Rats with caudate lesions and pretrained for 36 trials demonstrated impaired performance on the "reference memory" or invariant aspect of a 12-arm maze and normal performance on the "working memory" or variable aspect of the maze. Rats with caudate lesions and no pretraining were also impaired on an invariant tactile discrimination in a T maze, but they were not impaired on the variable goal-arm choice of the T maze. More extensive preoperative training ameliorated behavioral deficits of rats with caudate lesions in the T maze and radial arm maze. Results showed that behavioral impairment after damage to the caudate is not restricted to egocentric tasks as previously suggested, but the caudate seems to be involved in the initial acquisition that is invariant over many trials. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
In 1991, a novel robot, MIT-MANUS, was introduced to study the potential that robots might assist in and quantify the neuro-rehabilitation of motor function. MIT-MANUS proved an excellent tool for shoulder and elbow rehabilitation in stroke patients, showing in clinical trials a reduction of impairment in movements confined to the exercised joints. This successful proof of principle as to additional targeted and intensive movement treatment prompted a test of robot training examining other limb segments. This paper focuses on a robot for wrist rehabilitation designed to provide three rotational degrees-of-freedom. The first clinical trial of the device will enroll 200 stroke survivors. Ultimately 160 stroke survivors will train with both the proximal shoulder and elbow MIT-MANUS robot, as well as with the novel distal wrist robot, in addition to 40 stroke survivor controls. So far 52 stroke patients have completed the robot training (ongoing protocol). Here, we report on the initial results on 36 of these volunteers. These results demonstrate that further improvement should be expected by adding additional training to other limb segments. 相似文献
Retrospective childhood attention-deficit/hyperactivity disorder (ADHD) symptoms are required to diagnosis adult ADHD, but the validity of self-rated symptoms across time is questionable. Here, boys with ADHD-related problems, their brothers without ADHD, and former schoolmates rated themselves during young adulthood for ages 9, 14, and 19. Brothers rated probands retrospectively at the same ages. The young adults referred as children for ADHD (a) acknowledged childhood symptoms; (b) described improvement over time; (c) did not differ from brothers or controls on most self-ratings of young adult symptoms; (d) rated themselves as more symptomatic at age 9, but less symptomatic at age 19, than their brothers rated them; and (e) agreed only to some degree with brothers' ratings of probands' aggression (median correlation = .22). Probands' ratings showed limited agreement with judges' symptom ratings (median correlation = .16) and young adult follow-up examiners' ratings (median correlation = .14). These findings are not accounted for solely by changes in informants, nor by the course of ADHD psychopathology. They suggest some stability but limited internal consistency and validity for retrospective ADHD ratings by probands and brothers. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
To assess diamond-based semiconducting devices, a reduction of point defect levels and an accurate control of doping are required as well as the control of layer thickness. Among the analyses required to improve such parameters, cross sectional studies should take importance in the near future. The present contribution shows how FIB (focused ion beam) preparations followed by electron microscopy related techniques as TEM or CL allowed to perform analysis versus depth in the layer, doping and point defect levels. Three samples grown along the same week in the same machine with identical growth conditions but on different substrates (CVD-IIIa (110) oriented, CVD-optical grade (100) oriented and a HPHT-Ib (100) oriented) are studied. Even though A-band is observed by CL, no dislocation is observed by CTEM. Point defect type and level are shown to substantially change with respect to the substrate type as well as the boron doping levels that vary within an order of magnitude. H3 present in the epilayer grown on HPHT type of substrate is replaced by T1 and NE3 point defects for epilayers grown on the CVD type one. An increase of excitonic transitions through LO phonons is also shown to take place near the surface while only TO ones are detected deeper in the epilayer. Such results highlight the importance of choosing the correct substrate. 相似文献
Iron plays an important role, not only in oxygen delivery to the tissues, but also as a cofactor with several enzymes involved in energy metabolism and thermoregulation. As a result, much research has been dedicated to understanding the ramifications of iron depletion and iron deficiency anemia on the physiological functions of these enzymes. There is evidence to suggest that iron depletion and iron deficiency anemia cause physiological changes in the body not only during exercise, but also under resting conditions. Both rat and human studies have produced results revealing elevated levels of norepinephrine in the blood and urine of iron-deficient anemic subjects. These studies also provide evidence to suggest that elevation in metabolic rate may ultimately lead to slower growth rates and lower body weights in iron-deficient anemic animals and humans. The focus of this review is on the effects of iron deficiency on metabolic rate and thermoregulation. Prior to this discussion, a brief background on iron is presented. 相似文献
In an earlier publication (Grasselli et al., Top Catal 54:595, 2011) [1] we analyzed the distribution of key catalytic elements at the active site of the M1 phase of the MoVNbTeOx catalyst system based on the definition of this center put forth in our original work (Grasselli et al., Top Catal 23:5, 2003) [2]. From that analysis we derived the probabilities of the metal element distributions at the active center and its immediate surroundings, and based on those results, proposed a model for propane ammoxidation on M1. Recently, the occupancies and concomitant charges of the various elements of the M1 phase have been revised (Li et al., Top Catal 54:614, 2011) [3]. Based on this revised structural model we have now recalculated the elemental probabilities at the active center and its immediate surroundings, and describe here the catalytic consequences in the ammoxidation mechanism of propane that these changes portend. Our revised model (REV) predicts more closely the actual experimental results of propane ammoxidation over MoVNbTeOx than does our first model (ORIG). The results obtained are: ORIG Model: 41 % AN (acrylonitrile) concerted, 82 % total possible AN; REV Model: 43 % AN concerted, 59 % total possible AN; experimental: 42 % AN concerted, 62 % total possible AN using both the M1 + M2 phases. Comparing the original (Grasselli et al., Top Catal 23:5, 2003) [2] and current (Li et al., Top Catal 54:614, 2011) [3] elemental distributions at the active centers of M1 and the ORIG and REV ammoxidation reaction pathways (from the derived models), it is readily apparent that higher concentrations of V5+ at the active centers lead to undesirable overoxidation of propane and thus lower AN selectivity. Therefore, decreasing the surface concentration of vanadium in M1 (to favor more site isolated V5+ sites) should be beneficial and lead to better AN selectivities and yields. Additionally, selective doping or selective isomorphous substitution of M1 (and/or M2) should also be useful approaches towards improved AN yields. 相似文献
Screen-printed glucose, ethanol and fructose biosensors, coupled with portable instrumentation, and their application to monitor micro-alcoholic fermentations (micro-ALFs) in red wine is described. For the fabrication of glucose and ethanol biosensors, graphite screen-printed sensors modified with Prussian Blue were coupled with oxidase enzymes while for the fructose biosensor, a bare screen-printed sensor was coated with fructose dehydrogenase and phenazine methansulphate was used as electrochemical mediator. The working range, reproducibility of probe fabrication and biosensor stability were all evaluated. After a recovery study, performed analysing fortified must-wine samples, the biosensors were employed to monitor micro-ALFs induced by the inoculation of two different strains of Saccharomyces cerevisiae. During the red micro-ALFs, samples of must-wine were collected and analysed by use of both biosensors and spectrophotometric kits. The data obtained demonstrated that a biosensor-based system could represent a useful tool to assist winemakers during wine production. 相似文献
BACKGROUND & AIMS: To explain the greater hepatoprotective effect of tauroursodeoxycholic acid vs. ursodeoxycholic acid, the absorption, hepatic enrichment, and biotransformation of these bile acids (250 mg/day) were compared in rats. METHODS: Bile acids were determined in intestinal contents, feces, urine, plasma, and liver by gas chromatography-mass spectrometry. RESULTS: The concentration of ursodeoxycholate in the liver of animals administered tauroursodeoxycholic acid (175 +/- 29 nmol/g) was greater (P < 0.05) than in animals administered ursodeoxycholic acid (79 +/- 19 nmol/g). Hepatic lithocholate was substantially higher after ursodeoxycholic acid administration (21 +/- 10 nmol/g) than after tauroursodeoxycholic acid administration (12 +/- 1 nmol/g). A concomitant reduction in the proportion of hydrophobic bile acids occurred that was greatest during tauroursodeoxycholic acid administration. In the intestinal tract, the mass of ursodeoxycholate and its specific metabolites was greater in rats administered tauroursodeoxycholic acid (27.2 mg) than those administered ursodeoxycholic acid (13.2 mg). In feces, the proportion of lithocholate was 21.9% +/- 4.9% and 5.4% +/- 4.0% after ursodeoxycholic acid and tauroursodeoxycholic acid administration, respectively. CONCLUSIONS: Compared with ursodeoxycholic acid, tauroursodeoxycholic acid induces a greater decrease in the percent composition of more hydrophobic bile acids within the pool, limits lithocholate formation, and increases hepatic ursodeoxycholate concentration. These differences are explained by increased hepatic extraction and reduced intestinal biotransformation and not by enhanced absorption of the amidated species. 相似文献
Bronchial asthma is characterized by eosinophil infiltration and tissue remodeling. Matrix metalloproteinases (MMPs) are thought to play critical roles by degradating interstitial matrices in a wide range of lung diseases associated with reorganization of the airway architecture. To investigate whether MMPs are involved in the pathologic processes of bronchial asthma, we examined MMP expression in asthmatic subjects. In situ hybridization revealed abundant expression of MMP-9 (gelatinase B) mRNA in biopsy specimens from asthmatic subjects (n = 5), with an average positive cell distribution of 117.8 +/- 41.1 (mean +/- SEM)/mm2. In contrast, sparse expression of the mRNA (10.8 +/- 4.8 /mm2) was observed in specimens from normal subjects (n = 4). The vast majority of cells expressing the mRNA were eosinophils in asthmatic tissues (92.2 +/- 1.2%). MMP-9 protein, which was confined to the submucosal cells in the normal subjects, was not abundantly expressed in inflammatory cells, but there was positive reactivity for MMP-9 protein in the extracellular matrix. Immunoelectron microscopic analysis showed sparse immunolocalization of MMP-9 in the perinuclear spaces of eosinophils, but not in the granules. These findings suggest the overexpression of MMP-9 by eosinophils in bronchial tissues of asthmatic individuals, and the participation of MMPs in the pathologic changes in asthmatic airways. 相似文献
Iodocyclization of ethynyl methyl sulfides gives 3‐iodo‐2‐thiomethyl heterocycles, setting up the synthesis of thieno‐fused systems through a subsequent iteration of alkyne coupling and iodocylization. This approach can also be exploited in the synthesis of polyfused thiophenes. In developing this protocol it was necessary to address issues associated with unfavourable electronic bias and redox sensitivity in some substrates. The manner in which these have been addressed should prove useful elsewhere in iodocyclization chemisty.