bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural stability and electronic properties of low-index surfaces of SnS
Authors: Tritsaris Georgios A. , Malone Brad D. , Kaxiras Efthimios
Published: May 2014

Thin film photovoltaic cells are increasingly important for cost-effective solar energy harvesting. Layered SnS is a promising absorber material due to its high optical absorption in the visible and good doping characteristics. We use first-principles calculations based on density functional theory to study structures of low-index surfaces of SnS using stoichiometric and oxygen-containing structural models, in order to elucidate their possible effect on the efficiency of the photovoltaic device. We find that the surface energy is minimized for the surface with orientation parallel to the layer stacking direction. Compared to stoichiometric surfaces, the oxygen-containing surfaces exhibit fewer electronic states near the band gap. This reduction of near-gap surface states by oxygen should reduce recombination losses at grain boundaries and interfaces of the SnS absorber, and should be beneficial to the efficiency of the solar cell.
Interaction of Sn atoms with defects introduced by ion implantation in Ge substrate
Authors: Taoka Noriyuki , Fukudome Motoshi , Takeuchi Wakana , Arahira Takamitsu , Sakashita Mitsuo , Nakatsuka Osamu , Zaima Shigeaki
Published: May 2014

The interaction of Sn atoms with defects induced by Sn implantation of Ge substrates with antimony (Sb) as an n-type dopant and the impact of H2 annealing on these defects were investigated by comparison with defects induced by Ge self-implantation. In the Ge samples implanted with either Sn or Ge, and annealed at temperatures of less than 200 °C, divacancies, Sb-vacancy complexes with single or double acceptor-like states, and defects related to Sb and interstitial Ge atoms were present. On the other hand, after annealing at 500 °C in an N2 or H2 atmosphere, defects with different structures were observed in the Sn-implanted samples by deep level transition spectroscopy. The energy levels of the defects were 0.33 eV from the conduction band minimum and 0.55 eV from the valence band maximum. From the capacitance-voltage (C-V) characteristics, interaction between Sn atoms and defects after annealing at 500 °C was observed. The effect of H2 annealing at around 200 °C was observed in the C-V characteristics, which can be attributed to hydrogen passivation, and this effect was observed in both the Ge- and Sn-implanted samples. These results suggest the presence of defects that interact with Sn or hydrogen atoms. This indicates the possibility of defect control in Ge substrates by Sn or hydrogen incorporation. Such defect control could yield high-performance Ge-based devices.
Iron contamination in cast quasi-single crystalline silicon ingots
Authors: Li Zaoyang , Liu Lijun , Zhou Genshu
Published: May 2014

Iron is an important metallic impurity in crystalline silicon for solar cells and it can significantly influence the minority carrier lifetime. We numerically investigated the transport and distribution characteristics of iron impurity in the directional solidification process for quasi-single crystalline (QSC) silicon ingots, and attempted to reveal the relationship between the distributions of iron concentration and the minority carrier lifetime map. Additionally, the seed preservation time was varied to investigate its influence on the diffusion and distribution of iron impurity. The results show that iron diffusion from the silicon melt to the seed crystal during the preservation process can lead to a peak of iron concentration near the seed-crystal interface at the early stage of solidification. This peak gradually disappears during crystal growth, and iron diffusion results in a large region enriched with iron at the ingot bottom after complete solidification. Therefore, we conclude that the iron impurity is related to the large low lifetime region at the ingot bottom. We also discussed the effect of iron contamination on the high-low-high lifetime distribution pattern in the axial direction near the seed-crystal interface, which is a phenomena sometimes reported in QSC silicon ingots. The effect of seed preservation time on iron contamination in the QSC silicon ingot was also investigated. We found that the single-crystalline seed is highly contaminated even after a short time of seed preservation.
Reliable reduction of Fermi-level pinning at atomically matched metal/Ge interfaces by sulfur treatment
Authors: Kasahara K. , Yamada S. , Sakurai T. , Sawano K. , Nohira H. , Miyao M. , Hamaya K.
Published: May 2014

This study demonstrates that by using a sulfur (S) treatment on the Ge surface, a reduction in Fermi level pinning can reproducibly be achieved at atomically matched metal/Ge(111) interfaces. The Schottky barrier height for p-type Ge can be controlled by changing the metal work function despite the metal/Ge junctions. The results indicate that the combination of atomic-arrangement matching and S treatment can remove extrinsic factors influencing Fermi level pinning at metal/Ge interfaces.
Piezoelectricity and ferroelectricity in odd-odd nylons with long alkane segments
Authors: Liu Shaobing , Cui Zhe , Fu Peng , Liu Minying , Zhang Yanchang , Jia Rufeng , Zhao Qingxiang
Published: May 2014

Piezoelectricity and ferroelectricity in odd-odd nylon 11,11 and nylon 13,13 are detected. The results indicate that the γ-phase is responsible for the high piezoelectric and ferroelectric response. The piezoelectric strain coefficient, d33, as high as −3.9 and −4.1 pC/N is obtained at room temperature for stretched nylon 11,11 and nylon 13,13 films, respectively. The coercive electric field, Ec, values of about 55 and 88 MV/m are obtained for nylon 11,11 and nylon 13,13 films, respectively. And a remanent polarization, Pr, about 40 mC/m2 has been found in both films. Compared with nylon 11,11, the lower coercive electric field (Ec) in nylon 13,13 is attributed to its longer alkyl chains. These odd-odd nylons have the potential in electroactive applications.
James Henry Michael 1920–2001
Authors: Murray M. K. , Parrott D.
Published: May 2014

Professor James Henry ('Jim') Michael 1920–2001 was elected to the Australian Academy of Science in 1973. Born in Port Augusta, Jim saw active service during the Second World War. Returning to Adelaide, he completed a PhD in pure mathematics and began a distinguished career as an international expert in mathematical analysis. As well as being a mathematician, Jim was a keen golfer and shooter. Jim is remembered as a quiet, gentle man of few words but great integrity. A devoted family man, he is survived by his wife Pat, his daughter Mary Jane, his son Philip and his two grandchildren Ian and Tim Michael.
First record of vancomycin‐resistant Enterococcus faecium in Canadian wildlife
Authors: Oravcova Veronika , Janecko Nicol , Ansorge Antonin , Masarikova Martina , Literak Ivan
Published: May 2014

In this study, we focused on spreading of vancomycin‐resistant enterococci (VRE) to the environment. We studied that weather crows in Canada may be carriers and potentially reservoirs of VRE with vanA gene. We have found one multi‐resistant isolate of Enterococcus faecium sequence type (ST) 448 with vanA gene on Prince Edward Island. This study is the first report of VRE in Canadian wildlife.
X chromosome parental origin and aortic stiffness in turner syndrome
Authors: Abd‐Elmoniem Khaled Z. , Bakalov Vladimir K. , Matta Jatin R. , Muldoon Nancy , Hanover John A. , Bondy Carolyn A. , Gharib Ahmed M.
Published: May 2014

Introduction

Aortic abnormalities contribute to increased morbidity and mortality of women with Turner syndrome (TS). Impaired aortic stiffness may prove to have clinical prognostic value in TS as is the case in other diseases such as Marfan syndrome, diabetes and hypertension. Additionally, the parental origin of the X chromosome in TS may influence aortic stiffness.

Objective

To assess the relation between X chromosome parental origin and aortic stiffness in TS patients.

Methods

Twenty‐four subjects with TS participated in this cross‐sectional study at a tertiary care centre. The parental origin of the X chromosome was determined. Cardiac‐gated multidetector computerized tomography (MDCT) was performed and distensibility of the ascending aorta (AA), a measure of aortic stiffness, was calculated.

Results

Fourteen women were Xm (maternal origin) and 10 were Xp (paternal origin) for their inheritance of the single X chromosome. Age, body size, blood pressure and AA areas were similar in the two groups. However, the calculated AA distensibility was significantly lower in the Xm group (2·8 ± 1·1 mm/Hg) than in the Xp group (4·1 ± 1·5 mm/Hg); P < 0·05.

Conclusion This study demonstrates that TS subjects that inherit their single X chromosome from their mother (Xm) have a significantly stiffer aorta compared with the TS with a paternally originating X chromosome (Xp), consistent with a potentially greater risk for cardiovascular complications. These findings suggest that parental chromosomal analysis and aortic stiffness measurements would be useful for the risk assessment and clinical management of TS patients.
A prospective cohort study on the impact of smoking on soft tissue alterations around single implants
Authors: Raes Stefanie , Rocci Antonio , Raes Filiep , Cooper Lyndon , De Bruyn Hugo , Cosyn Jan
Published: May 2014

Objectives

To compare smokers to non‐smokers in terms of soft tissue alterations following single implant treatment in healed bone.

Material and methods

Non‐smoking and smoking patients with sufficient bone volume in need of a single implant in the anterior maxilla (15–25) were consecutively recruited in three centres. Conventional single implant surgery was performed and an immediate provisional crown was installed. Eight to 12 weeks later, the latter was replaced by a permanent one (baseline). Papilla regrowth and midfacial recession was registered after 2 years of function.

Results

The sample consisted of 39 non‐smokers (21 females; mean age 42) and 46 smokers (22 females; mean age 45). Smokers had three early failures, whereas all implants integrated successfully in non‐smokers. Statistically significant papilla regrowth was observed in non‐smokers (distal 0.63 mm, mesial 0.76 mm), whereas smokers showed stable papillae (between cohorts: P ≤ 0.025). Midfacial soft tissue level demonstrated statistically significant regrowth in non‐smokers (0.53 mm), whereas it remained stable in smokers (between cohorts: P = 0.004).

Conclusion

Smokers failed to demonstrate papilla regeneration and showed more midfacial recession following single implant treatment when compared to non‐smokers.
Placing the River in Context: James C. Knox, Fluvial Geomorphology, and Physical Geography
Authors: Bendix Jacob , Vale Thomas R.
Published: May 2014

We characterize the fluvial geomorphology research of James C. Knox by considering five of his scholarly papers, selected to illustrate not only some of Knox's methods and results but also his conviction that stream‐sediment interactions are intricately connected to a range of environmental variables reflecting the scope of physical geography. Those variables, as we discuss, included hydrology, climate, vegetation, position in the drainage network, and human land use. We conclude with the suggestion that Knox's breadth of geomorphic vision was echoed in his approach to his own academic career, and his belief that academic institutions are best served by broad and integrative perspectives.
Within‐Country Growth Options Versus Across‐Country Switching Options in Foreign Direct Investment
Authors: Song Sangcheol , Makhija Mona , Lee Seung‐Hyun
Published: May 2014

This article considers the value associated with foreign direct investment under different types of uncertainty related to the international context. We examine how configuring foreign direct investments differently within and across countries provides the firm with flexibility under exchange rate uncertainty and market growth uncertainty. We find that across‐country switching options embedded in investments dispersed across countries are more associated with higher firm value under high exchange rate uncertainty, while within‐country growth options embedded in those concentrated within countries are more associated with higher market growth uncertainty. We also find that across‐country switching options call for higher ownership levels, while within‐country growth options require lower ownership levels in international investment portfolio.
Firm Value Effects of Global, Regional, and Local Brand Divestments in Core and Non‐Core Businesses
Authors: Depecik Baris , van Everdingen Yvonne M. , van Bruggen Gerrit H.
Published: May 2014

In this article, we investigate the effect of brand divestments on firm value. We integrate two common motives for focus‐increasing brand divestitures—global branding and refocusing on core businesses—in a single common framework. In particular, we investigate the effects of divesting local/regional/global brands in core businesses and local/regional/global brands in non‐core businesses on firm value. Analyzing 205 divestment announcements in the global food and beverages industry, we find that, in most cases, brand divestments destroy firm value. Only when firms divest local or regional brands in non‐core businesses is the effect on firm value positive.
Online consensus conferences for clinical guidelines development – a survey among participants from the International Guidelines for the Treatment of Actinic Keratosis
Authors: Werner Ricardo N. , Jacobs Anja , Rosumeck Stefanie , Nast Alexander
Published: May 2014

Rationale, aims and objectives

Guideline development requires considerable time and financial resources. New technical devices such as software for online conferences may help to reduce time and financial efforts of guidelines development. The present survey may serve as an explorative pilot for a future study to determine the technical feasibility, acceptability and possible weaknesses of online consensus conferences for clinical guidelines development.

Methods

An anonymous online survey was conducted among participants in the online consensus conference of the International League of Dermatological Societies (ILDS) Guidelines for the Treatment of Actinic Keratosis.

Results

The majority of participants reported no technical problems with the participation in the online consensus conference; one participant had substantial technical problems accountable to a regional telephone breakdown. The majority of participants would not have preferred a traditional face‐to‐face conference, and all participants rated online consensus conferences for international guidelines as absolutely acceptable. Rates of acceptance were particularly high among those participants with prior experience with consensus conferences. Certain aspects, particularly the possibilities of debating, were rated as possibly superior in face‐to‐face conferences by some participants.

Conclusions

The data from the online survey indicate that online consensus conferences may be an appropriate alternative to traditional face‐to‐face consensus conferences, especially within the frame of international guidelines that would require high travel costs and time. Further research is necessary to confirm the data from this explorative pilot study.
Induction of depressive‐like effects by subchronic exposure to cocaine or heroin in laboratory rats
Authors: Zilkha Noga , Feigin Eugene , Barnea‐Ygael Noam , Zangen Abraham
Published: May 2014

The effect of psychoactive drugs on depression has usually been studied in cases of prolonged drug addiction and/or withdrawal, without much emphasis on the effects of subchronic or recreational drug use. To address this issue, we exposed laboratory rats to subchronic regimens of heroin or cocaine and tested long‐term effects on (i) depressive‐like behaviors, (ii) brain‐derived neurotrophic factor (BDNF) levels in reward‐related brain regions, and (iii) depressive‐like behavior following an additional chronic mild stress procedure. The long‐term effect of subchronic cocaine exposure was a general reduction in locomotor activity whereas heroin exposure induced a more specific increase in immobility during the forced swim test. Both cocaine and heroin exposure induced alterations in BDNF levels that are similar to those observed in several animal models of depression. Finally, both cocaine and heroin exposure significantly enhanced the anhedonic effect of chronic mild stress. These results suggest that subchronic drug exposure induces depressive‐like behavior which is accompanied by modifications in BDNF expression and increases the vulnerability to develop depressive‐like behavior following chronic stress. Implications for recreational and small‐scale drug users are discussed.

image

In the present study, we examined the long‐term effects of limited subchronic drug exposure on depressive‐like symptoms. Our results demonstrate that short‐term, subchronic administration of either cocaine or heroin promotes some depressive‐like behaviors, while inducing alterations in BDNF protein levels similar to alterations observed in several animal models of depression. In addition, subchronic cocaine or heroin enhanced the anhedonic effect of chronic stress.
Identification and differential distribution of CART in the small intestine depending on the diet
Authors: Janiuk I. , Olkowski B. , Szczotka‐Bochniarz A.
Published: May 2014

This study was aimed at identifying and locating cocaine‐ and amphetamine‐regulated transcript (CART) in the small intestine of broilers in relation to the diet. The feeding regime of the chicks was based on diets largely consisting of maize and one of four protein sources: post‐extraction soya bean meal (SBM) or non‐GM seed meal – meal from traditional variety of soy seeds Glicine max (FFS) and meal from seeds of Lupinus angustifolius (LA) and Lupinus luteus L (LY). The presence of cocaine‐ and amphetamine‐regulated transcript immunoreactive (CART‐IR) in the wall of the small intestine of the chicks was determined on the basis of staining patterns produced by the immunohistochemical method (IHC). CART‐IR structures were found in the myenteric plexus (MP), submucosus plexus (SP), in endomucosal fibres, and fibres innervating miocytes and blood vessels in the muscularis membrane and adipocytes of the white adipose tissue (WAT) located on the perimeter of the serous membrane and single cells of the diffuse neuroendocrine system. Based on microscopic observation and result analysis, the lowest number of CART‐IR structures was identified in the group that was fed the SBM‐based diet. This study confirms previous observations concerning CART distribution in the gastrointestinal tract (GIT) of animal and broadens current knowledge by inclusion of chicken in the list of CART‐positive species. Moreover, this work provides evidence that dietary composition can be a factor that stimulates post‐prandial CART secretion in intestinal nerve structures.
FhaC takes a bow to FHA in the two‐partner do‐si‐do
Authors: Noinaj Nicholas , Buchanan Susan K.
Published: May 2014

FhaC is an outer membrane transporter from Bordetella pertussis belonging to the two‐partner secretion (TPS) pathway with its primary role being the secretion of the virulence factor filamentous haemagglutinin (FHA). FhaC serves as a model transporter of the TPS pathway and significant work has been done to characterize the role of FhaC in FHA secretion. Recent studies characterized interactions between FHA and the POTRA domains of FhaC, suggesting that secretion may involve a successive translocation mechanism mediated by β‐augmentation and/or electrostatic interactions. Moreover, it was also shown that reconstituted FhaC is necessary and sufficient to transport FHA into proteoliposomes. While the crystal structure of FhaC clearly suggests a role in transport, the putative transport pore is plugged by an N‐terminal α‐helix (H1 helix) that occludes access by FHA. Therefore, it has been proposed that the H1 helix must be expelled from the pore in order for secretion of FHA to occur. However, this has yet to be shown experimentally. Guérin et al. (2014) report the first direct experimental evidence to show that the FhaC H1 helix is quite dynamic and exchanges between closed and open states upon interaction with FHA.
A role of Anabaena sensory rhodopsin transducer (ASRT) in photosensory transduction
Authors: Kim So Young , Yoon Sa Ryong , Han SongI , Yun Yuna , Jung Kwang‐Hwan
Published: May 2014

In 2003, Anabaena sensory rhodopsin (ASR), a membrane‐bound light sensor protein, was discovered in cyanobacteria. Since then, a large number of functions have been described for ASR, based on protein biochemical and biophysical studies. However, no study has determined the in vivo mechanism of photosensory transduction for ASR and its transducer protein (ASRT). Here, we aimed to determine the role of ASRT in physiological photo‐regulation. ASRT is known to be related to photochromism, because it regulates the expression of phycocyanin (cpc‐gene) and phycoerythrocyanin (pec gene), two major proteins of the phycobilisome in cyanobacteria. By examining wild type and knockout mutant Anabaena cells, we showed that ASRT repressed the expression of these two genes. We also demonstrated physical interactions between ASRT, ASR, and the promoter regions of cpc, pec, kaiABC (circadian clock gene) and the asr operon, both in vitro and in vivo. Binding assays indicated that ASRT had different sites of interaction for binding to ASR and DNA promoter regions. ASRT also influenced the retinal re‐isomerization rate in dark through a physical interaction with ASR, and it regulated reporter gene expression in vivo. These results suggested that ASRT relayed the photosignal from ASR and directly regulated gene expression.
Cell dynamics in Hertwig's epithelial root sheath and surrounding mesenchyme in mice irradiated to the head
Authors: Ide Y , Nakahara T , Nasu M , Ishikawa H
Published: May 2014

Objective

To investigate the mechanisms that cause damage to root formation as a result of irradiation to the mouse head, morphological changes in molar dental roots and cell dynamics in Hertwig's epithelial root sheath (HERS), and surrounding mesenchymal tissue were examined.

Materials and Methods

To perform the experiments, 5‐day‐old C57BL/6 mice were randomly divided into three groups: the control group (0 Gy) and irradiated groups (10 and 20 Gy). Micro‐CT analysis, HE staining, immunohistochemistry analysis, and TUNEL assay were then performed.

Results

Roots in irradiated mice were dose‐dependently shorter than those of control mice. Cells located outside the root dentin, with abnormal morphology in irradiated mice, were positive for an odontoblast marker. HERS fragmentation occurred earlier in irradiated mice than in control mice, and HERS was trapped by the calcified apical tissue. A dose‐dependent reduction in the number of proliferating cells within the apical dental pulp and periapical periodontal ligament surrounding HERS was observed in irradiated mice. Apoptotic cells in the dental pulp and periodontal ligament surrounding HERS were hardly seen.

Conclusions

These results indicate that the early disappearance of HERS and the proliferative suppression of the surrounding mesenchymal cells, which was induced by irradiation, caused dental root malformation.
Validation of the Greek Version of the DN4 Diagnostic Questionnaire for Neuropathic Pain
Authors: Sykioti Panagiota , Zis Panagiotis , Vadalouca Athina , Siafaka Ioanna , Argyra Eriphili , Bouhassira Didier , Stavropoulou Evmorfia , Karandreas Nikolaos
Published: May 2014

Background

The Douleur Neuropathique 4 questionnaire (DN4) was developed by the French Neuropathic Pain Group and is a simple and objective tool, primarily designed to screen for neuropathic pain. The aim of our study is to validate the DN4 in the Greek language.

Methods

The study was set up as a prospective observational study. Two pain specialists independently examined patients and diagnosed them with neuropathic, nociceptive, or mixed pain, according to the International Association for the Study of Pain (IASP) definitions. A third and a fourth physician administered the DN4 questionnaire to the patients.

Results

Out of the 237 patients who met our inclusion criteria and had identical diagnoses regarding the type of pain, 123 were diagnosed with neuropathic, 59 with nociceptive, and 55 with mixed pain. Among patients with identical diagnoses of neuropathic or nociceptive pain, using a receiver operating characteristic (ROC) curve analysis, the area under the curve (AUC) was 0.92. A cutoff point of equal or greater than 4 resulted in a sensitivity of 93% and a specificity of 78%. Among patients suffering from pain with neuropathic element (neuropathic or mixed pain) or pain with no neuropathic element (nociceptive pain), using a ROC curve analysis, the AUC was 0.89. A cutoff point of equal or greater than 4 resulted in a sensitivity of 89% and a specificity of 78%.

Conclusion

The Greek version of DN4 is a valid tool for discriminating between neuropathic and nociceptive pain conditions in daily practice.
Evaluation of three herbicide resistance genes for use in genetic transformations and for potential crop protection in algae production
Authors: Bruggeman Andrew J. , Kuehler Daniel , Weeks Donald P.
Published: May 2014

Genes conferring resistance to the herbicides glyphosate, oxyfluorfen and norflurazon were developed and tested for use as dominant selectable markers in genetic transformation of Chlamydomonas reinhardtii and as potential tools for the protection of commercial‐scale algal production facilities against contamination by organisms sensitive to these broad‐spectrum herbicides. A synthetic glyphosate acetyltransferase (GAT) gene, when fitted with a strong Chlamydomonas promoter, conferred a 2.7×‐fold increase in tolerance to the EPSPS inhibitor, glyphosate, in transgenic cells compared with progenitor WT cells. A mutant Chlamydomonas protoporphyrinogen oxidase (protox, PPO) gene previously shown to produce an enzyme insensitive to PPO‐inhibiting herbicides, when genetically engineered, generated transgenic cells able to tolerate up to 136× higher levels of the PPO inhibitor, oxyfluorfen, than nontransformed cells. Genetic modification of the Chlamydomonas phytoene desaturase (PDS) gene‐based gene sequences found in various norflurazon‐resistant organisms allowed production of transgenic cells tolerant to 40× higher levels of norflurazon than nontransgenic cells. The high efficiency of all three herbicide resistance genes in producing transgenic cells demonstrated their suitability as dominant selectable markers for genetic transformation of Chlamydomonas and, potentially, other eukaryotic algae. However, the requirement for high concentrations of glyphosate and its associated negative effects on cell growth rates preclude its consideration for use in large‐scale production facilities. In contrast, only low doses of norflurazon and oxyfluorfen (~1.5 μm and ~0.1 μm, respectively) are required for inhibition of cell growth, suggesting that these two herbicides may prove effective in large‐scale algal production facilities in suppressing growth of organisms sensitive to these herbicides.
Protothecosis in hematopoietic stem cell transplantation: case report and review of previous cases
Authors: Macesic N. , Fleming S. , Kidd S. , Madigan V. , Chean R. , Ritchie D. , Slavin M.
Published: May 2014

Prototheca species are achlorophyllus algae. Prototheca wickerhamii and Prototheca zopfii cause human disease. In immunocompetent individuals, they cause soft tissue infections and olecranon bursitis, but in transplant recipients, these organisms can cause disseminated disease. We report a fatal case of disseminated P. zopfii infection in an hematopoietic stem cell transplant (HSCT) recipient with bloodstream infection and involvement of multiple soft tissue sites. We review all previous cases of protothecosis in HSCT reported in the literature. Protothecosis is uncommon after HSCT, but has a disseminated presentation that is frequently fatal. It is commonly misidentified as a yeast. Tumor necrosis factor‐alpha inhibitors and contamination of central venous catheters may contribute to development of protothecosis. Optimal treatment approaches are yet to be defined. New agents such as miltefosine may be possible future therapies.
Rab5 and Ndfip1 Are Involved in Pten Ubiquitination and Nuclear Trafficking
Authors: Li Yijia , Low Ley‐Hian , Putz Ulrich , Goh Choo‐Peng , Tan Seong‐Seng , Howitt Jason
Published: May 2014

The spatial regulation of Pten is critical for its role as a tumour suppressor with both nuclear and cytoplasmic locations being implicated with distinct functions. In the cytoplasm, Pten plays a central role in opposing PI3K/Akt cell signalling, whereas in the nucleus, Pten is important for maintaining genome stability and enhancing the tumour suppressor activity of APC‐CDH1. Despite this diversity in protein function at different subcellular locations, there is limited knowledge on how Pten is able to find different cellular niches. Here, we report that Rab5 GTPase is required for efficient trafficking and ubiquitination of Pten on endosomes inside the cytosol. Using bimolecular fluorescence complementation (BiFC) for imaging protein interactions, we observed that ubiquitinated Pten is localized to peri‐nuclear and nuclear regions of the cell. Nuclear trafficking of Pten required both Rab5 as well as the E3 ligase adaptor protein Ndfip1. Rab5 colocalization with Pten was observed on endosomes and expression of a dominant negative form of Rab5 significantly reduced Pten ubiquitination and nuclear trafficking. Genomic deletion of Ndfip1 abrogated nuclear trafficking of ubiquitinated Pten, even in the presence of Rab5. Our findings show that endosomal trafficking and ubiquitination are important mechanisms for the subcellular distribution of Pten.
Leukoreduced blood transfusion does not increase circulating soluble markers of inflammation: a randomized controlled trial
Authors: Jiwaji Zoeb , Nunn Kieran P. , Conway‐Morris Andrew , Simpson A. John , Wyncoll Duncan , Rossi Adriano G. , Walsh Timothy S. ,   RELIEVE Trial Investigators
Published: May 2014

Background

Transfused blood may have immunomodulatory and proinflammatory effects. We report the first randomized study exploring whether leukoreduced red blood cell (RBC) transfusion increases circulating proinflammatory mediators, markers of neutrophil activation, and the acute‐phase response in critically ill adults.

Study Design and Methods

Eighty‐four patients were recruited from six general intensive care units in the United Kingdom as part of a laboratory study nested within a parallel‐group randomized trial comparing restrictive and liberal leukoreduced RBC transfusion strategies in critically ill patients aged more than 55 years with measured hemoglobin concentrations of not more than 90 g/L (ClinicalTrials.gov NCT00944112). Forty‐one patients received transfusion and 43 did not receive transfusion. Plasma was sampled at baseline, 6 hours, and 24 hours after randomization or transfusion, and concentrations of interleukin (IL)‐1β, IL‐2, IL‐4, IL‐5, IL‐6, IL‐8, IL‐10, IL‐12‐p70, interferon‐γ, tumor necrosis factor‐α, human neutrophil elastase, soluble L‐selectin, and C‐reactive protein were measured using cytokine bead array analysis and an enzyme‐linked immunosorbent assay.

Results

Patients who received transfusion did not have significantly different inflammatory biomarker plasma concentrations at the time points compared to those who did not receive transfusion, with the exception of IL‐8 concentrations at 24 hours, which were reduced in the transfused group (p = 0.02). After adjustment for baseline inflammatory biomarker concentrations, there were no significant differences between patients who received transfusion and those who did not.

Conclusion

Concentrations of measured biomarkers were not significantly increased during the first 24 hours after leukoreduced RBC transfusion. These data do not support the contention that leukoreduced RBC transfusion is associated with a proinflammatory response in the general adult critically ill population.
Evaluation of standardized endodontic paper point tear test in New Zealand white rabbits and comparison between corneal sensitivity followed tear tests
Authors: Lima Leandro , Lange Rogério Ribas , Turner‐Giannico Amália , Montiani‐Ferreira Fabiano
Published: May 2014

Objective

To evaluate endodontic paper point tear test (PPTT) in rabbits and compare changes in corneal touch threshold (CTT) induced by Schirmer tear test (STT) andPPTT. Normal corneal sensitivity recovery time after both tear tests was also measured. Also, meanPPTTandSTTvalues were obtained.

Methods

Tear production of 20 eyes, from 10 rabbits, was evaluated usingSTTand thePPTT. Central corneal touch threshold was measured by a Cochet‐Bonnet esthesiometer before any tear test was performed (zero time), immediately after the test (1 min), and consecutively at 6, 11, 16, and 26 min. Tests were conducted on three consecutive days: Day 1 – control condition, no tear tests performed only theCTT; Day 2 –CTTbefore and afterPPTT; and Day 3 –CTTbefore and afterSTT.CTTvalues were compared using repeated measuresANOVA.

Results

Corneal touch threshold was significantly increased for at least 16 min afterSTT, indicatingSTTcauses corneal discomfort. No difference was found betweenCTTfollowingPPTTand controls, indicatingPPTTcaused minimal corneal discomfort. The mean (±SD) value forSTTwas 5.2 ± 1.0 mm/min and forPPTTwas 13.8 ± 1.5 mm/min.

Discussion

The aqueous fraction of rabbit's tears can be successfully measured byPPTT. This report established reference values forPPTTin rabbits. Additionally, the absence of a significant difference inCTTafterPPTTcompared with controls shows thatPPTTis well tolerated by rabbits. Considering the improved comfort (compared withSTT), accuracy, and low cost,PPTTis a bona fide method of measuring aqueous tear production in rabbits.
Extensive pulmonary involvement with raltegravir-induced DRESS syndrome in a postpartum woman with HIV
Authors: Yee Brittany Elizabeth , Nguyen Nghia Hoang , Lee Daniel
Published: May 2014

An 18-year-old postpartum woman with HIV, on lamivudine–zidovudine, lopinavir–ritonavir and raltegravir, presented with a 1-week history of rash and fevers. Initially admitted to obstetrics and gynaecology service for treatment of possible endometritis, she was transferred to the HIV medicine service for high fever, respiratory distress, hypotension and tachycardia. On admission, she was febrile (102°F) with findings of cervical and submandibular lymphadenopathy, diffuse morbilliform rash, generalised pruritus, facial oedema, and oedematous hands and feet. Consultations to various specialty services were initiated to rule out infectious, dermatological, rheumatological and drug-induced aetiologies. On the fourth day of hospitalisation, laboratory findings of significant eosinophilia and hepatitis (alanine aminotransferase 147 IU/L and aspartate aminotransferase 124 IU/L), in conjunction with the identification of the timing of medication use, led to a diagnosis of DRESS (drug reaction with eosinophilia and systemic symptoms) syndrome secondary to raltegravir. After discontinuing raltegravir and starting prednisone, her DRESS symptoms completely resolved.
Evacuation under limited visibility
Authors: Frank Guillermo A. , Dorso Claudio O.
Published: May 2014

A multiplicity of situations can trigger off an evacuation of a room under panic conditions. For "normal" (with "normal" meaning absence of obstacles, perfect visibility, etc.) environmental conditions, the "faster is slower" effect dominates the dynamics of this process. It states that as the pedestrians desire to reach the exit increases, the clogging phenomena delays the time to get out of the room. But, environmental conditions are usually far from "normal." In this work, we consider that pedestrians have to find their way out under low visibility conditions. Some of them might switch to a herding-like behavior if they do not remember where the exit was. Others will just trust on their memory. Our investigation handles the herding and memory effects on the evacuation of a single exit room with no obstacles. We also include a section on how signaling devices affect the evacuation process. Unexpectedly, some low visibility situations may enhance the evacuation performance. This can be resumed as a second paradoxical result, since we demonstrated in an earlier investigation that "clever is not always better" G. A. Frank and C. O. Dorso, Physica A 390, 2135 (2011).
Temperature dependant electrical properties of formyl-TIPPCu(II)/p-Si heterojunction diode
Authors: Khan Dil Nawaz , Sayyad Muhammad Hassan , Wahab Fazal , Tahir Muhammad , Yaseen Muhammad , Munawar Munawar Ali , Ali Mukhtar
Published: May 2014

This paper reports the temperature dependent electrical characterization of formyl- TIPPCu (II)/p- Si heterojunction diode which was fabricated by growing thin films of formyl- TIPPCu (II) on the p-type silicon substrate by thermal sublimation technique. The variation in electrical characteristics of the fabricated devices has been systematically investigated as the function of temperature by using current–voltage (I–V) measurements in the temperature range 299–339 K. The diode parameters like ideality factor, zero bias barrier height and parasitic series resistance have been found to be strongly temperature dependant. The zero bias barrier height increases while ideality factor and series resistance decreases with increasing temperature.
Pricings and hedgings of the perpetual Russian options
Authors: Li Weiping , Chen Su
Published: May 2014

In this paper, we study the optimal stopping time and the optimal stopping boundary for the perpetual Russian option under the diffusion process. The general continuation region is characterized by a function b(p,t) depending on both variables t and the maximum value of the stock and initial starting value P0. Previous studies assume that the continuation region is given by a function depending upon the time t only. This is unreal hypothesis for the diffusion to achieve. Our result shows that the perpetual Russian option can be described by a Black–Scholes equation over the continuation region and smooth boundary conditions on the optimal stopping boundary. Furthermore, we develop an evaluation method from the lookback option on a stopping time, and establish the Greek letters for the perpetual Russian option. We obtain the exact upper bound for the prices of the perpetual Russian options and demonstrate that both the payoff and the optimal stopping time are path-dependent by Monte Carlo simulations.
Improved Catalytic Reactor for the Electrochemical Promotion of Highly Dispersed Ru Nanoparticles with CeO2 Support
Authors: Dole Holly Andrea Eva , Safady Luís Felipe , Ntais Spyridon , Couillard Martin , Baranova Elena A.
Published: May 2014

An improved design for a catalytic reactor for electrochemical promotion of highly dispersed catalysts was presented and compared to that of a plug flow-type reactor for the model reaction of ethylene oxidation. Electrochemical cells were prepared with low particle size (1.1 nm) Ru nanoparticles (RuNPs) which were supported on a mixed ionic-electronic conductor, CeO2, with a low metal loading (1 wt%), interfaced with a YSZ electrolyte. Comparable catalytic performance between the two reactors was observed for both open-circuits measurements. However, the rate enhancement ratio in the single-chamber capsule (SCC) reactor was found to be 1.6 compared to 1.4 for the plug flow-type reactor for an applied current of -5μA. These results were attributed to better electrical contact to the isolated RuNPs. Furthermore, the SCC reactor is simple to assemble and provides an intimate contact between the RuNPs/CeO2 catalyst and the current collector (i.e., gold mesh).
Effect of Carbon Dioxide on the Cathodic Performance of Solid Oxide Fuel Cells
Authors: Cetin Deniz , Yu Yang , Luo Heng , Lin Xi , Ludwig Karl , Basu Soumendra Nath , Pal Uday Bhanu , Gopalan Srikanth
Published: May 2014

In this paper, we present results of synchrotron studies of the impact of carbon dioxide exposure on Sr surface segregation phenomenon in La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF-6428), a promising cathode material for solid oxide fuel cells (SOFCs). The morphological changes at the surface were examined by AFM studies. These are combined with computational studies of the stability of the LSCF cathode to carbon dioxide exposure. The kinetics and thermodynamics of the segregation are discussed. The longer term goal of this study is to identify cathode compositions which have long term stability to exposure to trace anode side gases.
Performance of MIEC Cathodes in SOFC Stacks Evaluated by Means of FEM Modeling
Authors: Geisler Helge , Kromp Alexander , Weber André , Ivers-Tiffée Ellen
Published: May 2014

In planar solid oxide fuel cell (SOFC) stacks, anode supported cells are connected in series and in parallel by metal interconnectors (MIC), which always goes to the cost of performance.Further insight was gained with the help of a 2D-FEM repeat unit model, accounting for ohmic and polarisation losses on stack level. Implemented physical processes are i) gas diffusion in the porous electrodes, ii) electric/ionic conduction in the electrodes/electrolyte iii) and electrochemical electrode reactions. Material and kinetic parameters have been determined experimentally and the model is validated against measured data over a broad range of operating conditions.The 2D-FEM repeat unit model calculates performance in dependence on cathode dimensions, microstructure and chemical composition versus MIC-flowfield design. The calculations show, that performance is mainly limited by the oxidant gas transport underneath the contact rib for a given flowfield design. Thereby a well-chosen cathode thickness increases the overall power output of a planar SOFC stack most efficiently.
Carbonate Fuel Cell Anode: A Review
Authors: Hilmi Abdelkader , Yuh Chao-Yi , Farooque Mohammad
Published: May 2014

Porous nickel alloyed anodes (Ni-Al and / or Ni-Cr) have demonstrated excellent mechanical, chemical and electrochemical stability during MCFC stack endurance tests. These electrodes showed no discernible change in the morphologies, pore structure and particles size. Combination of polarization studies and different diagnostic techniques showed that the anode reaction is primarily under mass-transfer control. Improved anode structure with balanced pores for gas diffusion and electrolyte retention was developed. The current focus of technology development is on improving wettability, reducing anode material cost and improving the manufacturing process
The Role of Mixed Conduction in W-WO3 Redox Kinetics
Authors: Milshtein Jarrod David , Pal Uday Bhanu , Gergel Diana , Basu Soumendra Nath , Gopalan Srikanth
Published: May 2014

The tungsten–tungsten oxide (W-WO3) materials system has shown promise as a medium for grid level storage and solar energy conversion. In both these applications the thermal energy transfer is accompanied by a redox reaction in the W-WO3 couple. For viability of this system as an energy storage medium, it is important to have facile redox kinetics that allow for rapid energy storage and release. Facile kinetics are also required in the utilization of this system in solar syngas production. We show that adding an ionic conducting phase, yttria-stabilized zirconia (YSZ), enhances the redox kinetics. Specifically, the reduction kinetics of the WO3-W reaction are facilitated. As a control, a redox experiment with a filler material that is not an ionic conductor did not show such an enhancement in the kinetics. Chemical reaction rates were determined by transient thermogravimetry, and the data were analyzed using relevant kinetic and transport theory.
Ionic Conductivity of Zirconia-Scandia-Dysprosia Solid Electrolyte
Authors: Grosso Robson Lopes , Muccillo Eliana Navarro Santos
Published: May 2014

The effects of small additions of dysprosia (1, 1.5 and 2 mol%) to zirconia-10 mol% scandia were investigated by spectroscopic techniques. The main purpose of this work was to study the influence of the rare earth additive on the structural and electrical properties of the zirconia-scandia solid electrolyte. The compositions were prepared by solid state synthesis and the characterization techniques comprise X-ray diffraction, Raman spectroscopy and impedance spectroscopy. Fully stabilization of the cubic structure occurred for 2 mol% dysprosia addition. For lower additive contents the cubic reflections coexist with those of the β-rhombohedral phase. The additive was also found to inhibit the densification of the zirconia-scandia solid electrolyte. The activation energy for oxide ion conduction is 1.31 eV.
Oxygen Reduction Properties of La0.1Sr0.9Co0.8Fe0.2O3-δ Cathode for SOFC Using Electrochemical Method
Authors: Im Ha-Ni , Choi Moon-Bong , Jeon Sang-Yun , Singh Bhupendra , Song Sun-Ju
Published: May 2014

The oxygen reduction reaction (ORR) at the La0.1Sr0.9Co0.8Fe0.2O3-δ (LSCF1982)/Ce0.9Gd0.1O2 (GDC) interface is investigated by electrochemical impedance spectroscopy (EIS) in 550-650 oC range under different oxygen partial pressure (pO2). The analysis of impedance diagrams revealed the presence of at least three processes involved in ORR. The reaction at high-frequency region was assigned to the transport of oxide ions within the electrode structure and the electrode/electrolyte interface, whereas the reaction at the low frequency region is the adsorption of gaseous oxygen molecule from the gas phase onto the active electrode site.
Investigation of Strong Metallic Ta Reduction in ZrO2/Ta2O5 Multi-Laminate Layer Growth
Authors: Cho Hyunchol , Park K W , Ahn J H , Park C H , Cho H J , Yeom S J , Hong K , Kwak N J
Published: May 2014

Thin ZrO2/Ta2O5 multi-laminate layer of ~10 nm was grown by atomic layer deposition (ALD) method and it was discussed about the metallic Ta reduction at the interface between ZrO2 and Ta2O5. Metallic Ta 4f7/2 peak was observed inside of the layer from the result of XPS analysis and it is thought that strong metallic Ta reduction was happened between Ta2O5 and as-coming Zr source (or ZrO2). Also, these results were supported by the Gibbs free energy calculations.
Cyclic Plasma Treatment during ALD Hf1-XZrxO2 Deposition
Authors: Bhuyian Mdnasiruddin , Misra Durga , Tapily Kandabara , Clark Robert , Consiglio Steve , Wajda Cory , Nakamura G. , Leusink Gert
Published: May 2014

Effect of SPA Ar plasma on the reliability of intermediate plasma (DSDS) treated ALD Hf1-xZrxO2 samples with x=0, 0.31, 0.8 were investigated. The MOS capacitors (MOSCAP) were subjected to a constant field stress of 27.5 MV/cm in the gate injection mode and the stress-induced flat-band voltage shifts and stress induced leakage currents were monitored. The dielectric film deposited without any intermediate step (As-Dep), having the same number of ALD cycles as DSDS samples was used as the control sample. It was observed that plasma exposure enhances the quality of high-k film by reducing the number of intrinsic traps in the film and Zr addition further enhances the reliability. Breakdown characteristics also confirm this behavior. Electron affinity variation in HfO2 and ZrO2 and Zr variation seems to contribute to the improvement in DSDS Hf1-xZrxO2 (x=0.8) by suppressing the oxide trap formation as observed in the Weibull characteristics. DSDS Hf1-xZrxO2 with x=0.8, therefore, demonstrates a superior EOT downscaling ability and good reliability performance.