bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of concentration of hexamethylene tetramine on the structural morphology and optical properties of ZnO microrods grown by low‐temperature solution approach
Authors: Mridha S. , Basak D. 
Published: May 2009

AbstractWe study the change in the structural morphology and optical properties of aqueous solution grown ZnO microrods on glass substrates with the change in the concentration of hexamethylene tetramine (HMT). The field emission scanning electron microscope images of the microrods grown for equimolar (1:1) ratio of Zn2+ salt and HMT exhibit the highest aspect ratio, 8.3, which decreases gradually, while the relative intensity of the (100) peak in the X‐ray diffractogram increases with increase in the HMT concentration. The change in the morphology from a perfect hexagonal to an oval‐shaped needle is experimentally supported by the high‐resolution transmission electron microscope results. A sharp and strong ultraviolet photoluminescence peak ensures good structural quality of the microrods for the molar ratios 1:1 and 1:3 above which the quality degrades. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gamma‐radiation effects on NaCl:Cu crystals
Authors: Cruz‐Zaragoza E. , Chernov V. , Meléndrez R. , Barboza‐Flores M. 
Published: May 2009

AbstractThe γ‐radiation effects on copper‐doped NaCl:Cu crystals were investigated. Single crystals exposed to gamma radiation from 0.001 kGy to 30 kGy at room temperature exhibited optical absorption bands attributed to Cu– (236 nm), Cu+ (255 nm) and F (463 nm) centers. The F and Cu absorption annealing bands were correlated to the thermoluminescence (TL) glow‐curve peak structure around 30–165 °C and 215–350 °C, respectively. The TL glow curves of samples doped with 0.04 mol% and 0.08 mol% of Cu+ ions showed a strong quenching effect for higher doping concentration. In addition, thermal bleaching of γ‐irradiated specimens confirmed the color centers and Cu‐doping participation on the TL process. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reliability issues of SiC power MOSFETs toward high junction temperature operation
Authors: Tanimoto Satoshi , Ohashi Hiromichi 
Published: May 2009

AbstractThere still remain a number of reliability problems to be resolved with regard to long‐term high junction temperature operation of SiC power devices because at present they simply follow Si‐based technology. In this paper, various reliability issues for power DMOS devices on 4H‐SiC operated at a junction temperature of more than 200 °C are extensively discussed in terms of five manifest problems and potential treats: (1) interlayer dielectric erosion, (2) Al spearing, (3) Ni2Si contact disappearance, (4) electrode delamination, and (5) gate time‐dependent dielectric breakdown. Preventive measures for these issues are proposed, including the use of a Ta/TaN barrier metal, a SiCH barrier dielectric, decarbonised Ni2Si and an ONO gate dielectric, and their effectiveness is experimentally verified. A viable device structure and fabrication process that successfully incorporate these measures are then presented. Finally, a storage life of more than 5380 hours at 300 °C is demonstrated for 1 × 1 mm24H‐SiC power DMOS devices incorporating selected countermeasures. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural elucidation of metabolites of ginkgolic acid in rat liver microsomes by ultra‐performance liquid chromatography/electrospray ionization tandem mass spectrometry and hydrogen/deuterium exchange
Authors: Liu Z. H. , Chen J. , Yu L. S. , Jiang H. D. , Yao T. W. , Zeng S. 
Published: May 2009

AbstractGinkgolic acids have been shown to possess allergenic as well as genotoxic and cytotoxic properties. The question arises whether the metabolism of ginkgolic acids in the liver could decrease or increase their toxicity. In this study, theinvitrometabolism of ginkgolic acid (15:1, GA), one component of ginkgo acids, was investigated as a model compound in Sprague‐Dawley rat liver microsomes. The metabolites were analyzed by ultra‐performance liquid chromatography coupled with photodiode array detector/negative‐ion electrospray ionization tandem mass spectrometry (UPLC‐PDA/ESI‐MS/MS) and hydrogen/deuterium (H/D) exchange. The result showed that the benzene ring remained unchanged and the oxidations occurred at the side alkyl chain in rat liver microsomes. At least eight metabolites were found. Among them, six phase I metabolites were tentatively identified. This study might be useful for the investigation of toxicological mechanism of ginkgolic acids. Copyright © 2009 John Wiley & Sons, Ltd.
Sequence and phosphorylation level determination of two donkey β‐caseins by mass spectrometry
Authors: Cunsolo Vincenzo , Cairone Elisa , Saletti Rosaria , Muccilli Vera , Foti Salvatore 
Published: May 2009

AbstractTwo coeluting components, with experimentally measured Mr values of 25529 and 24606 Da, were identified by reversed‐phase high‐performance liquid chromatography (RP‐HPLC) and mass spectrometric analysis in the dephosphorylated casein fraction of a milk sample collected from an individual donkey belonging to the Ragusano breed of the east of Sicily. By coupling enzymatic digestions, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) and RP‐HPLC/nano‐electrospray ionization tandem mass spectrometry (nESI‐MS/MS) analysis, the two proteins were identified as donkey β‐CNs and their sequences characterized completely, using the two known β‐CNs from mare as references. The two donkey β‐CNs, showing a mass difference of 923 Da, differ by the presence of the domain E27SITHINK34 in the full‐length component (Mr 25529 Da). In comparison with the mare's β‐CNs used as reference, they present nine amino acid substitutions: L→S37, R→H52, S→N81, P→V84, L→V91, R→Q203, P→L/I206, L→F210 and A→P219. Together, these substitutions account for the increase of 18 Da in the Mr of the donkey β‐CNs with respect to the counterparts from the mare. The molecular mass determination by ESI‐MS for the phosphorylated proteins showed that the full‐length component was composed of highly multi‐phosphorylated isoforms with five to seven phosphate groups. By analogy with the homologous mare's β‐CNs, the full‐length (226 amino acids) β‐CN was termed variant A, whereas the shorter (218 amino acids) β‐CN was termed variant AΔ5. Copyright © 2009 John Wiley & Sons, Ltd.
Mixtures of prior distributions for predictive Bayesian sample size calculations in clinical trials
Authors: Brutti Pierpaolo , De Santis Fulvio , Gubbiotti Stefania 
Published: May 2009

AbstractIn this paper we propose a predictive Bayesian approach to sample size determination (SSD) and re‐estimation in clinical trials, in the presence of multiple sources of prior information. The method we suggest is based on the use of mixtures of prior distributions for the unknown quantity of interest, typically a treatment effect or an effects‐difference. Methodologies are developed using normal models with mixtures of conjugate priors. In particular we extend the SSD analysis of Gajewski and Mayo (Statist. Med. 2006; 25:2554–2566) and the sample size re‐estimation technique of Wang (Biometrical J. 2006; 48(5):1–13). Copyright © 2009 John Wiley & Sons, Ltd.
Modelling heterogeneity in clustered count data with extra zeros using compound Poisson random effect
Authors: Ma Renjun , Hasan M. Tariqul , Sneddon Gary 
Published: May 2009

AbstractIn medical and health studies, heterogeneities in clustered count data have been traditionally modeled by positive random effects in Poisson mixed models; however, excessive zeros often occur in clustered medical and health count data. In this paper, we consider a three‐level random effects zero‐inflated Poisson model for health‐care utilization data where data are clustered by both subjects and families. To accommodate zero and positive components in the count response compatibly, we model the subject level random effects by a compound Poisson distribution. Our model displays a variance components decomposition which clearly reflects the hierarchical structure of clustered data. A quasi‐likelihood approach has been developed in the estimation of our model. We illustrate the method with analysis of the health‐care utilization data. The performance of our method is also evaluated through simulation studies. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and Spectral Studies of CdTe–Dendrimer Conjugates
Authors: Ghosh Srabanti , Saha Abhijit 
Published: May 2009

Abstract
In order to couple high cellular uptake and target specificity of dendrimer molecule with excellent optical properties of semiconductor nanoparticles, the interaction of cysteine-capped CdTe quantum dots with dendrimer was investigated through spectroscopic techniques. NH2-terminated dendrimer molecule quenched the photoluminescence of CdTe quantum dots. The binding constants and binding capacity were calculated, and the nature of binding was found to be noncovalent. Significant decrease in luminescence intensity of CdTe quantum dots owing to noncovalent binding with dendrimer limits further utilization of these nanoassemblies. Hence, an attempt is made, for the first time, to synthesize stable, highly luminescent, covalently linked CdTe–Dendrimer conjugate in aqueous medium using glutaric dialdehyde (G) linker. Conjugate has been characterized through Fourier transform infrared spectroscopy and transmission electron microscopy. In this strategy, photoluminescence quantum efficiency of CdTe quantum dots with narrow emission bandwidths remained unaffected after formation of the conjugate.
Fabrication of Uniform Au–Carbon Nanofiber by Two-Step Low Temperature Decomposition
Authors: Lee Myeongsoon , Hong Seong-Cheol , Kim Don 
Published: May 2009

Abstract
This paper presents a facile and efficient way to prepare carbon nanofibers ornamented with Au nanoparticles (Au/CNFs). Gold nanoparticles were first deposited in the channels of an anodized aluminum oxide (AAO) membrane by thermal decomposition of HAuCl4and then carbon nanofibers were produced in the same channels loaded with the Au nanoparticles by decomposition of sucrose at 230 °C. An electron microscopy study revealed that the carbon nanofibers, ~10 nm thick and 6 μm long, were decorated with Au nanoparticles with a diameter of 10 nm. This synthetic route can produce uniform Au nanoparticles on CNF surfaces without using any additional chemicals to modify the AAO channels or the CNF surfaces.
Will mobile learning change language learning?
Authors: Kukulska-Hulme Agnes 
Published: May 2009

AbstractThe use of mobile phones and other portable devices is beginning to have an impact on how learning takes place in many disciplines and contexts, including language learning. Learners who are not dependent on access to fixed computers can engage in activities that relate more closely to their current surroundings, sometimes crossing the border between formal and informal learning. This creates the potential for significant change in teaching and learning practices. Taking the broader field of mobile learning as the setting within which developments in mobile-assisted language learning may be understood, the paper argues that an emphasis on mobility can lead to new perspectives and practices. The paper offers reflections on what mobile learning has to offer and considers whether it is likely to change how languages are taught and learnt. ‘Mobile learning’ is not a stable concept; therefore its current interpretations need to be made explicit. Examples of current projects and practices show an affinity between mobile and games-based learning, and can further illuminate what is distinctive and worthwhile about mobile learning.
Training future language teachers to develop online tutors’ competence through reflective analysis
Authors: Guichon Nicolas 
Published: May 2009

AbstractThis article sets out to identify key competencies which language tutors need to develop in order to manage synchronous online teaching. In order to aptly monitor interactions with distant learners, it is proposed that three types of regulation pertaining to socio-affective, pedagogical and multimedia aspects are required. On the one hand, this research aims at specifying these competencies and, on the other hand, it seeks to identify the relevance of reflective analysis for professional development.The context of this study is a teacher training programme for Masters Degree students in teaching French as a foreign language that provides trainees with the opportunity of teaching online to intermediate-level students of French from a North American university via a desktop videoconferencing platform. This programme first endeavours to put trainees in a professional situation by getting them to prepare and administer sessions in order to confront them with the specific challenges of synchronous online tutoring. Second, it seeks to help them to gain insight into their own activity by developing critical thinking towards their own practice.The data elicited for this research derive from the tutor trainees’ interpretations of their own practice when confronted with the film of their own situated activity. The episodes chosen by the trainees to feed the self-confrontation process constitute significant units because by being told and commented upon, they elucidate how and to what extent competencies are built. Three discursive strategies have been identified and used to organise the content analysis of the data: description; expression of a difficulty; reflective review of the activity. The strategies used by trainees to verbalise their own activity can inform teacher educators about the constraints of the work situation and about the resources trainees need to deploy to face up to this unknown professional situation.Results indicate that trainees concentrate particularly on pedagogical aspects that distance and faulty technology have rendered complex. The encountered difficulties are equally distributed between a repertoire of competencies pertaining to language teaching and competencies more directly linked with online teaching. Finally, this study has enabled us to assess the potential of self-confrontation for teacher practice and leads us to propose directions for improving this training device.
Environmental and population externalities
Authors: JÖST FRANK , QUAAS MARTIN F. 
Published: May 2009

ABSTRACTWe analyze the external effects that arise in the decisions of firms on polluting emissions and in the decisions of parents on the number of births in an optimal control model with three stock variables representing population, economic capital, and pollution. We distinguish two different types of households, which represent opposite ends of a spectrum of potential familial structures: ‘dynastic households’, in which the family sticks together forever and ‘micro-households’, in which children leave their parent's household immediately after birth. We show that the decision of parents on the number of births involves an externality that is qualitatively different for both types of familial structure. Hence, population policy should be different, according to the type of household. A first best result may be obtained in the case of dynastic households if an appropriate tax on the household size is applied, or, in the case of micro-households, if an appropriate tax on children is applied.
Nutrient regime regulates complex transcriptional start site usage within a Pseudoalteromonas chitinase gene cluster
Authors: Delpin Marina W , Goodman Amanda E 
Published: May 2009

Abstract
The chitinase gene cluster of the marine bacterium Pseudoalteromonas sp. S91, chiABC, which produces the major chitinases of this sp., was transcribed as an operon and from each individual gene. chiA, chiB and chiC were found to possess multiple transcriptional start points (TSPs), the use of which was determined by the nutrient regime used for S91 growth. In minimal medium containing glutamate, chiA, chiB and chiC each used 3, 1 and 1 TSP, respectively. Upon the addition of the chitin monomer N-acetylglucosamine, the number of chiA TSPs was unaffected. However, chiB used an additional 4 TSPs, and chiC used four new TSPs excluding the TSP used in glutamate only. In addition, the cluster was transcribed as an operon from TSP A1 of chiA. All TSPs were potentially associated with either a σ70- or σ54-dependent promoter. Under the growth conditions used, no TSPs were detected for chiB or chiC in S91CX, a chiA transposon mutant. The transcription of the S91 chiABC gene cluster produced at least four polycistronic mRNAs. In addition, the occurrence of operon transcription of chiABC, and identification of an additional 12 putative TSPs within the gene cluster, gave an indication that each gene appeared to be transcribed from more than one promoter region upstream of each in-frame translation start codon. Questions arose regarding the reason for this complexity of transcription within the gene cluster, leading to a re-evaluation of the Chi protein domains. By bioinformatic review, ChiA, ChiB and ChiC were found to potentially possess additional putative domains.
Can the black box be cracked? The augmentation of microbial ecology by high-resolution, automated sensing technologies
Authors: Shade Ashley , Carey Cayelan C , Kara Emily , Bertilsson Stefan , McMahon Katherine D , Smith Matthew C 
Published: May 2009

Abstract
Automated sensing technologies, ‘ASTs,’ are tools that can monitor environmental or microbial-related variables at increasingly high temporal resolution. Microbial ecologists are poised to use AST data to couple microbial structure, function and associated environmental observations on temporal scales pertinent to microbial processes. In the context of aquatic microbiology, we discuss three applications of ASTs: windows on the microbial world, adaptive sampling and adaptive management. We challenge microbial ecologists to push AST potential in helping to reveal relationships between microbial structure and function.
Randomized, Double-blind, Placebo-controlled, Dose-response, and Preclinical Safety Study of Transforaminal Epidural Etanercept for the Treatment of Sciatica
Authors: Cohen Steven P. , Bogduk Nikolai , Dragovich Anthony , Buckenmaier Chester C. , Griffith Scott , Kurihara Connie , Raymond JoLynne , Richter Philip J. , Williams Necia , Yaksh Tony L. 
Published: May 2009

Background
Recent evidence implicates the inflammatory cytokine tumor necrosis factor as a major cause of radiculopathy. Yet, whereas open-label studies with systemically delivered tumor necrosis factor inhibitors have yielded positive results, a placebo-controlled study failed to demonstrate efficacy. One variable that may have contributed to poor outcomes is low drug levels at the site of nerve inflammation. To date, no studies have evaluated the efficacy or safety of epidurally administered anti-tumor necrosis factor agents.

Methods
A double-blind, placebo-controlled, dose-response study was conducted to evaluate an epidural tumor necrosis factor inhibitor. Twenty-four patients with subacute lumbosacral radiculopathy were randomly assigned to receive two transforaminal epidural injections of 2, 4, or 6 mg of entanercept 2 weeks apart in successive groups of eight. In each group, two patients received epidural saline. A parallel epidural canine safety study was conducted using the same injection doses and paradigm as in the clinical study.

Results
The animal and human safety studies revealed no behavioral, neurologic, or histologic evidence of drug-related toxicity. In the clinical arm, significant improvements in leg and back pain were collectively noted for the etanercept-treated patients, but not for the saline group, one month after treatment. One patient in the saline group (17%), six patients in the 2-mg group (100%), and four patients each in the 4-mg and 6-mg groups (67%) reported at least 50% reduction in leg pain and a positive global perceived effect one month after treatment. Six months after treatment, the beneficial effects persisted in all but one patient.

Conclusion
Epidural entanercept holds promise as a treatment for lumbosacral radiculopathy.
Localized Muscle Impedance Abnormalities in Amyotrophic Lateral Sclerosis
Authors: Tarulli Andrew W , Garmirian Lindsay P , Fogerson Patricia M , Rutkove Seward B 
Published: May 2009

Objectives:
To assess changes in electrical impedance myography (EIM) parameters in amyotrophic lateral sclerosis (ALS).

Methods:
Ten patients with ALS and a cohort of normal subjects underwent EIM testing of tibialis anterior. Montages using voltage and current electrodes placed at a distance (far) and in close proximity (near) were compared. The EIM parameters, resistance (R), reactance (X), and phase (θ) in the patients with ALS, were compared with normal values.

Results:
θ measured at 50 kHz using the near montage was most sensitive to the presence of ALS, with 9 of 10 patients with ALS having smaller θ values than the calculated lower limit of normal. θ using the far montage and X using both the near and far montages were also sensitive to disease, whereas R did not seem to be useful.

Conclusion:
EIM is sensitive to muscle abnormalities in ALS, with θ measured with near montages providing the best results.
What's in the Literature?
Authors: Harati Y 
Published: May 2009

Abstract

I am delighted to be the guest editor for this section of the Journal. Among the many publications related to neuromuscular diseases that appeared in the literature over the past few months, I have selected a few to review. The followings are my personal take of these articles with some added personal opinions on amyotrophic lateral sclerosis (ALS), stiff-person syndrome, complications of needle electromyography (EMG), hereditary neuropathies, and chronic inflammatory (immune-mediated) demyelinating polyneuropathy (CIDP). I hope that the readers of these pages find them interesting.
Necrotizing Enterocolitis: Risk Factor Analysis and Role of Gastric Residuals in Very Low Birth Weight Infants
Authors: Bertino Enrico , Giuliani Francesca , Prandi Giovanna , Coscia Alessandra , Martano Claudio , Fabris Claudio 
Published: May 2009

ABSTRACTObjective:Necrotizing enterocolitis (NEC) usually occurs in very low birth weight infants and is the most common gastrointestinal emergency in the neonatal intensive care unit. Inasmuch as NEC mortality and morbidity are extremely high, early diagnosis becomes essential. Increased gastric residuals are used to define NEC stage, but studies on qualitative and quantitative residual features as markers of NEC risk are still lacking. The primary goal of this analysis was evaluation of the role of gastric residuals in early identification of patients at risk for NEC. The secondary goal was investigation of NEC risk factors, besides prematurity and birth weight.Methods:In a case‐control study, NEC patients were matched with control infants by gestational age and birth weight. Feeding tolerance was assessed by maximum gastric residual volume, maximum residual as percentage of previous feeding, and residual appearance. Mortality and NEC risk factors were also evaluated.Results:In all, 844 very low birth weight infants were admitted to the neonatal intensive care unit during the study period, with an overall mortality before discharge of 14.6%. NEC frequency was 2%. Patent ductus arteriosus was significantly associated with NEC. Mean maximum residual from birth to NEC onset and maximum residual as percentage of the corresponding feed volume were significantly higher in patients than in control infants, as was the percentage of infants with hemorrhagic residuals.Conclusions:Gastric residuals are a marker of feeding intolerance, and bloody residuals seem to be the best predictor for NEC. For early detection of very low birth weight infants at risk for NEC, both gastric residual volumes and bloody residuals represent an early relevant marker.