bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxidation of a novel CeO2‐dispersed chromium coating in wet air
Authors: Peng X. , Yan J. , Zheng L. , Wang F.
Published: January 2011

An electrodeposited Ni–CeO2 composite was used as a “precursor film” for a novel CeO2‐dispersed chromium coating deposited using a traditional pack cementation method. The substrate was a carbon steel. For comparison, chromium coatings were also prepared on the untreated and pure Ni‐film‐treated carbon steel using the same pack cementation conditions. Oxidation in 5% O2 + 40% H2O + N2 at 900 °C showed that, compared to the CeO2‐free coating counterparts, the CeO2‐dispersed chromium coating exhibited greatly increased oxidation resistance, owing to the development of a denser and more slowly growing chromia scale. The slow growth of the scale was correlated with the CeO2 dispersion exerting the so‐called “reactive elemental effect (REE)” on oxidation. The oxidation mechanisms in wet air of the various types of coatings were compared to those in dry air and are fully discussed in this work.
Modelling of the oxide scale formation on Fe‐Cr steel during exposure in liquid lead‐bismuth eutectic in the 450–600 °C temperature range
Authors: Martinelli L. , Balbaud‐Célérier F.
Published: January 2011

Previous studies showed that the oxidation of T91 (Fe‐9Cr martensitic steel) in liquid Pb‐Bi eutectic leads to the formation of a duplex oxide layer containing an inner Fe2.3Cr0.7O4 spinel layer and an upper magnetite layer. The magnetite layer is easily removed by the Pb‐Bi flow when the oxygen concentration is low and the flow velocity is high. This phenomenon is not currently understood. The magnetite layer growth rate is limited by the iron diffusion in the oxide layer lattice. The Fe‐Cr spinel layer grows in the nanometric cavities formed at the Fe‐Cr spinel /T91 interface by the outwards diffusion of iron. Due to this mechanism the growth rate of the Fe‐Cr spinel layer is linked to that of magnetite. A modelling of this mechanism is presented. The modelling is in agreement with the experimental data in the case of a high oxygen concentration. However, the calculated oxide scale thicknesses are systematically lower than the experimental values in the case of a low oxygen concentration when the iron diffusion only occurs via interstitials in the oxide scale. Consequently, the estimation of the iron diffusion coefficient, when diffusion occurs via interstitials, is not reliable. To have a better estimation of this iron diffusion coefficient in the Fe‐Cr spinel, when diffusion occurs via interstitials, a fit is done using experimental data coming from the European DEMETRA project. Although this evaluation is only based on a fit on the experimental data, it permits to estimate the oxide layer growth kinetics in case of the formation of the described duplex oxide layer, for each oxygen concentration (leading to a vacancy and/or an interstitial diffusion), each temperature between 450 and 620 °C and each hydrodynamic flow. This model shows that the hydrodynamic flow affects the corrosion rate only by the removal of the upper magnetite layer leading to an increase of the oxygen concentration at the spinel/magnetite interface. The oxidation mechanism is thus neither changed by the Pb‐Bi flow nor by the oxygen concentration. However, the oxygen concentration modifies the iron diffusion process in the oxide lattice.
Corrosion performance and mechanical properties of joined automotive materials
Authors: LeBozec N. , LeGac A. , Thierry D.
Published: January 2011

The automotive industry envisions that an optimized vehicle in terms of performance and cost can be achieved only by using different materials at different vehicle locations in order to utilize the functionality of the different materials to a full extent. Currently, steel and aluminum are the most important construction materials for the mass production of automotive structure. However, other materials such as magnesium alloys and stainless steel are also used. The use of dissymmetric assemblies of materials in the automotive industry has also led to the development of joining technologies other than spot welding and arc welding such as clinching, adhesive bonding, laser welding, and MIG brazing. However, and despite the development of these new joining technologies, there are still important gaps of knowledge with regards to the corrosion performance of different joint populations using dissymmetric and symmetric materials. Materials commonly used in the automotive industry including steel and aluminum‐based susbtrates were assembled with different combinations using various joining techniques in order to evaluate their corrosion performance as well their mechanical properties after cyclic accelerated corrosion tests. The results indicated a relationship between the corrosion inside the confined joint and the decrease of the mechanical properties of the assemblies.
MR intensity measurements of nondenervated muscle in patients following severe forearm trauma
Authors: Viddeleer A.R. , Sijens P.E. , van Ooijen P.M.A. , Kuypers P.D.L. , Hovius S.E.R. , Oudkerk M.
Published: January 2011

Fluid increases resulting in higher MRI signal intensities in T2‐weighted and short tau inversion recovery (STIR) sequences can be used to diagnose nerve injury. By comparing the signal intensities over time, MRI may become a new method for monitoring the healing process. Muscle edema is assessed by comparing the signal intensity of affected muscle with that of nonaffected muscle. However, in severe forearm trauma, the signal of nondenervated muscle may also be increased by wound edema, thus masking the effect of denervation. Hence, the purpose of this study was to investigate the influence of wound edema on muscle signal intensity in 29 consecutive patients examined on a 1.5‐T MRI scanner at 1, 3, 6, 9 and 12 months after severe forearm trauma. The long‐term course of wound edema and the influence of wound distance were thus investigated using a standardized imaging, calibration and post‐processing protocol. The signal intensities of nondenervated intrinsic hand muscles were measured in the affected and contralateral sides. Muscle signal intensities were increased on the trauma side at 1 and 3 months (18% and 7.4%, respectively; p < 0.001) and normalized thereafter. In the contralateral hand, no significant signal changes were seen. No relationship was found between wound distance and the severity of wound edema. This study shows that wound edema influences muscle signal intensity comparisons in patients with forearm trauma. When comparing denervated muscle with nondenervated muscle, an additional scan of the contralateral side is indicated during the first 6 months after trauma to assess the extent of wound edema. After 6 months, the ipsilateral side can be used for muscle signal intensity comparisons. Copyright © 2011 John Wiley & Sons, Ltd.
31P and 13C solid‐state NMR spectroscopy to study collagen synthesis and biomineralization in polymer‐based bone implants
Authors: Weber Franziska , Böhme Julia , Scheidt Holger A. , Gründer Wilfried , Rammelt Stefan , Hacker Michael , Schulz‐Siegmund Michaela , Huster Daniel
Published: January 2011

A combination of solid‐state NMR spectroscopy and MRI was used to evaluate the formation of extracellular matrix in poly(D,L‐lactide‐co‐glycolide) (PLGA) bone implants. Porous PLGA scaffolds were implanted into rat tibiae and analysed after 2, 4 or 8 weeks. MRI clearly delineated the implants within the cancellous bone. Differences in the trabecular structure of the implanted material and native bone were demonstrated. In addition, implants were analyzed by solid‐state NMR spectroscopy under magic angle spinning. 13C NMR spectra showed the unambiguous signature of collagen formed in the scaffolds, but also the characteristic signals of the PLGA matrix, indicating that resorption was not complete after 8 weeks. Furthermore, 31P NMR spectroscopy detected the inorganic component of the matrix, which is composed of bioapatite. 31P NMR spectra were quantified and this analysis revealed that the amount of inorganic extracellular matrix formed de novo was significantly lower than in native bone. This demonstrates that solid‐state NMR spectroscopy, in particular in combination with MRI, can provide useful information on the composition and structure of the extracellular matrix, and serve as a tool to evaluate the quality of tissue engineering strategies. Copyright © 2011 John Wiley & Sons, Ltd.
Structural inhomogeneities in polycrystalline silicon on glass solar cells and their effects on device characteristics
Authors: Wong J. , Huang J. L. , Varlamov S. , Green M. A. , Evans R. , Keevers M. , Egan R. J.
Published: January 2011

The effects of electrostatic fluctuations due to charged extended defects and strain‐induced bandgap fluctuations are examined in polycrystalline silicon on glass solar cells. The analysis is based on models previously applied to Cu(In,Ga)Se2 solar cells, but with a new interpretation of the local ideality factor associated with electrostatic fluctuations. It is shown that electrostatic fluctuations become influential to the cell voltage properties as the absorber dopant concentration falls below a certain threshold (a few 1015 cm−3), and the degradations to the open circuit voltage and fill factor are expected to increase with further lowering of dopant density. It is equally plausible that the electrostatic fluctuations originate from charged dislocations or grain boundaries. Bandgap fluctuations on the other hand can be detrimental to the open circuit voltage of cells of any absorber dopant density. However, this voltage degrading effect is seen only in the cells deposited by electron‐beam evaporation, and not amongst those made by plasma enhanced chemical vapour deposition. Copyright © 2011 John Wiley & Sons, Ltd.
Enhancing the Mechanical Properties of Superhydrophobic Atmospheric Pressure Plasma Deposited Siloxane Coatings
Authors: Nwankire Charles E. , Favaro Gregory , Duong Quynh‐Huong , Dowling Denis P.
Published: January 2011

Surfaces with water contact angles above 150° are regarded as superhydrophobic. In this study the use of atmospheric pressure plasma jet system called PlasmaStreamTM to deposit superhydrophobic coatings is investigated. The coatings were deposited from the following liquid precursors: hexamethyldisiloxane (HMDSO), tetramethyl cyclotetrasiloxane (Tomcats) and a mixture of Tomcats and fluorosiloxane. The objective of the study is to investigate how precursor type and deposition conditions, influences the morphology and mechanical performance of the deposited superhydrophobic coatings. Optical profilometry, AFM, SEM, Ellipsometry, XPS, Water contact angle and FTIR techniques were used to evaluate the surface roughness, morphology, thickness and chemical functionality of the deposited coatings. The mechanical properties were evaluated using the Nano Tribometer, Nano Scratch, Ultra Nanoindentation and ultrasonic abrasion tests. Superhydrophobic coatings deposited from a precursor mixture of Tomcats and fluorosiloxane yielded a substantial enhancement in coating adhesion and mechanical durability compared to the superhydrophobic coatings obtained with either Tomcats or HMDSO precursors alone.

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Chromosome 8q24 variants are associated with prostate cancer risk in a high risk population of African ancestry
Authors: Okobia Michael N. , Zmuda Joseph M. , Ferrell Robert E. , Patrick Alan L. , Bunker Clareann H.
Published: January 2011

BACKGROUND

Earlier studies on the role of germline variations in the disproportionate higher burden of prostate cancer in men of African ancestry have been largely unrewarding. However, the successful replication of recent genome‐wide association findings implicating some regions of chromosome 8q24 in the disparate prostate cancer susceptibility in men of European and African ancestry have been encouraging. This case–control study was designed to evaluate the association between germline variations in chromosome 8q24 and prostate cancer risk in Afro‐Caribbean Tobago men, a population of predominantly West African ancestry.

METHODS

High molecular weight genomic DNA was isolated from blood clots using Qiagen kits. Genotyping was performed on genomic DNA using a pre‐designed TaqMan SNP assay according to the manufacture's protocol on a 7900HT Fast Real‐Time PCR system (Applied Biosystems, Foster City, CA).

RESULTS

SNP rs16901979 in region 2 was associated with significantly increased risk of prostate cancer (OR = 1.41, 95% confidence interval [CI] 1.02–1.95, P = 0.04) with the risk stronger in men with early‐onset prostate cancer (OR = 2.37, 95% CI 1.40–3.99, P = 0.001). There was a tendency towards significantly increased risk for SNPs rs1447295 and rs6983267 in men with early‐onset prostate cancer.

CONCLUSIONS

The replication of the association of chromosome 8q24 variants with increased prostate cancer risk in Tobago men and the higher frequency of the risk alleles in controls in populations of African ancestry further strengthens the possible role of this genomic region in the disproportionate higher burden of prostate cancer in men of African ancestry. Prostate 71:1054–1063, 2011. © 2011 Wiley‐Liss, Inc.
Reduced glycosylation of α‐dystroglycans on carcinoma cells contributes to formation of highly infiltrative histological patterns in prostate cancer
Authors: Shimojo Hisashi , Kobayashi Motohiro , Kamigaito Takayuki , Shimojo Yasuyo , Fukuda Minoru , Nakayama Jun
Published: January 2011

BACKGROUND

α‐Dystroglycan (DG) carries glycan chains that bind to laminin and thus function in homeostasis of not only skeletal muscle but also of various epithelial cells. Loss of glycosylation has been suggested to play important roles in tumor development, particularly in detachment and migration of carcinoma cells. We previously reported that glycosylation of α‐DG, but not levels of α‐DG core protein itself, is reduced in prostate carcinoma. In this study, we investigate the association between reduction of laminin‐binding glycans on α‐DG and the degree of tumor cell differentiation and/or infiltrative properties, as assessed by the Gleason grading system.

METHODS

Immunohistochemical analysis of 146 biopsy specimens of prostate adenocarcinoma with various Gleason scores was carried out employing IIH6 and 6C1 antibodies, which recognize laminin‐binding glycans on α‐DG and α‐DG core proteins, respectively. Double immunofluorescence staining was performed to evaluate colocalization of α‐DG and laminin, and to determine which types of epithelial cells express laminin‐binding glycans on α‐DG.

RESULTS

Reduction of α‐DG glycosylation, rather than loss of α‐DG core protein, was correlated with higher Gleason patterns. Reduction was most conspicuous at the interface between carcinoma cells and the basement membrane. In addition, in non‐neoplastic prostate glands, laminin‐binding glycans were expressed predominantly on the basolateral surface of basal cells.

CONCLUSIONS

Reduced expression of laminin‐binding glycans on α‐DG may contribute to formation of highly infiltrative behavior of prostate carcinoma cells. Substantial reduction of laminin‐binding glycans in carcinoma tissue could be partly ascribed to disappearance of pre‐existing basal cells. Prostate 71:1151–1157, 2011. © 2011 Wiley‐Liss, Inc.
Reactivation of embryonic nodal signaling is associated with tumor progression and promotes the growth of prostate cancer cells
Authors: Lawrence Mitchell G. , Margaryan Naira V. , Loessner Daniela , Collins Angus , Kerr Kris M. , Turner Megan , Seftor Elisabeth A. , Stephens Carson R. , Lai John ,   APC BioResource, Postovit Lynne‐Marie , Clements Judith A. , Hendrix Mary J.C.
Published: January 2011

BACKGROUND

Nodal is a member of the transforming growth factor β (TGFβ) superfamily that directs embryonic patterning and promotes the plasticity and tumorigenicity of tumor cells, but its role in the prostate is unknown. The goal of this study was to characterize the expression and function of Nodal in prostate cancer and determine whether, like other TGFβ ligands, it modulates androgen receptor (AR) activity.

METHODS

Nodal expression was investigated using immunohistochemistry of tissue microarrays and Western blots of prostate cell lines. The functional role of Nodal was examined using Matrigel and soft agar growth assays. Cross‐talk between Nodal and AR signaling was assessed with luciferase reporter assays and expression of endogenous androgen regulated genes.

RESULTS

Significantly increased Nodal expression was observed in cancer compared with benign prostate specimens. Nodal was only expressed by DU145 and PC3 cells. All cell lines expressed Nodal's co‐receptor, Cripto‐1, but lacked Lefty, a critical negative regulator of Nodal signaling. Recombinant human Nodal triggered downstream Smad2 phosphorylation in DU145 and LNCaP cells, and stable transfection of pre‐pro‐Nodal enhanced the growth of LNCaP cells in Matrigel and soft agar. Finally, Nodal attenuated AR signaling, reducing the activity of a PSA promoter construct in luciferase assays and down‐regulating the endogenous expression of androgen regulated genes.

CONCLUSIONS

An aberrant Nodal signaling pathway is re‐expressed and functionally active in prostate cancer cells. Prostate 71:1198–1209, 2011. © 2011 Wiley‐Liss, Inc.
Loss of EGFR induced autophagy sensitizes hormone refractory prostate cancer cells to adriamycin
Authors: Xu Shuping , Weihua Zhang
Published: January 2011

BACKGROUND

The epidermal growth factor receptor (EGFR), a receptor tyrosine kinase, is over‐expressed in advanced prostate cancer but tyrosine kinase inhibitors are not clinically effective in the treatment of prostate cancer. Recently it was found that EGFR in cancer cells has a kinase‐independent pro‐survival function, preventing cells from undergoing autophagy. In the present study we investigated whether the anti‐autophagic function of EGFR may contribute to resistance of hormone‐refractory prostate cancer cells to chemotherapeutic‐induced apoptosis.

METHODS

We first characterized the autophagic phenotype induced by knocking down EGFR in hormone refractory prostate cancer cells (PC‐3MM2 and DU‐145), then we tested whether loss of EGFR‐induced autophagy could sensitize cancer cells to adriamycin.

RESULTS

Using continuous live cell imaging techniques, we observed that knocking down EGFR lead to typical autophagic morphological/molecular changes, cell shrinkage without detachment, aggregation of microtubule‐associated protein 1 light chain 3 (LC3) protein and absence of activation of apoptotic caspases 3/7. Loss of EGFR also increased the activity of calpain, which is pro‐apoptotic. Knocking down EGFR, but not inhibiting its tyrosine kinase activity, significantly sensitized cells to adriamycin‐induced apoptosis. Adriamycin‐induced apoptosis could be inhibited by increased extracellular glucose level, suggesting intracellular glucose deficiency is a key mediator of the sensitization. The loss of EGFR induced autophagy and sensitization to adriamycin were also reproduced by using another hormone refractory prostate cancer cell line, Du145.

CONCLUSION

Taken together, these data suggest that decreasing the expression level of EGFR protein, rather than inhibiting its tyrosine kinase activity, may enhance the efficiency of EGFR targeted therapy for prostate cancer. Prostate 71:1216–1224, 2011. Published 2011 Wiley‐Liss, Inc.
Effect of indium mole fraction on infrared light emitting diode (LED) device performance
Authors: Das Naresh C.
Published: January 2011

We report on the design and fabrication of interband cascade light emitting diode (LED) device with InAs/Ga1−xInxSb/InAs quantum well (QW) active region. We have varied indium (In) contents in the QW region between 18 and 30% from x = 0.18 to 0.3 and found that light emission power increases with decrease of In percentage value. We observed a 200% increase in light emission power by decreasing the In content from 30 to 18%. By cooling the LED device, we observed a higher increase in light output power for higher In content devices compared to that of lower In content devices.
Electrical and optical study of phase transitions in thermally evaporated GeTe films
Authors: Kumar P. , Thangaraj R. , Sathiaraj T. S.
Published: January 2011

Amorphous to crystalline phase transformations in thermally evaporated GeTe films have been analyzed by using the resistivity–temperature curves and optical spectroscopic techniques. The phase‐transition temperature increases slightly with annealing temperature, while a large change in the sheet resistance and appreciable decrease in the dc activation energy has been observed due to this transformation. The small value of sheet resistance for the crystalline films as compared to the amorphous ones above the transition temperature reveal the influence of the polarization near the metal/semiconductor interface forming the blocking layer at the interface toward the semiconductor side. The optical contrast value decreases with the decrease in wavelength due to the transitions from the deep levels below the valence band edge. The imaginary parts of dielectric function (ε2) have been calculated from the reflectivity data using the Kramers–Kronig transformations and exhibit its strong dependence on the annealing temperature. The optical gap and tailing parameter have also been studied with annealing temperature. These results have been explained on the basis of the structural relaxation or the change in the local structure due to amorphous–crystalline transformation in the GeTe film due to thermal annealing.
Dopant diffusivity and solubility in nickel silicides
Authors: Blum Ivan , Portavoce Alain , Hoummada Khalid , Tellouche Gamra , Chow Lee , Mangelinck Dominique , Carron Véronique
Published: January 2011

Boron and Arsenic diffusion in implanted Ni2Si and NiSi layers has been studied using secondary ion mass spectrometry. These measurements show that As should not diffuse in the silicides at the temperatures used for silicidation. In contrast significant B diffusion is observed in both silicides at temperatures as low as 400°C. It is also observed that both dopants have higher solubilities in Ni2Si than in NiSi. B and As solubilities below 1.1020 at.cm‐3 are measured in NiSi (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐rate deposition of nano‐crystalline silicon thin films on plastics
Authors: Marins E. , Guduru V. , Ribeiro M. , Cerqueira F. , Bouattour A. , Alpuim P.
Published: January 2011

Nanocrystalline silicon (nc‐Si:H) is commonly used in the bottom cell of tandem solar cells. With an indirect bandgap, nc‐Si:H requires thicker (∼1 µm) films for efficient light harvesting than amorphous Si (a‐Si:H) does. Therefore, thin‐film high deposition rates are crucial for further cost reduction of highly efficient a–Si:H based photovoltaic technology. Plastic substrates allow for further cost reduction by enabling roll‐to‐roll inline deposition. In this work, high nc‐Si:H deposition rates on plastic were achieved at low substrate temperature (150 °C) by standard Radio‐frequency (13.56 MHz) Plasma Enhanced Chemical Vapor Deposition. Focus was on the influence of deposition pressure, inter‐electrode distance (1.2 cm) and high power coupled to the plasma, on the hydrogen‐to‐silane dilution ratios (HD) necessary to achieve the amorphous‐to‐nanocrystalline phase transition and on the resulting film deposition rate. For each pressure and rf‐power, there is a value of HD for which the films start to exhibit a certain amount of crystalline fraction. For constant rf‐power, this value increases with pressure. Within the parameter range studied the deposition rate was highest (0.38 nm/s) for nc‐Si:H films deposited at 6 Torr, 700 mW/cm2 using HD of 98.5%. Decreasing the pressure to 3 Torr (1.5 Torr) and rf‐power to 350 mW/cm2 using HD – 98.5% deposition rate is 0.12 nm/s (0.076 nm/s). Raman crystalline fraction of these films is 72, 62 and 53% for the 6, 3 and 1.5 Torr films, respectively (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In situ aerosol measurements taken during the 2007 COPS field campaign at the Hornisgrinde ground site
Authors: Jones H. M. , Crosier J. , Russell A. , Flynn M. J. , Irwin M. , Choularton T. W. , Coe H. , McFiggans G.
Published: January 2011

The Convective and Orographically‐induced Precipitation Study (COPS) campaign was conducted during the summer of 2007. A suite of instruments housed at the top of the Hornisgrinde Mountain (1156 m) in the Black Forest region of south‐west Germany provided datasets that allow an investigation into the physical, chemical and hygroscopic properties of the aerosol particles sampled during COPS. Organic mass loadings were found to dominate the aerosol composition for the majority of the project, exceeding 8 µg m−3 during a period of high pressure, high temperature, and low wind speed. The ratio of organic:sulphate sub‐micron mass concentration exceeds 10:1 during the same time period. Back trajectories show air from this time‐frame passing slowly over the local forest and not passing over any local anthropogenic sources. Occasional peaks in nitrate mass loadings were associated with changes in the typical wind direction from south‐westerly to north‐westerly where air had passed over the Stuttgart region. Size distribution data shows a dominant accumulation‐mode when the measurement site was free from precipitation events. A sharp increase in ultrafine particle number concentration was seen during most days commencing around noon. The apparent growth of these particles is associated with an increase in organic mass loading, suggesting condensational growth. For the most part, with the exception of the high pressure period, the aerosol properties recorded during COPS were comparable to previous studies of continental aerosol properties. Copyright © 2011 Royal Meteorological Society
The reaction mechanism of the gas‐phase thermal decomposition kinetics of neopentyl halides: A DFT study
Authors: Mora José R. , Márquez Edgar , Lezama Jesus , Córdova Tania , Chuchani Gabriel
Published: January 2011

The kinetics and mechanisms of the gas‐phase elimination reactions of neopentyl chloride and neopentyl bromide have been studied by means of electronic structure calculations using density functional methods: B3LYP/6‐31G(d,p), B3LYP/ 6‐31++G(d,p), MPW1PW91/6‐31G(d,p), MPW1PW91/6‐31++G(d,p), PBEPBE/6‐31G(d,p), PBEPBE /6‐31++G(d,p). The reaction channels that account in products formation have a common first step involving a Wagner‐Meerwein rearrangement. The migration of the halide from the terminal carbon to the more substituted carbon is followed by beta‐elimination of HCl or HBr to give two olefins: the Sayzeff and Hoffmann products. Theoretical calculations demonstrated that these eliminations proceed through concerted asynchronous process. The transition state (TS) located for the rate‐determining step shows the halide detached and bridging between the terminal carbon and the quaternary carbon, while the methyl group is also migrating in a concerted fashion. The TS is described as an intimate ion‐pair with a large negative charge at the halide atom. The concerted migration of methyl group provides stabilization of the TS by delocalizing the electron density between the terminal carbon and the quaternary carbon. The B3LYP/6‐31++G(d,p) allows to obtain reasonable energies and enthalpies of activation. The nature of these reactions is examined in terms of geometrical parameters, electron distribution, and bond order analysis. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Strengthening biostatistics resources in sub‐Saharan Africa: Research collaborations through U.S. partnerships
Authors: Gezmu Misrak , DeGruttola Victor , Dixon Dennis , Essex Max , Halloran Elizabeth , Hogan Joseph , Grobler Anneke , Kim Soyeon , McDermott Jeanne , McKaig Rosemary , Neaton James D.
Published: January 2011

On September 30, 2009, the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH) conducted a workshop on strengthening biostatistics resources in sub‐Saharan Africa (SSA). An increase in global spending on health research over the last decade has boosted funds available to conduct biomedical research in low‐ to mid‐income countries. The HIV/AIDS pandemic, the re‐emergence of malaria and tuberculosis, and other emerging infectious agents are major driving forces behind the increase in biomedical research and clinical care programs (clinical trials, observational studies and, other public health programs) in SSA (Exp. Biol. Med. 2008; 233:277–285). In addition, the increased engagement of the United States (U.S.) government through the Global Health Initiative, which expands the traditional focus beyond infectious diseases to other causes of poor health and to the recognition of need the to strengthen health systems for a sustainable response, only increases the need for in‐depth in‐country expertise in all aspects of biomedical research (White House Press Release, 2009).

In this workshop, researchers both from the U.S. and SSA were invited to discuss their collaborative work, to discuss ways in which biostatistical activities are carried out within their research projects, and to identify both general and specific needs for capacity building in biostatistics. Capacity building discussions highlighted the critical need to increase the number of well‐trained in‐country biostatisticians, both to participate in ongoing studies and to contribute to an infrastructure that can produce the next generation of biostatistical researchers. Copyright © 2011 John Wiley & Sons, Ltd.
Test non‐inferiority (and equivalence) based on the odds ratio under a simple crossover trial
Authors: Lui Kung‐Jong , Chang Kuang‐Chao
Published: January 2011

For testing the non‐inferiority (or equivalence) of a generic drug to a standard drug, the odds ratio (OR) of patient response rates has been recommended to measure the relative treatment efficacy. On the basis of a random effects logistic regression model, we develop asymptotic test procedures for testing non‐inferiority and equivalence with respect to the OR of patient response rates under a simple crossover design. We further derive exact test procedures, which are especially useful for the situations in which the number of patients in a crossover trial is small. We address sample size calculation for testing non‐inferiority and equivalence based on the asymptotic test procedures proposed here. We also discuss estimation of the OR of patient response rates for both the treatment and period effects. Finally, we include two examples, one comparing two solution aerosols in treating asthma, and the other one studying two inhalation devices for asthmatics, to illustrate the use of the proposed test procedures and estimators. Copyright © 2011 John Wiley & Sons, Ltd.
A formal framework to test soft and hard deadlines in timed systems
Authors: Merayo Mercedes G. , Núñez Manuel , Rodríguez Ismael
Published: January 2011

This paper introduces a formal framework to specify and test systems presenting both soft and hard deadlines. While hard deadlines must always be met on time, soft deadlines can be sometimes met in a different time, usually greater, from the specified one. It is this characteristic (to formally definetextitsometimes) that produces several reasonable alternatives to define appropriate implementation relations, that is, relations to decide whether an implementation is correct with respect to a specification. In addition to introducing these relations, the paper also presents a formal testing framework to test implementations and provides an algorithm to derive sound and complete test suites with respect to the implementation relations previously defined. That is, an implementation conforms to a specification if and only if the implementation successfully passes all the tests belonging to the suite derived from the specification. Copyright © 2011 John Wiley & Sons, Ltd.
A study of probabilistic voltage profile analysis method in island power system
Authors: Trivedi Indrajit N. , Tsuji Takao , Oyama Tsutomu , Hashiguchi Takuhei , Goda Tadahiro , Ueda Yasunori
Published: January 2011

For island power systems, generally diesel engine generators are being used for supplying power. In recent years, much attention is being paid to renewable energy sources to improve the CO2 emission problem which is a serious issue worldwide. Although the utilization of renewable energy is effective, it poses problems because of the fact that the voltage profile changes due to the reverse power flow. Conventionally, the deterministic load model is used for power flow calculations. However, in a small power system such as the island power system, the deterministic model is not effective as the ‘law of great numbers’ is not applicable. Therefore, in this study, we have developed a new probabilistic approach to analyze the voltage profile of a small power network using the binomial distribution model. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Feature subset selection: a correlation‐based SVM filter approach
Authors: Li Boyang , Wang Qiangwei , Hu Jinglu
Published: January 2011

The central criterion of feature selection is that good feature sets contain features that are highly correlated with the output, yet uncorrelated with each other. Based on this criterion, we address the problem of feature selection through correlation‐based feature clustering and support vector machine (SVM) based feature ranking. Correlation‐based clustering is proposed to group features into some clusters based on the correlation between two features. As a result, a feature is highly correlated to any other feature in the same cluster but uncorrelated to the features in other clusters. From each cluster, we select a feature as the delegate based on its influence quantities on the output. The influence quantities are measured by the feature sensitivity in the SVM. The proposed approach can identify relevant features and eliminate redundancy among them effectively. The effectiveness of the proposed approach is demonstrated through comparisons with other methods using real‐world data with different dimensions. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Multiphysics analysis for micro electromechanical systems based on electrical circuit simulator
Authors: Mita Makoto , Maruyama Satoshi , Yi Yuheon , Takahashi Kazuhiro , Fujita Hiroyuki , Toshiyoshi Hiroshi
Published: January 2011

We report a newly developed equivalent electrical circuit for microelectromechanical systems (MEMS) based on a circuit simulator Qucs (Quite Universal Circuit Simulator). An analog computing solver for the equation of motion (EOM) has been interpreted to an electrical equivalent circuit by using an electrical capacitor as an ideal mathematic integrator. Viscoelastic suspension and electrostatic parallel‐plate actuator are modeled as equivalent subcircuits that can be cosolved with the EOM module. Those subcircuit models are used as building blocks to numerically simulate the behavior of various types of MEMS actuators. Thanks to the well‐prepared simulation toolbox of Qucs, multiphysics analysis of micromechanical and electrical quantities has become straightforward on a single platform. Equivalent circuit models for coupled oscillator and parallel‐plate electrostatic actuator (including mechanical contact after electrostatic pull‐in) are presented as a verification program to examine the simulation accuracy. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Maternal attitudes towards prenatal diagnosis of idiopathic clubfoot
Authors: Radler C. , Myers A. K. , Burghardt R. D. , Arrabal P. P. , Herzenberg J. E. , Grill F.
Published: January 2011

Objectives

To examine maternal attitudes towards prenatal diagnosis of idiopathic clubfoot and to determine the incidence of false‐negative ultrasound examinations.

Methods

Surveys were mailed to mothers of patients with clubfoot born between 2000 and 2007 who were treated at either Sinai Hospital of Baltimore or Orthopaedic Hospital Speising. Exclusion criteria were underlying syndrome, genetic abnormality and multiple pregnancy. The survey asked the mother whether she had had any ultrasound examinations before her child was born, whether any of these had shown clubfoot, and whether she would have preferred to find out about her child's clubfoot before birth or after birth.

Results

Mothers completed 220 (USA, 105 surveys; Austria, 115 surveys) of 401 mailed surveys. The prenatal detection rate was 60% in the USA compared with 25% in Austria (P = 0.001). Overall, 74% of mothers indicated a preference for prenatal diagnosis and 24% indicated a preference for postnatal diagnosis of the condition. Of 92 patients diagnosed prenatally, 96% of mothers indicated a preference for a prenatal diagnosis. Of 128 patients diagnosed postnatally, 58% of mothers indicated a preference for prenatal diagnosis, 38% for postnatal diagnosis and 4% were undecided.

Conclusions

The diagnosis of clubfoot is still often missed during routine ultrasound examination. When a prenatal diagnosis is made, most mothers appreciate having this information. However, when prenatal diagnosis is missed, a significant proportion of mothers seem to accept the false‐negative diagnosis retrospectively. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Fetal echocardiography at 11–13 weeks by transabdominal high‐frequency ultrasound
Authors: Persico N. , Moratalla J. , Lombardi C. M. , Zidere V. , Allan L. , Nicolaides K. H.
Published: January 2011

Objectives

To assess the accuracy of fetal echocardiography at 11–13 weeks performed by well‐trained obstetricians using a high‐frequency linear ultrasound transducer.

Methods

Fetal echocardiography was performed by obstetricians immediately before chorionic villus sampling for fetal karyotyping at 11–13 weeks. Digital videoclips of the examination stored by the obstetrician were reviewed offline by a specialist fetal cardiologist.

Results

The obstetrician suspected 95 (95%) of the 100 cardiac defects identified by the fetal cardiologist and made the correct diagnosis in 84 (84%) of these cases. In 54 fetuses, the defect was classified as major and in 46 it was minor. In 767 (86.6%) cases, the heart was normal and in 19 (2.1%) the views were inadequate for assessment of normality or abnormality. A subsequent second‐trimester scan in the normal group identified major cardiac defects in four cases. Therefore, the first‐trimester scan by the obstetricians and cardiologists identified 54 (93.1%) of the 58 major cardiac defects.

Conclusions

A well‐trained obstetrician using high‐resolution ultrasound equipment can assess the fetal heart at 11–13 weeks with a high degree of accuracy. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Vakuumisolierung in der Fernwärme
Authors: Hauck Günter
Published: January 2011

Die Vakuumisolierung bietet ein Höchstmaß an Betriebssicherheit und Wirtschaftlichkeit in der Fernwärmeversorgung. Zuverlässige Vakuumkomponenten haben zu den Fortschritten in der Fernwärmetechnik entscheidend beigetragen.
Neue massenspektrometrische Methoden in der anorganischen Spurenanalytik
Authors: Greb Ulrich
Published: January 2011

In nur fünf Jahren hat die Spurenanalyse mit ICP‐MS eine weite Verbreitung in analytischen Labors gefunden. Die Gründe dafür sind in der einfachen Handhabung, der Flexibilität der Anwendung und der Nachweisstärke bis unter 1 ppt zu suchen. Hochauflösende GD‐MS hat sich einen festen Platz in der Ultraspurenanalyse von hochreinen Metallen erobert, eine weitere Verbreitung in der Spurenanalytik hat aber erst kürzlich durch die Einführung von GD‐MS mit einem Quadrupolanalysator begonnen. Beide Methoden ergänzen sich vorzüglich und werden in der Kombination einen festen Platz im analytischen Labor erobern.
Die Entwicklung der Gasreibungspumpe von Gaede über Holweck und Siegbahn bis zu Pfleiderer und Becker
Authors: Reich Günter
Published: January 2011

Gasreibungspumpen haben in den letzten 30 Jahren eine immer größere Bedeutung in der Vakuumtechnik erlangt. In diesem Beitrag wird die Entstehung dieses Pumpprinzips und die Entwicklung der verschiedenen Versionen dokumentiert.
Adaptation and risk management
Authors: Jones Roger N. , Preston Benjamin L.
Published: January 2011

Adaptation assessment methods are compatible with the international risk management standard ISO:31000. Risk management approaches are increasingly being recommended for adaptation assessments at both national and local levels. Two orientations to assessments can commonly be identified: top‐down and bottom‐up, and prescriptive and diagnostic. Combinations of these orientations favor different types of assessments. The choice of orientation can be related to uncertainties in prediction and taking action, in the type of adaptation and in the degree of system stress. Adopting multiple viewpoints is to be encouraged, especially in complex situations. The bulk of current guidance material is consistent with top‐down and predictive approaches, thus is most suitable for risk scoping and identification. A broad range of material from within and beyond the climate change literature can be used to select methods to be used in assessing and implementing adaptation. The framing of risk, correct formulation of the questions being investigated and assessment methodology are critical aspects of the scoping phase. Only when these issues have been addressed should be issue of specific methods and tools be addressed. The reorientation of adaptation from an assessment focused solely on anthropogenic climate change to broader issues of vulnerability/resilience, sustainable development and disaster risk, especially through a risk management framework, can draw from existing policy and management understanding in communities, professions and agencies, incorporating existing agendas, knowledge, risks, and issues they already face. WIREs Clim Change 2011 2 296–308 DOI: 10.1002/wcc.97

This article is categorized under:

Vulnerability and Adaptation to Climate Change > Values‐Based Approach to Vulnerability and Adaptation
Synthesis and Reactivity of a Dilithiated Molybdenum Half‐Sandwich Complex
Authors: Braunschweig Holger , Dörfler Rainer , Gruß Katrin , Radacki Krzysztof
Published: January 2011

The dimetallated half‐sandwich complex Li[(η5‐C5H4Li)(CO)3Mo] was prepared by double deprotonation of the corresponding hydride complex [(η5‐C5H5)H(CO)3Mo] with tert‐butyllithium. The subsequent treatment with Me3SnCl gave access to the bis(stannyl) complex [(η5‐C5H4SnMe3)(SnMe3)(CO)3Mo]. Additionally, reactions of this compound with selected chlorostannanes yielded several different bis(chlorostannyl) half‐sandwich complexes, which were fully characterized by multinuclear NMR spectroscopy and X‐ray crystallography.
N‐Methyl‐anilinoborane: Monomer, Dimers, Molecular Structure, and Rearrangement into μ‐(N‐Methyl‐anilino)diborane(6). A Convenient Route to μ‐(Amino)diboranes(6)
Authors: Wrackmeyer Bernd , Molla Elias , Thoma Peter , Klimkina Elena V. , Tok Oleg L. , Bauer Tobias , Kempe Rhett
Published: January 2011

N‐Methyl‐anilinoborane exists as a dimer in the solid state, shown by X‐ray structural analysis, whereas in solution, a monomer–dimer equilibrium is present (1H, 11B and 13C NMR spectroscopy). The phenyl groups are in trans positions in the crystalline dimer. In solution, both possible isomers of the dimer exist in a trans/cis ratio of 3:2, in agreement with the energies for calculated optimized geometries [B3LYP/6‐311+G(d,p) level of theory]. In solution, the monomer is rather reactive and disproportionates completely after several days to give a 1:1 mixture of bis(N‐methyl‐anilino)borane and μ‐(N‐methyl‐anilino)diborane(6). This observation led to a convenient high yield synthesis of μ‐(amino)diborane(6) derivatives, starting from bis(amino)boranes and borane/THF.
Analysis of synaptic proteins in the cerebrospinal fluid as a new tool in the study of inborn errors of neurotransmission
Authors: Duarte Sofia T. , Ortez Carlos , Pérez Ana , Artuch Rafael , García‐Cazorla Angels
Published: January 2011

In a few rare diseases, specialised studies in cerebrospinal fluid (CSF) are required to identify the underlying metabolic disorder. We aimed to explore the possibility of detecting key synaptic proteins in the CSF, in particular dopaminergic and gabaergic, as new procedures that could be useful for both pathophysiological and diagnostic purposes in investigation of inherited disorders of neurotransmission. Dopamine receptor type 2 (D2R), dopamine transporter (DAT) and vesicular monoamine transporter type 2 (VMAT2) were analysed in CSF samples from 30 healthy controls (11 days to 17 years) by western blot analysis. Because VMAT2 was the only protein with intracellular localisation, and in order to compare results, GABA vesicular transporter, which is another intracellular protein, was also studied. Spearman's correlation and Student's t tests were applied to compare optical density signals between different proteins. All these synaptic proteins could be easily detected and quantified in the CSF. DAT, D2R and GABA VT expression decrease with age, particularly in the first months of life, reflecting the expected intense synaptic activity and neuronal circuitry formation. A statistically significant relationship was found between D2R and DAT expression, reinforcing the previous evidence of DAT regulation by D2R. To our knowledge, there are no previous studies on human CSF reporting a reliable analysis of these proteins. These kinds of studies could help elucidate new causes of disturbed dopaminergic and gabaergic transmission as well as understanding different responses to L‐dopa in inherited disorders affecting dopamine metabolism. Moreover, this approach to synaptic activity in vivo can be extended to different groups of proteins and diseases.
Neonatal cholestasis: an uncommon presentation of hyperargininemia
Authors: Gomes Martins Esmeralda , Santos Silva Ermelinda , Vilarinho Silvia , Saudubray Jean Marie , Vilarinho Laura
Published: January 2011

Hyperargininemia is a rare inborn error of metabolism due to arginase deficiency, which is inherited in an autossomal recessive manner. Arginase is the final enzyme of the urea cycle and catalyzes the conversion of arginine to urea and ornithine. This condition typically presents in early childhood (between 2 and 4 years of age) with developmental delay associated with progressive spastic paraparesis. Neonatal presentation is very uncommon with a poorly described outcome. Here, we discuss two cases of neonatal cholestasis as initial clinical presentation of hyperargininemia. In case 1, diagnosis was established at 2 months of age upon investigation of the etiology of cholestatic injury pattern and hepatosplenomegaly, and treatment was then initiated at when the patient was 3 months old. Unfortunately, the patient had progressive biliary cirrhosis to end‐stage liver disease complicated with portal hypertension for which she underwent successful orthotopic liver transplant at 7 years of age. In case 2, hyperargininemia was identified through newborn screening and treatment was started when patient was 21 days old. Cholestasis was only identified in the patient's further evaluation and it resolved 2 weeks into treatment. The patient is currently 18 months old and her development and neurological examination remain unremarkable. Neonatal cholestasis as first presentation of hyperargininemia is rare, but this disorder should be included in the differential diagnosis of unexplained cholestasis in the neonate. In fact, these two cases suggest that arginase deficiency may be the cause of cholestatic liver disease.
Patienteninformationen – vom Paternalismus zum Empowerment
Authors: Büchter Roland , Bastian Hilda , Waltering Andreas
Published: January 2011

Einleitung

Patienteninformationen sind traditionell paternalistisch und verfolgen mit wenig Erfolg das Ziel, das Verhalten von Patienten zu steuern. Patientenzentrierte Informationen erkennen die Kompetenzen von Patienten an und verfolgen das Ziel, die Ressourcen von Patienten zu stärken und sie dazu zu befähigen, einen größeren Einfluss auf ihre persönlichen Gesundheits- und Lebensziele zu nehmen. Dieser Artikel stellt die verschiedenen Gegensätze gegenüber.