Effect of Microwave-Assisted Synthesis and Sintering of Lead-Free KNL-NTS Ceramics

Lead-free piezoelectric powders (K_0.44Na_0.52Li_0.04)(Nb_0.82Ta_0.10Sb_0.04)O₃ were obtained by conventional and microwave-assisted reactive heating. Firstly, the synthesis of the material was carried out following the mixed oxide route and employing both traditional methods and microwave technology. Thermogravimetry, X-ray diffraction, field emission scanning electron microscopy and electrical properties analyses were evaluated. X-ray diffraction of the powders calcined by the microwave process shows the formation of perovskite structure with orthorhombic geometry, but it is possible to observe the presence of other phases. The presence of the secondary phases found can have a great influence on the heating rate during the synthesis on which the kinetics of the reaction of formation of the piezoelectric compound depend. The calcined powder was sintered at different temperatures by conventional and non-conventional processes. The microstructure of the ceramics sintered by microwave at 1050 °C for 10 min shows perovskite cubes with regular geometry, of size close to 2–5 µm. However, the observed porosity (~8%), the presence of liquid phase and secondary phases in the microstructure of the microwave sintered materials lead to a decrease of the piezoelectric constant. The highest d₃₃ value of 146 pC/N was obtained for samples obtained by conventional at 1100 °C 2 h compared to samples sintered by microwave at 1050 °C 10 min (~15 pC/N).     

Time trends in health inequalities due to care in the context of the Spanish Dependency Law

Objective

In Spain, responsibility for care of old people and those in situations of dependency is assumed by families, and has an unequal social distribution according to gender and socioeconomic level. This responsibility has negative health effects on the carer. In 2006, the Dependency Law recognised the obligation of the State to provide support. This study analyses time trends in health inequalities attributable to caregiving under this new law.

The effects of acute and chronic administration of morphine on the turnover of brain and adrenal catecholamines in rats

Brain and adrenal catecholamine turnover in adult female rats treated with morphine was investigated. A different time course response of brain and adrenal catecholamines to -methyl-p-tyrosine methylester (AMT) administration in normal rats was observed; the catecholamine turnover rate in adrenal glands appeared to be much slower than in the brain. Acute morphine increased the turnover of brain dopamine and noradrenaline as well as of adrenal catecholamines, whereas chronic morphine treatment induced a decrease in the turnover of brain noradrenaline. Withdrawal induced by nalorphine produced an increase in the utilization of brain noradrenaline and adrenal catecholamines; this effect could be related to the withdrawal stress situation induced by the opiate antagonist. Although the mechanism of morphine action may implicate other neurotransmitters besides catecholamines, our results contribute to evidence that brain and adrenal catecholamines could be involved in the mechanism of morphine tolerance and/or dependence.     

Transfer of Function to a Specific Area of the Cortex After Induced Recovery from Brain Damage

Different methods of inducing recovery after brain damage and different mechanisms that might mediate the induced recovery have been proposed. One possible mechanism involves the ability of one part of the brain to take over the function of another. We show here in rats that (1) bar-pressing behaviour to eliminate an aversive stimulus, which becomes dramatically impaired after bilateral lesion of the frontal primary motor - sensory cortex, is recovered when the animals receive an electrical intracranial stimulation in the ventral tegmental nucleus of the brain contingent on an adequate response during performance in the behavioural task, (2) in recovered animals an area in the posterior primary motor – sensory cortex, the hindlimb motor - sensory cortex, shows a 35% increase in the number of fos-like immunoreactive cells compared to non-recovered animals, and (3) a bilateral lesion of this area in recovered animals reinstates the impairment in the performance of the behavioural task. These results indicate that an area of the cerebral cortex is able to assume the role of another area after induced recovery from brain damage.     

Cancer Knowledge Increases After a Brief Intervention Among Arab Americans in Michigan

The objective of this study was to examine which factors are associated with increased cancer knowledge among a sample of 866 Arab Americans 40 years of age or older. Individuals were invited to attend a cancer educational intervention and obtain a free cancer health screening. They were asked to complete a precancer and postcancer knowledge survey after the brief educational intervention. Using logistic regression, we found that the intervention increased cancer knowledge and the variables most associated with this improvement were having low education, being unemployed, having lived in the USA for 0–5 years, older age, not having insurance, and not exercising. Our study showed that these interventions may be more effective if tailored to the participant’s educational, employment, duration in the US, and health behavior status. Future studies should examine whether cancer screening actually increases after an educational intervention.     

研究诊断准确性的论著的质量:STARD公布后无改变——STARD公布前后的比较研究

目的确定对诊断准确性进行研究的论著的规范(STARD)公布前、后该类论著的质量改善情况,并比较执行STARD和未执行STARD的杂志的该类论著质量有无差     

Effects of contact location and voltage amplitude on speech and movement in bilateral subthalamic nucleus deep brain stimulation

Subthalamic nucleus deep brain stimulation (STN‐DBS) is particularly effective in improving limb symptoms in Parkinson's disease. However, speech shows a variable response. Contact site and amplitude of stimulation have been suggested as possible factors influencing speech. In this double blind study, we assessed 14 patients post bilateral STN‐DBS, without medication. Six conditions were studied in random order as follows: stimulation inside the STN at low voltage (2 V) and at high voltage (4 V); above the STN at 2 V and at 4 V, at usual clinical parameters, and off‐stimulation. The site of stimulation was defined on the postoperative stereotactic MRI data. Speech protocol consisted of the assessment of intelligibility of the dysarthric speech, maximum sustained phonation, and a 1‐minute monologue. Movement was assessed using the UPDRS‐III. Stimulation at 4 V significantly reduced the speech intelligibility (P = 0.004) independently from the site of stimulation. Stimulation at 4 V significantly improved the motor function. Stimulation inside the nucleus was significantly more effective than outside the nucleus (P = 0.0006). The significant improvement in movement coupled with significant deterioration in speech intelligibility when patients are stimulated inside the nucleus at high voltage indicates a critical role for electrical stimulation parameters in speech motor control. © 2008 Movement Disorder Society     

Homozygotes for prothrombin gene 20210 A allele in a thrombophilic family without clinical manifestations of venous thromboembolism.

BACKGROUND AND OBJECTIVE: A new genetic risk factor for venous thromboembolism has recently been described which involves a G to A transition at position 20210 in the 3' untranslated region of the prothrombin gene. To date, only a few homozygotes for this mutation have been reported and in most of cases, they suffered from thrombotic disease. Here, we describe a pedigree including both heterozygous and homozygous subjects for prothrombin (PT) 20210 A. DESIGN AND METHODS: This family was recruited in 1996 as part of our GAIT (Genetic Analysis of Idiopathic Thrombophilia) project. To qualify for the GAIT study, a pedigree was required to have at least 10 living individuals in three or more generations (i.e. extended pedigree). The pedigrees were selected through probands with idiopathic thrombophilia. A complete set of plasma and DNA determinations related to hemostasis was performed on this family. RESULTS: The plasma studies yielded normal results in all of the individuals. The family members who had a history of thromboembolism were heterozygous carriers of the PT 20210 A variant. In addition, 4 relatives who were heterozygous, and two who were homozygous for this A allele, failed to show clinical manifestations. These two homozygotes were 51 and 19 years old. INTERPRETATION AND CONCLUSIONS: This case exemplifies the complexity of thrombotic disease since individuals homozygous for a mutant gene do not exhibit symptoms while heterozygous individuals often do exhibit the disease. This case suggests that the new genetic risk factor for thrombosis (i.e. PT 20210 A) may not be as strong as most of the previously described genetic risk factors.