264 research outputs found

    Method for determining the power-saved driving motion of manipulators by heuristic algorithms (In case of CP control)

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    This study proposes a method for suppressing the torques of the manipulators, with considering the effect of inertial forces in order to achieve the power-saved drive. The present study generates the trajectories, which here reveal time profiles of positions, velocities and accelerations of the entire path of the output point of manipulators. The trajectories of manipulators are introduced by determining both the initial position and motion curves for the entire path. This study expresses the motion curve as a polynomial and determines its coefficients. The initial pose and unknown coefficients are decided by a heuristic algorithm to achieve power-saved drive. As such problems have non-linearity and multi-peak solutions, it is difficult to find out the optimum one. Thus, this study uses a heuristic algorithm "SHA" to determine the appropriate motions of manipulators, because the heuristic algorithm is, as well known, an effective solution for such complicated problem. This study determines the optimal motions of the PUMA560 comprising spatial 3 degrees-of-freedom by the proposed method, and verifies its availability

    Compensatory Thrombopoietin Production from the Liver and Bone Marrow Stimulates Thrombopoiesis of Living Rat Megakaryocytes in Chronic Renal Failure

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    Background/Aims: Decreased thrombopoiesis has been ascribed a role in the pathogenesis of uremic bleeding in chronic renal failure (CRF). However, serum thrombopoietin (TPO) levels are usually elevated in CRF patients, suggesting increased thrombopoiesis. The aim of this study was to determine the thrombopoietic activity in CRF. Methods: Male Sprague-Dawley rats that underwent 5/6 nephrectomy were used as the model of CRF. Age-matched sham-operated rats were used as controls. Single megakaryocytes were isolated from the rat bone marrow, and their size distribution was examined. Megakaryocyte membrane invaginations were monitored by confocal imaging of di-8-ANEPPS staining, and patch clamp whole-cell recordings of membrane capacitance. TPO gene expression was assessed in various tissues. Results: Circulating platelet counts and the number of large megakaryocytes were increased in the bone marrow of CRF rats. Massive di-8-ANEPPS staining and increased membrane capacitance in large megakaryocytes demonstrated increased membrane invaginations. Unaffected Kv1.3-channel currents per cell surface area demonstrated unaltered channel densities. TPO transcription was decreased in the renal cortex but increased in the liver and bone marrow of CRF rats. Conclusion: Increased thrombopoiesis in CRF was thought to be a reactive mechanism to platelet dysfunction. Increased TPO production from the liver and bone marrow compensated for decreased production from damaged kidneys

    Factors associated with quality of bystander CPR: The presence of multiple rescuers and bystander-initiated CPR without instruction

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    Aims: To identify the factors associated with good-quality bystander cardiopulmonary resuscitation (BCPR). Methods: Data were prospectively collected from 553 out-of-hospital cardiac arrests (OHCAs) managed with BCPR in the absence of emergency medical technicians (EMT) during 2012. The quality of BCPR was evaluated by EMTs at the scene and was assessed according to the standard recommendations for chest compressions, including proper hand positions, rates and depths. Results: Good-quality BCPR was more frequently confirmed in OHCAs that occurred in the central/urban region (56.3% [251/446] vs. 39.3% [42/107], p= 0.0015), had multiple rescuers (31.8% [142/446] vs. 11.2% [12/107], p< 0.0001) and received bystander-initiated BCPR (22.0% [98/446] vs. 5.6% [6/107], p< 0.0001). Good-quality BCPR was less frequently performed by family members (46.9% [209/446] vs. 67.3% [72/107], p= 0.0001), elderly bystanders (13.5% [60/446] vs. 28.0% [30/107], p= 0.0005) and in at-home OHCAs (51.1% [228/446] vs. 72.9% [78/107], p< 0.0001). BCPR duration was significantly longer in the good-quality group (median, 8 vs. 6. min, p= 0.0015). Multiple logistic regression analysis indicated that multiple rescuers (odds ratio. = 2.8, 95% CI 1.5-5.6), bystander-initiated BCPR (2.7, 1.1-7.3), non-elderly bystanders (1.9, 1.1-3.2), occurrence in the central region (2.1, 1.3-3.3) and duration of BCPR (1.1, 1.0-1.1) were associated with good-quality BCPR. Moreover, good-quality BCPR was initiated earlier after recognition/witness of cardiac arrest compared with poor-quality BCPR (3 vs. 4. min, p= 0.0052). The rate of neurologically favourable survival at one year was 2.7 and 0% in the good-quality and poor-quality groups, respectively (p= 0.1357). Conclusions: The presence of multiple rescuers and bystander-initiated CPR are predominantly associated with good-quality BCPR. © 2013 Elsevier Ireland Ltd

    Vasopressin-independent renal urinary concentration: Increased rBSC1 and enhanced countercurrent multiplication

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    Vasopressin-independent renal urinary concentration: Increased rBSC1 and enhanced countercurrent multiplication.BackgroundA close association between the expression of the sodium transporter, rat bumetanide sensitive cotransporter (rBSC), in thick ascending limb of Henle and urinary concentration has been reported. However, direct evidence for this association and the mechanism of rBSC1 expression are still to be elucidated.MethodsBrattleboro (BB) rats weighing approximately 200g were dehydrated by water restriction for 4 hours, which induced around a 5% body weight reduction. Although plasma arginine vasopressin (AVP) was undetectable even after the water restriction, BB rats concentrated urine from 182 ± 23 (mean ± SD) at baseline to 404 ± 65 mOsm/kg · H2O.ResultsUrinary volume was reduced from 5.8 ± 1.8 to 1.4 ± 0.6mL/h. This treatment significantly increased sodium and urea accumulation in the renal medulla and reduced urinary sodium excretion. rBSC1 signals for both mRNA and protein were increased in dehydrated rats, although aquaporin type 2 (AQP2) expression was not enhanced in dehydrated BB rats. Subcutaneous infusion of desmopressin acetate (DDAVP) intensified rBSC1 signals of BB rats more than those in dehydrated condition.ConclusionDehydration increased rBSC1 expression and enhanced countercurrent multiplication even in AVP deficiency. These results supply strong evidence for the association between rBSC1 expression and urinary concentration, and indicate the presence of an AVP-independent mechanism for urine concentration

    Basic life support training for single rescuers efficiently augments their willingness to make early emergency calls with no available help: A cross-over questionnaire survey

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    Background: The aim of this study was to investigate effects of basic life support (BLS) training on willingness of single rescuers to make emergency calls during out-of-hospital cardiac arrests (OHCAs) with no available help from others.Methods: A cross-over questionnaire survey was conducted with two questionnaires. Questionnaires were administered before and after two BLS courses in fire departments. One questionnaire included two scenarios which simulate OHCAs occurring in situations where help from other rescuers is available (Scenario-M) and not available (Scenario-S). The conventional BLS course was designed for multiple rescuers (Course-M), and the other was designed for single rescuers (Course-S).Results: Of 2,312 respondents, 2,218 (95.9%) answered all questions and were included in the analysis. Although both Course-M and Course-S significantly augmented willingness to make early emergency calls not only in Scenario-M but also in Scenario-S, the willingness for Scenario-M after training course was significantly higher in respondents of Course-S than in those of Course-M (odds ratio 1.706, 95% confidential interval 1.301-2.237). Multiple logistic regression analysis for Scenario-M disclosed that post training (adjusted odds ratio 11.6, 95% confidence interval 7.84-18.0), age (0.99, 0.98-0.99), male gender (1.77, 1.39-2.24), prior BLS experience of at least three times (1.46, 1.25-2.59), and time passed since most recent training during 3 years or less (1.80, 1.25-2.59) were independently associated with willingness to make early emergency calls and that type of BLS course was not independently associated with willingness. Therefore, both Course-M and Course-S similarly augmented willingness in Scenario-M. However, in multiple logistic regression analyses for Scenario-S, Course-S was independently associated with willingness to make early emergency calls in Scenario-S (1.26, 1.00-1.57), indicating that Course-S more efficiently augmented willingness. Moreover, post training (2.30, 1.86-2.83) and male gender (1.26, 1.02-1.57) were other independent factors associated with willingness in Scenario-S.Conclusions: BLS courses designed for single rescuers with no help available from others are likely to augment willingness to make early emergency calls more efficiently than conventional BLS courses designed for multiple rescuers. © 2014 Hirose et al

    Reverse pharmacological effect of loop diuretics and altered rBSC1 expression in rats with lithium nephropathy

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    Reverse pharmacological effect of loop diuretics and altered rBSC1 expression in rats with lithium nephropathy.BackgroundRenal urinary concentration is associated with enhanced expression of rBSC1, a rat sodium cotransporter, in the thick ascending limb of Henle. Increased expression of rBSC1 was reported recently in nephrogenic diabetes insipidus induced by lithium chloride (Li nephropathy). However, the pathophysiological implication of altered rBSC1 expression has not yet been investigated.MethodsLi nephropathy was induced in rats by an oral administration of 40 mmol lithium/kg dry food. In rats with reduced urinary osmolality to less than 300 mOsm/kg H2O, we examined the expression of rBSC1 mRNA and protein, plasma arginine vasopressin (AVP) and RNA expression of kidney-specific water channel, aquaporin-2 (AQP2), of collecting ducts. Rats with Li nephropathy were treated with furosemide (3 mg/kg body weight), which blocks the activity of rBSC1, and changes in urine concentration, plasma AVP, medullary accumulation of Li ions, and apical AQP2 expression were determined.ResultsRats with Li nephropathy showed increased rBSC1 RNA and protein expression and reduced AQP2 RNA. In these rats, furosemide, which induces dilution of urine and polyuria in normal rats, resulted in a progressive and significant rise in urine osmolality from 167 ± 11 (mean ± SD) at baseline to 450 ± 45 mOsm/kg H2O at three hours after administration, and significant oliguria. In the same rats, plasma AVP decreased significantly from 5.7 to 3.0 pg/mL. In addition, recovery of apical AQP2 expression was noted in a proportion of epithelial cells of the collecting ducts. Although Li+ in the renal medulla was slightly lower in rats with Li nephropathy treated with furosemide, statistical significance was not achieved.ConclusionsOur results suggest that dehydration or high plasma AVP results in an enhanced rBSC1 expression in Li nephropathy, and that rBSC1 expression is closely associated with the adverse effects of Li ions on collecting duct function
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