bluuebunny/crossref_metadata_2025 huggingface dataset:
Complete Genome Sequence of the Giant Virus OBP and Comparative Genome Analysis of the Diverse ϕKZ-Related Phages
Authors: Cornelissen Anneleen , Hardies Stephen C. , Shaburova Olga V. , Krylov Victor N. , Mattheus Wesley , Kropinski Andrew M. , Lavigne Rob
Published: December 2011

The 283,757-bp double-stranded DNA genome of
Pseudomonas fluorescens
phage OBP shares a general genomic organization with
Pseudomonas aeruginosa
phage EL. Comparison of this genomic organization, assembled in syntenic genomic blocks interspersed with hyperplastic regions of the ϕKZ-related phages, supports the proposed division in the “EL-like viruses,” and the “phiKZ-like viruses” within a larger subfamily. Identification of putative early transcription promoters scattered throughout the hyperplastic regions explains several features of the ϕKZ-related genome organization (existence of genomic islands) and evolution (multi-inversion in hyperplastic regions). When hidden Markov modeling was used, typical conserved core genes could be identified, including the portal protein, the injection needle, and two polypeptides with respective similarity to the 3′-5′ exonuclease domain and the polymerase domain of the T4 DNA polymerase. While the N-terminal domains of the tail fiber module and peptidoglycan-degrading proteins are conserved, the observation of C-terminal catalytic domains typical for the different genera supports the further subdivision of the ϕKZ-related phages.
Antibody-Induced Conformational Changes in Herpes Simplex Virus Glycoprotein gD Reveal New Targets for Virus Neutralization
Authors: Lazear Eric , Whitbeck J. Charles , Ponce-de-Leon Manuel , Cairns Tina M. , Willis Sharon H. , Zuo Yi , Krummenacher Claude , Cohen Gary H. , Eisenberg Roselyn J.
Published: December 2011

As the receptor-binding protein of herpes simplex virus (HSV), gD plays an essential role in virus entry. In its native state, the last 56 amino acids of the ectodomain C terminus (C-term) occlude binding to its receptors, herpesvirus entry mediator (HVEM) and nectin-1. Although it is clear that movement of the C-term must occur to permit receptor binding, we believe that this conformational change is also a key event for triggering later steps leading to fusion. Specifically, gD mutants containing disulfide bonds that constrain the C-term are deficient in their ability to trigger fusion following receptor binding. In this report, we show that two newly made monoclonal antibodies (MAbs), MC2 and MC5, have virus-neutralizing activity but do not block binding of gD to either receptor. In contrast, all previously characterized neutralizing anti-gD MAbs block binding of gD to a receptor(s). Interestingly, instead of blocking receptor binding, MC2 significantly enhances the affinity of gD for both receptors. Several nonneutralizing MAbs (MC4, MC10, and MC14) also enhanced gD-receptor binding. While MC2 and MC5 recognized different epitopes on the core of gD, these nonneutralizing MAbs recognized the gD C-term. Both the neutralizing capacity and rate of neutralization of virus by MC2 are uniquely enhanced when MC2 is combined with MAb MC4, MC10, or MC14. We suggest that MC2 and MC5 prevent gD from performing a function that triggers later steps leading to fusion and that the epitope for MC2 is normally occluded by the C-term of the gD ectodomain.
Two MicroRNAs Encoded within the Bovine Herpesvirus 1 Latency-Related Gene Promote Cell Survival by Interacting with RIG-I and Stimulating NF-κB-Dependent Transcription and Beta Interferon Signaling Pathways
Authors: da Silva Leticia Frizzo , Jones Clinton
Published: December 2011

Sensory neurons latently infected with bovine herpesvirus 1 (BHV-1) abundantly express latency-related (LR) RNA (LR-RNA). Genetic evidence indicates that LR protein expression plays a role in the latency-reactivation cycle, because an LR mutant virus that contains three stop codons downstream of the first open reading frame (ORF2) does not reactivate from latency. The LR mutant virus induces higher levels of apoptotic neurons in trigeminal ganglia, and ORF2 interferes with apoptosis. Although ORF2 is important for the latency-reactivation cycle, other factors encoded by the LR gene are believed to play a supportive role. For example, two microRNAs (miRNAs) encoded within the LR gene are expressed in trigeminal ganglia of latently infected calves. These miRNAs interfere with bICP0 protein expression and productive infection in transient-transfection assays. In this report, we provide evidence that the two LR miRNAs cooperate with poly(I·C), interferon (IFN) regulatory factor 3 (IRF3), or IRF7 to stimulate beta interferon (IFN-β) promoter activity. Both miRNAs also stimulated IFN-β promoter activity and nuclear factor-kappa B (NF-κB)-dependent transcription when cotransfected with a plasmid expressing retinoic acid-inducible gene I (RIG-I). In the presence of RIG-I, the LR miRNAs enhanced survival of mouse neuroblastoma cells, which correlated with activation of the antiapoptosis cellular transcription factor, NF-κB. Immunoprecipitation assays demonstrated that both miRNAs stably interact with RIG-I, suggesting that this interaction directly stimulates the RIG-I signaling pathway. In summary, the results of these studies suggest that interactions between LR miRNAs and RIG-I promote the establishment and maintenance of latency by enhancing survival of infected neurons.
Accelerated Shedding of Prions following Damage to the Olfactory Epithelium
Authors: Bessen Richard A. , Wilham Jason M. , Lowe Diana , Watschke Christopher P. , Shearin Harold , Martinka Scott , Caughey Byron , Wiley James A.
Published: December 2011

In this study, we investigated the role of damage to the nasal mucosa in the shedding of prions into nasal samples as a pathway for prion transmission. Here, we demonstrate that prions can replicate to high levels in the olfactory sensory epithelium (OSE) in hamsters and that induction of apoptosis in olfactory receptor neurons (ORNs) in the OSE resulted in sloughing off of the OSE from nasal turbinates into the lumen of the nasal airway. In the absence of nasotoxic treatment, olfactory marker protein (OMP), which is specific for ORNs, was not detected in nasal lavage samples. However, after nasotoxic treatment that leads to apoptosis of ORNs, both OMP and prion proteins were present in nasal lavage samples. The cellular debris that was released from the OSE into the lumen of the nasal airway was positive for both OMP and the disease-specific isoform of the prion protein, PrP
Sc
. By using the real-time quaking-induced conversion assay to quantify prions, a 100- to 1,000-fold increase in prion seeding activity was observed in nasal lavage samples following nasotoxic treatment. Since neurons replicate prions to higher levels than other cell types and ORNs are the most environmentally exposed neurons, we propose that an increase in ORN apoptosis or damage to the nasal mucosa in a host with a preexisting prion infection of the OSE could lead to a substantial increase in the release of prion infectivity into nasal samples. This mechanism of prion shedding from the olfactory mucosa could contribute to prion transmission.
The importance of preparation for doctors' handovers in an acute medical assessment unit: a hierarchical task analysis
Authors: Raduma-Tomàs Michelle A , Flin Rhona , Yule Steven , Close Steven
Published: December 2011

Aim

To examine the ideal and actual processes of doctors' handovers in an acute medical assessment unit by means of a hierarchical task analysis (HTA) to identify any discrepancies between the ideal shift handover process as described by doctors, and the actual shift handover process as observed by the researcher.

Method

The HTA was constructed using information gathered from interviews (n=13) describing the activities doctors said they should ideally perform in preparation for the shift handover meeting, during the meeting and after the meeting has finished. Observations (n=32) were made pre handover, during handover and post handover to capture the actual handover process in the acute medical assessment unit. Furthermore, a focus group discussion was included to validate the researcher's observations of the actual handover process and to provide content validity to the constructed HTA of the ideal handover process.

Results

Findings as represented by the HTA diagram showed the complexity of the process. The diagram revealed critical tasks that should be completed at each phase of the handover process, but observations revealed that these were sometimes omitted, mainly due to work demands and time pressure. These omissions were most apparent in the pre-handover stage, resulting in interrupted, extended and/or delayed handover meetings.

Conclusion

The pre-handover phase is critical in providing a foundation for a thorough handover meeting and potentially helping doctors who have started a shift to prioritise patient care. These findings suggest that quality improvements for clinical handovers should include a designated time for preparation of care transfer information.
Acute stent occlusion due to heparin induced thrombocytopenia and thrombosis during carotid artery stenting: Figure 1
Authors: Stotts Grant , Skinner Chris , Code Cathy , Lawrie Garnett , Lesiuk Howard , Lum Cheemun
Published: December 2011

Heparin induced thrombocytopenia and thrombosis is a potential complication of any procedure following previous heparin exposure. A case is described of acute in-stent occlusion during carotid stenting due to heparin induced thrombocytopenia and thrombosis. Management options are also discussed.
The effects of exercise training on γ-butyrobetaine hydroxylase and novel organic cation transporter-2 gene expression in the rat
Authors: Broderick Tom L. , El Midaoui Adil , Chiasson Jean-Louis , Wang Donghao , Jankowski Marek , Gutkowska Jolanta
Published: December 2011

The concentration of carnitine in plasma is generally increased with exercise training, suggesting that either carnitine biosynthesis is stimulated or renal reabsorption of carnitine is enhanced, or both. Carnitine, an essential cofactor in the oxidation of fatty acids, is released into the plasma following hydroxylation by γ-butyrobetaine hydroxylase (BBH), the final enzyme in the biosynthetic pathway found primarily in the liver. The organic cation transporter (OCTN2), the carnitine transporter found in kidney, is important in the distribution of carnitine by facilitating its renal reabsorption from urine. In this study, we tested the hypothesis that exercise training increases gene and protein expression of BBH and OCTN2, resulting in enhanced plasma carnitine levels. Male Wistar rats were subjected to 2 daily exercise sessions of treadmill running, 5 days per week, for a 10-week period. The concentration of total carnitine in plasma was significantly increased in trained rats compared with sedentary rats. In trained rats, mRNA and protein expression of BBH were increased in liver, whereas only BBH mRNA expression was increased in kidney. Liver of trained rats demonstrated increased mRNA and protein expression of OCTN2 compared with sedentary rats. In kidney of trained rats, however, only an increase in mRNA expression of OCTN2 was observed. Our results suggest that the improved plasma carnitine status in the trained rat is associated with increased carnitine biosynthesis in liver and kidney. The observation that OCTN2 expression was increased in kidney suggests a potential role of the kidney in the reabsorption of carnitine from the urine.
Repetitive magnetic stimulation of the phrenic nerves for diaphragm conditioning: a normative study of feasibility and optimal settings
Authors: Adler Dan , Gottfried Stewart B. , Bautin Nathalie , Mirkovic Tomislav , Schmidt Matthieu , Raux Mathieu , Pavlovic Dragan , Similowski Thomas , Demoule Alexandre
Published: December 2011

Electrical stimulation can enhance muscle function. We applied repetitive cervical magnetic phrenic stimulation (rCMS) to induce diaphragm contractions in 7 healthy subjects (800 ms trains; transdiaphragmatic pressure (Pdi) measurements; tolerance ratings). Each rCMS train produced a sustained diaphragm contraction. Sixty-five percent of the maximal available output at 15 Hz proved the best compromise between Pdi and discomfort with nonfatiguing contractions. rCMS appears feasible and should be investigated for diaphragm conditioning in appropriate clinical populations.
Preserved muscle metaboreflex in chronic obstructive pulmonary disease
Authors: Sherman Megan F.B. , Road Jeremy D. , McKenzie Donald C. , Sheel A. William
Published: December 2011

The objective of this study was to measure the magnitude of the muscle metaboreflex in people with chronic obstructive pulmonary disease (COPD) compared with healthy controls and to assess the relationships between disease severity, exercise capacity, and the magnitude of the muscle metaboreflex. Nine people with mild-to-severe COPD and 11 age- and gender-matched healthy controls performed isometric handgrip exercise (IHG), followed by postexercise circulatory occlusion (PECO) while hemodynamic changes were measured. Continuous measures of heart rate, arterial pressure, leg blood flow, leg vascular resistance, and total peripheral resistance were obtained. Participants then performed a cycle test to exhaustion. Heart rate, blood pressure, and blood flow responses during IHG and PECO were similar between the COPD group and healthy controls (p > 0.05). There was no association between disease severity or exercise capacity and the magnitude of the muscle metaboreflex. We observed a preserved muscle metaboreflex in mild-to-severe COPD, suggesting the metaboreflex is not a contributing factor to the development of exercise intolerance in this population.
The effect of branched chain amino acids on psychomotor performance during treadmill exercise of changing intensity simulating a soccer game
Authors: Wiśnik Piotr , Chmura Jan , Ziemba Andrzej Wojciech , Mikulski Tomasz , Nazar Krystyna
Published: December 2011

The present study was designed to determine changes in the multiple-choice reaction time (MRT) during treadmill running simulating locomotor activity during a soccer game and to examine the effect of branched chain amino acids (BCAA) ingestion on psychomotor performance during the effort. Ten male soccer players were submitted to BCAA and placebo trials at 1-week intervals in a randomized order. BCAA (7 g) or placebo were given 1 h before exercise in a double blind manner. The running test consisted of two 45 min exercise bouts separated by a 15-min passive rest period and the whole test ended with 20-min active recovery. Running–walking speed changed from 0 to 6.4 m·s–1 according to the time-motion analysis of soccer match. During the test, blood samples were taken for lactate, glucose, free fatty acid, and catecholamine determination. Following placebo treatment, MRT shortened from 320 ± 18 to 271 ± 11 ms (p < 0.001) during the first exercise bout then it increased during the resting break to 303 ± 138 ms (p < 0.05). During the second bout, MRT decreased to 280 ± 13 ms (p < 0.001). During active recovery, further shortening of MRT was noted. During BCAA trial, MRT was shorter than during placebo trial by ~10% (p < 0.05) before and during exercise. No significant differences were found between BCAA and placebo trials in biochemical indices. It is concluded that BCAA supplementation might be recommended in sport activities that change in intensity and require quick responses to external signals (e.g., soccer and other team games).
Is peak oxygen uptake a determinant of moderate-duration self-paced exercise performance in the heat?
Authors: Schlader Zachary J. , Stannard Stephen R. , Mündel Toby
Published: December 2011

This study aimed to identify whether reductions in peak oxygen uptake (VO2peak) dictate performance outcomes during 30 min of self-paced exercise in the heat, which is expected to induce minimal hyperthermia. On 4 occasions, 11 male subjects completed peak and self-paced exercise in both hot (HOT, 40.2 ± 0.3 °C) and moderate (MOD; 20.4 ± 0.7 °C) conditions. During peak exercise, submaximal oxygen uptake (VO2) was ∼8% higher in HOT, but VO2peak (MOD, 4.64 ± 0.83 L·min–1; HOT, 4.54 ± 0.77 L·min–1) and peak cardiac output (Qpeak) were similar. Self-paced exercise performance was reduced by ∼21% in HOT. VO2 was similar through 15 min, but lower in HOT thereafter. Relative to MOD, this represented a higher and lower %VO2peak during the initial and latter stages. Cardiac output was similar in both trials (MOD, 31.6 ± 6.6 L·min–1; HOT, 30.1 ± 6.0 L·min–1), representing a similar percentage of Qpeak throughout. Rectal temperature was similar in both conditions until 30 min (MOD, 38.5 ± 0.3 °C; HOT, 38.7 ± 0.3 °C), while skin temperature was higher throughout in HOT (mean: MOD, 32.4 ± 1.1 °C; HOT, 37.3 ± 0.4 °C). Perceived exertion rose similarly in both conditions, while thermal discomfort was higher in HOT. These data indicate that when only skin temperature is elevated, reductions in exercise performance during moderate-duration self-paced exercise are not associated with changes in VO2peak. Rather, increases in VO2 at a given submaximal external workload and (or) thermal discomfort appear to play a larger role.
Exercise metabolism during moderate-intensity exercise in children with cystic fibrosis following heavy-intensity exercise
Authors: Stevens Daniel , Oades Patrick J. , Armstrong Neil , Williams Craig A.
Published: December 2011

Muscle metabolism is increased following exercise in healthy individuals, affecting exercise metabolism during subsequent physical work. We hypothesized that following heavy-intensity exercise (HIE), disease factors in children with cystic fibrosis (CF) would further exacerbate exercise metabolism and perceived exertion during subsequent exercise. Nineteen children with CF (age, 13.4 ± 3.1 years; 10 female) and 19 healthy controls (age, 13.8 ± 3.5 years; 10 female) performed 10 bouts of HIE interspersed with 1 min of recovery between each bout. Three minutes later participants completed a 10-min moderate-intensity exercise (MIE) test (test 1). The MIE test was subsequently repeated 1 h (test 2) and 24 h (test 3) later. Each MIE test was identical and participants exercised at individualized work rates, calibrated by an initial graded maximal cardiopulmonary exercise test, while metabolic and perceived exertion measurements were taken. Following HIE, mixed-model ANOVAs showed a significant difference in oxygen uptake (VO2) and rating of perceived exertion (RPE) between the 2 groups across the MIE tests (p < 0.01). In controls, VO2 (L·min–1) and RPE decreased significantly from test 1 to test 2 (p < 0.01) and test 2 to test 3 (p < 0.05). However, in children with CF, VO2 (L·min–1) increased significantly from test 1 to test 2 (p < 0.01), while RPE did not differ, both VO2 and RPE decreased significantly from test 2 to test 3 (p < 0.01). In conclusion, following HIE the metabolic and perceptual responses to MIE in both groups decreased 24 h later during test 3. These data show that children with mild-to-moderate CF have the capability to perform HIE and 24 h allows sufficient time for recovery.
Effects of a daily mixed nutritional supplement on physical performance, body composition, and circulating anabolic hormones during 8 weeks of arduous military training
Authors: Fortes Matthew B. , Diment Bethany C. , Greeves Julie P. , Casey Anna , Izard Rachel , Walsh Neil P.
Published: December 2011

The aim of this work was to investigate the effect of a daily mixed nutritional supplement upon body composition, physical performance, and circulating anabolic hormones in soldiers undergoing arduous training. Thirty males received either a habitual diet alone (CON, n = 15) or with the addition of a daily mixed supplement (SUP, n = 15) of ∼5.1 MJ·d–1 during 8 weeks of training. Body composition (DEXA), maximal dynamic lift strength (MDLS), and vertical jump (VJ) were assessed, and resting blood samples were collected before and after training. Blood analysis included insulin-like growth factors (IGF-1, IGF BP-1, and IGF BP-3), testosterone, and cortisol. There were no group differences at baseline. Body mass loss (mean ± SD) (CON 5.0 ± 2.3, SUP 1.6 ± 1.5 kg), lean mass loss (CON 2.0 ± 1.5, SUP 0.7 ± 1.5 kg), and fat mass loss (CON 3.0 ± 1.6, SUP 0.9 ± 1.8 kg) were significantly blunted by SUP. CON experienced significant decrements in MDLS (14%), VJ (10%), and explosive leg power (11%) that were prevented by SUP. Military training significantly reduced circulating IGF-1 (28%), testosterone (19%), and the testosterone:cortisol ratio (24%) with no effect of SUP. Circulating IGF BP-1 concentration and cortisol remained unchanged throughout, although SUP abolished the significant decrease in circulating IGF BP-3 (20%) on CON. In conclusion, a daily mixed nutritional supplement attenuated decreases in body mass and lean mass and prevented the decrease in physical performance during an arduous military training program.
Incorporating porosity-dependent hysteretic water retention behavior into a new constitutive model of unsaturated soils
Authors: Morvan M. , Wong H. , Branque D.
Published: December 2011

A new unsaturated soil model was recently developed at Ecole Nationale des Travaux Publics de l’Etat (ENTPE), based on the concept of bounding surface plasticity. The first version of this model (by Morvan et al. in 2010 ) only required 12 parameters for its definition, and yet can simulate a few behaviors typically observed on unsaturated fine sands, which more classical models fail to reproduce. These include post-peak softening, change from contractant to dilatant behavior during shearing, and the smooth transition from elastic to elastoplastic behavior upon yielding. Subsequent to this first publication, additional mechanisms have been introduced in the model previously developed. Among them, the hysteretic phenomenon during cyclic variations of suction and water content, as well as the effects of porosity change on water retention characteristics, are now taken into consideration. To this end, the water content is introduced as an independent generalized strain variable, which is no longer uniquely linked to suction. Thanks to these developments, the model can now account for the bilateral couplings between hydraulic and mechanical quantities, with good precision under very general loading conditions. In the present paper, these new developments are presented in detail, and the experimental basis of this construction is discussed. The model is then validated using existing experimental data on kaolin, by considering two stress paths. The first stress path consists of a single cycle of wetting followed by drying at constant isotropic stress. The second, more complex loading path involves simultaneous variations of suction and isotropic compression or decompression. The results confirm overall the satisfactory performance of the model. The main conclusions are then summarized in the last section, including perspectives for future developments.
How multi-scale approaches can benefit the design of cellular rockfall protection structures
Authors: Bourrier F. , Lambert S. , Heymann A. , Gotteland P. , Nicot F.
Published: December 2011

Cellular structures are efficient technological solutions for rockfall protection. A multi-scale approach is used to develop a cellular rockfall protection structure model for engineering purposes. The macroscopic structure is composed of mesoscale individual layers made up of rocky particles contained in wire netting cages, fine granular material, and a reinforced embankment. Simple constitutive models were developed for the different mesoscale layers of the structure. Information is gathered from experiments at the layer scale to calibrate the parameters of the constitutive models. The capacities of the model are evaluated by comparisons between simulations and impact experiments on small structures. Despite quantitative differences, the comparative analysis highlights that the structure model can account for the main physical mechanisms occurring during the impact on sandwich structures. This analysis also emphasizes the model’s applicability for engineering purposes.
STATE COMPLEXITY OF CODE OPERATORS
Authors: PRIBAVKINA ELENA , RODARO EMANUELE
Published: December 2011

We consider five operators on a regular language. Each of them is a tool for constructing a code (respectively prefix, suffix, bifix, infix) and a hypercode out of a given regular language. We give the precise values of the (deterministic) state complexity of these operators: over a constant-size alphabet for the first four of them and over a quadratic-size alphabet for the hypercode operator.
TORSION BOUNDS FROM CP VIOLATION α2-DYNAMO IN AXION–PHOTON COSMIC PLASMA
Authors: GARCIA DE ANDRADE L. C.
Published: December 2011

Years ago Mohanty and Sarkar [Phys. Lett. B433, 424 (1998)] have placed bounds on torsion mass from K meson physics. In this paper, associating torsion to axions a la Campanelli et al. [Phys. Rev. D72, 123001 (2005)], it is shown that it is possible to place limits on spacetime torsion by considering an efficient α2-dynamo CP violation term. Therefore instead of Kostelecky et al. [Phys. Rev. Lett.100, 111102 (2008)] torsion bounds from Lorentz violation, here torsion bounds are obtained from CP violation through dynamo magnetic field amplification. It is also shown that oscillating photon–axion frequency peak is reduced to 10-7 Hz due to torsion mass (or Planck mass when torsion does not propagate) contribution to the photon–axion–torsion action. Though torsion does not couple to electromagnetic fields at classical level, it does at the quantum level. Recently, Garcia de Andrade [Phys. Lett. B468, 28 (2011)] has shown that the photon sector of Lorentz violation (LV) Lagrangian leads to linear nonstandard Maxwell equations where the magnetic field decays slower giving rise to a seed for galactic dynamos. Torsion constraints of the order of K0≈10-42 GeV can be obtained which are more stringent than the value obtained by Kostelecky et al. A lower bound for the existence of galactic dynamos is obtained for torsion as K0≈10-37 GeV .
ELECTRODYNAMICS IN A BACKGROUND CHIRAL FIELD
Authors: BRANDT F. T. , MCKEON D. G. C. , PATRUSHEV A.
Published: December 2011

We consider the one-loop effective action in four-dimensional Euclidean space for a background chiral field coupled to a spinor field. It proves possible to find an exact expression for this action if the mass m of the spinor vanishes. If m does not vanish, one can make a perturbative expansion in powers of the axial field that contributes to the chiral field, while treating the contribution of the vector field exactly when it is a constant. The analogous problem in two dimensions is also discussed.
Au/TiO2 NANOTUBES FOR SELECTIVE DETECTION OF DOPAMINE
Authors: ARAVIND S. S. JYOTHIRMAYEE , SRINIVASAN SATHISH KUMAR , RAMAPRABHU SUNDARA
Published: December 2011

A novel biosensor for dopamine (DA) detection was fabricated using TiO2 nanotube and Au/TiO2 nanotube films on glassy carbon electrode (GCE). The Au/TiO2 nanotubes on electrode showed better electrocatalytic activity towards the detection of DA which was attributed to its excellent electron conductive network. The biosensor elicited sensitivity of 22 nA/μM with a linearity of detection localized in the concentration range from 5–120 μM with correlation coefficient of 0.99. The detection limit of DA for the Au/TiO2 nanotube biosensor was found to be ~3 μM (S/N = 3). In addition, the fabricated sensor showed good anti-interference capability towards biological compounds such as ascorbic acid and uric acid. In conclusion, Au/TiO2 nanotube biosensor exhibits excellent catalytic activity, selectivity and simplicity for the detection of dopamine.
LOW TEMPERATURE SYNTHESIS AND OPTICAL PROPERTIES OF (Cu, Cr, Fe)Al2O4 NANOCRYSTALLINE SPINEL MATERIALS
Authors: YADAV T. P. , SINGH DEVINDER , MUKHOPADHYAY N. K. , SHAZ M. A. , TIWARI R. S. , SRIVASTAVA O. N.
Published: December 2011

In the present investigation, ( Cu, Cr, Fe ) Al 2O4 spinel was synthesized from decagonal quasicrystalline precursor using mechanical milling followed by air annealing. The optimum annealing temperature and time were found to be 600°C and 60 h respectively. The evolution of the spinel structure started upon air annealing at 600°C from the B2 phase formed due to milling of quasicrystalline phase for 40 h. The relevant optical property of mechanically milled and air annealed samples prepared at different temperatures (400°C, 500°C and 600°C) were evaluated by photoluminescence technique. These studies suggested the presence of emission characteristics in blue region i.e. at 430 nm.
NANOMECHANICAL CHARACTERIZATION OF MULTIFERROIC THIN FILMS FOR MICRO-ELECTROMECHANICAL SYSTEMS
Authors: PRASHANTHI K. , MANDAL M. , DUTTAGUPTA S. P. , RAO V. RAMGOPAL , PANT P. , DHALE K. , PALKAR V. R.
Published: December 2011

In this paper, the elastic properties of Dy modified BiFeO3 (BDFO) multiferroic films deposited on Si substrate are reported for the first time. The mechanical properties are extracted using nanoindentation technique. The Young's modulus and hardness of the BDFO films are found to be 140 ± 3 GPa and 7.5 ± 0.3 GPa respectively. In this study the properties in the region of penetration depth up to 20% of BDFO film thickness, are found out. For these indentation depths, Young's modulus and hardness are almost constant indicating that substrate effects are not significant. It is also confirmed that neither cracks, nor pile-ups can be observed for indentation loads up to 10 mN. However, at higher indentation loads (>10 mN), bulging and spallation are observed suggesting delamination and buckling of the film. The mechanical properties of BDFO films are similar to that reported for lead zirconate titanate (PZT), while offering many novel properties. This report is accordingly expected to facilitate the design of BDFO-based micro-electromechanical systems devices.
STUDY OF STRUCTURAL AND MAGNETIC PROPERTIES OF Co-DOPED In2O3 NANOPARTICLES
Authors: PRAKASH RAM , SONG JUNG IL , KUMAR SHALENDRA , LEE CHAN GYU
Published: December 2011

In the present work, we have prepared Co doped In2O3 nanoparticles using co-precipitation method. The prepared nanoparticles were characterized by the X-ray diffraction, scanning electron microscopy and dc magnetization hysteresis loop measurements. From the X-ray diffraction analysis it observed that all sample exhibits single phase polycrystalline nature. All the diffraction lines correspond to the bixbyite cubic structure. The full width half maximum (FWHM) calculated from XRD pattern has been found to decrease with increase in the Co contents, indicating that particle size decreases with increase in the Co concentration. FE–SEM micrograph reflects the nanocrystalline behavior of all the samples and shows that doping of Co ions hinders growth of the particles. DC magnetization measurements reveal that Co -DOPED In2O3 samples exhibits room temperature ferromagnetism.
FABRICATION OF NANOSTRUCTURES USING POROUS ANODIC ALUMINA TEMPLATE
Authors: SASIKALA N. T. , BOOMINATHASELLARAJAN S. , RAGHUPATHY BALA PRAVEEN CHAKKRAVARTHY
Published: December 2011

Nanoporous alumina template was fabricated in dilute oxalic acid solution using a two step anodization process at voltage range of ~34 V. This was used as a template to form nanopillar matrices of copper by metal evaporation and direct deposition. Heat treatment of the copper nanopillars resulted in copper oxide ordered nanostructures which were characterized using electron microscopy. When these nanostructures were used as an electrochemical sensor for quantitative analysis of glucose in aqueous solutions, the electrodes modified with nanopillars showed a high degree of sensitivity compared to flat electrodes.
AGGREGATION BEHAVIOR OF IRON OXIDE NANOPARTICLES MEASURED BY SQUID MAGNETOMETRY
Authors: GUPTA MOHINI , SHARMA MANISH
Published: December 2011

The aggregation behavior of superparamagnetic iron oxide nanoparticles in an aqueous medium has been studied using SQUID magnetometry and XRD analysis. Iron oxide nanoparticles were synthesized by the coprecipitation method using iron salt and sodium hydroxide as precursors. The reactions were initially carried out at high temperature with different concentrations of iron salt. The synthesized nanoparticles were then collected for subsequent bio-functionalization. Structural characterizations were done using XRD and TEM measurements and show that the particles are magnetite (cubic spinel structure) with an average size of 9.5 nm. Magnetic measurements done using SQUID predict a magnetic particle size of 7.75 nm, which suggests a "magnetically dead layer" is present on the surface.
STRUCTURAL, OPTICAL, AND MAGNETIC PROPERTIES OF Gd-DOPED ZnO NANORODS BY A NOVEL AQUEOUS SOLUTION METHOD
Authors: PANIGRAHY BHARATI , ASLAM M. , MISRA D. S. , BAHADUR D.
Published: December 2011

In this paper, we demonstrate a simple facile aqueous chemical route to prepare large scale Gd doped ZnO nanorod at a temperature of 95°C. X-ray diffraction pattern confirms the wurtzite phase of Gd -doped ZnO nanorods having intense (002) peak with a peak shift towards lower angle. The UV emission intensity decreases by two orders of magnitude and blue-orange broad-band emission emanates from the defects, increases slightly by doping Gd ion in ZnO . Localized SAED patterns taken using nanoprobe size reveals that the nanorods are single crystals grown along c-axis [0001] direction. A systematic evalution of enhancement in ferromagnetism (M = 0.07 × 10-2 emu/g to 1.4 × 10-2 emu/g) indicates incorporation of Gd ions into the Zn lattice sites.
FIRST-PRINCIPLES INVESTIGATION INTO FERROMAGNETISM IN C-DOPED ZINC OXIDE CLUSTERS (ZnO)n; N = 1 – 12
Authors: SHARMA HITESH , SINGH RANBER
Published: December 2011

We report the first-principle calculations of ferromagnetism in C -doped ZnO clusters. The carbon impurities in ZnO clusters are doped at substitutional O or Zn sites and at interstitial sites and the total energy calculations suggest C at O site is more stable than that at Zn site. The substitutional C impurity is found more favorable than interstitial C impurity in these clusters. The ZnC region is mainly responsible for the observed ferromagnetism in ZnO:C systems. The average magnetic moment of Zn n O n–m C m clusters is found to be 2 μB/ C for n, m < 7. For n, m > 6 the magnetic moment decreases below 2 μB/ C . The magnetic moment in ( ZnO )n C i; i = 1 – 2 is found to be 0.1–2.0 μB/ C . The combination of substitutional and interstitial C impurities in ZnO clusters leads to magnetic moment of 0.4–1.0 μB/ C .
LASER INDUCED SEMICONDUCTOR–METAL TRANSITION IN A SEMIMAGNETIC QUANTUM WELL
Authors: NITHIANANTHI P. , JAYAKUMAR K.
Published: December 2011

The effect of laser and magnetic field on the semiconductor–metal transition in a Cd 1-x2 Mn x2 Te / Cd 1-x1 Mn x1 Te / Cd 1-x2 Mn x2 Te quantum well has been investigated using variational principle in effective mass approximation for smaller Mn composition. The effect of non parabolicity of the conduction band has been included in our calculation. The results are presented and discussed.
LOW TEMPERATURE SOLUTION PROCESS FOR FABRICATION OF ELECTRODES ON FLEXIBLE SUBSTRATE USING GOLD NANOPARTICLES
Authors: GUPTA ASHISH , MANDAL SAUMEN , KATIYAR MONICA , MOHAPATRA YASHOWANTA N.
Published: December 2011

Inkjet printing technology has emerged as major contender for large area electronics. The major challenge for this technology is the development of suitable conductive ink to obtain high quality patterns with desired electrical conductivity comparable to metals. The conductive ink should have good film formability on the flexible substrate as well as lower annealing temperature compatible with plastic substrates. Gold nano particle (AuNP) is the material of choice due to its very low sintering temperature in addition to excellent electrical property and resistance to corrosion. We have synthesized the butanethiol encapsulated Au-NP by the Brust method. We demonstrate a sintering temperature as low as 150°C for butanethiol capped gold nanoparticles of size less than 2 nm. The conductive gold films obtained after transformation have been investigated using four point probe method to measure sheet resistance as a function of process time. We show that the electrical properties degrade as annealing time increases. The reason for changes in electrical property has been investigated using SEM, TEM and XRD. The decrease in conductivity is traced to the formation of large micron sized gold crystallites on the film surface at temperatures as low as 160°C.
AN ORGANIC FIELD EFFECT TRANSISTORS-BASED SENSING PLATFORM FOR ENVIRONMENTAL/SECURITY APPLICATIONS
Authors: DUDHE RAVISHANKAR S. , RAVAL HARSHIL N. , KUMAR ANIL , RAO V. RAMGOPAL
Published: December 2011

Organic semiconducting material based sensors have been used for various environmental applications. Organic field effect transistors (OFETs) also find their applications in explosive vapor detection and total ionizing radiation dose determination. OFETs using poly 3-hexylthiophene (P3HT), a p-type organic semiconductor material and CuII tetraphenylporphyrin ( CuTPP ) composite as their active material were investigated as sensors for detection of various nitro-based explosive vapors with greater than parts per billion sensitivity range. Significant changes, suitable for sensor response, were observed in ON current (Ion) and transconductance (gm) extracted from electrical characteristics of the OFET after exposure to vapors of various explosive compounds. However, a similar device response was not observed to strong oxidizing agents such as benzoquinone (BQ) and benzophenone (BP). Also, the use of organic semiconducting material sensors for determining total ionizing radiation dose was studied, wherein the conductivity of the material was measured as a function of total ionizing radiation dose. An organic semiconducting material resistor was exposed to γ-radiation and it was observed that the change in resistance was proportional to the ionizing radiation dose. Changes in various parameters extracted from electrical characteristics of the OFET after γ-radiation exposure resulted in an improved sensitivity. To protect the organic semiconductor layer from the degradation in the ambient the sensors were passivated with a thin layer of silicon nitride.
Ag7 AND Ag8 QUANTUM CLUSTERS SUPPORTED ON ALUMINA: NEW CATALYSTS FOR ORGANIC REACTIONS
Authors: LEELAVATHI ANNAMALAI , BHASKARA RAO THUMU UDAYA , PRADEEP THALAPPIL
Published: December 2011

Silver quantum clusters (QCs) stabilized by mercaptosuccinic acid (MSA) have been synthesized at room temperature from Ag nanoparticles through an interfacial etching process. The as-synthesized red emitting QCs were coated on alumina and the supported clusters have been characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX) and fluorescence spectroscopy. Catalytic activity of Ag QCs supported on alumina have been exploited for the reduction of 4-nitrophenol in presence of sodium borohydride. The reaction followed pseudo-first order kinetics. The catalyst separated from the product remains active and can be recycled several times. Other nitroaromatic compounds have also been tested. Synthesis of the solid phase catalyst, applications and detailed kinetic studies of the reduction of 4-nitrophenol are reported.
NANOCRYSTALLINE TIN OXIDE THIN FILM AS A LOW LEVEL H2S GAS SENSOR
Authors: PATIL GANESH E. , KAJALE D. D. , JAIN G. H. , SHINDE S. D. , GAIKWAD V. B.
Published: December 2011

Tin oxide thin films were deposited on alumina substrates at 350°C by spray pyrolysis technique. The films were studied after annealing them in air at different temperatures 550°C, 750°C and 950°C for 30 min. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical absorption spectroscopy technique. The grain size was observed to be increased, ranging from 40 to 56.1 nm, with the increase in annealing temperature. Absorbance spectra were taken to examine the optical properties. The band gap energy was observed to be decreased with the increase in annealing temperature. These films were tested to various gases at different operating temperature ranging from 50°C to 450°C. The Tin Oxide film showed maximum sensitivity to H2S gas. The H2S sensing property of the SnO2 films was investigated with different annealing temperatures of the films and at different concentrations of H2S gas. It was found that the annealing temperature of the film significantly affects the sensitivity of the SnO2 to the H2S gas. The maximum sensitivity was found in case of the film annealed at temperature 950°C at the operating temperature 100°C. The sensitivity was found to be increased by 24% in case of the film annealed at 950°C as compared to the sensitivity of the film annealed at 550°C. The observed response of the film was for gas concentration of 10 ppm for H2S with reasonable sensitivity. The quick response and fast recovery are the main features of this film. The effect of annealing temperature on the structural, microstructural, optical and gas sensing properties of the nanocrystalline tin oxide thin films were studied and discussed.
ASSESSMENT ON THE TOXICITY OF ENGINEERED NANOPARTICLES ON THE LIFESTAGES OF MARINE AQUATIC INVERTEBRATE ARTEMIA SALINA
Authors: RAJASREE S. R. RADHIKA , KUMAR V. GANESH , ABRAHAM L. STANLEY , MANOHARAN N.
Published: December 2011

The unique characteristics of nanoparticles which are responsible for their myriad applications nevertheless also play an important role in producing toxicological effects, due to their massive surface area and surface reactivity, which make them a particularly serious environmental and occupational health risk. Our main objective was to assess the potential impact that nanoparticles may have on release into marine aquatic environments. We prepared nanoparticles by continuous sonication and by ultra filtration. Artemia salina was differentiated to five life stages based on certain easily distinguished features and were exposed to different concentrations of titanium dioxide and fullerene using 48 h acute toxicity testing. Images of the particle solutions were recorded using TEM and the median lethal concentration was determined in each life stage. Exposure to sonicated nanoparticles shows varied mortalities in different stages of A. salina where as filtered solutions showed increasing mortality with increase in concentration. This is meant as a preliminary to more elaborative studies on the effect of a wide spectrum of nanoparticle types on a range of representative organisms from a variety of organismal and population levels.
ETHANOL AND TRIMETHYL AMINE SENSING BYZnO-BASED NANOSTRUCTURED THIN FILMS
Authors: SIVALINGAM DURGAJANANI , RAYAPPAN JOHN BOSCO BALAGURU , GANDHI SAKTHIVEL , MADANAGURUSAMY SRIDHARAN , SEKAR RAJAN KALPOONDI , KRISHNAN UMAMAHESHWARI
Published: December 2011

Undoped and fluorine (F)-doped nanostructured zinc oxide ( ZnO ) thin films were deposited over glass substrates by spray pyrolysis technique using zinc acetate dihydrate with and without ammonium fluoride as dopant in precursor solution respectively. The deposition conditions and the concentration of the dopant were optimized to obtain nanostructured ZnO thin films. The film obtained from 0.05 M of zinc acetate aqueous solution and 20% F sprayed at the rate of 3 ml/min on preheated substrate kept at 503 K yielded spherical shape well-connected grains, which has large surface to volume ratio. The structural and morphological studies of the films were investigated by using X-ray diffraction (XRD) and scanning electron microscope (SEM) respectively. The diffraction peak positions in XRD confirmed the formation of highly crystalline ZnO film with hexagonal wurtzite phase. Further sensing behavior of the films towards various concentrations of volatile organic compounds (VOCs) such as ethanol and trimethyl amine (TMA) has been investigated at an optimized operating temperature of 373 K and reported.
SYNTHESIS OF COBALT NANOTUBULES AND CHARACTERIZATION OF MAGNETIZATION DYNAMICS
Authors: PATHAK SACHIN , SINGH SUKHVINDER , SHARMA MANISH
Published: December 2011

Magnetic nanowire arrays formed by templated electrodeposition are a promising way of making ultra-high density magnetic recording media. We have used both Poly Carbonate Track Etched (PCTE) and Anodic Aluminum Oxide (AAO) membranes to obtain Cobalt nanowires. Also by suitably adjusting the electrodeposition process, hollow Cobalt nanotubules were formed. The hollow cylindrical structure gives a unique capability to tailor their magnetization. The morphology of the samples was investigated using SEM and TEM. Magnetic characterization done using SQUID shows the influence of morphology and that the nanotubules have rather different switching behaviour than solid nanowires. Finite element micromagnetic modeling was performed of a single nanowire, a single nanotubule and also arrays of nanotubules. The calculated static M-H curves were found to match closely the SQUID measurements. The coercivity increases with length while the inner and outer diameters greatly affect rotational switching of the magnetization.
Chapter 2 A history of Neoproterozoic glacial geology, 1871–1997
Authors: Hoffman Paul F.
Published: December 2011

Neoproterozoic glacial records have been discovered on 23 palaeocontinents, their rate of discovery changing little since 1871. Yet, half of all the resulting publications appeared since 2000. The history of research before 1998 is described in five stages defined by publication spikes; subsequent work is not covered because historical perspective is lacking. In stage 1 (1871–1907), ‘Cambrian’ (now Neoproterozoic) glaciation was recognized successively in Scotland, Australia, India, Norway, Svalbard and China. Criteria for recognition included faceted and striated pebbles in matrix-supported conglomerates resting on ice-worn bedrock pavements. In stage 2 (1908–1940), Neoproterozoic glaciation was shown to have been widespread in Africa, Asia and the Americas. Major textbooks summarized these findings, but the rejection of continental drift (to account for late Palaeozoic glacial dynamics) put a chill on research. In stage 3 (1942–1964), the occurrence of glacial deposits within carbonate successions, as well as nascent palaeomagnetic observations, suggested that Neoproterozoic glaciers reached sea-level at low palaeolatitudes, but the belated recognition of sediment gravity flowage caused glacial interpretations to be prematurely abandoned in key areas. In stage 4 (1965–1981), the extent of Neoproterozoic glaciation was rethought in light of plate tectonics. Distinctive chemical sediments (iron±manganese formations and cap carbonates) were identified. In basic climate models, modest lowering of solar luminosity resulted in global glaciation due to ice-albedo feedback, and deglaciation due to greenhouse forcing resulted from silicate-weathering feedback in the carbon cycle. Neoproterozoic glacial geologists were blind to these ideas. In stage 5 (1982–1997), reliable palaeomagnetic data combined with glacial marine sedimentation models confirmed that Neoproterozoic ice sheets reached sea level close to the palaeoequator.