bluuebunny/crossref_metadata_2025 huggingface dataset:
Multimodal imaging of mild traumatic brain injury and persistent postconcussion syndrome
Authors: Dean Philip J.A. , Sato Joao R. , Vieira Gilson , McNamara Adam , Sterr Annette
Published: December 2014

Background

Persistent postconcussion syndrome (PCS) occurs in around 5–10% of individuals after mild traumatic brain injury (mTBI), but research into the underlying biology of these ongoing symptoms is limited and inconsistent. One reason for this could be the heterogeneity inherent to mTBI, with individualized injury mechanisms and psychological factors. A multimodal imaging study may be able to characterize the injury better.

Aim

To look at the relationship between functional (fMRI), structural (diffusion tensor imaging), and metabolic (magnetic resonance spectroscopy) data in the same participants in the long term (>1 year) after injury. It was hypothesized that only those mTBI participants with persistent PCS would show functional changes, and that these changes would be related to reduced structural integrity and altered metabolite concentrations.

Methods

Functional changes associated with persistent PCS after mTBI (>1 year postinjury) were investigated in participants with and without PCS (both n = 8) and non‐head injured participants (n = 9) during performance of working memory and attention/processing speed tasks. Correlation analyses were performed to look at the relationship between the functional data and structural and metabolic alterations in the same participants.

Results

There were no behavioral differences between the groups, but participants with greater PCS symptoms exhibited greater activation in attention‐related areas (anterior cingulate), along with reduced activation in temporal, default mode network, and working memory areas (left prefrontal) as cognitive load was increased from the easiest to the most difficult task. Functional changes in these areas correlated with reduced structural integrity in corpus callosum and anterior white matter, and reduced creatine concentration in right dorsolateral prefrontal cortex.

Conclusion

These data suggest that the top‐down attentional regulation and deactivation of task‐irrelevant areas may be compensating for the reduction in working memory capacity and variation in white matter transmission caused by the structural and metabolic changes after injury. This may in turn be contributing to secondary PCS symptoms such as fatigue and headache. Further research is required using multimodal data to investigate the mechanisms of injury after mTBI, but also to aid individualized diagnosis and prognosis.
Adsorptive denitrogenation and desulfurization of diesel using activated carbons oxidized by (NH4)2S2O8 under mild conditions
Authors: Han Xue , Lin Hongfei , Zheng Ying
Published: December 2014

(NH4)2S2O8 solutions were applied to oxidize a wood‐based activated carbon (AC) under different conditions. Oxidation decreases the specific surface area of AC samples but increases the oxygen functional groups. Carboxylic acid groups and ketone groups may facilitate the adsorption of nitrogen (N) and sulfur (S) compounds in light cycled oil (LCO). An appropriate adsorbent was determined as the oxidized carbon which shows high N removal from LCO. The resultant adsorbent, AC‐(NH4)2S2O8‐15%‐1.5, exhibits higher adsorption capacities for N and S compounds than the original carbon in dynamic adsorption of a model diesel fuel. Carboxylic acid groups and lactone groups might favour quinoline adsorption. Carboxylic anhydride groups and phenolic groups are likely to improve the adsorption of indole, carbazole and dibenzothiophene (DBT). The thermodynamic and kinetic behaviours of AC‐(NH4)2S2O8‐15%‐1.5 were investigated. The adsorption of carbazole on AC‐(NH4)2S2O8‐15%‐1.5 follows the Langmuir model, while that of quinoline, indole and DBT follows the Freundlich model. All the adsorption processes are spontaneous, with the nature of adsorption for indole and carbazole endothermic, and that for quinoline and DBT exothermic. The adsorption of the N and S compounds in this study follows a pseudo second‐order model. Intra‐particle diffusion is one of the rate‐controlled steps for N compounds.
The Role of Therapist Attachment in Alliance and Outcome: A Systematic Literature Review
Authors: Degnan Amy , Seymour‐Hyde Annily , Harris Alison , Berry Katherine
Published: December 2014

Objectives

This review examined the impact of therapist attachment style on therapeutic alliance and outcomes.

Methods

Systematic search procedures yielded 11 studies for inclusion that measured associations between therapist attachment style and alliance and/or outcome.

Results

There is some preliminary evidence that therapist attachment style and interactions between therapist and client attachment style contribute to alliance and therapy outcomes. However, methodological weaknesses and heterogeneity across studies highlight the need for more rigorously designed research in this area.

Conclusions

There is sufficient evidence to suggest that therapists need to pay attention to the influence of their own attachment style in therapeutic processes and that there is merit in pursing this area of research further. The review is important in highlighting key design issues to consider in future studies. Copyright © 2014 John Wiley & Sons, Ltd.

Key Practitioner Message

Therapist attachment style has the potential to influence therapeutic alliance and client outcome.

Improvements in therapeutic practice might be achieved if therapists have greater knowledge of their own attachment styles and how these interact with their clients' attachment styles to influence the psychotherapy relationship and outcomes.

From the outset of their careers, therapists should receive training and supervision to enhance the awareness of their individual attachment experiences and how these play out during the therapeutic process.
Nobiletin Inhibits PDGF‐BB‐Induced Vascular Smooth Muscle Cell Proliferation and Migration and Attenuates Neointimal Hyperplasia in a Rat Carotid Artery Injury Model
Authors: Guan Siyu , Tang Qizhu , Liu Wenwei , Zhu Rui , Li Bin
Published: November 2014

Preclinical Research

The abnormal migration and proliferation of vascular smooth muscle cells (VSMCs) plays a pivotal role in the development of neointimal hyperplasia after vascular injury. Nobiletin, a citrus bioflavonoid, exhibits anti‐inflammatory and anti‐oxidative activities. The present study evalutaed whether nobiletin could inhibit platelet‐derived growth factor (PDGF)‐BB‐ stimulated VSMC proliferation and migration and decrease neointimal hyperplasia in a rat carotid artery injury model. Cultured VSMCs from rat thoracic aortas were treated with nobiletin before being stimulated with 20 ng/ml PDGF‐BB, and rats were subjected to carotid artery injury. Nobiletin inhibited PDGF‐BB‐induced VSMC proliferation and migration, attenuated reactive oxygen species (ROS) production and reduced phosphorylation of ERK1/2 and the expression of nuclear NF‐κB p65 in PDGF‐BB‐stimulated VSMCs. Nobiletin decreased the intima area and the ratio of neointima to media in balloon‐injured rat carotid arteries. Serum levels of TNF‐α and IL‐6 in nobiletin‐treated rats were decreased. These results indicated that nobiletin could be a potential protective agent for the prevention and treatment of restenosis after angioplasty.
Reconstruction of a windborne insect invasion using a particle dispersal model, historical wind data, andBayesian analysis of genetic data
Authors: Lander Tonya A. , Klein Etienne K. , Oddou‐Muratorio Sylvie , Candau Jean‐Noël , Gidoin Cindy , Chalon Alain , Roig Anne , Fallour Delphine , Auger‐Rozenberg Marie‐Anne , Boivin Thomas
Published: December 2014

Understanding how invasive species establish and spread is vital for developing effective management strategies for invaded areas and identifying new areas where the risk of invasion is highest. We investigated the explanatory power of dispersal histories reconstructed based on local‐scale wind data and a regional‐scale wind‐dispersed particle trajectory model for the invasive seed chalcid waspMegastigmus schimitscheki(Hymenoptera: Torymidae) in France. The explanatory power was tested by: (1) survival analysis of empirical data onM. schimitschekipresence, absence and year of arrival at 52 stands of the wasp's obligate hosts,Cedrus(true cedar trees); and (2) Approximate Bayesian analysis ofM. schimitschekigenetic data using a coalescence model. The Bayesian demographic modeling and traditional population genetic analysis suggested that initial invasion across the range was the result of long‐distance dispersal from the longest established sites. The survival analyses of the windborne expansion patterns derived from a particle dispersal model indicated that there was an informative correlation between theM. schimitschekipresence/absence data from the annual surveys and the scenarios based on regional‐scale wind data. These three very different analyses produced highly congruent results supporting our proposal that wind is the most probable vector for passive long‐distance dispersal of this invasive seed wasp. This result confirms that long‐distance dispersal from introduction areas is a likely driver of secondary expansion of alien invasive species. Based on our results, management programs for this and other windborne invasive species may consider (1) focusing effort at the longest established sites and (2) monitoring outlying populations remains critically important due to their influence on rates of spread. We also suggest that there is a distinct need for new analysis methods that have the capacity to combine empirical spatiotemporal field data, genetic data, and environmental data to investigate dispersal and invasion.
Homometallic FeIII4 and Heterometallic {FeIII4LnIII2} (Ln = Dy, Tb) Complexes – Syntheses, Structures, and Magnetic Properties
Authors: Goura Joydeb , Mereacre Valeriu , Novitchi Ghenadie , Powell Annie K. , Chandrasekhar Vadapalli
Published: December 2014

The sequential reaction of the multisite coordination ligand 2‐methoxy‐6‐{[2‐(2‐hydroxyethylamino)ethylimino]methyl}phenol (LH2) with Fe(ClO4)2·4H2O or a combination of Fe(ClO4)2·4H2O and Ln(NO3)3·5H2O [DyIII and TbIII] in the presence of tetramethylammonium hydroxide and pivalic acid (pivH) under ambient conditions afforded a homometallic tetranuclear FeIII complex and heterometallic hexanuclear FeIII/LnIII complexes, namely, [Fe4(μ3‐O)2(L)4]·3CH3CN·2CH3OH (1), [Fe4Dy2(μ3‐O)2(L)2(O2CCMe3)10(MeOH)]·2CH3CN (2), and [Fe4Tb2(μ3‐O)2(L)2(O2CCMe3)10(HO2CCMe3)]·H2O (3). Compounds 1–3 crystallize in the monoclinic system in space group P21/n (Z = 4). The homometallic tetranuclear derivative 1 possesses three contiguous four‐membered Fe2O2 rings in a ladderlike configuration. Each of the iron centers is hexacoordinate (2N, 4O) in a distorted octahedral geometry. On the other hand, 2 and 3 contain two symmetrically related Fe2Ln units that are joined to each other through oxygen atoms from the ethoxide side arms of the ligand L2–; the two lanthanide ions are located at the opposite ends of the hexanuclear core. In 2 and 3, the lanthanide centers are eight‐ (distorted trigonal dodecahedron) and nine‐coordinate (distorted monocapped square antiprism), respectively, and the iron centers are hexacoordinate (distorted octahedral). Magnetic studies on 2 and 3 reveal the presence of weak antiferromagnetic coupling between the FeIII and LnIII ions.
Synthesis and Stability of Nucleoside 3′,5′‐Cyclic Phosphate Triesters Masked with Enzymatically and Thermally Labile Phosphate Protecting Groups
Authors: Sontakke Vyankat A. , Shinde Vaishali S. , Lönnberg Harri , Ora Mikko
Published: December 2014

Appropriately protected structurally modified nucleoside 3′,5′‐cyclic monophosphates are known to show antiviral activity. For this reason, a straightforward synthesis of nucleoside 3′,5′‐cyclic phosphates protected with three different enzymatically removable groups, viz. 3‐acetyloxy‐2,2‐bis(ethoxycarbonyl)propyl (in 1 and 4), 4‐acetylthio‐2,2‐dimethyl‐3‐oxobutyl (in 2), and 4‐(tert‐butyldisulfanyl)‐2,2‐dimethyl‐3‐oxobutyl (in 3) groups, is described. Removal of these protecting groups at pH 7.5 and 37 °C was monitored by reverse‐phase HPLC.
Rising stars: Modulation of brain functions by astroglial type‐1 cannabinoid receptors
Authors: Metna‐Laurent Mathilde , Marsicano Giovanni
Published: December 2014

The type‐1‐cannabinoid (CB1) receptor is amongst the most widely expressed G protein‐coupled receptors in the brain. In few decades, CB1 receptors have been shown to regulate a large array of functions from brain cell development and survival to complex cognitive processes. Understanding the cellular mechanisms underlying these functions of CB1 is complex due to the heterogeneity of the brain cell types on which the receptor is expressed. Although the large majority of CB1 receptors act on neurons, early studies pointed to a direct control of CB1 receptors over astroglial functions including brain energy supply and neuroprotection. In line with the growing concept of the tripartite synapse highlighting astrocytes as direct players in synaptic plasticity, astroglial CB1 receptor signaling recently emerged as the mediator of several forms of synaptic plasticity associated to important cognitive functions. Here, we shortly review the current knowledge on CB1 receptor‐mediated astroglial functions. This functional spectrum is large and most of the mechanisms by which CB1 receptors control astrocytes, as well as their consequences in vivo, are still unknown, requiring innovative approaches to improve this new cannabinoid research field. GLIA 2015;63:353–364
Numerical Analysis of Turbulent Forced Convection of Nanofluid Flow over a Heated Shallow Cavity
Authors: Abdellahoum Chahrazed , Mataoui Amina
Published: December 2014

This work presents a numerical investigation of turbulent forced convection of a nanofluid over a heated cavity in a horizontal duct. Heat transfers in separated flows are frequently encountered in engineering applications, such as: heat exchangers, axial and centrifugal compressor blades, gas turbines blades, and microelectronic circuit boards. Thus, it is very essential to understand the mechanisms of heat transfer in such regions in order to enhance heat transfer. Different volume fractions of nanoparticles are presented in the base fluid and different types of nanoparticles are used. The objective of this study is to check the effect of nanofluid on heat transfer in such a configuration. Numerical simulations are performed for pure water and four nanofluids (Cu, CuO, Ag, and Al2O3). The results are analyzed through the thermal and dynamical fields with a particular interest to the skin friction coefficient and Nusselt number evolutions. The average Nusselt number increases with the volume fraction of nanoparticles for the whole tested range of Reynolds number. A correlation of average Nusselt number versus Reynolds number and volume fraction of each type of nanoparticles over the cavity wall is proposed in this paper.
Synthesis of Block Copolymers Containing Polybutadiene Segments by Combination of Coordinative Chain Transfer Polymerization, Ring‐Opening Polymerization, and Atom Transfer Radical Polymerization
Authors: Wang Feng , Dong Bo , Liu Heng , Guo Jun , Zheng Wenjie , Zhang Chunyu , Zhao Liping , Bai Chenxi , Hu Yanming , Zhang Xuequan
Published: November 2014

Two triblock copolymers, polybutadiene‐block‐poly(ε‐caprolactone)‐block‐poly(methyl methacrylate) (PBD‐b‐PCL‐b‐PMMA) and polybutadiene‐block‐poly(ε‐caprolactone)‐block‐polystyrene (PBD‐b‐PCL‐b‐PS), are synthesized by combination of coordinative chain transfer polymerization (CCTP), ring‐opening polymerization (ROP), and atom transfer radical polymerization (ATRP). The molecular structures of these polymers are determined by 1H NMR and gel‐permeation chromatography (GPC) analysis. The resulting triblock copolymers are evaluated as compatibilizing agents for highly immiscible binary PBD/PMMA and PBD/PS blends. The presence of these compatibilizers substantially reduces the average PMMA or PS droplet size. Furthermore, static water contact angle experiments are employed to assess the modification of the surface properties of nonpolar PBD.

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Comparison of results obtained with standard and inside out vein graft techniques and their implication on neurotrophin expression in repair of nerve defect: An experimental study
Authors: Ahmed Farooque Jamaluddin , Junior Geraldo Marco Rosa , Shinohara Andre Luis , De Souza Melo Carina Guimaraes , Buchaim Rogerio Leone , Andreo Jesus Carlos , De Castro Rodrigues Antonio
Published: November 2014

Standard vein graft (SVG) and inside out vein graft (IOVG) techniques to promote peripheral nerve regeneration have been widely studied since last two decades. In this experimental study, we attempted to compare these two techniques and analyze the differences in the expression of the neurotrophins during peripheral nerve regeneration. Thirty‐six male Wistar rats were used in this sciatic nerve transection model and were divided into two experimental groups (SVG and IOVG) and one sham operated control group. An overall defect of 10 mm was made in the sciatic nerve of the animals in the experimental groups. Each group consisted of two time intervals of 6 and 12 weeks (n = 6). After each experimental interval, sciatic functional index (SFI) along with area and diameter of the axons and fibers of each group were calculated. Muscle mass measurements were also evaluated to see any functional recovery in the groups. Expression of neurotrophins in the graft and distal stump were analyzed with the help of RT‐PCR. SFI obtained from walking track analysis showed poor motor recovery in the experimental groups during both time intervals. No significant differences in the histological, morphometric (P > 0.05), and muscle mass measurements (P > 0.05) between the two experimental groups were observed. Analysis of RT‐PCR data exhibited an increase in the expression of NT‐3 with time in both the grafts (6 weeks 0.428 ± 0.392, 12 weeks 1.089 ± 0.455, P < 0.05) and distal stump (6 weeks 0.411 ± 0.306, 12 weeks 0.807 ± 0.303, P < 0.05) of the SVG group. The study concludes that there is no substantial difference in the nerve regeneration ability between both the techniques. Also, the difference in the level of NT‐3 between SVG and IOVG suggests a distinct regulation of NT‐3 in peripheral nerve regeneration. © 2014 Wiley Periodicals, Inc. Microsurgery 35:227–234, 2015.
A numerical power spectrum for electroencephalographic processing
Authors: Navascués M. A. , Sebastián M. V. , Ruiz C. , Iso J. M.
Published: December 2014

The record of the oscillations of the electric potential of the human brain provides useful information about the mind activity at rest and during the achievement of sensory and cognitive processing tasks. The use of appropriate quantitative tools assigning numerical values to the observed variable is necessary to define good descriptors of the electroencephalogram, allowing comparisons between different recordings. In this line, we propose a numerical method for the spectral and temporal reconstruction of a brain signal. The convergence of the procedure is analyzed, providing results of the concerned approximation error. In a second part of the text, we use the methodology described to the quantification of the bioelectric variations produced in the brain waves for the execution of a test of attention related to military simulation. Copyright © 2014 JohnWiley & Sons, Ltd.
On a multidimensional model for the codiffusion of isotopes: existence and uniqueness
Authors: Comparini E. , Ughi M.
Published: December 2014

The paper deals with the existence and uniqueness of classical solutions of the homogeneous Neumann problem for a class of parabolic–hyperbolic system of partial differential equations in n dimensions. The problem arises from a model of the diffusion of N species of radioactive isotopes of the same element. Copyright © 2014 John Wiley & Sons, Ltd.
Modified equations of the first kind for the Helmholtz equation
Authors: Thomson G. R.
Published: December 2014

Integral equations of the first kind for exterior problems arising in the study of the three‐dimensional Helmholtz equation are considered. These equations are derived by seeking solutions in the form of layer potentials with modified fundamental solutions. For each first kind equation, existence and uniqueness of solution are proved with the aid of composition relations involving associated modified boundary integral operators. For the Dirichlet problem, an optimal choice of the modification coefficients is considered in order to minimize the condition number of the resulting integral operator. Copyright © 2014 John Wiley & Sons, Ltd.
The hemoglobin values of Korean adolescents show distinctive characteristics in comparison to those of Caucasians and African Americans
Authors: Lim Jung Sub , Seo Ju‐Hee , Kim Dong Ho , Lee Jun Ah
Published: December 2014

Background

Hematologic reference values vary by ethnicity. We aimed to determine reference values of hemoglobin (Hb) for Korean adolescents.

Methods

Using data from the 5th Korean National Health and Nutrition Examination Survey (KNHANES), we obtained reference values for Hb in adolescents aged 10–20 years.

Results

Among 2,526 subjects recruited, 330 were excluded due to chronic diseases (9 congenital heart disease, 6 epilepsy, and 1 thyroid disease) or abnormal laboratory values (253 subjects with Fe/TIBC <16%, 103 subjects with MCV <80 fl). Accordingly, data from 2,196 subjects (male = 1,196 and female = 1,000) were analyzed and age‐ and gender‐stratified means and percentile values of Hb were obtained. Pertinent findings observed in the current study were: (i) Hb levels in Korean male were similar to those of non‐Hispanic Caucasians; (ii) Hb values in females were similar to those of non‐Hispanic Caucasians until age of 15, and thereafter were slightly lower. Prevalence of anemia according to WHO criteria and our own criteria (Hb levels <2 standard deviations of age‐ and gender‐specific values) in total sample was 3.5% (88/2,526) and 3.8% (97/2,526), respectively. Anemia was more prevalent in female in comparison with male (6.5% vs. 1.0%, P < 0.001).

Conclusions

Our results could be used as a national reference standard to correctly classify a large population sample. Further studies are necessary to determine reference Hb values for children younger than 10 years and identify genetic variations associated with distinctive characteristics observed in this study. Pediatr Blood Cancer 2015;62:409–413. © 2014 Wiley Periodicals, Inc.
Hydrogen bond containing multiwalled carbon nanotubes in polyurethane composites
Authors: Inglefield David L. , Bodnar Robert J. , Long Timothy E.
Published: November 2014

Introduction of hydrogen bonding sites onto multi‐walled carbon nanotubes (MWCNTs) included carboxylic acid, amide‐amine, and novel amide‐urea MWCNTs for the formation of homogenous polyurethane composites. Acid oxidation and subsequent derivatization introduced hydrogen bonding functionality onto MWCNTs to reveal the effect of surface functionalization on mechanical properties in a 45 wt% hard segment polyurethane matrix. Raman spectroscopy showed an increase in the D/G peak ratio, which indicated successful oxidation, and X‐ray photoelectron spectroscopy also revealed elemental compositions that supported each step of the functionalization strategy. Thermogravimetric analysis supported functionalization with an increase in percent weight loss for each functionalization, and the MWCNT surface functionalization determined pH‐dependent dispersibility. The nonfunctionalized MWCNT composites showed poor dispersion with transmission electron microscopy, and in sharp contrast, the functionalized composites displayed homogenous dispersions. Tensile testing revealed improved stress at break in the functionalized MWCNT composites at low loadings due to homogenous dispersion. POLYM. COMPOS., 37:1425–1434, 2016. © 2014 Society of Plastics Engineers
Circulating cell free DNA testing: are some test failures informative?
Authors: Palomaki G. E. , Kloza E. M. , Lambert‐Messerlian G. M. , van den Boom D. , Ehrich M. , Deciu C. , Bombard A. T. , Haddow J. E.
Published: December 2014

Objective

The proportion of circulating cell free DNA derived from the feto‐placental unit (fetal fraction or FF) correlates with test success and interpretation reliability. Some fetal disorders are associated with systematically lower FF, sometimes resulting in noninformative results.

Methods

We analyzed results from pregnancies tested in a nested case/control study derived from a cohort of 4664 high‐risk pregnancies. Low FF was defined before and after adjusting for maternal weight and gestational age.

Results

Compared with euploid pregnancies, the median FF was significantly higher in Down syndrome pregnancies (ratio 1.17) and significantly lower in trisomy 18 and triploid pregnancies (ratios 0.71 and 0.19, respectively). Among 2157 pregnancies tested, 13 (0.6%) had FF <3.0% (all noninformative), including three trisomy 18 and three triploidy fetuses. After adjustment, 16 pregnancies (0.7%) had FF <0.3 multiples of the median (six informative), including one trisomy 18 and three triploidy fetuses. Modeled positive predictive values for low and high‐risk populations were 7% and 30%, respectively.

Conclusion

Among women with noninformative results attributable to low FF, trisomy 18 and/or triploidy risk are sufficiently high to warrant offering additional assessments (e.g. ultrasound). If the testing indication is ultrasound abnormality, amniocentesis and karyotype/microarray should be considered. © 2014 John Wiley & Sons, Ltd.
Feedback Received While Practicing Everyday Activities During Rehabilitation After Stroke: An Observational Study
Authors: Stanton Rosalyn , Ada Louise , Dean Catherine M. , Preston Elisabeth
Published: December 2014

Background and Purpose

The provision of feedback is important for effective skill learning. The purpose of this study was to examine the nature of feedback provided during the practice of everyday activities (such as standing up, walking, and reaching and grasping objects) during stroke rehabilitation, both when the therapist was present and when the patient was practicing alone.

Method

Design: A cross‐sectional observational study of the feedback received during rehabilitation by people who had had a stroke was conducted. Forty unique patient–therapist dyads were observed during 30 minutes of actual practice of everyday activities with data collected through behavioural mapping. The following was recorded: the activity practiced, whether the therapist was present, whether feedback was provided verbally or by equipment, and the content of feedback. Participants: A sample of all therapists providing rehabilitation within one Australian health service and their patients who had had a stroke. Measures: Quantity, frequency, mode (verbal or equipment) and content (information feedback, motivational statements, unrelated or none) of feedback during the practice of everyday activities were determined.

Results

For 68% of the time that patients were practicing activities, they received ≥1 occasion of feedback/minute. When the therapist was present, the frequency of motivational statements was more than four times greater, at 1.32 (SD 0.6) occasions/minute, than information feedback. For 25% of the time, the therapist was not present, and no feedback was provided.

Conclusion

Given the importance of specific content for learning, therapists could replace some motivational statements with information feedback. When practicing alone, information feedback could be provided by commercially available biofeedback or customized equipment. Copyright © 2014 John Wiley & Sons, Ltd.
A moonlighting function of Mycobacterium smegmatis Ku in zinc homeostasis?
Authors: Kushwaha Ambuj K. , Deochand Dinesh K. , Grove Anne
Published: November 2014

Ku protein participates in DNA double‐strand break repair via the nonhomologous end‐joining pathway. The three‐dimensional structure of eukaryotic Ku reveals a central core consisting of a β‐barrel domain and pillar and bridge regions that combine to form a ring‐like structure that encircles DNA. Homologs of Ku are encoded by a subset of bacterial species, and they are predicted to conserve this core domain. In addition, the bridge region of Ku from some bacteria is predicted from homology modeling and sequence analyses to contain a conventional HxxC and CxxC (where x is any residue) zinc‐binding motif. These potential zinc‐binding sites have either deteriorated or been entirely lost in Ku from other organisms. Using an in vitro metal binding assay, we show that Mycobacterium smegmatis Ku binds two zinc ions. Zinc binding modestly stabilizes the Ku protein (by ∼3°C) and prevents cysteine oxidation, but it has little effect on DNA binding. In vivo, zinc induces significant upregulation of the gene encoding Ku (∼sixfold) as well as a divergently oriented gene encoding a predicted zinc‐dependent MarR family transcription factor. Notably, overexpression of Ku confers zinc tolerance on Escherichia coli. We speculate that zinc‐binding sites in Ku proteins from M. smegmatis and other mycobacterial species have been evolutionarily retained to provide protection against zinc toxicity without compromising the function of Ku in DNA double‐strand break repair.
HONPAS: A linear scaling open‐source solution for large system simulations
Authors: Qin Xinming , Shang Honghui , Xiang Hongjun , Li Zhenyu , Yang Jinlong
Published: December 2014

HONPAS is an ab initio electronic structure program for linear scaling or O(N) first‐principles calculations of large and complex systems using standard norm‐conserving pseudopotentials, numerical atomic orbitals (NAOs) basis sets, and periodic boundary conditions. HONPAS is developed in the framework of the SIESTA methodology and focuses on the development and implementation of efficient O(N) algorithms for ab initio electronic structure calculations. The Heyd–Scuseria–Ernzerhof (HSE) screened hybrid density functional has been implemented using a NAO2GTO scheme to evaluate the electron repulsion integrals (ERIs) with NAOs. ERI screening techniques allow the HSE functional calculations to be very efficient and scale linearly. The density matrix purification algorithms have been implemented, and the PSUTC2 and SUTC2 methods have been developed to deal with spin unrestricted systems with or without predetermined spin multiplicity, respectively. After the self‐consistent field (SCF) process, additional O(N) post‐SCF calculations for frontier molecular orbitals and maximally localized Wannier functions are also developed and implemented. Finally, an O(N) method based on the density matrix perturbation theory has been proposed and implemented to treat electric field in solids. This article provides an overall introduction to capabilities of HONPAS and implementation details of different O(N) algorithms. © 2014 Wiley Periodicals, Inc.
On the isobaric space of 25‐hydroxyvitamin D in human serum: potential for interferences in liquid chromatography/tandem mass spectrometry, systematic errors and accuracy issues
Authors: Qi Yulin , Geib Timon , Schorr Pascal , Meier Florian , Volmer Dietrich A.
Published: December 2014

RATIONALE

Isobaric interferences in human serum can potentially influence the measured concentration levels of 25‐hydroxyvitamin D [25(OH)D], when low resolving power liquid chromatography/tandem mass spectrometry (LC/MS/MS) instruments and non‐specific MS/MS product ions are employed for analysis. In this study, we provide a detailed characterization of these interferences and a technical solution to reduce the associated systematic errors.

METHODS

Detailed electrospray ionization Fourier transform ion cyclotron resonance (FTICR) high‐resolution mass spectrometry (HRMS) experiments were used to characterize co‐extracted isobaric components of 25(OH)D from human serum. Differential ion mobility spectrometry (DMS), as a gas‐phase ion filter, was implemented on a triple quadrupole mass spectrometer for separation of the isobars.

RESULTS

HRMS revealed the presence of multiple isobaric compounds in extracts of human serum for different sample preparation methods. Several of these isobars had the potential to increase the peak areas measured for 25(OH)D on low‐resolution MS instruments. A major isobaric component was identified as pentaerythritol oleate, a technical lubricant, which was probably an artifact from the analytical instrumentation. DMS was able to remove several of these isobars prior to MS/MS, when implemented on the low‐resolution triple quadrupole mass spectrometer.

CONCLUSIONS

It was shown in this proof‐of‐concept study that DMS‐MS has the potential to significantly decrease systematic errors, and thus improve accuracy of vitamin D measurements using LC/MS/MS. Copyright © 2014 John Wiley & Sons, Ltd.
New insights into dissociation of deprotonated 2,4‐dinitrotoluene by combined high‐resolution mass spectrometry and density functional theory calculations
Authors: Schwarzenberg Adrián , Tabet Jean‐Claude , Cole Richard B. , Machuron‐Mandard Xavier , Dossmann Héloïse
Published: December 2014

RATIONALE

2,4‐Dinitrotoluene (2,4‐DNT) is a nitroaromatic explosive which is commonly found in environmental samples close to training points, firing places, and manufacturers. Mass spectrometry analysis of this compound shows one main product ion that distinguishes it from the other isomers of DNT. We present here a detailed mechanistic study on the formation of this ion.

METHODS

2,4‐DNT was analyzed using negative electrospray ionization high‐resolution mass spectrometry (ESI‐HRMS) using a linear ion trap quadrupole LTQ‐Orbitrap XL mass spectrometer. Collision‐induced dissociation (CID) experiments were performed on the [M–H]– ion obtained. Density functional theory (DFT) calculations were used to support experimental observations.

RESULTS

Fragmentation of deprotonated 2,4‐DNT [M–H]– (m/z 181) yields a main product ion at m/z 116. The mechanism of formation of this diagnostic product ion is not obvious and it has never been rationalized. Calculations were performed to probe different mechanistic variants, which are discussed in this work.

CONCLUSIONS

Analysis of possible pathways to form the m/z 116 ion from the m/z 181 precursor shows that its formation is likely to proceed first via NO• loss, followed by eliminations of H2O and then HO•. Copyright © 2014 John Wiley & Sons, Ltd.
The benefits and limitations of reaction cell and sector field inductively coupled plasma mass spectrometry in the detection and quantification of phosphopeptides
Authors: Maes Evelyne , Brusten Wilfried , Beutels Filip , Baggerman Geert , Mertens Inge , Valkenborg Dirk , Landuyt Bart , Schoofs Liliane , Tirez Kristof
Published: December 2014

RATIONALE

The phosphorylation of proteins is one of the most important post‐translational modifications in nature. Knowledge of the quantity or degree of protein phosphorylation in biological samples is extremely important. A combination of liquid chromatography (LC) and inductively coupled plasma mass spectrometry (ICP‐MS) allows the absolute and relative quantification of the phosphorus signal.

METHODS

A comparison between dynamic reaction cell quadrupole ICP‐MS (DRC‐Q‐ICP‐MS) and high‐resolution sector field ICP‐MS (SF‐ICP‐MS) in detecting signals of phosphorus‐containing species using identical capillary LC (reversed‐phase technology) and nebulizer settings was performed.

RESULTS

A method to diminish the reversed‐phase gradient‐related signal instability in phosphorus detection with LC/ICP‐MS applications was developed. Bis(4‐nitrophenyl)phosphate (BNPP) was used as a standard to compare signal‐to‐noise ratios and limits of detection (LODs) between the two instrumental setups. The LOD reaches a value of 0.8 µg L−1 when applying the DRC technology in Q‐ICP‐MS and an LOD of 0.09 µg L−1 was found with the SF‐ICP‐MS setup. This BNPP standard was further used to compare the absolute quantification possibilities of phosphopeptides in these two setups.

CONCLUSIONS

This one‐to‐one comparison of two interference‐reducing ICP‐MS instruments demonstrates that absolute quantification of individual LC‐separated phosphopeptides is possible. However, based on the LOD values, SF‐ICP‐MS has a higher sensitivity in detecting phosphorus signals and thus is preferred in phosphopeptide analysis. Copyright © 2014 John Wiley & Sons, Ltd.
Detection of 135Cs by accelerator mass spectrometry
Authors: MacDonald C. , Charles C. R. J. , Cornett R. J. , Zhao X. L. , Kieser W. E. , Litherland A. E.
Published: December 2014

RATIONALE

The ability to measure both 135Cs and 137Cs can provide an estimate of the age and source of Cs isotopes in an environmental sample. Accelerator mass spectrometry (AMS) consistently reports lower abundance sensitivities than other techniques and, with the addition of an on‐line reaction cell, simpler isobaric suppression. Therefore, an AMS methodology was developed to measure Cs isotopes using Cs as the initial anion.

METHODS

The ion beam is passed through the Isobar Separator for Anions (ISA) where it is captured by radiofrequency quadrupoles in a gas cell before injection into the tandem accelerator. In the ISA, the beam reacts with O2 gas, selectively removing the Ba and leaving the Cs analyte to be reaccelerated and sent through the remainder of the AMS system.

RESULTS

The Ba signal was attenuated by a factor of 105 in the ISA while 25% of the original Cs current was transmitted into the accelerator. 135Cs was measured without any interference from 133Cs to an abundance sensitivity of 1.3 × 10–10. The abundances of four stable Ba isotopes (masses 133, 134, 135 and 137) were measured and no isotope‐dependent bias was detected using the ISA in vacuum.

CONCLUSIONS

The results demonstrate the feasibility of measuring long‐lived Cs isotopes without Ba interference by AMS with on‐line isobar separation and the ability to use shorter lived Cs isotopes for yield tracing. Copyright © 2014 John Wiley & Sons, Ltd.
Gas chromatography with parallel hard and soft ionization mass spectrometry
Authors: Hejazi Leila , Guilhaus Michael , Hibbert D. Brynn , Ebrahimi Diako
Published: December 2014

RATIONALE

Mass spectrometric identification of compounds in chromatography can be obtained from molecular masses from soft ionization mass spectrometry techniques such as field ionization (FI) and fragmentation patterns from hard ionization techniques such as electron ionization (EI). Simultaneous detection by EI and FI mass spectrometry allows alignment of the different information from each method.

METHODS

We report the construction and characteristics of a combined instrument consisting of a gas chromatograph and two parallel mass spectrometry ionization sources, EI and FI. When considering both ion yield and signal‐to‐noise it was postulated that good‐quality EI and FI mass spectra could be obtained simultaneously using a post‐column splitter with a split fraction of 1:10 for EI/FI. This has been realised and we report its application for the analysis of several complex mixtures.

RESULTS

The differences between the full width at half maximum (FWHM) of the EI and FI chromatograms were statistically insignificant, and the retention times of the chromatograms were highly correlated (r2 =0.9999) with no detectable bias. The applicability and significance of this combined instrument and the attendant methodology are illustrated by the analysis of standard samples of 13 compounds with diverse structures, and the analysis of mixtures of fatty acids, fish oil, hydrocarbons and yeast metabolites.

CONCLUSIONS

This combined dual‐source instrument saves time and resources, and more importantly generates equivalent chromatograms aligned in time, in EI and FI (i.e. peaks with similar shapes and identical positions). The identical FWHMs and retention times of the EI and FI chromatograms in this combined instrument enable the accurate assignment of fragment ions from EI to their corresponding molecular ions in FI. Copyright © 2014 John Wiley & Sons, Ltd.
Genetically Induced Cell Death in Bulge Stem Cells Reveals Their Redundancy for Hair and Epidermal Regeneration
Authors: Driskell Iwona , Oeztuerk-Winder Feride , Humphreys Peter , Frye Michaela
Published: December 2014

Adult mammalian epidermis contains multiple stem cell populations in which quiescent and more proliferative stem and progenitor populations coexist. However, the precise interrelation of these populations in homeostasis remains unclear. Here, we blocked the contribution of quiescent keratin 19 (K19)-expressing bulge stem cells to hair follicle formation through genetic ablation of the essential histone methyltransferase Setd8 that is required for the maintenance of adult skin. Deletion of Setd8 eliminated the contribution of bulge cells to hair follicle regeneration through inhibition of cell division and induction of cell death, but the growth and morphology of hair follicles were unaffected. Furthermore, ablation of Setd8 in the hair follicle bulge blocked the contribution of K19-postive stem cells to wounded epidermis, but the wound healing process was unaltered. Our data indicate that quiescent bulge stem cells are dispensable for hair follicle regeneration and epidermal injury in the short term and support the hypothesis that quiescent and cycling stem cell populations are equipotent. Stem Cells  2015;33:988–998
AdS6 solutions of type II supergravity
Authors: Apruzzi Fabio , Fazzi Marco , Passias Achilleas , Rosa Dario , Tomasiello Alessandro
Published: December 2014

Abstract

Very few AdS6 × M4 supersymmetric solutions are known: one in massive IIA, and two IIB solutions dual to it. The IIA solution is known to be unique; in this paper, we use the pure spinor approach to give a classification for IIB supergravity. We reduce the problem to two PDEs on a two-dimensional space Σ. M4 is then a fibration of S2 over Σ; the metric and fluxes are completely determined in terms of the solution to the PDEs. The results seem likely to accommodate near-horizon limits of (p, q)-fivebrane webs studied in the literature as a source of CFT5’s. We also show that there are no AdS6 solutions in eleven-dimensional supergravity.
Testing electroweak baryogenesis with future colliders
Authors: Curtin David , Meade Patrick , Yu Chiu-Tien
Published: December 2014

Abstract

Electroweak Baryogenesis (EWBG) is a compelling scenario for explaining the matter-antimatter asymmetry in the universe. Its connection to the electroweak phase transition makes it inherently testable. However, completely excluding this scenario can seem difficult in practice, due to the sheer number of proposed models. We investigate the possibility of postulating a “no-lose” theorem for testing EWBG in future e
+
e
− or hadron colliders. As a first step we focus on a factorized picture of EWBG which separates the sources of a stronger phase transition from those that provide new sources of CP violation. We then construct a “nightmare scenario” that generates a strong first-order phase transition as required by EWBG, but is very difficult to test experimentally. We show that a 100 TeV hadron collider is both necessary and possibly sufficient for testing the parameter space of the nightmare scenario that is consistent with EWBG.
Super-Rényi entropy & Wilson loops for $$ \mathcal{N}=4 $$ SYM and their gravity duals
Authors: Crossley Michael , Dyer Ethan , Sonner Julian
Published: December 2014

Abstract

We compute the supersymmetric Rényi entropies across a spherical entanglement surface in

$$ \mathcal{N}=4 $$

N
=
4

SU(N) SYM theory using localization on the four-dimensional ellipsoid. We extract the leading result at large N and λ and match its universal part to a gravity calculation involving a hyperbolically sliced supersymmetric black hole solution of

$$ \mathcal{N}={4}^{+} $$

N
=

4
+

SU(2) × U(1) gauged supergravity in five dimensions. We repeat the analysis in the presence of a Wilson loop insertion and find again a perfect match with the dual string theory. Understanding the Wilson loop operator requires knowledge of the full ten-dimensional IIB supergravity solution which we elaborate upon.
The Impact of Anastomotic Leak and Its Treatment on Cancer Recurrence and Survival Following Elective Colorectal Cancer Resection
Authors: Nachiappan Subramanian , Askari Alan , Malietzis George , Giacometti Marco , White Ian , Jenkins John T. , Kennedy Robin H. , Faiz Omar
Published: December 2014

Aim

Anastomotic leakage is a serious complication in restorative colorectal surgery. Anastomotic leakage and its subsequent management may have long‐term impact on survival. This study aims to assess the impact of colorectal anastomotic leak (AL) on overall survival (OS) and disease‐free survival (DFS).

Methods

A prospective database of 1,048 patients undergoing restorative colorectal cancer resections at St Mark’s hospital between October 2004 and October 2013 was examined.

Results

The overall leak rate was 99/1,048 (9.4 %). 43 ALs were managed conservatively with antibiotics or radiological drainage and 56 with reoperations. OS was significantly reduced in the AL group treated with a reoperation (HR 2.74, 95 % CI 1.67–4.52, p < 0.001). AL was not significantly associated with worse DFS [conservatively managed AL’s vs. no AL—HR 2.07 (95 % CI 1.05–4.10); reoperated AL’s vs. no AL—HR 1.56 (95 % CI 0.81–2.99), overall p value = 0.058].

Conclusion

Patients who suffer anastomotic leaks requiring reoperations have worse OS compared to patients who do not leak, but there were no significant differences in DFS between patients who leaked and those who did not.
Natural licks are required for large terrestrial mammals in a degraded riparian forest, Sabah, Borneo, Malaysia
Authors: Matsuda Ikki , Ancrenaz Marc , Akiyama Yoshihiro , Tuuga Augustine , Majalap Noreen , Bernard Henry
Published: December 2014

Although the importance of natural licks for terrestrial mammals is widely acknowledged, we report here for the first time its importance for large terrestrial mammals in a degraded riverine forest in Borneo. Our results clearly demonstrated that various mammals, including bearded pig, sambar deer, and endangered orang‐utans, were using the natural lick, though large arboreal/avian herbivore/omnivore animals were not attracted to the natural lick. In addition, the diversity of mammal species recorded in this study was lower than those recorded in the dry lowland forest. Possible reasons for this difference between the different forest types are discussed.
Effects of internal conductance and Rubisco on the optimum temperature for leaf photosynthesis in Fallopia japonica growing at different altitudes
Authors: Sakata Tsuyohi , Nakano Takashi , Kachi Naoki
Published: December 2014

To investigate mechanisms of adjustment of the optimum temperature for leaf photosynthesis in alpine plants, we compared the temperature responses of photosynthesis, internal conductance (gi), and the amounts of activated Rubisco (ε) in two Fallopia japonica populations growing at elevations of 100 m (K0100), and 2250 m (F2250). There was an obvious difference in photosynthesis at high temperatures between the two populations, although there was no significant difference in the CO2/O2 specificity of Rubisco. Optimum temperatures for photosynthesis were 25 and 30 °C in F2250 and K0100, respectively. The temperature response of ε was similar to that of photosynthesis. The mean values of ε decreased 25 % (F2250) and 24 % (K0100), for temperatures 5 °C above the optimum for photosynthesis. In contrast, gi exponentially increased with increasing temperature in both populations. There was no significant difference in gi between populations for any given temperature. In both populations, there were no changes in CO2 concentrations at the Rubisco active site, when temperatures were above the photosynthetic optimum temperature. This clearly shows that photosynthetic optimum temperatures were not affected by photosynthetic limitation of CO2 diffusing from intercellular air spaces to Rubisco. Furthermore, the atmospheric pressure had a minor effect on the temperature response of photosynthesis. Thus, the decrease in ε in response to elevated temperatures reduced the photosynthetic optimum temperature in highland population of F. japonica, which was adjusted to the habitat.