bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cover Picture: Role of Nanoscale Strain Inhomogeneity on the Light Emission from InGaN Epilayers (Adv. Funct. Mater. 1/2007)
Authors: de Sousa Pereira S. M. , O'Donnell K. P. , da Costa Alves E. J. 
Published: January 2007

AbstractPereira and co‐workers report on p. 37 that nanoscale strain inhomogeneity plays a fundamental role in the spectral properties of InGaN/GaN epilayers. For layers grown above a certain critical thickness, a strong and spatially varying strain profile accompanies a nonplanar surface morphology (as shown on the cover), which is associated with a transition from planar 2D to a Stranski–Krastanow‐like 2D/3D growth mode. Within this framework, apparently disparate experimental observations regarding structural and optical properties, previously reported for InGaN layers, are reconciled.InGaN is the basis of a new generation of light‐emitting devices, with enormous technological potential; it is currently one of the most intensively studied semiconductor materials. It is generally accepted that compositional fluctuations resulting from phase segregation are the origin of the high luminescence efficiency of InGaN. Evidence to show that nanoscale strain inhomogeneity plays a fundamental role in determining the spectral properties of InGaN–GaN heterostructures is reported. For layers above a certain critical thickness, a strong spatially varying strain profile accompanies a nonplanar surface morphology, which is associated with a transition from a planar 2D to a Stranski–Krastanow‐like 2D–3D growth mode; the strong dependence of the critical thickness on the local InN content of the growing films drives a non‐linear growth instability. Within this framework, apparently disparate experimental observations regarding structural and optical properties, previously reported for InGaN layers, are reconciled by a simple phenomenological description.
Visualization of the flow of a fiber suspension through a sudden expansion using PET
Authors: Heath S. J. , Olson J. A. , Buckley K. R. , Lapi S. , Ruth T. J. , Martinez D. M. 
Published: January 2007

AbstractThe motion of 18F radioactively labeled papermaking fibers flowing through an axisymmetric 1:5 sudden expansion has been studied using positron emission tomography (PET). Various length fractions of a mechanical pulp were radioactively labeled and then introduced into a nonradioactive aqueous 0.4 wt. % (consistency) wood pulp suspension. Fully three‐dimensional (3‐D) images were reconstructed both upstream and downstream of the expansion plane for cases in which the upstream velocity U was set from 0.5 to 0.9 m/s (an approximate Reynolds number range of 7,000 to 13,000). Two distinct flow regimes were clearly identified. With U ∼ 0.5 m/s we find that the fiber suspension was not fluidized, and the tracer fibers passed through the expansion as a plug. No mixing was observed between the confined central jet and the static outer region. At larger velocities, we observed that the papermaking suspension was fully fluidized. Our results in this regime indicate that albeit fluidized, concentration inhomogeneities were evident. We find that a particle depletion zone was evident between the central jet, and the recirculating zone resulting from the inlet concentration profile formed in the upstream tube. Particle accumulation was observed in the vortices. No significant differences were observed between the different length tracer fibers. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Identification of neuropeptide Y cleavage products in human blood to improve metabolic stability
Authors: Khan Irfan Ullah , Reppich Regina , Beck‐Sickinger Annette G. 
Published: January 2007

AbstractRegulatory, receptor‐binding peptides are considered as the agents of choice for diagnostic imaging and therapy of cancers, because their receptors are overexpressed in various human cancer cells. It has been recently indicated that there is a putative role of NPY in breast tumors. The expression of the two best‐investigated NPY receptor subtypes, Y1 and Y2, in breast tissue shows predominant occurrence of the Y1 receptor subtype in tumors, whereas Y2 receptors are found in nonproliferative tissue. To investigate the usefulness of NPY analogs for tumor diagnosis and therapy, we investigated the metabolic stability of receptor‐selective NPY analogs in human blood plasma. NPY analogs were synthesized by Fmoc/t‐Bu solid‐phase strategy. Prior to the cleavage of peptides from the resin, they were labeled with 5(6)‐carboxyfluorescein (CF) either at the N‐terminus or at the side chain of Lys4. For the metabolic stability study, the digestion of peptides was monitored by HPLC and the cleavage products were identified by MALDI‐ToF mass spectrometry. The data showed that full‐length [Phe7, Pro34]NPY analogs, which show high binding affinity to Y1 receptors are enzymatically more stable than centrally truncated analogs, which show high binding affinity to Y2 receptors. Furthermore, the N‐terminally CF‐labeled Y1 and Y2 receptor‐selective peptides were found to be enzymatically more resistant than their counterparts containing the CF label at Lys4 side chain. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 88: 182–189, 2007.This article was originally published online as an accepted preprint. The ‘Published Online’ date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Dynamic patterns of neurotrophin 3 expression in the postnatal mouse inner ear
Authors: Sugawara Mitsuru , Murtie Joshua C. , Stankovic Konstantina M. , Liberman M. Charles , Corfas Gabriel 
Published: January 2007

AbstractRecent studies indicate that neurotrophin 3 (NT3) may be important for the maintenance and function of the adult inner ear, but the pattern of postnatal NT3 expression in this organ has not been characterized. We used a reporter mouse in which cells expressing NT3 also express β‐galactosidase, allowing for their histochemical visualization, to determine the pattern of NT3 expression in cochlear and vestibular organs. We analyzed animals from birth (P0) to adult (P135). At P0, NT3 was strongly expressed in supporting cells and hair cells of all vestibular and cochlear sense organs, Reissner's membrane, saccular membrane, and the dark cells adjacent to canal organs. With increasing age, staining disappeared in most cell types but remained relatively high in inner hair cells (IHCs) and to a lesser extent in IHC supporting cells. In the cochlea, by P0 there is a longitudinal gradient (apex > base) that persists into adulthood. In vestibular maculae, staining gradients are: striolar > extrastriolar regions and supporting cells > hair cells. By P135, cochlear staining is restricted to IHCs and their supporting cells, with stronger expression in the apex than the base. By the same age, in the vestibular organs, NT3 expression is weak and restricted to saccular and utricular supporting cells. These results suggest that NT3 might play a long‐term role in the maintenance and functioning of the adult auditory and vestibular systems and that supporting cells are the main source of this factor in the adult. J. Comp. Neurol. 501:30–37, 2007. © 2007 Wiley‐Liss, Inc.
A Highly Stereoselective Divergent Synthesis of Bicyclic Models of Photoreactive Sesquiterpene Lactones
Authors: Fuchs Sébastien , Berl Valérie , Lepoittevin Jean‐Pierre 
Published: January 2007

AbstractSesquiterpene lactones are natural stereochemically pure compounds, which show a number of biological activities. In order to study the reactivity of sesquiterpene lactones in biological systems, we describe herein the asymmetric synthesis of a simple model, the α‐methylene‐hexahydrobenzofuranone 1, which includes the α‐methylene‐γ‐butyrolactone moiety and presents all the different possible ring junctions. Enantioselectivity was obtained by asymmetric palladium‐catalyzed allylic substitution, and diastereoselectivity was achieved by iodolactonization. This strategy afforded the different lactones with an enantiomeric excess of >98 %. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Approaches to Cyclopropazulenes: Transannular Aldol Reactions of Some Derivatives of 1,10‐Dibromobicyclo[8.1.0]undecane‐3,8‐dione
Authors: Payne Alan D. , Skelton Brian W. , Wege Dieter , White Allan H. 
Published: January 2007

AbstractThis paper describes synthetic approaches to potential precursors to cyclopropazulenes, a novel class of nonbenzenoid cycloproparenes. The acid‐catalysed transannular aldol reaction of 1,10‐dibromobicyclo[8.1.0]undecane‐3,8‐dione (10) gives a single ketol 13 possessing the cyclopropane moiety fused to the five‐membered ring. Similar behaviour is observed in the aldol reaction of 27, a benzo‐fused analogue of 10. In the transannular aldol reaction of dione 45, the epoxy bridge forces the reaction in the desired sense to give a ring system (47 and 48) in which the cyclopropane ring is fused to the seven‐membered ring. The α,β‐unsaturated ketone 47 was elaborated into the benzofulvene derivative 51 but conversion of this into the benzocyclopropazulene 58 by overall deoxygenation and debromination could not be achieved. The diones used in this study were generally obtained in good yield by ozonolysis of an appropriate cyclic alkene. In the case of 1a,9a‐dibromo‐1a,2,3,8,9,9a‐hexahydro‐1H‐cycloprop[b]anthracene (26), an alkene possessing methylene groups that are both allylic and benzylic, ozone effected overall dehydrogenation instead of cleavage of the alkene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Primary small cell carcinoma of the pancreas with an unusual sonographic appearance
Authors: Wang Ruei‐Fang , Chou Yi‐Hong , Hwang Jen‐I , Tiu Chui‐Mei , Chiou Hong‐Jen , Chen Siew‐Peng , Chiang Jen‐Huey , Tsay Shy‐Haw , Chang Cheng‐Yen 
Published: January 2007

AbstractWe present a case of primary pancreatic small cell carcinoma with an unusual sonographic feature. A 75‐year‐old woman presented with poor appetite and weight loss. Abdominal sonographic examination revealed a diffusely enlarged pancreas with relative increased echogenicity and smooth contour. CT also confirmed the diffuse infiltrative pattern of the tumor. The diagnosis was confirmed via sonographically guided biopsy. The tumor was composed of small cells with hyperchromatic nuclei and scanty cytoplasm infiltrating the pancreatic tissue, consistent with small cell carcinoma of the pancreas. Primary pancreatic small cell carcinoma rarely presents as the diffuse infiltrating type. These unusual sonographic features must be differentiated from other pancreatic tumors presenting as diffuse pancreatic enlargement. © 2006 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
Ribot, Binet, and the emergence from the anthropological shadow
Authors: Staum Martin S. 
Published: January 2007

AbstractIn the drive to establish a naturalistic psychology in France, anthropological assumptions about a hierarchy of physically determined racial groups with inherent psychological characteristics and about the nearly insurmountable retardation of primitive cultures permeated the work of the founder of French empirical psychology, Théodule Ribot. Assumptions about the correlation of brain mass and head size with intelligence affected Alfred Binet. The rise of sociology and challenges to existing theories of inheritance led Ribot to surrender fitfully some hereditarian assumptions. Binet's experimental caution and contemporary critiques of anthropometry tempered, but did not fully extinguish, his enthusiasm for psychophysical correlations. © 2007 Wiley Periodicals, Inc.
Change‐oriented organizational citizenship behavior: effects of work environment characteristics and intervening psychological processes
Authors: Choi Jin Nam 
Published: January 2007

AbstractOrganizational citizenship behavior (OCB) has attracted major research effort for the last two decades. The vast majority of studies of OCB have been devoted to affiliative forms of such behavior including interpersonal helping, courtesy, and compliance, which are intended to maintain and reinforce the status quo. The present study attends to another form of OCB that challenges the status quo through suggestions for constructive changes in work methods, processes, and policies. This study identifies a set of workplace characteristics that predict change‐oriented OCB. Multi‐level analyses of large‐scale longitudinal data showed that strong vision and innovative climate predicted change‐oriented OCB via both individual‐ and cross‐level processes. These contextual influences were mediated by two intervening variables: psychological empowerment and felt responsibility for change. The results suggest that change‐oriented OCB is significantly predicted by only organizational characteristics. Group‐level dynamics may be less important for understanding challenging types of OCB than for affiliative types such as helping or compliance. Copyright © 2007 John Wiley & Sons, Ltd.
Local application of recombinant human fibroblast growth factor‐2 on bone repair: A dose–escalation prospective trial on patients with osteotomy
Authors: Kawaguchi Hiroshi , Jingushi Seiya , Izumi Toshihiro , Fukunaga Masao , Matsushita Takashi , Nakamura Takashi , Mizuno Kosaku , Nakamura Toshitaka , Nakamura Kozo 
Published: January 2007

AbstractBased on preclinical evidence in animal models, the present study examined the clinical efficacy and safety of recombinant human fibroblast growth factor‐2 (rhFGF‐2) to accelerate bone repair in a dose‐escalation prospective trial. One of three dosages (200, 400 or 800 µg) of rhFGF‐2 in a biodegradable gelatin hydrogel was injected during surgery into the osteotomy site of 59 knee osteoarthritis patients undergoing high tibial osteotomy, and 57 of them were monitored for 16 weeks. The rhFGF‐2 dose dependently increased the percentage of patients with radiographic bone union, and decreased the average time needed for such union. The percentages of patients with an absence of pain and full‐weight bearing were also greater in the higher dosage groups than in the low dosage group, especially in the clinically critical periods 6, 8, and 10 weeks. Neither blood chemistries nor clinical adverse events were associated with the rhFGF‐2 dosages. We therefore conclude that the rhFGF‐2 in gelatin hydrogel dose dependently accelerated radiographic bone union of a surgical osteotomy with a safety profile at least at the dosages used, suggesting the clinical efficacy of this agent for bone repair. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:480–487, 2007
Expanding the enantioselectivity of the gas‐chromatographic chiral stationary phase Chirasil‐Val‐C11 by doping it with octakis(3‐O‐butanoyl‐2,6‐di‐O‐n‐pentyl)‐γ‐cyclodextrin
Authors: Levkin Pavel A. , Levkina Anna , Czesla Harri , Nazzi Samuele , Schurig Volker 
Published: January 2007

AbstractCombination of the enantioselective properties of the two versatile gas‐chromatographic chiral stationary phases (CSPs) octakis(3‐O‐butanoyl‐2,6‐di‐O‐n‐pentyl)‐γ‐CD (Lipodex E) 1 and L‐valine‐diamide‐based CSP Chirasil‐Val‐C11 2 has been realized by doping the chiral polymer 2 with the nonpolymeric selector 1. The resulting mixed‐mode CSP Chirasil‐Val(γ‐Dex) 3 was found to have a greatly improved enantioselectivity toward proline and aspartic acid (as N‐trifluoroacetyl ethyl or methyl esters) in comparison to the single‐mode CSP 2. The presence of the CD selector in 3 extended the scope of gas‐chromatographic enantioseparations achievable on 2 to underivatized alcohols, terpenes, and other chiral compounds that are exclusively enantioseparated on 1.
A comprehensive kinetic mechanism for CO, CH2O, and CH3OH combustion
Authors: Li Juan , Zhao Zhenwei , Kazakov Andrei , Chaos Marcos , Dryer Frederick L. , Scire James J. 
Published: January 2007

AbstractNew experimental profiles of stable species concentrations are reported for formaldehyde oxidation in a variable pressure flow reactor at initial temperatures of 850–950 K and at constant pressures ranging from 1.5 to 6.0 atm. These data, along with other data published in the literature and a previous comprehensive chemical kinetic model for methanol oxidation, are used to hierarchically develop an updated mechanism for CO/H2O/H2/O2, CH2O, and CH3OH oxidation. Important modifications include recent revisions for the hydrogen–oxygen submechanism (Li et al., Int J Chem Kinet 2004, 36, 565), an updated submechanism for methanol reactions, and kinetic and thermochemical parameter modifications based upon recently published information. New rate constant correlations are recommended for CO + OH = CO2 + H (R23) and HCO + M = H + CO + M (R24), motivated by a new identification of the temperatures over which these rate constants most affect laminar flame speed predictions (Zhao et al., Int J Chem Kinet 2005, 37, 282). The new weighted least‐squares fit of literature experimental data for (R23) yields k23 = 2.23 × 105T1.89exp(583/T) cm3/mol/s and reflects significantly lower rate constant values at low and intermediate temperatures in comparison to another recently recommended correlation and theoretical predictions. The weighted least‐squares fit of literature results for (R24) yields k24 = 4.75 × 1011T0.66exp(−7485/T) cm3/mol/s, which predicts values within uncertainties of both prior and new (Friedrichs et al., Phys Chem Chem Phys 2002, 4, 5778; DeSain et al., Chem Phys Lett 2001, 347, 79) measurements. Use of either of the data correlations reported in Friedrichs et al. (2002) and DeSain et al. (2001) for this reaction significantly degrades laminar flame speed predictions for oxygenated fuels as well as for other hydrocarbons. The present C1/O2 mechanism compares favorably against a wide range of experimental conditions for laminar premixed flame speed, shock tube ignition delay, and flow reactor species time history data at each level of hierarchical development. Very good agreement of the model predictions with all of the experimental measurements is demonstrated. © 2007 Wiley Periodicals, Inc. 39: 109–136, 2007
Cost-Effectiveness of Screening for Hepatopulmonary Syndrome in Liver Transplant Candidates†
Authors: Roberts Neil D. , Arguedas Miguel R. , Fallon Michael B. 
Published: January 2007

Abstract

The hepatopulmonary syndrome (HPS) is present in 15–20% of patients with cirrhosis undergoing orthotopic liver transplantation (OLT) evaluation. Both preoperative and post-OLT mortality is increased in HPS patients particularly when hypoxemia is severe. Screening for HPS could enhance detection of OLT candidates with sufficient hypoxemia to merit higher priority for transplant and thereby decrease mortality. However, the cost-effectiveness of such an approach has not been assessed. Our objective was to perform a cost-effectiveness analysis from a third-party payer's perspective of screening for HPS in liver OLT candidates. The costs and outcomes of 3 different strategies were compared: (1) no screening, (2) screening patients with a validated dyspnea questionnaire, and (3) screening all patients with pulse oximetry. Arterial blood gas analyses and contrast echocardiography were performed in patients with dyspnea or a pulse oximetry (SpO2) ≤97% to define the presence of HPS. A Markov model was constructed simulating the natural history of cirrhosis in a cohort of patients 50 years old over a time horizon of their remaining life expectancy. Transition probabilities were obtained from published data available through Medline and U.S. vital statistics. Costs represented Medicare reimbursement data at our institution. Costs and health effects were discounted at a 3% annual rate. No screening was associated with a total cost of $291,898 and a life expectancy of 11.131 years. Screening with pulse oximetry was associated with a cost of $299,719 and a life expectancy of 12.27 years. Screening patients with the dyspnea-fatigue index was associated with a cost and life expectancy of $300,278 and 12.28 years, respectively. The incremental cost-effectiveness ratio of screening with pulse oximetry (compared to no screening) was $6,867 per life year gained, whereas that of the dyspnea-fatigue index (compared to pulse oximetry) was $55,900 per life year gained. The cost-effectiveness of screening depended on the prevalence and severity of HPS, and the choice of screening strategy was dependent on the sensitivity of the screening modality. In conclusion, screening for HPS, especially with pulse oximetry, is a cost-effective strategy that improves survival in transplant candidates predominantly by targeting the transplant to the subgroup of patients most likely to benefit. The utility of screening depends on the prevalence and severity of HPS in the target population. Liver Transpl, 2006. © 2006 AASLD.
Ulnar nerve repair by end‐to‐side neurorrhaphy on the median nerve with interposition of a vein: An experimental study
Authors: Manasseri Benedetto , Raimondo Stefania , Geuna Stefano , Risitano Giovanni , D'alcontres Francesco Stagno 
Published: January 2007

AbstractOur study used a rat animal model to verify that Schwann cell migration, collateral axonal sprouting, and regeneration were not hindered by interposition of a 10‐mm vein segment between the distal stump of the transected ulnar nerve and the donor median nerve in end‐to‐side reconstruction. Reconstructed nerves were withdrawn at 7, 14, 30, and 60 days after surgery, then analyzed by confocal laser microscopy after immunolabeling with anti‐neurofilament‐200 kD (an axonal marker) and anti‐S100 (a glial marker) antibodies. Results are reported at 7, 14, 30, and 60 days after surgery. Our observations indicate that chemotactic factors that stimulate end‐to‐side nerve regeneration can exert their action at this distance. These findings suggest a possible clinical application for this surgical technique in cases when the severed nerve stump is far from the potential donor nerve. © 2007 Wiley‐Liss, Inc. Microsurgery, 2007.
Secondary structure length as a determinant of folding rate of proteins with two‐ and three‐state kinetics
Authors: Huang Ji‐Tao , Cheng Jin‐Pei , Chen Hui 
Published: January 2007

AbstractWe present a simple method for determining the folding rates of two‐ and three‐state proteins from the number of residues in their secondary structures (secondary structure length). The method is based on the hypothesis that two‐ and three‐state foldings share a common pattern. Three‐state proteins first condense into metastable intermediates, subsequent forming of α‐helices, turns, and β‐sheets at slow rate‐limiting step. The folding rate of such proteins anticorrelate with the length of these β‐secondary structures. It is also assumed that in two‐state folding, rapidly folded α‐helices and turns may facilitate formation of fleeting unobservable “intermediates” and thus show two‐state behavior. There is an inverse relationship between the folding rate and the length of β‐sheets and loops. Our study achieves 94.0 and 88.1% correlations with folding rates determined experimentally for 21 three‐ and 38 two‐state proteins, respectively, suggesting that protein‐folding rates are determined by the secondary structure length. The kinetic kinds are selected on the basis of a competitive formation of hydrophobic collapse and α‐structure in early intermediates. Proteins 2007. © 2007 Wiley‐Liss, Inc.