256 research outputs found

    Chemical vapour deposition grown carbon nanotubes for interconnect technology

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    Multiwall carbon nanotubes have been grown by catalytic chemical vapour deposition using iron catalyst particles drop cast onto etched silicon wafers. The catalyst used was poly(styrene-vinylferrocene) in toluene solution which has an iron content of 2.1%. The etched silicon wafers have trench regions of varying widths ranging from 0.32 to 1 μm. For trench widths below 0.5 μm the number of “interconnecting” tubes growing from one side of the trench to the other increases sharply. A significant proportion of these “interconnects” are found to be Y-junction and multiple junction MWNTs. A systematic study of the effects of each of the growth conditions (temperature, run time, gas flow, catalyst concentration and trench width) versus interconnect yield was carried out. Densities of ~ 1.6 interconnects per micron of trench are obtained, with junction structures accounting for 38% of these interconnects. Densities can be controlled through modification of chemical vapour deposition conditions

    Internal and external cooling methods and their effect on body temperature, thermal perception and dexterity

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    © 2018 The Authors. Published by PLOS. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1371/journal.pone.0191416© 2018 Maley et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Objective The present study aimed to compare a range of cooling methods possibly utilised by occupational workers, focusing on their effect on body temperature, perception and manual dexterity. Methods Ten male participants completed eight trials involving 30 min of seated rest followed by 30 min of cooling or control of no cooling (CON) (34C, 58% relative humidity). The cooling methods utilised were: ice cooling vest (CV0), phase change cooling vest melting at 14C (CV14), evaporative cooling vest (CVEV), arm immersion in 10C water (AI), portable water-perfused suit (WPS), heliox inhalation (HE) and ice slushy ingestion (SL). Immediately before and after cooling, participants were assessed for fine (Purdue pegboard task) and gross (grip and pinch strength) manual dexterity. Rectal and skin temperature, as well as thermal sensation and comfort, were monitored throughout. Results Compared with CON, SL was the only method to reduce rectal temperature (P = 0.012). All externally applied cooling methods reduced skin temperature (P0.05). Conclusion The present study observed that ice ingestion or ice applied to the skin produced the greatest effect on rectal and skin temperature, respectively. AI should not be utilised if workers require subsequent fine manual dexterity. These results will help inform future studies investigating appropriate pre-cooling methods for the occupational worker.This project is financially supported by the US Government through the Technical Support Working Group within the Combating Terrorism Technical Support Office.Published versio

    South Dakota Pregnancy Survey 2016 Data Report

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    The South Dakota Department of Health, in conjunction with the EA Martin Program at South Dakota State University, conducted a 2016 Pregnancy Risk Assessment Monitoring System (PRAMS)-like surveillance project. The 2016 South Dakota PRAMS-like survey was a statewide population-based survey based on a stratified random sample of women who gave birth to a live-born infant, thereby allowing rates to be estimated for South Dakota mothers giving birth in 2016. The topics included in this survey were selected to enhance our understanding of maternal attitudes and behaviors around the time of pregnancy and the weighted response rate was 67.6%

    Rural vs. Non-rural Differences and Longitudinal Bone Changes by DXA and pQCT in Men Aged 20-66 Years: A Population-Based Study

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    The purpose of this research was to determine whether there were differences in estimated means and rates of change in BMC, bone area, BMD and measures of bone geometry among men (n=544) from three distinct populations (Hutterite [rural], rural non-Hutterite, non-rural), and whether activity levels or calcium intake explain these population differences. Men were enrolled in the South Dakota Rural Bone Health Study and followed for 7.5 years to estimate means and rates of change in bone mass, density, size and geometry. Femoral neck (FN) and spine measurements were obtained every 18 months by DXA and distal radius (4% and 20%) measurements by pQCT. Activity measurements and calcium intake were obtained quarterly for the first 3 years and at 54, 72, and 90 months. Rural men had greater percent time in moderate plus vigorous activity (mean ± SD: 22 ± 10 vs. 15 ± 8%,

    Distinct Nav1.7-dependent pain sensations require different sets of sensory and sympathetic neurons

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    Human acute and inflammatory pain requires the expression of voltage-gated sodium channel Nav1.7 but its significance for neuropathic pain is unknown. Here we show that Nav1.7 expression in different sets of mouse sensory and sympathetic neurons underlies distinct types of pain sensation. Ablating Nav1.7 gene (SCN9A) expression in all sensory neurons using Advillin-Cre abolishes mechanical pain, inflammatory pain and reflex withdrawal responses to heat. In contrast, heat-evoked pain is retained when SCN9A is deleted only in Nav1.8-positive nociceptors. Surprisingly, responses to the hotplate test, as well as neuropathic pain, are unaffected when SCN9A is deleted in all sensory neurons. However, deleting SCN9A in both sensory and sympathetic neurons abolishes these pain sensations and recapitulates the pain-free phenotype seen in humans with SCN9A loss-of-function mutations. These observations demonstrate an important role for Nav1.7 in sympathetic neurons in neuropathic pain, and provide possible insights into the mechanisms that underlie gain-of-function Nav1.7-dependent pain conditions

    Core temperature responses to cold-water immersion recovery: A pooled-data analysis

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    © 2018 Human Kinetics, Inc. Purpose: To examine the effect of postexercise cold-water immersion (CWI) protocols, compared with control (CON), on the magnitude and time course of core temperature (Tc) responses. Methods: Pooled-data analyses were used to examine the Tc responses of 157 subjects from previous postexercise CWI trials in the authors’ laboratories. CWI protocols varied with different combinations of temperature, duration, immersion depth, and mode (continuous vs intermittent). Tc was examined as a double difference (ΔΔTc), calculated as the change in Tc in CWI condition minus the corresponding change in CON. The effect of CWI on ΔΔTc was assessed using separate linear mixed models across 2 time components (component 1, immersion; component 2, postintervention). Results: Intermittent CWI resulted in a mean decrease in ΔΔTc that was 0.25°C (0.10°C) (estimate [SE]) greater than continuous CWI during the immersion component (P = .02). There was a significant effect of CWI temperature during the immersion component (P = .05), where reductions in water temperature of 1°C resulted in decreases in ΔΔTc of 0.03°C (0.01°C). Similarly, the effect of CWI duration was significant during the immersion component (P = .01), where every 1 min of immersion resulted in a decrease in ΔΔTc of 0.02°C (0.01°C). The peak difference in Tc between the CWI and CON interventions during the postimmersion component occurred at 60 min postintervention. Conclusions: Variations in CWI mode, duration, and temperature may have a significant effect on the extent of change in Tc. Careful consideration should be given to determine the optimal amount of core cooling before deciding which combination of protocol factors to prescribe

    The lidocaine metabolite N-ethylglycine has antinociceptive effects in experimental inflammatory and neuropathic pain

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    Glycine transporter 1 (GlyT1) plays a crucial role in regulating extracellular glycine concentrations and might thereby constitute a new drug target for the modulation of glycinergic inhibition in pain signaling. Consistently with this view, inhibition of GlyT1 has been found to induce antinociceptive effects in various animal pain models. We have shown previously that the lidocaine metabolite N-ethylglycine (EG) reduces GlyT1-dependent glycine uptake by functioning as an artificial substrate for this transporter. Here we show that EG is specific for GlyT1 and that in rodent models of inflammatory and neuropathic pain, systemic treatment with EG results in an efficient amelioration of hyperalgesia and allodynia without affecting acute pain. There was no effect on motor coordination or the development of inflammatory edema. No adverse neurologic effects were observed following repeated high-dose application of EG. EG concentrations both, in blood and spinal fluid, correlated with an increase of glycine concentration in spinal fluid. The time courses of the EG and glycine concentrations corresponded well with the antinociceptive effect. Additionally, we found that EG reduced the increase in neuronal firing of wide-dynamic-range neurons caused by inflammatory pain induction. These findings suggest that systemically applied lidocaine exerts antihyperalgesic effects via its metabolite EG in vivo, by enhancing spinal inhibition of pain processing through GlyT1 modulation and subsequent increase of glycine concentrations at glycinergic inhibitory synapses. EG and other substrates of GlyT1, therefore, may be a useful therapeutic agent in chronic pain states involving spinal disinhibition

    Consensus and ordering in language dynamics

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    We consider two social consensus models, the AB-model and the Naming Game restricted to two conventions, which describe a population of interacting agents that can be in either of two equivalent states (A or B) or in a third mixed (AB) state. Proposed in the context of language competition and emergence, the AB state was associated with bilingualism and synonymy respectively. We show that the two models are equivalent in the mean field approximation, though the differences at the microscopic level have non-trivial consequences. To point them out, we investigate an extension of these dynamics in which confidence/trust is considered, focusing on the case of an underlying fully connected graph, and we show that the consensus-polarization phase transition taking place in the Naming Game is not observed in the AB model. We then consider the interface motion in regular lattices. Qualitatively, both models show the same behavior: a diffusive interface motion in a one-dimensional lattice, and a curvature driven dynamics with diffusing stripe-like metastable states in a two-dimensional one. However, in comparison to the Naming Game, the AB-model dynamics is shown to slow down the diffusion of such configurations.Comment: 7 pages, 6 figure

    A novel human pain insensitivity disorder caused by a point mutation in ZFHX2

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    Chronic pain is a major global public health issue causing a severe impact on both the quality of life for sufferers and the wider economy. Despite the significant clinical burden, little progress has been made in terms of therapeutic development. A unique approach to identifying new human-validated analgesic drug targets is to study rare families with inherited pain insensitivity. Here we have analysed an otherwise normal family where six affected individuals display a pain insensitive phenotype that is characterized by hyposensitivity to noxious heat and painless bone fractures. This autosomal dominant disorder is found in three generations and is not associated with a peripheral neuropathy. A novel point mutation in ZFHX2, encoding a putative transcription factor expressed in small diameter sensory neurons, was identified by whole exome sequencing that segregates with the pain insensitivity. The mutation is predicted to change an evolutionarily highly conserved arginine residue 1913 to a lysine within a homeodomain. Bacterial artificial chromosome (BAC) transgenic mice bearing the orthologous murine p.R1907K mutation, as well as Zfhx2 null mutant mice, have significant deficits in pain sensitivity. Gene expression analyses in dorsal root ganglia from mutant and wild-Type mice show altered expression of genes implicated in peripheral pain mechanisms. The ZFHX2 variant and downstream regulated genes associated with a human pain-insensitive phenotype are therefore potential novel targets for the development of new analgesic drugs. awx326media1 5680039660001 The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain.We thank the Medical Research Council (J.J.C., Career Development Award, G1100340), Wellcome Trust (200183/ Z/15/Z and 101054/Z/13/Z) and Arthritis Research UK (20200) for generous support and Shionogi for an academic research grant (165302). Thanks to the University of Siena for partially funding this research. J.T.B. is supported by a Research Fellowship from the Alzheimer�s Society. J.D.R. received funding from the Wellcome Trust through the London Pain Consortium and from Colciencias through a Francisco Jose de Caldas Scholarship (LASPAU, Harvard University). D.L.H.B. is a Wellcome senior clinical scientist (ref. no. 095698z/11/z and 202747/Z/16/Z) and member of the Wellcome Pain Consortium.Scopu

    Mouse DRG Cell Line with Properties of Nociceptors

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    In vitro cell lines from DRG neurons aid drug discovery because they can be used for early stage, high-throughput screens for drugs targeting pain pathways, with minimal dependence on animals. We have established a conditionally immortal DRG cell line from the Immortomouse. Using immunocytochemistry, RT-PCR and calcium microfluorimetry, we demonstrate that the cell line MED17.11 expresses markers of cells committed to the sensory neuron lineage. Within a few hours under differentiating conditions, MED17.11 cells extend processes and following seven days of differentiation, express markers of more mature DRG neurons, such as NaV1.7 and Piezo2. However, at least at this time-point, the nociceptive marker NaV1.8 is not expressed, but the cells respond to compounds known to excite nociceptors, including the TRPV1 agonist capsaicin, the purinergic receptor agonist ATP and the voltage gated sodium channel agonist, veratridine. Robust calcium transients are observed in the presence of the inflammatory mediators bradykinin, histamine and norepinephrine. MED17.11 cells have the potential to replace or reduce the use of primary DRG culture in sensory, pain and developmental research by providing a simple model to study acute nociception, neurite outgrowth and the developmental specification of DRG neurons
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