RESUMEN
Usually, the measurements of electronic and magnetic properties of superconducting samples are carried out under a constant temperature bath. On the other hand, thermal gradients induce local variation of the superconducting order parameter, and the vortex dynamics can present interesting behaviors. In this work, we solved the time-dependent Ginzburg-Landau equations simulating samples under two different thermal gradients, and considering two values of the Ginzburg-Landau parameter, [Formula: see text]. We find that both parameters, i.e. [Formula: see text] and thermal gradients, play an important role on the vortex dynamics and on the magnetization behavior of the samples.
RESUMEN
The manipulation and control of vortex states in superconducting systems are of great interest in view of possible applications, for which mesoscopic materials are good candidates. In this work, we studied the annihilation dynamics and the dissipative aspects of an Abrikosov's vortex-antivortex pair in a mesoscopic superconducting system with a concentric hole. The generalized time-dependent Ginzburg-Landau equations were numerically solved. The main result is the appearance of a phase slip-like line due to the elongation of the vortex and antivortex cores. Under specific circumstances, thermal dissipation might be associated with a sizeable relaxation of the order parameter, so that the energy released in the annihilation of a vortex-antivortex pair might become detectable in measurements of the magnetization as a function of time.
RESUMEN
The rat posterodorsal medial amygdala (MePD) expresses receptors for gonadal hormones and integrates sex steroid-sensitive subcortical networks. Male-female differences are found in the morphology, connectivity, and local neuropil structure of MePD. For example, dendritic spine density is sexually-dimorphic and changes with the estrous cycle and following gonadal hormones manipulations. Due to its connectivity, the MePD may affect emotionally-loaded social behaviors, according to a former Newman's seminal proposition. Unilateral fiber-sparing ibotenic acid damage of the MePD does not impair male sexual behavior. However, microinjecting glutamate and histamine into the right MePD facilitates ejaculation. Further, MePD-lesioned rats are not different from normal rats in anxiety-like behavior as evaluated by the elevated plus maze test or innate fear test induced by a live cat. In another study, an adapted model for inducing aggressive behavior in rats by a brief period of restraint prior to the resident-intruder paradigm was used to study Fos-immunoreactivity in the MePD. Following stressful stimulation (restraint) or the restraint and fight condition, but not after aggression alone, Fos-immunoreactivity was detected in the MePD. Microinjecting the inhibitory neuropeptide somatostatin into the right MePD notably reduces fighting behavior without affecting locomotion. Overall, these data indicate that sex steroids and local neurochemical stimulatory/inhibitory transmitters modulate the MePD and reinforce the idea that this area is a node for modulating social behavior neural networks.
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Amígdala del Cerebelo/anatomía & histología , Amígdala del Cerebelo/fisiología , Hormonas Esteroides Gonadales/metabolismo , Ratas/anatomía & histología , Ratas/fisiología , Agresión , Animales , Miedo , Femenino , Masculino , Conducta Sexual AnimalRESUMEN
Here, we established a program of low-intensity aerobic exercise and compared the effects of exercise preoperative, postoperative, and a combination of both pre- and postoperative protocols on recovery from sciatic nerve crush injury in mice using behavioral, biochemical, and morphological assays. Sciatic nerve crush was performed in adult male mice. The animals were submitted to preoperative (for 2 weeks), postoperative (for 2 weeks), and a combination of preoperative-postoperative (for 4 weeks) training protocols. During the training period, functional recovery was monitored using the Sciatic Functional Index, the Sciatic Static Index, and mechanical and cold hypersensitivity analyses. Morphological and biochemical alterations were analyzed on the 14th day post-crushing. The functional recovery values of all of the exercised groups were significantly better than the nonexercised group. Biochemically, all of the exercise groups showed a reduction in the increase of interleukin-1ß (IL-1ß) in the sciatic nerve and in the IL-1ß and interleukin-6 receptor (IL-6R) levels in the spinal cord. However, the levels of tumor necrosis factor alpha (TNF-α) decreased only in the postoperative group and in the combination exercise protocols. In the morphological analysis, the combination exercise subjects presented an increase in fiber and axon diameter, in the myelination degree and in the number of myelinated fibers. The present study showed that pre- and postoperative exercise achieved values for functional and morphological sciatic nerve regeneration that were significantly better than either the preoperative or postoperative protocols. This experimental study suggests that physical exercise can restore motor and nerve function to a substantial degree when performed using a prophylactic and therapeutic approach.
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Citoprotección/fisiología , Terapia por Ejercicio/métodos , Regeneración Nerviosa/fisiología , Condicionamiento Físico Animal/fisiología , Recuperación de la Función/fisiología , Neuropatía Ciática/fisiopatología , Neuropatía Ciática/terapia , Animales , Modelos Animales de Enfermedad , Masculino , RatonesRESUMEN
BACKGROUND: Tuberculosis remains an important public health problem in Brazil where over 100 000 new cases and 6000 deaths are reported every year. Current drug efficacy and wide availability should have curbed this toll. The goal was to study the factors associated with death in incident cases of pulmonary tuberculosis (PT) during treatment. METHODS: This is a case-control study including all new cases of PT reported between 2000 and 2004; cases were patients who died of any cause and controls were those cured after initial PT treatment. Data analyses included unconditional multiple hierarchical logistic regression. RESULTS: A total of 313 502 new cases of tuberculosis were reported between 2000 and 2004; 224 355 (71.6%) were cured after initial treatment and 20 721 (6.6%) died during the surveillance follow-up. Over 82% of all cases were diagnosed with PT. After controlling for significant variables, the factors associated with a higher risk of death included gender (males: odds ratio (OR) 1.4; 95% confidence interval (CI) 1.33 to 1.47), age (<5 years of age: OR 1.90; 95% CI 1.51 to 2.38; 30-59 years: OR 2.78; 95% CI 2.61 to 2.97; over 60 years: OR 10.92; 95% CI 10.09 to 11.81), positive HIV serology (OR 10.59; 95% CI 9.76 to 11.48), alcoholism (OR 1.49; 95% CI 1.36 to 1.65), mental disorder (OR 1.80; 95% CI 1.43 to 2.27) and presence of additional lung pathology on chest x ray (OR 2.22; 95% CI 1.83 to 2.70). Protective variables included education (highest level: OR 0.67; 95% CI 0.63 to 0.70). CONCLUSIONS: Preventive interventions should target the most vulnerable patients, in particular the very young and the elderly, those infected with HIV and those presenting with a mental disorder or additional lung pathology.
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Tuberculosis Pulmonar/mortalidad , Infecciones Oportunistas Relacionadas con el SIDA/mortalidad , Adolescente , Adulto , Factores de Edad , Anciano , Antituberculosos/uso terapéutico , Brasil/epidemiología , Niño , Preescolar , Métodos Epidemiológicos , Femenino , Humanos , Enfermedades Pulmonares/mortalidad , Masculino , Trastornos Mentales/mortalidad , Persona de Mediana Edad , Pronóstico , Factores Sexuales , Factores Socioeconómicos , Resultado del Tratamiento , Tuberculosis Pulmonar/tratamiento farmacológico , Adulto JovenRESUMEN
The ring-infected erythrocyte surface antigen (RESA), is one of the falciparum malaria vaccine candidates rarely studied in Brazil. Fieldwork logistics to conduct serology studies is simplified when eluates from whole blood dried on filter paper can be used. Therefore, this study aimed to assess the inter-test reliability for the anti-RESA ELISA-based indices using eluates from filter paper and from serum samples. The study population consisted of 210 individuals (Brazil) from whom matched samples were collected. Anti-RESA ELISA-based index means (+/- S.D.) were 15.29% (+/-28.13%) for filter paper and 11.79% (+/-23.67%) for serum samples. The intra-class correlation coefficient was estimated to be 82.38%, indicating high test reliability. However, there was a significant tendency for filter paper test results to have higher values than serum sample test results (P < 0.001). Explanations for this finding may be the presence of haemoglobin in the eluates from filter paper, which may interfere with ELISA testing.
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Anticuerpos Antiprotozoarios/sangre , Plasmodium falciparum/inmunología , Proteínas Protozoarias/inmunología , Adolescente , Adulto , Animales , Niño , Preescolar , Ensayo de Inmunoadsorción Enzimática , Femenino , Filtración , Humanos , Lactante , Masculino , Persona de Mediana EdadRESUMEN
This study evaluated the cure rate of the standard recommended regimen for Plasmodium vivax malaria in Brazil and assessed risk factors for failures. Fifty patients with vivax malaria given supervised medical treatment (standard dose of chloroquine: total dose = 1.5 g over a three-day period plus primaquine: total dose = 210 mg over a 14-day period) were followed for six months in a non-endemic area. Cox's regression was used to identify predictors of relapses. Among the 289 patient-months of follow-up, seven relapses were identified (2.4 relapses per 100 person-months) between 33 and 137 days after treatment initiation. Risk factors for relapses (P < or = 0.05) were female sex, higher parasitemia at baseline, shorter number of days with symptoms prior to baseline, and lower mg/kg dose of primaquine. Relapses following supervised vivax treatment is in principle a necessary, but not sufficient, component of in vivo parasite resistance. Results indicate that other factors, principally sub-therapeutic primaquine doses, may explain the occurrence of vivax treatment failures.
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Antimaláricos/administración & dosificación , Cloroquina/administración & dosificación , Malaria Vivax/tratamiento farmacológico , Primaquina/administración & dosificación , Adolescente , Adulto , Anciano , Esquema de Medicación , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Recurrencia , Factores de Riesgo , Insuficiencia del TratamientoRESUMEN
A triple-blind, randomized, clinical trial was undertaken in a Brazilian Amazon region to compare the effectiveness of oral artesunate (seven days, total dose = 0.75 g) plus tetracycline (seven days, total dose = 10.5 g) (AT) and oral quinine (three days, total dose = 6 g) plus tetracycline (seven days, total dose = 10.5 g) (QT) against uncomplicated Plasmodium falciparum malaria. Effectiveness was assessed by cure rates (World Health Organization [WHO]) and parasite clearance at day 2. Patients were randomized, 88 to each group. The groups had similar baseline clinical characteristics. The incidence of side effects was much higher in the QT group (82%) than in the AT group (50%) (P < 0.001). Cure rates were similar: 80% in the AT group and 77% in the QT group (P = 0.68). Parasitemia (by day 2) cleared faster in the AT group than in the QT group (98.5% versus 47.6%, respectively; P < 0.001). These results indicate that the combination of artesunate plus tetracycline is effective in the treatment of uncomplicated falciparum malaria and may provide a useful alternative to other treatment regimens.