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1.
A 63-year-old man developed paraparesis and signs of meningeal irritation 4 days after a fall which caused a minor contusion of the cervical spine. Magnetic resonance imaging (MRI) revealed an extensive spinal subdural hematoma. The usefulness of MRI for diagnosis and successful conservative treatment is discussed. 相似文献
2.
Conducted 2 studies to examine negative social reactions from the perspective of rejecting peers. The purpose of Study 1 was to test an attributional model of negative peer reactions in which perceptions of responsibility and specific emotions mediate between deviant peer characteristics and negative social responses. The more children perceived atypical classmates to be responsible for their idiosyncrasies, the more anger and less sympathy they reported. Anger increased rejection and decreased social support, whereas sympathy facilitated social support. In Study 2, the effects of responsibility perceptions and affective reactions (annoyance) on social responses were tested with an experimental design. Perceived responsibility influenced liking and support, whereas annoyance affected sympathy, support, and rejection. The results are discussed with respect to intervention programs that would improve children's social acceptance. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
Lifetime of minority carriers has been widely identified to be the key material parameter determining the conversion efficiency of pn-junction silicon solar cells. Impurities and defects in the silicon crystal lattice reduce the charge carrier lifetime and thus limit the performance of the solar cells. Removal of impurities by silicon material purification is often contradictory with low cost production of photovoltaic devices. In this paper, we present experimental results of an efficient gettering technique which can be applied to low cost processing of multicrystalline silicon solar cells without any additional process steps or compromises with optimal device design parameters. This technique is based on well-known phosphorous gettering. We have discovered that if the silicon wafers are kept in the furnace after the emitter diffusion at the 700°C, significant improvement in the lifetime will take place. At this temperature the properties of the pn-junction remain unaffected meanwhile many lifetime killers are still mobile. The time needed for this temperature program can be easily modified in order to respond to the material quality variations in substrates originating from different parts of multicrystalline ingot. Better control of lifetime can lead to higher degree of starting material utilization. 相似文献
4.
T Juvonen DJ Weisz D Wolfe N Zhang CA Bodian JN McCullough CK Mezrow RB Griepp 《Canadian Metallurgical Quarterly》1998,115(5):1142-1159
OBJECTIVE: We assessed the impact on histologic and behavioral outcome of an interval of retrograde cerebral perfusion after arterial embolization, comparing retrograde cerebral perfusion with and without inferior vena caval occlusion with continued antegrade perfusion. METHODS: Sixty Yorkshire pigs (27 to 30 kg) were randomly assigned to the following groups: antegrade cerebral perfusion control; antegrade cerebral perfusion after embolization; retrograde cerebral perfusion control; retrograde cerebral perfusion after embolization; retrograde cerebral perfusion with inferior vena cava occlusion, retrograde cerebral perfusion with inferior vena cava occlusion control, and retrograde cerebral perfusion with inferior vena cava occlusion after embolization. After cooling to 20 degrees C, a bolus of 200 mg of polystyrene microspheres 250 to 750 (microm diameter (or saline solution) was injected into the isolated aortic arch. After 5 minutes of antegrade cerebral perfusion, 25 minutes of antegrade cerebral perfusion, retrograde cerebral perfusion, or retrograde cerebral perfusion with inferior vena cava occlusion was instituted. After the operation, all animals underwent daily assessment of neurologic status until the time of death on day 7. RESULTS: Aortic arch return, cerebral vascular resistance, and oxygen extraction data during retrograde cerebral perfusion showed differences, suggesting that more effective flow occurs during retrograde cerebral perfusion with inferior vena cava occlusion, which also resulted in more pronounced fluid sequestration. Microsphere recovery from the brain revealed significantly fewer emboli after retrograde cerebral perfusion with inferior vena cava occlusion. Behavioral scores showed full recovery in all but one control animal (after retrograde cerebral perfusion with inferior vena cava occlusion) by day 7 but were considerably lower after embolization, with no significant differences between groups. The extent of histopathologic injury was not significantly different among embolized groups. Although no histopathologic lesions were present in either the antegrade cerebral perfusion control group or the retrograde cerebral perfusion control group, mild significant ischemic damage occurred after retrograde cerebral perfusion with inferior vena cava occlusion even in control animals. CONCLUSIONS: Although effective washout of particulate emboli from the brain can be achieved with retrograde cerebral perfusion with inferior vena cava occlusion, no advantage of retrograde cerebral perfusion with inferior vena cava occlusion after embolization is seen from behavioral scores, electroencephalographic recovery, or histopathologic examination; retrograde cerebral perfusion with inferior vena cava occlusion results in greater fluid sequestration and mild histopathologic injury even in control animals. Retrograde cerebral perfusion with inferior vena cava occlusion shows clear promise in the management of embolization, but further refinements must be sought to address its still worrisome potential for harm. 相似文献
5.
R Jantunen E Juvonen E Ikkala K Oksanen P Anttila P Hormila SE Jansson R Kekom?ki T Ruutu 《Canadian Metallurgical Quarterly》1998,77(3):101-106
Antipsychotic drugs are effective in psychoses, whatever the aetiology of the disorder. The positive symptoms tend to respond more readily. The need for developing new drugs arises from the refractoriness of the negative symptoms, the 10-25% of the patients that are treatment-resistant and the problems of short-, and long-term extrapyramidal side-effects. Thus far, five drugs differing from the classical antipsychotics have been licensed for use: clozapine, olanzepine, risperidone, sertindole and sulpiride, and in at least some European countries quetiapine is now in the final phase of clinical research. This review starts with a brief introduction to symptomatology, is limited to the registered drugs and addresses differences with the classical drugs in pharmacology, pharmacokinetics, clinical aspects and side-effects. Clozapine, risperidone and sulpiride can be considered for clinical use in refractory patients, and these three together with olanzapine and sertindole are candidates when extrapyramidal side-effects cause a clinical problem. 相似文献
6.
J. G. F. Coutinho M. P. T. Juvonen J. L. Wang B. L. Lo W. Luk O. Mencer G. Z. Yang 《The Journal of VLSI Signal Processing》2007,47(1):33-45
Posture analysis is an active research area in computer vision for applications such as home care and security monitoring.
This paper describes the design of a system for posture analysis with hardware acceleration, addressing the following four
aspects: (a) a design workflow for posture analysis based on radial shape and projection histogram representations; (b) the
implementation of different architectures based on a high-level hardware design approach with support for automating transformations
to improve parallelism and resource optimisation; (c) accuracy evaluation of the proposed posture analysis system, and (d)
performance evaluation for the derived designs. One of the designs, which targets a Xilinx XC2V6000 FPGA at 90.2 MHz, is able
to perform posture analysis at a rate of 1,164 frames per second with a frame size of 320 by 240 pixels. It represents 3.5
times speedup over optimised software running on a 2.4 GHz AMD Athlon 64 3700+ computer. The frame rate is well above that
of real-time video, which enables the sharing of the FPGA among multiple video sources.
相似文献
J. G. F. CoutinhoEmail: |
7.
Direct synthesis of dimethyl carbonate with supercritical carbon dioxide: Characterization of a key organotin oxide intermediate 总被引:2,自引:0,他引:2
Danielle Ballivet-Tkatchenko Stphane Chambrey Riitta Keiski Rosane Ligabue Laurent Plasseraud Philippe Richard Helka Turunen 《Catalysis Today》2006,115(1-4):80-87
The direct synthesis of dimethyl carbonate (DMC) using carbon dioxide as solvent and reagent for its fixation to methanol was explored with di-n-butyldimethoxystannane in order to get insight into the reaction mechanism for activity improvement. Catalytic runs including recycling experiments allowed isolation and characterization by NMR, IR, and single-crystal X-ray diffraction of a new tin complex containing 10 tin atoms. This compound could be prepared independently and is considered as a resting species. The yield of DMC is highest under 20 MPa pressure that fits with a monophasic supercritical medium in agreement with fluid phase equilibria calculations. In line, preliminary kinetics and initial rate determination show a positive order in carbon dioxide and a first-order dependence on the stannane. The initial rates were lower with the deca-tin complex than with the stannane precursor, but the turnover numbers (TONs) were higher. Water, the co-product of the reaction, was found to reversibly poison the active centers. Its in situ trapping had a beneficial effect. This study provides new mechanistic clues as to the reactive species and DMC formation. Further kinetics work is in progress to determine the rate-limiting step(s) at the initial stage of the reaction for more active catalyst design. 相似文献
8.
Keogh Barbara K.; Juvonen Jaana; Bernheimer Lucinda P. 《Canadian Metallurgical Quarterly》1989,1(3):224
The purposes of this study were to test the replicability of the factor structure of the Health Resources Inventory (HRI; E. L. Gesten [see PA, Vol 57:7209]) for teachers, to describe the factor organization of the HRI when used with parents, and to assess the strength of agreement between parents' and teachers' views of children's competence. Parents' ratings were available for 269 children (ages 4 to 12 years), and teachers' ratings were gathered for a subset of 102. Analysis of teachers' responses confirmed a 5-factor structure of the HRI. The factor structure for mothers closely mirrored that of teachers. The similarity of factor structure argues for the usefulness of the HRI in assessing children's competence at home and school. The relatively modest correlation between mothers' and teachers' ratings suggests possible setting differences in children's behavior and/or variance related to rater source. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Helka Juvonen Maria Smolander Harry Boer Jaakko Pere Johanna Buchert Jouko Peltonen 《应用聚合物科学杂志》2011,119(4):2205-2213
The use of renewable materials as barrier material is currently intensively investigated. Biopolymers such as polysaccharides, lipids, and proteins have been studied as barrier materials. Protein‐based films often possess good gas barrier properties, but because of their hydrophilic nature the gas barrier properties are sensitive to humidity. The improvement of the properties of sodium caseinate barrier films in potential packaging applications was studied by investigating the effects of enzymatic treatment and plasticizer on the film properties. Oxidoreductases Trametes hirsuta laccase (ThL) and Trichoderma reesei tyrosinase (TrTyr) were compared with transglutaminase for crosslinking of the sodium caseinate molecules in the films and coatings. All of the studied enzymes were able to crosslink sodium caseinate. Film solubility tests, protein electrophoresis, contact angle measurements, and atomic force microscopy studies showed that TrTyr treatment results in sodium caseinate films and coatings with better overall properties compared to treatment with ThL. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献