bluuebunny/crossref_metadata_2025 huggingface dataset:
Modifications in structural and electronic properties of TiO2 thin films using swift heavy ion irradiation
Authors: Thakur Hardeep , Kumar Ravi , Thakur P. , Brookes N. B. , Sharma K. K. , Pratap Singh Abhinav , Kumar Yogesh , Gautam S. , Chae K. H.
Published: November 2011

We report on the structural and electronic properties of swift heavy ion (SHI) irradiated pristine TiO2 thin films, deposited by radio frequency magnetron sputtering on sapphire substrates. The high resolution x-ray diffraction and Raman measurements show a structural phase transition from anatase to admixture of brookite and rutile phases of TiO2 with increasing SHI fluence followed by a significant distortion in the TiO6 octahedra. The modification in the electronic structure stimulated by SHI irradiation has been investigated using x-ray absorption (XAS) experiments at the O K and Ti L3,2 absorption edges. The O K edge spectra clearly indicate the splitting of the pre-edge spectral features having t2g and eg symmetry bands due to structural disorder/distortion induced by irradiation. The intensity of the SHI generated components at the O K edge increases monotonically, which can be correlated to the modification in unoccupancies associated with O 2 p orbitals hybridized with Ti 3 d states. The XAS spectra at the Ti L3,2 edge further authenticate that SHI creates a controlled structural disorder/distortion in the TiO6 octahedra.
Inkjet printing of single-walled carbon nanotube thin-film transistors patterned by surface modification
Authors: Nobusa Yuki , Yomogida Yohei , Matsuzaki Satoki , Yanagi Kazuhiro , Kataura Hiromichi , Takenobu Taishi
Published: November 2011

In this paper, we report a method for the inkjet printing of single-walled carbon nanotube thin-film transistors (SWCNT TFTs). Although inkjet technology is a powerful tool for the fabrication of SWCNT TFTs, the diameter of the ink droplets (100 μm) strictly limits the device size. Here, we surmount this limitation by combining inkjet technology and site-selective deposition based on the patterning of self-assembled monolayers. We have synthesized patterned SWCNT films with feature widths less than 100 μm using this site-selective surface modification method, thus improving the performance limit of SWCNT printed electronics.
Graphenated carbon nanotubes for enhanced electrochemical double layer capacitor performance
Authors: Stoner Brian R. , Raut Akshay S. , Brown Billyde , Parker Charles B. , Glass Jeffrey T.
Published: November 2011

This letter reports on nucleation and growth of graphene foliates protruding from the sidewalls of aligned carbon nanotubes (CNTs) and their impact on the electrochemical double-layer capacitance. Arrays of CNTs were grown for different time intervals, resulting in an increasing density of graphene foliates with deposition time. The samples were characterized using electrochemical impedance spectroscopy, scanning electron microscopy, and transmission electron microscopy. Both low and high frequency capacitance increased with increasing foliate density. A microstructural classification is proposed to explain the role of graphene edges, three-dimensional organization, and other features of hybrid carbon systems on their electrochemical properties.
Photoreflectance spectroscopy study of a strained-layer CdTe/ZnTe superlattice
Authors: Ferizović Dino , Peng Le , Sultana Humara , Mukherjee Pritish , Witanachchi Sarath , Tamargo María C. , Muñoz Martín
Published: November 2011

This work presents a study of energy transitions in a strained-layer CdTe/ZnTe superlattice. The energy transitions were determined using photoreflectance spectroscopy and calculations based on a transfer matrix method that incorporates both band non-parabolicity and strain induced effects. The observed transitions have their origin in the Γ and Π critical points of the superlattice minibands. Furthermore, the calculations for the energy levels of the superlattice indicate that the valence band offset between CdTe and ZnTe is 102 meV and that the superlattice ground state is associated with the lowest light hole energy level.
Examination of insulator regime conduction mechanisms in epitaxial and polycrystalline SmNiO3 thin films
Authors: Ha Sieu D. , Aydogdu Gulgun H. , Ramanathan Shriram
Published: November 2011

Correlated oxides that exhibit metal–insulator phase transitions are emerging as potential candidates for switching devices. One such material is SmNiO3, which has a transition temperature above room temperature (∼400 K in bulk crystals). In this work, we study temperature- and bias-dependent conduction mechanisms in epitaxial and polycrystalline SmNiO3 thin films. In both cases, at low electric field we observe thermally assisted hopping conduction through defect states with activation energies of ∼170 meV and ∼270 meV, respectively. At high electric field the conduction transitions to a space-charge limited regime controlled by an exponential trap distribution. The power law exponents are ∼3 in epitaxial films and ∼8–14 in polycrystalline films. The trap decay parameter in epitaxial films does not have the expected 1/T temperature dependence, which may be a signature of bandgap narrowing at high temperature because of the insulator-to-metal transition. The larger activation energy and power law dependency in polycrystalline films are consistent with additional defect density from extraneous phases. In polycrystalline films, current-voltage data measured perpendicular to the film surface are rectifying because of asymmetry in electrode work functions with a ratio of 104 at ± 1 V. We find that whereas the space-charge limited conduction for positive bias is bulk limited, the negative bias conduction is injection limited.
Evolution of magnetic anisotropy and thermal stability during nanocrystal-chain growth
Authors: Charilaou M. , Sahu K. K. , Faivre D. , Fischer A. , García-Rubio I. , Gehring A. U.
Published: November 2011

We compare measurements and simulations of ferromagnetic resonance spectra of magnetite nanocrystal-chains at different growth-stages. By fitting the spectra, we extracted the cubic magnetocrystalline anisotropy field and the uniaxial dipole field at each stage. During the growth of the nanoparticle-chain assembly, the magnetocrystalline anisotropy grows linearly with increasing particle diameter. Above a threshold average diameter of D ≈ 23 nm, a dipole field is generated, which then increases with particle size and the ensemble becomes thermally stable. These findings demonstrate the anisotropy evolution on going from nano to mesoscopic scales and the dominance of dipole fields over crystalline fields in one-dimensional assemblies.
Dipole-dipole interaction in a quantum dot and metallic nanorod hybrid system
Authors: Singh Mahi R. , Schindel Daniel G. , Hatef Ali
Published: November 2011

We have studied quantum coherence and interference phenomena in a quantum dot (QD)-metallic nanorod (MNR) hybrid system. Probe and control laser fields are applied to the hybrid system. Induced dipole moments are created in the QD and the MNR, and they interact with each other via the dipole-dipole interaction. Using the density matrix method, it was found that the power spectrum of MNR has two transparent, states and they can be switched to one transparent state by the control field. Ultrafast switching and sensing nanodevices could be produced using this model.
Electrical detection of DNA immobilization and hybridization by streaming current measurements in microchannels
Authors: Martins D. C. , Chu V. , Prazeres D. M. F. , Conde J. P.
Published: November 2011

Label-free electrical detection of surface DNA immobilization and hybridization via streaming current measurements in a microchannel is demonstrated. Streaming currents generated by the flow of deionised water through a polydimethysiloxane microchannel sealed on glass are measured using integrated Au electrodes and are sensitive to the density and polarity of the charge on the channel surface. An in-channel DNA hybridization protocol was developed. Streaming currents were monitored after each of protocol steps. The technique was applied to label free recognition of DNA hybridization and could distinguish between assays with complementary and non-complementary DNA strands.
Deep donor state in InN: Temperature-dependent electron transport in the electron accumulation layers and its influence on Hall-effect measurements
Authors: Ma N. , Wang X. Q. , Liu S. T. , Feng L. , Chen G. , Xu F. J. , Tang N. , Lu L. W. , Shen B.
Published: November 2011

Temperature-dependent electron transport properties in electron accumulation layers of InN are quantified by using the multilayer model. Room temperature electron densities in the electron accumulation layers are 5.83 × 1013 and 3.26 × 1014 cm−2 with Hall mobilities of 429 and 149 cm2/Vs in In- and N-polarity InN, respectively. A deep donor state with an activation energy of ∼80 meV, which is previously believed to exist in the InN bulk layer, is found to actually locate in the electron accumulation layers. The InN bulk layer shows single-shallow-donor behavior and its temperature-dependent electron mobility is in good agreement with the ensemble Monte Carlo simulation results.
Response to “Comment on ‘Indications of energetic consequences of decoherence at short times for scattering from open quantum systems’” [AIP Advances 1, 049101 (2011)]
Authors: Chatzidimitriou-Dreismann C. A. , Gray E. MacA. , Blach T. P.
Published: November 2011

The Comment by Mayers and Reiter criticizes our work on two counts. Firstly, it is claimed that the quantum decoherence effects that we report in consequence of our experimental analysis of neutron Compton scattering from H in gaseous H2 are not, as we maintain, outside the framework of conventional neutron scattering theory. Secondly, it is claimed that we did not really observe such effects, owing to a faulty analysis of the experimental data, which are claimed to be in agreement with conventional theory. We focus in this response on the critical issue of the reliability of our experimental results and analysis. Using the same standard Vesuvio instrument programs used by Mayers et al., we show that, if the experimental results for H in gaseous H2 are in agreement with conventional theory, then those for D in gaseous D2 obtained in the same way cannot be, and vice-versa. We expose a flaw in the calibration methodology used by Mayers et al. that leads to the present disagreement over the behaviour of H, namely the ad hoc adjustment of the measured H peak positions in TOF during the calibration of Vesuvio so that agreement is obtained with the expectation of conventional theory. We briefly address the question of the necessity to apply the theory of open quantum systems.
Body composition in athletes: A comparison of densitometric methods and tracking of individual differences
Authors: Peeters Maarten Wim , Goris Marina , Keustermans Greet , Pelgrim Koen , Claessens Albrecht L.
Published: November 2011

Measuring body composition in athletes can provide valuable information on training and nutritional status. The aim of this study was to compare percentage body fat (PF) obtained by hydrostatic weighing (HW) to PF via air‐displacement plethysmography (ADP), and to evaluate tracking of individual differences between both methods over time in elite college athletes. Thirty‐one male and 33 female athletes (18.0–36.4 years) were measured by ADP and HW. Twenty‐one subjects (10 men, 11 women) were measured again 61±11 days later to evaluate consistency of individual differences between methods. Mean PF differed significantly in men (HW: 9.4±2.4%, ADP: 11.3±3.4%, P<0.05) but not in women (HW: 19.1±2.4%, ADP: 19.5±3.7%). A significant trend in mean bias was found in both genders between HW‐ADP suggesting an underestimation of PF by ADP at lower mean PF and an overestimation of PF by ADP at higher mean PF. Up to 73% of variance in differences between methods at follow‐up was explained by differences between methods at the first measurement occasion. Both densitometric methods cannot be used interchangeably when measuring and tracking the body composition of individual elite athletes using a 2‐component model of body composition. Differences between methods appear to track within an individual. The individual‐specific causes of these differences remain to be determined.
Several RNase T2 enzymes function in induced tRNA and rRNA turnover in the ciliate Tetrahymena
Authors: Andersen Kasper L. , Collins Kathleen
Published: November 2011

RNase T2 enzymes are produced by a wide range of organisms and have been implicated to function in diverse cellular processes, including stress-induced anticodon loop cleavage of mature tRNAs to generate tRNA halves. Here we describe a family of eight RNase T2 genes (RNT2A–RNT2H) in the ciliate Tetrahymena thermophila. We constructed strains lacking individual or combinations of these RNT2 genes that were viable but had distinct cellular and molecular phenotypes. In strains lacking only one Rnt2 protein or lacking a subfamily of three catalytically inactive Rnt2 proteins, starvation-induced tRNA fragments continued to accumulate, with only a minor change in fragment profile in one strain. We therefore generated strains lacking pairwise combinations of the top three candidates for Rnt2 tRNases. Each of these strains showed a distinct starvation-specific profile of tRNA and rRNA fragment accumulation. These results, the delineation of a broadened range of conditions that induce the accumulation of tRNA halves, and the demonstration of a predominantly ribonucleoprotein-free state of tRNA halves in cell extract suggest that ciliate tRNA halves are degradation intermediates in an autophagy pathway induced by growth arrest that functions to recycle idle protein synthesis machinery.
Genetic and Phenotypic Diversity of Sclerotium rolfsii in Groundnut Fields in Central Vietnam
Authors: Le C. N. , Mendes R. , Kruijt M. , Raaijmakers J. M.
Published: November 2011

Groundnut (Arachis hypogaea) is an economically important legume crop in Vietnam and many other countries worldwide. Stem and pod rot, caused by the soilborne fungus Sclerotium rolfsii, is a major yield-limiting factor in groundnut cultivation. To develop sustainable measures to control this disease, fundamental knowledge of the epidemiology and diversity of S. rolfsii populations is essential. In this study, disease incidence was monitored in eight groundnut areas in central Vietnam with a total of 240 observational field plots. The results showed that 5 to 25% of the field-grown groundnut plants were infected by S. rolfsii. Based on internal transcribed spacer (ITS) ribosomal DNA sequence analyses, three distinct groups were identified among a total of 103 randomly selected S. rolfsii field isolates, with the majority of the isolates (n = 90) in one ITS group. S. rolfsii isolates originating from groundnut, tomato, and taro were all pathogenic on groundnut and relatively sensitive to the fungicide tebuconazole but displayed substantial diversity of various genetic and phenotypic traits, including mycelial compatibility, growth rate, and sclerotial characteristics.
Species diversity and abundance of small mammals in Nechisar National Park, Ethiopia
Authors: Workeneh Sintayehu , Bekele Afework , Balakrishnan Mundanthra
Published: November 2011

Species diversity and abundance of small mammals were studied in Nechisar National Park, Ethiopia, during August 2008 – March 2009. Twenty species of rodents and four species of insectivores were recorded from the study area. Mastomys natalensis (17.37%), Arvicanthis dembeensis (17.09%), Mastomys erythroleucus (8.90%), Stenocephalemys albipes (8.76%), Arvicanthis niloticus (8.19%), Acomys cahirinus (7.34%), Lemniscomys striatus (6.92%), Gerbilliscus nigricauda (6.21%), Grammomys dolichurus (3.67%), Gerbilliscus robusta (2.12%), Mus proconodon (1.98%), Mus mahomet (1.41), Dendromus melanotis (1.27%), Arvicanthis abyssinicus (1.13%), Mus musculus (0.99%), Praomys fumatus (0.85%), Xerus erythropus (0.85%), Lemniscomys barbarus (0.71%), Mus tenellus (0.71%) and Otomys typus (0.28%) were the rodents and their respective relative abundance in the study area. Crocidura olivieri (1.55%), Crocidura fumosa (0.85%), Crocidura bicolor (0.57%) and Elephantulus rufescens (0.28%) were the insectivores recorded with their respective relative abundance. Mastomys natalensis was the most abundant and O. typus and E. rufescens were the least (two each). Diversity of small mammals ranged from 2.299 to 2.625 with an average of 2.412. The highest small mammal diversity was in grasslands and the lowest was in Lake Chamo shore. Small mammal density varied from 5 to 43 ha−1 and biomass varied from 244 to 2559 g ha−1 with significant changes in relation to seasons and habitats.
Genetic diversity and structure of wild Tunisian Thymus capitatus (L.) Hoffm. et Link. (Lamiaceae) assessed using isozyme markers
Authors: El Hadj Ali Imen Ben , Guetat Arbi , Boussaid Mohamed
Published: November 2011

The genetic diversity and population structure of 25 natural populations of Thymus capitatus, from five ecological areas, were analysed using eight isozymes. For all populations, 11 polymorphic loci were detected, and several of them showed rare alleles. A high genetic diversity within populations (Ap = 1.82; P = 62.88%; Ho = 0.116) and an excess of heterozygosity were observed. A high level of inbreeding within populations was observed (FIS = 0.471). High differentiation and low gene flow (Nm = 0.821) were detected among populations (FST = 0.219). The genetic variation within and among ecological groups varied according to the bioclimate. Population structuration depends on geographic distance between sites rather than on bioclimate (Mantel’s test; r = 0.251; P = 0.004). Nei’s genetic distances (D) values calculated between pairs of populations were globally low with a mean of 0.047. The unweighted pairwise groups method using arithmetic average dendrogram showed fourth sub‐clusters. Population groupings occur with evident relationship to geographic location. The substantial differentiation and the high genetic similarities between populations indicate that populations have been recently isolated as a result of anthropic pressure. In situ conservation must first focus on populations with a high level of genetic diversity and rare alleles. Ex situ preservation should be elaborated by collecting seeds within populations that showed a high level of genetic diversity in each ecological group.
Effects of stocking on the genetic structure of brown trout, Salmo trutta, in Central Europe inferred from mitochondrial and nuclear DNA markers
Authors: KOHOUT J. , JAŠKOVÁ I. , PAPOUŠEK I. , ŠEDIVÁ A. , ŠLECHTA V.
Published: November 2011

Abstract  Stocking has had a considerable effect on wild brown trout, Salmo trutta L., populations throughout Europe. To elucidate this impact and to outline further management strategies, the genetic structure of 25 wild populations and five hatchery stocks from Czech Republic and Slovakia were analysed using mitochondrial (control region) and nuclear DNA (microsatellites, LDH‐C1*) markers. Stocking practices have caused massive hybridisation between the Atlantic and Danube brown trout strains in the central Danube basin and have lead to a loss of among‐population divergence in Slovakia and the eastern part of Czech Republic. Comparison with studies from neighbouring countries revealed substantial differences in haplotype, allele frequencies and genetic diversity across Central Europe. Differences in stocking management and origin of breeding stocks appear to be crucial factors for the spatial variability of the genetic structure of brown trout.
The role of ultrasonography in the diagnosis of the musculo‐skeletal problems of haemophilia
Authors: QUEROL F. , RODRIGUEZ‐MERCHAN E. C.
Published: November 2011

Summary.  Recurrent haemarthrosis is the final cause of haemophilic arthrosic disease in haemophilia patients. Therefore, it is essential to diagnose it early, both clinically and by imaging. In addition, haemophilia patients experience chronic synovitis, joint degeneration, muscle haematoma and pseudotumours. The objective of this article is to highlight the value of ultrasounds in the diagnosis and control of the evolution of musculo‐skeletal problems in haemophilia patients. To this end, we have performed a literature search in the PubMed, Web of Science® (WOS) and SciVerse bases, using the following keywords: hemophilia or haemophilia and ultrasonography (US), ultrasound, echography and sonography. The search was limited to studies published in English between the years 1991 and 2011, finding a total of 221 references. After reviewing the title or abstract for evidence of the use of US for the diagnosis of musculo‐skeletal lesions in haemophilia, we selected 24 of these references. We added data collected from our experience to the most important data found in the references. Our main conclusion is that US is highly valuable for the diagnosis of musculo‐skeletal diseases in haemophilia. It is a fast, effective, safe, available, comparative, real‐time technique that can help us confirm the clinical examination. It is particularly important in acute haemarthrosis, as it can be used to objectively identify the presence of blood in the joints, measure its size, pinpoint its location, assess its evolution and confirm its complete disappearance.
Quality clinical placements for undergraduate nursing students: a cross‐sectional survey of undergraduates and supervising nurses
Authors: Courtney‐Pratt Helen , FitzGerald Mary , Ford Karen , Marsden Kathryn , Marlow Annette
Published: November 2011

courtney‐pratt h., fitzgerald m., ford k., marsden k. & marlow a. (2012) Quality clinical placements for undergraduate nursing students: a cross‐sectional survey of undergraduates and supervising nurses. Journal of Advanced Nursing68(6), 1380–1390.

Aim.  This article is a report of a mixed method study of the quality of clinical placements for second year undergraduate nursing students in an acute care hospital.

Background.  In response to the current and predicted workforce shortages, greater numbers of nursing undergraduate places are being offered at tertiary institutions. This means that requests for clinical places in hospitals to support undergraduate students has risen. Little is known about the impact of increased numbers on the quality of clinical placement as a learning experience and this is of concern as demand grows and the means of assessing capacity is still unknown.

Methods.  A 5‐point Likert Scale questionnaire, including free text fields, was administered to undergraduates (n = 178), clinical facilitators (n = 22) and supervising ward nurses (n = 163) at two time points in 2009. The survey targeted the quality of the clinical placement in four domains: welcoming and belongingness; teaching and learning; feedback; confidence and competence.

Findings.  The findings demonstrated consistently high scoring of the clinical placement experience by both undergraduates and registered nurses. There were higher ratings of levels of support from clinical facilitators compared to supervising ward nurses evident in data associated with the items on the questionnaire relating to teaching and learning.

Conclusion.  The results are indicative of the professional commitment of nursing staff to support the next generation of nurses. The findings also give a mechanism to communicate outcomes of undergraduate support to nurses in practice, and highlight steps which can be taken to ensure high quality clinical placement continues.
Admissions related to interstitial cystitis in Japan: An estimation based on the Japanese Diagnosis Procedure Combination database
Authors: Sugihara Toru , Yasunaga Hideo , Horiguchi Hiromasa , Nakamura Mitsuhiro , Nomiya Akira , Nishimatsu Hiroaki , Matsuda Shinya , Homma Yukio
Published: November 2011

We estimated the incidence of admissions related to interstitial cystitis in Japan using a national administrative claims database, the Diagnosis Procedure Combination database, which included information for 53.6% of urological training hospitals certified by the Japanese Urological Association. “Admissions related to interstitial cystitis” was defined as those cases whose ICD‐10 code for the main reason for admission was N301 (interstitial cystitis) between 2007 and 2009. Among 8.42 million inpatient cases, 784 female and 212 male patients with interstitial cystitis were identified. The ratio of females to males was 3.69 and the median age was 67 years (range 5–92 years). The admission incidence (per 100 000 person‐years) in females and males was estimated to be 1.35 (95% confidence interval 1.25–1.46) and 0.37 (0.31–0.42), respectively. This incidence is low compared with other reports. Possible reasons for this finding include racial difference, clinical examination methods, lack of outpatient data and poor health‐care coverage of interstitial cystitis.
Incidence of retinopathy of prematurity in extremely premature infants over an 18‐year period
Authors: Gunn David J , Cartwright David W , Gole Glen A
Published: November 2011

Abstract

Background:  To report the incidence of retinopathy of prematurity (ROP) in a subgroup of extremely premature infants admitted to an Australian tertiary centre over an 18‐year period.

Design:  Retrospective study. Royal Brisbane and Women's Hospital Neonatal Intensive Care Unit.

Participants:  Five hundred and fifty‐four infants admitted between 23 and 25.6 weeks gestational age (GA).

Methods:  The 18‐year study was divided into three 6‐year periods for analysis: period 1 (1992–1997), period 2 (1998–2003) and period 3 (2004–2009). Infants were compared based on their week of GA and by the study period in which they were born.

Main Outcome Measures:  GA, birthweight, incidence and severity of ROP.

Results:  Three hundred seventy‐three (67.3%) infants survived until ROP screening, and 351 (63.4%) survived until discharge. ROP incidence increased from 78.2% in period 1 to 86.1% in period 3. Over the entire study, 90.5% of 23‐week GA infants had ROP compared with 89.7% of 24‐week GA infants and 76.1% of 25‐week GA infants. Mean birthweight was significantly lower in infants with any ROP (725.1 g) and ROP of at least stage 3 (720.8 g) compared with infants without ROP (806.5 g) (P < 0.0001). Twenty‐three–week GA infants had more severe ROP (28.6%) than 24 weeks (18.3%) and 25 weeks GA (11.9%).

Conclusions:  There has been increased survival and incidence of ROP in extremely premature infants over the past 20 years. Lower birthweight and GA are both associated with higher incidence and more severe ROP.
A quantitative assessment of fish passage efficiency
Authors: Noonan Michael J , Grant James W A , Jackson Christopher D
Published: November 2011

In an attempt to restore the connectivity of fragmented river habitats, a variety of passage facilities have been installed at river barriers. Despite the cost of building these structures, there has been no quantitative evaluation of their overall success at restoring fish passage. We reviewed articles from 1960 to 2011, extracted data from 65 papers on fish passage efficiency, size and species of fish, and fishway characteristics to determine the best predictors of fishway efficiency. Because data were scarce for fishes other than salmonids (order Salmoniformes), we combined data for all non‐salmonids for our analysis. On average, downstream passage efficiency was 68.5%, slightly higher than upstream passage efficiency of 41.7%, and neither differed across the geographical regions of study. Salmonids were more successful than non‐salmonids in passing upstream (61.7 vs. 21.1%) and downstream (74.6 vs. 39.6%) through fish passage facilities. Passage efficiency differed significantly between types of fishways; pool and weir, pool and slot and natural fishways had the highest efficiencies, whereas Denil and fish locks/elevators had the lowest. Upstream passage efficiency decreased significantly with fishway slope, but increased with fishway length, and water velocity. An information‐theoretic analysis indicated that the best predictors of fish passage efficiency were order of fish (i.e. salmonids > non‐salmonids), type of fishway and length of fishway. Overall, the low efficiency of passage facilities indicated that most need to be improved to sufficiently mitigate habitat fragmentation for the complete fish community across a range of environmental conditions.
Human responding with mutual reinforcement: Baseline and effects of an intervention1
Authors: OKOUCHI HIROTO
Published: November 2011

Pressing a key by one undergraduate provided another undergraduate with points exchangeable for money, and vice versa. Four types of response patterns were found. Points were often delivered with a delay from the last response or with no response. When a contingency that responses lost points (punishment) was added to participants who had emitted more responses than the partner had, their response rates decreased while the rates of their partners increased. These results demonstrate that, under the contingency of mutual reinforcement: (a) response patterns that had occurred between monkeys were replicated between humans; (b) obtained response‐reinforcer relations were different from those generally programmed in the basic reinforcement schedules; and (c) the behavior of the participant was controlled by changing the behavior of the partner.
Increased brain‐derived neurotrophic factor (BDNF) expression in the ventral tegmental area during cocaine abstinence is associated with increased histone acetylation at BDNF exon I‐containing promoters
Authors: Schmidt Heath D. , Sangrey Gavin R. , Darnell Shayna B. , Schassburger Rachel L. , Cha Jang‐Ho J. , Pierce R. Christopher , Sadri‐Vakili Ghazaleh
Published: November 2011

J. Neurochem. (2012) 120, 202–209.

Recent evidence suggests that the persistence of cocaine seeking during periods of protracted drug abstinence following chronic cocaine exposure is mediated, in part, by neuroadaptations in the mesolimbic dopamine system. Specifically, incubation of cocaine‐seeking behavior coincides with increased brain‐derived neurotrophic factor (BDNF) protein expression in the ventral tegmental area (VTA). However, the molecular mechanisms that regulate time‐dependent changes in VTA BDNF protein expression during cocaine abstinence are unclear. The goal of these experiments was to determine whether VTA BDNF transcript levels are altered following cocaine abstinence and identify the molecular mechanisms regulating cocaine‐induced changes in VTA BDNF transcription. Rats were allowed to self‐administer cocaine (0.25 mg/infusion, i.v.) for 14 days on a fixed‐ratio schedule of reinforcement followed by 7 days of forced drug abstinence. BDNF protein and exon I‐containing transcripts were significantly increased in the VTA of cocaine‐experienced rats following 7 days of forced drug abstinence compared to yoked saline controls. Cocaine‐induced changes in BDNF mRNA were associated with increased acetylation of histone 3 and binding of CREB‐binding protein to exon I‐containing promoters in the VTA. Taken together, these results suggest that drug abstinence following cocaine self‐administration remodels chromatin in the VTA resulting in increased expression of BDNF, which may contribute to neuroadaptations underlying cocaine craving and relapse.
Liposomal formulation of curcumin attenuates seizures in different experimental models of epilepsy in mice
Authors: Agarwal Nidhi Bharal , Jain Seema , Nagpal Dheeraj , Agarwal Nitin Kumar , Mediratta Pramod K. , Sharma Krishna K.
Published: November 2011

Contemporary research indicates promising anticonvulsant effect of curcumin. However, its poor oral bioavailability is a major hindrance toward its pharmacological action. Thus, this study was carried out to evaluate the acute effect of liposome‐entrapped curcumin on increasing current electroshock seizures (ICES) test, pentylenetetrazole (PTZ)‐induced seizures, and status epilepticus in mice. Liposome‐entrapped curcumin in doses 25 and 50 mg/kg demonstrated significant increase in seizure threshold current and latency to myoclonic and generalized seizures in ICES test and PTZ‐induced seizures, respectively. Similarly, liposomal‐entrapped curcumin also increased the latency to the onset and decreased the duration of seizures during status epilepticus in mice. To conclude, liposomal‐entrapped curcumin possesses anticonvulsant activity against status epilepticus in mice.
Gene‐specific alterations of hepatic gene expression by ligand activation or hepatocyte‐selective inhibition of retinoid X receptor‐α signalling during inflammation
Authors: Kosters Astrid , Tian Feng , Wan Yvonne Yu‐Jie , Karpen Saul J.
Published: November 2011

Background

Inflammation leads to transcriptional downregulation of many hepatic genes, particulary those activated by retinoid X receptor‐α (RXRα) heterodimers. Inflammation‐mediated reduction of nuclear RXRα levels is a main factor in reduced nuclear receptor (NR)‐regulated hepatic gene expression, eventually leading to cholestasis and liver damage.

Aim

To investigate roles for RXRα in hepatic gene expression during inflammation, using two complementary mouse models: ligand activation of RXRα, and in mice expressing hepatocyte‐specific expression of RXRα missing its DNA‐binding domain (DBD; hs‐RxrαΔex4−/−).

Methods

To activate RXRα, mice were gavage‐fed with LG268 or vehicle for 5 days. To inhibit RXRα function, hs‐RxrαΔex4−/− mice were used. All mice were injected intraperitoneally with lipopolysaccharides (LPS) or saline for 16 h prior to analysis of hepatic RNA, protein and NR–DNA binding.

Results

LG268 treatment attenuated the LPS‐mediated reductions of several RXRα‐regulated genes, coinciding with maintained RXRα occupancy in both Bsep and Ostβ promoters. Lacking full hepatocyte RXRα function (hs‐RxrαΔex4−/− mice) led to enhancement of LPS‐mediated changes in gene expression, but surprisingly, maintenance of RNA levels of some RXRα‐regulated genes. Investigations revealed that hs‐RxrαΔex4−/− hepatocytes expressed an internally truncated, approximately 44 kDa, RXRα‐form. DNA‐binding capacity of NR heterodimers was equivalent in wild‐type and hs‐RxrαΔex4−/− livers, but reduced by LPS in both. Chromatin immunoprecipitation quantitative PCR revealed that RXRα occupancy to the Bsep RXRα:Farnesoid X Receptor site was reduced, but not absent, in hs‐RxrαΔex4−/− livers.

Conclusions

There are differential regulatory roles for hepatic RXRα, both in basal and inflammatory states, suggesting new and complex multidomain roles for RXRα in regulating hepatic gene expression. Moreover, there is an unexpected non‐obligate role for the DBD of RXRα.
Serotonin 1A receptors, depression, and memory in temporal lobe epilepsy
Authors: Theodore William H. , Wiggs Edythe A. , Martinez Ashley R. , Dustin Irene H. , Khan Omar I. , Appel Shmuel , Reeves‐Tyer Pat , Sato Susumu
Published: November 2011

Purpose:  Memory deficits and depression are common in patients with temporal lobe epilepsy (TLE). Previous positron emission tomography (PET) studies have shown reduced mesial temporal 5HT1A‐receptor binding in these patients. We examined the relationships among verbal memory performance, depression, and 5HT1A‐receptor binding measured with 18F‐trans‐4‐fluoro‐N‐2‐[4‐(2‐methoxyphenyl)piperazin‐1‐yl]ethyl‐N‐(2‐pyridyl) cyclohexane carboxamide (18FCWAY) PET in a cross‐sectional study.

Methods:  We studied 40 patients (24 male; mean age 34.5 ± 10.7 years) with TLE. Seizure diagnosis and focus localization were based on ictal video–electroencephalography (EEG) recording. Patients had neuropsychological testing with Wechsler Adult Intelligence Score III (WAIS III) and Wechsler Memory Score III (WMS III) on stable antiepileptic drug (AED) regimens at least 24 h since the last seizure. Beck Depression Inventory (BDI) scores were obtained. We performed interictal PET with 18FCWAY, a fluorinated derivative of WAY 100635, a highly specific 5HT1A ligand, and structural magnetic resonance imaging (MRI) scans to estimate partial volume and plasma free fraction corrected 18FCWAY volume of distribution (V/f1).

Key Findings:  Hippocampal V/f1 was significantly lower in area ipsilateral than contralateral to the epileptic focus (73.7 ± 27.3 vs. 95.4 ± 28.4; p < 0.001). We found a significant relation between both left hippocampal 18FCWAY V/f1 (r = 0.41; p < 0.02) and left hippocampal volume (r = 0.36; p < 0.03) and delayed auditory memory score. On multiple regression, there was a significant effect of the interaction of left hippocampal 18FCWAY V/f1 and left hippocampal volume on delayed auditory memory, but not of either alone. High collinearity was present. In an analysis of variance including the side of the seizure focus, the effect of left hippocampal 18FCWAY V/f1 but not focus laterality retained significance. Mean BDI was 8.3 ± 7.0. There was a significant inverse relation between BDI and 18FCWAY V/f1 ipsilateral to the patient’s epileptic focus (r = 0.38 p < 0.02). There was no difference between patients with a right or left temporal focus. There was no relation between BDI and immediate or delayed auditory memory.

Significance:  Our study suggests that reduced left hippocampal 5HT1A‐receptor binding may play a role in memory impairment in patients with TLE.
The human immunodeficiency virus‐1 genotype diversity and drug resistance mutations profile of volunteer blood donors from Chinese blood centers
Authors: Zeng Peibin , Wang Jingxing , Huang Yi , Guo Xiaoming , Li Julin , Wen Guoxin , Yang Tonghan , Yun Zhongqiao , He Miao , Liu Yu , Yuan Yuzhe , Schulmann Jane , Glynn Simone , Ness Paul , Jackson J. Brooks , Shan Hua ,   for the NHLBI Retrovirus Epidemiology Donor Study‐II (REDS‐II), International Component
Published: November 2011

BACKGROUND: The global human immunodeficiency virus (HIV)‐1 epidemic is becoming increasingly diverse and complex. Molecular epidemiologic characteristics were studied for HIV‐1–infected blood donors from five Chinese regions to determine genotype diversity and drug resistance mutations (DRMs) profile.

STUDY DESIGN AND METHODS: HIV‐1 confirmed‐reactive serum samples were collected from 172 blood donors from five blood centers during 2007 to 2010. HIV‐1 Pol including whole protease and partial reverse transcriptase genes was amplified, sequenced, and analyzed for the subtype determination and drug resistance profile description.

RESULT: A total of 113 amplified sequences including 82 from Kunming blood center and 31 from four other blood centers had the following genotype characteristics: G (0.9%), B (2.7%), circulating recombinant form (CRF) 01_AE (32.7%), CRF07_BC (22.1%), and CRF08_BC (41.6%). Female donors represent 45.1% of all cases and 63.9% cases with DRMs. The prevalence of samples with potential low or higher resistance among Chinese blood donors is 4.4%.

CONCLUSION: HIV‐1 infection in Chinese blood donors is genetically diverse and the subtype distribution reflects that from the high‐risk populations. Our results support continuous molecular epidemiologic surveillance for HIV‐1 in blood donors as a part of a comprehensive HIV control program.
Left Atrial Metastases of Poorly Differentiated Thyroid Carcinoma Diagnosed by Echocardiography and Magnetic Resonance Imaging—Case Report and Review of Literature
Authors: Bertoldi Eduardo Gehling , Severo Mateus Dornelles , Scheffel Rafael Selbach , Foppa Murilo , de Azevedo Mirela Jobim , Maia Ana Luiza
Published: November 2011

Intracardiac metastases of thyroid carcinoma are a rare event. Their incidence is low in large autopsy series, and antemortem diagnosis is even less common. We present the case of a woman with advanced poorly differentiated thyroid carcinoma who had extensive intracardiac metastases. This case highlights the usefulness of echocardiography and magnetic resonance imaging in the diagnosis and differential diagnosis of cardiac metastases. (Echocardiography 2012;29:E30‐E33)
Left Ventricular Function and Exercise Capacity in Patients with Slow Coronary Flow
Authors: Elsherbiny Islam A.
Published: November 2011

Background: Endothelial and microvascular dysfunction have been implicated in slow coronary flow (SCF). How and to what extent do these etiological factors affect left ventricular (LV) function and exercise capacity? Aim: The aim of the study was to evaluate LV systolic and diastolic function by pulsed tissue Doppler imaging (TDI) in SCF patients and their effects on exercise capacity. Subjects and methods: Sixty SCF patients and 20 control subjects were included in the study. Echocardiographic examination, treadmill exercise test, and TDI were performed. Isovolumic myocardial acceleration (IVA) and myocardial performance index (MPI) were measured. Results: TDI mean parameters for systolic and diastolic LV function were significantly impaired in SCF group with decreased Sa, IVA, Ea/Aa, and increased MPI (0.31 ± 0.06 vs. 0.26 ± 0.04, P < 0.01) compared to control. There was significant correlation between thrombolysis in myocardial infarction (TIMI) frame count and TDI mean parameters for LV systolic function (Sa & IVA, r =−0.53, P < 0.01 & r =−0.36, P < 0.05, respectively). Mean TIMI frame count was correlated with MPI and E/Ea. SCF patients had poorer peak exercise capacity than the controls (9.9 ± 1.9 METs vs. 12.7 ± 2.3, P < 0.01) with significant negative correlation with mean TIMI frame count (r =−0.46, P < 0.01). Conclusion: There is impairment of LV systolic and diastolic function in SCF patients with clinical impact on exercise capacity which emphasizes the importance of close follow‐up of these patients for risk stratification. (Echocardiography 2012;29:158‐164)
Diagnostic Utility and Clinical Usefulness of the Pocket Echocardiographic Device
Authors: Michalski Błażej , Kasprzak Jarosław D. , Szymczyk Ewa , Lipiec Piotr
Published: November 2011

Background: The pocket echocardiograph (PE) with color Doppler imaging belongs to a new class of diagnostic tools, the feasibility and accuracy of which is not well established. The aim of this study was to assess the feasibility and diagnostic value of transthoracic echocardiography (TTE) performed with the use of PE by a cardiology resident (2nd year of training) and by an experienced cardiologist. Methods: The study population comprised 220 consecutive patients (142 men, mean age 63 ± 8 years), 110 of whom were admitted to our intensive cardiac care unit (ICU) and 110 patients referred for TTE from the outpatient clinic. All patients had PE TTE performed by a resident (60 ICU patients, 60 outpatients) or a cardiologist (50 ICU patients, 50 outpatients). Within 24 h of PE TTE, all subjects had a standard TTE (sTTE) performed by an experienced echocardiographer. Results: 96% of patients had echocardiographic measurements completed by both PE TTE and sTTE. The dimensions measured with PE TTE by the resident and the cardiologist showed good to excellent correlation with sTTE (r = 0.64–0.96, P < 0.001). The agreement in detection of various pathologies between PE TTE performed by the resident and sTTE examinations was moderate to very good, whereas it was good to excellent if PE TTE was performed by the experienced cardiologist. Conclusion: The diagnostic accuracy of the PE in basic assessment of cardiac morphology and function as compared to standard echocardiography is moderate to very good for a cardiology resident and good to excellent for an experienced cardiologist. (Echocardiography 2012;29:1‐6)
Double Cardiac Silhouette on Lateral Chest X‐Ray Graphy
Authors: Basaran Ozcan , Guler Ahmet , Karabay Can Y. , Aung Soe M. , Kalayci Arzu , Kirma Cevat
Published: November 2011

(Echocardiography 2012;29:E52‐E53)
Comparative histological results of different biomaterials used in sinus augmentation procedures: a human study at 6 months
Authors: Iezzi Giovanna , Degidi Marco , Piattelli Adriano , Mangano Carlo , Scarano Antonio , Shibli Jamil A. , Perrotti Vittoria
Published: November 2011

Objectives

Various grafts or combination of graft materials have been used in sinus floor augmentations, and human histological reports on their performance are available, although limited in number. Histological analysis of the regenerated tissues will provide useful information regarding the nature and amount of newly formed bone. Aim of the present study was a histological and histomorphometric evaluation, in humans, of specimens retrieved from sinuses augmented with phycogene hydroxyapatite, biphasic calcium phosphate ceramics, calcium carbonate, porcine bone and anorganic bovine bone, after a healing period of 6 months.

Materials and methods

A total of 15 patients, undergoing 30 sinus augmentation procedures with five different biomaterials, participated in this study. A total of 82 titanium dental implants were inserted in the augmented sinuses after a healing period of 6 months. A total of 60 bone cores, 2 for each augmented sinus, 12 for every biomaterial, were retrieved and all were stored immediately in 10% buffered formalin and processed to obtain thin ground sections.

Results

In all biomaterials, many grafted particles were lined and, sometimes, bridged by newly formed bone. Some biomaterials particles appeared to be partially resorbed and substituted by newly formed bone. Histomorphometry showed that, in all biomaterials, newly formed bone and residual grafted material particles represented about 30%.

Conclusions

Longer term histological and histomorphometric studies will be necessary to understand better the resorption times of all these biomaterials. The high interconnecting microporosity allowed, in all the present biomaterials, the ingrowth of newly formed bone and vessels in the pores of the partially resorbed particles. In conclusion, within the limitations of the present study, the data provided support the fact that all these biomaterials can be used, successfully, in sinus augmentation procedures.
Cognitive symptoms are common in immune thrombocytopenia and associate with autonomic symptom burden
Authors: Frith James , Watson Shirley , Maggs Paula H. B. Bolton , Newton Julia L.
Published: November 2011

Objectives:  People with adult immune thrombocytopenia (ITP) are commonly thought to have an isolated blood disorder, but many also describe memory and concentration problems. Cognitive impairment commonly associates with autonomic dysfunction. Here, we quantified cognitive symptoms in a large cohort of patients with ITP compared with controls and explored the relationship with autonomic symptoms.

Methods:  Patients with ITP were approached in the UK via the national ITP Support Association and invited to complete Composite Autonomic Symptom Scale (COMPASS; measure of autonomic symptoms) and Cognitive Failures Questionnaire (CFQ) together with one from a friend of similar age and sex without ITP.

Results:  Three hundred and ninety‐eight patients with ITP completed measures with paired data from a representative group of 189 patients and controls (47%). Both autonomic and cognitive symptom burden were higher in ITP compared with controls (COMPASS score (48 ± 14 vs. 38 ± 12; P > 0.0001); CFQ (43 ± 17 vs. 36 ± 13; P < 0.0001). A positive relationship was seen between increasing cognitive symptoms and higher COMPASS score (P < 0.0001; r2 = 0.1). Increasing cognitive symptoms did not associate with platelet count (P = 0.08, r2 = 0.008). Multivariate analysis confirmed age and COMPASS independently associated with higher CFQ but not platelet count.

Conclusions:  Immune thrombocytopenia is more than a bleeding disorder; cognitive symptoms are common and independently associate with autonomic symptoms but not disease severity.