217 research outputs found

    Quaternionic Salkowski Curves and Quaternionic Similar Curves

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    In this paper, we give the definitions and characterizations of quaternionic Salkowski, quaternionic anti-Salkowski and quaternionic similar curves in the Euclidean spaces E^3 and E^4. We obtain relationships between these curves and some special quaternionic curves such as quaternionic slant helices and quaternionic B2-slant helices.Comment: 17 page

    High-temperature ferromagnetism in Co-implanted TiO2 rutile

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    We report on structural, magnetic and electronic properties of Co-implanted TiO2(1 0 0) rutile single crystals for different implantation doses. Strong ferromagnetism at room temperature and above is observed in TiO 2 rutile plates after cobalt ion implantation, with magnetic parameters depending on the cobalt implantation dose. While the structural data indicate the presence of metallic cobalt clusters, the multiplet structure of the Co L3 edge in the XAS spectra provides evidence that a sizeable portion of the dopants occupy substitutional Co2+ sites. The detailed analysis of the structural and magnetic properties indicates that there are two magnetic phases in Co-implanted TiO2 plates. One is a ferromagnetic phase due to the formation of long range ferromagnetic ordering between implanted magnetic cobalt ions in the rutile phase, and the second one is a superparamagnetic phase which originates from the formation of metallic cobalt clusters in the implanted region. Using x-ray resonant magnetic scattering, the element specific magnetizations of cobalt, oxygen and titanium in Co-implanted TiO2 single crystals are investigated. Magnetic dichroism was observed at the Co L2,3 edges as well as at the O K edge. Anomalous Hall effect measurement indicates n-type carriers in Co-implanted TiO 2 rutile. The interaction mechanism, which leads to ferromagnetic ordering of substituted cobalt ions in the host matrix, is also discussed. © 2009 IOP Publishing Ltd

    Small-molecule inhibition of STOML3 oligomerization reverses pathological mechanical hypersensitivity

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    The skin is equipped with specialized mechanoreceptors that allow the perception of the slightest brush. Indeed, some mechanoreceptors can detect even nanometer-scale movements. Movement is transformed into electrical signals via the gating of mechanically activated ion channels at sensory endings in the skin. The sensitivity of Piezo mechanically gated ion channels is controlled by stomatin-like protein-3 (STOML3), which is required for normal mechanoreceptor function. Here we identify small-molecule inhibitors of STOML3 oligomerization that reversibly reduce the sensitivity of mechanically gated currents in sensory neurons and silence mechanoreceptors in vivo\textit{in vivo}. STOML3 inhibitors in the skin also reversibly attenuate fine touch perception in normal mice. Under pathophysiological conditions following nerve injury or diabetic neuropathy, the slightest touch can produce pain, and here STOML3 inhibitors can reverse mechanical hypersensitivity. Thus, small molecules applied locally to the skin can be used to modulate touch and may represent peripherally available drugs to treat tactile-driven pain following neuropathy.This study was funded by DFG collaborative research grant SFB958 (projects A09 to K.P. and G.R.L., A01 to V.H. and Z02 to J.S.). Additional support was provided by a senior ERC grant (grant number 294678 to G.R.L.) and by the NeuroCure Cluster of Excellence (to V.H., G.R.L. and J.F.A.P.). K.P. was supported by a Cecile-Vogt Fellowship (MDC). S.P. was supported by a Marie Curie Fellowship from the European Union (grant number 253663 Touch in situ). C.P. received a Ph.D. fellowship from the University of Cagliari. J.F.A.P. was funded by a European Research Council (ERC) starting grant (ERC-2010-StG-260590), the DFG (FOR 1341, FOR 2143), the Berlin Institute of Health (BIH) and the European Union (FP7, 3x3Dimaging 323945). R.K. was supported by an ERC Advanced Investigator grant (294293-PAIN PLASTICITY). D.H. was funded by the Berlin Institute of Health (BIH). E.St.J.S., L.E. and M.M. were supported by an Alexander von Humboldt Fellowship

    Modeling healthcare authorization and claim submissions using the openEHR dual-model approach

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    <p>Abstract</p> <p>Background</p> <p>The TISS standard is a set of mandatory forms and electronic messages for healthcare authorization and claim submissions among healthcare plans and providers in Brazil. It is not based on formal models as the new generation of health informatics standards suggests. The objective of this paper is to model the TISS in terms of the openEHR archetype-based approach and integrate it into a patient-centered EHR architecture.</p> <p>Methods</p> <p>Three approaches were adopted to model TISS. In the first approach, a set of archetypes was designed using ENTRY subclasses. In the second one, a set of archetypes was designed using exclusively ADMIN_ENTRY and CLUSTERs as their root classes. In the third approach, the openEHR ADMIN_ENTRY is extended with classes designed for authorization and claim submissions, and an ISM_TRANSITION attribute is added to the COMPOSITION class. Another set of archetypes was designed based on this model. For all three approaches, templates were designed to represent the TISS forms.</p> <p>Results</p> <p>The archetypes based on the openEHR RM (Reference Model) can represent all TISS data structures. The extended model adds subclasses and an attribute to the COMPOSITION class to represent information on authorization and claim submissions. The archetypes based on all three approaches have similar structures, although rooted in different classes. The extended openEHR RM model is more semantically aligned with the concepts involved in a claim submission, but may disrupt interoperability with other systems and the current tools must be adapted to deal with it.</p> <p>Conclusions</p> <p>Modeling the TISS standard by means of the openEHR approach makes it aligned with ISO recommendations and provides a solid foundation on which the TISS can evolve. Although there are few administrative archetypes available, the openEHR RM is expressive enough to represent the TISS standard. This paper focuses on the TISS but its results may be extended to other billing processes. A complete communication architecture to simulate the exchange of TISS data between systems according to the openEHR approach still needs to be designed and implemented.</p

    Neurogenic bladder in patients with traumatic spinal cord injury: Treatment and follow-up

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    Study design:Multi-center, cross-sectional study.Objectives:Our aim was to evaluate the treatment methods and follow-up of neurogenic bladder in patients with traumatic spinal cord injury retrospectively using a questionnaire.Setting: Turkey.Methods:Three hundred and thirty-seven patients who had spinal cord injury for at least 2 years were enrolled from six centers in the neurogenic bladder study group. They were asked to fill-out a questionnaire about treatments they received and techniques they used for bladder management.Results:The study included 246 male and 91 female patients with a mean age of 42±14 years. Intermittent catheterization ( IC) was performed in 77.9% of the patients, 3.8% had indwelling catheters, 13.8% had normal spontaneous micturition, 2.6% performed voiding maneuvers, 1.3% used diapers and 0.6% used condom catheters. No gender difference was found regarding the techniques used in bladder rehabilitation ( P>0.05). Overall, 63.2% of patients used anticholinergic drugs; anticholinergic drug use was similar between genders ( P>0.05). The most common anticholinergic drug used was oxybutynin ( 40.3%), followed by trospium ( 32.6%), tolterodine ( 19.3%) darifenacin ( 3.3%), propiverine ( 3.3%) and solifenacin ( 1.1%). The specialties of the physicians who first prescribed the anticholinergic drug were physiatrists ( 76.2%), urologists ( 22.1%) and neurologists ( 1.7%). Only four patients had previously received injections of botulinum-toxin-A into the detrusor muscle and three of them stated that their symptoms showed improvement. Most of the patients ( 77%) had regular follow-up examinations, including urine cultures, urinary system ultrasound and urodynamic tests, when necessary; the reasons for not having regular control visits were living distant from hospital ( 15.3%) and monetary problems ( 7.7%). Of the patients, 42.7% did not experience urinary tract infections ( UTI), 36.4% had bacteriuria but no UTI episodes with fever, 15.9% had 1-2 clinical UTI episodes per year and 5% had ≥3 clinical UTIs. The clinical characteristics of patients with and without UTI ( at least one symptomatic UTI during 1 year) were similar ( P>0.05). The frequency of symptomatic UTI was similar in patients using different bladder management techniques ( P>0.05).Conclusion:The most frequently used technique for bladder rehabilitation in patients with SCI was IC ( 77.9%). In all, 63.2% of patients used anticholinergic drugs, oxybutynin being the most commonly used drug. Also, 77% of patients had regular control visits for neurogenic bladder; 42.7% did not experience any UTIs. © 2014 International Spinal Cord Society

    Intermittent catheterization in patients with traumatic spinal cord injury: Obstacles, worries, level of satisfaction

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    Objectives: The aim of this study is to examine the obstacles in people with traumatic spinal cord injury (SCI) face performing intermittent catheterization (IC), also their worries and level of satisfaction. Methods: Two hundred sixty-nine patients performing IC for at least 3 months were asked to fill-out a questionnaire about their opinions on IC. Results: In total, 69.5% of patients performed IC themselves, 10.4% had performed by their mothers, 7.8% by another caregiver and 7.4% by their spouse. For the 72 (26%) patients unable to apply IC, reasons were insufficient hand function (56.1%), being unable to sit appropriately (35.4%) and spasticity (8.5%). In all, 70% of male patients had insufficient hand function, 20% could not sit and 10% had spasticity while 56.3% of female patients could not sit, 37.5% had insufficient hand function and 63% had spasticity. Difference between sexes was found to be statistically significant (P<0.05). Worries patients had when starting IC were fear of being dependent on IC (50.2%), accidentally injuring self (43.8%), embarrassment (43.2%), causing an infection (40.2%), bleeding (32.7%), fear of feeling pain (30.2%) and hygiene (24.7%). More women felt embarrassment; other items were similar in both sexes. In all, 46.9% of patients had urinary incontinence in intervals. Conclusion: In total, 69.5% of patients performed IC themselves. Men's most common obstacle was insufficient hand function while women's was being unable to sit appropriately. Patients' most common worries were being dependent on IC for life. In all, 46.9% had incontinence in intervals; 47.9% said IC improved their life quality; and 97.4% preferred IC over continuous catheterization. © 2014 International Spinal Cord Society All rights reserved

    A comparative study on the effects of a pesticide (cypermethrin) and two metals (copper, lead) to serum biochemistry of Nile tilapia, Oreochromis niloticus

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    The present study was designed to compare the responses in freshwater fish Oreochromis niloticus exposed to a synthetic pyrethroid, cypermethrin (CYP); an essential metal, copper (Cu); and a nonessential metal, lead (Pb). Fish were exposed to 0.05 μg/l CYP, 0.05 mg/l Cu, and 0.05 mg/l Pb for 4 and 21 days, and the alterations in serum enzyme activities, metabolite, and ion levels were determined. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities increased in response to CYP, Cu, and Pb exposures at both exposure periods. While elevations in alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) activities and in cholesterol level were observed in pesticide-exposed fish at 4 and 21 days, they increased in Cu- and Pb-exposed fish at 21 days. Although metal-exposed fish showed increases in cortisol and glucose levels at 4 days followed by a return to control levels at the end of the exposure period, their levels elevated in pesticide-exposed fish at both exposure periods. Total protein levels decreased in Pb- and pesticide-exposed fish at 21 days. Na+ and Cl− levels decreased in pesticide-exposed fish at both exposure periods and in Cu- and Pb-exposed fish at 21 days. The exposures of pesticide and metals caused an elevation in K+ level at the end of the exposure period. The present study showed that observed alterations in all serum biochemical parameters of fish-treated pesticide were higher than those in fish exposed to metals
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