorganic hybrid perovskites have attracted much attention due to the special advantages of the high light absorption coefficient, long diffusion length and high charge carrier mobility. The single crystals with low defects and free grain boundaries can provide an ideal platform to study the intrinsic photophysical properties and show better performance compared with its amorphous or polycrystalline states. The excellent physical properties of perovskite single crystals make them applied in many fields of solar cells, photodetectors, light‐emitting diodes, lasers, catalysis, etc. Here, the recent progress in the single crystal growth, molecular structures and the bandgap engineering of organic‐inorganic hybrid perovskite single crystals are introduced. The perspective and the future challenge are also provided.
Preparation of Ordered Mesoporous Alumina Supported‐ZnO/NiO Nanocomposite Using Supercritical Carbon Dioxide Impregnation and Its Photocatalytic Performance
Authors: Sun Lili , Han Pei , Tang Shaokun 
Published: January 2019

AbstractZnO/NiO nanoparticles supported on ordered mesoporous alumina (OMA) have been prepared by supercritical carbon dioxide impregnation using Zn(NO3)2 ⋅ 6H2O and Ni(NO3)2 ⋅ 6H2O as the precursors, supercritical carbon dioxide as the solvent and methanol as the co‐solvent. The ordered mesostructures of OMA were well‐maintained during the preparation. Ordered mesoporous alumina was prepared via solvent evaporation self‐assembly. The photocatalytic performance of ZnO/NiO/OMA composites for degradation of Congo Red was studied under simulated sunlight irradiation. The results showed that photocatalytic activity of the ZnO/NiO/OMA prepared by supercritical carbon dioxide impregnation was superior to those of commercial P‐25 and the composites prepared via the incipient wetness impregnation. The removal rate of Congo Red was found to be dependent on both the microstructure of the prepared ZnO/NiO/OMA composites and also the molar ratio of ZnO/NiO nanoparticles in OMA. The optimal molar ratio of ZnO/NiO was investigated to achieve a maximum photocatalytic activity.
Oxygen‐Functionalized Ultrathin Ti3C2Tx MXene for Enhanced Electrocatalytic Hydrogen Evolution
Authors: Jiang Yanan , Sun Tao , Xie Xi , Jiang Wei , Li Jia , Tian Bingbing , Su Chenliang 
Published: January 2019

AbstractTwo‐dimensional (2D) transition‐metal carbides (MXenes) are widely adopted as potential electrocatalysts for the hydrogen evolution reaction (HER) owing to their metallic conductivity, rich tunable surface chemistry, and atomic thickness with highly exposed active sites. Previously published theoretical results indicate that MXenes functionalized entirely with oxygen have lower ΔGH* for HER. However, MXenes contain many terminal F groups on the basal plane, which is detrimental to the HER. Herein, the development of an ultrathin Ti3C2 MXene nanosheet fully functionalized with oxygen is reported for the HER. The obtained oxygen‐functionalized Ti3C2 (Ti3C2Ox) exhibits a much higher HER activity (190 mV at 10 mA cm−2) than that of Ti3C2Tx (T=F, OH, and O). The improved HER performance is attributed to the highly active O sites on the basal plane of Ti3C2Tx MXenes. This study paves way for electrocatalytic applications of MXene materials by tuning their surface functional groups.