529 research outputs found

    Disability related to chronic low back pain: prevalence abd associated factors

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    Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Disability related to chronic low back pain (CLBP) is a complex and multidimensional phenomenon. The aim of the study was to identify the prevalence of disability and factors associated with disability outcome in 177 CLBP adults. Respondents were recruited from three health care service centers and answered questions from: Demographic Identification Form, Oswestry Disability Index, Chronic Pain Self-efficacy Scale, Tampa Scale Kinesiophobia, Beck Depression Inventory, and the Revised Piper Fatigue Scale. The prevalence of disability among the respondents was 65% (95% CI: 57.5 - 72.0), and disability was moderate to severe in 80.7% of them. The multiple regression model identified three factors as independently associated with disability: work situation, low self-efficacy and depression. The factors identified to be associated with disability are modifiable. Interventions such as work relocation, depression treatment and re-conceptualization of self-efficacy may have an important impact in preventing and reducing disability in chronic low back pain patients.46SI1623Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Solid Electrolytic Substrates for High Performance Transistors and Circuits

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    Ionic liquids/gels have been used to realize field-effect-transistors (FETs) with two dimensional (2D) transition metal dichalcogenides (TMDs) [1]. Although near ideal gating has been reported with this biasing scheme, it suffers from several issues such as, liquid nature of the electrolyte, its humidity dependency and freezing at low temperatures [2]. Recently, air-stable solid electrolytes have been developed, thanks to the advancement in battery technology [3]. Although insulator-to-metal transition has been reported, the realization of 2D TMD FETs on solid electrolytic substrate has not been reported so far to the best of our knowledge [4]. In this work, we demonstrate a lithium ion (Liion) solid electrolytic substrate based TMD transistor and a CMOS amplifier, with near ideal gating efficiency reaching 60 mV/dec subthreshold swing, and amplifier gain ~34, the highest among comparable inverte

    Lithium-ion electrolytic substrates for sub-1V high-performance transition metal dichalcogenide transistors and amplifiers

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    Electrostatic gating of two-dimensional (2D) materials with ionic liquids (ILs), leading to the accumulation of high surface charge carrier densities, has been often exploited in 2D devices. However, the intrinsic liquid nature of ILs, their sensitivity to humidity, and the stress induced in frozen liquids inhibit ILs from constituting an ideal platform for electrostatic gating. Here we report a lithium-ion solid electrolyte substrate, demonstrating its application in high-performance back-gated n-type MoS2 and p-type WSe2 transistors with sub-threshold values approaching the ideal limit of 60 mV/dec and complementary inverter amplifier gain of 34, the highest among comparable amplifiers. Remarkably, these outstanding values were obtained under 1 V power supply. Microscopic studies of the transistor channel using microwave impedance microscopy reveal a homogeneous channel formation, indicative of a smooth interface between the TMD and underlying electrolytic substrate. These results establish lithium-ion substrates as a promising alternative to ILs for advanced thin-film devices

    Evolutionary and pulsation properties of Type II Cepheids

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    We discuss the observed pulsation properties of Type II Cepheids (TIICs) in the Galaxy and Magellanic Clouds. The period (P) distributions, luminosity amplitudes and population ratios of the three different sub-groups (BL Herculis[BLH, P20 days]) are quite similar in different stellar systems, suggesting a common evolutionary channel and a mild dependence on both metallicity and environment. We present a homogeneous theoretical framework based on Horizontal Branch (HB) evolutionary models, envisaging that TIICs are mainly old (t<10 Gyr), low-mass stars. The BLHs are predicted to be post early asymptotic giant branch (PEAGB) stars (double shell burning) on the verge of reaching their AGB track (first crossing of the instability strip), while WVs are a mix of PEAGB and post-AGB stars (hydrogen shell burning) moving from cool to hot (second crossing). Thus suggesting that they are a single group of variable stars. RVTs are predicted to be a mix of post-AGB stars along their second crossing (short-period tail) and thermally pulsing AGB stars (long-period tail) evolving towards their white dwarf cooling sequence. We also present several sets of synthetic HB models by assuming a bimodal mass distribution along the HB. Theory suggests, in agreement with observations, that TIIC pulsation properties marginally depend on metallicity. Predicted period distributions and population ratios for BLHs agree quite well with observations, while those for WVs and RVTs are almost a factor of two smaller and larger than observed, respectively. Moreover, the predicted period distributions for WVs peak at periods shorter than observed, while those for RVTs display a long period tail not supported by observations. We investigate several avenues to explain these differences, but more detailed calculations are required to address them

    A Unifying Model of Genome Evolution Under Parsimony

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    We present a data structure called a history graph that offers a practical basis for the analysis of genome evolution. It conceptually simplifies the study of parsimonious evolutionary histories by representing both substitutions and double cut and join (DCJ) rearrangements in the presence of duplications. The problem of constructing parsimonious history graphs thus subsumes related maximum parsimony problems in the fields of phylogenetic reconstruction and genome rearrangement. We show that tractable functions can be used to define upper and lower bounds on the minimum number of substitutions and DCJ rearrangements needed to explain any history graph. These bounds become tight for a special type of unambiguous history graph called an ancestral variation graph (AVG), which constrains in its combinatorial structure the number of operations required. We finally demonstrate that for a given history graph GG, a finite set of AVGs describe all parsimonious interpretations of GG, and this set can be explored with a few sampling moves.Comment: 52 pages, 24 figure

    The fate of steroid estrogens: Partitioning during wastewater treatment and onto river sediments

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 Springer Science+Business Media B.V.The partitioning of steroid estrogens in wastewater treatment and receiving waters is likely to influence their discharge to, and persistence in, the environment. This study investigated the partitioning behaviour of steroid estrogens in both laboratory and field studies. Partitioning onto activated sludge from laboratory-scale Husmann units was rapid with equilibrium achieved after 1 h. Sorption isotherms and Kd values decreased in the order 17α-ethinyl estradiol > 17α-estradiol > estrone > estriol without a sorption limit being achieved (1/n >1). Samples from a wastewater treatment works indicated no accumulation of steroid estrogens in solids from primary or secondary biological treatment, however, a range of steroid estrogens were identified in sediment samples from the River Thames. This would indicate that partitioning in the environment may play a role in the long-term fate of estrogens, with an indication that they will be recalcitrant in anaerobic conditions.EPSR

    T-Cell Memory Responses Elicited by Yellow Fever Vaccine are Targeted to Overlapping Epitopes Containing Multiple HLA-I and -II Binding Motifs

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    The yellow fever vaccines (YF-17D-204 and 17DD) are considered to be among the safest vaccines and the presence of neutralizing antibodies is correlated with protection, although other immune effector mechanisms are known to be involved. T-cell responses are known to play an important role modulating antibody production and the killing of infected cells. However, little is known about the repertoire of T-cell responses elicited by the YF-17DD vaccine in humans. In this report, a library of 653 partially overlapping 15-mer peptides covering the envelope (Env) and nonstructural (NS) proteins 1 to 5 of the vaccine was utilized to perform a comprehensive analysis of the virus-specific CD4+ and CD8+ T-cell responses. The T-cell responses were screened ex-vivo by IFN-γ ELISPOT assays using blood samples from 220 YF-17DD vaccinees collected two months to four years after immunization. Each peptide was tested in 75 to 208 separate individuals of the cohort. The screening identified sixteen immunodominant antigens that elicited activation of circulating memory T-cells in 10% to 33% of the individuals. Biochemical in-vitro binding assays and immunogenetic and immunogenicity studies indicated that each of the sixteen immunogenic 15-mer peptides contained two or more partially overlapping epitopes that could bind with high affinity to molecules of different HLAs. The prevalence of the immunogenicity of a peptide in the cohort was correlated with the diversity of HLA-II alleles that they could bind. These findings suggest that overlapping of HLA binding motifs within a peptide enhances its T-cell immunogenicity and the prevalence of the response in the population. In summary, the results suggests that in addition to factors of the innate immunity, "promiscuous" T-cell antigens might contribute to the high efficacy of the yellow fever vaccines. © 2013 de Melo et al

    Evaluation of rK39 rapid diagnostic tests for canine visceral leishmaniasis : longitudinal study and meta-analysis

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    Canine visceral leishmaniasis is a vector-borne disease caused by the intracellular parasite Leishmania infantum. It is an important veterinary disease, and dogs are also the main animal reservoir for human infection. The disease is widespread in the Mediterranean area, and parts of Asia and South and Central America, and is potentially fatal in both dogs and humans unless treated. Diagnosis of canine infections requires serological or molecular tests. Detection of infection in dogs is important prior to treatment, and in epidemiological studies and control programmes, and a sensitive and specific rapid diagnostic test would be very useful. Rapid diagnostic tests (RDTs) have been developed, but their diagnostic performance has been reported to be variable. We evaluated the sensitivity of a RDT based on serological detection of the rK39 antigen in a cohort of naturally infected Brazilian dogs. The sensitivity of the test to detect infection was relatively low, but increased with time since infection and the severity of infection. We then carried out a meta-analysis of published studies of rK39 RDTs, evaluating the sensitivity to detect disease and infection. The results suggest that rK39 RDTs may be useful in a veterinary clinical setting, but the sensitivity to detect infection is too low for operational control programmes
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