bluuebunny/crossref_metadata_2025 huggingface dataset:
Cysteine and Methionine Derivatives of Aminophenol Ligands: Synthesis, Iron Complexation, Magnetic, Electronic and Redox Investigation
Authors: Sheykhi Hamid , Safaei Elham
Published: January 2014

Two new Cysteine and Methionine derivatives of aminophenol ligands (HLCys and HLMet) were synthesized by a convenient procedure. The ligands were characterized by 1H NMR, 13C NMR and IR spectroscopies, ESI‐MS, elemental analysis and optical activity measurements. Iron(III) complexes (FeLCys and FeLMet) of these ligands were synthesized and characterized by spectroscopic, magnetic susceptibility studies and cyclic voltammetry techniques. The molecular structure of FeLCys and FeLMet determined by ESI‐MS consist of two ligands coordinated to Fe(III) centers. The magnetic susceptibility measurement indicates the monomeric complexes with paramagnetic properties. Both complexes undergo metal‐centred reduction, and ligand‐centred oxidation.
DC‐STAMP, the Key Fusion‐Mediating Molecule in Osteoclastogenesis
Authors: Zhang Chengcheng , Dou Ce , Xu Jianzhong , Dong Shiwu
Published: January 2014

As a member of the mononuclear phagocyte system, osteoclasts (OC) absorb the bone matrix and participate in bone modeling by keeping a balance with osteoblasts (OB) and stromal cells. Mature OC derive from the fusion of mononuclear osteoclasts (mOC) and the fusion is considered as the indispensable process for the osteoclastogenesis and absorbing activity of OC. DC‐STAMP (dendritic cell‐specific transmembrane protein) has been validated playing a key role in the fusion of mOC. DC‐STAMP is mainly expressed in OC, macrophages and dendritic cells (DC). While DC‐STAMP was discovered in DC, more attentions have been paid to DC‐STAMP in OC in this decade. This review will mainly focus on the function of DC‐STAMP in OC. Studies on DC‐STAMP in DC may also provide new sight for the study of DC‐STAMP in OC. Since the function of DC‐STAMP is still poorly understood and few studies have been implemented for illustration, many issues are still unknown and need to be revealed. We will also discuss these questions in this review. J. Cell. Physiol. 229: 1330–1335, 2014. © 2014 Wiley Periodicals, Inc.
Molecular virology of hepatitis B virus, sub‐genotype C4 in northern Australian Indigenous populations
Authors: Littlejohn M. , Davies J. , Yuen L. , Edwards R. , Sozzi T. , Jackson K. , Cowie B. , Tong S. , Davis J. , Locarnini S.
Published: January 2014

Indigenous Australians experience a significant health burden from chronic hepatitis B infection; however, the strain of hepatitis B virus (HBV) found among Indigenous Australians has not been well characterized. Blood samples were collected from 65 Indigenous Australians with chronic HBV infection from across the Top End of Australia's Northern Territory. Phylogenetic analysis of HBV from these samples revealed that 100% of the isolates were genotype C, sub‐genotype C4, expressing the serotype ayw3. This strain is a divergent group within the HBV/C genotype, and has only been described in Indigenous Australians. Evidence of recombination was suggested by discordant phylogenetic clustering of the C4 sequences when comparing the full genome to the surface region and confirmed by recombination analysis which showed the surface gene region to be most closely related to genotype J, while the remaining regions of the genome were most similar to genotype C sequences. Mutational analysis revealed the presence of multiple mutations that have been linked with more rapid liver disease progression and an increased risk of hepatocellular carcinoma. These mutations were detected in the majority of sequences examined. Variants associated with vaccine failure were detected as the predominant viral quasi‐species in 3/35 samples. In summary, the HBV C4 variant found in this population has a high potential to cause advanced liver disease and to escape vaccination programs. Further in vitro functional and natural history studies are warranted in order to determine the clinical and public health consequences of infection with the HBV C4 variant in these communities. J. Med. Virol. 86:695–706, 2014. © 2014 Wiley Periodicals, Inc.
Conjugated Polymers Featuring Oxacyclophane‐Scaffolded π‐Stacking Interactions
Authors: Mangalum Anshuman , Morgan Brad P. , Tennyson Andrew G. , Smith Rhett C.
Published: January 2014

An oxacyclophane framework is modified to include π‐conjugated segments positioned so as to allow an optimized face‐to‐face π‐stacking interaction between them. This unique architecture is first employed for the preparation of model compounds with defined interaction between two small molecular organic chromophores. The interaction allows facile through‐space energy transfer between the chromophores when they are held in the appropriate geometry. The oxacyclophane is thus employed in a polymer with consecutive short stretches of phenylene ethynylene such that polymer chain conjugation requires through‐space interaction between segments rather than the through‐bond π‐conjugation that typifies traditional conjugated polymers. The extent of the through‐space interactions along the polymer backbone is explored through photophysical measurements, calculations, X‐ray diffraction, and comparison with a variety of model and control materials.

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Inhibitors of Microsomal Prostaglandin E2 Synthase‐1 Enzyme as Emerging Anti‐Inflammatory Candidates
Authors: Singh Bahia Malkeet , Kumar Katare Yogesh , Silakari Om , Vyas Bhawna , Silakari Pragati
Published: January 2014

Cyclooxygenases (COX‐1 and COX‐2) catalyze the conversion of arachidonic acid (AA) into PGH2 that is further metabolized by terminal prostaglandin (PG) synthases into biologically active PGs, for example, prostaglandin E2 (PGE2), prostacyclin I2 (PGI2), thromboxane A2 (TXA2), prostaglandin D2 (PGD2), and prostaglandin F2 alpha (PGF2α). Among them, PGE2 is a widely distributed PG in the human body, and an important mediator of inflammatory processes. The successful modulation of this PG provides a beneficial strategy for the potential anti‐inflammatory therapy. For instance, nonsteroidal anti‐inflammatory agents (NSAIDs), both classical nonselective (cNSAIDs) and the selective COX‐2 inhibitors (coxibs) attenuate the generation of PGH2 from AA that in turn reduces the synthesis of PGE2 and modifies the inflammatory conditions. However, the long‐term use of these agents causes severe side effects due to the nonselective inhibition of other PGs, such as PGI2 and TXA2, etc. Microsomal prostaglandin E2 synthase‐1 (mPGES‐1), a downstream PG synthase, specifically catalyzes the biosynthesis of COX‐2‐derived PGE2 from PGH2, and describes itself as a valuable therapeutic target for the treatment of acute and chronic inflammatory disease conditions. Therefore, the small molecule inhibitors of mPGES‐1 would serve as a beneficial anti‐inflammatory therapy, with reduced side effects that are usually associated with the nonselective inhibition of PG biosynthesis.
BMI and the risk of colorectal adenoma in African‐Americans
Authors: Ashktorab Hassan , Paydar Mansour , Yazdi Shahla , Namin Hassan Hassanzadeh , Sanderson Andrew , Begum Rehana , Semati Mohammad , Etaati Firoozeh , Lee Edward , Brim Hassan , Zenebe Anteneh , Nunlee‐Bland Gail , Laiyemo Adeyinka O. , Nouraie Mehdi
Published: January 2014

Objectives

Obesity is associated with the activation of the molecular pathways that increase the risk of colorectal cancer. Increasing body mass index may accelerate the development of adenomatous polyps, the antecedent lesion of colorectal cancer. The aim of this study was to assess the BMI effect on the risk of colonic polyp and adenoma in African‐American.

Methods

The records of 923 patients who underwent colonoscopy were examined. Demographic and clinical data were collected before colonoscopy. Polyp and adenoma diagnosis were confirmed by pathology examinations.

Results

Overall, 43% of the patients were male, median age was 57 years and 77% had BMI ≥ 25.0 kg/m2. The frequency of colorectal polyps and adenomas were 61 and 35%, respectively. BMI ≥ 25.0 (OR = 1.61, 95% CI = 1.14‐2.26), smoking (OR = 1.61, 95% CI = 1.15‐2.26) and history of colon polyps (OR = 1.64, 95% CI = 1.09‐2.47) were associated with higher risk of colon polyp. BMI ≥ 25.0 (OR = 1.81, 95% CI = 1.24‐2.62), age (OR = 1.04, 95% CI = 1.02‐2.05 for each year), male gender (OR = 1.38, 95% CI = 1.02‐1.86), and smoking (OR = 1.73, 95% CI = 1.23‐2.42) were associated with higher risk of colon adenoma.

Conclusion

Male and overweight African‐Americans are at higher risk of colorectal adenoma. The findings of this study could be applied for risk stratification and modifying the colorectal cancer prevention including screening guideline in African Americans.
In vivo detection of polyomaviruses JCV and SV40 in mesenchymal stem cells from human umbilical cords
Authors: Comar Manola , Delbue Serena , Zanotta Nunzia , Valencic Erica , Piscianz Elisa , Del Savio Rossella , Tesser Alessandra , Tommasini Alberto , Ferrante Pasquale
Published: January 2014

Background

Multipotent stromal cells are present in the Wharton's jelly matrix (WJSC) of the umbilical cord and can be used as an allogeneic source of cells to treat immunological disorders. Recently it was demonstrated that adult bone marrow (BM)‐derived mesenchimal stromal cells (MSC) are susceptible to infection with viruses showing potential oncogenic properties, such as the polyomavirus JC (JCV). The aim of this study was to investigate the presence of human polyomaviruses (JCV, BK Virus‐BKV, SV40, and Merkel cell polyomavirus‐MCPyV) in WJSC, and explore the risk of infection.

Procedure

MSC samples from 35 umbilical cords were investigated by quantitative Real Time PCRs for the presence of DNA sequences of JCV, BKV, SV40, and MCPyV.

Results

JCV DNA was detected in 1/35 (2.8%) of MSC samples, while SV40 DNA was found in 3/35 (8.6%) of the examined samples. None of the samples showed sequences of BKV and MCPyV.

Conclusions

The present study demonstrates the in vivo ability of polyomaviruses to infect WJSC. Since the therapeutic approach with the WJSC has high potentiality and a more intensive use can be easily hypothesized, the need to develop consensus guidelines to detect rare viral infections in MSC is pressing. Pediatr Blood Cancer 2014; 61:1347–1349. © 2014 Wiley Periodicals, Inc.
Congenital dyserythropoietic anemia type I presenting as persistent pulmonary hypertension with pigeon chest deformity
Authors: El‐Sheikh Ayman A. , Hashem Hasan , Holman Carol , Vyas Yatin M.
Published: January 2014

Congenital dyserythropoietic anemia (CDA) type‐1 is a rare genetic disorder of ineffective erythropoiesis, which manifests in macrocytic anemia. We report a CDA1 patient who as a newborn presented with macrocytic anemia and persistent pulmonary hypertension of the newborn (PPHN) requiring mechanical ventilation. Post‐infancy, the patient developed acral dysmorphism and pectus excavatum the latter rarely found in CDA1. Patient is a compound heterozygote for a known maternal‐derived missense‐mutation (c.1796A > G/p.Asn589Ser) and a novel paternal‐derived deletion‐mutation (c.1104_1106del/Phe365del) in CDAN1. This report highlights the importance of recognizing PPHN as a presenting symptom of CDA1 and expands the repertoire of the accompanying mutations and axial skeletal malformations. Pediatr Blood Cancer 2014; 61:1460–1462. © 2014 Wiley Periodicals, Inc.
Effect of modification conditions of coal gangue on properties of natural rubber composites
Authors: Chen Jing , Xu Kui , Pan Rongkan , Peng Zheng , Ma Lin
Published: January 2014

The purpose of this work is to study the reinforcement effect of modified coal gangue (CG) on natural rubber (NR); carbon black (CB) was taken as reference filler. The addition of CG and CB to NR with the total filler loading fixed at 35 phr. The orthogonal experiment was employed to reveal the modification conditions on reinforcing properties. The results show that modification conditions such as weight ratio of coupling agent (CA), calcining temperature (CT), and calcining time (CM) affect the strengthening properties of CG, and CA is the most important factor influencing the tensile strength of NR, the order of influence can be expressed as CA > CT > CM. The optimum modification conditions are CT 800°C, CM 1 hr, and CA 2%. 300% modulus of NR composites filled with modified CG (17.5 phr)/CB (17.5phr) hybrid filler is similar to NR filled with CB alone at same filler loading, while elongation at break increases significantly for existent of CG. The effect of heat treatment and modification conditions of CG were tested by particle size distribution, scanning electron microscopy, Fourier transform infrared spectra, and X‐ray diffraction. The results show that the specific surface area of CG increased and hydroxyl group in crystal structure of CG removed under heat treatment. Dynamic mechanical analysis results show that the storage modulus and tan δ of CG filled NR composites are higher while Tg is less than that of CB, indicating the existence of a strong and stiff interface between filler and NR matrix. POLYM. COMPOS., 35:1911–1917, 2014. © 2014 Society of Plastics Engineers
Comparative Effectiveness of Linezolid and Vancomycin Among a National Veterans Affairs Cohort with Methicillin‐Resistant Staphylococcus aureus Pneumonia
Authors: Caffrey Aisling R. , Morrill Haley J. , Puzniak Laura A. , LaPlante Kerry L.
Published: January 2014

Study Objective

As variability in vancomycin dosing, susceptibility, and tolerability has driven the need to compare newer agents with vancomycin in real‐world clinical settings, we sought to quantify the effectiveness of linezolid compared with vancomycin on clinical outcomes for the treatment of methicillin‐resistant Staphylococcus aureus (MRSA) pneumonia.

Design

Retrospective cohort study.

Data Source

Veterans Health Administration national databases.

Patients

Adults admitted to Veterans Affairs hospitals between January 2002 and September 2010 with diagnosis codes for MRSA and pneumonia, plus initiation and receipt of at least 3 days of continuous intravenous vancomycin therapy (4943 patients) or intravenous or oral linezolid therapy (328 patients) while in the hospital.

Measurements and Main Results

Propensity score–adjusted Cox proportional hazards regression models quantified the effect of linezolid compared with vancomycin on time to 30‐day mortality (primary outcome), therapy change, hospital discharge, discharge from intensive care, intubation, 30‐day readmission, and 30‐day MRSA reinfection. In addition, a composite outcome of clinical success was defined as discharge from the hospital or intensive care unit by day 14 after treatment initiation, in the absence of death, therapy change, or intubation by day 14. Subgroup analyses were performed in a validated microbiology‐confirmed MRSA subgroup and clinical subgroup meeting clinical criteria for infection. Although a number of baseline variables differed significantly between the vancomycin and linezolid treatment groups, balance was achieved within propensity score quintiles. A significantly lower rate of therapy change was observed in the linezolid group (adjusted hazard ratio [HR] 0.68, 95% confidence interval [CI] 0.48–0.96). The clinical success rate was significantly higher among patients treated with linezolid (adjusted HR 1.25, 95% CI 1.07–1.47). Comparable findings were observed in the subgroup analyses.

Conclusion

Individual clinical outcomes were similar among patients treated for MRSA pneumonia with linezolid compared with vancomycin. A significantly higher rate of the composite outcome of clinical success was observed, however, among patients treated with linezolid compared with vancomycin.
Preparation and Performance of a BTF/DNB Cocrystal Explosive
Authors: Yang Zongwei , Wang Yuping , Zhou Junhong , Li Hongzhen , Huang Hui , Nie Fude
Published: January 2014

An energetic cocrystal containing benzotrifuroxan (BTF) and 1,3‐dinitrobenzene (DNB) in 1 : 1 molar ratio was prepared by slow evaporation of solvent. The structure of the cocrystal was determined by single crystal X‐ray diffraction (XRD). It belongs to the monoclinic crystal system with space group P21/c. The performance of the cocrystal was evaluated on the basis of thermolysis, impact sensitivity, and detonation properties. Differential scanning calorimetry (DSC) revealed that the cocrystal has a melting point of 130 °C, which is an increase of 38 °C compared to pure DNB; the decomposition temperature is similar to that of pure BTF. The cocrystal exhibits an impact height with 50 % ignition probability of 88 cm, suggesting a substantial reduction in impact sensitivity compared to pure BTF. Furthermore, the cocrystal is predicted to have a detonation velocity of about 7373 m s−1 and a detonation pressure of about 24 GPa, respectively, indicating excellent detonation performance.
On axionic dark matter in Type IIA string theory
Authors: Honecker G. , Staessens W.
Published: January 2014

We investigate viable scenarios with various axions in the context of supersymmetric field theory and in globally consistent D‐brane models. The Peccei‐Quinn symmetry is associated with an anomalous U(1) symmetry, which acquires mass at the string scale but remains as a perturbative global symmetry at low energies. The origin of the scalar Higgs‐axion potential from F‐, D‐ and soft breaking terms is derived, and two Standard Model examples of global intersecting D6‐brane models in Type II orientifolds are presented, which differ in the realisation of the Higgs sector and in the hidden sector, the latter of which is of particluar importance for the soft supersymmetry breaking terms.
Decoding the structural events in substrate‐gating mechanism of eukaryotic prolyl oligopeptidase using normal mode analysis and molecular dynamics simulations
Authors: Kaushik Swati , Etchebest Catherine , Sowdhamini Ramanathan
Published: January 2014

Prolyl oligopeptidase (POP) is a serine protease, unique for its ability to cleave various small oligopeptides shorter than 30 amino acids. POP is an important drug target since it is implicated in various neurological disorders. Although there is structural evidence that bacterial POPs undergo huge interdomain movements and acquire an “open” state in the substrate‐unbound form, hitherto, no crystal structure is available in the substrate‐unbound domain‐open form of eukaryotic POPs. Indeed, there is no difference between the substrate‐unbound/bound states of eukaryotic POPs. This raises unanswered questions about whether difference in the substrate access pathway exists between bacterial and eukaryotic POPs. Here, we have used normal mode analysis and molecular dynamics to unravel the mechanism of substrate entry in mammalian POPs, which has been debated until now. Motions observed using normal modes of porcine and bacterial POPs were analyzed and compared, augmented by molecular dynamics of these proteins. Identical to bacterial POPs, interdomain opening was found to be the possible pathway for the substrate‐gating in mammals as well. On the basis of our analyses and evidences, a mechanistic model of substrate entry in POPs has been proposed. Up‐down movement of N‐terminal hydrolase domain resulted in twisting motion of two domains, followed by the conformational changes of interdomain loop regions, which facilitate interdomain opening. Similar to bacterial POPs, an open form of porcine POP is also proposed with domain‐closing motion. This work has direct implications for the development of novel inhibitors of mammalian POPs to understand the etiology of various neurological diseases. Proteins 2014; 82:1428–1443. © 2014 Wiley Periodicals, Inc.
Tin – an unlikely ally for silicon field effect transistors?
Authors: Hussain Aftab M. , Fahad Hossain M. , Singh Nirpendra , Sevilla Galo A. Torres , Schwingenschlögl Udo , Hussain Muhammad M.
Published: January 2014

We explore the effectiveness of tin (Sn), by alloying it with silicon, to use SiSn as a channel material to extend the performance of silicon based complementary metal oxide semiconductors. Our density functional theory based simulation shows that incorporation of tin reduces the band gap of Si(Sn). We fabricated our device with SiSn channel material using a low cost and scalable thermal diffusion process of tin into silicon. Our high‐κ/metal gate based multi‐gate‐field‐effect‐transistors using SiSn as channel material show performance enhancement, which is in accordance with the theoretical analysis. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A model‐free and state‐cover testing scheme for semaphore‐based and shared‐memory concurrent programs
Authors: Hwang Gwan‐Hwan , Lin Che‐Sheng , Lee Teng‐Shuo , Wu‐Lee Chi
Published: January 2014

In this paper, we present a new framework for performing dynamic testing of semaphore‐based and shared‐memory concurrent programs. The proposed scheme only has to analyse the synchronization sequences (SYN‐sequences) that are collected during the dynamic testing of the concurrent program – static analysis of the syntax and semantics of the target concurrent program is unnecessary. A model checker is not needed to explore the feasible interleavings of the execution of the concurrent program. If the number of feasible SYN‐sequences of the tested concurrent program is finite, our scheme can perform dynamic testing of all the feasible SYN‐sequences. If the tested concurrent program has an infinite number of SYN‐sequences, state‐cover testing of the target program can be performed (if the execution states of the target concurrent program are finite). The implementation and experimental results obtained with real codes and some benchmark programs demonstrate the feasibility of the proposed scheme. Copyright © 2014 John Wiley & Sons, Ltd.
Fed-batch operation in special microtiter plates: a new method for screening under production conditions
Authors: Wilming Anja , Bähr Cornelia , Kamerke Claudia , Büchs Jochen
Published: January 2014

Batch and fed-batch operation result in completely different physiological conditions for cultivated microorganisms or cells. To close the gap between screening, which is hitherto exclusively performed in batch mode, and fed-batch production processes, a special microtiter plate was developed that allows screening in fed-batch mode. The fed-batch microtiter plate (FB-MTP) enables 44 parallel fed-batch experiments at small scale. A small channel filled with a hydrogel connects a reservoir well with a culture well. The nutrient compound diffuses from the reservoir well through the hydrogel into the culture well. Hence, the feed rate can easily be adjusted to the needs of the cultured microorganisms by changing the geometry of the hydrogel channel and the driving concentration gradient. Any desired compound including liquid nutrients like glycerol can be fed to the culture. In combination with an optical measuring device (BioLector), online monitoring of these 44 fed-batch cultures is possible. Two Escherichia coli strains and a Hansenula polymorpha strain were successfully cultivated in the new FB-MTP. As a positive impact of the fed-batch mode on the used strains, a fourfold increase in product formation was observed for E. coli. For H. polymorpha, the use of fed-batch mode resulted in a strong increase in product formation, whereas no measurable product formation was observed in batch mode. In conclusion, the newly developed fed-batch microtiter plate is a versatile, easy-to-use, disposable system to perform fed-batch cultivations at small scale. Screening cultures in high-throughput under online monitoring are possible similar to cultivations under production conditions.
MicroRNA sequence polymorphisms and the risk of different types of cancer
Authors: Hu Ye , Yu Chen-Yang , Wang Ji-Lin , Guan Jian , Chen Hao-Yan , Fang Jing-Yuan
Published: January 2014

MicroRNAs (miRNAs) participate in diverse biological pathways and may act as oncogenes or tumor suppressors. Single nucleotide polymorphisms (SNPs) in miRNAs (MirSNPs) might promote carcinogenesis by affecting miRNA function and/or maturation; however, the association between MirSNPs reported and cancer risk remain inconsistent. Here, we investigated the association between nine common MirSNPs and cancer risk using data from large scale case-control studies. Eight precursor-miRNA (pre-miRNA) SNPs (rs2043556/miR-605, rs3746444/miR-499a/b, rs4919510/miR-608, rs2910164/miR-146a, rs11614913/miR-196a2, rs895819/miR-27a, rs2292832/miR-149, rs6505162/miR-423) and one primary-miRNA (pri-miRNA) SNP (rs1834306/miR-100) were analyzed in 16399 cases and 21779 controls from seven published studies in eight common cancers. With a novel statistic, Cross phenotype meta-analysis (CPMA) of the association of MirSNPs with multiple phenotypes indicated rs2910164 C (P = 1.11E-03), rs2043556 C (P = 0.0165), rs6505162 C (P = 2.05E-03) and rs895819 (P = 0.0284) were associated with a significant overall risk of cancer. In conclusion, MirSNPs might affect an individual's susceptibility to various types of cancer.
Water-soluble polymers, solid polymer membranes, and coated fibres as smart sensory materials for the naked eye detection and quantification of TNT in aqueous media
Authors: Pablos Jesús L. , Trigo-López Miriam , Serna Felipe , García Félix C. , García José M.
Published: January 2014

The naked eye detection of TNT in aqueous environments using solid colorimetric sensory polymers and fibres, and in surfaces using water-soluble sensory polymers.
A visible light responsive rhodium and antimony-codoped SrTiO3 powdered photocatalyst loaded with an IrO2 cocatalyst for solar water splitting
Authors: Asai Rikako , Nemoto Hiroaki , Jia Qingxin , Saito Kenji , Iwase Akihide , Kudo Akihiko
Published: January 2014

IrO2-loaded SrTiO3 doped with rhodium and antimony synthesized by a conventional solid-state reaction splits water under visible light and simulated sunlight irradiation giving 0.1% of the apparent quantum yield at 420 nm.
Rare-earth carboxylates, [Ln2(iii)(μ3-OH)(C4H4O5)2(C4H2O4)]·2H2O [Ln = Ce, Pr and Nd]: synthesis, structure and properties
Authors: Sushrutha S. R. , Natarajan Srinivasan
Published: January 2014

Three new three-dimensional hybrid compounds, Ln2(μ3-OH)(C4H4O5)2(C4H2O4)]·2H2O, (Ln = Ce, Pr and Nd) (I2O1-type) exhibiting proton conductivity and multi-photon up-conversion behaviour have been described.
Micro- or nanorod and nanosphere structures derived from a series of phenyl-porphyrins
Authors: Harsha Vardhan Reddy M. , Al-Shammari Rusul M. , Al-Attar Nebras , Kennedy Eamonn , Rogers Luke , Lopez Sergio , Senge Mathias O. , Keyes Tia E. , Rice James H.
Published: January 2014

We examine here a series ofmeso-phenyl porphyrin micro- and nanostructures.
Ag2S/g-C3N4 composite photocatalysts for efficient Pt-free hydrogen production. The co-catalyst function of Ag/Ag2S formed by simultaneous photodeposition
Authors: Jiang Deli , Chen Linlin , Xie Jimin , Chen Min
Published: January 2014

Novel Ag2S/g-C3N4 composite photocatalysts with efficient Pt-free hydrogen evolution activity were fabricated. The Ag/Ag2S, formed by simultaneous photodeposition in the H2 evolution reaction, acts as an efficient co-catalyst for the g-C3N4.
Outdoor passive air monitoring of semi volatile organic compounds (SVOCs): a critical evaluation of performance and limitations of polyurethane foam (PUF) disks
Authors: Bohlin P. , Audy O. , Škrdlíková L. , Kukučka P. , Přibylová P. , Prokeš R. , Vojta Š. , Klánová J.
Published: January 2014

A polyurethane foam passive air sampler shows large inter-compound variability in sampling performance for semivolatile organic compounds in the outdoor environment.
High density, multi-range analog output Versa Module Europa board for control system applications
Authors: Singh Kundan , Das Ajit Lal
Published: January 2014

A new VMEDAC64, 12-bit 64 channel digital-to-analog converter, a Versa Module Europa (VME) module, features 64 analog voltage outputs with user selectable multiple ranges, has been developed for control system applications at Inter University Accelerator Centre. The FPGA (Field Programmable Gate Array) is the module's core, i.e., it implements the DAC control logic and complexity of VMEbus slave interface logic. The VMEbus slave interface and DAC control logic are completely designed and implemented on a single FPGA chip to achieve high density of 64 channels in a single width VME module and will reduce the module count in the control system applications, and hence will reduce the power consumption and cost of overall system. One of our early design goals was to develop the VME interface such that it can be easily integrated with the peripheral devices and satisfy the timing specifications of VME standard. The modular design of this module reduces the amount of time required to develop other custom modules for control system. The VME slave interface is written as a single component inside FPGA which will be used as a basic building block for any VMEbus interface project. The module offers multiple output voltage ranges depending upon the requirement. The output voltage range can be reduced or expanded by writing range selection bits in the control register. The module has programmable refresh rate and by default hold capacitors in the sample and hold circuit for each channel are charged periodically every 7.040 ms (i.e., update frequency 284 Hz). Each channel has software controlled output switch which disconnects analog output from the field. The modularity in the firmware design on FPGA makes the debugging very easy. On-board DC/DC converters are incorporated for isolated power supply for the analog section of the board.
Development and first experimental tests of Faraday cup array
Authors: Prokůpek J. , Kaufman J. , Margarone D. , Krůs M. , Velyhan A. , Krása J. , Burris-Mog T. , Busold S. , Deppert O. , Cowan T. E. , Korn G.
Published: January 2014

A new type of Faraday cup, capable of detecting high energy charged particles produced in a high intensity laser-matter interaction environment, has recently been developed and demonstrated as a real-time detector based on the time-of-flight technique. An array of these Faraday cups was designed and constructed to cover different observation angles with respect to the target normal direction. Thus, it allows reconstruction of the spatial distribution of ion current density in the subcritical plasma region and the ability to visualise its time evolution through time-of-flight measurements, which cannot be achieved with standard laser optical interferometry. This is a unique method for two-dimensional visualisation of ion currents from laser-generated plasmas. A technical description of the new type of Faraday cup is introduced along with an ad hoc data analysis procedure. Experimental results obtained during campaigns at the Petawatt High-Energy Laser for Heavy Ion Experiments (GSI, Darmstadt) and at the Prague Asterix Laser System (AS CR) are presented. Advantages and limitations of the used diagnostic system are discussed.
Development and assessment of a microwave void-fraction measurement system
Authors: Pochet S. , Teyssedou A. , Akyel C.
Published: January 2014

The proof of concept of a non-invasive reflection-type void measurement system using microwaves is developed. Before constructing the instrument, governing equations are used to perform numerical simulations of different electrical components (reflectometer, antenna, etc.). Design and preliminary calibrations are performed based on these simulations. The results are then used to manufacture a setup that is installed on a Plexiglas vertical tube containing known volumetric fractions of gas in water at atmospheric conditions. The amount of injected gas and water are accurately controlled and the response of the system is compared with the simulations which confirm the suitability of such a system to study two-phase water-air mixtures.
High performance organic field-effect transistors with ultra-thin HfO2 gate insulator deposited directly onto the organic semiconductor
Authors: Ono S. , Häusermann R. , Chiba D. , Shimamura K. , Ono T. , Batlogg B.
Published: January 2014

We have produced stable organic field-effect transistors (OFETs) with an ultra-thin HfO2 gate insulator deposited directly on top of rubrene single crystals by atomic layer deposition (ALD). We find that ALD is a gentle deposition process to grow thin films without damaging rubrene single crystals, as results these devices have a negligibly small threshold voltage and are very stable against gate-bias-stress, and the mobility exceeds 1 cm2/V s. Moreover, the devices show very little degradation even when kept in air for more than 2 months. These results demonstrate thin HfO2 layers deposited by ALD to be well suited as high capacitance gate dielectrics in OFETs operating at small gate voltage. In addition, the dielectric layer acts as an effective passivation layer to protect the organic semiconductor.
Molecular doping for control of gate bias stress in organic thin film transistors
Authors: Hein Moritz P. , Zakhidov Alexander A. , Lüssem Björn , Jankowski Jens , Tietze Max L. , Riede Moritz K. , Leo Karl
Published: January 2014

The key active devices of future organic electronic circuits are organic thin film transistors (OTFTs). Reliability of OTFTs remains one of the most challenging obstacles to be overcome for broad commercial applications. In particular, bias stress was identified as the key instability under operation for numerous OTFT devices and interfaces. Despite a multitude of experimental observations, a comprehensive mechanism describing this behavior is still missing. Furthermore, controlled methods to overcome these instabilities are so far lacking. Here, we present the approach to control and significantly alleviate the bias stress effect by using molecular doping at low concentrations. For pentacene and silicon oxide as gate oxide, we are able to reduce the time constant of degradation by three orders of magnitude. The effect of molecular doping on the bias stress behavior is explained in terms of the shift of Fermi Level and, thus, exponentially reduced proton generation at the pentacene/oxide interface.
Observation of enhanced carrier transport properties of Si ⟨100⟩-oriented whiskers under uniaxial strains
Authors: Zheng Kun , Shao Ruiwen , Deng Qingsong , Zhang Yuefei , Li Yujie , Han Xiaodong , Zhang Ze , Zou Jin
Published: January 2014

In this study, enhancements of the carrier transport properties of p-type ⟨100⟩-oriented Si whiskers are observed under uniaxial tensile and compressive strains. It has been found that over 400% enhancement of electrical conductivity is achieved under a 2% tensile strain, while a 2% compressive strain can only cause ∼80% conductivity enhancement. The enhancements are mainly attributed to the breaking of the degeneracy of the v2 and v1 valence bands induced a reduction of the hole effective mass. This study provides an important insight of how the carrier mobility variation caused by the strain impact on their transport properties.
Strain-induced fundamental optical transition in (In,Ga)As/GaP quantum dots
Authors: Robert C. , Nestoklon M. O. , Pereira da Silva K. , Pedesseau L. , Cornet C. , Alonso M. I. , Goñi A. R. , Turban P. , Jancu J.-M. , Even J. , Durand O.
Published: January 2014

The nature of the ground optical transition in an (In,Ga)As/GaP quantum dot is thoroughly investigated through a million atoms supercell tight-binding simulation. Precise quantum dot morphology is deduced from previously reported scanning-tunneling-microscopy images. The strain field is calculated with the valence force field method and has a strong influence on the confinement potentials, principally, for the conduction band states. Indeed, the wavefunction of the ground electron state is spatially confined in the GaP matrix, close to the dot apex, in a large tensile strain region, having mainly Xz character. Photoluminescence experiments under hydrostatic pressure strongly support the theoretical conclusions.
Wavelength specific excitation of gold nanoparticle thin-films
Authors: Lucas Thomas M. , James Kurtis T. , Beharic Jasmin , Moiseeva Evgeniya V. , Keynton Robert S. , O'Toole Martin G. , Harnett Cindy K.
Published: January 2014

Advances in microelectromechanical systems (MEMS) continue to empower researchers with the ability to sense and actuate at the micro scale. Thermally driven MEMS components are often used for their rapid response and ability to apply relatively high forces. However, thermally driven MEMS often have high power consumption and require physical wiring to the device. This work demonstrates a basis for designing light-powered MEMS with a wavelength specific response. This is accomplished by patterning surface regions with a thin film containing gold nanoparticles that are tuned to have an absorption peak at a particular wavelength. The heating behavior of these patterned surfaces is selected by the wavelength of laser directed at the sample. This method also eliminates the need for wires to power a device. The results demonstrate that gold nanoparticle films are effective wavelength-selective absorbers. This “hybrid” of infrared absorbent gold nanoparticles and MEMS fabrication technology has potential applications in light-actuated switches and other mechanical structures that must bend at specific regions. Deposition methods and surface chemistry will be integrated with three-dimensional MEMS structures in the next phase of this work. The long-term goal of this project is a system of light-powered microactuators for exploring cellular responses to mechanical stimuli, increasing our fundamental understanding of tissue response to everyday mechanical stresses at the molecular level.
Does Alicante Have the Longest Urban Geometric Illusion in the World?
Authors: Taylor Steve , Taylor Matthew
Published: January 2014

Interest in geometric illusions in architectural design was restimulated in the 1970s by the publication of a paper by Gregory and Heard on the Café Wall illusion. Illusory patterns have been used in urban design for centuries. This brief note identifies two further examples of urban illusions found in Alicante, Spain and suggests that they may represent currently the longest examples of urban geometric illusion in the world.
Depth Modulation of the Attentional Repulsion Effect
Authors: Chien Sung-En , Watanabe Katsumi
Published: January 2014

Shifts of attention can cause mislocalisation of visual objects. A brief cue that attracts attention can cause a shift in the perceived location of a subsequently presented visual object—specifically, moving it away from the focus of attention (attentional repulsion). In the present study we investigated whether depth would influence the magnitude of attentional repulsion by presenting peripheral visual cues in different depth planes from the target or fixation. In experiment 1 the results showed that the magnitude of the attentional repulsion was larger when the cue was presented at the depth plane farther away from the target and fixation. In experiment 2 we presented the fixation point in the same depth plane as the nearest cues and found larger repulsion effects when the cues were presented in depth planes farther away from the fixation. In experiment 3 no depth modulation was observed when the fixation was presented in the same depth plane with the farthest cues. Taken together, when the cues were presented in the depth plane farther away from the fixation, the magnitude of the attentional repulsion effect increased. It is speculated that the residual coarser spatial representation in the space farther from the fixation plane or the enhanced attentional process for the space closer than the fixation may be responsible for the larger attentional repulsion effect.
Visually Tracking and Localizing Expanding and Contracting Objects
Authors: Howe Piers D L , Holcombe Alex O , Lapierre Mark D , Cropper Simon J
Published: January 2014

The maintenance of attention on moving objects is required for cognition to reliably engage with the visual world. Theories of object tracking need to explain on which patterns of visual stimulation one can easily maintain attention and on which patterns one cannot. A previous study has shown that it is easier to track rigid objects than objects that expand and contract along their direction of motion, in a manner that resembles a substance pouring from one location to another (vanMarle and Scholl 2003 Psychological Science14 498–504). Here we investigate six possible explanations for this finding and find evidence supporting two of them. Our results show that, first, objects that expand and contract tend to overlap and crowd each other more, and this increases tracking difficulty. Second, expansion and contraction make it harder to localize objects, even when there is only a single target to attend to, and this may also increase tracking difficulty. Currently, there is no theory of object tracking that can account for the second finding.
Development of a TILLING resource in durum wheat for reverse- and forward-genetic analyses
Authors: Bovina R. , Brunazzi A. , Gasparini G. , Sestili F. , Palombieri S. , Botticella E. , Lafiandra D. , Mantovani P. , Massi A.
Published: January 2014

A durum wheat TILLING (targeting induced local lesions in genomes) population of 2601 M3 families was developed from cv. Svevo using ethyl methanesulfonate as a chemical mutagen. The entire M3 population was field-grown for phenotypic evaluations. Despite the polyploid nature of the wheat genome, a preliminarily phenotypic screening showed a high frequency of morphological alterations (~22%); specific phenotyping for seed morphology was undertaken. Furthermore, a reverse-genetics experiment was performed on DNA collected from M2 leaves for the homoeologous genes SBEIIa-A and SBEIIa-B involved in starch metabolism. One non-sense mutation for both genes was identified; specific crosses are planned in order to pyramid the two mutations.
Relationship between adiponectin and fertility in the female pig
Authors: Campos Danila B. , Albornoz Marcelo , Papa Paula C. , Palin Marie-France , Bordignon Vilceu , Murphy Bruce D.
Published: January 2014

Adiponectin isoforms may mediate different aspects of the pleiotropic function of the protein, including the reproductive process. We examined the pattern of circulating adiponectin and adiponectin system expression in fat and ovarian tissues of hyperfertile and subfertile sows. We demonstrated the presence of five different isoforms of adiponectin (90, 158, 180, 250 and >250 kDa) in the circulation and identified a subgroup of subfertile females that displayed reduced abundance of all adiponectin isoforms as well as a lack of the 250-kDa adiponectin isoform in both serum and follicular fluid. Subfertility in these animals was associated with fewer large follicles and corpora lutea in the ovaries, as well as lower concentrations of 17β-oestradiol in the follicular fluid of large follicles. In addition, subfertile females showed higher adiponectin mRNA in fat tissue and altered mRNA and protein expression of adiponectin and its receptors in the ovary. Changes in the abundance and pattern of circulating adiponectin isoforms have been associated with reproductive disorders in animals and humans, including polycystic ovarian syndrome (PCOS). Our findings suggest that the adiponectin system may play an important role in controlling ovarian function and influencing porcine fertility.
Decomposing the 𝐶*-algebras of groupoid extensions
Authors: Brown Jonathan , an Huef Astrid
Published: January 2014

We decompose the full and reducedC∗C^*-algebras of an extension of a groupoid by the circle into a direct sum of twisted groupoidC∗C^*-algebras.
Exchange-rate risk and UK-China trade: evidence from 47 industries
Authors: Bahmani-Oskooee Mohsen , Hegerty Scott , Zhang Ruixin
Published: January 2014

Purpose

– Recent years have seen a rapid expansion of studies that examine the effects of exchange-rate risk on bilateral exports and imports for specific industries. Since the underlying theory is ambiguous, each case must be studied individually. This paper considers British trade with China, for 47 types of product, over the period from 1978 to 2010. Consistent with the underlying theory, cointegration analysis shows that most industries register no effect due to volatility in the long run, while some trade flows are reduced and a handful are even increased. An analysis of industry characteristics suggests that while the type of good might play little role on an industry's specific results, a product's trade share does. This is the case for UK imports of Chinese goods, perhaps because large Chinese exporters are able to successfully hedge against exchange-rate risk. The paper aims to discuss these issues.

Design/methodology/approach

– The method is based on bounds testing approach to cointegration and error-correction modeling.

Findings

– The paper arrives at two key conclusions. First, as has been shown previously for other country pairs, most industries demonstrate no long-run response to exchange-rate volatility. A fraction of industries are affected, and most of these effects are negative.

Research limitations/implications

– This research pertains to the case of industry trade between the UK and China only.

Practical implications

– The paper identifies industries that are affected by exchange rate uncertainty.

Originality/value

– No study has looked at the impact of exchange rate uncertainty on the trade flows between China and the UK at commodity level.
A macro assessment of China effects on Malaysian exports and trade balances
Authors: Chan Tze-Haw , Hooi Lean Hooi , Hooy Chee-Wooi
Published: January 2014

Purpose

– This paper aims to focus on the impact of China's export expansion on Malaysian monthly trading with to her 12 major trading partners over the liberalization era.

Design/methodology/approach

– The analytical framework comprises of both the export and trade balance models. Unit root and cointegration tests with break and error correction modeling are employed in the analyses.

Findings

– Regime shifts are evident in the long run where structural break(s) found mostly coincides with the Asia crisis and China's accession into WTO. While the income effects are more apparent in most cases, the real exchanges are rather insignificant and incorrectly signed for Malaysian bilateral trading. Besides, the trade balance estimation is generally more consistent that the Chinese exports have exhibited complementary effects in the long-run, mainly for advanced export destination such as Australia, Germany, Japan, the UK and the USA. On the whole, there is insufficient evidence to support the “PRC competitive threat”.

Practical implications

– The empirical evidence disfavors currency devaluation for current account correction and reveals that the fear for China effect might be over-projected. Closer regional collaboration and trade integration between the two nations are well expected.

Originality/value

– The paper assesses the China's crowding out effect and magnitudes of Malaysian export and trade balance elasticities with model specifications that consider structural breaks. The paper also assesses the macro dimension of income and real exchanges effects.