bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxidation of methyl and ethyl butanoates
Authors: Hakka M. H. , Bennadji H. , Biet J. , Yahyaoui M. , Sirjean B. , Warth V. , Coniglio L. , Herbinet O. , Glaude P. A. , Billaud F. , Battin‐Leclerc F. 
Published: February 2010

AbstractThis paper describes an experimental and modeling study of the oxidation of methyl and ethyl butanoates in a shock tube. The ignition delays of these two esters mixed with oxygen and argon for equivalence ratios from 0.25 to 2 and ester concentrations of 0.5% and 1% were measured behind a reflected shock wave for temperatures from 1250 to 2000 K and pressures around 8 atm. To extend the range of studied temperatures in the case of methyl butanoate, two sets of measurements were also made in a jet‐stirred reactor at 800 and 850 K, at atmospheric pressure, at residence times varying between 1.5 and 9 s and for equivalence ratios of 0.5 and 1. Detailed mechanisms for the combustion of methyl and ethyl butanoates have been automatically generated using a version of EXGAS software improved to take into account these oxygenated reactants. These mechanisms have been validated through comparison of simulated and experimental results in both types of reactor. The main reaction pathways have been derived from reaction flux and sensitivity analyses performed at different temperatures. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 226–252, 2010
Kinetic study of the reaction of dimethyl carbonate with trialkylamines
Authors: Weisshaar Duane E. , Earl Gary W. , Villa Eric M. , Zierke Jessica L. (Paumen) , Fry Christopher J. , Becvar Kara L. , Li Shik Ki , Schafer Matthew C. 
Published: February 2010

AbstractQuaternary ammonium compounds are produced worldwide in hundreds of millions of pound volume annually for a plethora of end‐uses from fabric‐care formulations to asphalt emulsifiers, typically from nongreen alkylating reagents. The kinetics of a reaction employing dimethyl carbonate (DMC) as a green alkylating agent was investigated using three trialkylamines (tributylamine, trihexylamine, and trioctylamine) at several temperatures. Arrhenius and Eyring analysis of the data showed that values of Ea (79 kJ/mol), ΔH‡ (75 kJ/mol), and ΔS‡ (220 J/(mol K)) were the same for all three amine reactants, consistent with a report that Ea is independent of alkyl chain length when the chain length is greater than three carbons. Although rates are significantly slower with DMC than with other alkylating reagents, the resulting methyl carbonate anion has advantages for clean anion metathesis, which is important for some applications, especially those involving ionic liquids. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 221–225, 2010
Mentorship in otolaryngology residency: The resident perspective
Authors: Hsu Amy K , Tabaee Abtin , Persky Mark S. 
Published: February 2010

AbstractObjectives/Hypothesis:To assess the current state of mentorship in otolaryngology residency.Study Design:Internet‐based anonymous survey of chief residents in otolaryngology residency.Methods:Nonidentifying demographic information, career plans, and general questions about residency experience were queried. Participants were asked to rate their mentorship experience in general and specifically with regard to research, personal quality of life, and career preparation. Responses were scored using a five‐point ordinal Likert scale, with higher scores representing more favorable responses.Results:The survey was completed by 47 (17.2%) respondents. Eighteen respondents (38%) were assigned an official faculty mentor, and 23 respondents (49%) were assigned a research mentor during their residency. Thirty‐nine respondents (83%) reported receiving meaningful mentorship from faculty who were not officially assigned mentors. Overall, 18 respondents (38%) were neutral or not satisfied with the mentorship they received during residency. Statistically significant higher scores were noted for mentorship in career preparation (median, 4) versus mentorship in research (median, 4; P < .001) and resident quality of life (median, 3; P < .001). Lower scores were noted for availability of mentorship in preparation for a career in private practice versus academic medicine (median, 4 vs. 5; P < .001). Residents who were officially assigned mentors reported statistically significant higher scores with regard to satisfaction with the overall mentorship experience (median, 4 vs. 3; P = .05) and different aspects of mentorship in career preparation and research training.Conclusions:The current study reveals variability in the mentorship experience in otolaryngology residency. Potential deficiencies may exist, including absence of formal mentorship in some residency programs. Increased attention to mentorship, especially with regard to research, career preparation, and quality of life may improve the overall residency experience.
Ulvan as a New Type of Biomaterial from Renewable Resources: Functionalization and Hydrogel Preparation
Authors: Morelli Andrea , Chiellini Federica 
Published: February 2010

AbstractUlvan, a sulfated cell‐wall polysaccharide extracted from green seaweeds, is functionalized by grafting methacryloyl moieties as a radical polymerizable group and photopolymerized under UV irradiation in order to attain biodegradable hydrogels. The functionalization reaction is carried out by using methacrylic anhydride or glycidyl methacrylate according to two basic procedures applied to polysaccharides. The functionalization of Ulvan is determined by FT‐IR and 1H NMR spectroscopy and confirmed by DSC analysis. Hydrogels were characterized by FT‐IR and by 1H NMR spectroscopies and their swelling behaviour assessed in terms of degree of swelling using PBS 1 × pH 7.4 as a medium in order to check their stability under physiological conditions.magnified image
Correction: Amino acid metabolism of bovine blastocysts: A biomarker of sex and viability
Authors: Sturmey R.G. , Bermejo‐Alvarez P. , Gutierrez‐Adan A. , Rizos D. , Leese H.J. , Lonergan P. 
Published: February 2010

AbstractIn the recently published article “Amino acid metabolism of bovine blastocysts: A biomarker of sex and viability” by R. Sturmey et al. (Mol Reprod Dev, volume 77 (3): 285–296, 2010 [DOI: 10.1002/mrd.21145]), the Acknowledgment of grant support was inadvertently omitted.The omitted text is herein printed to address this error: RGS wishes to acknowledge financial support from a Wellcome Trust VIP Fellowship, administered by the Biology Department of the University of York. HJL wishes to acknowledge financial support from The Leverhulme Trust.
Abdominal undifferentiated small round cell tumor with unique translocation (X;19)(q13;q13.3)
Authors: Yustein Jason T. , Rednam Surya , Bertuch Alison A. , Goss John A. , Brandt Mary L. , Eldin Karen , Lu Xinyan , Hicks John 
Published: February 2010

AbstractWe describe a male with a large abdominal mass, most likely originating from the liver, with capsule rupture and tumor dissemination into the abdominal cavity. Adherence of the tumor to the diaphragm and lower right colon also were noted. A comprehensive evaluation of the mass revealed no tumor‐defining histopathologic, immunocytochemical, ultrastructural, cytogenetic, or translocation features. The malignant tumor was found to have a novel translocation (X;19)(q13;13.3), which has not been reported in small round cell tumors of childhood or adults. The final diagnosis rendered was an undifferentiated small round cell tumor of uncertain cell of origin. Pediatr Blood Cancer 2010;54:1041–1044 © 2010 Wiley‐Liss, Inc.
Synthesis of nano β‐TCP and the effects on the mechanical and biological properties of β‐TCP/HDPE/UHMWPE nanocomposites
Authors: Abadi M. Bagheri Hossein , Ghasemi I. , Khavandi A. , Shokrgozar M.A. , Farokhi M. , Homaeigohar S.Sh. , Eslamifar A. 
Published: February 2010

AbstractHigh density polyethylene/tricalcium phosphate/ultra high molecular weight polyethylene (TCP/HDPE/UHMWPE) Nanocomposite as an orthopedic biomaterial (with better properties toward TCP/HDPE composite) was obtained. To evaluate the capability of this nanocomposite as a material for bone tissue replacement, mechanical and biological assessments were performed. In this study, nanosize β‐TCP powders with average grain size of 100 nm were synthesized by chemical precipitation method and characterized by means of X‐ray diffraction (XRD), Fourier‐transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). To evaluate the mechanical properties of this biomaterial, tensile properties were obtained for the material. Results showed that by increasing the weight percentage of β‐TCP, the elastic modulus increases, elongation at yield decreases and with no significant change in tensile strength. SEM micrographs of cryogenic fracture surface of samples indicated that distribution of nano powders in matrix is homogeneous. In vitro biological evaluations on the samples were done by performing cytotoxicity (MTT assay), alkaline phosphatase enzyme, and cell attachment tests. In all of the tests, osteoblast cells were used. Results of biological tests showed that the samples are biocompatible and they have no toxicity. Also, SEM observations demonstrated that the cells can attach to surface of nanocomposite samples, which reveals osteoconductivity of the surface. POLYM. COMPOS., 31:1745–1753, 2010. © 2010 Society of Plastics Engineers.
Identification of Neospora caninum proteins regulated during the differentiation process from tachyzoite to bradyzoite stage by DIGE
Authors: Marugán‐Hernández Virginia , Álvarez‐García Gema , Risco‐Castillo Verónica , Regidor‐Cerrillo Javier , Ortega‐Mora Luis Miguel 
Published: February 2010

AbstractIdentification of differentially expressed proteins during Neospora caninum tachyzoite–bradyzoite conversion processes may lead to a better knowledge of the pathogenic mechanisms developed by this important parasite of cattle. In the present work, a differential expression proteomic study of tachyzoite and bradyzoite stages was accomplished for the first time by applying DIGE technology coupled with MS analysis. Up to 72 differentially expressed spots were visualized (1.5‐fold in relative abundance, p<0.05, t‐test). A total of 53 spots were more abundant in bradyzoites and 19 spots in tachyzoites. MS analysis identified 26 proteins; 20 of them overexpressed in the bradyzoite stage and 6 in the tachyzoite stage. Among the novel proteins, enolase and glyceraldehyde‐3‐phosphate dehydrogenase (involved in glycolysis), HSP70 and HSP90 (related to stress response) as well as the dense granule protein GRA9, which showed higher abundance in the bradyzoite stage, might be highlighted. On the other hand, isocitrate dehydrogenase 2, involved in the Krebs cycle, was found to be more abundant in tachyzoites extract. Biological functions from most novel proteins were correlated with previously reported processes during the differentiation process in Toxoplasma gondii. Thus, DIGE technology arises as a suitable tool to study mechanisms involved in the N. caninum tachyzoite to bradyzoite conversion.
Noncollagenous region of the streptococcal collagen‐like protein is a trimerization domain that supports refolding of adjacent homologous and heterologous collagenous domains
Authors: Yu Zhuoxin , Mirochnitchenko Oleg , Xu Chunying , Yoshizumi Ayumi , Brodsky Barbara , Inouye Masayori 
Published: February 2010

AbstractProper folding of the (Gly‐Xaa‐Yaa)n sequence of animal collagens requires adjacent N‐ or C‐terminal noncollagenous trimerization domains which often contain coiled‐coil or beta sheet structure. Collagen‐like proteins have been found recently in a number of bacteria, but little is known about their folding mechanism. The Scl2 collagen‐like protein from Streptococcus pyogenes has an N‐terminal globular domain, designated Vsp, adjacent to its triple‐helix domain. The Vsp domain is required for proper refolding of the Scl2 protein in vitro. Here, recombinant Vsp domain alone is shown to form trimers with a significant α‐helix content and to have a thermal stability of Tm = 45°C. Examination of a new construct shows that the Vsp domain facilitates efficient in vitro refolding only when it is located N‐terminal to the triple‐helix domain but not when C‐terminal to the triple‐helix domain. Fusion of the Vsp domain N‐terminal to a heterologous (Gly‐Xaa‐Yaa)n sequence from Clostridium perfringens led to correct folding and refolding of this triple‐helix, which was unable to fold into a triple‐helical, soluble protein on its own. These results suggest that placement of a functional trimerization module adjacent to a heterologous Gly‐Xaa‐Yaa repeating sequence can lead to proper folding in some cases but also shows specificity in the relative location of the trimerization and triple‐helix domains. This information about their modular nature can be used in the production of novel types of bacterial collagen for biomaterial applications.
Structural insights into the molecular mechanism of H‐NOX activation
Authors: Olea Charles , Herzik Mark A. , Kuriyan John , Marletta Michael A. 
Published: February 2010

AbstractNitric oxide (NO) signaling in mammals controls important processes such as smooth muscle relaxation and neurotransmission by the activation of soluble guanylate cyclase (sGC). NO binding to the heme domain of sGC leads to dissociation of the iron–histidine (Fe–His) bond, which is required for enzyme activity. The heme domain of sGC belongs to a larger class of proteins called H‐NOX (Heme‐Nitric oxide/OXygen) binding domains. Previous crystallographic studies on H‐NOX domains demonstrate a correlation between heme bending and protein conformation. It was unclear, however, whether these structural changes were important for signal transduction. Subsequent NMR solution structures of H‐NOX proteins show a conformational change upon disconnection of the heme and proximal helix, similar to those observed in the crystallographic studies. The atomic details of these conformational changes, however, are lacking in the NMR structures especially at the heme pocket. Here, a high‐resolution crystal structure of an H‐NOX mutant mimicking a broken Fe–His bond is reported. This mutant exhibits specific changes in heme conformation and major N‐terminal displacements relative to the wild‐type H‐NOX protein. Fe–His ligation is ubiquitous in all H‐NOX domains, and therefore, the heme and protein conformational changes observed in this study are likely to occur throughout the H‐NOX family when NO binding leads to rupture of the Fe–His bond.
Neutral Higgs boson pair production at Linear Colliders
Authors: Solà J. , López‐Val D. 
Published: February 2010

AbstractWe compute the one‐loop production cross section for neutral Higgs boson pairs at linear colliders from a generic two‐Higgs‐doublet model (2HDM). We identify important quantum effects associated to the triple‐Higgs boson self‐interactions – a genuine feature of the 2HDM, which is impossible to achieve in the Minimal Supersymmetric Standard Model (MSSM).
An ancient anion‐binding structural module in RNA and DNA helicases
Authors: Milner‐White E. James , Pietras Zbigniew , Luisi Ben F. 
Published: February 2010

AbstractRNA and DNA helicases manipulate or translocate along single strands of nucleic acids by grasping them using a conserved structural motif. We have examined the available crystal structures of helicases of the two principal superfamilies, SF1 and SF2, and observed that the most conserved interactions with the nucleic acid occur between the phosphosugar backbone of a trinucleotide and the three strand‐helix loops within a (β‐strand/α‐helix)3 structural module. At the first and third loops is a conserved hydrogen‐bonded feature called a thr‐motif, often seen at α‐helical N‐termini, with the threonine as the N‐cap residue. These loops can be aligned with few insertions or deletions, and their main chain atoms are structurally congruent amongst the family members and between the two modules found as tandem pairs in all SF1 and SF2 proteins. The other highly conserved interactions with nucleic acid involve mainchain NH groups, often at the helical N‐termini, interacting with phosphate groups. We comment on how the sequence motifs that are commonly used to identify helicases map to locations on the module and discuss the implications of the conserved orientation of nucleic acid on the surface of the module for directional stepping along DNA or RNA. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Researching illegality and labour migration
Authors: Anderson Bridget , Ruhs Martin 
Published: February 2010

AbstractThis introduction to thePopulation, Space and PlaceSpecial Issue ‘Researching illegality and labour migration: the research/policy nexus’, considers what is meant by ‘illegal immigration’. This is of key importance to both policy and academic discussion, and contradictions and debates are evidenced in the terminology (‘illegal’, ‘irregular’, ‘undocumented’, etc.) deployed. The paper briefly reviews current academic literature and situates the issue's contributions within this. It concludes by drawing attention to migrant agency and its relation to labour markets and migratory networks. Copyright © 2010 John Wiley & Sons, Ltd.
Domains in helicoidal magnetic structure
Authors: Rosenfeld E. V. 
Published: February 2010

AbstractTheoretical investigation of the magnetic spiral behavior in a layered magnet with strong hexagonal magnetic anisotropy has been performed. It is shown that if the exchange integrals between the first and second neighboring layers meet the requirement |J1| = −J2, the energy densities for spirals with three and four (at J1 < 0) or four and six (at J1 > 0) layers in the period coincide. Moreover, near the surface of contact of the above phases the energy density is equal to or even lower than inside each of them, which should result in the appearance of a domain magnetic structure.magnified image
Ferromagnetic quantum phase transition in Sr1−xCaxRuO3 thin films
Authors: Schneider M. , Moshnyaga V. , Gegenwart P. 
Published: February 2010

AbstractThe ferromagnetic (FM) quantum phase transition in the perovskite ruthenate Sr1−xCaxRuO3 is studied by low‐temperature magnetization and electrical resistivity measurements on thin films. The films were grown epitaxially on SrTiO3 substrates using metalorganic aerosol deposition and characterized by X‐ray diffraction and room temperature scanning tunneling microscopy. High residual resistivity ratios of 29 and 16 for $x = 0$ and $1$, respectively, prove the high quality of the investigated samples. We observe a continuous suppression of the FM Curie temperature from $T_{\rm C} = 160\,{\rm K}$ at $x = 0$ towards $T_{\rm C} \to 0$ at $x_{\rm c} \approx 0.8$. The analysis of the electrical resistivity between 2 and 10 K reveals T2 and T3/2 behavior at $x \leq 0.6$ and $x \geq 0.7$, respectively. For undoped CaRuO3, the measurement has been extended down to 60 mK, revealing a crossover to T2 behavior around 2 K, which suggests a Fermi‐liquid ground state in this system.
Quasi one‐dimensional chains and exciton–phonon interactions in TiSe2
Authors: van Wezel J. , Nahai‐Williamson P. , Saxena S.S. 
Published: February 2010

AbstractIn charge ordered materials such as the transition metal dichalcogenides, in which the lattice modes are strongly coupled to the charges, the critical fluctuations surrounding a quantum critical point will consist of slow charge modulations as well as soft phonons. The presence of both these types of fluctuations offers an excellent opportunity for novel phases and unconventional forms of supercondictivity to arise. One such material, TiSe2, has been found to superconduct upon intercalation of copper [Morosan et al., Nature Phys. 2, 544 (2006)], with a concomitant suppression of CDW order. The transition is driven by an imbalance of charge carriers, leading to conventional superconductivity. Very recently however, Kusmartseva et al. [Phys. Rev. Lett. 103, 236401 (2009)] also discovered superconductivity in the pure system under pressure. This finding cannot be explained solely by the an imbalance of charge carriers and hints at the possibility of exciton‐mediated superconductivity made manifest in a clean experimental system. Here we analyze the electronic structure of TiSe2 using a tight binding model to fit its band structure. The resulting values found for the various overlap integrals in this material strongly suggest that TiSe2 is best viewed as a system of weakly linked one‐dimensional chains. We argue that in these chains excitons and Jahn–Teller phonons will strongly interact, and that it is therefore likely that both the charge density wave transition and the superconductivity which arises upon suppression of the CDW phase are driven by excitonic as well as phononic modes.
Quantum criticality in CePt1−xNix due to hydrostatic and chemical pressure
Authors: Bagrets Nadezda , Fritsch Veronika , Grube Kai , Löhneysen Hilbert v. 
Published: February 2010

AbstractWe have investigated the possibility of tuning ferromagnetic CePt1−xNix for $x = 0.85$ and 0.9 to a quantum critical point (QCP) by measuring the magnetization between 2 and 300 K on polycrystals under pressures up to 13 kbar. Thus we constructed a TC–p phase diagram for CePt1−xNix with $x = 0.85$. For the alloy with $x = 0.9$ we show that the ferromagnetic hysteresis loop at 2.5 K is completely suppressed by a hydrostatic pressure of 10.2 kbar. Our findings suggest that Ce(Pt:Ni) can be tuned to the QCP with the application of hydrostatic pressure at considerably lower pressures than pure CePt.
Inhibitory effects of curcumenol on human liver cytochrome P450 enzymes
Authors: Sun Dong‐Xue , Fang Zhong‐Ze , Zhang Yan‐Yan , Cao Yun‐Feng , Yang Ling , Yin Jun 
Published: February 2010

AbstractCurcumenol, one of the major components of Zedoary turmeric oil, has been widely used to treat cancer and inflammation. As an antibiotic or anticancer drug, curcumenol is highly likely to be used in combination with various synthetic drugs in most cases, thus it is necessary to evaluate potential pharmacokinetic drug‐drug interactions induced by curcumenol. In this study, the inhibitory effects of curcumenol on seven CYP isoforms were investigated, and the results demonstrated that only CYP3A4 was strongly inhibited (IC50 = 12.6 ± 1.3 μM). Kinetic analysis showed the inhibition type was competitive with Ki value of 10.8 μM. Time‐ and NADPH‐dependent inhibitions were also investigated to show curcumenol is not a mechanism‐based inhibitor. Employing these in vitro data and maximum plasma concentration of curcumenol in human predicted from beagle dog's in vivo pharmacokinetic data, the change in AUC of victim drugs was predicted to be 0.4%, which suggested that curcumenol may be safely used without inducing metabolic drug‐drug interaction through P450 inhibition. Nevertheless, due to the limited pharmacokinetic data available for curcumenol in humans, it is still not possible to evaluate its potential clinical effects on human patients from in vitro data. Thus, the magnitude of drug‐drug interaction (DDI) induced by curcumenol warrants further investigation. Copyright © 2010 John Wiley & Sons, Ltd.