bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Active and Selective Catalysis of Copper Diphosphine Complexes for the Transformation of Carbon Dioxide into Silyl Formate
Authors: Motokura Ken , Kashiwame Daiki , Takahashi Naoki , Miyaji Akimitsu , Baba Toshihide 
Published: June 2013

AbstractCopper diphosphine complexes have been found to be highly active and selective homogeneous catalysts for the hydrosilylation of CO2. The structure of the phosphine ligands strongly affects their catalytic activity. Turnover number (TON) reaches 70 000 after 24 hours with 1,2‐bis(diisopropylphosphino)benzene as a ligand under 1 atmosphere of CO2. 1H and 13C NMR spectra, carried out under the reaction conditions, showed the reaction mechanism through insertion of CO2 into CuH to afford Cu/formate species.
Application of Functionalized N,S‐Ketene Acetals–Microwave‐Assisted Three‐Component Domino Reaction for Rapid Direct Access to Imidazo[1,2‐a]pyridines
Authors: Li Ming , Li Tengfei , Zhao Kelong , Wang Mingda , Wen Lirong 
Published: June 2013

AbstractImidazo[1,2‐a]pyridines have been successfully synthesized in moderate to good yields via a tandem three‐component reaction of ethyl 2‐(3‐oxo‐3‐arylpropanethioamido)acetates with aromatic aldehydes and malononitrile by means of microwave irradiation using DABCO as the catalyst. The advantages of this method including high chemo‐ and regioselectivity make this new strategy highly attractive.
A Long‐Wavelength Fluorescent Probe for Saccharides Based on Boronic‐Acid Receptor
Authors: Bai Hongyan , Sun Qian , Tian Haiyu , Qian Junhong , Zhang Lingyi , Zhang Weibing 
Published: June 2013

AbstractA single boronic acid‐based fluorescent probe (compound CSP) for saccharides was designed and synthesized. The probe, with an α,β‐unsaturated ketone conjugated into the coumarin fluorophore, was synthesized by 4 steps from the commercial material 4‐diethylamino salicylaldehyde. The electron push‐pull effect is enhanced with the N,N‐diethyl amino as the electron donor and the carbonyl as the electron acceptor. Both the absorption (463 nm) and emission (616 nm) maxima of CSP are in the visible wavelength region with a Stokes shift of about 150 nm, which ensures CSP a potential probe for biological application. Under near physiological conditions, significant fluorescence enhancement of CSP was observed upon the addition of some saccharides, namely, D‐sorbitol, D‐fructose, D‐glucose, D‐mannose and D‐galactose. The probe showed relatively high sensitivity towards D‐fructose and D‐sorbitol, and their detection limits were 0.05 mmol/L and 0.1 mmol/L, respectively.
Self‐Biasing Photoelectrochemical Cell for Spontaneous Overall Water Splitting under Visible‐Light Illumination
Authors: Chen Quanpeng , Li Jinhua , Li Xuejin , Huang Ke , Zhou Baoxue , Shangguan Wenfeng 
Published: June 2013

AbstractA self‐biasing photoelectrochemical (PEC) cell that could work for spontaneous overall water splitting in a neutral solution was established based on the mismatched Fermi levels between the photoelectrodes. A Pt‐catalyst‐decorated crystalline silicon photovoltaic cell (Pt/PVC) was prepared and employed as an effective photocathode. This was coupled with a poly(ethylene glycol)‐directed WO3/W photoanode prepared by a hydrothermal process. Both of the photoelectrodes showed a response to visible light. The WO3/W photoanode had a positively located valence band edge, the energy level of which was enough for water oxidation, and the Pt/PVC photocathode possessed a negatively located conduction band edge, which was capable of water reduction. More importantly, the Fermi level of the WO3/W photoanode was more positive than that of the Pt/PVC photocathode because of the p–n junction of the PVC that decoupled the band bending and enlarged the photovoltage. Under visible‐light irradiation, the WO3/W photoanode provided a negative bias for the Pt/PVC photocathode, and the Pt/PVC photocathode provided a positive bias for the WO3/W photoanode. An interior bias was generated that could relax the strict criteria of overall water splitting by cooperatively separating the hole–electron pairs at both photoelectrodes. In this system, the short‐circuit current and the open‐circuit voltage increased with increasing light intensity (AM 1.5 illumination) to reach 121 μA cm−2 and 0.541 V, respectively, at a light intensity of 100 mW cm−2. Such a combination provides a promising method for the fabrication of self‐driven devices for solar‐energy storage.
Deployment control of wireless multihop‐relay mobile robots based on voronoi partition
Authors: Imaizumi Takaaki , Murakami Hiroyuki , Uchimura Yutaka 
Published: June 2013

SummaryThis paper describes a new method for the deployment of wireless relay nodes. When using rescue robots in a building or underground city, radio signals are attenuated significantly, and therefore, multihop extension involving wireless communication relays is required. The goal of this research is to deploy wireless relay nodes to maintain connectivity between the base station and the leader robot that explores around the front line. To move the relay robot autonomously, a distributed algorithm is required.The proposed method is suitable when it is applied for wireless relay purposes. In this method, a virtual force drives a node to the centroid of Voronoi neighbors so that the connectivity of wireless communication is maintained. The proposed method is evaluated by conducting numerical simulations and experiments. In the simulation, one or two leader robots are assumed. In the experiment, a mobile robot equipped with omni‐wheels is used. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(4): 42–51, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22413
The Quest for Cobalt‐Free Alkyd Paint Driers
Authors: de Boer Johannes W. , Wesenhagen Philana V. , Wenker Erica C. M. , Maaijen Karin , Gol Franjo , Gibbs Hugh , Hage Ronald 
Published: June 2013

AbstractPaint formulations, based either on organic solvents or on water, often contain alkyd resins that depend on catalysts for their oxidative curing. Cobalt carboxylates are the most widely used to date, but the use of these compounds is under pressure because classification as carcinogens under the REACh system is probable, and as a consequence there is great interest in the development of alternative driers to cobalt‐based ones. A variety of manganese and iron carboxylates have been studied as paint drying catalysts in the last two decades, but these often show drawbacks with respect to activity, level of application, colour of the paint drier or cost in use. More recently, several reports on active manganese and iron paint driers containing polydentate ligands have been published. In particular, one iron‐based catalyst, identified originally for stain bleaching in laundry cleaning, shows good paint drying activity at very low dosage levels, outperforming cobalt carboxylates in a wide range of applications.
Metal‐Free Oxidative Carbon‐Heteroatom Bond Formation Through C–H Bond Functionalization
Authors: Samanta Rajarshi , Matcha Kiran , Antonchick Andrey P. 
Published: June 2013

AbstractDirect methods of carbon‐heteroatom bond formation through functionalization of non‐reactive C–H bonds represent an attractive approach to the synthesis of interesting products. This review focuses on the development of metal‐free coupling methods for unactivated compounds under oxidative reaction conditions. The utility of these methods in syntheses of desired products and the mechanisms of their formation are discussed with numerous examples.
Synthesis of Highly Functionalized Enantiopure Halocyclopropanes Derived from Carbohydrates
Authors: Rodríguez‐Solla Humberto , Concellón Carmen , del Amo Vicente , Díaz‐Pardo Ainhoa , Blanco Elena G. , García‐Granda Santiago , Díaz M. Rosario , Llavona Ricardo , Soengas Raquel G. 
Published: June 2013

AbstractA chromium‐mediated synthesis of enantiopure sugar‐based halocyclopropanecarboxamides is reported. This reaction can be stereospecifically carried out on (E)‐ or (Z)‐α,β‐unsaturated amides and takes place with the formation of a new C‐Hal stereogenic center, which is generated with total stereoselectivity. Synthetic applications of the obtained halocyclopropanecarboxamides are also reported. The structure of the halocyclopropanes and derivatives were established by X‐ray analysis. A mechanism to explain these transformations is proposed.
An Aerobic and Very Fast Pd/C‐Catalyzed Ligand‐Free and Aqueous Suzuki Reaction Under Mild Conditions
Authors: Liu Chun , Rao Xiaofeng , Zhang Yixia , Li Xinmin , Qiu Jieshan , Jin Zilin 
Published: June 2013

AbstractAn aerobic, ligand‐free Suzuki reaction catalyzed by Pd/C in aqueous media has been developed. This method is a very simple, efficient and mild protocol for the cross‐coupling of aryl bromides with arylboronic acids, and the reactions proceeded smoothly in excellent yields within short reaction times. Control experiments demonstrated that the Pd/C‐catalyzed Suzuki reaction was much quicker when performed in air or oxygen than in nitrogen. Furthermore, this protocol could be used for the synthesis of fluorinated liquid‐crystalline compounds. The Pd/C catalyst could be recovered and recycled efficiently at least ten times without significant loss of catalytic activity.
Two‐dimensional modelling of large wood transport during flash floods
Authors: Ruiz Villanueva Virginia , Bladé Castellet Ernest , Díez‐Herrero Andrés , Bodoque José M. , Sánchez‐Juny Martí 
Published: June 2013

ABSTRACTLarge woody material (LWM) transported by rivers may be entrapped at critical stream geometry configurations (e.g. bridges) and therefore dramatically increase the destructive power of floods. This was the case in a Spanish mountain river where a flood event with a high degree of LWM transport took place in 1997. The aim of this study was to simulate a bridge clogging process and reconstruct the wood deposit patterns, modelling individual pieces of wood moving with the water flow and interacting among them and with the bridge. A two‐dimensional numerical model was developed to simulate the transport of LWM and its effect on hydrodynamics. Different scenarios for the wood transport rate allowed us to study the influence of inlet boundary conditions on bridge clogging. For the studied event, the scenario which best reproduced the bridge clogging effect and flood characteristics was one in which 60% of the total wood entered before the peak discharge. This dropped to 30% at the peak itself, and finally fell to 10% during the recession curve. In addition, the accumulation patterns of LWM along the reach were computed and compared with post‐event field photographs, showing that the model succeeded in predicting the deposition patterns of wood and those areas prone to form wood jams. Copyright © 2013 John Wiley & Sons, Ltd.
Alleviation of chromium toxicity by hydrogen sulfide in barley
Authors: Ali Shafaqat , Farooq Muhammad Ahsan , Hussain Sabir , Yasmeen Tahira , Abbasi G.H. , Zhang Guoping 
Published: June 2013

Abstract

A hydroponic experiment was carried out to examine the effect of hydrogen sulfide (H2S) in alleviating chromium (Cr) stress in barley. A 2-factorial design with 6 replications was selected, including 3 levels of NaHS (0 μM, 100 μM, and 200 μM) and 2 levels of Cr (0 μM and 100 μM) as treatments. The results showed that NaHS addition enhances plant growth and photosynthesis slightly compared with the control. Moreover, NaHS alleviated the inhibition in plant growth and photosynthesis by Cr stress. Higher levels of NaHS exhibited more pronounced effects in reducing Cr concentrations in roots, shoots, and leaves. Ultrastructural examination of plant cells supported the facts by indication of visible alleviation of cell disorders in both root and leaf with exogenous application of NaHS. An increased number of plastoglobuli, disintegration, and disappearance of thylakoid membranes and starch granules were visualized inside the chloroplast of Cr-stressed plants. Starch accumulation in the chloroplasts was also noticed in the Cr-treated cells, with the effect being much less in Cr + NaHS-treated plants. Hence, it is concluded that H2S produced from NaHS can improve plant tolerance under Cr stress. Environ Toxicol Chem 2013;32:2234–2239. © 2013 SETAC
Imposex and novel mechanisms of reproductive failure induced by tributyltin (TBT) in the freshwater snail Pomacea canaliculata
Authors: Giraud-Billoud Maximiliano , Vega Israel A. , Wuilloud Rodolfo G. , Clément María E. , Castro-Vazquez Alfredo 
Published: June 2013

Abstract

The effects of tributyltin (TBT) on mortality and reproduction were studied in the invasive snail Pomacea canaliculata. The nominal median lethal concentration (LC50) was 9 µg TBT/L, after 28 d. The nominal no-observed effect on lethality concentration (NOECL) was 6 µg TBT/L after the same period. Male–female couples and females that had been group-mated but were isolated from males during the experiment (isolated females) were exposed (for 28 d) to either 0 µg/L or 6 µg/L of TBT (nominal NOECL-exposed). Copulation and oviposition frequencies, egg clutch mass, and percentage of egg fertility were recorded. Gonads (both sexes) and the seminal receptacle (females) were studied histologically at the end of the experiment. A significant decrease in copulation frequency was observed in mated-exposed females. Exposure also decreased oviposition frequency of mated-exposed and isolated-exposed females, but only the latter reached significance. No differences in either egg clutch mass or percentage of fertility were observed at first oviposition, but both parameters were drastically reduced in subsequent egg clutches of exposed females. No histological alterations were observed in gonads of TBT-exposed animals; however, sperm storage in the seminal receptacle was drastically decreased in exposed females. Imposex but no oviductal obstruction was observed in all exposed females. It is concluded that TBT induces reproductive failure in P. canaliculata by decreasing copulation frequency and by severely affecting sperm storage by the female. Environ Toxicol Chem 2013;32:2365–2371. © 2013 SETAC
PER‐PERIOD CO‐PAYMENTS AND THE DEMAND FOR HEALTH CARE: EVIDENCE FROM SURVEY AND CLAIMS DATA
Authors: Farbmacher Helmut , Winter Joachim 
Published: June 2013

ABSTRACTWhen health insurance reforms involve non‐linear price schedules tied to payment periods (for example, fees levied by quarter or year), the empirical analysis of its effects has to take the within‐period time structure of incentives into account. The analysis is further complicated when demand data are obtained from a survey in which the reporting period does not coincide with the payment period. We illustrate these issues using as an example a health care reform in Germany that imposed a per‐quarter fee of €10 for doctor visits and additionally set an out‐of‐pocket maximum. This co‐payment structure results in an effective ‘spot’ price for a doctor visit that decreases over time within each payment period. Taking this variation into account, we find a substantial reform effect—especially so for young adults. Overall, the number of doctor visits decreased by around 9% in the young population. The probability of visiting a physician in any given quarter decreased by around 4 to 8 percentage points. Copyright © 2013 John Wiley & Sons, Ltd.
MEDICARE SKILLED NURSING FACILITY REIMBURSEMENT AND UPCODING
Authors: Bowblis John R. , Brunt Christopher S. 
Published: June 2013

ABSTRACTPost‐acute care provided by skilled nursing facilities (SNFs) is reimbursed by Medicare under a prospective payment system using resource utilization groups (RUGs) that adjust payment intensity on the basis of predefined ranges of weekly therapy minutes provided and the functionality of the patient. Individual RUGs account for differences in the intensity of care provided, but there exists significant regional variation in the payments SNFs receive from Medicare due to the use of geographic adjustment factors. This paper is the first to use this geographic variation in the generosity of Medicare reimbursement to empirically test if SNFs respond to payment differences between RUG categories. The results are highly suggestive that SNFs upcode patients by providing additional therapy minutes to increase revenue, whereas we find no evidence of upcoding related to patient functionality scores. Simulating how different payment differentials affect RUG selection, we predict that reducing the financial incentive to upcode could result in significant savings to Medicare. Copyright © 2013 John Wiley & Sons, Ltd.
Association Between the Metabolome and Low Bone Mineral Density in Taiwanese Women Determined by 1H NMR Spectroscopy
Authors: You Ying-Shu , Lin Ching-Yu , Liang Hao-Jan , Lee Shen-Hung , Tsai Keh-Sung , Chiou Jeng-Min , Chen Yen-Ching , Tsao Chwen-Keng , Chen Jen-Hau 
Published: June 2013

ABSTRACT Osteoporosis is related to the alteration of specific circulating metabolites. However, previous studies on only a few metabolites inadequately explain the pathogenesis of this complex syndrome. To date, no study has related the metabolome to bone mineral density (BMD), which would provide an overview of metabolism status and may be useful in clinical practice. This cross-sectional study involved 601 healthy Taiwanese women aged 40 to 55 years recruited from MJ Health Management Institution between 2009 and 2010. Participants were classified according to high (2nd tertile plus 3rd tertile) and low (1st tertile) BMD groups. The plasma metabolome was evaluated by proton nuclear magnetic resonance spectroscopy (1H NMR). Principal components analysis (PCA), partial least-squares discriminant analysis (PLS-DA), and logistic regression analysis were used to assess the association between the metabolome and BMD. The high and low BMD groups could be differentiated by PLS-DA but not PCA in postmenopausal women (Q2 = 0.05, ppermutation = 0.04). Among postmenopausal women, elevated glutamine was significantly associated with low BMD (adjusted odds ratio [AOR] = 5.10); meanwhile, elevated lactate (AOR = 0.55), acetone (AOR = 0.51), lipids (AOR = 0.04), and very low-density lipoprotein (AOR = 0.49) protected against low BMD. To the best of our knowledge, this study is the first to identify a group of metabolites for characterizing low BMD in postmenopausal women using a 1H NMR–based metabolomic approach. The metabolic profile may be useful for predicting the risk of osteoporosis in postmenopausal women at an early age. © 2014 American Society for Bone and Mineral Research.
The effect of carbon source on extracellular polymeric substances production and its influence on sludge floc properties
Authors: Wang Hongwu , Deng Huanhuan , Ma Luming , Ge Liyun 
Published: June 2013

AbstractBACKGROUNDExtracellular polymeric substances (EPSs) play an essential role in the performance of biological wastewater treatment. It is necessary to understand the correlation between EPSs and the carbon sources and sludge‐retention time (SRT) of the activated‐sludge process to gain efficient operational strategies.RESULTSPolysaccharides (PSs) and proteins (PNs) were the main constituents in EPSs. The percentage of PSs and PNs in the loosely bound (LB‐) EPSs and tightly bound (TB‐) EPSs were 18–90% and 18–85%, respectively. The PS/PN ratios in the LB‐EPS and TB‐EPS were in the range 0.38–2.50 and 0.30–2.34, respectively. The contents of LB‐EPSs and TB‐EPSs were both slightly higher in sludge samples cultivated by starch than by those cultivated by glucose. Compared with the sludge samples grown in glucose, the PSs content of the LB‐EPS was higher than in other samples, whereas the PNs content was lower in the LB‐EPS from sludge flocs grown in starch than those grown in glucose. PSs yield of TB‐EPSs was almost equal in the two carbon sources, whereas PNs yield was slightly higher in TB‐EPSs from samples cultured with glucose than with starch.CONCLUSIONLaboratory studies were performed to evaluate the effect of carbon sources on EPSs production. The total contents of LB‐EPSs and TB‐EPSs were affected by the kinds of carbon sources. PS and PN in LB‐EPSs and TB‐EPSs were both dependent on carbon sources. In addition, confocal laser scanning microscopy (CLSM) observations indicated that microbial cells were cross‐linked by EPS, forming a polymeric network with pores and channels. © 2013 Society of Chemical Industry
Laser (U‐Th)/He thermochronology of detrital zircons as a tool for studying surface processes in modern catchments
Authors: Tripathy‐Lang Alka , Hodges Kip V. , Monteleone Brian D. , van Soest Matthijs C. 
Published: June 2013

AbstractDetrital mineral thermochronology of modern sediments is a valuable tool for interrogating landscape evolution. Detrital zircon (U‐Th)/He thermochronology is of particular interest because zircons are durable and withstand transport in glacial and fluvial systems far better than, for example, apatite. However, because of the time‐intensive nature of conventional zircon (U‐Th)/He thermochronology, most previous studies of this kind have relied on data for a few tens of grains, even though conventional wisdom holds that a substantially larger number is necessary for a robust characterization of the population of cooling ages in a sample. Here, we introduce a microanalytical approach to detrital zircon (U‐Th)/He thermochronology that addresses many factors that can complicate the interpretation of conventional zircon (U‐Th)/He data, particularly with respect to alpha ejection and injection and U + Th zoning. In addition, this technique permits the effective dating of naturally abraded and broken grains, and, therefore, lessens the potential for sampling bias. We apply both conventional and laser microprobe techniques to a detrital sample from the Ladakh Range in the northwestern Indian Himalaya, showing that the two yield very similar principal modes of apparent ages. However, the laser microprobe data yield a broader spectrum of ages than that of the conventional data set, which we interpret to be caused by bias related to the selection requirements for zircons used for conventional dating. This method thus provides a time‐efficient route to obtaining a higher‐resolution distribution of dates from a single sample, which will, in turn, yield higher‐fidelity constraints regarding catchment‐wide erosion rates for surface process studies.
Acting professional: An exploration of culturally bounded norms against nonwork role referencing
Authors: Uhlmann Eric Luis , Heaphy Emily , Ashford Susan J. , Zhu Luke [Lei] , Sanchez‐Burks Jeffrey 
Published: June 2013

SummaryThis article presents three studies examining how cross‐cultural variation in assumptions about the appropriateness of referencing nonwork roles while in work settings creates consequential impressions that affect professional outcomes. Study 1 reveals a perceived norm limiting the referencing of nonwork roles at work and provides evidence that it is a U.S. norm by showing that awareness of it varies as a function of tenure living in the United States. Studies 2 and 3 examine the implications of the norm for evaluations of job candidates. Study 2 finds that U.S. but not Indian participants negatively evaluate job candidates who endorse nonwork role referencing as a strategy to create rapport and shows that this cultural difference is largest among participants most familiar with norms of professionalism, those with prior recruiting experience. Study 3 finds that corporate job recruiters from the United States negatively evaluate candidates who endorse nonwork role referencing as a means of building rapport with a potential business partner. This research underlines the importance of navigating initial interactions in culturally appropriate ways to facilitate the development of longer‐term collaborations and negotiation success. Copyright © 2013 John Wiley & Sons, Ltd.