131 research outputs found

    Pressure effects on the structural and superconducting transitions in La₃Co₄Sn₁₃

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    La3Co4Sn13 is a superconducting material with transition temperature at Tc = 2.70 K, which presents a superlattice structural transition at T ∗ ≃ 150 K, a common feature for this class of compounds. However, for this material, it is not clear that at T ∗ the lattice distortions arise from a charge density wave (CDW) or from a distinct microscopic origin. Interestingly, it has been suggested in isostructural non-magnetic intermetallic compounds that T ∗ can be suppressed to zero temperature, by combining chemical and external pressure, and a quantum critical point is argued to be observed near these critical doping/pressure. Our study shows that application of pressure on single-crystalline La3Co4Sn13 enhances Tc and decreases T ∗ . We observe thermal hysteresis loops for cooling/heating cycles around T ∗ for P & 0.6 GPa, in electrical resistivity measurements, which are not seen in x-ray diffraction data. The hysteresis in electrical measurements may be due to the pinning of the CDW phase to impurities/defects, while the superlattice structural transition maintains its ambient pressure second-order transition nature under pressure. From our experiments we estimate that T ∗ vanishes at around 5.5 GPa, though no quantum critical behavior is observed up to 2.53 GPa

    The effect of delayed graft function on graft and patient survival in kidney transplantation: an approach using competing events analysis

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    OBJECTIVE: In kidney transplantation, the impact of delayed graft function (DGF) on long-term graft and patient survival is controversial. We examined the impact of DGF on graft and recipient survival by accounting for the possibility that death with graft function may act as a competing risk for allograft failure. STUDY DESIGN AND SETTING: We used data from 1281 adult primary deceased-donor kidney recipients whose allografts functioned at least 1 year. RESULTS: The probability of graft loss occurrence is overestimated using the complement of Kaplan-Meier estimates (1-KM). Both the cause-specific Cox proportional hazard regression model (standard Cox) and the subdistribution hazard regression model proposed by Fine and Gray showed that DGF was associated with shorter time to graft failure (csHR = 2.0, P = 0.002; sHR = 1.57, P = 0.009), independent of acute rejection (AR) and after adjusting for traditional factors associated with graft failure. Regarding patient survival, DGF was a predictor of patient death using the cause-specific Cox model (csHR = 1.57, P = 0.029) but not using the subdistribution model. CONCLUSIONS: The probability of graft loss from competing end points should not be reported with the 1-KM. Application of a regression model for subdistribution hazard showed that, independent of AR, DGF has a detrimental effect on long-term graft survival, but not on patient survival

    Medicinal animals used in ethnoveterinary practices of the 'Cariri Paraibano', NE Brazil

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    <p>Abstract</p> <p>Background</p> <p>Zootherapy is important in various socio-cultural environments, and innumerous examples of the use of animal derived remedies can currently be found in many urban, semi-urban and more remote localities in all parts of the world, particularly in developing countries. However, although a number of ethnobiological inventories concerning the use of medicinal animals in human health care have been compiled in Brazil in recent years, zootherapeutic practices in ethnoveterinary medicine (EVM) are poorly described and neglected in favor of human ethnomedicine. In this sense, the purpose of this study was to describe the local zootherapeutic practices in ethnoveterinary medicine of semi-arid of NE Brazil (Caatinga biome) and to contribute to future research about the validation of the effects and side effects of these animal products</p> <p>Methods</p> <p>The information obtained through semi-structured interviews was complemented by free interviews and informal conversations. A total of 67 people were interviewed (53 men and 14 women) about the use and commercialization of medicinal animals. To determine the relative importance of each local known species, their use-values (UV) were calculated. Diversity of species utilized was compared, between localities, using rarefaction curves and diversity estimate (Chao2)</p> <p>Results and Conclusions</p> <p>A total of 44 animal species (37 vertebrates and 7 invertebrates), distributed among 6 taxonomic categories were found to be used to treat 30 different ailments in livestock and pets. The results of our surveys revealed a rich traditional knowledge of local residents about the use of animals in traditional veterinary medicine. Although it is gradually being discontinued, the perceived efficacy, economic and geographic accessibility were main reasons for popularity of zootherapy in studied areas.</p

    Oxidative Stress in Kidney Transplantation: Malondialdehyde Is an Early Predictive Marker of Graft Dysfunction

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    Background Oxidative stress is one of the most important components of the ischemia-reperfusion process after kidney transplantation (KTx) and increases with graft dysfunction. Methods This prospective study was conducted on 40 consecutive KTx recipients to evaluate time-dependent changes in oxidative stress-related parameters within the first week after KTx and to assess their performance in predicting delayed graft function (DGF=dialysis requirement during initial posttransplant week) and graft function at 1 year. Blood samples were collected before (day 0) and after KTx (days 1, 2, 4, and 7). Total antioxidant capacity, plasma levels of malondialdehyde (MDA), and activities of glutathione peroxidase, glutathione reductase and superoxide dismutase were measured. Multivariable linear mixed and linear regression models, receiver-operating characteristic (ROC), and areas under ROC curves (AUC-ROC) were used. Results At all time points after KTx, mean MDA levels were significantly higher in patients developing DGF (n=18). Shortly after KTx (8–12 hr), MDA values were higher in DGF recipients (on average, +0.16 μmol/L) and increased further on following day, contrasting with prompt functioning recipients. Day 1 MDA levels accurately predicted DGF (AUC-ROC=0.90), with a performance higher than SCr (AUC-ROC=0.73) and similar to cystatin C (AUC-ROC=0.91). Multivariable analysis revealed that MDA levels on day 7 represented an independent predictor of 1-year graft function. Antioxidant enzyme activities were not significantly changed during the study period and were not predictors of 1-year graft function. Conclusions Increased MDA levels on day 1 after KTx might be an early prognostic indicator of DGF, and levels on day 7 might represent a useful predictor of 1-year graft function

    Leptin and adiponectin during the first week after kidney transplantation: biomarkers of graft dysfunction?

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    CONTEXT AND OBJECTIVE: Based on evidence that leptin and adiponectin are removed from circulation primarily by the kidney, we designed a study to examine the longitudinal changes of these adipokines during the first week after kidney transplantation (KTx) and to test the hypothesis that higher levels of leptin and/or adiponectin could be early biomarkers of delayed graft function (DGF=dialysis requirement during the first post-transplant week) and acute rejection. STUDY DESIGN: Repeated-measures prospective study. MATERIAL AND METHODS: Forty consecutive adult patients with end-stage renal disease who were undergoing KTx. Leptin and adiponectin were measured in blood samples that were collected before (day-0) and after KTx (days-1, 2, 4 and 7). Linear mixed-models, receiver operating characteristic and area under curve (AUC-ROC) were used. RESULTS: At post-transplant day-1, leptinemia and adiponectinemia declined 43% and 47%, respectively. At all times studied after KTx, the median leptin levels were significantly higher in patients developing DGF (n=18), but not adiponectin levels. Shortly after KTx (day-1), leptin values were significantly higher in DGF recipients in contrast to patients with promptly functioning kidneys, approximately two times higher when controlling for gender and BMI. The leptin reduction rate between pre-tranplant and one-day after KTx moderately predicted DGF (AUC=0.73). On day-1, serum leptin predicted DGF (AUC-ROC=0.76) with a performance slightly better than serum creatinine (AUC-ROC=0.72), even after correcting for BMI (AUC-ROC=0.73). Separating this analysis by gender showed that the performance of leptin in predicting DGF for male gender (AUC-ROC=0.86) improved. CONCLUSIONS: Kidney graft function is an independent determinant of leptin levels, but not of adiponectin. Leptin levels at day-1 slightly outperformed serum creatinine in predicting the occurrence of DGF, and more accurately in male gender. No significant association was detected with acute rejection

    Meaning of leprosy for people who have experienced treatment during the sulfonic and multidrug therapy periods

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    Objetivo:analizar los significados de la lepra para las personas que fueron tratadas en el período sulfónico y en el período de poliquimioterapia.Método:estudio de naturaleza cualitativa fundamentado en el abordaje histórico cultural de Vygotsky, el cual orientó la construcción y análisis de los datos. Fueron incluidos ocho entrevistados que ya tuvieron lepra y que realizaron tratamiento en el período sulfónico y de poliquimioterapia, siendo participantes del Movimiento de Reintegración de Personas Afectadas por la Lepra.Resultados:los significados fueron organizados en tres núcleos de significación: manchas en el cuerpo: alguna cosa está fuera de orden; ¿Lepra o enfermedad de Hansen?; y lepra a partir de la inserción en el Movimiento de Reintegración de Personas Afectadas por la Lepra. Conclusión: los significados de la lepra para las personas tratadas en los dos períodos apuntan para la construcción compleja de los mismos, indicando diferencias y semejanzas en los dos períodos. Los profesionales de la salud pueden contribuir para el cambio de significados, ya que estos son socialmente construidos y las transformaciones son continuas.Objetivo:analisar significados da hanseníase para as pessoas que foram tratadas no período sulfônico e no período da poliquimioterapia.Método:estudo de natureza qualitativa fundamentado na abordagem histórico-cultural de Vigotski, a qual orientou a construção e análise dos dados. Foram incluídos oito entrevistados que já tiveram hanseníase e que realizaram tratamento no período sulfônico e da poliquimioterapia, sendo participantes do Movimento de Reintegração das Pessoas Atingidas pela Hanseníase.Resultados:os significados foram organizados em três núcleos de significação: manchas no corpo: alguma coisa está fora de ordem; lepra ou hanseníase? e hanseníase a partir da inserção no Movimento de Reintegração das Pessoas Atingidas pela Hanseníase.Conclusão:os significados de hanseníase para pessoas tratadas nos dois períodos apontam para a construção complexa dos mesmos, indicando diferenças e semelhanças nos dois períodos. Os profissionais de saúde podem contribuir para a mudança de significados, pois esses são socialmente construídos e as transformações são contínuas.Objective: to analyze the meanings of leprosy for people treated during the sulfonic and multidrug therapy periods.Method: qualitative nature study based on the Vigotski's historical-cultural approach, which guided the production and analysis of data. It included eight respondents who have had leprosy and were submitted to sulfonic and multidrug therapy treatments. The participants are also members of the Movement for Reintegration of People Affected by Leprosy.Results: the meanings were organized into three meaning cores: spots on the body: something is out of order; leprosy or hanseniasis? and leprosy from the inclusion in the Movement for Reintegration of People Affected by Leprosy.Conclusion: the meanings of leprosy for people submitted to both regimens point to a complex construction thereof, indicating differences and similarities in both treatments. Health professionals may contribute to the change of the meanings, since these are socially constructed and the changes are continuous

    A first AFLP-based genetic linkage map for brine shrimp Artemia franciscana and its application in mapping the sex locus

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    We report on the construction of sex-specific linkage maps, the identification of sex-linked markers and the genome size estimation for the brine shrimp Artemia franciscana. Overall, from the analysis of 433 AFLP markers segregating in a 112 full-sib family we identified 21 male and 22 female linkage groups (2n = 42), covering 1,041 and 1,313 cM respectively. Fifteen putatively homologous linkage groups, including the sex linkage groups, were identified between the female and male linkage map. Eight sex-linked AFLP marker alleles were inherited from the female parent, supporting the hypothesis of a WZ-ZZ sex-determining system. The haploid Artemia genome size was estimated to 0.93 Gb by flow cytometry. The produced Artemia linkage maps provide the basis for further fine mapping and exploring of the sex-determining region and are a possible marker resource for mapping genomic loci underlying phenotypic differences among Artemia species
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