bluuebunny/crossref_metadata_2025_split huggingface dataset:
Needlestick injuries at a tertiary teaching hospital in Singapore
Authors: SENG M. , SNG G. K. J. , ZHAO X. , VENKATACHALAM I. , SALMON S. , FISHER D. 
Published: May 2016

SUMMARYThis study investigated the incidence and risk to staff groups for sustaining needlestick injuries (NSIs) in the National University Hospital (NUH), Singapore. A retrospective cohort review of incident NSI cases was undertaken to determine the injury rate, causation, and epidemiological profile of such injuries. Analysis of the risk of sustaining recurrent NSI by occupation and location was done using the Cox proportional hazards model. There were 244 NSI cases in 5957 employees in NUH in 2014, giving an incidence rate of 4·1/100 healthcare workers (HCWs) per year. The incidence rate was highest for doctors at 21·3, and 2·7 for nurses; 40·6% of injuries occurred in wards, and 32·8% in operating theatres. There were 27 cases of repeated NSI cases. The estimated cost due to NSIs in NUH ranged from US$ 109 800 to US$ 563 152 in 2014. We conclude that creating a workplace environment where top priority is given to prevention of NSIs in HCWs, is essential to address the high incidence of reported NSIs. The data collected will be of value to inform the design of prevention programmes to reduce further the risk of NSIs in HCWs.
Cerebellar, but not Motor or Parietal, High-Density Anodal Transcranial Direct Current Stimulation Facilitates Motor Adaptation
Authors: Doppelmayr Michael , Pixa Nils Henrik , Steinberg Fabian 
Published: May 2016

AbstractObjectives: Although motor adaptation is a highly relevant process for both everyday life as well as rehabilitation many details of this process are still unresolved. To evaluate the contribution of primary motor (M1), parietal and cerebellar areas to motor adaptation processes transcranial direct current stimulation (tDCS) has been applied. We hypothesized that anodal stimulation of the cerebellum and the M1 improves the learning process in mirror drawing, a task involving fine grained and spatially well-organized hand movements. Methods: High definition tDCS (HD-tDCS) allows a focal stimulation to modulate brain processes. In a single-session double-blind study, we compared the effects of different anodal stimulation procedures. The groups received stimulation either at the cerebellum (CER), at right parietal (PAR), or at left M1, and a SHAM group was included. Participants (n=83) had to complete several mirror drawing tasks before, during, and after stimulation. They were instructed to re-trace a line in the shape of a pentagonal star as fast and accurate as possible. Tracing time (seconds) and accuracy (deviation in mm) have been evaluated. Results: The results indicated that cerebellar HD-tDCS can facilitate motor adaptation in a single session. The stimulation at M1 showed only a tendency to increase motor adaptation and these effects were visible only during the first part of the stimulation. Stimulating the right parietal area, relevant for visuospatial processing did not lead to increased performance. Conclusions: Our results suggest that motor adaptation relies to a great extent on cerebellar functions and HD-tDCS can speed up this process. (JINS, 2016, 22, 928–936)
Can desalinated seawater contribute to iodine-deficiency disorders? An observation and hypothesis
Authors: Ovadia Yaniv S , Gefel Dov , Aharoni Dorit , Turkot Svetlana , Fytlovich Shlomo , Troen Aron M 
Published: May 2016

AbstractObjectiveOver 300 million people rely on desalinated seawater and the numbers are growing. Desalination removes iodine from water and could increase the risk of iodine-deficiency disorders (IDD). The present study assessed the relationship between iodine intake and thyroid function in an area reliant on desalination.DesignA case–control study was performed between March 2012 and March 2014. Thyroid function was rigorously assessed by clinical examination, ultrasound and blood tests, including serum thyroglobulin (Tg) and autoimmune antibodies. Iodine intake and the contribution made by unfiltered tap water were estimated by FFQ. The contribution of drinking-water to iodine intake was modelled using three iodine concentrations: likely, worst-case and best-case scenario.SettingThe setting for the study was a hospital located on the southern Israeli Mediterranean coast.SubjectsAdult volunteers (n102), 21–80 years old, prospectively recruited.ResultsAfter screening, seventy-four participants met the inclusion criteria. Thirty-seven were euthyroid controls. Among those with thyroid dysfunction, twenty-nine were classified with non-autoimmune thyroid disease (NATD) after excluding eight cases with autoimmunity. Seventy per cent of all participants had iodine intake below the Estimated Average Requirement (EAR) of 95 µg/d. Participants with NATD were significantly more likely to have probable IDD with intake below the EAR (OR=5·2; 95 % CI 1·8, 15·2) and abnormal serum Tg>40 ng/ml (OR=5·8; 95 % CI 1·6, 20·8).ConclusionsEvidence of prevalent probable IDD in a population reliant on desalinated seawater supports the urgent need to probe the impact of desalinated water on thyroid health in Israel and elsewhere.
Dark-Field Scanning Transmission Ion Microscopy via Detection of Forward-Scattered Helium Ions with a Microchannel Plate
Authors: Woehl Taylor J. , White Ryan M. , Keller Robert R. 
Published: May 2016

AbstractA microchannel plate was used as an ion sensitive detector in a commercial helium ion microscope (HIM) for dark-field transmission imaging of nanomaterials, i.e. scanning transmission ion microscopy (STIM). In contrast to previous transmission HIM approaches that used secondary electron conversion holders, our new approach detects forward-scattered helium ions on a dedicated annular shaped ion sensitive detector. Minimum collection angles between 125 mrad and 325 mrad were obtained by varying the distance of the sample from the microchannel plate detector during imaging. Monte Carlo simulations were used to predict detector angular ranges at which dark-field images with atomic number contrast could be obtained. We demonstrate atomic number contrast imagingviascanning transmission ion imaging of silica-coated gold nanoparticles and magnetite nanoparticles. Although the resolution of STIM is known to be degraded by beam broadening in the substrate, we imaged magnetite nanoparticles with high contrast on a relatively thick silicon nitride substrate. We expect this new approach to annular dark-field STIM will open avenues for more quantitative ion imaging techniques and advance fundamental understanding of underlying ion scattering mechanisms leading to image formation.
The future of Indian Health Services for native Americans in the United States: an analysis of policy options and recommendations
Authors: Henley Tiffany , Boshier Maureen 
Published: May 2016

AbstractThe passage of the Affordable Care Act in the United States has opened a policy window for the establishment of an independent Medicaid agency for the Navajo Nation. This article explores several policy options to improve health care services for Native Americans. Although there is a lack of scholarly research on the impact of healthcare reform and the effectiveness of current health care programs for American Indians, policymakers should utilize evidence-based research to inform policy decisions.
Phytochrome and retrograde signalling pathways converge to antagonistically regulate a light-induced transcriptional network
Authors: Martín Guiomar , Leivar Pablo , Ludevid Dolores , Tepperman James M. , Quail Peter H. , Monte Elena 
Published: May 2016

AbstractPlastid-to-nucleus retrograde signals emitted by dysfunctional chloroplasts impact photomorphogenic development, but the molecular link between retrograde- and photosensory-receptor signalling has remained unclear. Here, we show that the phytochrome and retrograde signalling (RS) pathways converge antagonistically to regulate the expression of the nuclear-encoded transcription factor GLK1, a key regulator of a light-induced transcriptional network central to photomorphogenesis.GLK1gene transcription is directly repressed by PHYTOCHROME-INTERACTING FACTOR (PIF)-class bHLH transcription factors in darkness, but light-activated phytochrome reverses this activity, thereby inducing expression. Conversely, we show that retrograde signals repress this induction by a mechanism independent of PIF mediation. Collectively, our data indicate that light at moderate levels acts through the plant’s nuclear-localized sensory-photoreceptor system to induce appropriate photomorphogenic development, but at excessive levels, sensed through the separate plastid-localized RS system, acts to suppress such development, thus providing a mechanism for protection against photo-oxidative damage by minimizing the tissue exposure to deleterious radiation.
MNase titration reveals differences between nucleosome occupancy and chromatin accessibility
Authors: Mieczkowski Jakub , Cook April , Bowman Sarah K. , Mueller Britta , Alver Burak H. , Kundu Sharmistha , Deaton Aimee M. , Urban Jennifer A. , Larschan Erica , Park Peter J. , Kingston Robert E. , Tolstorukov Michael Y. 
Published: May 2016

AbstractChromatin accessibility plays a fundamental role in gene regulation. Nucleosome placement, usually measured by quantifying protection of DNA from enzymatic digestion, can regulate accessibility. We introduce a metric that uses micrococcal nuclease (MNase) digestion in a novel manner to measure chromatin accessibility by combining information from several digests of increasing depths. This metric, MACC (MNase accessibility), quantifies the inherent heterogeneity of nucleosome accessibility in which some nucleosomes are seen preferentially at high MNase and some at low MNase. MACC interrogates each genomic locus, measuring both nucleosome location and accessibility in the same assay. MACC can be performed either with or without a histone immunoprecipitation step, and thereby compares histone and non-histone protection. We find that changes in accessibility at enhancers, promoters and other regulatory regions do not correlate with changes in nucleosome occupancy. Moreover, high nucleosome occupancy does not necessarily preclude high accessibility, which reveals novel principles of chromatin regulation.
14-3-3 proteins regulate Tctp–Rheb interaction for organ growth in Drosophila
Authors: Le Thao Phuong , Vuong Linh Thuong , Kim Ah-Ram , Hsu Ya-Chieh , Choi Kwang-Wook 
Published: May 2016

Abstract14-3-3 family proteins regulate multiple signalling pathways. Understanding biological functions of 14-3-3 proteins has been limited by the functional redundancy of conserved isotypes. Here we provide evidence that 14-3-3 proteins regulate two interacting components of Tor signalling in Drosophila, translationally controlled tumour protein (Tctp) and Rheb GTPase. Single knockdown of 14-3-3ɛ or 14-3-3ζ isoform does not show obvious defects in organ development but causes synergistic genetic interaction with Tctp and Rheb to impair tissue growth. 14-3-3 proteins physically interact with Tctp and Rheb. Knockdown of both 14-3-3 isoforms abolishes the binding between Tctp and Rheb, disrupting organ development. Depletion of 14-3-3s also reduces the level of phosphorylated S6 kinase, phosphorylated Thor/4E-BP and cyclin E (CycE). Growth defects from knockdown of 14-3-3 and Tctp are suppressed by CycE overexpression. This study suggests a novel mechanism of Tor regulation mediated by 14-3-3 interaction with Tctp and Rheb.
The TatD-like DNase of Plasmodium is a virulence factor and a potential malaria vaccine candidate
Authors: Chang Zhiguang , Jiang Ning , Zhang Yuanyuan , Lu Huijun , Yin Jigang , Wahlgren Mats , Cheng Xunjia , Cao Yaming , Chen Qijun 
Published: May 2016

AbstractNeutrophil extracellular traps (NETs), composed primarily of DNA and proteases, are released from activated neutrophils and contribute to the innate immune response by capturing pathogens. Plasmodium falciparum, the causative agent of severe malaria, thrives in its host by counteracting immune elimination. Here, we report the discovery of a novel virulence factor of P. falciparum, a TatD-like DNase (PfTatD) that is expressed primarily in the asexual blood stage and is likely utilized by the parasite to counteract NETs. PfTatD exhibits typical deoxyribonuclease activity, and its expression is higher in virulent parasites than in avirulent parasites. A P. berghei TatD-knockout parasite displays reduced pathogenicity in mice. Mice immunized with recombinant TatD exhibit increased immunity against lethal challenge. Our results suggest that the TatD-like DNase is an essential factor for the survival of malarial parasites in the host and is a potential malaria vaccine candidate.
Engineering a Brain Cancer Chip for High-throughput Drug Screening
Authors: Fan Yantao , Nguyen Duong Thanh , Akay Yasemin , Xu Feng , Akay Metin 
Published: May 2016

AbstractGlioblastoma multiforme (GBM) is the most common and malignant of all human primary brain cancers, in which drug treatment is still one of the most effective treatments. However, existing drug discovery and development methods rely on the use of conventional two-dimensional (2D) cell cultures, which have been proven to be poor representatives of native physiology. Here, we developed a novel three-dimensional (3D) brain cancer chip composed of photo-polymerizable poly(ethylene) glycol diacrylate (PEGDA) hydrogel for drug screening. This chip can be produced after a few seconds of photolithography and requires no silicon wafer, replica molding, and plasma bonding like microfluidic devices made of poly(dimethylsiloxane) (PDMS). We then cultured glioblastoma cells (U87), which formed 3D brain cancer tissues on the chip, and used the GBM chip to perform combinatorial treatment of Pitavastatin and Irinotecan. The results indicate that this chip is capable of high-throughput GBM cancer spheroids formation, multiple-simultaneous drug administration, and a massive parallel testing of drug response. Our approach is easily reproducible, and this chip has the potential to be a powerful platform in cases such as high-throughput drug screening and prolonged drug release. The chip is also commercially promising for other clinical applications, including 3D cell culture and micro-scale tissue engineering.
Radiomic Texture Analysis Mapping Predicts Areas of True Functional MRI Activity
Authors: Hassan Islam , Kotrotsou Aikaterini , Bakhtiari Ali Shojaee , Thomas Ginu A. , Weinberg Jeffrey S. , Kumar Ashok J. , Sawaya Raymond , Luedi Markus M. , Zinn Pascal O. , Colen Rivka R. 
Published: May 2016

AbstractIndividual analysis of functional Magnetic Resonance Imaging (fMRI) scans requires user-adjustment of the statistical threshold in order to maximize true functional activity and eliminate false positives. In this study, we propose a novel technique that uses radiomic texture analysis (TA) features associated with heterogeneity to predict areas of true functional activity. Scans of 15 right-handed healthy volunteers were analyzed using SPM8. The resulting functional maps were thresholded to optimize visualization of language areas, resulting in 116 regions of interests (ROIs). A board-certified neuroradiologist classified different ROIs into Expected (E) and Non-Expected (NE) based on their anatomical locations. TA was performed using the mean Echo-Planner Imaging (EPI) volume, and 20 rotation-invariant texture features were obtained for each ROI. Using forward stepwise logistic regression, we built a predictive model that discriminated between E and NE areas of functional activity, with a cross-validation AUC and success rate of 79.84% and 80.19% respectively (specificity/sensitivity of 78.34%/82.61%). This study found that radiomic TA of fMRI scans may allow for determination of areas of true functional activity, and thus eliminate clinician bias.
A thaumatin-like protein of Ocimum basilicum confers tolerance to fungal pathogen and abiotic stress in transgenic Arabidopsis
Authors: Misra Rajesh Chandra , Sandeep  , Kamthan Mohan , Kumar Santosh , Ghosh Sumit 
Published: May 2016

AbstractPlant often responds to fungal pathogens by expressing a group of proteins known as pathogenesis-related proteins (PRs). The expression of PR is mediated through pathogen-induced signal-transduction pathways that are fine-tuned by phytohormones such as methyl jasmonate (MeJA). Here, we report functional characterization of an Ocimum basilicum PR5 family member (ObTLP1) that was identified from a MeJA-responsive expression sequence tag collection. ObTLP1 encodes a 226 amino acid polypeptide that showed sequence and structural similarities with a sweet-tasting protein thaumatin of Thaumatococcus danielli and also with a stress-responsive protein osmotin of Nicotiana tabacum. The expression of ObTLP1 in O. basilicum was found to be organ-preferential under unstressed condition and responsive to biotic and abiotic stresses and multiple phytohormone elicitations. Bacterially-expressed recombinant ObTLP1 inhibited mycelial growth of the phytopathogenic fungi, Scleretonia sclerotiorum and Botrytis cinerea; thereby, suggesting its antifungal activity. Ectopic expression of ObTLP1 in Arabidopsis led to enhanced tolerance to S. sclerotiorum and B. cinerea infections and also to dehydration and salt stress. Moreover, induced expression of the defense marker genes suggested up-regulation of the defense-response pathways in ObTLP1-expressing Arabidopsis upon fungal challenge. Thus, ObTLP1 might be useful for providing tolerance to the fungal pathogens and abiotic stresses in crops.
Rigid proteins and softening of biological membranes—with application to HIV-induced cell membrane softening
Authors: Agrawal Himani , Zelisko Matthew , Liu Liping , Sharma Pradeep 
Published: May 2016

AbstractA key step in the HIV-infection process is the fusion of the virion membrane with the target cell membrane and the concomitant transfer of the viral RNA. Experimental evidence suggests that the fusion is preceded by considerable elastic softening of the cell membranes due to the insertion of fusion peptide in the membrane. What are the mechanisms underpinning the elastic softening of the membrane upon peptide insertion? A broader question may be posed: insertion of rigid proteins in soft membranes ought to stiffen the membranes not soften them. However, experimental observations perplexingly appear to show that rigid proteins may either soften or harden membranes even though conventional wisdom only suggests stiffening. In this work, we argue that regarding proteins as merely non-specific rigid inclusions is flawed and each protein has a unique mechanical signature dictated by its specific interfacial coupling to the surrounding membrane. Predicated on this hypothesis, we have carried out atomistic simulations to investigate peptide-membrane interactions. Together with a continuum model, we reconcile contrasting experimental data in the literature including the case of HIV-fusion peptide induced softening. We conclude that the structural rearrangements of the lipids around the inclusions cause the softening or stiffening of the biological membranes.
Mechanism of Ribonuclease III Catalytic Regulation by Serine Phosphorylation
Authors: Gone Swapna , Alfonso-Prieto Mercedes , Paudyal Samridhdi , Nicholson Allen W. 
Published: May 2016

AbstractRibonuclease III (RNase III) is a conserved, gene-regulatory bacterial endonuclease that cleaves double-helical structures in diverse coding and noncoding RNAs. RNase III is subject to multiple levels of control, reflective of its global regulatory functions. Escherichia coli (Ec) RNase III catalytic activity is known to increase during bacteriophage T7 infection, reflecting the expression of the phage-encoded protein kinase, T7PK. However, the mechanism of catalytic enhancement is unknown. This study shows that Ec-RNase III is phosphorylated on serine in vitro by purified T7PK, and identifies the targets as Ser33 and Ser34 in the N-terminal catalytic domain. Kinetic experiments reveal a 5-fold increase in kcat and a 1.4-fold decrease in Km following phosphorylation, providing a 7.4–fold increase in catalytic efficiency. Phosphorylation does not change the rate of substrate cleavage under single-turnover conditions, indicating that phosphorylation enhances product release, which also is the rate-limiting step in the steady-state. Molecular dynamics simulations provide a mechanism for facilitated product release, in which the Ser33 phosphomonoester forms a salt bridge with the Arg95 guanidinium group, thereby weakening RNase III engagement of product. The simulations also show why glutamic acid substitution at either serine does not confer enhancement, thus underscoring the specific requirement for a phosphomonoester.
The mechanism of deceleration of nucleation and crystal growth by the small addition of transition metals to lithium disilicate glasses
Authors: Thieme Katrin , Avramov Isak , Rüssel Christian 
Published: May 2016

AbstractThe addition of small amounts of niobium or tantalum oxide to lithium disilicate glass provokes a drastic decrease of the steady-state nucleation rates and the crystal growth velocities. The viscosity of the residual glassy matrix is considered as a function of the crystallization degree in the course of a non-isothermal crystallization. For simplification, a homogeneous distribution of the added oxides in the glass matrix is assumed. While the viscosity initially decreases, it significantly increases again for higher crystallization degrees hindering crystal growth. However, it was shown that the additives are enriched at the crystal interface. Several possible reasons for the inhibition of nucleation and growth kinetics such as viscosity, interfacial energy crystal/glassy phase, thermodynamic driving force or impingement rate are discussed. Since the crystallization front is blocked by the additives the impingement rate is decreased with increasing additive concentration. Since small concentrations of Nb2O5 and Ta2O5 have a drastic effect on the nucleation, these components should be enriched at the interface crystal/glass. This will only take place, if it leads to a decrease in the interfacial energy. Since this effect alone should result in an increase of the nucleation rate, it must be overcompensated by kinetic effects.
Tunable one-dimensional electron gas carrier densities at nanostructured oxide interfaces
Authors: Zhuang Houlong L. , Zhang Lipeng , Xu Haixuan , Kent P. R. C. , Ganesh P. , Cooper Valentino R. 
Published: May 2016

AbstractThe emergence of two-dimensional metallic states at the LaAlO3/SrTiO3 (LAO/STO) heterostructure interface is known to occur at a critical thickness of four LAO layers. This insulator to-metal transition can be explained through the “polar catastrophe” mechanism arising from the divergence of the electrostatic potential at the LAO surface. Here, we demonstrate that nanostructuring can be effective in reducing or eliminating this critical thickness. Employing a modified “polar catastrophe” model, we demonstrate that the nanowire heterostructure electrostatic potential diverges more rapidly as a function of layer thickness than in a regular heterostructure. Our first-principles calculations indicate that for nanowire heterostructures a robust one-dimensional electron gas (1DEG) can be induced, consistent with recent experimental observations of 1D conductivity at LAO/STO steps. Similar to LAO/STO 2DEGs, we predict that the 1D charge density decays laterally within a few unit cells away from the nanowire; thus providing a mechanism for tuning the carrier dimensionality between 1D and 2D conductivity. Our work provides insight into the creation and manipulation of charge density at an oxide heterostructure interface and therefore may be beneficial for future nanoelectronic devices and for the engineering of novel quantum phases.