bluuebunny/crossref_metadata_2025_split huggingface dataset:
Poly(ethylene glycol)‐containing cationic hydrogels with lipophilic character
Authors: Dutta Sujan , Dey Debabrata , Dhara Dibakar 
Published: September 2013

ABSTRACTNot much effort has been focused towards the development of hydrogels that swell in nonpolar solvents. We have synthesized a new set of polyelectrolyte hydrogels and demonstrated their ability to absorb a less‐polar or nonpolar organic solvent, as well as their ability to resist gel‐collapse in a predominantly nonpolar medium. The hydrogels were prepared by free radical polymerization of different molar ratios of poly(ethylene glycol) methyl ether acrylate and (3‐(methacryloylamino)propyl)‐trimethyl ammonium chloride as comonomers in an aqueous medium. Their swelling behavior in organic solvents was studied by varying the dielectric constant of the swelling medium including mixed‐solvent systems. Besides a high degree of swelling (up to 200 times) in polar solvents, some of the hydrogels also exhibited moderate swelling (up to 15 times) in less‐polar organic solvents. Hydrogels samples with high cationic content showed drastic change in swelling extent in some of the mixed‐solvent systems. It was also interesting to note that the retention of significant swelling in dimethyl sulphoxide–toluene mixture with even 90% toluene content for some compositions. These polyelectrolyte hydrogels with improved lipophilicity opens up greater opportunities for the development of even superior soft materials through proper structural optimizations that would successfully function for a wider range of solvents. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39873.
Adaptive Parameter Estimation for an Energy Model of Belt Conveyor with DC Motor
Authors: Shen Yanjun , Xia Xiaohua 
Published: September 2013

ABSTRACTIn practice, design parameters of a belt conveyor likely drift away from their design values by maintenance, readjustment, retrofit, abrasion, and circumstance change. For the purpose of energy optimization, these parameters should be estimated through experiments. In this paper, a new energy model of a DC motor driven belt conveyor is presented. Then, based on an adaptive observer, a parameter estimation algorithm is derived. In addition, under a persistent excitation condition, the convergence of the parameters to the desired values can also be concluded. Compared with the existing methods, our methods can be implemented by measuring only the feed rate of the belt conveyor and the angular velocity of the rotor of the DC motor.
Novel mutations in ADAMTSL2 gene underlying geleophysic dysplasia in families from United Arab Emirates
Authors: Ben‐Salem Salma , Hertecant Jozef , Al‐Shamsi Aisha M. , Ali Bassam R. , Al‐Gazali Lihadh 
Published: September 2013

BACKGROUNDGeleophysic dysplasia (GD) is an autosomal recessive disorder characterized by short stature, brachydactyly, stiff joints, thick skin, and cardiac valvular abnormalities that are often responsible for early death. Mutations in ADAMTSL2 and FBN1 genes have been shown to cause GD due to the dysregulation of transforming growth factor‐β signaling pathways. Small numbers of mutations in ADAMTSL2 have been reported so far in patients with GD type 1 (GD1).METHODSIn this study, we clinically evaluated two children from two consanguineous Arab families living in the United Arab Emirates with GD1. In addition we have sequenced all the coding exons of ADAMTSL2 gene using Sanger sequencing.RESULTSThe two patients exhibited most of the typical features of this rare bone dysplasia. Molecular analysis of the ADAMTSL2 gene revealed two novel homozygous missense mutations (c.938T>C, p.M313T and c.499G>A, p.D167N). The mutations segregated well in the studied families with the parents being heterozygous. In addition, bioinformatics analyses showed that these mutations are affecting conserved amino acids residues and thus strongly support their pathogenicity.CONCLUSIONWe describe the clinical phenotypes of two patients with GD1 that are caused by two novel homozygous missense mutations in the ADAMTSL2 gene. Birth Defects Research (Part A), 97:764–769, 2013. © 2013 Wiley Periodicals, Inc.
Simultaneous determination of three purines in Alysicarpus vaginalis (L.) DC. by hollow fiber‐based liquid‐phase microextraction combined with high‐performance liquid chromatography
Authors: Liu Hongjiao , Lei Ming , Liang Xiao , Jiang Zhen , Guo Xingjie 
Published: September 2013

ABSTRACTIn this paper, a three‐phase hollow fiber liquid‐phase microextraction (HF‐LPME) method combined with high‐performance liquid chromatography (HPLC) was developed for the determination of hypoxanthine (HX), xanthine (Xan) and adenine (A) and then for the first time successfully applied to the analysis of HX, Xan and A in Alysicarpus vaginalis (L.) DC. medicinal materials. Different factors affecting the HF‐LPME procedure were investigated and optimized. Under optimal extraction conditions (1‐octanol as organic solvent, pH of the donor and acceptor phase 10.0 and 3.5, respectively, extraction time 40 min, stirring rate 800 rpm and salt addition 10%, w/v), HX, Xan and A could be determined within the test ranges with a good correlation coefficient (r2 > 0.9992). The limit of detection for HX, Xan and A was 153, 173 and 97 ng/mL, respectively, and the intra‐ and inter‐day relative standard deviations were no more than 9.8%. The content of HX, Xan and A in Alysicarpus vaginalis (L.) DC. medicinal materials was 120.40, 18.37 and 62.75 µg/g, respectively. This procedure afforded a convenient, sensitive, accurate and inexpensive method with a high extraction efficiency for determination of HX, Xan and A. Copyright © 2013 John Wiley & Sons, Ltd.
A Unique Amino Transfer Mechanism for Constructing the β‐Amino Fatty Acid Starter Unit in the Biosynthesis of the Macrolactam Antibiotic Cremimycin
Authors: Amagai Keita , Takaku Ryoma , Kudo Fumitaka , Eguchi Tadashi 
Published: September 2013

AbstractCremimycin is a 19‐membered macrolactam glycoside antibiotic based on three distinctive substructures: 1) a β‐amino fatty acid starter moiety, 2) a bicyclic macrolactam ring, and 3) a cymarose unit. To elucidate the biosynthetic machineries responsible for these three structures, the cremimycin biosynthetic gene cluster was identified. The cmi gene cluster consists of 33 open reading frames encoding eight polyketide synthases, six deoxysugar biosynthetic enzymes, and a characteristic group of five β‐amino‐acid‐transfer enzymes. Involvement of the gene cluster in cremimycin production was confirmed by a gene knockout experiment. Further, a feeding experiment demonstrated that 3‐aminononanoate is a direct precursor of cremimycin. Two characteristic enzymes of the cremimycin‐type biosynthesis were functionally characterized in vitro. The results showed that a putative thioesterase homologue, CmiS1, catalyzes the Michael addition of glycine to the β‐position of a non‐2‐enoic acid thioester, followed by hydrolysis of the thioester to give N‐carboxymethyl‐3‐aminononanoate. Subsequently, the resultant amino acid was oxidized by a putative FAD‐dependent glycine oxidase homologue, CmiS2, to produce 3‐aminononanoate and glyoxylate. This represents a unique amino transfer mechanism for β‐amino acid biosynthesis.
MnCu/cordierite monolith used for catalytic combustion of Volatile Organic Compounds
Authors: Aguero F. N. , Morales M. R. , Duran F. G. , Barbero B. P. , Cadús L. E. 
Published: September 2013

AbstractA MnCu‐mixed oxide catalyst supported on a cordierite monolith was synthesized. The catalyst showed very good stability and high homogeneity and presented an excellent catalytic activity in the combustion of ethyl acetate, n‐hexane, and its mixture. The total conversion temperature of the mixture was determined by the temperature at which the most difficult molecule was oxidized.
Improved Interfacial Electron Transfer in Modified Bilirubin Oxidase Biocathodes
Authors: Lopez Ryan J. , Babanova Sofia , Ulyanova Yevgenia , Singhal Sameer , Atanassov Plamen 
Published: September 2013

AbstractThe reducing inhibition of interfacial electron transfer and the resulting impact on the catalytic current of bilirubin oxidase (BOx) biocathodes is explored. Polymer‐coated multi‐wall carbon nanotubes (MWNTs) are modified with tethering and orientating agents to provide stable immobilization and efficient enzyme orientation. 1‐pyrenebutanoic acid, succinimidyl ester (PBSE) is used as a cross‐linker. A BOx natural substrate, bilirubin, and its artificial analogues are explored as orientating agents. It is established that bilirubin/PBSE‐modified BOx cathodes show approximately 0.4‐ and 3.2‐fold increases in the current density compared to cathodes modified separately with either PBSE or bilirubin, respectively. In subsequent experiments, the incorporation of PBSE and 2,5‐dimethyl‐1‐phenyl‐1H‐pyrrole‐3‐carbaldehyde, a functional analogue of bilirubin, into the MWNT matrix results in a further 2–2.5‐fold increase in the generated current density compared to the hybrid bilirubin/PBSE‐modified cathode, which is, therefore, 20 times higher than the unmodified BOx cathode. This significant enhancement in the performance of the cathode is attributed to the concomitant covalent attachment and proper orientation of BOx, which leads to improved enzyme/electrode interactions.
Towards Highly Stable Storage of Sodium Ions: A Porous Na3V2(PO4)3/C Cathode Material for Sodium‐Ion Batteries
Authors: Shen Wei , Wang Cong , Liu Haimei , Yang Wensheng 
Published: September 2013

AbstractA porous Na3V2(PO4)3 cathode material coated uniformly with a layer of approximately 6 nm carbon has been synthesized by the sol–gel method combined with a freeze‐drying process. The special porous morphology and structure significantly increases the specific surface area of the material, which greatly enlarges the contact area between the electrode and electrolyte, and consequently supplies more active sites for sodium ions. When employed as a cathode material of sodium‐ion batteries, this porous Na3V2(PO4)3/C exhibits excellent rate performance and cycling stability; for instance, it shows quite a flat potential plateau at 3.4 V in the potential window of 2.7–4.0 V versus Na+/Na and delivers an initial capacity as high as 118.9 and 98.0 mA h g−1 at current rates of 0.05 and 0.5 C, respectively, and after 50 cycles, a good capacity retention of 92.7 and 93.6 % are maintained. Moreover, even when the discharge current density is increased to 5 C (590 mA g−1), an initial capacity of 97.6 mA h g−1 can still be achieved, and an exciting capacity retention of 88.6 % is obtained after 100 cycles. The good cycle performance, excellent rate capability, and moreover, the low cost of Na3V2(PO4)3/C suggest that this material is a promising cathode for large‐scale sodium‐ion rechargeable batteries.
Improved Synthesis of Capuramycin and Its Analogues
Authors: Wang Yong , Siricilla Shajila , Aleiwi Bilal A. , Kurosu Michio 
Published: September 2013

AbstractCapuramycin and its congeners are considered to be important lead molecules for the development of a new drug for multidrug‐resistant (MDR) Mycobacterium tuberculosis infections. Extensive structure–activity relationship studies of capuramycin to improve the efficacy have been limited because of difficulties in selectively chemically modifying the desired position(s) of the natural product with biologically interesting functional groups. We have developed efficient syntheses of capuramycin and its analogues by using new protecting groups, derived from the chiral (chloro‐4‐methoxyphenyl)(chlorophenyl)methanols, for the uridine ureido nitrogen and primary alcohol. The chiral nonracemic (2,6‐dichloro‐4‐methoxyphenyl)(2,4‐dichlorophenyl)methanol derivative is a useful reagent to resolve rac‐3‐amino‐1,3‐dihydro‐5‐phenyl‐2H‐1,4‐benzodiazepin‐2‐one, the (S)‐configuration isomer of which plays a significant role in improving the mycobactericidal activity of capuramycin.
The Enantioselective Pharmacokinetics Metabolism of Diniconazole in Quail (Coturnix coturnixs japonica)
Authors: Chen Jin Hui , Wang Hui Li , Guo Bao Yuan , Xu Peng , Li Jian Zhong 
Published: September 2013

ABSTRACTThe pharmacokinetics of diniconazole enantiomers in quail (Coturnix coturnix japonica) were investigated by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). Quails were exposed to racemic diniconazole in capsule by oral at dose of 10 mg/kg (body weight). The maximal concentrations observed in blood, heart, liver, and kidney were 3.18, 11.35, 12.32, 15.03 µg/g for S‐diniconazole, and 1.13, 3.70, 6.00, 2.60 µg/g for R‐diniconazole. The elimination of enantiomers all met the one‐compartment model in blood, heart, liver, and kidney well. The elimination half‐lives (T1/2) of S‐diniconazole were 2.87, 3.85, 5.29, and 4.42 h in blood, heart, liver, and kidney, respectively; the T1/2 of R‐diniconazole were 2.44, 3.42, 146.23, and 74.02 h in blood, heart, liver, and kidney, respectively. The enantiomer fractions (EFs) steadily increased from 0.50 to 0.92 in blood samples and 0.91 in heart samples. Meanwhile, the values increased to 0.70 and 0.80 in liver and kidney initially, and then decreased to 0.33 and 0.44 at the end of the experiment. Metabolism was examined as well and it was found that diniconazole was metabolized to 1, 2, 4‐triazole, (E)‐3‐(1H‐1, 2, 4‐triazol‐1‐yl) acrylaldehyde, (E, S)‐(R, S)‐4‐(2, 4‐dichlorophenyl)‐2, 2‐dimethyl‐5‐(1H‐1, 2, 4‐triazol‐1‐yl) pent‐4‐ene‐1, 3‐diol, (E)‐4‐(2, 4‐dichlorophenyl)‐3‐hydroxy‐2, 2‐dimethyl‐5‐(1H‐1, 2, 4‐triazol‐1‐yl) pent‐4‐enoic acid, and 1, 3‐dichlorobenzen in all samples of quail. Chirality 25:910–916, 2013. © 2013 Wiley Periodicals, Inc.
Shape‐Controlled Nanostructures in Heterogeneous Catalysis
Authors: Zaera Francisco 
Published: September 2013

AbstractNanotechnologies have provided new methods for the preparation of nanomaterials with well‐defined sizes and shapes, and many of those procedures have been recently implemented for applications in heterogeneous catalysis. The control of nanoparticle shape in particular offers the promise of a better definition of catalytic activity and selectivity through the optimization of the structure of the catalytic active site. This extension of new nanoparticle synthetic procedures to catalysis is in its early stages, but has shown some promising leads already. Here, we survey the major issues associated with this nanotechnology–catalysis synergy. First, we discuss new possibilities associated with distinguishing between the effects originating from nanoparticle size versus those originating from nanoparticle shape. Next, we survey the information available to date on the use of well‐shaped metal and non‐metal nanoparticles as active phases to control the surface atom ensembles that define the catalytic site in different catalytic applications. We follow with a brief review of the use of well‐defined porous materials for the control of the shape of the space around that catalytic site. A specific example is provided to illustrate how new selective catalysts based on shape‐defined nanoparticles can be designed from first principles by using fundamental mechanistic information on the reaction of interest obtained from surface‐science experiments and quantum‐mechanics calculations. Finally, we conclude with some thoughts on the state of the field in terms of the advances already made, the future potentials, and the possible limitations to be overcome.
Comparing operational definitions of DSM‐5 anorexia nervosa for research contexts
Authors: Brown Tiffany A. , Holland Lauren A. , Keel Pamela K. 
Published: September 2013

ABSTRACTObjectiveDSM‐5 anorexia nervosa (AN) criteria include several changes that increase reliance on clinical judgment. However, research contexts require operational definitions that can be applied reliably and that demonstrate validity. The present study evaluated different operational definitions for DSM‐5 AN.MethodDSM‐5 AN criteria were applied to diagnostic interview data from 364 women varying two features: threshold for determining low weight for Criterion A (body mass index [BMI] <17.0 kg/m2 vs. <18.5 kg/m2) and explicit endorsement of weight phobia (Criterion B explicit vs. inferred). Resulting groups of individuals with DSM‐5 AN were compared on estimated frequency. In addition, AN groups were compared to non‐eating disorder controls and individuals with an other specified feeding or eating disorder (OSFED) on external validators.ResultsAll operational DSM‐5 definitions produced higher lifetime frequency estimates than reported for DSM‐IV AN, with a particularly large increase associated with the broadest definition. All definitions produced significant differences in comparison to controls on external validators that were associated with medium to large effect sizes. Only definitions that required a lower weight threshold or explicit endorsement of weight phobia demonstrated significant differences compared to OSFED on external validators, and these were of small effect size. The specific combination of BMI <18.5 kg/m2 with inferred weight phobia exhibited few meaningful distinctions from the OSFED group.DiscussionTo balance inclusivity, syndromal reliability, and validity, an operational definition for DSM‐5 AN in research contexts should define low weight as BMI <18.5 kg/m2 and require measurable rather than inferred weight phobia. © 2013 Wiley Periodicals, Inc. (Int J Eat Disord 2014; 47:76–84)
An evaluation of approaches for modelling hydrological processes in high‐elevation, glacierized Andean watersheds
Authors: Ragettli S. , Cortés G. , McPhee J. , Pellicciotti F. 
Published: September 2013

AbstractWe use two hydrological models of varying complexity to study the Juncal River Basin in the Central Andes of Chile with the aim to understand the degree of conceptualization and the spatial structure that are needed to model present and future streamflows. We use a conceptual semi‐distributed model based on elevation bands [Water Evaluation and Planning (WEAP)], frequently used for water management, and a physically oriented, fully distributed model [Topographic Kinematic Wave Approximation and Integration ETH Zurich (TOPKAPI‐ETH)] developed for research purposes mainly. We evaluate the ability of the two models to reproduce the key hydrological processes in the basin with emphasis on snow accumulation and melt, streamflow and the relationships between internal processes. Both models are capable of reproducing observed runoff and the evolution of Moderate‐resolution Imaging Spectroradiometer snow cover adequately. In spite of WEAP's simple and conceptual approach for modelling snowmelt and its lack of glacier representation and snow gravitational redistribution as well as a proper routing algorithm, this model can reproduce historical data with a similar goodness of fit as the more complex TOPKAPI‐ETH. We show that the performance of both models can be improved by using measured precipitation gradients of higher temporal resolution. In contrast to the good performance of the conceptual model for the present climate, however, we demonstrate that the simplifications in WEAP lead to error compensation, which results in different predictions in simulated melt and runoff for a potentially warmer future climate. TOPKAPI‐ETH, using a more physical representation of processes, depends less on calibration and thus is less subject to a compensation of errors through different model components. Our results show that data obtained locally in ad hoc short‐term field campaigns are needed to complement data extrapolated from long‐term records for simulating changes in the water cycle of high‐elevation catchments but that these data can only be efficiently used by a model applying a spatially distributed physical representation of hydrological processes. Copyright © 2013 John Wiley & Sons, Ltd.
Air and water flows induced by pumping tests in unconfined aquifers with low‐permeability zones
Authors: Kuang Xingxing , Jiao Jiu Jimmy , Zhang Keni , Mao Deqiang 
Published: September 2013

AbstractAir flows from the atmosphere into an unconfined aquifer when the water table falls during pumping tests. Pumping test results in unconfined aquifers may be significantly affected by low‐permeability zones (LPZs) near the initial water table position, because they restrict the downward movement of air. A transient, three‐dimensional air–water two‐phase flow model is employed to investigate numerically the effects of local heterogeneity on pumping test results in unconfined aquifers. Two cases of local heterogeneities are considered herein: a LPZ around the pumping well and on one side of the pumping well. Results show that the drawdown with the LPZ is significantly greater than that of the homogeneous aquifer. The differences in drawdown are the most significant at intermediate times and gradually diminish at later times. The LPZ significantly reduces air flow from the atmosphere to the aquifer. The pore air velocity in the LPZ is very low. The air pressure at the observation point under the LPZ when air begins to enter is significantly lower than the air pressure of the homogeneous aquifer at the same point. After that, the air pressure increases quickly and then increases slowly. The time for the air pressure to reach the atmospheric pressure is significantly longer. Copyright © 2013 John Wiley & Sons, Ltd.
Solar cycle effects on parallel electric field acceleration of auroral electron beams
Authors: Cattell C. , Dombeck J. , Hanson L. 
Published: September 2013

AbstractWe present the occurrence frequency of downgoing auroral electron beams in magnetic local time and invariant latitude, and the dependence on solar cycle, as indicated by F10.7, on whether the ionospheric foot point of the satellite is illuminated or dark, and on the energy flux carried by the electrons. As previously reported, we find that the occurrence of electron beams peaks in the premidnight local time sector and that solar illumination at the foot point (solar zenith angle) reduces both the occurrence and energy of the electron beams. The effect of solar maximum conditions (indicated by F10.7) is almost as large as the effect of the solar zenith angle. The characteristic energy of the electron beams is dependent on the energy flux carried, in addition to both solar zenith angle and F10.7. The beam energy (and therefore the parallel potential drop) is ~1.6 times higher for during solar minimum than during solar maximum for both dark and illuminated foot points. The beam energy during dark solar minimum conditions is a factor of ~3 more than during sunlit minimum conditions. The “area” covered by intense aurora is also reduced during solar maximum, for both sunlit and dark conditions. There is no evidence that the statistical results are due to the fact that acceleration via parallel electric fields moves to lower latitudes during solar maximum.