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排序方式: 共有520条查询结果,搜索用时 31 毫秒
161.
Diana Amado Fernando Del Villar Francisco Miguel Leo David Sánchez-Oliva Pedro Antonio Sánchez-Miguel Tomás García-Calvo 《PloS one》2014,9(1)
This research study purports to verify the effect produced on the motivation of physical education students of a multi-dimensional programme in dance teaching sessions. This programme incorporates the application of teaching skills directed towards supporting the needs of autonomy, competence and relatedness. A quasi-experimental design was carried out with two natural groups of 4th year Secondary Education students - control and experimental -, delivering 12 dance teaching sessions. A prior training programme was carried out with the teacher in the experimental group to support these needs. An initial and final measurement was taken in both groups and the results revealed that the students from the experimental group showed an increase of the perception of autonomy and, in general, of the level of self-determination towards the curricular content of corporal expression focused on dance in physical education. To this end, we highlight the programme''s usefulness in increasing the students'' motivation towards this content, which is so complicated for teachers of this area to develop. 相似文献
162.
Natalie Villar Freret-Meurer Amanda do Carmo Vaccani Gabriela dos Santos Cabiró 《Journal of fish biology》2021,99(2):695-699
Intersex has been reported regularly in wild populations of gonochoristic fish. The authors investigated the possible feminization of seahorses in a population of Hippocampus reidi in Brazil, as well as report a case of a brood pouch reduction after reproductive stimuli. The female seahorses of this population showed two kinds of morphological anomalies. The proportion of the animals affected in the study population was consistent and was uncorrelated with the sex ratio. The study indicates the changes in the sexual profile of the individual. 相似文献
163.
Burns KE Adhikari NK Slutsky AS Guyatt GH Villar J Zhang H Zhou Q Cook DJ Stewart TE Meade MO 《PloS one》2011,6(1):e14623
Background
Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are life threatening clinical conditions seen in critically ill patients with diverse underlying illnesses. Lung injury may be perpetuated by ventilation strategies that do not limit lung volumes and airway pressures. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing pressure and volume-limited (PVL) ventilation strategies with more traditional mechanical ventilation in adults with ALI and ARDS.Methods and Findings
We searched Medline, EMBASE, HEALTHSTAR and CENTRAL, related articles on PubMed™, conference proceedings and bibliographies of identified articles for randomized trials comparing PVL ventilation with traditional approaches to ventilation in critically ill adults with ALI and ARDS. Two reviewers independently selected trials, assessed trial quality, and abstracted data. We identified ten trials (n = 1,749) meeting study inclusion criteria. Tidal volumes achieved in control groups were at the lower end of the traditional range of 10–15 mL/kg. We found a clinically important but borderline statistically significant reduction in hospital mortality with PVL [relative risk (RR) 0.84; 95% CI 0.70, 1.00; p = 0.05]. This reduction in risk was attenuated (RR 0.90; 95% CI 0.74, 1.09, p = 0.27) in a sensitivity analysis which excluded 2 trials that combined PVL with open-lung strategies and stopped early for benefit. We found no effect of PVL on barotrauma; however, use of paralytic agents increased significantly with PVL (RR 1.37; 95% CI, 1.04, 1.82; p = 0.03).Conclusions
This systematic review suggests that PVL strategies for mechanical ventilation in ALI and ARDS reduce mortality and are associated with increased use of paralytic agents. 相似文献164.
Pino-Yanes M Corrales A Basaldúa S Hernández A Guerra L Villar J Flores C 《PloS one》2011,6(3):e18389
Background
Despite the limited genetic heterogeneity of Spanish populations, substantial evidences support that historical African influences have not affected them uniformly. Accounting for such population differences might be essential to reduce spurious results in association studies of genetic factors with disease. Using ancestry informative markers (AIMs), we aimed to measure the African influences in Spanish populations and to explore whether these might introduce statistical bias in population-based association studies.Methodology/Principal Findings
We genotyped 93 AIMs in Spanish (from the Canary Islands and the Iberian Peninsula) and Northwest Africans, and conducted population and individual-based clustering analyses along with reference data from the HapMap, HGDP-CEPH, and other sources. We found significant differences for the Northwest African influence among Spanish populations from as low as ≈5% in Spanish from the Iberian Peninsula to as much as ≈17% in Canary Islanders, whereas the sub-Saharan African influence was negligible. Strikingly, the Northwest African ancestry showed a wide inter-individual variation in Canary Islanders ranging from 0% to 96%, reflecting the violent way the Islands were conquered and colonized by the Spanish in the XV century. As a consequence, a comparison of allele frequencies between Spanish samples from the Iberian Peninsula and the Canary Islands evidenced an excess of markers with significant differences. However, the inflation of p-values for the differences was adequately controlled by correcting for genetic ancestry estimates derived from a reduced number of AIMs.Conclusions/Significance
Although the African influences estimated might be biased due to marker ascertainment, these results confirm that Northwest African genetic footprints are recognizable nowadays in the Spanish populations, particularly in Canary Islanders, and that the uneven African influences existing in these populations might increase the risk for false positives in association studies. Adjusting for population stratification assessed with a few dozen AIMs would be sufficient to control this effect. 相似文献165.
Nilton Ghiotti de Siqueira Cláudia Maria Villar Maziero de Siqueira Rosangela Rodrigues-Silva Manoel do Carmo P Soares Marinete Marins Póvoa 《Memórias do Instituto Oswaldo Cruz》2013,108(5):533-540
The lack of knowledge regarding polycystic hydatid disease results in
delayed or even incorrect diagnosis. The lack of systematic information
regarding treatment also makes it difficult to assess the results and prognosis
in patients with peritoneal and hepatic lesions caused by Echinococcus
vogeli. Here we describe the clinical features of patients, propose
a radiological classification protocol and describe a therapeutic option for the
treatment of hydatid disease that previously had only been used for cases of
cystic echinococcosis (Echinococcus granulosus). A prospective
cohort study was initiated in 1999 and by 2009 the study included 60 patients.
These patients were classified according to the PNM classification (parasite
lesion, neighbouring organ invasion and metastases) and placed in one of three
therapeutic modalities: (i) chemotherapy with albendazole at a dose of 10
mg/kg/day, (ii) surgical removal of cysts or (iii) percutaneous puncture of the
cysts via puncture, aspiration, injection and re-aspiration (PAIR). The results
were stratified according to therapeutic outcome: "cure", "clinical
improvement", "no improvement", "death" or "no information". The PNM
classification was useful in indicating the appropriate therapy in cases of
polycystic hydatid disease. In conclusion, surgical therapy produced the best
clinical results of all the therapies studied based on "cure" and "clinical
improvement" outcomes. The use of PAIR for treatment requires additional
study. 相似文献
166.
Fernand VE Losso JN Truax RE Villar EE Bwambok DK Fakayode SO Lowry M Warner IM 《Chemico-biological interactions》2011,192(3):19-232
Hypoxia is a hallmark of solid tumors, including breast cancer, and the extent of tumor hypoxia is associated with treatment resistance and poor prognosis. Considering the limited treatment of hypoxic tumor cells and hence a poor prognosis of breast cancer, the investigation of natural products as potential chemopreventive anti-angiogenic agents is of paramount interest. Rhein (4,5-dihydroxyanthraquinone-2-carboxylic acid), the primary anthraquinone in the roots of Cassia alata L., is a naturally occurring quinone which exhibits a variety of biologic activities including anti-cancer activity. However, the effect of rhein on endothelial or cancer cells under hypoxic conditions has never been delineated. Therefore, the aim of this study was to investigate whether rhein inhibits angiogenesis and the viability of hormone-dependent (MCF-7) or -independent (MDA-MB-435s) breast cancer cells in vitro under normoxic or hypoxic conditions. Rhein inhibited vascular endothelial growth factor (VEGF165)-stimulated human umbilical vein endothelial cell (HUVEC) tube formation, proliferation and migration under normoxic and hypoxic conditions. In addition, rhein inhibited in vitro angiogenesis by suppressing the activation of phosphatidylinositol 3-kinase (PI3K), phosphorylated-AKT (p-AKT) and phosphorylated extracellular signal-regulated kinase (p-ERK) but showed no inhibitory effects on total AKT or ERK. Rhein dose-dependently inhibited the viability of MCF-7 and MDA-MB-435s breast cancer cells under normoxic or hypoxic conditions, and inhibited cell cycle in both cell lines. Furthermore, Western blotting demonstrated that rhein inhibited heat shock protein 90alpha (Hsp90α) activity to induce degradation of Hsp90 client proteins including nuclear factor-kappa B (NF-κB), COX-2, and HER-2. Rhein also inhibited the expression of hypoxia-inducible factor-1 alpha (HIF-1α), vascular endothelial growth factor (VEGF165), epidermal growth factor (EGF), and the phosphorylation of inhibitor of NF-κB (I-κB) under normoxic or hypoxic conditions. Taken together, these data indicate that rhein is a promising anti-angiogenic compound for breast cancer cell viability and growth. Therefore, further studies including in vivo and pre-clinical need to be performed. 相似文献
167.
We propose a novel response-adaptive randomization procedure for multi-armed trials with continuous outcomes that are assumed to be normally distributed. Our proposed rule is non-myopic, and oriented toward a patient benefit objective, yet maintains computational feasibility. We derive our response-adaptive algorithm based on the Gittins index for the multi-armed bandit problem, as a modification of the method first introduced in Villar et al. (Biometrics, 71, pp. 969-978). The resulting procedure can be implemented under the assumption of both known or unknown variance. We illustrate the proposed procedure by simulations in the context of phase II cancer trials. Our results show that, in a multi-armed setting, there are efficiency and patient benefit gains of using a response-adaptive allocation procedure with a continuous endpoint instead of a binary one. These gains persist even if an anticipated low rate of missing data due to deaths, dropouts, or complete responses is imputed online through a procedure first introduced in this paper. Additionally, we discuss how there are response-adaptive designs that outperform the traditional equal randomized design both in terms of efficiency and patient benefit measures in the multi-armed trial context. 相似文献
168.
Fanny Buron Paolo Malvezzi Emmanuel Villar Cécile Chauvet Bénédicte Janbon Laure Denis Maria Brunet Sameh Daoud Rémi Cahen Claire Pouteil-Noble Marie-Claude Gagnieu Jacques Bienvenu Fran?ois Bayle Emmanuel Morelon Olivier Thaunat 《PloS one》2013,8(1)
Background
The use of the immunosuppressant sirolimus in kidney transplantation has been made problematic by the frequent occurrence of various side effects, including paradoxical inflammatory manifestations, the pathophysiology of which has remained elusive.Methods
30 kidney transplant recipients that required a switch from calcineurin inhibitor to sirolimus-based immunosuppression, were prospectively followed for 3 months. Inflammatory symptoms were quantified by the patients using visual analogue scales and serum samples were collected before, 15, 30, and 90 days after the switch.Results
66% of patients reported at least 1 inflammatory symptom, cutaneo-mucosal manifestations being the most frequent. Inflammatory symptoms were characterized by their lability and stochastic nature, each patient exhibiting a unique clinical presentation. The biochemical profile was more uniform with a drop of hemoglobin and a concomitant rise of inflammatory acute phase proteins, which peaked in the serum 1 month after the switch. Analyzing the impact of sirolimus introduction on cytokine microenvironment, we observed an increase of IL6 and TNFα without compensation of the negative feedback loops dependent on IL10 and soluble TNF receptors. IL6 and TNFα changes correlated with the intensity of biochemical and clinical inflammatory manifestations in a linear regression model.Conclusions
Sirolimus triggers a destabilization of the inflammatory cytokine balance in transplanted patients that promotes a paradoxical inflammatory response with mild stochastic clinical symptoms in the weeks following drug introduction. This pathophysiologic mechanism unifies the various individual inflammatory side effects recurrently reported with sirolimus suggesting that they should be considered as a single syndromic entity. 相似文献169.
Cabodevilla O Villar E Virto C Murillo R Williams T Caballero P 《Applied and environmental microbiology》2011,77(9):2954-2960
170.
César G. Gomez María V. Pérez Lambrecht Jorge E. Lozano Marguerite Rinaudo Marcelo A. Villar 《International journal of biological macromolecules》2009,44(4):365-371
In this work, three methods (ethanol, HCl, and CaCl2 routes) of sodium alginate extraction–purification from brown seaweeds (Macrocystis pyrifera) were used in order to study the influence of process conditions on final properties of the polymer. In the CaCl2 route, was found that the precipitation step in presence of calcium ions followed by proton-exchange in acid medium clearly gives alginates with the lowest molecular weight and poor mechanical properties. It is well known that the acid treatment degrade the ether bonds on the polymeric chain. Ethanol route displayed the best performance, where the highest yield and rheological properties were attained with the lowest number of steps. Although the polymer I.1 showed a molar mass and polydispersity index (Mw/Mn) similar to those of commercial sample, its mechanical properties were lower. This performance is related to the higher content of guluronic acid in the commercial alginate, which promotes a more successful calcium chelation. Moreover, the employment of pH 4 in the acid pre-treatment improved the yield of the ethanol route, avoiding the ether linkage hydrolysis. Therefore, samples I.2 and I.3 displayed a higher Mw and a narrower distribution of molecular weights than commercial sample, which gave a higher viscosity and better viscoelastic properties. 相似文献