bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microwave‐Assisted Hydrothermal Green Synthesis of Analcime Icositetrahedra: Insight into Intermediates Formed in the Reversed Crystal Growth Process
Authors: Samadi‐Maybodi Abdolraouf , Pourali S. Masoomeh 
Published: January 2014

AbstractThis contribution reports new details that we have observed in the early stages of the reversed crystal growth of zeolite analcime icositetrahedra synthesized by a facile microwave‐assisted hydrothermal method in the presence of sodium carboxymethyl cellulose (CMC) as a green template. The detailed time‐dependent evolution of the crystallization and the morphology of the crystals were elucidated by X‐ray diffraction (XRD) and field emission scanning electron microscopy (FE‐SEM) analysis. Under microwave irradiation and in the viscous environment provided by CMC, some kinetically controlled stages provided new information about the early stages of analcime crystal growth; hollow microsphere thin‐shell nanoplatelets and nanorods orderly fill the core, and this creates a thick core. The influence of parameters such as CMC concentration, microwave irradiation time, and hydrothermal reaction time on the crystallinity, size, and morphology of the analcime crystals was thoroughly investigated. Perfect large analcime icositetrahedra were obtained only at CMC concentrations and long microwave irradiation times. Moreover, the employment of acid‐treated seeds led to the formation of analcime nanocrystals of 60 ± 20 nm accompanied by the retained ANA parent. Our results suggest that these newly revealed orientations of the precursors could shed light on the early stages of reversed crystal growth of other zeolites and microstructured materials in the field of materials science and crystal engineering.
Benzotriazole Phenoxide Hafnium Complexes as Efficient Catalysts for the Ring‐Opening Polymerization of Lactide: Synthesis, Characterization, and Kinetics of Polymerization Catalysis
Authors: Chuang Hui‐Ju , Wu Ban‐Hsin , Li Chen‐Yu , Ko Bao‐Tsan 
Published: January 2014

AbstractHafnium complexes bearing bis‐ or tetra‐BTP ligands (BTP = N,O‐bidentate benzotriazole phenoxide) have been synthesized and structurally characterized. The reactions of [Hf(OiPr)4(iPrOH)] with 2‐(2H‐benzotriazol‐2‐yl)‐4,6‐bis(1‐methyl‐1‐phenylethyl)phenol (CMe2PhBTP‐H), 2‐(2H‐benzotriazol‐2‐yl)‐4,6‐di‐tert‐butylphenol (tBuBTP‐H), and 2‐tert‐butyl‐6‐(5‐chloro‐2H‐benzotriazol‐2‐yl)‐4‐methylphenol (TMClBTP‐H) (2.0 mol‐equiv.) in hexane at 30 °C afforded the monomeric hafnium complexes [(CMe2PhBTP)2Hf(OiPr)2] (1), [(tBuBTP)2Hf(OiPr)2] (2), and [(TMClBTP)2Hf(OiPr)2] (3). The bis‐adduct hafnium analogue [(C8BTP)2Hf(OiPr)2] (4) was obtained by similar treatment of the sterically less bulky 2‐(2H‐benzotriazol‐2‐yl)‐4‐(2,4,4‐trimethylpentan‐2‐yl)phenol (C8BTP‐H) as ligand at 0 °C and with a ligand/metal precursor ratio of 2:1, and treatment of [Hf(OiPr)4(iPrOH)] with C8BTP‐H (4.0 mol equiv.) at 30 °C gave the hafnium tetra‐adduct [(C8BTP)4Hf] (5). Single‐site hafnium 4 proved to be an active catalyst in the polymerization of lactide (LA) in solution with “living” and “immortal” characteristics, producing polymers with the expected molecular weights and narrow molecular weight distributions (PDI ≤ 1.30). BTP‐containing Hf complex 5 efficiently catalyzed the polymerization in a controlled fashion even though 160 equiv. of IPA was added to the Hf catalyst present at a low concentration. Kinetic tests for the polymerization of LA were conducted to compare the activities of hafnium alkoxides 1–4; a kinetic study of 4 revealed the polymerizations to be first order in both complex 4 and L‐LA concentrations.
A Robust, Well‐Defined Homogeneous Silver(I) Catalyst for Mild Intramolecular Hydroamination of 2‐Ethynylanilines Leading to Indoles
Authors: McNulty James , Keskar Kunal 
Published: January 2014

AbstractA highly efficient, chemically stable and well‐defined homogeneous silver(I) catalyst is reported for the room temperature, intramolecular hydroamination of 2‐alkynylanilines leading to indole derivatives.
Diels–Alder Reaction of Ethyl 3‐Benzamido‐2‐oxo‐6‐(trifluoromethyl)‐2H‐pyran‐5‐carboxylate with Alkoxyalkenes as an Effective Approach to Trifluoromethyl‐Containing 3‐Aminobenzoic Acid Derivatives
Authors: Kondratov Ivan S. , Tolmachova Nataliya A. , Dolovanyuk Violetta G. , Gerus Igor I. , Bergander Klaus , Daniliuc Constantin‐Gabriel , Haufe Günter 
Published: January 2014

AbstractThe Diels–Alder reactions of ethyl 3‐benzamido‐2‐oxo‐6‐(trifluoromethyl)‐2H‐pyran‐5‐carboxylate with ethyl vinyl ether, 2‐methoxypropene, and 1‐ethoxypropene were investigated. Under different reaction conditions, intermediate oxabicyclo[2.2.2]octenones, alkoxycyclohexadienes, or aromatic products [5‐benzamido‐2‐(trifluoromethyl)benzoates] were formed. The reaction is useful for the preparation of some hitherto unknown trifluoromethyl‐containing derivatives of 3‐aminobenzoic acid.
Cyclocondensation of Hydroxylamine with 1,3‐Bis(het)arylmonothio 1,3‐Diketones and 1,3‐Bis(het)aryl‐3‐(methylthio)‐2‐prop­enones: Synthesis of 3,5‐Bis(het)arylisoxazoles with Complementary Regioselectivity
Authors: Raghava Byregowda , Parameshwarappa Gangajji , Acharya Anand , Swaroop Toreshettahally R. , Rangappa Kanchugarakoppal S. , Ila Hiriyakkanavar 
Published: January 2014

AbstractEfficient routes for the regioselective synthesis of 3,5‐bis(het)arylisoxazoles with complementary regioselectivity have been developed. The methods involve the cyclocondensation of hydroxylamine hydrochloride with either 1,3‐bis(het)aryl‐monothio‐substituted 1,3‐diketones 1 or with 3‐methylthio‐1,3‐bis(het)aryl‐2‐propenones 2 under various reaction conditions. In the first protocol, diketones 1 were treated with hydroxylamine hydrochloride in the presence of sodium acetate/acetic acid (pH 2.2) in refluxing ethanol/benzene to give 3,5‐bis(het)arylisoxazoles 5, in which the het(aryl) moiety attached to thiocarbonyl group of the monothio‐substituted 1,3‐diketones is installed at the 3‐position. On the other hand, the reaction of hydroxylamine hydrochloride with 3‐(methylthio)‐1,3‐bis(het)aryl‐2‐propenones 2 in the presence of barium hydroxide in refluxing ethanol gave 3,5‐bis(het)arylisoxazoles 6 with complementary regioselectivity in high yields. A probable mechanism for the formation of regioisomeric isoxazoles 5 and 6 from precursors 1 and 2 has been suggested.
Synthesis and Reactions of Triptycene‐Derived Bromocalix[5]arenes: Conformational Transformation from Cone to 1,2‐Alternate
Authors: Xia Yu‐Xiang , Han Ying , Chen Chuan‐Feng 
Published: January 2014

AbstractTriptycene‐derived p‐dibromocalix[5]arene was synthesized by a fragment‐coupling approach, whereas treatment of the triptycene‐derived calix[5]arene containing three p‐tert‐butyl phenol groups and a 1,8‐dimethoxytriptycene moiety with excess bromine in dichloromethane at room temperature produced triptycene‐derived p‐pentabromocalix[5]arene directly. Methyl etherification and Suzuki coupling reactions were then carried out. As a result, a series of triptycene‐derived calix[5]arene derivatives in fixed cone and 1,2‐alternate conformations were obtained. Moreover, conformation transformations of triptycene‐derived calix[5]arenes from cone to 1,2‐alternate forms could also be achieved.
Highly Regioselective Cascade Formal Nucleophilic Substitution and Aldol Condensation of 2‐Aroyl‐1‐chlorocyclopropanecarboxylic Esters
Authors: Zhang Min , Guo Junkai , Gong Yuefa 
Published: January 2014

AbstractA highly regioselective cascade formal nucleophilic substitution and aldol reaction of 2‐aroyl‐1‐chlorocyclopropanecarboxylic esters with salicylic aldehydes is described. Under basic conditions, 2‐aroyl‐1‐chlorocyclopropanecarboxylic esters are easily converted into cyclopropene intermediates by simple 1,2‐elimination of hydrogen chloride. This highly reactive cyclopropene quickly combines with salicylic aldehyde through a regioselective oxa‐addition to the strained C=C bond and a subsequent intramolecular aldol reaction to construct C–O and C–C bonds concomitantly and afford tetrahydrocyclopropa[b]chromene derivatives.
Sequential Catalyst Phosphine/Secondary Amine Promoted [1+4]/Rearrangement Domino Reaction for the Construction of (2H)‐Pyrans and 2‐Oxabicyclo[2.2.2]oct‐5‐ene Skeletons
Authors: Xie Peizhong , Yang Jie , Zheng Jie , Huang You 
Published: January 2014

AbstractSequential catalysis of a [2+4] reaction between a Baylis–Hillman carbonate and a β,γ‐unsaturated α‐oxo ester for the synthesis of 2‐methyl‐2H‐pyran was developed. The use of a Morita–Baylis–Hillman carbonate as a C2 synthon is first disclosed in this reaction. This method offers a new approach to the construction of 2‐methyl‐2H‐pyrans and 2‐oxabicyclo[2.2.2]oct‐5‐ene skeletons.
Chemical Modification of Polymer Ion‐Selective Membrane Electrode Surfaces
Authors: Pawlak Marcin , Bakker Eric 
Published: January 2014

AbstractMembrane/sample interactions play a crucial role in the biomedical application of ion selective electrodes (ISEs). Modulation of membrane surface properties can be used as a way to enhance biocompatibility and in fabrication of biosensors through biomolecules immobilization. This review discusses advances in methods and materials used for the surface modifications of polymeric ion‐selective membranes in view of their applications in clinical diagnostics.
Effects of the commercial antiandrogen flutamide on the biomarkers of reproduction in male Murray rainbowfish (Melanotaenia fluviatilis)
Authors: Bhatia Harpreet , Kumar Anupama , Ogino Yukiko , Du Jun , Gregg Adrienne , Chapman John , McLaughlin Mike J. , Iguchi Taisen 
Published: January 2014

Abstract

The endocrine responses in male Murray rainbowfish (Melanotaenia fluviatilis) were evaluated after exposures to biologically active concentrations of the nonsteroidal pharmaceutical, flutamide. Fish were exposed to nominal concentrations of 125 µg/L, 250 µg/L, 500 µg/L, and 1000 µg/L of flutamide for 7 d, after which plasma vitellogenin concentration; brain aromatase activity; and hepatic expression of the genes for vitellogenin, choriogenin, and androgen and estrogen receptors were assessed. Qualitative assessment of the testes of the fish exposed to flutamide exhibited hindrance in the transformation of spermatogonia to spermatozoa and increased testicular anomalies, such as multinucleated and pyknotic cells and interstitial fibrosis. An increase in the hepatosomatic index with respect to the controls was noted after treating the fish with flutamide at all concentrations. Vitellogenin was induced in plasma in the 1000 µg/L flutamide group. The activity of aromatase in the brain declined significantly after exposures to flutamide at all concentrations. Males exposed to 1000 µg/L of flutamide showed a downregulation in the genes encoding androgen receptors α and β. The expression of the gene for the estrogen receptor α was induced and of vitellogenin was downregulated after treatment with 250 µg/L to 1000 µg/L of flutamide. The results suggest that 7-d exposures to 125 µg/L to 1000 µg/L flutamide can impair the reproductive endocrine system in male Murray rainbowfish at multiple levels by an antiandrogenic mode of action. Environ Toxicol Chem 2014;33:1098–1107. © 2014 SETAC
A survey of cognitive radio and TV white spaces in Malaysia
Authors: Elshafie H. , Fisal N. , Abbas M. , Hassan W.A. , Mohamad H. , Ramli N. , Jayavalan S. , Zubair S. 
Published: January 2014

AbstractCognitive radio (CR) enables spectrum sharing by allowing new unlicensed services from secondary users to operate in pre‐allocated bands in an opportunistic manner. TV white space (TVWS) is a portion of the spectrum in ultra‐high frequency (UHF) and very‐high frequency bands, which is not utilised by primary users in specific time and location. It is envisaged that more spectrum will be available after digital switchover (DSO) TV transmission replaces the current analogue system. Recently, the regulators in the USA and in the UK have given approval for companies to operate new communication systems with the capability of utilising TVWS spectrum. This paper provides a comprehensive overview of the CR technology and quantifies the TVWS status in Malaysia to expose the spectrum reuse opportunities for future secondary user deployment. Taking the 18 major cities in Malaysia into consideration, we find that all seven TV stations utilise from two to seven of the UHF channels. In our analysis, three usage scenarios were considered, where the utilisation of the 40 UHF channels is full, half and a third. For each case, it was discovered that TVWS was 82.5%, 65% and 46.1%, which can be opportunistically utilised by CR users. Copyright © 2014 John Wiley & Sons, Ltd.
Characteristics and developmental mechanisms of mud volcanoes on the southern margin of the Junggar Basin, NW China
Authors: Wan Zhifeng , Shi Qiuhua , Zhang Qian , Cai Song , Xia Bin 
Published: January 2014

AbstractMud volcanoes have provided much meaningful information about the deep Earth and the recent crustal and neotectonic movements in an area for over 200 years. However, the triggering mechanisms have puzzled geologists for a long time. This study investigated the factors controlling mud volcano activity and the triggering mechanisms of mud volcano eruptions on the southern margin of the Junggar Basin, NW China. The Baiyanggou, Aiqigou and Dushanzi mud volcanoes are all located along the Dushanzi Anticline, which belongs to the third anticline belt on the southern margin of the basin. The extensive, thick mudstone at depth provides a wealth of material for the formation of mud volcanoes. Simultaneously, the overpressure serves as the driving force for the eruption of the mud volcanoes. The torsional–compressional stress field created by the collision between the Indian and Eurasian plates not only enhanced the abnormal formational pressure in the region but also lead to the development of extensional faults in the core of the Dushanzi Anticline, which served as the conduits for the mud volcanoes. The continuous collision between the Indian and Eurasian plates and the regional torsional–compressional stress field may largely control the cyclical activity of the mud volcanoes and serve as their primary trigger mechanism. Copyright © 2014 John Wiley & Sons, Ltd.
Mesenchymal stem cell and gelatin microparticle encapsulation in thermally and chemically gelling injectable hydrogels for tissue engineering
Authors: Tzouanas Stephanie N. , Ekenseair Adam K. , Kasper F. Kurtis , Mikos Antonios G. 
Published: January 2014

AbstractIn this work, we investigated the viability and osteogenic differentiation of mesenchymal stem cells encapsulated with gelatin microparticles (GMPs) in an injectable, chemically and thermally gelling hydrogel system combining poly(N‐isopropylacrylamide)‐based thermogelling macromers containing pendant epoxy rings with polyamidoamine‐based hydrophilic and degradable diamine crosslinking macromers. Specifically, we studied how the parameters of GMP size and loading ratio affected the viability and differentiation of cells encapsulated within the hydrogel. We also examined the effects of cell and GMP co‐encapsulation on hydrogel mineralization. Cells demonstrated long‐term viability within the hydrogels, which was shown to depend on GMP size and loading ratio. In particular, increased interaction of cells and GMPs through greater available GMP surface area, use of an epoxy‐based chemical gelation mechanism, and the tunable high water content of the thermogelled hydrogels led to favorable long‐term cell viability. Compared with cellular hydrogels without GMPs, hydrogels co‐encapsulating cells and GMPs demonstrated greater production of alkaline phosphatase by cells at all time‐points and a transient early enhancement of hydrogel mineralization for larger GMPs at higher loading ratios. Such injectable, in situ forming hydrogels capable of delivering and maintaining populations of encapsulated mesenchymal stem cells and promoting mineralization in vitro offer promise as novel therapies for applications in tissue engineering and regenerative medicine. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1222–1230, 2014.
Ultrabroadband Er:fiber lasers
Authors: Brida Daniele , Krauss Günther , Sell Alexander , Leitenstorfer Alfred 
Published: January 2014

AbstractThe state of the art of ultrafast Er:fiber technology is reviewed. Such lasers are increasingly used for generation of ultrabroadband and widely tunable pulse trains. Er:fiber sources prove to be flexible, compact and robust with important applications in fundamental and interdisciplinary sciences. After a short overview of different oscillator and amplifier designs the discussion focuses on coherent and tailored supercontinuum generation in highly nonlinear germanosilicate fibers. This approach enables a tuning range spanning from the visible to the mid infrared, synthesis of single‐cycle light pulses and passive locking of the carrier‐envelope phase.
Understanding the Compensation of Nonprofit Executive Directors: Examining the Influence of Performance and Organizational Characteristics
Authors: Grasse Nathan , Davis Trenton , Ihrke Douglas 
Published: January 2014

AbstractIn this study we aimed to provide a better understanding of executive compensation in nonprofit organizations. We examined factors including organizational size, market, subsector, organizational type, staffing level, and organizational performance as potential influences driving variation across the nonprofit sector. The models utilize data on the population of nonprofit organizations required to file Form 990 returns with the Internal Revenue Service in order to broadly examine compensation. The results indicate associations between various measures of performance and compensation in nonprofit orga‐nizations and also suggest that different types of nonprofits may be sensitive to different measures of performance.
Modifications in parent feeding practices and child diet during family‐based behavioral treatment improve child zBMI
Authors: Holland Jodi Cahill , Kolko Rachel P. , Stein Richard I. , Welch R. Robinson , Perri Michael G. , Schechtman Kenneth B. , Saelens Brian E. , Epstein Leonard H. , Wilfley Denise E. 
Published: January 2014

ObjectiveTo examine associations between modifications in parent feeding practices, child diet, and child weight status after treatment and to evaluate dietary mediators.MethodsChildren classified as overweight or obese and 7‐11 years old (N = 170) completed a 16‐session family‐based behavioral weight loss treatment (FBT) program. Anthropometrics (standardized body mass index (zBMI)), Child Feeding Questionnaire, and 24‐hr dietary recalls were collected at baseline and post‐FBT. Linear regression predicted child zBMI change. Single and multiple mediation tested child dietary modifications as mediators between change in parent feeding practices and child zBMI.ResultsRestrictive parent feeding practices significantly decreased during FBT. Reductions in parent restriction, child weight concern, child's total energy intake, and percent energy from fat, and increases in parent perceived responsibility, and child percent energy from protein, predicted reductions in child zBMI. Change in child total energy intake mediated the relation between parent restriction and child zBMI change after accounting for covariates and additional dietary mediators.ConclusionsFBT is associated with a decrease in parental restriction, which is associated with reductions in child relative weight, which was mediated by a decrease in child energy intake. Teaching parents to reduce children's energy intake without being overly restrictive may improve child weight.
One‐Pot Synthesis and Applications of N‐Heteroaryl Iodonium Salts
Authors: Bielawski Marcin , Malmgren Joel , Pardo Leticia M. , Wikmark Ylva , Olofsson Berit 
Published: January 2014

AbstractAn efficient one‐pot synthesis of N‐heteroaryl iodonium triflates from the corresponding N‐heteroaryl iodide and arene has been developed. The reaction conditions resemble our previous one‐pot syntheses, with suitable modifications to allow N‐heteroaryl groups. The reaction time is only 30 min, and no anion exchange is required. The obtained iodonium salts were isolated in a protonated form, these salts can either be employed directly in applications or be deprotonated prior to use. The aryl groups were chosen to induce chemoselective transfer of the heteroaryl moiety to various nucleophiles. The reactivity and chemoselectivity of these iodonium salts were demonstrated by selectively introducing a pyridyl moiety onto both oxygen and carbon nucleophiles in good yields.
Parametric Influences on the Sensitivity of Exploding Foil Initiators
Authors: Chen Qing‐Chou , Fu Qiu‐Bo , Chen Lang , Han Zhong‐Fei 
Published: January 2014

AbstractAnalyses of firings by the up‐and‐down method were employed to gain a better understanding of the influences of foil bridge width, foil thickness, flyer thickness, and barrel length on the sensitivity of exploding foil initiators. Characterization was performed via the mean threshold voltage. The results showed that the mean threshold voltage of exploding foil initiators was reduced by 16 % when the foil bridge width was reduced from 0.4 mm to 0.3 mm, which means that a reduced foil bridge width could decrease the mean threshold voltage of exploding foil initiators as suggested by theoretical analysis. The mean threshold voltage of exploding foil initiators was reduced by 20 % as the flyer thickness was decreased from 50 μm to 25 μm, which could be an efficient way to improve the sensitivity of exploding foil initiators. The flyer accelerated to over 90 % maximum velocity after flying 0.15 mm in a fine barrel, which revealed that exceeding a barrel length of 0.15 mm has little effect on the performance of exploding foil initiators.
Indigenous American species of the Bemisia tabaci complex are still widespread in the Americas
Authors: Barbosa Leonardo da F , Marubayashi Julio M , De Marchi Bruno R , Yuki Valdir A , Pavan Marcelo A , Moriones Enrique , Navas‐Castillo Jesús , Krause‐Sakate Renate 
Published: January 2014

AbstractBemisia tabaci is a complex of at least 36 putative cryptic species. Since the late 1980s, the Middle East–Asia Minor 1 species (MEAM1, formerly known as the B biotype), has emerged in many tropical and subtropical regions of the world and in some areas has displaced the indigenous populations of B. tabaci. Based on analysis of the mtCOI gene, two indigenous species native to America have been reported: New World (NW, formerly the A biotype) and New World 2 (NW2). NW is present at least in Argentina, Brazil, Martinique, Mexico, Texas and Venezuela, and NW2 in Argentina, Bolivia and Brazil. Wild plants (Euphorbia sp. and Ipomoea sp.), as well as important crops such as tomato, bean and cotton, are still hosts for native B. tabaci populations in the Americas. MEAM1 has not completely displaced the native B. tabaci from the Americas. © 2014 Society of Chemical Industry