bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Stereoconvergent Tsuji–Trost Reaction in the Synthesis of Cyclohexenyl Nucleosides
Authors: Esposito Anna , di Giovanni Concetta , De Fenza Maria , Talarico Giovanni , Chino Marco , Palumbo Giovanni , Guaragna Annalisa , D'Alonzo Daniele 
Published: December 2019

AbstractA highly regio‐ and stereoselective route to d‐ and l‐cyclohexenyl nucleosides has been devised, using the Tsuji–Trost reaction as the key step. Contrarily to the widely accepted mechanism (involving a net retention of configuration), the reaction proceeded in a highly stereoconvergent manner, providing cis nucleosides regardless of the relative configuration of the starting materials. DFT calculations confirmed the experimental data while suggesting the origin of the stereochemical reaction outcome.
Experimental Evidence for the Incorporation of Two Metals at Equivalent Lattice Positions in Mixed‐Metal Metal–Organic Frameworks
Authors: Bitzer Johannes , Otterbach Steffen , Thangavel Kavipriya , Kultaeva Anastasia , Schmid Rochus , Pöppl Andreas , Kleist Wolfgang 
Published: December 2019

AbstractMetal–organic frameworks containing multiple metals distributed over crystallographically equivalent framework positions (mixed‐metal MOFs) represent an interesting class of materials, since the close vicinity of isolated metal centers often gives rise to synergistic effects. However, appropriate characterization techniques for detailed investigations of these mixed‐metal metal–organic framework materials, particularly addressing the distribution of metals within the lattice, are rarely available. The synthesis of mixed‐metal FeCuBTC materials in direct syntheses proved to be difficult and only a thorough characterization using various techniques, like powder X‐ray diffraction, X‐ray absorption spectroscopy and electron paramagnetic resonance spectroscopy, unambiguously evidenced the formation of a mixed‐metal FeCuBTC material with HKUST‐1 structure, which contained bimetallic Fe−Cu paddlewheels as well as monometallic Cu−Cu and Fe−Fe units under optimized synthesis conditions. The in‐depth characterization showed that other synthetic procedures led to impurities, which contained the majority of the applied iron and were impossible or difficult to identify using solely standard characterization techniques. Therefore, this study shows the necessity to characterize mixed‐metal MOFs extensively to unambiguously prove the incorporation of both metals at the desired positions. The controlled positioning of metal centers in mixed‐metal metal–organic framework materials and the thorough characterization thereof is particularly important to derive structure–property or structure–activity correlations.
Absence of left bundle branch block and blood urea nitrogen predict improvement in left ventricular ejection fraction in patients with cardiomyopathy and wearable cardioverter defibrillators
Authors: Mehta Nikhil A. , Abdulsalam Nashwa , Kouides Ruth , Ahmed Hamdy , Atif Raisa , Shah Abrar , Taylor Sarah , Chuprun Dmitry , Huang David , Rao Mohan 
Published: December 2019

AbstractObjectiveTo identify predictors of left ventricular ejection fraction (LVEF) improvement in patients with newly detected cardiomyopathy using wearable cardioverter defibrillators (WCDs).BackgroundWCDs are useful in preventing sudden cardiac death in patients with reduced LVEF <35% while awaiting implantable cardioverter defibrillator (ICD) placement. In many patients, LVEF improves and an ICD is not indicated.MethodsPatients who received WCDs from November 2013 to November 2015 were identified and followed over a period of 2 years. Clinical variables were examined. The primary outcome was improvement in LVEF ≥35%. Predictors of outcome were determined using a multivariate logistic regression model.ResultsA total of 179 patients were followed. Median age was 65 (interquartile range [IQR]: 56, 73) years, 69.3% were men. Median baseline LVEF was 20% (IQR: 15, 30). LVEF improved ≥35% in 47.5% patients, with patients being younger (62 vs 68.5 years, P = .006), having lower blood urea nitrogen (BUN) (19 vs 24 mg/dL, P = .002), fewer left bundle branch block (LBBB 9.5% vs 25.8%, P = .004), shorter QRS duration (98 vs 112 ms, P < .001), and higher use of angiotensin converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) (92.9% vs 74.4%, P = .001) compared to those without LVEF improvement. Absence of LBBB (odds ratio [OR] 0.28, 95% confidence interval [CI] 0.11‐0.70), lower BUN (OR 0.13, 95% CI 0.02‐0.76), and ACEI/ARB use (OR 3.53, 95% CI 1.28‐9.69) were identified as independent predictors. Ventricular tachycardia/ventricular fibrillation was observed in three patients, all of whom received successful WCD shocks.ConclusionAbsence of LBBB, lower BUN, and ACEI/ARB use predicts LVEF improvement. WCDs help treat arrhythmic events.
Potentially burdensome end‐of‐life transitions among nursing home residents with poor‐prognosis cancer
Authors: Lage Daniel E. , DuMontier Clark , Lee Yoojin , Nipp Ryan D. , Mitchell Susan L. , Temel Jennifer S. , El‐Jawahri Areej , Berry Sarah D. 
Published: December 2019

BackgroundThis study examined factors associated with potentially burdensome end‐of‐life (EOL) transitions between care settings among older adults with advanced cancer in nursing homes (NHs).MethodsA retrospective analysis of deceased older NH residents with poor‐prognosis solid tumors was conducted with Medicare claims and the Minimum Data Set. A potentially burdensome transition was defined as 2 or more hospitalizations or an intensive care unit admission in the last 90 days of life.ResultsAmong 34,670 subjects, many had moderate to severe cognitive impairment (53.8%), full dependence in activities of daily living (ADLs; 66.5%), and comorbidities such as congestive heart failure (CHF; 29.3%) and chronic obstructive pulmonary disease (34.1%). Only 56.3% of the patients used hospice at any time in the 90 days before death; 36.0% of the patients experienced a potentially burdensome EOL transition, and this was higher among patients who did not receive hospice (45.4% vs 28.7%; P < .01). In multivariable analyses, full dependence in ADLs (odds ratio [OR], 1.70; P < .01), CHF (OR, 1.48; P < .01), and chronic obstructive pulmonary disease (OR, 1.28; P < .01) were associated with a higher risk of burdensome EOL transitions. Those with do‐not‐resuscitate directives (OR, 0.60; P < .01) and impaired cognition (OR, 0.89; P < .01) had lower odds of burdensome EOL transitions.ConclusionsNH residents with advanced cancer have substantial comorbidities and functional impairment, yet more than a third experience potentially burdensome EOL transitions. These findings help to identify a population at risk for poor EOL outcomes in order to target interventions, and they point to the importance of advanced care planning in this population.
Facile, Rapid, and Well‐Controlled Preparation of Pt Nanoparticles Decorated on Single Surface of Mos2 Nanosheets and Application in HER
Authors: Liao Yunlong , Zhang Cunjin , Ji Jing , Jin Peng , Zhou Xiaomeng 
Published: December 2019

AbstractRecently, asymmetrically functionalized two‐dimensional (2D) nanomaterials have attracted fevered interest as excellent candidates for building blocks of multifunctional and multidimensional systems due to the structural symmetry‐breaking. However, their preparation process typically involves high vacuum environment or specific equipment, and the obtained samples have poor stability and low yield. In this study, a facile approach has been developed to achieve the asymmetric deposition of platinum nanoparticles (NPs) onto single side of the molybdenum disulfide (MoS2) nanosheets by pyrogenic decomposition and in‐situ functionalization. By tuning the platinum precursor to MoS2 ratio, the size distribution and morphology of the Pt NPs can be well controlled. The asymmetrical decoration of Pt NPs on MoS2 nanosheets (Pt−MoS2) may result from the superior interactions between Pt NPs and MoS2 basal surface, which are stronger than the van der Waals force between adjacent MoS2 layers. Hydrogen evolution reaction (HER) results show that higher Pt loading yields better HER performance with low overpotential of 120 mV and superior Tafel slope of 28 mV ⋅ dec−1. Significantly, the current synthetic method can be used in the asymmetrical functionalization of other 2D nanosheets as well, and could greatly advance the facile preparation and practical applications of these asymmetric nanostructures.
OLAP parallel query processing in clouds with C‐ParGRES
Authors: W. M. Ribeiro Marcello , A. B. Lima Alexandre , de Oliveira Daniel 
Published: December 2019

SummaryThe advent of big data technologies has changed the way many companies manage their data. Several companies moved their data to the cloud using the concept of database‐as‐a‐service (DBaaS). Moving databases to the cloud presents several challenges related to flexible and scalable management of data. Although some of these companies migrated to NoSQL databases, most still rely on relational databases in the cloud to manage data, especially data that is critical to the decision making process. Online analytical processing (OLAP) queries take a long time to be processed, thus demanding high‐performance capabilities from their associated database systems to get results in a feasible time. In this article, we propose a middleware solution that can be deployed in any cloud provider, named C‐ParGRES, which explores database replication and interquery and intraquery parallelism to efficiently support OLAP queries in the cloud. C‐ParGRES is an extension of ParGRES, an open‐source database cluster middleware for high‐performance OLAP query processing in clusters. C‐ParGRES exploits cloud capabilities such as on‐demand resource provisioning and elasticity. In addition, C‐ParGRES can create multiple and independent virtual clusters for different database and users. We evaluate C‐ParGRES with two real‐world OLAP applications, both from the Brazilian Institute of Geography and Statistics. Results show that C‐ParGRES is a cost‐effective solution for OLAP query processing in the cloud.
New public auditing protocol based on homomorphic tags for secure cloud storage
Authors: Zhang Jindan , Wang Baocang , Ogiela Marek R. , Wang Xu An , Sangaiah Arun Kumar 
Published: December 2019

SummaryOutsourcing datum to the cloud servers is more and more popular for most data owners and enterprises. However, how to ensure the outsourced datum to be kept secure is very important. Especially, how to check the outsourced datum's integrity is a very challenge problem. Until now, there are many cryptographic protocols proposed to solve this problem, such as (dynamic) provable data position protocol, (dynamic) proof of retrievability protocol, etc. Recently, Tian et al proposed a dynamic‐hash‐table‐based public auditing scheme for secure cloud storage, which aims at simultaneously supporting secure dynamic data updating and secure public auditing for cloud storage. However, we find a security flaw in this protocol; concretely, the signature algorithm for the data blocks in their protocol is not secure; the cloud servers can easily modify the outsourced data blocks without detecting. Finally, we give a new protocol by using homomorphic tags based on their protocol and roughly analysis its security.
Heterogeneous differential privacy for vertically partitioned databases
Authors: Xia Yang , Zhu Tianqing , Ding Xiaofeng , Jin Hai , Zou Deqing 
Published: December 2019

SummaryExisting privacy‐preserving approaches are generally designed to provide privacy guarantee for individual data in a database, which reduces the utility of the database for data analysis. In this paper, we propose a novel differential privacy mechanism to preserve the heterogeneous privacy of a vertically partitioned database based on attributes. We first present the concept of privacy label, which characterizes the privacy information of the database and is instantiated by the classification. Then, we use an information‐based method to systematically explore the dependencies between all attributes and the privacy label. We finally assign privacy weights to every attribute and design a heterogeneous mechanism according to the basic Laplace mechanism. Evaluations using real datasets demonstrate that the proposed mechanism achieves a balanced privacy and utility.
Can Nanoplastics Alter Cell Membranes?
Authors: Hollóczki Oldamur , Gehrke Sascha 
Published: December 2019

AbstractThe front cover artwork is provided by the junior research group of Dr. Hollóczki at the University of Bonn. The image shows how the plastic waste, after fragmentation into nanoplastics, can affect lipid bilayers by forming a network of polymer chains that stretch throughout the hydrophobic core of the membrane. Read the full text of the Communication at 10.1002/cphc.201900481.
Evaluating and presenting uncertainty in model‐based unconstrained ordination
Authors: Hoegh Andrew , Roberts David W. 
Published: December 2019

AbstractVariability in ecological community composition is often analyzed by recording the presence or abundance of taxa in sample units, calculating a symmetric matrix of pairwise distances or dissimilarities among sample units and then mapping the resulting matrix to a low‐dimensional representation through methods collectively called ordination. Unconstrained ordination only uses taxon composition data, without any environmental or experimental covariates, to infer latent compositional gradients associated with the sampling units. Commonly, such distance‐based methods have been used for ordination, but recently there has been a shift toward model‐based approaches. Model‐based unconstrained ordinations are commonly formulated using a Bayesian latent factor model that permits uncertainty assessment for parameters, including the latent factors that correspond to gradients in community composition. While model‐based methods have the additional benefit of addressing uncertainty in the estimated gradients, typically the current practice is to report point estimates without summarizing uncertainty. To demonstrate the uncertainty present in model‐based unconstrained ordination, the well‐known spider and dune data sets were analyzed and shown to have large uncertainty in the ordination projections. Hence to understand the factors that contribute to the uncertainty, simulation studies were conducted to assess the impact of additional sampling units or species to help inform future ordination studies that seek to minimize variability in the latent factors. Accurate reporting of uncertainty is an important part of transparency in the scientific process; thus, a model‐based approach that accounts for uncertainty is valuable. An R package, UncertainOrd, contains visualization tools that accurately represent estimates of the gradients in community composition in the presence of uncertainty.
How does the bed surface impact low‐magnitude bedload transport rates over gravel‐bed rivers?
Authors: Perret Emeline , Berni Céline , Camenen Benoît 
Published: December 2019

AbstractBedload transport is a complex phenomenon that is not well understood, especially for poorly sorted sediment and low transport rates, which is what is typically found in alpine gravel‐bed rivers. In this paper, the interaction between bedload rate, bed stability and flow is investigated using flume experiments. Significant differences in bedload rates were observed for experiments conducted on beds formed with the same gravel material but presenting diverse arrangements and bedforms. Tests were performed under regimes of low transport rate, which are mainly controlled by gravel‐bed roughness. Different scales of roughness were identified using the statistical characteristics of detailed bed elevation measurements: grain, structure and large bedform scales. The role played by these different roughness scales in bedload dynamics was examined. For quasi‐flat beds, bed stability was quantified using a combination of bed surface criteria describing grain and structure scales. It was found that bed stability affects the bedload rate directly and not only through its influence on the flow or on the incipient motion. For beds with large bedforms, the analysis of bedload dynamics also showed the importance of accounting for effective bed shear stress distributions. An empirical bedload model for low transport regimes was suggested. Compared with previous formulae developed for alpine rivers, this model accounts for bed stability and distribution of effective bed shear stress. It significantly improves the understanding of gravel dynamics over complex beds such as arranged beds or those with large bedforms. However, further tests are needed to use the model outside the range of conditions of this study. © 2019 John Wiley & Sons, Ltd.
Retinotopy of emotion: Perception of negatively valenced stimuli presented at different spatial locations as revealed by event‐related potentials
Authors: Carretié Luis , Méndez‐Bértolo Constantino , Bódalo Cristina , Hernández‐Lorca María , Fernández‐Folgueiras Uxía , Fondevila Sabela , Giménez‐Fernández Tamara 
Published: December 2019

AbstractScarce previous data on how the location where an emotional stimulus appears in the visual scene modulates its perception suggest that, for functional reasons, a perceptual advantage may exist, vertically, for stimuli presented at the lower visual field (LoVF) and, horizontally, for stimuli presented at the left visual field (LeVF). However, this issue has been explored through a limited number of spatial locations, usually in a single spatial dimension (e.g., horizontal) and invariant eccentricities. Event‐related potentials (ERPs) were recorded from 39 participants perceiving brief neutral (wheels) and emotional stimuli (spiders) presented at 17 different locations, one foveal and 16 at different peripheral coordinates. As a secondary scope, we explored the role of the magnocellular (M) and the parvocellular (P) visual pathways by presenting an isoluminant/heterochromatic (P‐biased) and a heteroluminant/isochromatic version (M‐biased) of each stimulus. Emo > Neu effects were observed in PN1 (120 ms) for stimuli located at fovea, and in PN2 (215 ms) for stimuli located both at fovea and diverse peripheral regions. A factorial approach to these effects further revealed that: (a) emotional stimuli presented in the periphery are efficiently perceived, without evident decrease from para‐ to perifovea; (b) peripheral Emo > Neu effects are reflected 95 ms later than foveal Emo > Neu effects in ERPs; (c) LoVF is more involved than UVF in these effects; (d) our data fail to support the LeVF advantage previously reported, and (e) Emo > Neu effects were significant for both M and P stimuli.
The effect of outdoor smoking ban: Evidence from Korea
Authors: Ko Hansoo 
Published: December 2019

AbstractTo address exposure to secondhand smoke, which is highly prevalent in Korea, local governments have implemented smoking bans at open public places (parks, bus stops, and school zones) since 2011. Exploiting temporal and spatial variation in the implementation dates of these bans, this study estimates their causal effects on individual smoking behavior. The individual‐level longitudinal data from the 2009–2017 Korean Labor and Income Panel Study are linked to the smoking ban legislation information from the National Law Information Center. I find robust evidence that outdoor smoking bans increased the probability of making a quit attempt by 16%. This effect appears immediately after a ban goes into effect and lasts for three or more years. People who spend more time outdoors are more likely to change smoking behavior. I also find heterogeneity in effects across the amount of monetary penalty. Whereas the policy change did not affect the prevalence of smoking overall, higher penalties had stronger impacts on reducing the intensity of smoking and increasing the propensity to try to quit.
Sex‐specific analysis of renal cell carcinoma histology and survival in Japan: A population‐based study 2004 to 2016
Authors: Zaitsu Masayoshi , Toyokawa Satoshi , Takeuchi Takumi , Kobayashi Yasuki , Kawachi Ichiro 
Published: December 2019

AbstractBackground and aimsIn Western countries, sex differences in renal cell carcinoma (RCC) histology and survival have been previously described: compared with men, clear cell subtype is more common but overall prognosis is better among women. The goal of the present study was to examine sex differences in RCC histology and survival in Japan, using a large‐scale population‐based data set.MethodsWith the use of a population‐based cancer registry in Japan (2004‐2016), patients with primary RCC were followed for 5 years (median follow‐up time 2.1 years). We distinguished histological subtypes of clear cell, papillary, and chromophobe from “others” subtype. Sex‐specific prevalence ratio (PR) for each histological subtype was estimated by Poisson regression with robust variance, adjusted for age and year of diagnosis. Sex‐specific survival rates were estimated by Cox proportional hazard regression, adjusted for age, year of diagnosis, histological subtypes, and other prognostic variables, with multiple imputation.ResultsThe prevalence of clear cell and “others” subtypes was similar between men and women among all the 5265 study subjects during the 12 years of study (clear cell, male 88.6% vs female 87.1%; “others“, male 5.3% vs female 5.3%). However, papillary subtype was less common among women than men (male 4.6% vs female 2.8%; PR = 0.63; 95% CI, 0.45‐0.88), while chromophobe subtype was more common among women (male 1.6% vs female 4.8%; PR = 3.18; 95% CI, 2.26‐4.47). Although “others” subtype (but not papillary/chromophobe subtypes) independently predicted prognosis (HR = 1.74; 95% CI, 1.32‐2.30), no sex differences were observed in RCC survival.ConclusionWe did not observe a statistically significant difference in the prevalence of clear cell subtype between men and women in Japan, which differs from the pattern previously described in Western countries. Sex differences in RCC histology may not affect RCC survival in this population.
Fracture toughness and crack resistance curves of acrylic bone cements
Authors: Ziegler Tobias , Jaeger Raimund 
Published: December 2019

AbstractThe fracture toughness KIc of 11 clinically used acrylic bone cements was studied in air at room temperature with single edge V‐notched beam specimens. By driving the crack step‐wise through the specimens, crack resistance curves (“R‐curves”) were recorded. One group of bone cements showed an increase of the fracture toughness with increasing crack length (including CMW1+G and several Palacos bone cements) whereas another group (including Simplex, SmartSet, Copal and some Palacos bone cements) did not exhibit an R‐curve behavior. The plateau values for KIc ranged from 0.93 MPa√m (Simplex P) to 1.98 MPa√m (Palacos R+G). The observation of the crack growth with an optical microscope revealed some mechanisms influencing the crack growth like the formation of microcracks in the extended damage zone of the crack tip, the attraction of the crack by inclusions or the shielding of the crack tip by bridges in the wake of the crack. Furthermore, bone cements could be distinguished by the pattern of the path the crack followed during propagation. The crack pattern of CMW1+G provides a possible explanation of the distinct R‐curve behavior of this cement.