bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hochauflösende Analyse der Diffusion in Metallen: Anwendung der Sekundärionen‐Massenspektrometrie auf maßgeschneiderte Proben
Authors: Macht M.‐P. , Naundorf V. 
Published: February 2013

AbstractDie Kombination von hochauflösender Schichtentrennung durch Ionenzerstäubung und empfindlicher Konzentrationsmessung durch Sekundärionen‐Massenspektrometrie (SIMS) erlaubt die Messung kleinster Diffusionseffekte. Nach einer kurzen Beschreibung der Meßmethode werden die wichtigsten methodenspezifischen Effekte, die SIMS‐Messungen erschweren und ihre Auflösung begrenzen, anhand einiger Beispiele vorgestellt. Es wird gezeigt, daß die Anwendung der Methode erst bei Verwendung maßgeschneiderter Proben erfolgreich ist. Aufbau und Herstellungsverfahren solcher Proben werden beschrieben und beispielhafte Meßergebnisse erläutert.
Physikunterricht in Europa
Authors: Born Gernot , Wickihalter Rolf 
Published: February 2013

AbstractIm Auftrag des Advisory Committee Physics Education (ACPE) der Europäischen Physikalischen Gesellschaft (EPS) wurden Umfang, Stundenanteile, didaktische Leitideen, methodische Konzeptionen des Physikunterrichts in Europa analysiert. Die Untersuchung belegt, daß in der hochindustrialisierten Bundesrepublik Deutschland ein Schüler im Sekundarbereich einerseits wahlweise bis zu 11% seiner gesamten Unterrichtsstunden im Fach Physik hat, andererseits aber auch schon mit erschreckenden 2% sein Abitur bekommen kann.
Vierter Tag der DPG: Welche Bedeutung hat die physikalische Forschung für unsere Gesellschaft?: Forschung im Spiegel des gesellschaftlichen Wertesystems
Authors: Lehr G. 
Published: February 2013

AbstractDie schon traditionelle Diskussionsveranstaltung am „Tag der DPG”︁ war der Bedeutung der physikalischen Forschung für unsere Gesellschaft gewidmet. Dieses Thema behandelten aus der Sicht des Forschungspolitikers Herr Ministerialdirektor Dr. G. Lehr vom Bundesforschungsministerium, von der Warte eines Verantwortlichen in der Industrie Herr Dr. Dr. F. Laußermair, für Forschung zuständiges Vorstandsmitglied von MAN Augsburg, und vom Standpunkt des Wissenschaftstheoretikers Herr Professor Dr. J. Mittelstraß, Philosophische Fakultät der Universität Konstanz. Im folgenden sind diese Referate wiedergegeben (zum Teil gekürzt bzw. zusammengefaßt). Die Diskussion war unterteilt in Beiträge unmittelbar im Anschluß an die Referate und in eine allgemeine Aussprache am Ende der Veranstaltung. Für die Berichterstattung hier schien es zweckmäßig, die wichtigsten Diskussionsbeiträge thematisch zu ordnen und jeweils dem Referat nachzustellen, auf das sie sich beziehen.
Novel thermoresponsive fluorinated double‐hydrophilic poly{[N‐(2,2‐difluoroethyl)acrylamide]‐b‐[N‐(2‐fluoroethyl)acrylamide]} block copolymers
Authors: Bak Jae Min , Lee Hyung‐il 
Published: February 2013

AbstractNovel thermoresponsive double‐hydrophilic fluorinated block copolymers were successfully synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization. Poly[N‐(2,2‐difluoroethyl)acrylamide] (P2F) was synthesized via RAFT polymerization of N‐(2,2‐difluoroethyl)acrylamide (M2F) using 2‐dodecylsulfanylthiocarbonylsulfanyl‐2‐methylpropionic acid (DMP) as the chain transfer agent (CTA) and 2,2′‐azobisisobutyronitrile (AIBN) as the initiator. The resulting P2F macroCTA was further chain extended with N‐(2‐fluoroethyl)acrylamide (M1F) to yield poly{[N‐(2,2‐difluoroethyl)acrylamide]‐b‐[N‐(2‐fluoroethyl)acrylamide]} (P2F‐b‐P1F) block copolymers with different lengths of the P1F block. Molecular weight and molecular weight distribution were determined by gel permeation chromatography. The average molecular weight (Mn) of the resulting polymers ranged from 2.9 × 104 to 5.8 × 104 depending on the length of the P1F block. The molecular weight distribution was low (Mw/Mn = 1.11–1.19). Turbidimetry by UV‐Visble (UV‐Vis) spectroscopy, dynamic light scattering, and in situ temperature‐dependent 1H NMR measurements demonstrated that the P2F block underwent a thermal transition from hydrophilic to hydrophobic, which in turn induced self‐assembly from unimers to aggregates. Transmission electron microscopy studies demonstrated that polymeric aggregates formed from an aqueous solution of P2F‐b‐P1F at 60 °C were disrupted by cooling down to 20 °C and regenerated by heating to 60 °C. Temperature‐triggered release of a model hydrophobic drug, coumarin 102, was also demonstrated. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Electronic states in antiferromagnet UCd11 and reference compound ThCd11: studied by the de Haas–van Alphen effect
Authors: Hirose Yusuke , Miura Yasunao , Tsutsumi Hiroki , Yoshiuchi Shingo , Ohya Masahiro , Sugiyama Kiyohiro , Takeuchi Tetsuya , Yamagami Hiroshi , Yamamoto Etsuji , Haga Yoshinori , Settai Rikio , Ōnuki Yoshichika 
Published: February 2013

AbstractWe carried out the de Haas–van Alphen (dHvA) experiment for an antiferromagnet UCd11 and its non‐5f reference compound ThCd11 to clarify the Fermi surface properties and the true electronic specific‐heat coefficient γ of UCd11. We observed dHvA signals of both compounds and compared the experimental results with the result of theoretical band calculations. The Fermi surfaces of both compounds are found to be small and closed. The cyclotron masses obtained from the dHvA data of UCd11 are compared with those of reference compounds ThCd11, NpCd11, and LaCd11, and the γ value of UCd11 is estimated to be about 100 mJ K−2 mol−1, which is much smaller than the 840 mJ K−2 mol−1 in the previous reports. It is concluded that this large value is mainly not due to heavy quasiparticles but due to the magnetic contribution to the specific heat.
Steady‐state random walk on connected graph of arbitrary topology with random and non‐symmetric transition rates
Authors: Taraskin S. N. 
Published: February 2013

Abstractmagnified imageThe general solution and its graphical interpretation for the stationary occupation probability of nodes for a random‐walk on a connected network of arbitrary topology with random and non‐symmetric transition rates are presented. Configurational averaging over the quenched random transition rates is performed for several simple networks: open chains, simple and general stars, two interacting stars. It is demonstrated that disorder in transition rates for a random walker induces variable occupation probability for different nodes in the network depending on their location. The boundary nodes are shown to be occupied with higher probability than the central ones.
The boson peak
Authors: Schirmacher Walter 
Published: February 2013

Abstractmagnified imageThe vibrational properties of glasses in the THz range differ very much from what is expected from Debye's elasticity theory: the density of states (DOS) deviates from Debye's ω2 law [the “boson peak” (BP)], the sound velocity shows a negative dispersion in the BP frequency regime and there is a strong increase in the sound attenuation near the BP frequency. These anomalies are related to an anomalous temperature dependence of the specific heat and thermal conductivity in the 10 K regime. An overview of the heterogeneous‐elasticity theory is given, by means of which all these anomalies can be explained and shown to arise from the structural disorder, leading to spatial fluctuations of the shear modulus. Further, a very general model‐independent explanation of the BP‐related anomalies, based solely on symmetry arguments, is given.
Phase separation in InxGa1‐xN (0.10 < x < 0.40)
Authors: Belyaev K. G. , Rakhlin M. V. , Jmerik V. N. , Mizerov A. M. , Kuznetsova Ya. V. , Zamoryanskaya M. V. , Ivanov S. V. , Toropov A. A. 
Published: February 2013

AbstractWe have performed micro‐photoluminescence (µ‐PL) mapping of InGaN films with thickness up to 300 nm with a large gradient of In concentration in a lateral direction (from 10% to 40%), grown by plasma‐assisted molecular beam epitaxy atop a 1.8‐µm‐thick GaN($000 \bar {\rm I}$) buffer deposited on a c‐Al2O3 substrate. The µ‐PL spectra measured at various points with different average composition show almost identical emission bands with fixed wavelength ranges: 490‐540 nm (green band), 550‐590 nm (orange band), and 600‐660 nm (red band). This behavior implies emergence of at least three phases with fixed In contents, which are nearly independent of the average film composition and the variation of the growth temperature. The variation of the average composition of the InGaN ternary alloy results in redistribution of the band intensities that can be explained by redistribution of the relative volumes of the spatially separated phases. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simultaneous determination of bisphenol A, aflatoxin B1, ochratoxin A, and patulin in food matrices by liquid chromatography/mass spectrometry
Authors: Song Wenlu , Li Charlie , Moezzi Bahman 
Published: February 2013

RATIONALEBisphenol A has been widely used in plastic containers and this has raised safety concerns for fetuses, infants, and young children. Aflatoxin B1, ochratoxin A, and patulin are among the most toxic regulated mycotoxins found as contaminants in agricultural crops and animal products. To facilitate the analysis of these chemicals for regulatory purposes, we have developed an analytical method enabling their simultaneous detection in beverages and food products.METHODSAnalytes were extracted from food matrices such as cereal, peanut butter, cereal‐based baby formula and fruit juices, and enriched by solid‐phase extraction (SPE). Samples were analyzed by liquid chromatography/mass spectrometry using negative electrospray ionization with selected reaction monitoring, and matrix‐matched external calibration was used for quantitation.RESULTSThe method was validated by analysis of five types of food and beverage samples fortified with different levels of these analytes. The SPE clean‐up and matrix‐matched external calibration were critical for the success of this method. The quantitation limits for these analytes ranged from 0.08 to 2.0 ppb, and the overall recoveries of the analytical method were within 66 to 127%.CONCLUSIONSThis quantitative method provided several advantages including minimal sample pretreatment, rapid and simultaneous analyte determination, high sensitivity and confirmatory identification. This method could be applied to a variety of food and beverages matrices where bisphenol A and these three mycotoxins may be present in suspect food products. Published 2013. This article is a US Government work and is in the public domain in the USA.
Biosensing Approaches for Rapid Genotoxicity and Cytotoxicity Assays upon Nanomaterial Exposure
Authors: Zhu Xuena , Hondroulis Evangelia , Liu Wenjun , Li Chen‐zhong 
Published: February 2013

AbstractThe increased utilization of nanomaterials could affect human health and the environment due to increased exposure. Several mechanisms regarding the negative effects of nanomaterials have been proposed, one of the most discussed being oxidative stress. Many studies have shown that some metal oxide nanoparticles can enhance reactive oxygen species generation, inducing oxidative stress, DNA damage, and unregulated cell signaling, and eventually leading to changes in cell motility, apoptosis, and even carcinogenesis. 8‐Hydroxy‐2′‐deoxyguanosine (8‐OHdG) is one of the predominant forms of oxidative DNA damage, and has therefore been widely used as a biomarker for oxidative stress and carcinogenesis. Ther are two major objectives to this study. Firstly, the development of a novel lateral flow immunoassay (LFIA) is presented to measure the concentration of 8‐OHdG in cells and thus reveal the nanotoxicity on the genomic level. The feasibility of this new method is validated by comparison with two other established methods: Alamar Blue assay and a recently developed electrical impedance sensing (EIS) system on the level of cell proliferation/viability. Secondly, the toxicological effects of three metallic nanoparticles (CuO, CdO, and TiO2) are investigated and compared using these three methods with completely different mechanisms. The results show that there is a high variation among different nanoparticles concerning their ability to cause toxic effects. CuO nanoparticles are the most potent regarding cytotoxicity and DNA damage. CdO shows a fallen cell viability as well as DNA damage, however, to a lesser extent than CuO nanoparticles. TiO2 particles only cause very limited cytotoxicity, and there is no obvious increase in 8‐OHdG levels. In conclusion, LFIA as well as the EIS system are useful methods for quantitative or qualitative nanotoxicity assessments with high sensitivity, specificity, speed of performance, and simplicity.
Thermodynamics for Precipitation of CaS Bearing Inclusion and Their Deformation During Rolling Process for Al‐Killed Ca‐Treated Steel
Authors: Guo Jing , Cheng Shusen , Cheng Zijian , Xin Lei 
Published: February 2013

AbstractThermodynamics for CaS bearing inclusions precipitation and their deformative behaviors during compact strip production (CSP) rolling process for Al‐killed calcium treatment steel were researched using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) combined with the results of industrial trials. In addition, thermodynamic software FactSage was applied to calculate component activities of an inclusion and to analyze properties of sulfide‐oxide duplex inclusions. It is possible for CaS bearing inclusion precipitation during secondary refining and continuous casting in two manners: the first is that Ca and S react directly after calcium treatment; the other is as the well modified calcium aluminates react with dissolved sulfur and aluminum in liquid steel. Correspondingly, two types of sulfide‐oxide duplex inclusion were observed in casting slab. For the first type duplex inclusion, nearly no chemical reactions occur between outer CaS layer and solid inclusion core, thus the outer CaS rich layer is easily separated even taken off from the inner core during rolling process, and a crack may be generated correspondingly. The later one performs a better deformation during rolling process.
Brief Report: Oct4 and Canonical Wnt Signaling Regulate the Cardiac Lineage Factor Mesp1 Through a Tcf/Lef-Oct4 Composite Element
Authors: Li Yongqing , Yu Wei , Cooney Austin J. , Schwartz Robert J. , Liu Yu 
Published: February 2013

Abstract
Oct4 is the gatekeeper of stem cell pluripotency, but recent evidences also support Oct4 as a key regulator of germ layer formation and lineage commitment. How Oct4 contributes to lineage commitment is not well understood. We identified a Tcf/Lef-Oct4 composite site in the promoter of the cardiac mesoderm gene Mesp1, with a nucleotide sequence identical to the previously established Sox2-Oct4 composite site. This Tcf/Lef-Oct4 composite site mediated synergistic activation of the Mesp1 promoter by Oct4 and canonical Wnt signaling. Transcription ternary complexes were formed with Oct4 and Wnt terminal components, Lef1. Point mutations on the Tcf/Lef-Oct4 composite site impaired Oct4 and Lef1 binding and Mesp1-β-gal transgene reporter expression during mouse embryogenesis. In ZHBTc4 murine embryonic stem cells, the loss of Oct4 during differentiation impaired Mesp1 expression and the development of the cardiac program. This Tcf/Lef-Oct4 composite site appears to be a unique nodal point regulatory element that may drive pluripotency via Sox2-Oct4 and switch on lineage-related genes through Oct4's recruitment of Tcf/Lef factors.
A Low‐Temperature Synthesis Route for CaAlSiN3 Doped with Eu2+
Authors: Kubus Mariusz , Meyer H.‐Jürgen 
Published: February 2013

AbstractA new low‐temperature synthesis route of the strongly red‐emitting Eu2+ activated nitride phosphor CaAlSiN3 is presented. The fluorides CaSiF6 and AlF3 were used as a source of metal ions and Li3N as a nitrogen source. A KCN/LiCl flux system was employed to lower the temperature of the reaction from 1100 to 750 °C. The course of the reaction was studied by differential thermal analysis, and the product of the reaction was inspected by X‐ray powder diffraction and luminescence measurements of CaAlSiN3:Eu.
Laparoscopic Rectopexy for Rectal Prolapse to Reduce Surgical‐Site Infections and Length of Stay
Authors: Magruder J. Trent , Efron Jonathan E. , Wick Elizabeth C. , Gearhart Susan L. 
Published: February 2013

AbstractBackgroundRectal prolapse is commonly seen in patients with significant co‐morbidities. Multiple approaches have been described, including the use of laparoscopy. The purpose of this study was to determine if laparoscopic approaches for repair of rectal prolapse are associated with less short‐term morbidity than open approaches.MethodsThe American College of Surgeons National Surgical Quality Improvement Program database was queried for patients who underwent laparoscopic or open rectopexy (R) or sigmoid resection and rectopexy (SR + R) between 2005 and 2008. Co‐morbidities analyzed included diabetes, body mass index, chronic obstructive pulmonary disease, hypertension, cardiac (history of congestive heart failure, myocardial infarction, peripheral vascular disease, previous percutaneous cardiac intervention or surgery), and neurologic disorder (history of transient ischemic attack or cerebrovascular accident). Postoperative complications analyzed included surgical‐site infections (SSIs), pneumonia, reintubation, pulmonary embolus, stroke, myocardial infarction, and sepsis. The χ2 or t test/ANOVA were used to assess significance for categoric and continuous variables, respectively. Logistic regression analysis was used to determine risk factors for morbidity after rectal prolapse repair.ResultsAltogether, 685 patients underwent surgical treatment of rectal prolapse. Most patients underwent open SR + R (open: 247 SR + R, 193 R; laparoscopic: 161 SR + R, 84 R). All patients had similar co‐morbidity profiles. Patients undergoing laparoscopic R were significantly older (mean age 61.4 years) than those in the other three groups (p = 0.04). Operating time ranged from 128 min (open R) to 185 min (laparoscopic SR + R; p < 0.001). Open SR + R and open R were associated with significantly more morbidity than laparoscopic SR + R and R [odds ratio (OR) 0.42, 95 % confidence interval (CI) 0.22–0.83, p = 0.01]. Comparing all four procedures, there was a trend to decreased overall morbidity with laparoscopic R, but without statistical significance (OR 0.31, 95 % CI 0.07–1.40, p = 0.13). Length of hospital stay (LOS) and SSI rates were significantly lower with laparoscopic R than with the other three procedures.ConclusionsPatients who undergo laparoscopic rectopexy have a shorter LOS and lower SSI rate than patients who undergo other abdominal procedures for repair of rectal prolapse. Further study is necessary to determine the long‐term outcomes from laparoscopic rectopexy, but in high‐risk patients the laparoscopic approach can decrease perioperative risk.
Clinical Fellowships in Surgical Training: Analysis of a National Pan‐specialty Workforce Survey
Authors: Fitzgerald J. E. F. , Milburn J. A. , Khera G. , Davies R. S. M. , Hornby S. T. , Giddings C. E. B. 
Published: February 2013

AbstractBackgroundFellowship posts are increasingly common and offer targeted opportunities for training and personal development. Despite international demand, there is little objective information quantifying this effect or the motivations behind undertaking such a post. The present study investigated surgical trainees’ fellowship aims and intentions.MethodsAn electronic, 38‐item, self‐administered questionnaire survey was distributed in the United Kingdom via national and regional surgical mailing lists and websites via the Association of Surgeons in Training, Royal Surgical Colleges, and Specialty Associations.ResultsIn all, 1,581 fully completed surveys were received, and 1,365 were included in the analysis. These represented trainees in core or higher training programs or research from all specialties and training regions: 66 % were male; the mean age was 32 years; 77.6 % intended to or had already completed a fellowship. Plastic surgery (95.2 %) and cardiothoracic (88.6 %) trainees were most likely to undertake a fellowship, with pediatrics (51.2 %), and urology (54.3 %) the least likely. Fellowship uptake increased with seniority (p < 0.01) and was positively correlated (p = 0.016, r = 0.767) with increasing belief that fellowships are necessary to the attainment of clinical competence, agreed by 73.1 %. Fellowship aims were ranked in descending order of importance as attaining competence, increasing confidence, and attaining subspecialist skills.ConclusionsOver three‐quarters of trainees have or will undertake a clinical fellowship, varying with gender, specialty, and seniority. Competence, confidence, and subspecialty skills development are the main aims. The findings will influence workforce planning, and perceptions that current training does not deliver sufficient levels of competence and confidence merit further investigation.
Descartes and the Bologna affair
Authors: MANNING GIDEON 
Published: February 2013

AbstractDescartes is well known as a mathematician and natural philosopher. However, none of Descartes's biographers has described the invitation he received in 1633 to fill a chair in theoretical medicine at the University of Bologna, or the fact that he was already sufficiently known and respected for his medical knowledge that the invitation came four years before his first publication. In this note I authenticate and contextualize this event, which I refer to as the ‘Bologna affair’. I transcribe the letter written to the Bolognese Senate announcing efforts to bring Descartes to the university and explain the events that led to Descartes receiving the invitation. While many questions about the Bologna affair cannot be answered because of the paucity of the historical record, I conclude that the event invites us to consider again the larger historiographical issue of how best to integrate the history of medicine with the history of science and philosophy during the early modern period.
Indices of fatty acid desaturase activity in healthy human subjects: effects of different types of dietary fat
Authors: Vessby Bengt , Gustafsson Inga-Britt , Tengblad Siv , Berglund Lars 
Published: February 2013

Δ9-Desaturase (stearoyl-CoA desaturase 1, SCD-1) regulates the desaturation of SFA, mainly stearic and palmitic, to MUFA. Δ6-Desaturase (D6D) and Δ5-desaturase (D5D) are involved in the metabolism of linoleic and α-linolenic acid to polyunsaturated metabolites. The objective of the present study was to study the effects of different types of dietary fat on indices of fatty acid desaturase (FADS) activity (evaluated as product:precursor ratios) in plasma and skeletal muscle in human subjects. A high SCD-1 index has been related to obesity and metabolic disorders, while the D5D index is associated with insulin sensitivity. Fatty acid composition of serum and skeletal muscle lipids was analysed by GLC during a randomised, controlled, 3-month dietary intervention in healthy subjects. A comparison of the effects of a diet containing butter fat (SFA,n17) with a diet containing monounsaturated fat (MUFA,n17), keeping all other dietary components constant, showed a reduced SCD-1 activity index by 20 % on the MUFA diet compared with the SFA diet assessed in serum cholesteryl esters. The D6D and D5D indices remained unaffected. Supplementation with long-chainn-3 fatty acids reduced the SCD-1 index by a similar magnitude while the D6D index decreased and the D5D index increased. It is concluded that changes in the type of fat in the diet affect the indices of FADS activity in serum and skeletal muscle in human subjects. The desaturase activity indices estimated from the serum lipid ester composition are significantly related to corresponding indices studied in skeletal muscle phospholipids.