bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel features of boundary cap cells revealed by the analysis of newly identified molecular markers
Authors: Coulpier Fanny , Le Crom Stéphane , Maro Géraldine S. , Manent Jan , Giovannini Marco , Maciorowski Zofia , Fischer Andreas , Gessler Manfred , Charnay Patrick , Topilko Piotr 
Published: February 2009

AbstractNeural crest (NC) cells are a multipotent, highly migratory cell population that generates most of the components of the peripheral nervous system (PNS), including the glial Schwann cells (SC) and boundary cap (BC) cells. These latter cells are located at the interface between the central nervous system and PNS, at the exit/entry points of ventral motor/dorsal sensory axons and give rise to all SC in the nerve roots and to a subset of nociceptive neurons and satellite cells in the dorsal root ganglia. In the present study we have compared BC cells with two closely related cell types, NC and Schwann cell precursors (SCpr), by RNA profiling. This led to the definition of a set of 10 genes that show specific expression in BC cells and/or in their derivatives along the nerve roots. Analysis of the expression of these genes during mouse development revealed novel features, of those most important are: (i) dorsal and ventral nerve root BC cell derivatives express different sets of genes, suggesting that they have distinct properties; (ii) these cells undergo major modifications in their gene expression pattern between embryonic days 14.5 and 17.5, possibly linked to the SCpr‐immature Schwann cell transition; (iii) nerve roots SC differ from more distal SC not only in their origins and locations, but also in their gene expression patterns. In conclusion, the identification of these novel makers opens the way for a detailed characterization of BC cells in both mouse and man. © 2009 Wiley‐Liss, Inc.
Na+ transport in cardiac myocytes; Implications for excitation‐contraction coupling
Authors: Bers Donald M. , Despa Sanda 
Published: February 2009

AbstractIntracellular Na+ concentration ([Na+]i) is very important in modulating the contractile and electrical activity of the heart. Upon electrical excitation of the myocardium, voltage‐dependent Na+ channels open, triggering the upstroke of the action potential (AP). During the AP, Ca2+ enters the myocytes via L‐type Ca2+ channels. This triggers Ca2+ release from the sarcoplasmic reticulum (SR) and thus activates contraction. Relaxation occurs when cytosolic Ca2+ declines, mainly due to re‐uptake into the SR via SR Ca2+‐ATPase and extrusion from the cell via the Na+/Ca2+ exchanger (NCX). NCX extrudes one Ca2+ ion in exchange for three Na+ ions and its activity is critically regulated by [Na+]i. Thus, via NCX, [Na+]i is centrally involved in the regulation of intracellular [Ca2+] and contractility. Na+ brought in by Na+ channels, NCX and other Na+ entry pathways is extruded by the Na+/K+ pump (NKA) to keep [Na+]i low. NKA is regulated by phospholemman, a small sarcolemmal protein that associates with NKA. Unphosphorylated phospholemman inhibits NKA by decreasing the pump affinity for internal Na+ and this inhibition is relieved upon phosphorylation. Here we discuss the main characteristics of the Na+ transport pathways in cardiac myocytes and their physiological and pathophysiological relevance. © 2009 IUBMB IUBMB Life, 61(3): 215–221, 2009
Extensive conformational searches of 13 representative dipeptides and an efficient method for dipeptide structure determinations based on amino acid conformers
Authors: Yu Wenbo , Xu Xuee , Li Hongbao , Pang Rui , Fang Kun , Lin Zijing 
Published: February 2009

AbstractConformations of peptides are the basis for their property studies and the predictions of peptide structures are highly important in life science but very complex in practice. Here, thorough searches on the potential energy surfaces of 13 representative dipeptides by considering all possible combinations of the bond rotational degrees of freedom are performed using the density functional theory based methods. Careful analyses of the conformers of the 13 dipeptides and the corresponding amino acids reveal the connections between the structures of dipeptide and amino acids. A method for finding all important dipeptide conformers by optimizing a small number of trial structures generated by suitable superposition of the parent amino acid conformations is thus proposed. Applying the method to another eight dipeptides carefully examined by others shows that the new approach is both highly efficient and reliable by providing the most complete ensembles of dipeptide conformers and much improved agreements between the theoretical and experimental IR spectra. The method opens the door for the determination of the stable structures of all dipeptides with a manageable amount of effort. Preliminary result on the applicability of the method to the tripeptide structure determination is also presented. The results are the first step towards proving Anfinsen's hypothesis by revealing the relationships between the structures of the simplest peptide and its constituting amino acids. It implies that the structures of peptides are not only determined by their amino acid sequences, but also closely linked with the amino acid conformations. © 2009 Wiley Periodicals, Inc. J Comput Chem 2009
On triazoles. XL [1]. Non catalytic dehalogenation of some 5‐chloro‐1,2,4‐triazolo[1,5‐a]pyrimidine derivatives
Authors: Berecz Gábor , Reiter József , Császár János 
Published: February 2009

AbstractA non catalytic dehalogenation method of type 4 5‐chloro‐1,2,4‐triazolo[1,5‐a]pyrimidine derivatives based on the hydrolysis of the corresponding type 5 p‐toluenesulphonyl hydrazones with diluted aqueous sodium carbonate solution was elaborated. The method provides the required 5‐unsubstituted derivatives 6 also in those cases when the simple hydrogenation is not possible. Using deuterium oxide as the solvent of the hydrolysis, deuterium atoms also could be inserted into position 5 of derivatives 6. Different by‐products of the reactions were also isolated, and a possible explanation was given for their formation.
Synthesis of spiro‐1‐pyrazolines by the 1,3‐dipolar cycloaddition of exocyclic α,β‐unsaturated ketones with diazomethane
Authors: Silva Artur M. S. , Cavaleiro José A. S. , Lévai Albert , Patonay Tamás 
Published: February 2009

Abstract1,3‐Dipolar cycloadditions of exocyclic α,β‐unsaturated ketones 1‐22 with diazomethane afforded spiro‐1‐pyrazolines 23‐44 in a diastereospecific reaction. The structure and stereochemistry of each compound synthesised has been elucidated by nmr spectroscopic measurements and other analytical techniques. It has been proven that the stereochemistry of the starting α,β‐enones was retained in the course of these cycloadditions.
The preparation of 4,5‐dihydro‐2H‐benz[e]indazoles from dilithiated 2‐tetralone phenylhydrazone and aromatic esters
Authors: Angel April J. , Finefrock Anne E. , Williams Angela R. , Townsend Jessica D. , Nguyen Thuy‐Ha V. , Hurst Douglas R. , Heldrich Frederick J. , Beam Charles F. , Badejo Ibraheem T. 
Published: February 2009

AbstractThe phenylhydrazone of 2‐tetralone was dilithiated with excess lithium diisopropylamide followed by condensation with several aromatic esters, and the resulting intermediates were acid cyclized to 4,5‐dihydro‐2H‐benz[e]indazoles.
Heterocyclization reactions of azinoisocyanates. Synthesis of 2H‐1,2,4‐triazol‐3(4H)‐one derivatives
Authors: Lee Kee‐Jung , Kim Jin Lyang , Hong Mun Ki , Lee Jung Yong 
Published: February 2009

AbstractThe reaction of 1‐aminoethylidenehydrazones 9 with di‐tert‐butyl dicarbonate and 4‐dimethylaminopyridine led to the corresponding azinoisocyanates 10, which underwent thermal rearrangement under the reaction conditions to give 4‐(tert‐butoxycarbonyl)‐5‐methyl‐2H‐1,2,4‐triazol‐3(4H)‐ones 14. However, amidrazone 17 gave 2‐(2‐tert‐butoxycarbonyloxy‐2‐phenyl)ethyl‐4‐(tert‐butoxycarbonyl)‐5‐methyl‐2H‐1,2,4‐triazol‐3(4H)‐one 22 and N‐aziridinyliminocarbamate 18 under the similar conditions.
Synthesis of 2(3H)‐benzoxazolinone derivatives as potential beta‐3‐adrenergic receptor ligands
Authors: Delhomel J. F. , Yous S. , Depreux P. , Lesieur D. 
Published: February 2009

AbstractBeta‐3‐subtype‐adrenoceptors mediate lipolysis and in the search for potential beta‐3‐adrenergic receptor agonists for the treatment of obesity, we designed new arylethanolamines, structures B1 and B2, derived from 2(3H)‐benzoxazolinone. To obtain these target compounds as starting materials, various N‐benzyl‐[2(3H)‐benzoxazolinon‐6‐yl]ethylamines were used.
Studies on pyrrolidinone. Synthesis of aza analogs of podophyllotoxin and related compounds
Authors: Legrand Anne , Rigo Benoît , Gautret Philippe , Henichart Jean‐Pierre , Couturier Daniel 
Published: February 2009

AbstractThe Friedel‐Crafts cyclisation ofN‐benzhydrylpyroglutamic acids whose aromatic rings are substituted by methoxy or methylenedioxy groups gives podophyllotoxin analogs whose lactone ring was changed to a lactam.
Credit demand in Mozambican manufacturing
Authors: Byiers Bruce , Rand John , Tarp Finn , Bentzen Jeanet 
Published: February 2009

AbstractThis paper uses two industrial firm surveys to identify the key determinants of credit demand in Mozambican manufacturing. We construct five different measures of being credit constrained and estimate desired debt demand. Besides firm size and ownership structure, we find evidence that general manager education and business association membership are associated with whether a firm is credit constrained or not. Using our preferred measure of credit constraint suggests that around 43 per cent of the firms surveyed are constrained, and these enterprises would almost triple their debt burden if borrowing constraints were relaxed. © 2016 The Authors. Journal of International Development published by John Wiley & Sons, Ltd.
A hydroclimatic index for examining patterns of drought in the Colorado River Basin
Authors: Ellis Andrew W. , Goodrich Gregory B. , Garfin Gregg M. 
Published: February 2009

AbstractTo better understand drought occurrence in the Colorado River Basin (CRB) of the southwestern United States we used a hydroclimatic index to create a historical record of drought coverage and analysed the linear trend and relationships with key climate teleconnections. The past century was characterized by an increase in drought coverage during the warm portion of the year almost exclusively as a result of climatic warming. In recent decades, a significant increase in the drought coverage occurred earlier in the year, during the spring season, primarily as a function of warming, but in combination with a decline in precipitation for a significant portion of the basin. The El Niño (La Niña) phase of the El Niño‐Southern Oscillation (ENSO) phenomenon is associated with a smaller (larger) area of drought during fall and winter, and the ENSO phase during the preceding six months is a significant predictor. The area of drought within the CRB is larger (smaller) during the warm (cold) phases of the Atlantic Multi‐decadal Oscillation (AMO) and the Pacific Decadal Oscillation (PDO), although the relationship with the PDO is weak. Monthly AMO values for the two years preceding drought provide minor predictability. Decadal averages of drought coverage closely follow those of both the AMO and PDO index. However, the nature of the PDO‐drought relationship is reversed over the two halves of the historical record, possibly indicating a dominance of the AMO over the PDO in influencing drought in the region. Teleconnection‐drought relationships are stronger for the southern portion of the basin. Trends in drought coverage, the current phases of the AMO and PDO, climate change projections of regional warming, and the likelihood of continued rapid population growth could result in significant water resource problems within the CRB. Copyright © 2009 Royal Meteorological Society
Systematic Comparison of HEA and HEMA as Initiators in Enzymatic Ring‐Opening Polymerizations
Authors: Xiao Yan , Takwa Mohamad , Hult Karl , Koning Cor E. , Heise Andreas , Martinelle Mats 
Published: February 2009

AbstractTwo initiators containing a cleavable ester bond were compared in the lipase‐catalyzed ROP of CL and PDL. The results show that transesterification reactions are present at high rates throughout the enzymatic ROP and start at low conversion. HEA and HEMA displayed similar reaction efficiencies as initiators (acyl acceptors) in the enzymatic ROP. However, transacylation reactions on the HEA‐initiated polyesters were found to be 15 times faster. While in both cases the amount of HEA‐ and HEMA‐initiated polymers could be maximized by short reaction times, a well‐defined (meth)acrylation by this approach was not possible. Our results show that transesterification reactions have to be considered when performing an enzyme‐catalyzed ROP.magnified image
Synthesis of Oligosaccharide‐Branched Ribofuranan by Ring‐Opening Polymerization of a New Anhydroribo Trisaccharide Monomer
Authors: Yoshida Dai , Han Shuqin , Narita Kei‐Ichi , Hattori Kazuyuki , Yoshida Takashi 
Published: February 2009

AbstractA new anhydroribotrisaccharide monomer, A2B3LR (1), was synthesized and ROP was carried out to elucidate the polymerizability and to obtain oligosaccharide‐branched polysaccharides with defined structures. The new trisaccharide monomer was found to be polymerized readily with BF3 · OEt2 as a catalyst at −40 °C to give a lactose‐branched polymer. Copolymerization with ADBR gave the corresponding copolymers in good yields. After removal of protective benzyl groups, D‐lactose‐branched ribofuranans with free hydroxyl groups were obtained in good yields. The structure of polymers was analyzed by 1H, 13C, and two‐dimensional NMR measurements, suggesting that D‐lactose‐branched ribofuranans had (1 → 5)‐α stereoregularity.magnified image
Ultraviolet photofragmentation of biomolecular ions
Authors: Reilly James P. 
Published: February 2009

AbstractMass spectrometric identification of all types of molecules relies on the observation and interpretation of ion fragmentation patterns. Peptides, proteins, carbohydrates, and nucleic acids that are often found as components of complex biological samples represent particularly important challenges. The most common strategies for fragmenting biomolecular ions include low‐ and high‐energy collisional activation, post‐source decay, and electron capture or transfer dissociation. Each of these methods has its own idiosyncrasies and advantages but encounters problems with some types of samples. Novel fragmentation methods that can offer improvements are always desirable. One approach that has been under study for years but is not yet incorporated into a commercial instrument is ultraviolet photofragmentation. This review discusses experimental results on various biological molecules that have been generated by several research groups using different light wavelengths and mass analyzers. Work involving short‐wavelength vacuum ultraviolet light is particularly emphasized. The characteristics of photofragmentation are examined and its advantages summarized. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 28:425–447, 2009
Motor learning in essential tremor
Authors: Shill Holly A. , De La Vega Frederick J. , Samanta Johan , Stacy Mark 
Published: February 2009

AbstractClassical conditioning is abnormal in patients with cerebellar degeneration. Pathological studies have recently demonstrated the finding of Purkinje cell loss in a subset of essential tremor (ET). We studied 10 subjects with long duration ET using a blink reflex conditioning paradigm and compared them with nine controls. A 55.6% reduction in motor learning was seen in the first block of stimulation and this finding persisted across all subsequent trials. We conclude that motor learning is significantly abnormal in subjects with advanced ET and likely reflects pathological involvement of the cerebellum. © 2009 Movement Disorder Society
Designing and pricing menus of extended warranty contracts
Authors: Hartman Joseph C. , Laksana Kamonkan 
Published: February 2009

AbstractExtended warranties provide “piece of mind” to a consumer in that product failures which occur after the base warranty expires are rectified at little or no cost. They also provide an additional source of revenue for manufacturers or third‐party providers, such as retailers or insurance providers, and help cultivate consumer loyalty. In this article, we analyze a number of extended warranty contracts which differ in design, including restrictions on deferrals and renewals. With the use of dynamic programming, we compute the optimal strategy for a consumer with perfect information and determine the optimal pricing policy for the provider given the consumer's risk characterization. We also provide insight into when different contracts should be issued. Finally, we illustrate how profits can be dramatically increased by offering menus of warranty contracts, as opposed to stand alone contracts, with the use of integer programming. Surprisingly, risk‐taking consumers provide the greatest benefit to offering menus. These insights can help a company develop a comprehensive warranty planning strategy for given products or product lines. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009
Reciprocity Relations in Newtonian and Eshelbian Mechanics
Authors: Kienzler Reinhold 
Published: February 2009

AbstractBy considering a stressed body subjected sequentially to a material displacement of a defect and the application of a physical force, a reciprocity theorem analogous to that of Betti/Maxwell has been established which couples Newtonian and Eshelbian mechanics. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Self‐limited febrile syndromes temporally associated with the use of propofol for sedation in gastrointestinal endoscopic procedures
Authors: Blossom D. B. , Chen T. H. , Li J. , Langer A. J. , Carpenter L. R. , Glenshaw M. T. , Gould C. V. , Weltman A. , Srinivasan A. 
Published: February 2009

AbstractPurposeTo investigate cases of febrile illnesses in patients who received propofol for sedation during gastrointestinal endoscopy.MethodsActive case finding for patients who underwent endoscopy between 1 April and 30 May 2007 and suffered unexplained fever, chills, or myalgia within 48 hour after the procedure. We reviewed medications and clinical practices to find factors associated with the reactions.ResultsSeventy‐four cases at eight facilities in five states were identified yielding a rate of 36 reactions per 1000 procedures, compared with a baseline rate of 0.6 per 1000. The majority of patients experienced self‐limited fever (89.2%), chills (73.0%), or myalgia (63.5%). Blood samples from five patients were collected for culture; no organisms grew. All health care facilities that reported cases and fully participated in the investigation (n = 7) had received a common lot of propofol just before recognition of the first case. Bacterial endotoxin and sterility testing on unopened vials from this lot of propofol showed no abnormalities. Cases terminated after facilities stopped using the associated lot of propofol.ConclusionsWe found a temporal association between a particular lot of propofol and an outbreak of febrile illnesses at several healthcare facilities performing endoscopy. When propofol is used to sedate patients for endoscopy, fever is a rare outcome and healthcare professionals should investigate clusters of these reactions. Post‐procedure surveillance is important to identify possible medication reactions. Copyright © 2009 John Wiley & Sons, Ltd.
Morphology, thermal, and rheological behavior of nylon 11/multi‐walled carbon nanotube nanocomposites prepared by melt compounding
Authors: Huang Shu , Wang Min , Liu Tianxi , Zhang Wei‐De , Tjiu Wuiwui Chauhari , He Chaobin , Lu Xuehong 
Published: February 2009

AbstractNylon 11 (PA11) nanocomposites with different loadings of multi‐walled carbon nanotubes (MWNTs) were prepared by melt compounding. Scanning electron microscopy images on the fracture surfaces of the composites showed a uniform dispersion of MWNTs throughout the matrix. The presence of the MWNTs significantly improved the thermal stability and enhanced the storage modulus (G′) of the polymer matrix. Melt rheology studies showed that, compared with neat PA11, the incorporation of MWNT into the matrix resulted in higher complex viscosities (|η*|), storage modulus (G′), loss modulus (G″), and lower loss factor (tanδ). PA11 and its nanocomposites containing less than 1 wt% MWNTs showed similar frequency dependencies and reached a Newtonian plateau at low frequencies. For the nanocomposite with 2 wt% MWNTs, the regional network was destroyed and the orientation of the MWNTs during shearing exhibited a very strong shear thinning effect. The complex viscosities (|η*|) of the nanocomposites are larger than that of neat PA11 and decreased with increasing the temperature. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Fabrication of barium titanate nanoparticles‐polymethylmethacrylate composite films and their dielectric properties
Authors: Kobayashi Y. , Kurosawa A. , Nagao D. , Konno M. 
Published: February 2009

AbstractA method for incorporating barium titanate (BT) nanoparticles into polymethylmethacrylate (PMMA) is proposed to prepare composite films with a high dielectric constant and high transparency. BT particles with particle sizes of 7.8–24.0 nm and crystal sizes of 8.60–17.7 nm were synthesized with a complex alkoxide method. Surface of the BT particles was modified with 3‐methacryloxypropyltrimethoxysilane to introduce double bonds that was grafted with PMMA. The PMMA‐grafted BT particles were suspended in PMMA/N‐methyl‐2‐pyrrodinone solution and spin‐coated onto glass substrates to prepare the PMMA/BT composite films. The surface modification gave composite films having smooth surfaces and high transparency. An increase in BT particle size and BT volume fraction in the film tended to increase the dielectric constant while keeping the dissipation factor around 5%. The dielectric constant of the film prepared for a particle size of 24.0 nm at 39 vol% attained a value of 19.8 that was around four times higher than that of the pure PMMA film. The dielectric constants of the BT particles estimated by the application of Lichtenecker's mixing model to the composite films were 75.3, 105.1, and 166.3 for particle sizes of 7.8, 11.0, and 24.0 nm, respectively. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers