747 research outputs found

    Development of an Operating Robot System for Die and Mold Polishing

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    This paper proposes an operating robot system that assists polishing tasks in die and mold manufacturing. The proposed system consists of an industrial robot and a joystick. Theoperator manipulates the joystick and remotely moves a tool attached at the hand of the robot. A three-DOF motor-driven joystick was developed, and a force-reflecting bilateralcontroller was constructed in order to realize interactive manual operation. In addition to manual operation, the system can control the contact force of the tool automatically by the force feedback. The operator can use two control modes according to the task. The combination of the manual control and the automatic control enables effective and flexible polishing tasks of objects having complex shape. The developed system was applied to simple polishing tasks. Experimental results show that the tool can be manipulated remotely as if we were handling it directly. Moreover, the results suggest that the system increases the efficiency of polishing tasks remarkably

    Lipoprotein(a) is a predictor for cardiovascular mortality of hemodialysis patients

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    Lipoprotein(a) is a predictor for cardiovascular mortality of hemodialysis patients.BackgroundAlthough hemodialysis (HD) patients have been associated with elevations in serum lipoprotein(a) [Lp(a)] levels, relatively little has been published on the link between Lp(a) and the risk for atherosclerotic cardiovascular death in HD patients.MethodsLipoprotein(a) was measured in 390 HD patients. The relationship between Lp(a) and mortality (overall and cardiovascular) was determined during 28 months of prospective follow-up.ResultsHemodialysis patients demonstrated Lp(a) concentrations that were approximately two times as high as that of healthy controls (median, 16 vs. 8 mg/dl, P < 0.001; mean, 22.9 vs. 12.1 mg/dl, P < 0.01). Lp(a) showed a significant correlation between albumin, total cholesterol, low-density lipoprotein cholesterol, and C-reactive protein. The high-Lp(a) group [Lp(a) ≥ 30 mg/dl] showed significantly higher mortality than the low-Lp(a) group [Lp(a) < 30 mg/dl] in a Kaplan–Meier survival analysis (P < 0.05). Multiple logistic regression analysis demonstrated albumin, age, and diabetic state as significant risk factors for overall death. However, if confined to atherosclerotic cardiovascular death, Lp(a) (P < 0.01), age, and diabetic state were the only independent contributors.ConclusionsLp(a) is an independent risk factor for atherosclerotic cardiovascular death in Japanese patients receiving chronic dialysis therapy

    Hemodynamic Changes in the Brachial Artery Induced by Acupuncture Stimulation on the Lower Limbs: A Single-Blind Randomized Controlled Trial

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    Acupuncture is commonly performed at acupoints. No comparisons of quantitative physiological alterations in the brachial artery (BA) induced by the stimulation of different acupoints in the lower limbs have been performed in humans. Therefore, we investigated changes in blood flow volume (BFV) in the BA as an indicator of the physiological effects induced by stimulation at 3 points. Seventy-five healthy participants aged 33 ± 9 years (mean ± SD) were enrolled and randomly assigned to 3 groups; they received stimulation at 3 different points located on the lower limbs: ST36, LR3, and a non-acupoint. Stimulation was performed bilaterally with manual rotation of the needles. Using ultrasonography, BFV was measured continuously from rest to 180 seconds after stimulation. LR3 stimulation significantly increased BFV compared to that before needle insertion. Meanwhile, stimulation at ST36 and the non-acupoint significantly decreased BFV compared to that before needle insertion. Stimulation at LR3 elicited a significant increase in BFV compared to that at ST36 and the non-acupoint. The results suggest that the stimulation of different points on the lower limbs causes distinct physiological effects on BFV in the BA

    Location of phosphorylation site and DNA-binding site of a positive regulator, OmpR, involved in activation of the osmoregulatory genes of Escherichia coli

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    AbstractThe OmpR protein of Escherichia coli is a positive regulator involved in activation of the ompF and ompC genes which encode the major outer membrane proteins OmpF and OmpC, respectively. By employing recombinant DNA techniques, we isolated the N- and C-terminal halves of the OmpR molecule. From the results of biochemical analyses of these fragments, it was concluded that the N-terminal portion contains a site involved in phosphorylation by an OmpR-specific protein kinase EnvZ, whereas the C-terminal part possesses a DNA-binding site for the ompC and ompF promoters

    Transfer of rice mitochondrial ribosomal protein L6 gene to the nucleus: acquisition of the 5'-untranslated region via a transposable element

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    <p>Abstract</p> <p>Background</p> <p>The mitochondria of contemporary organisms contain fewer genes than the ancestral bacteria are predicted to have contained. Because most of the mitochondrial proteins are encoded in the nucleus, the genes would have been transferred from the mitochondrion to the nucleus at some stage of evolution and they must have acquired cis-regulatory elements compatible with eukaryotic gene expression. However, most of such processes remain unknown.</p> <p>Results</p> <p>The ribosomal protein L6 gene (<it>rpl6</it>) has been lost in presently-known angiosperm mitochondrial genomes. We found that each of the two rice <it>rpl6 </it>genes (<it>OsRpl6-1 </it>and <it>OsRpl6-2</it>) has an intron in an identical position within the 5'-untranslated region (UTR), which suggests a duplication of the <it>rpl6 </it>gene after its transfer to the nucleus. Each of the predicted RPL6 proteins lacks an N-terminal extension as a mitochondrial targeting signal. Transient assays using green fluorescent protein indicated that their mature N-terminal coding regions contain the mitochondrial targeting information. Reverse transcription-PCR analysis showed that <it>OsRpl6-2 </it>expresses considerably fewer transcripts than <it>OsRpl6-1</it>. This might be the result of differences in promoter regions because the 5'-noncoding regions of the two <it>rpl6 </it>genes differ at a point close to the center of the intron. There are several sequences homologous to the region around the 5'-UTR of <it>OsRpl6-1 </it>in the rice genome. These sequences have characteristics similar to those of the transposable elements (TE) belonging to the <it>PIF</it>/Harbinger superfamily.</p> <p>Conclusion</p> <p>The above evidences suggest a novel mechanism in which the 5'-UTR of the transferred mitochondrial gene was acquired via a TE. Since the 5'-UTRs and introns within the 5'-UTRs often contain transcriptional and posttranscriptional cis-elements, the transferred rice mitochondrial <it>rpl6 </it>gene may have acquired its cis-element from a TE.</p
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