bluuebunny/crossref_metadata_2025 huggingface dataset:
Durability Testing of a High‐Temperature Steam Electrolyzer Stack at 700 °C
Authors: Fu Q. , Schefold J. , Brisse A. , Nielsen J. U.
Published: February 2014

A 5‐cell solid oxide electrolyzer cell (SOEC) stack has been operated at ca. 700 °C for 2,000 h under static conditions followed by a short‐term transient operation. The best repeating unit (RU) showed an area specific resistance of 0.4 Ω cm2 and an initial voltage of 1.125 V at 705 °C and –0.6 A cm–2 when fed with 90% H2O/10% H2 at the hydrogen‐electrode. One instability factor has been observed, which led to dramatic voltage fluctuations for most RUs in the stack. Such kind of voltage fluctuation is correlated predominantly to the variation of ohmic resistances of RUs, pointing out most probably unstable electrical contact in the stack under the present testing conditions. Disregarding the worst RU (RU1), the average degradation rate (voltage increase rate) of all RUs in the stack has been determined to be around 2% kh–1 (24 mV kh–1) for the last 500 h of static operation free of voltage fluctuations. The stack showed no noticeable degradation during the short‐term transient operation (totally 756 ON/OFF current cycles), indicating preliminarily that it could be possible to couple intermittent power sources with high‐temperature steam electrolyzers.
Influence of Deposition Temperature of GDC Interlayer Deposited by RF Magnetron Sputtering on Anode‐Supported SOFC
Authors: Wu W. , Wang X. , Liu Z. , Zhao Z. , Ou D. , Tu B. , Cheng M.
Published: February 2014

Gadolinia‐doped ceria (GDC) film, as a barrier layer to prevent chemical reaction between yttria‐stabilized zirconia (YSZ) electrolyte and Ba0.5Sr0.5Co0.8Fe0.2O3–δ (BSCF)–GDC cathode, is deposited by radio frequency (RF) magnetron sputtering on YSZ electrolyte, and the influence of deposition temperature on Ni–YSZ/YSZ/GDC/BSCF–GDC single cell performance is investigated. The SEM results show that the GDC film deposited at 30 °C exhibits a porous structure, whereas the GDC film deposited at 400 °C has a dense structure. The single cells show excellent performance when the deposition temperature is above 250 °C, whereas the single cells show poor performance when the deposition temperature is below 200 °C. The large difference in cell performance occurs from their large difference in polarization resistance. The porous structure of GDC interlayer, which cannot well prevent the reaction between BSCF and YSZ, is responsible for the poor performance of the cells with GDC interlayer deposited at a temperature below 200 °C.
SOFC Cell Design Optimization Using the Finite Element Method Based CFD Approach
Authors: Andersson M. , Yuan J. , Sundén B.
Published: February 2014

Fuel cells are hopeful for future energy systems, because they are energy efficient and able to use renewable fuels. A coupled computational fluid dynamics approach based on the finite element method, in three‐dimensions, is used to illustrate a planar intermediate‐temperature solid oxide fuel cell. Governing equations for momentum, gas‐phase species, heat, electron and ion transport are implemented and coupled to kinetics describing electrochemical reactions. Three different cell designs are compared in a parametric study. The importance of the cathode support layer is revealed, because this layer significantly decreases the oxygen gas‐phase resistance within the cathode (at positions under the interconnect ribs) in the direction normal to the cathode/electrolyte interface as well as the electron resistance inside the cathode (at positions under the air channel) in the same direction. It is concluded that wider and thinner gas channels enable a more compact design with only a slightly decreased cell current density (per cross‐sectional electrode/electrolyte interface area), i.e. a considerably increased volumetric cell current can be achieved.
Networked Graphitic Structures as Durable Catalyst Support for PEM Electrodes
Authors: Negro E. , Vries M. A. De , Latsuzbaia R. , Koper G. J. M.
Published: February 2014

A PFSA‐stabilized Pt‐catalyst supported on a novel carbon material, carbon nano networks (CNNs), was synthesized. To benchmark its performance, it was compared to a commercial catalyst, supported on an amorphous carbon support, and to a PFSA stabilized Pt catalyst supported on commercial carbon nano tubes (CNTs). The PFSA‐Pt/CNNs exhibit improved performance compared to commercial catalysts in terms of ORR kinetic activity and durability. Even though PFSA‐Pt/CNTs should show comparable behavior to PFSA‐Pt/CNNs, our experimental results show a slightly superior performance. Optimization of the CNN synthesis route is expected to improve their properties as a carbon support. Since CNN mass production is expected to be cheaper than for CNTs because of the simplicity of the synthesis route, we conclude that CNNs are a promising material for the fuel cell market.
An interaction platform for mechanized tunnelling. Application on the Wehrhahn‐Line in Düsseldorf (Germany) / Eine Interaktionsplattform für maschinelle Tunnelvortriebe. Anwendung am Beispiel der Wehrhahn‐Linie in Düsseldorf
Authors: Schindler Steffen , Hegemann Felix , Alsahly Abdullah , Barciaga Thomas , Galli Mario , Lehner Karlheinz , Koch Christian
Published: February 2014

This paper introduces a holistic product model for the interactive simulation of shield tunnelling machines. The underlying product model is based on the Building Information Modelling methodology and uses the Industry Foundation Classes to classify and structure the captured data. Data from design, measurements and numerical simulation components obtained from four sub‐models (ground, tunnel, tunnel boring machine and building) are stored, classified and organized on commonly available servers. The very heterogeneous data structures found in each individual model are adjusted in advance using georeferencing, transformation or other suitable methods to increase compatibility. In particular, this article describes the methodological design of an interactive product model for mechanized tunnelling in soft soil, including its sub‐models. Performance is demonstrated by a case study using data from the Wehrhahn‐Line subway construction site in Düsseldorf, Germany. Here, the focus is on the verification of the product model and its use in the numerical simulations. The research presented is a central component of the Collaborative Research Center SFB 837 “Interaction Modelling in Mechanized Tunnelling” at the Ruhr University, Bochum.

Zur interaktiven Simulation von maschinellen Schildvortrieben wird ein ganzheitliches Produktmodell vorgestellt. Das Produktmodell basiert auf der Methode des Building Information Modelings und nutzt zur Strukturierung der Daten das Datenaustauschformat Industry Foundation Classes (IFC). Zentral gespeicherte Daten aus Planung, Messungen oder numerischen Simulationen von insgesamt vier Untermodellen (Baugrund, Tunnel, Tunnelvortriebsmaschine und Bebauung) werden klassifiziert und wiederum zur weiteren Nutzung organisiert. Die sehr heterogene Datenstruktur der einzelnen Untermodelle wird im Vorfeld durch Georeferenzierung, Transformation und andere geeignete Verfahren angepasst. Der Beitrag beschreibt den methodischen Aufbau des interaktiven Produktmodells für den Tunnelvortrieb im Lockergestein einschließlich seiner Untermodelle. Die Leistungsfähigkeit zeigt ein Fallbeispiel mit Daten der U‐Bahnbaustelle Wehrhahn‐Linie in Düsseldorf. Hierbei liegt der Schwerpunkt auf der Verifizierung des Produktmodells sowie auf verknüpften Simulationen und übergreifenden Analysen. Die Forschungsarbeiten sind zentraler Bestandteil des Sonderforschungsbereichs SFB 837 “Interaktionsmodelle für den maschinellen Tunnelbau” an der Ruhr‐Universität Bochum.
A Simple Synthesis of Polyfunctionalized 4‐Aminopyrazolidin‐3‐ones as ‘Aza‐deoxa’ Analogs of D‐Cycloserine
Authors: Novak Ana , Štefanič Matej , Grošelj Uroš , Hrast Martina , Kasunič Marta , Gobec Stanislav , Stanovnik Branko , Svete Jurij
Published: February 2014

A simple five‐step synthesis of fully substituted (4RS,5RS)‐4‐aminopyrazolidin‐3‐ones as analogs of D‐cycloserine was developed. It comprises a two‐step preparation of 5‐substituted (4RS,5RS)‐4‐(benzyloxycarbonylamino)pyrazolidin‐3‐ones, reductive alkylation at N(1), alkylation of the amidic N(2) with alkyl halides, and simultaneous hydrogenolytic deprotection/reductive alkylation of the primary NH2 group. The synthesis enables an easy stepwise functionalization of the pyrazolidin‐3‐one core with only two types of common reagents, aldehydes (or ketones) and alkyl halides. The structures of products were elucidated by NMR spectroscopy and X‐ray diffraction.
Purification of Enantiomeric Mixtures in Enantioselective Synthesis: Overlooked Errors and Scientific Basis of Separation in Achiral Environment
Authors: Martens Jürgen , Bhushan Ravi
Published: February 2014

The syntheses of optically active compounds (whether of pharmaceutical or synthetic importance, or as promising candidates as chiral ligands and auxiliaries in asymmetric syntheses) result in the formation of a mixture of products with one enantiomer predominating. Usually, the practice is to use standard open‐column chromatography for the first purification step in an enantioselective synthesis; the workup of the reaction product by crystallization or achiral chromatography would mask the real efficiency of the enantioselective methodology, since enantiomeric ratio (er) of the product may change by any of these methods. Most of the synthetic organic chemists are aware of the influence of crystallization on the er value.

Majority of synthetic organic chemists are, however, not aware, while employing standard chromatography, that there may be an increase or decrease of er value. In other words, an undesired change in er goes unnoticed when such a mixture of enantiomers is isolated by chromatography on an achiral‐phase because of the prevalent concept of basic stereochemistry. Such unnoticed errors in enantioselective reactions may lead to misinterpretations of the enantioselective outcome of the synthesis. The scientific issue is, what is the difference between a racemic and nonracemic mixture in achiral environment (e.g., achiral‐phase chromatography) that leads to enantiomeric enrichment, amounting to separation of one particular enantiomer?

There are sporadic reports on enantiomer separation of nonracemic mixtures in an achiral environment particularly from the scientists working in analytical chemistry. To cover/discuss all these reports is out of the scope of this article.

The aim of the present report is to draw attention to the following points: i) How should the synthetic organic chemists and analytical chemists take care of the unexpected separation of enantiomers from nonracemic mixtures in a totally achiral environment? ii) What are the technical terms used in recent literature? iii) The requirement of revisiting definitions/terms (introduced in recent years, in particular) to describe such separations of enantiomers in light of prevalent scientific/chemical terminology used in the ‘language of chemistry’, the text book concept, and IUPAC background. iv) To propose logical scientific terminology or phrases for explaining the possible mechanism of separation under these conditions. v) To discuss briefly the concept/possibile phenomenon responsible for these enantioselective effects. It is also attempted to explain the effect of change of physical parameters influencing the separation from nonracemic mixture in achiral‐phase chromatography.
Targeted ex vivo reduction of CD64‐positive monocytes in chronic myelomonocytic leukemia and acute myelomonocytic leukemia using human granzyme B‐based cytolytic fusion proteins
Authors: Schiffer Sonja , Rosinke Reinhard , Jost Edgar , Hehmann‐Titt Grit , Huhn Michael , Melmer Georg , Barth Stefan , Thepen Theo
Published: February 2014

CMML (chronic myelomonocytic leukemia) belongs to the group of myeloid neoplasms known as myelodysplastic and myeloproliferative diseases. In some patients with a history of CMML, the disease transforms to acute myelomonocytic leukemia (AMML). There are no specific treatment options for patients suffering from CMML except for supportive care and DNA methyltransferase inhibitors in patients with advanced disease. New treatment strategies are urgently required, so we have investigated the use of immunotherapeutic directed cytolytic fusion proteins (CFPs), which are chimeric proteins comprising a selective domain and a toxic component (preferably of human origin to avoid immunogenicity). The human serine protease granzyme B is a prominent candidate for tumor immunotherapy because it is expressed in cytotoxic T lymphocytes and natural killer cells. Here, we report the use of CD64 as a novel target for specific CMML and AMML therapy, and correlate CD64 expression with typical surface markers representing these diseases. We demonstrate that CD64‐specific human CFPs kill CMML and AMML cells ex vivo, and that the mutant granzyme B protein R201K is more cytotoxic than the wild‐type enzyme in the presence of the granzyme B inhibitor PI9. Besides, the human CFP based on the granzyme B mutant was also able to kill AMML or CMML probes resistant to Pseudomonas exotoxin A.
Prognostic value of phospho‐Akt in patients with non‐small cell lung carcinoma: A meta‐analysis
Authors: Yang Yang , Luo Jialin , Zhai Xiaoming , Fu Zhiqin , Tang Zhongzhu , Liu Luying , Chen Ming , Zhu Yuan
Published: February 2014

Previous studies have been inconsistent with respect to the reported associations between phospho‐Akt (p‐Akt) overexpression and lung cancer prognosis. In this study, we conducted a systematic review and meta‐analysis to assess the prognostic value of p‐Akt in patients with non‐small cell lung carcinoma (NSCLC). Relevant articles were identified by searching MEDLINE. Hazard risks (HRs) from individual studies were calculated and pooled by using a random‐effect model, and heterogeneity and publication bias analyses were also performed. Finally, 18 studies comprising 2,353 patients were included in the meta‐analysis. p‐Akt overexpression was associated with worse survival in NSCLC patients, and the pooled HRs for all the studies was 1.38 (95% confidence interval [CI]: 1.11–1.70; p < 0.01). After subgroup analysis, the association was strengthened in the surgery treatment group, with an HR of 1.44 (95% CI: 1.19–1.75; p < 0.01), while in the tyrosine kinase inhibitors treatment group, the statistical significance disappeared (HR: 1.22, 95% CI: 0.70–2.14; p = 0.48). The HR in cases of early stage disease (I–III) was 1.35 (95% CI: 1.08–1.69; p = 0.04); however, in cases of late stage disease (III–IV), the association became non‐significant (HR: 1.22, 95% CI: 0.64–2.33; p = 0.54). Our results suggest that there was a significantly inverse association between p‐Akt overexpression and the prognosis of NSCLC patients, and that this association appeared to be limited in early‐stage patients who underwent surgery.
Tablet computers for hospitalized patients: A pilot study to improve inpatient engagement
Authors: Greysen S. Ryan , Khanna Raman R. , Jacolbia Ronald , Lee Herman M. , Auerbach Andrew D.
Published: February 2014

Inadequate patient engagement in hospital care inhibits high‐quality care and successful transitions to home. Tablet computers may provide opportunities to engage patients, particularly during inactive times between provider visits, tests, and treatments, by providing interactive health education modules as well as access to their personal health record (PHR). We conducted a pilot project to explore inpatient satisfaction with bedside tablets and barriers to usability. Additionally, we evaluated use of these devices to deliver 2 specific Web‐based programs: (1) an interactive video to improve inpatient education about hospital safety, and (2) PHR access to promote inpatient engagement in discharge planning. We enrolled 30 patients; 17 (60%) were aged 40 years or older, 17 (60%) were women, 17 (60%) owned smartphones, and 6 (22%) owned tablet computers. Twenty‐seven (90%) reported high overall satisfaction with the device, and 26 (87%) required ≤30 minutes for basic orientation (70% required ≤15minutes). Twenty‐five (83%) independently completed an interactive educational module on hospital patient safety. Twenty‐one (70%) accessed their personal health record (PHR) to view their medication list, verify scheduled appointments, or send a message to their primary care physician. Next steps include education on high‐risk medications, assessment of discharge barriers, and training clinical staff (such as respiratory therapists, registered nurses, or nurse practitioners) to deliver tablet interventions. Journal of Hospital Medicine 2014;9:396–399. © 2014 Society of Hospital Medicine
New bone formation enhanced by ADSCs overexpressing hRunx2 during mandibular distraction osteogenesis in osteoporotic rabbits
Authors: Sun Jing‐Jing , Zheng Xiao‐Hui , Wang Li‐Ya , Liu Lei , Jing Wei , Lin Yun‐Feng , Tian Weidong , Tang Wei , Long Jie
Published: February 2014

Promoting new bone formation during distraction osteogenesis (DO) in elderly patients with osteoporosis is still a challenge. In this study, we investigated the effect of gene therapy using local Runt‐related gene 2 on new bone formation during osteoporotic mandibular DO in rabbits. First, we successfully established a mandibular osteoporotic animal model by ovariectomizing rabbits. Second, the right mandibles of the osteoporotic rabbits were distracted after corticotomy. The distraction gap of the rabbits in Group A2 and B2 were injected with Adv‐hRunx2‐GFP‐transfected adipose‐derived stromal cells (ADSCs) and Adv‐GFP‐transfected ADSCs, respectively. Rabbits in Groups C2 (ovariectomized control) and D2 (sham surgery control) were injected with physiologic saline. New‐generation bone tissue in the distraction gap was analyzed via plain radiographic examinations, micro‐computed tomography, histological examinations, and biomechanical testing at weeks 3, 6, and 9 of the consolidation period. Results of above examinations showed that no ideal new bone formation was observed in Groups B2 and C2, but obvious ideal new bone formation was observed in Group A2 and D2. The results suggested that gene therapy using rhRunx2‐modified ADSCs promoted new bone formation during osteoporotic mandibular DO and effectively compensated for the detrimental effects of systemic osteoporosis on new bone formation. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:709–720, 2014.
Three‐dimensional motion analysis of the patellar component in total knee arthroplasty by the image matching method using image correlations
Authors: Ishimaru Masami , Shiraishi Yoshitaka , Ikebe Satoru , Higaki Hidehiko , Hino Kazunori , Onishi Yoshio , Miura Hiromasa
Published: February 2014

In total knee arthroplasty (TKA), the patella is significantly associated with range of motion and gait performance. Currently, no highly accurate methods are available that can measure the 3D in vivo behavior of the TKA patellar component, as the component is made of x‐ray‐permeable ultra‐high molecular weight polyethylene. Previously, we developed a computer simulation that matches CT scan and unidirectional radiographic images using image correlations, and applied it to kinematic studies of natural and TKA knees. The examination of the measurement accuracy for the patellar bone of a fresh‐frozen pig knee joint yielded a root mean square error of 0.2 mm in translation and 0.2° in rotation. In this study, we recruited four patients who had a TKA and investigated 3D movements of the patellar component during squatting. We could visualize the patellar component using the position of the holes drilled for the component peg, and estimated and visualized the contact points between the patellar and femoral components. The principles and the utility of the simulation method are reported. This analytical method is useful for evaluating the pathologies and post‐surgical conditions of the knee and other joints. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:619–626, 2014.
The First Photochemical In Situ Production of Ti‐Based Nanoparticles: A SH2 Strategy Using Bis(cyclopentadienyl)titanium Dichloride (Cp2TiCl2)
Authors: Versace Davy‐Louis , Fouassier Jean‐Pierre , Lalevée Jacques
Published: February 2014

Bis(cyclopentadienyl)titanium dichloride (Cp2TiCl2) is a high performance additive under UV light activation for both i) radical photopolymerization reactions (when added to a Type I photo­initiator such as 2,2‐dimethoxy‐2‐phenylacetophenone, the oxygen inhibition is reduced) and ii) a concomitant in situ photoinduced and oxygen mediated formation of Ti‐based nanoparticles (diameters ranging from 45 to 220 nm). The photochemical properties of Cp2TiCl2 are investigated by steady state photolysis and electron spin resonance, and its photoinitiation ability checked. The nanoparticles (NPs) are well characterized by transmission electron microscopy. The high reactivity of Cp2TiCl2 under air is ascribed to a bimolecular homolytic substitution (the SH2 process is clearly demonstrated by density functional theory calculations and ESR experiments), which converts the peroxyls into new efficient initiating radicals. The photochemical in situ incorporation of Ti NPs has never previously been reported. The synthesis of metal nanoparticles by a SH2 approach instead of the reduction of a metal salt appears to be a promising original method.

image
Shielding Effects in Polymer‐Polymer Reactions, 6
Authors: Eisenhaber Stephan , Zifferer Gerhard
Published: February 2014

Pairs of linear chains – the end segment of one of each fixed at a surface – are analyzed for the relative probability of mutual contact formation between particularly specified segments i and j belonging to different chains within these pairs. Several positions are of general interest only, while other portray specific experimental conditions, e.g., the basic step in surface initiated Z‐RAFT polymerization (contact of the end of the free chain with the anchored segment of the fixed one). Contact probabilities are calculated for athermal cubic lattice chains by means of exact enumeration. Basic results are chain‐length dependences of shielding factors Kij in form of scaling laws and changes of size and shape properties of the involved molecules while approaching and penetration as functions of chain separation.
Weak Galerkin finite element methods for the biharmonic equation on polytopal meshes
Authors: Mu Lin , Wang Junping , Ye Xiu
Published: February 2014

A new weak Galerkin (WG) finite element method is introduced and analyzed in this article for the biharmonic equation in its primary form. This method is highly robust and flexible in the element construction by using discontinuous piecewise polynomials on general finite element partitions consisting of polygons or polyhedra of arbitrary shape. The resulting WG finite element formulation is symmetric, positive definite, and parameter‐free. Optimal order error estimates in a discrete H2 norm is established for the corresponding WG finite element solutions. Error estimates in the usual L2 norm are also derived, yielding a suboptimal order of convergence for the lowest order element and an optimal order of convergence for all high order of elements. Numerical results are presented to confirm the theory of convergence under suitable regularity assumptions. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1003–1029, 2014
Synthesis, characterization, and electroluminescence of fluorene and carbazole‐based blue light‐emitting polymers with different noncoplanar molecular architectures
Authors: Jiang Hong‐Ji , Zhang Jin‐long
Published: February 2014

In order to investigate the explicit optoelectronic variations of the photoluminescent polymer with sterically hindered side chains, three novel alternate polymers (P0, P1, and P2) based on fluorene and carbazole moieties were successfully synthesized through Suzuki coupling reaction. The molecular structures of the polymers were fully characterized by 1H‐NMR, 13C‐NMR, elemental analysis, and gel permeation chromatograph, respectively. The photophysical properties, thermal stability, and energy band gaps of polymers P0, P1, and P2 were further examined through UV–vis absorption, photoluminescent spectra, differential scanning calorimetry, thermogravimetric analysis, and cyclic voltammetry. The experimental results indicated that the polymers took on wide band gaps of about 3.50 eV with deep blue emission in thin solid films. These polymers were found to show a high thermal stability with decomposition temperatures at 5% weight loss of the compounds in the range of 353–416 °C. Blue light‐emitting electroluminescent devices of the most branched polymer P2 with highest light‐emitting efficiency as emitting layers were characterized, which showed obviously improved spectral stabilities with respect to the parent polyfluorene materials. In conclusion, we have established an effective method to improve the spectral stabilities of polyfluorene material by synthesizing the zigzag‐shaped copolymer of fluorene and carbazole with sterically hindered pendant moieties of different molecular sizes. Copyright © 2014 John Wiley & Sons, Ltd.
Patterns of failure after involved field radiation therapy for pediatric and young adult Hodgkin lymphoma
Authors: Huynh‐Le Minh‐Phuong , Walker Amanda J. , Kominers Scott Duke , Paz‐Priel Ido , Wharam Moody D. , Terezakis Stephanie A.
Published: February 2014

Background

Involved field radiation therapy (IFRT) is integral in curative therapy for Hodgkin lymphoma (HL), although primarily used in patients with intermediate/high‐risk HL. We present failure patterns and clinical outcomes in a cohort of pediatric and young adult patients with HL treated with IFRT at the Johns Hopkins Hospital.

Procedure

Patients ≤40 years old with intermediate/high‐risk HL who received chemotherapy and IFRT from 1997 to 2012 were included in this retrospective analysis. Patients were evaluated for failure patterns, overall survival (OS), and event‐free survival (EFS) using Kaplan–Meier curves, descriptive statistics, and Cox proportional hazard regressions.

Results

We reviewed 74 patients (45 pediatric and 29 young adult) with a median follow‐up of 4.4 years. The mean age at diagnosis was 21.4 years. Patients received a median of 29.75 Gy of IFRT (range 15–39.6 Gy). The majority of pediatric patients received ABVE‐PC chemotherapy (n = 25) and <30 Gy of radiation (n = 33) while most young adults received ABVD chemotherapy (n = 24) and ≥30 Gy (n = 25). Estimated 5‐year OS and EFS were 96% and 81%, respectively. Thirteen patients had recurrence; eight were pediatric. Distant relapse alone comprised 83% of failures in patients receiving ≥30 Gy. Of the seven patients who received <30 Gy and had recurrence, six had local failure as a component of their recurrence. Caucasian race (P = 0.02) and nodular sclerosing histology (P = 0.01) predicted for increased EFS. Late effects were minimal and all deaths (n = 4) were from HL.

Conclusions

In this series, pediatric and young adult patients were treated with differing chemoradiation and had distinct recurrence patterns. Pediatr Blood Cancer 2014;61:1210–1214. © 2014 Wiley Periodicals, Inc.
Synthetic adhesive attachment discs inspired by spider's pyriform silk architecture
Authors: Jain Dharamdeep , Sahni Vasav , Dhinojwala Ali
Published: February 2014

Spiders attach their major ampullate silk dragline fibers to surfaces using attachment discs spun from pyriform silk fibers. These attachment discs allow spiders to move safely from place to place while secured to a dragline and to attach their webs to a variety of surfaces. Here, we demonstrate a simple electrospinning process to mimic the “staple‐pin” architecture used by spiders for these attachment discs. Experimental and theoretical evidence are provided to confirm the advantages of thousands of micron‐size “staple‐pins” and their low peeling angles to enhance the adhesive forces required to peel the natural and synthetic attachment discs. These results provide a unique architectural design for fabricating new adhesives that uses very little material for various biomedical and material science applications. © 2014 Wiley Periodicals, Inc. J Polym Sci Part B: Polym. Phys. 2014, 52, 553–560
Laser desorption time‐of‐flight mass spectrometry of atomic switch memory Ge2Sb2Te5 bulk materials and its thin films
Authors: Houška Jan , Peña‐Méndez Eladia Maria , Kolář Jakub , Přikryl Jan , Pavlišta Martin , Frumar Miloslav , Wágner Tomáš , Havel Josef
Published: February 2014

RATIONALE

Although the structure of atomic switch Ge2Sb2Te5 (GST) thin films is well established, the composition of the clusters formed in the plasma plume during pulsed‐laser deposition (PLD) is not known. Laser Desorption Ionization Time‐of‐Flight Mass Spectrometry (LDI‐TOF MS) is an effective method for the generation and study of clusters formed by laser ablation of various solids and thus for determining their structural fragments.

METHODS

LDI of bulk or PLD‐deposited GST thin layers and of various precursors (Ge, Sb, Te, and Ge‐Te or Sb‐Te mixtures) using a nitrogen laser (337 nm) was applied while the mass spectra were recorded in positive and negative ion modes using a TOF mass spectrometer equipped with a reflectron while the stoichiometry of the clusters formed was determined via isotopic envelope analysis.

RESULTS

The singly negatively or positively charged clusters identified from the LDI of GST were Ge, Ge2, GeTe, Ge2Te, Ten (n = 1–3), GeTe2, Ge2Te2, GeTe3, SbTe2, Sb2Te, GeSbTe2, Sb3Te and the low abundance ternary GeSbTe3, while the LDI of germanium telluride yielded GemTen+ clusters (m = 1–3, n = 1–3). Several minor Ge‐H clusters were also observed for pure germanium and for germanium telluride. Sbn clusters (n = 1–3) and the formation of binary TeSb, TeSb2 and TeSb3 clusters were detected when Sb2Te3 was examined.

CONCLUSIONS

This is the first report that elucidates the stoichiometry of GemSbnTep clusters formed in plasma when bulk or nano‐layers of GST material are ablated. The clusters were found to be fragments of the original structure. The results might facilitate the development of PLD technology for this memory phase‐change material. Copyright © 2014 John Wiley & Sons, Ltd.
A rapid and high‐precision method for sulfur isotope δ34S determination with a multiple‐collector inductively coupled plasma mass spectrometer: matrix effect correction and applications for water samples without chemical purification
Authors: Lin An‐Jun , Yang Tao , Jiang Shao‐Yong
Published: February 2014

RATIONALE

Previous studies have indicated that prior chemical purification of samples, although complex and time‐consuming, is essential in obtaining precise and accurate results for sulfur isotope ratios using multiple‐collector inductively coupled plasma mass spectrometry (MC‐ICP‐MS). In this study, we introduce a new, rapid and precise MC‐ICP‐MS method for sulfur isotope determination from water samples without chemical purification.

METHODS

The analytical work was performed on an MC‐ICP‐MS instrument with medium mass resolution (m/Δm ~ 3000). Standard‐sample bracketing (SSB) was used to correct samples throughout the analytical sessions. Reference materials included an Alfa‐S (ammonium sulfate) standard solution, ammonium sulfate provided by the lab of the authors and fresh seawater from the South China Sea. A range of matrix‐matched Alfa‐S standard solutions and ammonium sulfate solutions was used to investigate the matrix (salinity) effect (matrix was added in the form of NaCl). A seawater sample was used to confirm the reliability of the method.

RESULTS

Using matrix‐matched (salinity‐matched) Alfa‐S as the working standard, the measured δ34S value of AS (−6.73 ± 0.09‰) was consistent with the reference value (−6.78 ± 0.07‰) within the uncertainty, suggesting that this method could be recommended for the measurement of water samples without prior chemical purification. The δ34S value determination for the unpurified seawater also yielded excellent results (21.03 ± 0.18‰) that are consistent with the reference value (20.99‰), thus confirming the feasibility of the technique.

CONCLUSIONS

The data and the results indicate that it is feasible to use MC‐ICP‐MS and matrix‐matched working standards to measure the sulfur isotopic compositions of water samples directly without chemical purification. In comparison with the existing MC‐ICP‐MS techniques, the new method is better for directly measuring δ34S values in water samples with complex matrices; therefore, it can significantly accelerate analytical turnover. Copyright © 2014 John Wiley & Sons, Ltd.
Influence of Texture on Welding Stress Calculations
Authors: Decroos Koen , Ohms Carsten , Petrov Roumen , Seefeldt Marc , Verhaeghe Frederik , Kestens Leo
Published: February 2014

Upon solidification of the fusion zone of an austenitic weld the grains have a preferential <100> orientation aligning with the macroscopic solidification direction. The bulk material properties are consequently locally transversally isotropic with the solidification direction as fiber axis. A method is described to calculate the elastic and plastic anisotropy of the fusion zone bulk material and to implement the transversal isotropic material in Finite Element models for welding stress calculations. Results show a difference in predicted stress in the vicinity of the fusion zone when compared with a model with isotropic material properties.
Microwave‐Assisted Nonaqueous Synthesis of Doped Ceria Nanoparticles Assembled into Flakes
Authors: Hilaire Sandra , Luo Li , Rechberger Felix , Krumeich Frank , Niederberger Markus
Published: February 2014

Undoped and doped CeO2nanoparticles were synthesized through a combination of microwave‐assisted nonaqueous sol‐gel route and thermal treatment at 300 °C. Nanocrystals of 3 nm were obtained and characterized in detail by Rietveld refinement analysis of the X‐ray diffraction data and by electron microscopy. The refinement indicated that the doping with 3d transition metals (Co, Cu, Fe, and Ni) was successfully achieved and this result was additionally confirmed by EDX measurements. Investigation of the particle morphology by electron microscopy revealed that the nanocrystals were generally not present as primary particles, but self‐assembled into often intergrown flakes with uniform diameters of about 150 nm. In selected cases, the ceria nanocrystals are crystallographically oriented with respect to each other within one flake. BET measurements revealed a high surface area of 126 m2·g–1.
Effects of management strategies on glucocorticoids and behavior in Indian rhinoceros (Rhinoceros unicornis): Translocation and operant conditioning
Authors: Capiro Jonnie M. , Stoops Monica A. , Freeman Elizabeth W. , Clawson Dave , Schook Mandi W.
Published: February 2014

The ex situ Indian rhino population experienced a decrease in genetic diversity indicating that the breeding program could possibly benefit from novel reproductive management strategies to ensure population sustainability. We sought to determine how management tools used for reproductive management, specifically translocation and operant conditioning, impact physiological and behavioral measures of welfare in Indian rhinos. First, an adrenocorticotropic hormone challenge performed in an adult male resulted in a 38‐fold increase in urinary and a 3.5‐fold increase in fecal glucocorticoid metabolites (FGM). Mean and peak FGM differed among three females, but all demonstrated elevated (P < 0.0001) concentrations for variable durations after translocation that lasted up to 9 weeks. Lastly, behavioral and adrenal responses of two females to operant conditioning to stand during transrectal ultrasound exams were monitored and rhinos differed in their mean and peak FGM concentrations. However, FGM were not different before versus during training or on pasture versus in the barn. One female exhibited more stereotypic behavior during training in the barn than on pasture (P < 0.05); although, stereotypies (1.73% of time) were relatively uncommon overall. In summary, individual variation exists in FGM both at baseline levels and in response to a stressor. In addition, while a transient rise in glucocorticoid activity post‐translocation indicated that Indian rhinos have a physiological response to changes in their environment, minor alterations in daily routines using operant conditioning only resulted in minimal changes in behaviors and FGM. Zoo Biol. 33:131–143, 2014. © 2014 Wiley Periodicals Inc.
Comparison of Fatty Acid Profile of Specialty Maize to Normal Maize
Authors: Sanjeev P. , Chaudhary D. P. , Sreevastava P. , Saha S. , Rajenderan A. , Sekhar J. C. , Chikkappa G. K.
Published: February 2014

Increasing utilization of specialty maize prompted us to evaluate its fatty acid profile. For this purpose maize germplasm, classified as low oil normal maize (group 1), high oil normal maize (group 2), quality protein maize (QPM) (group 3) and sweet corn (group 4) was evaluated for oil, starch, protein and fatty acid composition mainly palmitic, stearic, oleic and linoleic acid. High oil content was observed in sweet corn samples which might be result of shriveled grain texture because of an increased embryo to kernel ratio. Individual fatty acids showed wide differences among different groups. A slightly higher amount of palmitic acid was reported in specialty maize as compared to normal maize. In contrast, stearic acid content was significantly low in high oil normal maize (56 %), QPM (36.2 %) and sweet corn (28.4 %) in comparison to low oil normal maize. Although no significant differences were observed for oleic acid between low oil normal and high oil normal maize, but sweet corn samples showed significantly reduced oleic acid compared to low oil normal maize. However, the most important observation was the higher content of linoleic acid in specialty maize (groups 2, 3 and 4) as compared to low oil normal maize. Further, the ratio of MUFA/PUFA was also discussed. It was concluded that specialty maize possesses a better oil quality in comparison to low oil normal maize.
Effect of single‐oocyte culture system on in vitro maturation and developmental competence in mice
Authors: Nishio Manami , Hoshino Yumi , Tanemura Kentaro , Sato Eimei
Published: February 2014

Purpose

To investigate whether single‐culture systems influence the quality of in vitro‐matured oocytes, we examined the maturation and developmental competence of oocytes obtained by grouped in vitro maturation (IVM) or single IVM.

Methods

In vitro‐matured oocytes were obtained using the culture drop (CD) method for the grouped IVM experiments, and the CD and hanging drop (HD) method for the single IVM experiments. To evaluate oocyte developmental competence, we performed in vitro fertilization and culture, and counted the number of blastocysts. To evaluate the oocyte cytoplasmic maturation, we measured the maturation promoting factor (MPF) expression levels.

Results

Oocytes cultured singly had lower maturity and developmental competence than the grouped IVM oocytes. However, enhanced oocyte fertility and blastocyst quality was achieved by the HD single IVM method. Additionally, the MPF activity level increased in all culture methods, compared to the control; however, it lagged behind nuclear maturation.

Conclusions

These results suggest that the HD method is efficient for single IVM.
Low pH‐induced regulation of excitation energy between the two photosystems
Authors: Jajoo Anjana , Mekala Nageswara Rao , Tongra Teena , Tiwari Arjun , Grieco Michele , Tikkanen Mikko , Aro Eva-Mari
Published: February 2014

Earlier studies have proposed that low pH causes state transitions in spinach thylakoid membranes. Several Arabidopsis mutants (stn7 incapable in phosphorylation of LHC II, stn8 incapable in phosphorylation of PSII core proteins, stn7 stn8 double mutant and npq4 lacking PsbS and hence qE) were used to investigate the mechanisms involved in low pH induced changes in the thylakoid membrane. We propose that protonation of PsbS at low pH is involved in enhancing energy spillover to PS I.
Prenatal diagnostic testing among women referred for advanced maternal age in Beijing, 2001–2012
Authors: Ma Jingmei , Hong Pan , Fu Jie , Yu Li , Yang Huixia
Published: February 2014

Objective

To determine the proportion of women with advanced maternal age (AMA) undergoing amniocentesis and assess the recommended indication of 35 years or older in China.

Methods

Data were retrospectively evaluated from 9641 patients who underwent diagnostic prenatal amniocentesis in Beijing, China, between January 2001 and December 2012. Maternal age, indication for testing, and karyotype data were collected. Patients referred for AMA were stratified in 2 ways: 35–37 years, 38–40 years, and 41 years or older; and indication of AMA alone or combined with other screening. Outcomes and safety performance were compared among the groups.

Results

From 2001 to 2012, the annual rate of amniocentesis and the proportion of AMA‐related indications increased (P< 0.01). Overall, 82 abnormalities were detected. In the AMA group, the spontaneous abortion rate was 0.5% (22/4748). The positive predictive value (PPV) of AMA alone was 0.5% for women aged 35–37 years. Only among women aged 41 years or older was the PPV of AMA alone better than that of AMA plus other indications (2.3% vs 1.5%, respectively).

Conclusion

The PPV of 35 years or older did not offset the risk of spontaneous abortion. AMA alone should not be used as an indication for amniocentesis especially among women aged 35–40 years.
Wave turbulence in a rotating channel
Authors: Scott Julian F.
Published: February 2014

This paper describes wave-turbulence closure and its consequences for rapidly rotating (i.e. small Rossby number) turbulence confined by two infinite, parallel walls perpendicular to the rotation axis. Expressing the flow as a combination of inertial waveguide modes leads to a spectral matrix, whose diagonal elements express the distribution of energy over modes and whose off-diagonal elements represent correlations between modes of different orders. In preparation for wave-turbulence closure, the flow is decomposed into two-dimensional and wave components. The former is found to evolve as if it were a classical, two-dimensional, non-rotating flow, but with wall friction due to Ekman pumping by the boundary layers. Evolution equations for the wave-component elements of the spectral matrix are derived using a wave-turbulence approach. Detailed analysis of these equations shows that, surprisingly, the two-dimensional component has no effect on wave-component energetics. As expected for wave turbulence, energy transfer between wave modes is via resonant triads and takes place at times $O(\varepsilon ^{-2})$ multiples of the rotational period, where $\varepsilon $ is the Rossby number. Despite playing no role in wave-mode energetics, the two-dimensional component produces decay of the off-diagonal elements of the spectral matrix on a time scale that is small compared with $O(\varepsilon ^{-2})$ rotation periods. There are thus three asymptotically distinct stages in the evolution of the turbulence in the limit of small Rossby number: the two-dimensional flow begins to evolve at the usual large-eddy turnover time scale ($O(\varepsilon ^{-1})$ multiples of the rotation period) and continues to develop thereafter. This is followed by decorrelation of different wave orders and finally evolution of the wave energy spectra due to resonant interactions.
Herder, Postcolonial Theory and the Antinomy of Universal Reason
Authors: Noyes John K.
Published: February 2014

The writings of Johann Gottfried Herder are not only striking in their vehement opposition to European imperialism. They arguably present the first attempt to ground anti-imperialism not just morally but epistemologically. Herder does this through his encounter with Kant’s precritical theory, augmented by a novel philosophy of language. Herder believed philosophy needs to reformulate its aims in terms of anthropology, history, and aesthetics. In the process, he found himself facing what I am calling the antinomy of universal reason. Reason is a universal characteristic of humanity. In its expressions, however, reason is plural and diverse. This antinomy has carried through into postcolonial theory, where it presents some serious epistemological and methodological challenges. Using the examples of Dipesh Chakrabarty, Achille Mbembe, and Gayatri Spivak, I show what these challenges look like. In conclusion, I inquire into Herder’s attempts to find a methodology that allows a critique of imperialism while recognizing the antinomous workings of universal reason.
Postcolonialism and the Historical Novel: Epistemologies of Contemporary Realism
Authors: Dalley Hamish
Published: February 2014

The historical novel is one of the most popular and critically significant genres of postcolonial writing, but, to date, almost no systematic scholarship is dedicated to it. This essay proposes theoretical and critical parameters for exploring this genre. It begins with the observation that plausibility is a key principle articulated by many postcolonial writers and explores how framing novels in these terms, as a kind of realism, requires readers to negotiate heterogeneous structures of reference—and, in particular, to read imaginary characters as abstractions of historical phenomena. The second half of the paper explores the theoretical implications of this ontological heterogeneity, suggesting how the genre’s conventions are inflected by normative patterns of gender, race, and temporality. Overall, I propose that it is possible to read the postcolonial historical novel as a kind of allegory, and I offer the term allegorical realism to describe this paradoxical mixing of conceptual and affective knowledge.