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The authors propose a novel approach to force and compliance control of multi-degree-of-freedom (DOF) robot manipulators. The acceleration tracing orientation method (ATOM) is applied to both controllers. The control law is described in the Cartesian space; however, the final command is the acceleration in the joint space. The interactive terms in each joint disturb and deteriorate the joint motion. The disturbance observer cancels out the total sum of these terms and enables each joint to trace the acceleration command. As a result, a robust control is possible in the force task. The testing of the proposed system in a three-DOF robot manipulator is discussed  相似文献   
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Oligosaccharides, especially mannose residues, expressed on the cell surface, are thought to be important for virus-induced membrane fusion. We examined the effect of mannose-binding compounds, pradimicin derivative BMY-28,864 (PRM) and concanavalin A (Con A), on cell fusion of human parainfluenza type 2 virus (hPIV2)-infected HeLa cells. Syncytium formation of hPIV2-infected HeLa cells was suppressed in the presence of Con A. On the other hand, PRM enhanced cell fusion of hPIV2-infected HeLa cells. These effects were blocked by addition of mannose-rich mannan. However, PRM shows little effect on virus growth and the expression of viral glycoproteins on the cell surface in hPIV2-infected HeLa cells. Fluorescein-isothiocyanate-labeled pradimicin and Con A bound to both uninfected and hPIV2-infected mononuclear cells, indicating that these compounds have an affinity to several cellular component(s). In contrast to Con A, PRM had little affinity to the viral glycoproteins. It is inferred from these results that the enhancement of hPIV2-induced cell fusion is probably due to the interaction between PRM and cellular component(s).  相似文献   
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Hrs is a 115-kDa double zinc finger protein that is rapidly tyrosine phosphorylated in growth factor-stimulated cells. However, its function remains unknown. Here we show that Hrs is localized to early endosomes. Intracellular localization of endogenous Hrs and exogenously expressed Hrs tagged with the hemagglutinin epitope was examined by immunofluorescence staining using anti-Hrs and anti-hemagglutinin epitope antibodies, respectively. Hrs was detected in vesicular structures and was colocalized with the transferrin receptor, a marker for early endosomes, but only partially with CD63, a marker for late endosomes. A zinc finger domain deletion mutant of Hrs was also colocalized with the transferrin receptor, suggesting that the zinc finger domain is not required for its correct localization. Immunoelectron microscopy showed that Hrs was localized to the cytoplasmic surface of these structures. By subcellular fractionation, Hrs was recovered both in the cytoplasmic and membrane fractions. The membrane-associated Hrs was extracted from the membrane by alkali treatment, suggesting that it is peripherally associated with early endosomes. These results, together with our finding that Hrs is homologous to Vps27p, a protein essential for protein traffic through a prevacuolar compartment in yeast, suggest that Hrs is involved in vesicular transport through early endosomes.  相似文献   
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We inserted human Cu, Zn-superoxide dismutase (hSOD) cDNA into the eukaryotic expression plasmid (pRc/CMV) under the control of the cytomegalovirus promoter. The hSOD expression plasmid (pRc/CMV-SOD) was transfected in L2 cells by mean of lipofection. The intracellular SOD activity in pRc/CMV-SOD transfected cells (CMV-SOD cells) was about twice that in host cells. However the level of extracellular SOD activity was similar in CMV-SOD and host cells. When exposed to xanthine (X)/xanthine oxidase (XO) to generate active oxygen species, significantly more CMV-SOD cells than host cells survived. The production of lipid peroxidation in host cells significantly increased in the presence of X/XO, but that in CMV-SOD cells did not change. Thus, transfection with SOD gene effectively prevented X/XO-induced cytotoxicity. The results indicated that increasing the level of intracellular SOD activity protected cells against extracellular superoxide anion stress.  相似文献   
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The subgrain growth during annealing of cold-worked Al-1% Mn and Al(4N) has been measured in the temperature intervals 300 to 400° C and 100 to 200° C respectively. For Al-1%Mn the subgrain diameter showed a parabolic growth, while for Al the diameter gradually reached a constant value. The microstructural investigations which included in situ annealing in a high voltage electron microscope demonstrated that the operating mechanism for growth in the higher temperature range was collective migration of sub-boundary dislocations. In the lower temperature range extraction of dislocations was found to be the dominating mechanism, i.e. dislocations partly lying in the boundaries are pulled out by the stress field in the subgrain interior. The observed growth rates were consistent with models for these mechanisms presented in two previous papers.  相似文献   
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PURPOSE: To report initial clinical experience with a novel high-precision stereotactic radiotherapy system. METHODS AND MATERIALS: Sixty patients ranging in age from 2 to 82 years received a total of 1426 treatments with the University of Florida frameless stereotactic radiotherapy system. Of the total, 39 (65%) were treated with stereotactic radiotherapy (SRT) alone, and 21 (35%) received SRT as a component of radiotherapy. Pathologic diagnoses included meningiomas (15 patients), low-grade astrocytomas (11 patients), germinomas (9 patients), and craniopharyngiomas (5 patients). The technique was used as means of dose escalation in 11 patients (18%) with aggressive tumors. Treatment reproducibility was measured by comparing bite plate positioning registered by infrared light-emitting diodes (IRLEDs) with the stereotactic radiosurgery reference system, and with measurements from each treatment arc for the 1426 daily treatments (5808 positions). We chose 0.3 mm vector translation error and 0.3 degrees rotation about each axis as the maximum tolerated misalignment before treating each arc. RESULTS: With a mean follow-up of 11 months, 3 patients had recurrence of malignant disease. Acute side effects were minimal. Of 11 patients with low grade astrocytomas, 4 (36%) had cerebral edema and increased enhancement on MR scans in the first year, and 2 required steroids. All had resolution and marked tumor involution on follow-up imaging. Bite plate reproducibility was as follows. Translational errors: anterior-posterior, 0.01 +/- 0.10; lateral, 0.02 +/- 0.07; axial, 0.01 +/- 0.10. Rotational errors (degrees): anterior-posterior, 0.00 +/- 0.03; lateral, 0.00 +/- 0.06; axial, 0.01 +/- 0.04. No patient treatment was delivered beyond the maximum tolerated misalignment. Daily treatment was delivered in approximately 15 min per patient. CONCLUSION: Our initial experience with stereotactic radiotherapy using the infrared camera guidance system was good. Patient selection and treatment strategies are evolving rapidly. Treatment accuracy was the best reported, and the treatment approach was practical.  相似文献   
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Compared the responses to the 16PF of 124 highly successful women psychologists with women in general, college women, and successful academic men to identify personality factors enabling these women to succeed in spite of powerful sex-role expectations to the contrary. In terms of test scores, women psychologists were significantly more intelligent, socially aloof, dominant, serious, adventuresome, sensitive, flexible, imaginative, insightful, unconventional, secure, self-sufficient, and less anxiety-prone than women in general and college girls. Despite similar test profiles of successful academic men and women, the women scored higher on intelligence, radicalism, and super-ego strength, and lower on self-sentiment. Women who published extensively were more exacting and socially aloof than less productive women psychologists. (28 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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