bluuebunny/crossref_metadata_2025_split huggingface dataset:
The formation of physician patient sharing networks in medicare: Exploring the effect of hospital affiliation
Authors: Linde Sebastian 
Published: October 2019

AbstractThis study explores the forces that drive the formation of physician patient sharing networks. In particular, I examine the degree to which hospital affiliation drives physicians' sharing of Medicare patients. Using a revealed preference framework where observed network links are taken to be pairwise stable, I estimate the physicians' pair‐specific values using a tetrad maximum score estimator that is robust to the presence of unobserved physician specific characteristics. I also control for a number of potentially confounding patient sharing channels, such as (a) common physician group or hospital system affiliation, (b) physician homophily, (c) knowledge complementarity, (d) patient side considerations related to both geographic proximity and insurance network participation, and (e) spillover from other collaborations. Focusing on the Chicago hospital referral region, I find that shared hospital affiliation accounts for 36.5% of the average pair‐specific utility from a link. Implications for reducing care fragmentation are discussed.
Kinetics and Mechanism of the Platinum(II)‐Catalyzed Hydroarylation of Vinyl Arenes with 1,2‐Dimethylindole
Authors: Zhang Zhibin , Liu Scott , Widenhoefer Ross A. 
Published: October 2019

AbstractThe mechanism of the intermolecular hydroarylation of vinyl arenes (1) with 1,2‐dimethylindole (2) catalyzed by PtCl2 has been evaluated through a combination of kinetic analysis, deuterium labeling studies, and stereochemical analysis. The results of these and additional experiments are consistent with a mechanism for hydroarylation involving rapid and reversible complexation of vinyl arene to the catalytically inactive platinum mono(vinyl arene)complex trans‐PtCl2(H2C=CHAr)(solvent) to form the reactive platinum bis(vinyl arene) complex trans‐PtCl2(H2C=CHAr)2, which undergoes turnover‐limiting, outer‐sphere attack of indole. Rapid protodemetallation of the resulting platinum alkyl complex releases product and regenerates the equilibrating mixture of platinum π‐vinyl arene complexes.
Strategies in cell‐free tissue‐engineered vascular grafts
Authors: Yuan Haoyong , Chen Chunyang , Liu Yuhong , Lu Ting , Wu Zhongshi 
Published: October 2019

AbstractCardiovascular diseases (CVD) remain the leading cause of morbidity and mortality in the world, among which coronary artery diseases (CAD) are the most common type of CVD. Coronary artery bypass grafting (CABG) using autologous vein and artery grafts is the typical surgical intervention for CAD patients. However, for patients whose autologous grafts are not available, there are no appropriate substitutes for vascular grafts. Investigation of tissue‐engineered vascular graft (TEVG) has persisted over decades with significant advancement, utilizing different types of biomaterials. In the past two decades, a great number of studies based on cell‐seeding strategies were reported. However, limitations of cell‐based strategies made clinical application difficult. With the understanding of stem cells and tissue remodeling process, strategies without cell‐seeding emerged as potential methods to achieve in situ regeneration. A cell‐free graft may recruit host cells and guide their participation in vascular remodeling. The grafts modified by bio‐active molecules showed good results in promoting in situ regeneration and exhibited potential to make the vascular grafts off‐the‐shelf. In this review, the strategies for cell‐free TEVG manufacturing were discussed, including the materials for fabricating TEVGs, the methods of functionalization to promote in situ regeneration, the challenges researchers faced in TEVG investigation, and finally the prospects in TEVG design.
Dietary Fish Oil Alters DNA Methylation of Genes Involved in Polyunsaturated Fatty Acid Biosynthesis in Muscle and Liver of Atlantic Salmon (Salmo salar)
Authors: Irvine Nicola A. , Ruyter Bente , Østbye Tone‐Kari , Sonesson Anna K. , Lillycrop Karen A. , Berge Gerd , Burdge Graham C. 
Published: October 2019

AbstractAdequate dietary supply of eicosapentaenoic acid (20:5n‐3) and docosahexaenoic acid (22:6n‐3) is required to maintain health and growth of Atlantic salmon (Salmo salar). However, salmon can also convert α‐linolenic acid (18:3n‐3) into eicosapentaenoic acid (20:5n‐3) and docosahexaenoic acid (22:6n‐3) by sequential desaturation and elongation reactions, which can be modified by 20:5n‐3 and 22:6n‐3 intake. In mammals, dietary 20:5n‐3 + 22:6n‐3 intake can modify Fads2 expression (Δ6 desaturase) via altered DNA methylation of its promoter. Decreasing dietary fish oil (FO) has been shown to increase Δ5fad expression in salmon liver. However, it is not known whether this is associated with changes in the DNA methylation of genes involved in polyunsaturated fatty acid synthesis. To address this, we investigated whether changing the proportions of dietary FO and vegetable oil altered the DNA methylation of Δ6fad_b, Δ5fad, Elovl2, and Elovl5_b promoters in liver and muscle from Atlantic salmon and whether any changes were associated with mRNA expression. Higher dietary FO content increased the proportions of 20:5n‐3 and 22:6n‐3 and decreased Δ6fad_b mRNA expression in liver, but there was no effect on Δ5fad, Elovl2, and Elovl5_b expression. There were significant differences between liver and skeletal muscle in the methylation of individual CpG loci in all four genes studied. Methylation of individual Δ6fad_b CpG loci was negatively related to its expression and to proportions of 20:5n‐3 and 22:6n‐3 in the liver. These findings suggest variations in dietary FO can induce gene‐, CpG locus‐, and tissue‐related changes in DNA methylation in salmon.
Role of trait combinations, habitat matrix, and network topology in metapopulation recovery from regional extinction
Authors: Giménez Luis , Robins Peter , Jenkins Stuart R. 
Published: October 2019

AbstractWe studied the role of oceanographic conditions and life history strategies on recovery after extinction in a metapopulation of marine organisms dispersing as pelagic larvae. We combined an age‐structured model with scenarios defined by realistic oceanographic conditions and species distribution along the Irish Sea coast (North Europe). Species life history strategies were modeled combining the dispersal behaviors with two levels of fecundity. Recovery times were quantified after simulating extinction in four regions. Two alternative strategies (high fecundity or larval tidal transport) led to short recovery times, irrespective of the effects of other drivers. Other strategies and low larval survival exacerbated the effects of oceanographic conditions on recovery times: longer times were associated with for example the presence of frontal zones isolating regions of extinction. Recovery times were well explained by the connectivity of each focal population with those located outside the area of extinction (which was higher in the so‐called small world topologies), but not by subsidies (direct connections with populations located nearby). Our work highlights the complexities involved in population recovery: specific trait combinations may blur the effects of the habitat matrix on recovery times; K‐strategists (i.e., with low fecundities) may achieve quick recovery if they possess the appropriate dispersal traits. High larval mortality can exacerbate the effect of oceanographic conditions and lead to heterogeneity in recovery times. Overall, processes driving whole network topologies rather than conditions surrounding local populations are the key to understand patterns of recovery.
Twice‐refocused stimulated echo diffusion imaging: Measuring diffusion time dependence at constant T1 weighting
Authors: Martin Jan , Endt Sebastian , Wetscherek Andreas , Kuder Tristan Anselm , Doerfler Arnd , Uder Michael , Hensel Bernhard , Laun Frederik Bernd 
Published: October 2019

PurposeDiffusion times longer than 50 ms are typically probed with stimulated‐echo sequences. Varying the diffusion time in stimulated‐echo sequences affects the T1 weighting of subcompartments, complicating the analysis of diffusion time dependence. Although inversion recovery preparation could be used to change the T1 weighting, it cannot ensure equal T1 weighting at arbitrary mixing times. In this article, a sequence that ensures constant T1 weighting over a wide range of diffusion times is presented.MethodsThe proposed sequence features 2 independent longitudinal storage periods: TM1 and TM2. Diffusion encoding is performed during TM1, effectively coupling the diffusion time and TM1. Equal T1 weighting at arbitrary diffusion times is realized by keeping the total mixing time TM1 + TM2 constant. The sequence was compared with conventional stimulated‐echo measurements of diffusion in a 2‐compartment phantom consisting of distilled water and paraffinum perliquidum. Additionally, in vivo DTI of the brain was carried out for 8 healthy volunteers with diffusion times ranging from 50 to 500 ms.ResultsDiffusion time dependence of the axial and radial diffusivity was detected in the brain. Both sequences resulted in almost identical diffusivities in white matter. In regions containing partial volumes of gray and white matter, a dependency on T1 weighting was observed.ConclusionIn accordance with previous studies, little variance of T1 values appeared to be present in healthy white matter. However, this is likely different in diseased tissue. Here, the proposed sequence can be effective in differentiating between diffusion time dependence and T1 weighting effects.
Changes in Physiology and Stress Responses of Pellet-Reared Largemouth Bass Fed Live-Forage Diets
Authors: Dinken Colin P , Keretz Kevin R , Schramm Harold L , Petrie-Hanson Lora , Wes Schilling M , Allen Peter J 
Published: October 2019

Abstract
Advanced-sized Largemouth Bass Micropterus salmoides to be used for stocking and experimentation can be efficiently reared on prepared feed in intensive culture conditions, but formulated diets containing high levels (≥20%) of dietary carbohydrates may lead to high liver and muscle lipid and high liver glycogen levels, which may affect survival and stress responses. Largemouth Bass were raised to a size of 240–344 mm TL on formulated diets and then were fed live forage (i.e., naturalization); the effects of naturalization on liver, blood, and muscle health indices and physiological stress measures were evaluated, and indices were compared with those of wild Largemouth Bass from three different reservoirs. Hepatosomatic index (HSI) decreased by week 1 of naturalization; liver glycogen decreased by week 2; liver lightness, yellowness, and steatosis decreased by week 4; and liver moisture and lipid concentration stabilized after 4 weeks. Plasma cortisol was higher by week 1 of naturalization than by week 6 and onward, and plasma pH decreased after 1 week. Muscle color showed changes by week 1 of naturalization, muscle collagen stabilized by week 4, and muscle lipids decreased more gradually compared to the liver. The magnitude of stress response in fish subjected to a 60-s chasing stressor was unaffected by naturalization. Among populations of wild fish, many liver, blood, and muscle metrics were similar, with the exception of liver yellowness, glycogen, and HSI; muscle redness, lipids, and moisture; and the viscerosomatic index. Therefore, after rearing on a high-carbohydrate, high-lipid diet (i.e., 20% carbohydrates; 16% lipids), 4–6 weeks of naturalization can improve liver health, with most liver parameters being similar to those found in populations of wild fish.
Impact of a Real‐World Lifestyle Intervention in an Entire Latin American City with More Than 50,000 People
Authors: Atalla Marcio , Pinto Ana Jessica , Mielke Gregore Iven , Benatti Fabiana Braga , Gualano Bruno 
Published: October 2019

ObjectiveThe aim of this study was to assess the impact of a real‐world citywide intervention on physical activity and eating habits in a Latin American city with more than 50,000 inhabitants.MethodsThis was a plausibility assessment of a real‐life intervention. A probabilistic sample (n = 1,424) from Jaguariuna (Sao Paulo, Brazil) was assessed before and after a 7‐month intervention aimed at increasing physical activity levels and improving eating habits at a city level. Primary outcomes were physical activity, sedentary behavior, and eating habits assessed by a valid telephone inquiry. The secondary outcome was body weight.ResultsThe proportion of individuals achieving the recommended intake of fruits and vegetables increased (18%; 95% CI: 2% to 36%; P = 0.031), whereas the number of individuals consuming soft drinks and exchanging main meals for snacks or junk food decreased (−35%; 95% CI: −45% to −22%; P < 0.001 and −16%; 95% CI: −29% to −1%; P = 0.037). The number of active individuals increased during leisure time (37%; 95% CI: 19% to 58%; P < 0.001), at work (17%; 95% CI: 4% to 32%; P = 0.009), and in the household (14%; 95% CI: 0% to 31%; P = 0.047). Body weight decreased among individuals with overweight or obesity.ConclusionsThis intervention promoted pronounced lifestyle changes (i.e., increased physical activity and healthier food choices) in the entire city, providing scientific‐based evidence on which to build effective public health policies in Latin America.
New cardo silylated poly(azomethine)s containing 9,9′‐diphenylfluorene units as materials with Brønsted acid‐dependent fluorescence
Authors: Hauyon René A , Garrido‐Gatica Gabriela , Sobarzo Patricio A , González‐Henríquez Carmen M , Tagle Luis H , Rodríguez‐González Fidel E , Jessop Ignacio A , Recabarren‐Gajardo Gonzalo , Tundidor‐Camba Alain , Terraza Claudio A 
Published: October 2019

AbstractAromatic poly(azomethine)s have been studied due to their attractive properties such as high thermal stability, semiconducting behavior and the ability to coordinate species with their imine units (CN). In this paper, the synthesis and characterization of two novel silylated poly(azomethine)s containing cardo units are reported. These materials were highly soluble in organic solvents such as chloroform and m‐cresol and were thermally stable, and PAzMC1 exhibited a high glass transition temperature value (287 °C), while that for PAzMC2 was not observed. UV–visible spectrophotometry revealed absorption bands related to the aromatic backbone of both PAzMCs, 300–285 nm in tetrahydrofuran and 310–301 nm in dimethylsulfoxide, and bands attributed to the conjugated imine unit at around 350 nm. In order to investigate the phenomenon of the emission of fluorescence promoted by dopant agents with regard to potential optoelectronic applications, the materials were doped with H2SO4 and their optical and electrochemical properties investigated. Thus, the absorption band of the imine group was suppressed due to the nitrogen atoms being protonated. Fluorescence spectroscopy analysis developed in dilute solutions of polymers showed no emission from the undoped polymers, whereas the acid‐doped species emitted fluorescence in the UV and violet regions (322 nm). Cyclic voltammetry measurements were carried out and HOMO–LUMO energies were estimated. This study provides a starting point for the development of new poly(azomethine)s with doping‐dependent emission. © 2019 Society of Chemical Industry
Structural diversity in the Mycobacteria DUF3349 superfamily
Authors: Buchko Garry W. , Abendroth Jan , Robinson John I. , Phan Isabelle Q. , Myler Peter J. , Edwards Thomas E. 
Published: October 2019

AbstractA protein superfamily with a “Domain of Unknown Function,”, DUF3349 (PF11829), is present predominately in Mycobacterium and Rhodococcus bacterial species suggesting that these proteins may have a biological function unique to these bacteria. We previously reported the inaugural structure of a DUF3349 superfamily member, Mycobacterium tuberculosis Rv0543c. Here, we report the structures determined for three additional DUF3349 proteins: Mycobacterium smegmatis MSMEG_1063 and MSMEG_1066 and Mycobacterium abscessus MAB_3403c. Like Rv0543c, the NMR solution structure of MSMEG_1063 revealed a monomeric five α‐helix bundle with a similar overall topology. Conversely, the crystal structure of MSMEG_1066 revealed a five α‐helix protein with a strikingly different topology and a tetrameric quaternary structure that was confirmed by size exclusion chromatography. The NMR solution structure of a fourth member of the DUF3349 superfamily, MAB_3403c, with 18 residues missing at the N‐terminus, revealed a monomeric α‐helical protein with a folding topology similar to the three C‐terminal helices in the protomer of the MSMEG_1066 tetramer. These structures, together with a GREMLIN‐based bioinformatics analysis of the DUF3349 primary amino acid sequences, suggest two subfamilies within the DUF3349 family. The division of the DUF3349 into two distinct subfamilies would have been lost if structure solution had stopped with the first structure in the DUF3349 family, highlighting the insights generated by solving multiple structures within a protein superfamily. Future studies will determine if the structural diversity at the tertiary and quaternary levels in the DUF3349 protein superfamily have functional roles in Mycobacteria and Rhodococcus species with potential implications for structure‐based drug discovery.
Diet–tissue discrimination factors (δ15N and δ13C values) for blood components in Magellanic (Spheniscus magellanicus) and southern rockhopper (Eudyptes chrysocome) penguins
Authors: Jenkins Edward , Gulka Julia , Yurkowski David J. , Davoren Gail K. , Gonzalez Lana 
Published: October 2019

RationaleAnalysis of the stable isotope ratios of carbon and nitrogen (δ13C and δ15N values) is increasingly being used to gain insight into predator trophic ecology, which requires accurate diet–tissue discrimination factors (DTDFs), or the isotopic difference between prey and predator. Accurate DTDFs must be calculated from predators consuming an isotopically constant diet over time in controlled feeding experiments, but these studies have received little attention to date, especially among seabird species.MethodsIn this study, aquarium‐housed Magellanic (Spheniscus magellanicus) and southern rockhopper (Eudyptes chrysocome) penguins were fed a single‐prey source diet (capelin Mallotus villosus) for eight weeks. Stable isotope ratios (δ13C and δ15N values) of penguin blood (cellular component and plasma) and capelin were measured using mass spectrometry and then used to calculate DTDFs for both components of penguin blood by comparison with prey values.ResultsThe DTDFs for plasma were −0.63 ± 0.49 (mean ± SD) and −0.27 ± 0.22 for δ13C values, and 2.60 ± 0.50 and 2.78 ± 0.22 for δ15N values for Magellanic and southern rockhopper penguins, respectively, while the DTDFs for the cellular component were 1.22 ± 0.03 and 1.26 ± 0.03 for δ13C values, and 2.54 ± 0.07 and 2.43 ± 0.17 for δ15N values.ConclusionsWe compare our DTDFs with published values from blood components of penguins and discuss the effects that lipid extraction, sample storage, and diet have on the DTDFs of penguin blood components. This study provides accurate DTDFs of blood components for two seabird species of conservation concern, and is one of the first to provide plasma DTDFs for penguins, which are underrepresented in the seabird literature.
Concentration‐dependent coulombic effects in travelling wave ion mobility spectrometry collision cross section calibration
Authors: Eldrid Charles , O'Connor Eloise , Thalassinos Konstantinos 
Published: October 2019

RationaleTravelling wave ion mobility spectrometry (TWIMS) is increasingly being used as a method for calculating the collision cross sections (CCSs) of protein ions. To calculate the CCS values of unknown ions, however, the TWIMS device needs to be calibrated using calibrant proteins of known CCS values. The effect of calibrant protein concentration on the accuracy of the resulting calibration curve has not been explicitly studied so far. We hypothesised that at high protein concentrations the ion density within the TWIMS device will be such that ions will experience space charge effects resulting in deviations, as well as broadening, of ion arrival time distributions (ATDs). Calibration curves using these altered ATDs would therefore result in incorrect CCS values being calculated for the protein ions of interest.MethodsThree protein CCS calibrants, avidin, bovine serum albumin and β‐lactgobulin, were prepared at different concentrations and used to calculate the CCS of a non‐calibrant protein. Data were collected on a Synapt G1 ion mobility mass spectrometer with a nano‐electrospray ionisation (nESI) source using capillaries prepared in house.ResultsIncreasing the concentration of CCS calibrants caused ATD broadening and shifted the ATD peak tops, leading to a significant increase in calculated CCS values.ConclusionsThe concentration of protein calibrants can directly affect the quality of the CCS calibration in TWIMS experiments.
The use of extracted‐ion chromatograms to quantify the composition of condensed tannin subunits
Authors: Giribaldi Julien , Besson Martin , Suc Lucas , Fulcrand Hélène , Mouls Laetitia 
Published: October 2019

RationaleThe analysis of tannins is currently usually done by liquid chromatography after the chemical depolymerization of tannins. However, one of the main limitations of this method is the difficulty in specifically detecting each constitutive tannin monomer in a complex matrix, as numerous compounds co‐elute with the monomers, thereby compromising the analysis.MethodsThe depolymerization of tannins under acidic conditions and in the presence of thioglycolic acid releases the various constitutive monomers, either as terminal units or as extension units. The tannin subunits were then quantified using extracted‐ion chromatogram (EIC) mass spectrometry, which required the determination of the ionization efficiency of the monomers. Thus, we used AgBF4‐assisted coupling for the hemisynthesis of the noncommercial epicatechin gallate dimer.ResultsThe EIC showed that the derivatives of the extension units were twice as ionized as the terminal units. Unlike the UV chromatograms, this new EIC‐based method is more specific and accurate because it is not impacted by the co‐elution phenomenon. This result, when added to the linearity obtained on a large range of the calibration curves, allowed for quantification of tannin subunits from EIC in complex mixtures with less pretreatment of the samples.ConclusionsDue to its specificity and sensitivity, this EIC‐based method represents a significant step toward improving the quantification of the tannin composition of samples. The results of this study should allow the oxidation markers to be quantified more accurately and taken into account, thereby providing a better indication of the actual tannin composition.