bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermoset Shape‐Memory Polyurethane with Intrinsic Plasticity Enabled by Transcarbamoylation
Authors: Zheng Ning , Fang Zizheng , Zou Weike , Zhao Qian , Xie Tao 
Published: June 2016

AbstractThermoset polymers are known for their superior thermomechanical properties, but the chemical crosslinking typically leads to intractability. This is reflected in the great differences between thermoset and thermoplastic shape‐memory polymers; the former exhibit a robust shape memory but are not capable of redefining the permanent shape. Contrary to current knowledge, we reveal here that a classical thermoset shape‐memory polyurethane is readily capable of permanent reshaping (plasticity) after a topological network rearrangement that is induced by transcarbamoylation. By employing the Jianzhi technique (also known as kirigami), unexpected shape‐shifting versatility was observed for this otherwise classical material. As the essential carbamate moiety in polyurethanes is one of the most common polymer building units, we anticipate that our finding will have significant benefits beyond shape shifting.
Highly Stable, Amide‐Bridged Autoinducing Peptide Analogues that Strongly Inhibit the AgrC Quorum Sensing Receptor in Staphylococcus aureus
Authors: Tal‐Gan Yftah , Ivancic Monika , Cornilescu Gabriel , Yang Tian , Blackwell Helen E. 
Published: June 2016

AbstractBlocking quorum sensing (QS) pathways has attracted considerable interest as an approach to suppress virulence in bacterial pathogens. Toward this goal, we recently developed analogues of a native autoinducing peptide (AIP‐III) signal that can inhibit AgrC‐type QS receptors and attenuate virulence phenotypes in Staphylococcus aureus. Application of these compounds is limited, however, as they contain hydrolytically unstable thioester linkages and have only low aqueous solubilities. Herein, we report amide‐linked AIP analogues with greatly enhanced hydrolytic stabilities and solubilities relative to our prior analogues, whilst maintaining strong potencies as AgrC receptor inhibitors in S. aureus. These compounds represent powerful tools for the study of QS.
Influence of a rigid polystyrene block on the free volume and ionic conductivity of a gel polymer electrolyte based on poly(methyl methacrylate)‐block‐polystyrene
Authors: Guan Xinghua , Chen Fang , Li Zhiguang , Zhou Hualong , Ma Xiaoyan 
Published: June 2016

ABSTRACTDiblock copolymers poly(methyl methacrylate)‐block‐polystyrene with three different molar ratios [poly(methyl methacrylate)/polystyrene (PS) = 1:1, 1:1.5, and 1:1.8] were synthesized by atom transfer radical polymerization and used as a polymer matrix for gel polymer electrolytes (GPEs). The positron annihilation lifetime spectroscopy was applied to determine the free‐volume behaviors of different GPEs, respectively. We illustrated that a proper PS ratio may led to the formation of a high fraction of free volume, and the influence of the PS ratio on the free‐volume fraction was caused by the different morphologies of the GPEs because of the different packing densities of the PS rigid block. The ionic conductivity was correlated with the free volume in the GPE through the study of the ionic conductivity dependence on the temperature; this followed the Vogel–Tamman–Fulcher equation. Moreover, an ionic conductive model was proposed, in which variations of the free‐volume behavior provide different ionic‐conducting abilities. Thermogravimetric analysis indicated that GPEs based on different block copolymers exhibited high liquid‐electrolyte preservation properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43901.
Impact of the first 5 years of a national abdominal aortic aneurysm screening programme
Authors: Jacomelli J , Summers L , Stevenson A , Lees T , Earnshaw J J 
Published: June 2016

Abstract

Background
The Abdominal Aortic Aneurysm (AAA) Screening Programme was introduced by the National Health Service (NHS) in England to reduce the rate of death from ruptured AAA in men. The programme commenced in 2009 and was implemented completely across the country in April 2013. The aim was to review the first 5 years of the programme, looking specifically at compliance and early outcome.

Methods
Men aged 65 years were invited for a single abdominal ultrasound scan. Data were entered into a bespoke database (AAA SMaRT). This was a planned analysis after the first 5 years of the programme.

Results
The summation analysis involved the first 700 000 men screened, and the first 1000 men with a large AAA referred for possible treatment. The prevalence of AAA (aortic diameter larger than 2·9 cm) in 65-year-old men was 1·34 per cent. Mean uptake was 78·1 per cent, but varied from 61·7 to 85·8 per cent across the country. Based on the Index of Multiple Deprivation, uptake was 65·1 per cent in the most deprived versus 84·1 per cent in the least deprived areas. Of the first 1000 men referred for possible treatment of a large AAA (greater than 5·4 cm), the false-positive rate was 3·2 per cent. Some 870 men underwent a planned AAA intervention (non-intervention rate 9·2 per cent), with seven deaths (perioperative mortality rate 0·8 per cent).

Conclusion
The processes in the NHS AAA Screening Programme are effective in detecting and treating men with AAA.
The Structure of LiuC, a 3‐Hydroxy‐3‐Methylglutaconyl CoA Dehydratase Involved in Isovaleryl‐CoA Biosynthesis in Myxococcus xanthus, Reveals Insights into Specificity and Catalysis
Authors: Bock Tobias , Reichelt Joachim , Müller Rolf , Blankenfeldt Wulf 
Published: June 2016

AbstractMyxobacteria are able to produce the important metabolite isovaleryl coenzyme A by a route other than leucine degradation. The first step into this pathway is mediated by LiuC, a member of the 3‐methylglutaconyl CoA hydratases (MGCH). Here we present crystal structures refined to 2.05 and 1.1 Å of LiuC in the apo form and bound to coenzyme A, respectively. By using simulated annealing we modeled the enzyme substrate complex and identified residues potentially involved in substrate binding, specificity, and catalysis. The dehydration of 3‐hydroxy‐3‐methylglutaconyl CoA to 3‐methylglutaconyl CoA catalyzed by LiuC involves Glu112 and Glu132 and likely employs the typical crotonase acid‐base mechanism. In this, Tyr231 and Arg69 are key players in positioning the substrate to enable catalysis. Surprisingly, LiuC shows higher sequence and structural similarity to human MGCH than to bacterial forms, although they convert the same substrate. This study provides structural insights into the alternative isovaleryl coenzyme A biosynthesis pathway and might open a path for biofuel research, as isovaleryl‐CoA is a source for isobutene, a precursor for renewable fuels and chemicals.
Assisted care as a baseline patient risk characteristic affecting the outcome of transcatheter aortic valve insertion
Authors: Traynor Megan M. , Greason Kevin L. , Nkomo Vuyisile T. , Pochettino Alberto , Holmes David R. , Rihal Charanjit S. , Reeder Guy S. , Bresnahan John F. , Mathew Verghese 
Published: June 2016

BackgroundObjective measures of frailty have not been well defined as risk factors for a poor outcome after transcatheter aortic valve insertion. We hypothesized that assisted care as a baseline patient characteristic was a simple objective measure of frailty. We reviewed our experience to assess for an association between assisted care and outcome of operation.MethodsWe retrospectively reviewed the records of 597 patients operated with transcatheter aortic valve insertion from November 2008 through July 2015. The study cohort included patients with a dichotomous baseline characteristic of receiving assisted care (AC group, n = 60, 10.1%) or not receiving assisted care (NC group, n = 537, 89.9%). The endpoints of the study were operative stroke/death and 1‐year survival.ResultsThe age of the patients was 80.6 ± 9.0 years, male sex was present in 349 (58.5%), and STS predicted risk of mortality was 9.2 ± 6.2%. Alternate access was used in 26 (43.3%) patients in the AC care group and in 220 (41.0%) in the NC group (P = 0.724). Operative stroke/death occurred in 4 (6.7%) patients in the AC group and in 25 (4.7%) in the NC group (P = 0.492). Mortality at 1 year in the AC group was 14.8 ± 5.2% and in the NC group was 12.9 ± 1.7%; (P = 0. 250).ConclusionsAssisted care as a baseline patient characteristic does not result in increased operative stroke/death or 1‐year mortality in patients following transcatheter aortic valve insertion. Assisted care should not by itself preclude operation. © 2016 Wiley Periodicals, Inc.
Purification of Ginkgo biloba Extract by Antisolvent Recrystallization
Authors: Zu Yuan Gang , Wang Lingling , Zhao Xiuhua , Li Yuanyuan , Wu Weiwei , Zu Chang , Huang Yannian , Wu Mingfang , Feng Ziqi 
Published: June 2016

AbstractThe content of flavonoids in Gingko biloba extract (GBE) could be increased by antisolvent recrystallization (ASR) using ethanol as solvent and hexane as antisolvent. By means of the single‐factor method, the effect of main factors on the content of flavonoids in purified GBE was investigated. Under optimal conditions, the content of flavonoids and ginkgo terpene lactones in purified GBE could be significantly enhanced. In addition, the content of total ginkgolic acid in purified GBE was reduced. The morphologies of raw and purified GBE were characterized by scanning electron microscopy. It was found that the particle size of purified GBE was much smaller than that of raw GBE. At the same time, the saturated solubility could be improved by more than four times.
Quasi‐Block Copolymers Based on a General Polymeric Chain Stopper
Authors: Sanguramath Rajashekharayya A. , Nealey Paul F. , Shenhar Roy 
Published: June 2016

AbstractQuasi‐block copolymers (q‐BCPs) are block copolymers consisting of conventional and supramolecular blocks, in which the conventional block is end‐terminated by a functionality that interacts with the supramolecular monomer (a “chain stopper” functionality). A new design of q‐BCPs based on a general polymeric chain stopper, which consists of polystyrene end‐terminated with a sulfonate group (PS‐SO3Li), is described. Through viscosity measurements and a detailed diffusion‐ordered NMR spectroscopy study, it is shown that PS‐SO3Li can effectively cap two types of model supramolecular monomers to form q‐BCPs in solution. Furthermore, differential scanning calorimetry data and structural characterization of thin films by scanning force microscopy suggests the existence of the q‐BCP architecture in the melt. The new design considerably simplifies the synthesis of polymeric chain stoppers; thus promoting the utilization of q‐BCPs as smart, nanostructured materials.
A Pd‐Catalyzed Synthesis of Functionalized Piperidines
Authors: Allen Benjamin D. W. , Connolly Matthew J. , Harrity Joseph P. A. 
Published: June 2016

AbstractA readily available cyclic carbamate 1 functions as a general precursor to a range of functionalized piperidine products via a new Pd‐catalyzed annulation strategy. An asymmetric catalytic variant provides a rapid and efficient means to access these heterocycles with high to excellent levels of enantiocontrol. Finally, these richly functionalized compounds are amenable to further chemoselective elaboration.
Contributions of prestrains, hyperelasticity, and muscle fiber activation on mitral valve systolic performance
Authors: Prot Victorien , Skallerud Bjorn 
Published: June 2016

SummaryThe present study addresses the contributions of prestrains and muscle fiber activation to the global response of the mitral valve during systole. A finite element model of a porcine mitral valve is created using anatomical measurements and 3D echocardiographic recordings. The passive behavior of the leaflets is modeled using a transversely isotropic hyperelastic constitutive model, and we assume orthotropic muscle activations in the anterior leaflet. A simple approach to incorporate prestrains in the mitral valve apparatus is used by expanding the mitral annulus before applying the ventricular pressure to the mitral leaflets. Several finite element analyses are run with or without muscle activation and with or without prestrains. The analysis results are compared at peak systole with the echocardiograpic recordings. The case where prestrains and activation are accounted for simultaneously is the most efficient to approach the physiological flat shape of the closed valve observed in the echocardiograpic measurements. These results suggest that the active components present in the mitral leaflets and the presence of prestrains contribute to the physiological deformations of the mitral valve at peak systole and that material models based on in vitro mechanical testing are not sufficient for numerical studies of the mitral apparatus. Copyright © 2016 John Wiley & Sons, Ltd.
Lithium Vanadium Phosphate/Carbon Nanofiber Films as Selfstanding, Binderfree, and Flexible Cathodes for Lithium‐Ion Batteries
Authors: Pi Zhi‐chao , Jing Mao‐xiang , Li Jing‐quan , Zhai Hong‐ai , Chen Li‐li , Yao Shan‐shan , Shen Xiang‐qian , Xi Xiao‐ming , Xiao Ke‐song 
Published: June 2016

AbstractFlexible lithium vanadium phosphate/carbon nanofiber (i.e., Li3V2(PO4)3/C) were fabricated by an electrospinning process combined with hot‐pressed sintering, and are used in lithium‐ion batteries as selfstanding, binderfree and flexible cathodes. The microstructure and crystalline phase of the as‐prepared films are characterized by scanning electron microscopy, transmission electron microscopy, and X‐ray diffractometry. The electrochemical properties of the Li3V2(PO4)3/C nanofiber films were analyzed by cyclic voltammetry and galvanostatic charge/discharge tests. When the nanofiber precursor was sintered at 850 °C for 20 h, the resulting film displays high flexibility and crystallinity. This selfstanding Li3V2(PO4)3/C film exhibits a superior rate performance even at 20 C and good cycle ability, with a retention capacity of 112 mAh g−1 at a current density of 1 C after 1000 cycles and 71 mAh g−1 at 5 C after 800 cycles. These features are attributed to the special composite structure formed by the Li3V2(PO4)3 and the carbon support, and the 3D long‐range conductive networks.
Interlaboratory evaluation of the assessment of arsenic bioaccumulation from field collected sediments using Hexagenia spp
Authors: Watson-Leung Trudy , Oke Moustapha , McElroy Mike , Stuart Marilyne , Rendas Martina , Raby Melanie , Mahon Kim 
Published: June 2016

Abstract

Standardized bioaccumulation testing of aquatic organisms is essential to understanding the impact of historical contamination on the quality of water and sediment. A standardized 28-d laboratory bioaccumulation method with a freshwater burrowing mayfly, Hexagenia spp., has been developed and internally validated by the Ontario Ministry of the Environment and Climate Change (MOECC). An interlaboratory comparison was conducted to assess the precision of this method. Field-collected sediment contaminated with arsenic was chosen for the present study. Control and test sediments were subsampled and sent to 6 laboratories to perform the bioaccumulation test. One laboratory failed to meet the control survival criterion of ≥80%. When results of this laboratory are removed from the arsenic accumulation assessment, the mean interlaboratory variability (expressed as coefficient of variation) of the arsenic whole-body concentration is reduced from 44% to 24% in the test sediment–exposed Hexagenia spp. There was no significant interlaboratory difference between the Hexagenia spp. arsenic accumulations. While improved culturing and organism holding guidance may increase laboratory success, the MOECC Hexagenia spp. bioaccumulation test method has tight biological method precision when the control survival criterion is met. Environ Toxicol Chem 2016;35:2448–2455. © 2016 SETAC
Prototype filter design for FBMC systems via evolutionary PSO algorithm in highly doubly dispersive channels
Authors: Tabatabaee S.M.J. Asgari , Zamiri‐Jafarian H. 
Published: June 2016

AbstractThis paper proposes a new prototype filter design method based on the time‐frequency constellation for filter bank multicarrier (FBMC) systems in highly doubly dispersive channels. Maximal spectral efficiency, complex orthogonality and a well‐localised pulse shaping in time and frequency domains are three criteria in the prototype filter design. Satisfying these criteria simultaneously is a challenging issue in the FBMC system design. In order to meet these criteria as much as possible, we consider an FBMC system in which the complex‐valued data symbols are transmitted via a selected time‐frequency constellation with maximal spectral efficiency. Based on the selected constellation and channel statistic properties, the prototype filter is designed by maximising a new utility function called signal to weighted interference ratio (SWIR), which is defined according to the channel time and frequency dispersions. Because the SWIR is a nonlinear utility function, its maximisation is not straightforward. In this paper, for prototype filter design, a reliable, robust and fast converging algorithm called evolutionary cooperatively coevolving particle swarm optimisation is used to maximise the SWIR. The FBMC system, which uses the proposed prototype filter design method, can be combined with the MIMO techniques efficiently because of its capability of sending complex‐valued symbols. Simulation results show that the performance and bandwidth efficiency of the proposed method are superior to those of other techniques, for both cases of single antenna and multiple antennas, in highly doubly dispersive channels. Copyright © 2016 John Wiley & Sons, Ltd.
Effect of chronic somatic diseases on the course of late‐life depression
Authors: Hegeman Johanna M. , van Fenema Esther M. , Comijs Hannie C. , Kok Rob M. , van der Mast Roos C. , de Waal Margot W.M. 
Published: June 2016

ObjectiveTo examine the influence of specific chronic somatic diseases and overall somatic diseases burden on the course of depression in older persons.MethodsThis was a prospective cohort study with a 2‐year follow‐up. Participants were depressed persons (n = 285) from the Netherlands Study of Depression in Older Persons. The presence of chronic somatic diseases was based on self‐report. Diagnosis of depression was assessed with the Composite International Diagnostic Interview, and severity of depression was measured with the Inventory of Depressive Symptomatology Self‐report.ResultsCardiovascular diseases (odds ratio [OR] = 1.67, 95% confidence interval [CI] = 1.02–2.72, p = 0.041), musculoskeletal diseases (OR = 1.71, 95% CI = 1.04–2.80, p = 0.034), and the number of chronic somatic diseases (OR = 1.37, 95% CI = 1.16–1.63, p < 0.001) were associated with having a depressive disorder at 2‐year follow‐up. Furthermore, chronic non‐specific lung diseases, cardiovascular diseases, musculoskeletal diseases, cancer, or cumulative somatic disease burden were associated with a chronic course of depression.ConclusionsSomatic disease burden is associated with a poor course of late‐life depression. The course of late‐life depression is particularly unfavorable in the presence of chronic non‐specific lung diseases, cardiovascular diseases, musculoskeletal diseases, and cancer. Copyright © 2016 John Wiley & Sons, Ltd.
Dynamic single gold nanoparticle visualization by clinical intracoronary optical coherence tomography
Authors: Hu Jie , Rivero Fernando , Torres Rio Aguilar , Loro Ramírez Héctor , Rodríguez Emma Martín , Alfonso Fernando , García Solé José , Jaque Daniel 
Published: June 2016

The potential use of Gold Nanoparticles (GNPs) as contrast agents for clinical intracoronary frequency domain Optical Coherence Tomography (OCT) is here explored. The OCT contrast enhancement caused by GNPs of different sizes and morphologies has been systematically investigated and correlated with their optical properties. Among the different GNPs commercially available with plasmon resonances close to the operating wavelength of intracoronary OCT (1.3 µm), Gold Nanoshells (GNSs) have provided the best OCT contrast due to their largest scattering cross section at this wavelength. Clinical intracoronary OCT catheters are here demonstrated to be capable of three dimensional visualization and real‐time tracking of individual GNSs. Results here included open an avenue to novel application of intravascular clinical OCT in combination with GNPs, such as real time evaluation of intravascular obstructions or pressure gradients.
magnified image
Association between resource utilization and patient satisfaction at a tertiary care medical center
Authors: Biondi Eric A. , Hall Matthew , Leonard Michael S. , Pirraglia Paul A. , Alverson Brian K. 
Published: June 2016

BACKGROUNDThe Centers for Medicare and Medicaid Services has emphasized patient satisfaction as a means by which hospitals should be compared and as a component of financial reimbursement. We sought to identify whether resource utilization is associated with patient satisfaction ratings.DESIGNThis was a retrospective, cohort study over a 27‐month period from January 2012 to April 2014 of adult respondents (n = 10,007) to the Hospital Consumer Assessment of Healthcare Providers and Systems survey at a tertiary care medical center. For each returned survey, we developed a resource intensity score related to the corresponding hospitalization. We calculated a raw satisfaction rating (RSR) for each returned survey. Multivariable logistic regression was used to determine the association between resource intensity and top decile RSRs, using those with the lowest resource intensity as the reference group.RESULTSAdjusting for age, gender, insurance payer, severity of illness, and clinical service, patients in higher resource intensity groups were more likely to assign top decile RSRs than the lowest resource intensity group (“moderate” [adjusted odds ratio {aOR}: 1.42, 95% confidence interval {CI}: 1.11‐1.83], “major” [aOR: 1.56, 95% CI: 1.22‐2.01], and “extreme” [aOR: 2.29, 95% CI: 1.8‐2.92]).CONCLUSIONSResource utilization may be positively associated with patient satisfaction. These data suggest that hospitals with higher per‐patient expenditures may receive higher ratings, which could result in hospitals with higher per‐patient resource utilization appearing more attractive to healthcare consumers. Journal of Hospital Medicine 2016;11:785–791. © 2016 Society of Hospital Medicine
Effect of hexyl substituent groups on photophysical and electrochemical properties of the poly[(9,9‐Dioctyluorene)−2,7‐diyl‐alt‐(4,7‐bis (3‐Hexylthien‐5‐Yl)−2,1,3‐Benzothiadiazole)−2′,2″‐diyl]
Authors: da Silva Daniel J. , Takimoto Herick G. , dos Santos Karine C. C. Weber , Garcia Jarem R. , Balogh Debora T. , Wang Shu Hui 
Published: June 2016

ABSTRACTThe effect of the presence of hexyl group in thiophene on the photophysical and electrochemical properties of poly[(9,9‐dioctyluorene)−2,7‐diyl‐alt‐(4,7‐bis(3‐hexylthien‐5‐yl)−2,1,3‐benzothiadiazole)−2′,2″‐diyl] (F8TBT) is investigated. The copolymers present electron donor–acceptor architecture and are synthesized by Suzuki coupling reaction. The UV/Vis spectra show absorption maximum in the wavelength range of blue and orange, which are associated with different segments of the polymer backbone. Addition of hexyl substituent groups has a positive effect on the molar absorptivity and increases the emission and absorption intensities due to fluorene and thiophene‐benzothiadiazole‐thiophene (TBT) units, although an increment in the bandgap is observed. Cyclic voltammetry study of the polymer films reveal irreversible reduction and oxidation processes of the TBT units in the polymer chain and the HOMO and LUMO energy levels suggest ambipolar character for the polymers, while the electrochemical bandgaps are consistent with the absorbance measurements. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 1975–1982