bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coordination Polymer Nanobamboos of {FexIn1−x}‐MIL‐88B: Induced Formation of a Virtual In‐MIL‐88B
Authors: Park Shin Ae , Lee Hee Jung , Cho Yea Jin , Choi Sora , Oh Moonhyun 
Published: April 2014

AbstractA precise fabrication of nanobamboo structures made from hybrid coordination polymers of the type {FexIn1−x}‐MIL‐88B is demonstrated. The compositions of the hybrid coordination polymer nanobamboos of {FexIn1−x}‐MIL‐88B (x=0.06, 0.19, or 0.75) are regulated by altering the amount of metal ions used in the reactions. Interestingly, the formation of a virtual In‐MIL‐88B (precise structure, {Fe0.06In0.94}‐MIL‐88B), which cannot be created in a typical reaction, is induced by the assistance of a Fe‐MIL‐88B structure. The a and c cell parameters of {Fe0.06In0.94}‐MIL‐88B are calculated at 10.95 and 19.86 Å, respectively. These values of {Fe0.06In0.94}‐MIL‐88B are larger than those of pure Fe‐MIL‐88B owing to the large ionic size of In3+ within the framework.
Anionic Bipyridyl Ligands for Applications in Metallasupramolecular Chemistry
Authors: Pascu Mirela , Marmier Mathieu , Schouwey Clément , Scopelliti Rosario , Holstein Julian J. , Bricogne Gérard , Severin Kay 
Published: April 2014

AbstractThe facile synthesis of anionic bipyridyl ligands with dinuclear clathrochelate cores is described. These metalloligands can be obtained in high yields by the reactions of M(ClO4)2(H2O)6 (M: Zn, Mn, or Co) with 4‐pyridylboronic acid and 2,6‐diformyl‐4‐methylphenol oxime or 2,6‐diformyl‐4‐tert‐butylphenol oxime, followed by deprotonation. The ligands are interesting building blocks for metallasupramolecular chemistry, as evidenced by the formation of a Pt‐based molecular square and four coordination polymers with 2D or 3D network structures. Competition experiments reveal that the utilization of anionic bipyridyl ligands can result in significantly more stable assemblies.
The Borohydride Oxidation Reaction on La–Ni‐Based Hydrogen‐Storage Alloys
Authors: Paschoalino Waldemir J. , Thompson Stephen J. , Russell Andrea E. , Ticianelli Edson A. 
Published: April 2014

AbstractThis work provides insights into the processes involved in the borohydride oxidation reaction (BOR) in alkaline media on metal hydride alloys formed by LaNi4.7Sn0.2Cu0.1 and LaNi4.78Al0.22 with and without deposited Pt, Pd, and Au. The results confirm the occurrence of hydrolysis of the borohydride ions when the materials are exposed to BH4− and a continuous hydriding of the alloys during BH4− oxidation measurements at low current densities. The activity for the direct BOR is low in both bare metal hydride alloys, but the rate of the BH4− hydrolysis and the hydrogen‐storage capacity are higher, while the rate of H diffusion is slower for bare LaNi4.78Al0.22. The addition of Pt and Pd to both alloys results in an increase of the BH4− hydrolysis, but the H2 formed is rapidly oxidized at the Pt‐modified catalysts. In the case of Au modification, a small increase in the BH4− hydrolysis is observed as compared to the bare alloys. The presence of Au and Pd also leads to a reduction of the rates of alloy hydriding/de‐hydriding.
Diabetes mellitus is associated with early chronic venous disorder of the lower extremities in Chinese patients with cardiometabolic risk factors
Authors: Zhong Jian , Chen Jing , Zhao Zhi‐gang , He Hong‐bo , Yan Zhen‐cheng , Liu Dao‐yan , Zhu Zhi‐ming , Ni Yin‐xing 
Published: April 2014

AbstractBackgroundMetabolic syndrome has received great attention because it poses a potential cardiovascular hazard, which increases the risk of lower extremity atherosclerosis. However, the relationship between the components of metabolic syndrome and the onset of chronic venous disorder of the lower extremities remains unexplained.MethodsThis study investigated the characteristics of cardiometabolic risk factors of early chronic venous disorder of the lower extremities in subjects with cardiometabolic risk. The characteristics of risk factors and diabetes‐related complications in diabetic patients with early chronic venous disorder of the lower extremities were also investigated. In addition, the association between early chronic venous disorder and atherosclerosis of the lower extremities was analysed. The study examined 782 subjects with cardiometabolic risk factors, including obesity, hypertension, diabetes mellitus and dyslipidaemia. Lower extremity venous function was measured by digital photoplethysmography.ResultsWomen had a higher prevalence of early chronic venous disorder than did men (p < 0.01). Male subjects with early chronic venous disorder had a higher systolic blood pressure than those with normal venous function (p < 0.01), and female subjects with early chronic venous disorder had a higher fasting plasma glucose level than did controls (p < 0.05). The prevalence of diabetes mellitus is also significantly higher in female patients with early chronic venous disorder (p = 0.000). Diabetic patients with early chronic venous disorder not only had higher fasting plasma glucose and total cholesterol levels but also had more serious macrovascular complications than the control group. The independent risk factors of early chronic venous disorder in female subjects with cardiometabolic risks were age and fasting plasma glucose in men it was only age Women face a two times greater risk than men. The independent risk factors of early chronic venous disorder in diabetic patients were age, gender, HbA1c and triglyceride levels Women had an almost 12 times greater risk of early chronic venous disorder than men. Among the diabetic patients, the prevalence of early chronic venous disorder did not differ by ankle‐brachial index.ConclusionFemale subjects with cardiometabolic risk factors or female diabetic patients face a greater risk of early chronic venous disorder than do male subjects. Diabetic patients with early chronic venous disorder had more serious macrovascular complications than did the controls, and the early venous function was found to be correlated with the blood glucose level and triglyceride status. Copyright © 2014 John Wiley & Sons, Ltd.
Hydrological feedbacks in northern peatlands
Authors: Waddington J. M. , Morris P. J. , Kettridge N. , Granath G. , Thompson D. K. , Moore P. A. 
Published: April 2014

AbstractNorthern peatlands provide important global and regional ecosystem services (carbon storage, water storage, and biodiversity). However, these ecosystems face increases in the severity, areal extent and frequency of climate‐mediated (e.g. wildfire and drought) and land‐use change (e.g. drainage, flooding and mining) disturbances that are placing the future security of these critical ecosystem services in doubt. Here, we provide the first detailed synthesis of autogenic hydrological feedbacks that operate within northern peatlands to regulate their response to changes in seasonal water deficit and varying disturbances. We review, synthesize and critique the current process‐based understanding and qualitatively assess the relative strengths of these feedbacks for different peatland types within different climate regions. We suggest that understanding the role of hydrological feedbacks in regulating changes in precipitation and temperature are essential for understanding the resistance, resilience and vulnerability of northern peatlands to a changing climate. Finally, we propose that these hydrological feedbacks also represent the foundation of developing an ecohydrological understanding of coupled hydrological, biogeochemical and ecological feedbacks. Copyright © 2014 John Wiley & Sons, Ltd.
Asymmetric Access to α‐Substituted Functional Aspartic Acid Derivatives by a [3+2] Strategy Employing a Chiral Dienophile
Authors: Ben Ayed Kawther , Beauchard Anne , Poisson Jean‐François , Py Sandrine , Laurent Mathieu Y. , Martel Arnaud , Ammar Houcine , Abid Souhir , Dujardin Gilles 
Published: April 2014

AbstractEnantiopure vinyl ethers of Stericol® underwent diastereoselective thermal 1,3 dipolar cycloadditions with N‐benzyl, N‐benzhydryl, and N‐PMB aspartate ester nitrones. Chemoselective N‐debenzylation of the resulting cycloadducts afforded diastereomerically and enantiomerically pure crystalline NH‐isoxazolidine, the absolute configuration of which was established by X‐ray crystallography. N‐Protection and N–O cleavage of this isoxazolidine gave enantioenriched quaternary aspartate derivatives bearing functionalized side chains.
Analysis of High‐Field Energy Harvesting using Ferroelectric Materials
Authors: Patel Satyanarayan , Chauhan Aditya , Vaish Rahul 
Published: April 2014

AbstractThe ferroelectric family of materials is employed in a wide variety of applications, ranging from simple sensors, transducers, and actuators to micro‐electromechanical systems. The ability of these materials to combine electrical and mechanical responses has led to the establishment of many energy‐harvesting and conversion systems. However, the low energy density coupled with high frequency requirements has prevented the successful commercialization of this technology. In this regards, a new approach is presented that is capable of enhanced electro‐mechanical energy conversion by utilizing the high‐field behavior of ferroelectric materials. A novel cycle has been recommended for continuous energy generation by using the proposed method. The cycle was simulated for the commercially available lead zirconate titanate (PZT) bulk ceramic and a maximum energy density of 526 kJ m−3 per cycle was obtained for a compressive stress of 0–400 MPa and an electric field of 0.2–2.0 kV mm−1. The energy density obtained by using the presented technique is several hundred times higher than the highest energy density previously reported.
Online clean‐up of volatile compounds in complex matrices for GC‐MS quantification: testing with fragranced consumer products
Authors: Debonneville Christian , Chaintreau Alain 
Published: April 2014

ABSTRACTThe quantification of volatile compounds in cosmetic products or raw materials remains problematic because of the complexity of the matrices. Two approaches were investigated on the basis of a full vaporization of analytes from a sample deposited on a cylinder of polydimethylsiloxane (PDMS) foam: (1) an internal standardization using the same calibration curve for all samples, which gives rise to unexplained peak magnifications that biases the determinations, and (2) a standard addition protocol. The latter was tested for the analysis of suspected allergens and allowed the quantification of all compounds except farnesol and Lyral®. A decision tree was proposed to ascertain peak identity and the validity of the regression curve. Using this strategy in the range of 50–100 mg/l, 91% of all individual results (except farnesol and Lyral®) in all matrices fell within a tolerance interval of ±25%. In addition, the use of disposable PDMS cylinders allowed 400 injections without polluting the injector or the column. Copyright © 2014 John Wiley & Sons, Ltd.
Roe‐type Riemann solvers for general hyperbolic systems
Authors: Castro Cristóbal E. , Toro Eleuterio F. 
Published: April 2014

SUMMARYWe present a Roe‐type weak formulation Riemann solver where the average coefficient matrix is computed numerically. The novelty of this approach is that it is general enough that can be applied to any hyperbolic system while retaining the accuracy of the original Roe solver. We show applications to the compressible Euler equations with general equation of state. An alternative version of the method uses directly the eigenvectors in the averaging process, simplifying the algorithm. These new solvers are applied in conservative and path‐conservative schemes with high‐order accuracy and on unstructured meshes. Copyright © 2014 John Wiley & Sons, Ltd.
MicroRNA‐155 in oral squamous cell carcinoma: Overexpression, localization, and prognostic potential
Authors: Shi Lin‐Jun , Zhang Chen‐Yang , Zhou Zeng‐Tong , Ma Jing‐Yuan , Liu Yang , Bao Zhe‐Xuan , Jiang Wei‐Wen 
Published: April 2014

ABSTRACTBackgroundOral squamous cell carcinoma (OSCC) is a common malignancy with poor prognosis. MicroRNAs (miRNAs) play an important role in cancer, but their role in OSCC is not clarified.MethodsWe performed miRNA microarray, quantitative reverse transcription polymerase chain reaction (qRT‐PCR), and fluorescence in situ hybridization (FISH) to examine miRNA expression in OSCC and paired adjacent cancer‐free mucosal (ACF) tissues.ResultsThirteen miRNAs, including miRNA‐155, were upregulated (>2‐fold) in OSCC against ACF. MiRNA‐155 was confirmed to have significantly higher expression in OSCC against ACF (paired‐samples t test; p = .041) and it was localized in the cancer nest, inflammatory area, and vascular endothelium of OSCC. High expression of miRNA‐155 in ACF tissue was an independent prognostic indicator for OSCC survival.ConclusionMiRNA‐155 was overexpressed in OSCC and it was located in the cancer nest, inflammatory area, and vascular endothelium of OSCC. High miRNA‐155 expression level in ACF may predict poor prognosis in patients with OSCC. © 2014 Wiley Periodicals, Inc. Head Neck 37: 970–976, 2015
Raman Spectroscopic Characterization of Polyselenophenes and Poly(3,4‐ethylenenedioxyselenophene)s
Authors: Ferrón Cristina Capel , Sheynin Yana , Li Mao , Patra Asit , Bendikov Michael , López Navarrete Juan T. , Hernández Victor , Ruiz Delgado M. Carmen 
Published: April 2014

AbstractHerein we present novel Raman spectroscopic studies carried out for polyselenophene (PSe), poly(3,4‐ethylenedioxyselenophene) (PEDOS), and alkyl‐substituted poly(alkyl‐3,4‐ethylenedioxyselenophene) (PEDOS‐Cn: n=2, 8, and 12) homologues. These spectroscopic data are combined with morphological and structural analysis techniques, such as AFM, and DFT simulations. An investigation into the extent of π‐conjugation in PSe is presented by comparing its spectral signatures with those of a homologous series of oligoselenophenes. Our experimental data suggest that π‐conjugation in the PSe backbone extends to more than six selenophene units. The incorporation of ethylenedioxy (EDO) groups in PEDOS results in a more complex spectrum and a downshift of the CC/CC stretching vibration (or effective conjugation coordinate (ECC) mode); this provides evidence for an improvement in the π‐conjugational properties along the PSe backbone upon EDO substitution. The dispersity of π‐conjugation lengths in different PEDOS samples obtained through different synthetic routes is evaluated as a function of different structural factors. Finally, we present experimental evidence that the insertion of alkyl chains into the EDO units slightly impacts on the π‐conjugational properties of the PEDOS backbone in the non‐annealed samples (with an improved π‐electron delocalization found in PEDOS‐C8), but moderately affects the degree of molecular order of polymer films upon thermal annealing.
Atmospheric background associated with severe lightning thunderstorms in Central Spain
Authors: Mora Manuel , Riesco Jesús , de Pablo Dávila F. , Rivas Soriano Luis 
Published: April 2014

ABSTRACTA study of electrically severe thunderstorms (>2000 cloud‐to‐ground flashes per day) in the Spanish territory of Castilla‐Leon (northern plateau of the Iberian Peninsula) has been performed using 11 years (2000–2010) of data. These episodes were classified according to average upper‐level synoptic patterns. Seven synoptic patterns emerged: shortwave and very shortwave troughs, three types of lows, cyclonic vortex and ridge. The moisture content at low levels and static instability were also considered. In general, all the episodes were associated with instability and moderate moisture (11 g kg−1 for the average mixing ratio at 925 hPa). The electrically severe thunderstorms associated with five synoptic patterns (shortwave and very shortwave troughs, and three types of lows) generated hail, strong winds, and intense precipitation. By contrast, the cyclonic vortex and ridge synoptic types were not associated with severe weather.
Rigid Polyimide Networks End‐Linked with Tri‐ and Tetra‐armed Crosslinkers
Authors: Yoshihara Naoki , Hosono Nobuhiko , Ohshima Ryota , Totani Kenro , Watanabe Toshiyuki 
Published: April 2014

Rigid polymer networks with aromatic polyimide (PI) backbones end‐linked with symmetric crosslinkers are designed. 1,3,5‐Tris(4‐aminophenyl)benzene (TAPB) and tetra(4‐aminophenyl)methane (TAPM) are used as the crosslinkers. Whereas TAPB has three reactive amines at planar threefold symmetric (C3) positions, TAPM has four amines at tetragonal (S4) positions. Poly(amide acid) (PAA) precursors are end‐linked with TAPB or TAPM to make PAA networks. The crosslinking reaction efficiencies and mechanical properties of the PAA gels are investigated by the sol fraction method and compressive stress–strain tests, respectively. The PAA gels are successively transformed to PI gels through chemical imidization treatments. From the swelling behavior, it is found that the PI gels have high void contents up to 70%.
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Synthesis of a new rhodamine‐containing block copolymer for highly selective and sensitive detection of Cu2+ and CN− ions in aqueous media
Authors: Banerjee Rakesh , Pal Deep Sankar , Dhara Dibakar 
Published: April 2014

AbstractDevelopment of new chemosensors that are selective and sensitive to Cu2+ and CN− ions, especially in aqueous media, is of tremendous importance. We report the synthesis of a new block copolymer that is capable of highly selective and sensitive detection of Cu2+ and CN− ions in aqueous media. Poly(t‐butylacrylate)‐block‐poly(3‐bromopropylacrylate) was prepared using the reversible addition–fragmentation chain transfer polymerization technique. This block copolymer was reacted with 2,4‐dihydroxybenzaldehyde followed by reaction with rhodamine B hydrazide for successful incorporation of the desired rhodamine units into the block copolymer structure. Cu2+‐induced opening of the spirolactam ring of the rhodamine units resulted in rapid and easily noticeable colour change, thus enabling a highly selective detection of Cu2+ ions in aqueous media for concentrations as low as 2 µmol L−1. We further demonstrate that this Cu2+ bound polymer complex can further act as a selective and sensitive sensing platform for CN− in aqueous media with concentrations <1 µmol L−1 (0.06 ppm). Moreover, the polymer can also be used to remove Cu2+ from aqueous media. © 2014 Society of Chemical Industry
Inter‐hospital variation in the frequency of sinus surgery in children with cystic fibrosis
Authors: Virgin Frank W. , Huang Lin , Roberson David W. , Sawicki Gregory S. 
Published: April 2014

SummaryBackgroundChronic rhinosinusitis and nasal polyposis are common conditions in cystic fibrosis (CF). Approximately 2–3% of pediatric CF patients per year have sinus disease requiring surgery. The purpose of this study was to evaluate the variation of sinus surgery rates in pediatric CF patients across multiple US pediatric hospitals.MethodsThe Pediatric Health Information System (PHIS) compiles inpatient administrative data from 42 pediatric hospitals. We conducted a retrospective analysis of PHIS for the period January 1, 2008 to January 1, 2011 to evaluate frequency of sinus surgery at each hospital. We identified CF patients and sinus surgery during inpatient encounters using ICD‐9 codes. Demographic data and data for each hospital on hospital size, number of pediatric otolaryngologists, average FEV1, and percentage of patients meeting minimum care guidelines were collected. Twenty‐nine hospitals were included in analysis using mixed‐effects logistic regression models for occurrence of sinus surgery.ResultsWe identified 5,194 CF patients, accounting for 18,788 unique encounters among 29 hospitals. 880 patients underwent 1,397 sinus operations. Total number of CF patients at each institution ranged from 39 to 364 and total number of sinus surgeries ranged from 4 to 205, over the 3‐year period. Variation in the rate of sinus surgery with hospital encounter was observed (1–24%). Hospital‐average lung function (P = 0.56), number of otolaryngologists (P = 0.65) were not found to be predictors of sinus surgery. The size of the CF center (P = 0.01), hospital size (P = 0.05), and age at admission (P ≤ 0.0001) were associated with an increased frequency of sinus surgery. However, with multivariable analysis, only size of the CF center and age of admission remained statistically significant predictors of surgery with admission.ConclusionsThere is large variation in the incidence of sinus surgery for CF in 29 of the largest freestanding pediatric hospitals. This study highlights remarkable variation in clinical practice and underscores the need for further research into the indications and benefits of sinus surgery in pediatric patients with CF. Pediatr Pulmonol. 2015; 50:231–235. © 2014 Wiley Periodicals, Inc.
Importance of Reservoir Tributaries to Spawning of Migratory Fish in the Upper Paraná River
Authors: da Silva P. S. , Makrakis M. C. , Miranda L. E. , Makrakis S. , Assumpção L. , Paula S. , Dias J. H. P. , Marques H. 
Published: April 2014

AbstractRegulation of rivers by dams transforms previously lotic reaches above the dam into lentic ones and limits or prevents longitudinal connectivity, which impairs access to suitable habitats for the reproduction of many migratory fish species. Frequently, unregulated tributaries can provide important habitat heterogeneity to a regulated river and may mitigate the influence of impoundments on the mainstem river. We evaluated the importance of tributaries to spawning of migratory fish species over three spawning seasons, by comparing several abiotic conditions and larval fish distributions in four rivers that are tributaries to an impounded reach of the Upper Paraná River, Brazil. Our study confirmed reproduction of at least 8 long‐distance migrators, likely nine, out of a total of 19 occurring in the Upper Paraná River. Total larval densities and percentage species composition differed among tributaries, but the differences were not consistent among spawning seasons and unexpectedly were not strongly related to annual differences in temperature and hydrology. We hypothesize that under present conditions, densities of larvae of migratory species may be better related to efficiency of fish passage facilities than to temperature and hydrology. Our study indicates that adult fish are finding suitable habitat for spawning in tributaries, fish eggs are developing into larvae, and larvae are finding suitable rearing space in lagoons adjacent to the tributaries. Our findings also suggest the need for establishment of protected areas in unregulated and lightly regulated tributaries to preserve essential spawning and nursery habitats. Copyright © 2014 John Wiley & Sons, Ltd.
Continuous sequential boundaries for vaccine safety surveillance
Authors: Li Rongxia , Stewart Brock , Weintraub Eric , McNeil Michael M. 
Published: April 2014

AbstractVarious recently developed sequential methods have been used to detect signals for post‐marketing surveillance in drug and vaccine safety. Among these, the maximized sequential probability ratio test (MaxSPRT) has been used to detect elevated risks of adverse events following vaccination using large healthcare databases. However, a limitation of MaxSPRT is that it only provides a time‐invariant flat boundary. In this study, we propose the use of time‐varying boundaries for controlling how type I error is distributed throughout the surveillance period. This is especially useful in two scenarios: (i) when we desire generally larger sample sizes before a signal is generated, for example, when early adopters are not representative of the larger population; and (ii) when it is desired for a signal to be generated as early as possible, for example, when the adverse event is considered rare but serious. We consider four specific time‐varying boundaries (which we call critical value functions), and we study their statistical power and average time to signal detection. The methodology we present here can be viewed as a generalization or flexible extension of MaxSPRT. Published 2014. This article is a US Government work and is in the public domain in the USA.