bluuebunny/crossref_metadata_2025 huggingface dataset:
What drives microplate motion and deformation in the northeastern Caribbean plate boundary region?
Authors: van Benthem Steven , Govers Rob , Wortel Rinus
Published: May 2014

The north Caribbean plate boundary zone is a broad deformation zone with several fault systems and tectonic blocks that move with different velocities. The indentation by the Bahamas Platform (the “Bahamas Collision”) is generally invoked as a cause of this fragmentation. We propose that a second driver of deformation is the western edge of the south dipping Puerto Rico slab moving sideways with the North America plate. The westward motion of the slab edge results in a push on the Caribbean plate farther west. We refer to this second mechanism for deformation as “Slab Edge Push.” The motion of the North America plate relative to the Caribbean plate causes both drivers to migrate from east to west. The Bahamas Collision and Slab Edge Push have been operating simultaneously since the Miocene. The question is the relative importance of the two mechanisms. We use mechanical finite element models that represent the two mechanisms from the late Oligocene (30 Ma) to the present. For the present, both models successfully reproduce observed deformation, implying that both models are viable. Back in time the Slab Edge Push mechanism better reproduces observations. Neither mechanism successfully reproduces the observed Miocene counterclockwise rotation of Puerto Rico. We use this rotation to tune a final model that includes fractional contributions of both mechanisms. We find that the Slab Edge Push was the dominant driver of deformation in the north Caribbean plate boundary zone since 30 Ma.
Gold‐Nanorod‐Assisted Near‐Infrared Stimulation of Primary Auditory Neurons
Authors: Yong Jiawey , Needham Karina , Brown William G. A. , Nayagam Bryony A. , McArthur Sally L. , Yu Aimin , Stoddart Paul R.
Published: May 2014

Infrared stimulation offers an alternative to electrical stimulation of neuronal tissue, with potential for direct, non‐contact activation at high spatial resolution. Conventional methods of infrared neural stimulation (INS) rely on transient heating due to the absorption of relatively intense laser beams by water in the tissue. However, the water absorption also limits the depth of penetration of light in tissue. Therefore, the use of a near‐infrared laser at 780 nm to stimulate cultured rat primary auditory neurons that are incubated with silica‐coated gold nanorods (Au NRs) as an extrinsic absorber is investigated. The laser‐induced electrical behavior of the neurons is observed using whole‐cell patch clamp electrophysiology. The nanorod‐treated auditory neurons (NR‐ANs) show a significant increase in electrical activity compared with neurons that are incubated with non‐absorbing silica‐coated gold nanospheres and control neurons with no gold nanoparticles. The laser‐induced heating by the nanorods is confirmed by measuring the transient temperature increase near the surface of the NR‐ANs with an open pipette electrode. These findings demonstrate the potential to improve the efficiency and increase the penetration depth of INS by labeling nerves with Au NRs and then exposing them to infrared wavelengths in the water window of tissue.
The association between cardiovascular risk factors and high blood pressure in adolescents: A school‐based study
Authors: Christofaro Diego G.D. , Fernandes Rômulo A. , Oliveira Arli R. , Freitas Júnior Ismael Forte , Barros Mauro V.G. , Ritti‐Dias Raphael M.
Published: May 2014

Objective

Although previous studies have analyzed the association between cardiovascular risk factors and blood pressure in adolescents, few studies conducted in developing countries analyzed whether the aggregation of risk factors contributes to an increased risk of high blood pressure in adolescents. The objective of this study was to assess the association between cardiovascular risk factors (including general overweight, abdominal obesity, high consumption of foods rich in fats, and insufficient physical activity levels) and high blood pressure in adolescents.

Methods

This study was carried out from 2007 to 2008 with 1021 adolescents (528 girls) from primary schools located in the city of Londrina‐ Brazil. Blood pressure was assessed using an oscillometric device. General overweight was obtained through body mass index, abdominal obesity was assessed using waist circumference, and the consumption of foods rich in fat and physical activity were assessed using a questionnaire. The sum of these risk factors was determined.

Results

Adolescents with three or four aggregated risk factors were more likely to have higher values of systolic and diastolic blood pressure when compared with adolescents who did not have any cardiovascular risk factors (P = 0.001 for both). Logistic regression indicated that groups of adolescents with 2 (OR= 2.46 [1.11–5.42]; P = 0.026), 3 (OR= 4.97 [2.07–11.92]; P = 0.001) or 4 risk factors (OR= 6.79 [2.24–19.9]; P = 0.001) presented an increased likelihood of high blood pressure.

Conclusions

The number of cardiovascular risk factors was found to be related to high blood pressure in adolescents. Am. J. Hum. Biol. 26:518–522, 2014. © 2014 Wiley Periodicals, Inc.
Zinc sulfide nanoparticles template by bacterial cellulose and their optical properties
Authors: Zheng Weili , Chen Shiyan , Zhao Siyu , Zheng Yi , Wang Huaping
Published: May 2014

Spherical zinc sulfide (ZnS) nanoparticles dispersed on bacterial cellulose (BC) nanofibers homogeneously were successfully fabricated through in situ precipitation method using BC as template and explored the formation mechanism. The structure and properties were characterized by Fourier transform infrared, X‐ray diffractometer, FESEM, and so on. The results demonstrated that the nanoparticles were sphalerite structure ZnS and the size increased with the increase of the zinc precursor concentrations. Moreover, a high photocatalytic activity (92%) for degradation of methyl orange was observed and the photoluminescence spectra of the nanocomposites exhibited a blue emission band centered at 468 nm. The flexible BC membrane carried of ZnS nanoparticles might be a promising candidate in the application fields of fluorescence and photo‐catalysis. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40874.
Schadensmodelle für extreme Hochwasser – Teil 2: Erste Schlussfolgerungen aus dem Ereignis vom Juni 2013
Authors: Maiwald Holger , Schwarz Jochen
Published: May 2014

Das Hochwasserereignis 2013 hat erneut schwere Schäden in den vom Hochwasser 2002 betroffenen Gebieten verursacht. Anhand einer Schadensdokumentation, welche sich auf das Einzugsgebiet der Vereinigten Mulde und der Zwickauer Mulde und somit auf die besonders betroffenen Überflutungsgebiete während des Hochwassers in Sachsen konzentriert, werden erste Schlussfolgerungen über die Auswirkungen von zwei Extremhochwassern an einem wiederholt betroffenen Bauwerksbestand gezogen.

Die Auswertung der aufgetretenen Schäden erlaubt eine weitere Plausibilisierung des am Zentrum für die Ingenieuranalyse von Erdbebenschäden (EDAC) der Bauhaus‐Universität Weimar entwickelten Schadensmodells.

In den schon 2002 betroffenen sächsischen Untersuchungsgebieten Döbeln, Eilenburg und Grimma werden die Schäden und die aufgetretenen Wasserstände dokumentiert. Mit neu entwickelten Verletzbarkeits‐ und Schadensfunktionen werden Prognosen der aufgetretenen Schäden und Verluste möglich, die sich später mit den offiziell gemeldeten Schadenssummen korrelieren lassen.

Die Auswirkungen der Wiederherstellungsmaßnahmen nach dem Hochwasser 2002 auf die Verletzbarkeit des Bauwerksbestandes werden dabei herausgestellt und daraus resultierende Veränderungen bei der Prognose der Verluste differenziert berücksichtigt.

Damage models for extreme flood events – Part 2: Preliminary conclusions from the event in June 2013

The 2013 flood event caused severe damage again in the areas affected by the 2002 flood. Based on a damage documentation along the river basin of Vereinigte Mulde and Zwickauer Mulde, and therefore concentrated on the most affected areas during the flood in Saxony, some preliminary conclusions are drawn about the impact of two extreme floods on a repeated affected building stock.

The evaluation of the observed damages allows a further plausibility of the flood damage model which was developed at the Earthquake Damage Analysis Center (EDAC) at the Bauhaus‐Universität Weimar.

In the study areas Döbeln, Eilenburg and Grimma in Saxony, already affected by the 2002 flood, the observed damages and the flood heights are documented. Newly developed vulnerability and damage functions enable the prediction of the damages and losses, which can be correlated later with the official reported losses.

The effects of recovery measures after the 2002 flood on the vulnerability of the building stock are highlighted and the resulting changes are taken into account differentiated by the prediction of the losses.
Environmental Policy in the Nordic Wood Product Industry: Insights Into Firms’ Strategies and Communication
Authors: Räty Tarmo , Toppinen Anne , Roos Anders , Riala Maria , Nyrud Anders Q.
Published: May 2014

The purpose of our study is to explore how companies operating in the Nordic wood products value chains currently use environmental performance measures in their environmental policy and communication with stakeholders. Apart from the regularly‐used environmental management certificates, the ability of wood material to store carbon and the use of sustainable forest management certificates open up interesting strategic options for firms in the implementation of their environmental policy. The primary was collected through thematic managerial interviews in 2011 from 37 companies in Finland, Sweden and Norway, of varying size, roles in the value chain, conditions for green business practices and exports. Forest certification and environmental management systems were frequently used, but managers did not always perceive them to be useful, particularly for raising environmental awareness at the final consumer level. Nevertheless, the general attitude towards using environmental performance measures was seen as positive. Companies with a business‐to‐business orientation were the most proactive in terms of environmental communication, whereas companies in consumer markets were more reactive. The key stakeholders targeted for environmental communication were value chain partners and the authorities, and only to a lesser degree employees and environmental non‐governmental organisations. The key strategic role of environmental management and communication appeared to be securing the firms against negative environmental claims. The Nordic wood industry could improve their communication if the strategic orientation is shifted from the forest certification to the use of generic eco‐labels, and most of all, to the adoption of quantitative measures like carbon footprints and environmental product declarations. Copyright © 2014 John Wiley & Sons, Ltd and ERP Environment.
Crosslinked enzyme aggregates of hydroxynitrile lyase partially purified from Prunus dulcis seeds and its application for the synthesis of enantiopure cyanohydrins
Authors: Yildirim Deniz , Tükel S. Seyhan , Alagöz Dilek
Published: May 2014

Hydroxynitrile lyases are powerful catalysts in the synthesis of enantiopure cyanohydrins which are key synthons in the preparations of a variety of important chemicals. The response surface methodology including three‐factor and three‐level Box–Behnken design was applied to optimize immobilization of hydroxynitrile lyase purified partially from Prunus dulcis seeds as crosslinked enzyme aggregates (PdHNL‐CLEAs). The quadratic model was developed for predicting the response and its adequacy was validated with the analysis of variance test. The optimized immobilization parameters were initial glutaraldehyde concentration, ammonium sulfate saturation concentration, and crosslinking time, and the response was relative activity of PdHNL‐CLEA. The optimal conditions were determined as initial glutaraldehyde concentration of 25% w/v, ammonium sulfate saturation concentration of 43% w/v, and crosslinking time of 18 h. The preparations of PdHNL‐CLEA were examined for the synthesis of (R)‐mandelonitrile, (R)‐2‐chloromandelonitrile, (R)‐3,4‐dihydroxymandelonitrile, (R)‐2‐hydroxy‐4‐phenyl butyronitrile, (R)‐4‐bromomandelonitrile, (R)‐4‐fluoromandelonitrile, and (R)‐4‐nitromandelonitrile from their corresponding aldehydes and hydrocyanic acid. After 96‐h reaction time, the yield–enantiomeric excess values (%) were 100−99, 100−21, 100−99, 83−91, 100−99, 100−72, and 100−14%, respectively, for (R)‐mandelonitrile, (R)‐2‐chloromandelonitrile, (R)‐3,4‐dihydroxymandelonitrile, (R)‐2‐hydroxy‐4‐phenyl butyronitrile, (R)‐4‐bromomandelonitrile, (R)‐4‐fluoromandelonitrile, and (R)‐4‐nitromandelonitrile. The results show that PdHNL‐CLEA offers a promising potential for the preparation of enantiopure (R)‐mandelonitrile, (R)‐3,4‐dihydroxymandelonitrile, (R)‐2‐hydroxy‐4‐phenyl butyronitrile, and (R)‐4‐bromomandelonitrile with a high yield and enantiopurity. © 2014 American Institute of Chemical Engineers Biotechnol. Prog, 30:818–827, 2014
Nickel‐Based Anode with Water Storage Capability to Mitigate Carbon Deposition for Direct Ethanol Solid Oxide Fuel Cells
Authors: Wang Wei , Su Chao , Ran Ran , Zhao Bote , Shao Zongping , O. Tade Moses , Liu Shaomin
Published: May 2014

The potential to use ethanol as a fuel places solid oxide fuel cells (SOFCs) as a sustainable technology for clean energy delivery because of the renewable features of ethanol versus hydrogen. In this work, we developed a new class of anode catalyst exemplified by Ni+BaZr0.4Ce0.4Y0.2O3 (Ni+BZCY) with a water storage capability to overcome the persistent problem of carbon deposition. Ni+BZCY performed very well in catalytic efficiency, water storage capability and coking resistance tests. A stable and high power output was well maintained with a peak power density of 750 mW cm−2 at 750 °C. The SOFC with the new robust anode performed for seven days without any sign of performance decay, whereas SOFCs with conventional anodes failed in less than 2 h because of significant carbon deposition. Our findings indicate the potential applications of these water storage cermets as catalysts in hydrocarbon reforming and as anodes for SOFCs that operate directly on hydrocarbons.
Using dynamic N‐mixture models to test cavity limitation on northern flying squirrel demographic parameters using experimental nest box supplementation
Authors: Priol Pauline , Mazerolle Marc J. , Imbeau Louis , Drapeau Pierre , Trudeau Caroline , Ramière Jessica
Published: May 2014

Dynamic N‐mixture models have been recently developed to estimate demographic parameters of unmarked individuals while accounting for imperfect detection. We propose an application of the Dail and Madsen (: Biometrics, 67, 577–587) dynamic N‐mixture model in a manipulative experiment using a before‐after control‐impact design (BACI). Specifically, we tested the hypothesis of cavity limitation of a cavity specialist species, the northern flying squirrel, using nest box supplementation on half of 56 trapping sites. Our main purpose was to evaluate the impact of an increase in cavity availability on flying squirrel population dynamics in deciduous stands in northwestern Québec with the dynamic N‐mixture model. We compared abundance estimates from this recent approach with those from classic capture–mark–recapture models and generalized linear models. We compared apparent survival estimates with those from Cormack–Jolly–Seber (CJS) models. Average recruitment rate was 6 individuals per site after 4 years. Nevertheless, we found no effect of cavity supplementation on apparent survival and recruitment rates of flying squirrels. Contrary to our expectations, initial abundance was not affected by conifer basal area (food availability) and was negatively affected by snag basal area (cavity availability). Northern flying squirrel population dynamics are not influenced by cavity availability at our deciduous sites. Consequently, we suggest that this species should not be considered an indicator of old forest attributes in our study area, especially in view of apparent wide population fluctuations across years. Abundance estimates from N‐mixture models were similar to those from capture–mark–recapture models, although the latter had greater precision. Generalized linear mixed models produced lower abundance estimates, but revealed the same relationship between abundance and snag basal area. Apparent survival estimates from N‐mixture models were higher and less precise than those from CJS models. However, N‐mixture models can be particularly useful to evaluate management effects on animal populations, especially for species that are difficult to detect in situations where individuals cannot be uniquely identified. They also allow investigating the effects of covariates at the site level, when low recapture rates would require restricting classic CMR analyses to a subset of sites with the most captures.
Developmental changes in the skull morphology of common minke whales Balaenoptera acutorostrata
Authors: Nakamura Gen , Kato Hidehiro
Published: May 2014

We investigated growth‐related and sex‐related morphological changes in the skulls of 144 North Pacific common minke whales Balaenoptera acutorostrata. Measurement was conducted at 39 points on the skull and mandible to extract individual allometric equations relating the length and zygomatic width of the skull. The results revealed no significant differences in skull morphology by sex except for width of occipital bone. The size relative to the skull of the anatomical parts involved in feeding, such as the rostrum and mandible, increased after birth. In contrast, the sensory organs and the anatomical regions involved in neurological function, such as the orbit, tympanic bullae, and foramen magnum, were fully developed at birth, and their relative size reduced over the course of development. This is the first study to investigate developmental changes in the skull morphology using more than 100 baleen whale specimens, and we believe the results of this study will contribute greatly to multiple areas of baleen whale research, including taxonomy and paleontology. J. Morphol. 275:1113–1121, 2014. © 2014 Wiley Periodicals, Inc.
Critical neuroprotective roles of heme oxygenase‐1 induction against axonal injury‐induced retinal ganglion cell death
Authors: Himori Noriko , Maruyama Kazuichi , Yamamoto Kotaro , Yasuda Masayuki , Ryu Morin , Omodaka Kazuko , Shiga Yukihiro , Tanaka Yuji , Nakazawa Toru
Published: May 2014

Although axonal damage induces significant retinal ganglion cell (RGC) death, small numbers of RGCs are able to survive up to 7 days after optic nerve crush (NC) injury. To develop new treatments, we set out to identify patterns of change in the gene expression of axonal damage‐resistant RGCs. To compensate for the low density of RGCs in the retina, we performed retrograde labeling of these cells with 4Di‐10ASP in adult mice and 7 days after NC purified the RGCs with fluorescence‐activated cell sorting. Gene expression in the cells was determined with a microarray, and the expression of Ho‐1 was determined with quantitative PCR (qPCR). Changes in protein expression were assessed with immunohistochemistry and immunoblotting. Additionally, the density of Fluoro‐gold‐labeled RGCs was counted in retinas from mice pretreated with CoPP, a potent HO‐1 inducer. The microarray and qPCR analyses showed increased expression of Ho‐1 in the post‐NC RGCs. Immunohistochemistry also showed that HO‐1‐positive cells were present in the ganglion cell layer (GCL), and cell counting showed that the proportion of HO‐1‐positive cells in the GCL rose significantly after NC. Seven days after NC, the number of RGCs in the CoPP‐treated mice was significantly higher than in the control mice. Combined pretreatment with SnPP, an HO‐1 inhibitor, suppressed the neuroprotective effect of CoPP. These results reflect changes in HO‐1 activity to RGCs that are a key part of RGC survival. Upregulation of HO‐1 signaling may therefore be a novel therapeutic strategy for glaucoma. © 2014 Wiley Periodicals, Inc.
Celecoxib prevents curcumin‐induced apoptosis in a hematopoietic cancer cell model
Authors: Sobolewski Cyril , Muller Florian , Cerella Claudia , Dicato Mario , Diederich Marc
Published: May 2014

Molecules targeting pro‐inflammatory pathways have demonstrated beneficial effects in cancer treatment. More recently, combination of natural and synthetic anti‐inflammatory drugs was suggested as an appealing strategy to inhibit tumor growth. Herein, we show that curcumin, a polyphenol from Curcuma longa and celecoxib induce apoptosis in hematopoietic cancer cell lines (Hel, Jurkat, K562, Raji, and U937). Further investigations on the most sensitive cell line, U937, indicated that these effects were tightly associated with an accumulation of the cells in S and G2/M for curcumin and in G0/G1 phase of cell cycle for celecoxib, respectively. The effect of celecoxib on cell cycle is associated with an induction of p27 and the down‐regulation of cyclin D1. However, in the case of combination experiments, the pretreatment of U937 cells with celecoxib at non‐apoptogenic concentrations counteracted curcumin‐induced apoptosis. We found that this effect correlated with the prevention of the accumulation in S and G2/M phase of cell cycle induced by curcumin. Similar results have been obtained when celecoxib and curcumin were co‐administrated at the same time. Overall our data suggest that this natural and synthetic drug combination is detrimental for cell death induction. © 2014 Wiley Periodicals, Inc.
Intratumor mapping of intracellular water lifetime: metabolic images of breast cancer?
Authors: Springer Charles S. , Li Xin , Tudorica Luminita A. , Oh Karen Y. , Roy Nicole , Chui Stephen Y‐C. , Naik Arpana M. , Holtorf Megan L. , Afzal Aneela , Rooney William D. , Huang Wei
Published: May 2014

Shutter‐speed pharmacokinetic analysis of dynamic‐contrast‐enhanced (DCE)‐MRI data allows evaluation of equilibrium inter‐compartmental water interchange kinetics. The process measured here – transcytolemmal water exchange – is characterized by the mean intracellular water molecule lifetime (τi). The τi biomarker is a true intensive property not accessible by any formulation of the tracer pharmacokinetic paradigm, which inherently assumes it is effectively zero when applied to DCE‐MRI. We present population‐averaged in vivo human breast whole tumor τi changes induced by therapy, along with those of other pharmacokinetic parameters. In responding patients, the DCE parameters change significantly after only one neoadjuvant chemotherapy cycle: while Ktrans (measuring mostly contrast agent (CA) extravasation) and kep (CA intravasation rate constant) decrease, τi increases. However, high‐resolution, (1 mm)2, parametric maps exhibit significant intratumor heterogeneity, which is lost by averaging. A typical 400 ms τi value means a trans‐membrane water cycling flux of 1013 H2O molecules s−1/cell for a 12 µm diameter cell. Analyses of intratumor variations (and therapy‐induced changes) of τi in combination with concomitant changes of ve (extracellular volume fraction) indicate that the former are dominated by alterations of the equilibrium cell membrane water permeability coefficient, PW, not of cell size. These can be interpreted in light of literature results showing that τi changes are dominated by a PW(active) component that reciprocally reflects the membrane driving P‐type ATPase ion pump turnover. For mammalian cells, this is the Na+,K+‐ATPase pump. These results promise the potential to discriminate metabolic and microenvironmental states of regions within tumors in vivo, and their changes with therapy. © 2014 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.
The activating receptor NKG2D of natural killer cells promotes resistance against enterovirus‐mediated inflammatory cardiomyopathy
Authors: Klingel Karin , Fabritius Cornelia , Sauter Martina , Göldner Katrin , Stauch Diana , Kandolf Reinhard , Ettischer Nicole , Gahlen Sabine , Schönberger Tanja , Ebner Susanne , Makrigiannis Andrew P , Bélanger Simon , Diefenbach Andreas , Polić Bojan , Pratschke Johann , Kotsch Katja
Published: May 2014

In enterovirus‐induced cardiomyopathy, information regarding the detailed impact of natural killer (NK) cells on the outcome of the disease is limited. We therefore hypothesized that NK cells and certain NK cell receptors determine the different outcome of coxsackievirus B3 (CVB3) myocarditis. Here, we demonstrate in murine models that resistance to chronic CVB3 myocarditis in immunocompetent C57BL/6 mice is characterized by significantly more mature CD11bhigh NK cells, the presence of NKG2D on NK cells, and enhanced NKG2D‐dependent cytotoxicity compared to CVB3‐susceptible A.BY/SnJ mice. The highly protective role of NKG2D in myocarditis was further proven by in vivo neutralization of NKG2D as well as in NKG2D‐deficient mice but was shown to be independent of CD8+ T‐cell‐dependent immunity. Moreover, the adoptive transfer of immunocompetent C57BL/6 NK cells pre‐ (day −1) as well as post‐infectionem (day +2) displayed the potential to prevent permissive A.BY/SnJ mice from a progressive outcome of CVB3 myocarditis reflected by significantly improved cardiopathology and heart function. Altogether, our results provide firm evidence for a protective role of NKG2D‐activated NK cells in CVB3 myocarditis leading to an effective virus clearance, thus offering novel therapeutic options in the treatment of virus‐induced myocarditis. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd
Co‐optimization of SnS absorber and Zn(O,S) buffer materials for improved solar cells
Authors: Park Helen Hejin , Heasley Rachel , Sun Leizhi , Steinmann Vera , Jaramillo Rafael , Hartman Katy , Chakraborty Rupak , Sinsermsuksakul Prasert , Chua Danny , Buonassisi Tonio , Gordon Roy G.
Published: May 2014

Thin‐film solar cells consisting of earth‐abundant and non‐toxic materials were made from pulsed chemical vapor deposition (pulsed‐CVD) of SnS as the p‐type absorber layer and atomic layer deposition (ALD) of Zn(O,S) as the n‐type buffer layer. The effects of deposition temperature and annealing conditions of the SnS absorber layer were studied for solar cells with a structure of Mo/SnS/Zn(O,S)/ZnO/ITO. Solar cells were further optimized by varying the stoichiometry of Zn(O,S) and the annealing conditions of SnS. Post‐deposition annealing in pure hydrogen sulfide improved crystallinity and increased the carrier mobility by one order of magnitude, and a power conversion efficiency up to 2.9% was achieved. Copyright © 2014 John Wiley & Sons, Ltd.
Comparison of thin epitaxial film silicon photovoltaics fabricated on monocrystalline and polycrystalline seed layers on glass
Authors: Teplin Charles W. , Grover Sachit , Chitu Adrian , Limanov Alexander , Chahal Monical , Im James , Amkreutz Daniel , Gall Stefan , Yoon Heayoung P. , Lasalvia Vincenzo , Stradins Paul , Jones Kim M. , Norman Andrew G. , Young David L. , Branz Howard M. , Lee Benjamin G.
Published: May 2014

We fabricate thin epitaxial crystal silicon solar cells on display glass and fused silica substrates overcoated with a silicon seed layer. To confirm the quality of hot‐wire chemical vapor deposition epitaxy, we grow a 2‐µm‐thick absorber on a (100) monocrystalline Si layer transfer seed on display glass and achieve 6.5% efficiency with an open circuit voltage (VOC) of 586 mV without light‐trapping features. This device enables the evaluation of seed layers on display glass. Using polycrystalline seeds formed from amorphous silicon by laser‐induced mixed phase solidification (MPS) and electron beam crystallization, we demonstrate 2.9%, 476 mV (MPS) and 4.1%, 551 mV (electron beam crystallization) solar cells. Grain boundaries likely limit the solar cell grown on the MPS seed layer, and we establish an upper bound for the grain boundary recombination velocity (SGB) of 1.6x104 cm/s. Copyright © 2014 John Wiley & Sons, Ltd.
Determination of rare earth elements in saline matrices using dispersed particle extraction and inductively coupled plasma mass spectrometry
Authors: Janski Rafael , Neouze Marie‐Alexandra , Limbeck Andreas
Published: May 2014

RATIONALE

Rare earth elements play an important role in identifying and indexing the origin of historical and geological samples. In this work, a new approach for the characterization of rare earth elements (REEs) in aqueous sample solutions with high salinity is presented.

METHODS

Prior to analysis by inductively coupled plasma mass spectrometry (ICP‐MS) the target analytes were separated from interfering matrix constituents by the use of surface‐functionalized nanoparticles. Compared with common matrix separation techniques, such as solid‐phase extraction (SPE), the strength of the method lies in the combination of an advanced extraction procedure with internal standard correction. Thus, known limitations of SPE such as column clogging or incomplete analyte elution could be completely circumvented. Furthermore, time‐consuming approaches for signal quantification such as matrix‐matched calibration could be avoided since the applied internal standard allows the correction of matrix‐induced deviations in sample extraction and ICP‐MS analysis.

RESULTS

With the developed procedure detection limits <1 ng L−1 could be achieved for all the investigated elements, with satisfactory relative standard deviations (RSDs) of 3–26% for unspiked samples and <1–2% for spiked samples. Results derived from recovery experiments with spiked oil accumulation water samples confirmed the applicability of the proposed procedure for the determination of REEs in highly saline sample solutions. The procedure was successfully applied to the study of oil accumulation water samples from different oil fields in Lower Austria.

CONCLUSIONS

A sample pretreatment procedure with subsequent ICP‐MS analysis for the accurate determination of REEs in aqueous sample solutions with high salinity has been developed. Copyright © 2014 John Wiley & Sons, Ltd.
Comparison at the peptide level with post‐translational modification consideration reveals more differences between two unenriched samples
Authors: Yin Jianrui , Shao Chen , Jia Lulu , Gao Youhe
Published: May 2014

RATIONALE

In shotgun strategies, peptide sequences are first identified from tandem mass (MS/MS) spectra, and the existence and abundance of the proteins are then inferred from the peptide information. However, the protein inference step can produce errors and a loss of information. To identify the information that is lost using the traditional approaches, this study compared the proteomic data of two leukemia cell lines (Jurkat and K562) at the peptide level with consideration of post‐translational modifications (PTMs).

METHODS

The raw files from the two cell lines were searched against the decoy IPI‐human database version 3.68, which contains forward and reverse sequences. Then the observed modification name in the results was matched with the modification classification on the Unimod website by a manual search. Only the peptides with ‘post‐translational’ modifications were compared between the two cell lines.

RESULTS

After searching the database with consideration of PTMs, a total of 44046 non‐redundant peptides were identified in both the Jurkat and K562 cell lines. Of these peptides, even without specific PTM enrichment, 11.43% of them (with at least two spectra in one cell line) existed in different PTM forms between the two cell lines, and 1.73% of the peptides were modified in both cell lines, but with different modifications or possibly on different sites.

CONCLUSIONS

Comparing proteomic data at the peptide level with consideration of PTMs can reveal more differences between two unenriched samples. Copyright © 2014 John Wiley & Sons, Ltd.
Fragmentation reactions of N‐benzyltetrahydroquinolines in electrospray ionization mass spectrometry: the roles of ion/neutral complex intermediates
Authors: Guo Cheng , Jiang Kezhi , Zheng Shu
Published: May 2014

RATIONALE

Electrospray ionization mass spectrometry (ESI‐MS) combined with the collision‐induced dissociation (CID) technique has assumed increasing importance as an invaluable tool for the structural analysis of organic and biological molecules. However, general rules for elucidating the fragmentation behaviors of charged molecules in the gas phase are still lacking. Therefore, explorations on the mechanistic information are desirable at all times.

METHODS

CID experiments of protonated N‐benzyltetrahydroquinolines were carried out on ESI ion trap mass spectrometer and accurate mass measurements were performed on a high‐resolution ESI quadrupole time‐of‐flight (Q‐TOF) mass spectrometer in positive ion mode.

RESULTS

An ion/neutral complex, [RC6H4CH2+/tetrahydroquinoline], resulting from cleavage of the C–N bond induced by the positive charge brought in by protonation, was proposed to be the intermediate to elucidate the fragmentation reactions. For all the compounds investigated, benzyl cation transfer, electron transfer and hydride transfer reactions mediated by the complex were observed. Moreover, for the compound substituted by a methyl group at the para‐position of the benzylic phenyl ring, proton transfer reaction via the complex also occurs.

CONCLUSIONS

This study is a case for better understanding the intriguing roles of ion/neutral complexes in gas‐phase fragmentation reactions and enriching the knowledge about the gas‐phase chemistry of the benzyl cation. In addition, it provides useful information for researchers working on analysis or structural elucidation of complicated compounds which contain the N‐benzyltetrahydroquinoline substructure. Copyright © 2014 John Wiley & Sons, Ltd.
A versatile method for simultaneous stable carbon isotope analysis of DNA and RNA nucleotides by liquid chromatography/isotope ratio mass spectrometry
Authors: Moerdijk‐Poortvliet Tanja C. W. , Brasser Jurian , de Ruiter Gerjan , Houtekamer Marco , Bolhuis Henk , Stal Lucas J. , Boschker Henricus T. S.
Published: May 2014

RATIONALE

Liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) is currently the most accurate and precise technique for the measurement of compound‐specific stable carbon isotope ratios (13C/12C) in biological metabolites, at their natural abundance. However, until now this technique could not be applied for the analysis of nucleic acids, the building blocks of the carriers of genetic information in living cells and viruses, DNA and RNA.

METHODS

Mixed‐mode chromatography (MMC) was applied to obtain the complete separation of nine nucleotides (eight originating from DNA/RNA and one nucleotide (inosine monophosphate) that may serve as an internal standard) in a single run using LC/IRMS. We also developed and validated a method for DNA and RNA extraction and an enzymatic hydrolysis protocol for natural samples, which is compatible with LC/IRMS analysis as it minimizes the carbon blank. The method was used to measure the concentration and stable carbon isotope ratio of DNA and RNA nucleotides in marine sediment and in the common marine macro alga (Ulva sp.) at natural abundance levels as well as for 13C‐enriched samples.

RESULTS

The detection limit of the LC/IRMS method varied between 1.0 nmol for most nucleotides and 2.0 nmol for late‐eluting compounds. The intraday and interday reproducibility of nucleotide concentration measurements was better than, respectively, 4.1% and 8.9% and for δ13C measurements better than, respectively, 0.3‰ and 0.5‰. The obtained nucleic acid concentrations and nucleic acid synthesis rates were in good agreement with values reported in the literature.

CONCLUSIONS

This new method gives reproducible results for the concentration and δ13C values of nine nucleotides. This solvent‐free chromatographic method may also be used for other purposes, such as for instance to determine nucleotide concentrations using spectrophotometric detection. This sensitive method offers a new avenue for the study of DNA and RNA biosynthesis that can be applied in various fields of research. Copyright © 2014 John Wiley & Sons, Ltd.
Small sample GEE estimation of regression parameters for longitudinal data
Authors: Paul Sudhir , Zhang Xuemao
Published: May 2014

Longitudinal (clustered) response data arise in many bio‐statistical applications which, in general, cannot be assumed to be independent. Generalized estimating equation (GEE) is a widely used method to estimate marginal regression parameters for correlated responses. The advantage of the GEE is that the estimates of the regression parameters are asymptotically unbiased even if the correlation structure is misspecified, although their small sample properties are not known. In this paper, two bias adjusted GEE estimators of the regression parameters in longitudinal data are obtained when the number of subjects is small. One is based on a bias correction, and the other is based on a bias reduction. Simulations show that the performances of both the bias‐corrected methods are similar in terms of bias, efficiency, coverage probability, average coverage length, impact of misspecification of correlation structure, and impact of cluster size on bias correction. Both these methods show superior properties over the GEE estimates for small samples. Further, analysis of data involving a small number of subjects also shows improvement in bias, MSE, standard error, and length of the confidence interval of the estimates by the two bias adjusted methods over the GEE estimates. For small to moderate sample sizes (), either of the bias‐corrected methods GEEBc and GEEBr can be used. However, the method GEEBc should be preferred over GEEBr, as the former is computationally easier. For large sample sizes, the GEE method can be used. Copyright © 2014 John Wiley & Sons, Ltd.
Target-controlled formation of silver nanoclusters in abasic site-incorporated duplex DNA for label-free fluorescence detection of theophylline
Authors: Park Ki Soo , Oh Seung Soo , Soh H. Tom , Park Hyun Gyu
Published: May 2014

A novel, label-free, fluorescence based sensor for the selective and sensitive detection of theophylline has been developed.
A simple aptamer biosensor for Salmonellae enteritidis based on fluorescence-switch signaling graphene oxide
Authors: Wu Wei , Fang Zhiyuan , Zhao Shiming , Lu Xuewen , Yu Luxin , Mei Ting , Zeng Lingwen
Published: May 2014

In this communication, we report a rapid and cost-efficient assay for the detection of S. enteritidis using a specific aptamer, which can detect as low as 40 CFU mL−1 of S. enteritidis in 30 min.
Capturing non-equilibrium phenomena in rarefied polyatomic gases: A high-order macroscopic model
Authors: Rahimi Behnam , Struchtrup Henning
Published: May 2014

A high-order macroscopic model for the accurate description of rarefied polyatomic gas flows is introduced based on a kinetic equation of Bhatnagar-Gross-Krook (BGK)-type, where the different energy exchange processes are accounted for by two collision terms. The order of magnitude method is applied to the primary moment equations to acquire the optimized moment definitions and the final scaled set of Grad's 36 moment equations for polyatomic gases. The two Knudsen numbers of the system are used for model reduction in terms of their powers, which yields a wide range of different reduced systems, a total of 13 different orders. These include, at lower order, a modification of the Navier-Stokes-Fourier (NSF) equations which shows considerable extended range of validity in comparison to the classical NSF equations. The highest order of accuracy considered gives a set of 18 regularized partial differential equations (PDEs) (R18). Attenuation and speed of linear waves are studied as the first application of the many sets of equations. For frequencies where the internal degrees of freedom are effectively frozen, the equations reproduce the behavior of monatomic gases.
Ge L3-edge x-ray absorption near-edge structure study of structural changes accompanying conductivity drift in the amorphous phase of Ge2Sb2Te5
Authors: Mitrofanov K. V. , Kolobov A. V. , Fons P. , Wang X. , Tominaga J. , Tamenori Y. , Uruga T. , Ciocchini N. , Ielmini D.
Published: May 2014

A gradual uncontrollable increase in the resistivity of the amorphous phase of phase-change alloys, such as Ge2Sb2Te5, known as drift, is a serious technological issue for application of phase-change memory. While it has been proposed that drift is related to structural relaxation, no direct structural results have been reported so far. Here, we report the results of Ge L3-edge x-ray absorption measurements that suggest that the drift in electrical conductivity is associated with the gradual conversion of tetrahedrally coordinated Ge sites into pyramidal sites, while the system still remains in the amorphous phase. Based on electronic configuration arguments, we propose that during this process, which is governed by the existence of lone-pair electrons, the concentration of free carriers in the system decreases resulting in an increase in resistance despite the structural relaxation towards the crystalline phase.
A study of the phase transition and magnetocaloric effect in multiferroic La2MnNiO6 single crystals
Authors: Balli M. , Fournier P. , Jandl S. , Gospodinov M. M.
Published: May 2014

Magnetic and magnetocaloric properties of single crystal double perovskite La2MnNiO6 have been investigated in details. Its ordered phase with a high Curie temperature (TC = 280 K) exhibits a significant refrigerant capacity around room temperature. A model based on the mean field theory approximation has been used in order to quantify the magnetic and magnetocaloric properties in the ordered La2MnNiO6. The magnetization and entropy changes were satisfactorily simulated as a function of temperature and magnetic field. On the other hand, the presence of cationic disorder in La2MnNiO6 phases allows to shift the Curie point to low temperature without a significant change in the magnetocaloric performance.
Hybrid solar cells with ZnO-nanorods and dry processed small molecule absorber
Authors: Riedel W. , Wiesner S. , Greiner D. , Hinrichs V. , Rusu M. , Lux-Steiner M. Ch.
Published: May 2014

We demonstrate hybrid solar cells with ZnO-nanorods (ZnO-NRs) prepared by a low temperature electrochemical method and small molecule organic absorber processed by dry organic vapor phase deposition. A homogeneous coverage of ZnO-NRs by the blend absorber consisting of zinc phthalocyanine (ZnPc) as donor and of fullerene C60 as acceptor is best realized when a thin C60 layer is first inserted at the ZnO-NR/ZnPc:C60 interface. ZnO-NR/C60/ZnPc:C60/MoO3/Ag solar cell devices with efficiencies of 2.8% under an illumination of 100 mW/cm2 at 25 °C are demonstrated.
Comparison of Y-chromosomal lineage dating using either evolutionary or genealogical Y-STR mutation rates
Authors: Wang Chuan-Chao , Hui Li
Published: May 2014

We have compared the Y chromosomal lineage dating between sequence data and commonly used Y-SNP plus Y-STR data. The coalescent times estimated using evolutionary Y-STR mutation rates correspond best with sequence-based dating when the lineages include the most ancient haplogroup A individuals. However, the times using slow mutated STR markers with genealogical rates fit well with sequence-based estimates in main lineages, such as haplogroup CT, DE, K, NO, IJ, P, E, C, I, J, N, O, and R. In addition, genealogical rates lead to more plausible time estimates for Neolithic coalescent sublineages compared with sequence-based dating.
Government Size, Government Debt and Economic Performance with Particular Application to New Zealand
Authors: Stephen Ferris J.
Published: May 2014

This analysis finds that long‐run government size and private per capita output have an inverted U‐shaped relationship, with the positive effect of government size peaking at close to 30 per cent of GDP. As larger debt is also associated with lower levels of private output, the recent policy of contraction in government size and debt in New Zealand has produced an output premium. The short‐run analysis suggests that the inverse relationship found between changes in government size and economic growth is attributable to counter‐cyclical fiscal policy. This reinforces the traditional role of fiscal policy in New Zealand while cautioning against longer‐run spillovers from larger government size and debt.
Decreased miR‐146 expression in peripheral blood mononuclear cells is correlated with ongoing islet autoimmunity in type 1 diabetes patients 1型糖尿病患者外周血单个核细胞miR‐146表达下调与胰岛持续免疫失衡相关
Authors: Yang Minglan , Ye Lei , Wang Bokai , Gao Jie , Liu Ruixin , Hong Jie , Wang Weiqing , Gu Weiqiong , Ning Guang
Published: May 2014

Background

Type 1 diabetes mellitus (T1D) is a common autoimmune disease mediated by autoimmune attack against pancreatic β‐cells. It has been reported that dysregulation of microRNAs (miRNAs) may contribute to the pathogenesis of autoimmune diseases, including T1D. The aim of the present study was to identify pathogenic miRNAs in peripheral blood mononuclear cells (PBMC) of T1D patients.

Methods

Global miRNA and mRNA expression was profiled in PBMC from 12 patients with newly diagnosed T1D and 10 normal controls. Differently expressed miRNAs were validated in an independent set of patients and controls. The dynamic changes in miRNA and target gene expression were analyzed in T1D patients treated with either a short (6 months) or long (12–24 months) course of insulin. The association between miRNA expression and serum glutamic acid decarboxylase antibody (GADA) titers was also investigated.

Results

Compared with normal controls, there were 26 miRNAs and 1218 genes differently expressed in PBMC of patients with newly diagnosed T1D. The greatest downregulation was for miR‐146a (48% decrease; P < 0.05). Expression of its target genes, predicted to be tumor necrosis factor receptor‐associated factor 6 (TRAF6), B cell CLL/lymphoma 11A (BCL11A), syntaxin 3 (STX3) and numb homolog (NUMB), was upregulated. Moreover, T1D patients on long‐course insulin and optimized glucose control had sustained low expression of miR‐146. Interestingly, decreased miR‐146a expression was significantly associated with high serum GADA titers (P < 0.05).

Conclusions

The results suggest that dysregulation of miR‐146 expression in PBMC may be associated with the ongoing autoimmune imbalance in T1D patients.