27 research outputs found

    Residual stress measurement of {112}-oriented CrN layers in CrN/Cr multilayer films

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    In this work, the authors propose and verify a method of measuring the residual stress of {112}-oriented chromium nitride (CrN) layers in CrN/Cr multilayer thin films. The CrN layers of a CrN/Cr multilayer film deposited on a Ti6Al4V substrate by arc ion plating form both a randomly oriented mixed crystal structure and a {112}-oriented structure. Therefore, accurate stress measurement of the CrN layers cannot be performed by applying the sin2ψ x-ray method assuming an isotropic homogeneous material. To overcome this obstacle, the proposed method to measure the residual stress uses four CrN-422 diffractions: at ψ = 0°, 33.56°, 48.19°, and 60.00°. Next, the authors vary the density of Cr droplets on the film surface to evaluate how it affects the residual stress in the CrN/Cr multilayer film. The results indicate that the Cr layer has a residual compressive stress of −350 to −530 MPa and that the two CrN layers have a very large residual compressive stress of −3.5 to −8.2 GPa. In addition, both residual compressive stresses decrease with increasing droplet density

    Measurement of the residual stress in CrN coatings deposited on an Al alloy substrate

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    Chromium nitride (CrN) coatings were deposited on Al alloy substrates using the arc ion plating method with different bias voltages and different thicknesses. The residual stresses of these samples were measured via x-ray diffraction using the sin2 ψ method because the CrN crystals in the coatings were nonoriented. The stress gradient across the CrN coating was calculated from the curved 2θ-sin2 ψ diagram. In the case of CrN coatings deposited at low bias voltage, the compressive residual stress that formed at the substrate interface was larger than the stress at the surface of the CrN coating. Conversely, in the case of CrN coatings deposited at high bias voltage, the compressive residual stress on the surface of the CrN coating was larger than the stress on the interface with the substrate. In CrN coatings deposited at high bias voltage, very large compressive residual stress on the CrN coating surface decreased with increasing coating thickness

    Attitude of young psychiatrists toward coercive measures in psychiatry: a case vignette study in Japan

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    <p>Abstract</p> <p>Background</p> <p>Every psychiatrist must pay careful attention to avoid violating human rights when initiating coercive treatments such as seclusion and restraint. However, these interventions are indispensable in clinical psychiatry, and they are often used as strategies to treat agitated patients. In this study, we investigated young psychiatrists' attitudes toward psychiatric coercive measures.</p> <p>Methods</p> <p>A total of 183 young psychiatrists participated as subjects in our study. A questionnaire with a case vignette describing a patient with acute psychosis was sent to the study subjects via the Internet or by mail. This questionnaire included scoring the necessity for hospitalization, and the likelihood of prescribing seclusion and/or restraint, on a 9-point Likert scale (with 9 indicating strong agreement).</p> <p>Results</p> <p>There was general agreement among the study subjects that the case should be admitted to a hospital (8.91 ± 0.3) and secluded (8.43 ± 1.0). The estimated length of hospitalization was 13.53 ± 6.4 weeks. Regarding the likelihood of prescribing restraint, results showed great diversity (5.14 ± 2.5 on 9-point scale); psychiatrists working at general hospitals scored significantly higher (6.25 ± 2.5) than those working at university hospitals (5.02 ± 2.3) or psychiatric hospitals (4.15 ± 2.6). A two-group comparison of the length of inpatient care revealed a significant difference between those psychiatrists who scored 1-3 (n = 55, 14.22 ± 7.4 wks) and those who scored 7-9 (n = 62, 12.22 ± 4.0) regarding the need to use restraint.</p> <p>Conclusion</p> <p>Our results may reflect the current dilemma in Japanese psychiatry wherein psychiatrists must initiate coercive measures to shorten hospitalization stays. This study prompted its subject psychiatrists to consider coercive psychiatric treatments.</p

    Cellular HIV-1 DNA levels in patients receiving antiretroviral therapy strongly correlate with therapy initiation timing but not with therapy duration

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    <p>Abstract</p> <p>Background</p> <p>Viral reservoir size refers to cellular human immunodeficiency virus-1 (HIV-1) DNA levels in CD4<sup>+ </sup>T lymphocytes of peripheral blood obtained from patients with plasma HIV-1-RNA levels (viral load, VL) maintained below the detection limit by antiretroviral therapy (ART). We measured HIV-1 DNA levels in CD4<sup>+ </sup>lymphocytes in such patients to investigate their clinical significance.</p> <p>Methods</p> <p>CD4<sup>+ </sup>T lymphocytes were isolated from the peripheral blood of 61 patients with a VL maintained at less than 50 copies/ml for at least 4 months by ART and total DNA was purified. HIV-1 DNA was quantified by nested PCR to calculate the copy number per 1 million CD4<sup>+ </sup>lymphocytes (relative amount) and the copy number in 1 ml of blood (absolute amount). For statistical analysis, the Spearman rank or Wilcoxon signed-rank test was used, with a significance level of 5%.</p> <p>Results</p> <p>CD4 cell counts at the time of sampling negatively correlated with the relative amount of HIV-1 DNA (median = 33 copies/million CD4<sup>+ </sup>lymphocytes; interquartile range [IQR] = 7-123 copies/million CD4<sup>+ </sup>lymphocytes), but were not correlated with the absolute amounts (median = 17 copies/ml; IQR = 5-67 copies/ml). Both absolute and relative amounts of HIV-1 DNA were significantly lower in six patients in whom ART was initiated before positive seroconversion than in 55 patients in whom ART was initiated in the chronic phase, as shown by Western blotting. CD4 cell counts before ART introduction were also negatively correlated with both the relative and absolute amounts of HIV-1 DNA. Only the relative amounts of HIV-1 DNA negatively correlated with the duration of VL maintenance below the detection limit, while the absolute amounts were not significantly correlated with this period.</p> <p>Conclusions</p> <p>The amounts of cellular HIV-1 DNA in patients with VLs maintained below the detection limit by the introduction of ART correlated with the timing of ART initiation but not with the duration of ART. In addition, CD4<sup>+ </sup>T lymphocytes, which were newly generated by ART, diluted latently infected cells, indicating that measurements of the relative amounts of cellular HIV-1 DNA might be underestimated.</p

    Suicidal ideation and burnout among psychiatric trainees in Japan

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    AIM: Burnout is a psychological condition that may occur in all workers after being exposed to excessive work-related stresses. We investigated suicidal ideation and burnout among Japanese psychiatric trainees as a part of the Burnout Syndrome Study (BoSS) International.  METHODS: In the Japanese branch, 91 trainees fully completed suicide ideation and behaviour questionnaire (SIBQ) and Maslach Burnout Inventory-General Survey (MBI-GS).  RESULTS: Passive suicidal ideation was reported by 38.5% of Japanese trainees and 22.0% of them had experienced active suicidal ideation. The burnout rate among Japanese subjects was 40.0%. These results were worse compared to the all 1980 trainees who fully completed the main outcome measure in BoSS International, 25.9%, 20.4% and 36.7%, respectively.  CONCLUSIONS: Our results suggest a higher risk of suicide among Japanese residents. Japan has a higher suicide rate than other countries. Early detection of, and appropriate intervention for, suicidal ideation is important in preventing suicide in psychiatry residents

    A novel fully covered metal stent for unresectable malignant distal biliary obstruction: results of a multicenter prospective study

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    Background/Aims Endoscopic self-expandable metal stent (SEMS) placement is currently the standard technique for treating unresectable malignant distal biliary obstructions (MDBO). Therefore, covered SEMS with longer stent patency and fewer migrations are required. This study aimed to assess the clinical performance of a novel, fully covered SEMS for unresectable MDBO. Methods This was a multicenter single-arm prospective study. The primary outcome was a non-obstruction rate at 6 months. The secondary outcomes were overall survival (OS), recurrent biliary obstruction (RBO), time to RBO (TRBO), technical and clinical success, and adverse events. Results A total of 73 patients were enrolled in this study. The non-obstruction rate at 6 months was 61%. The median OS and TRBO were 233 and 216 days, respectively. The technical and clinical success rates were 100% and 97%, respectively. Furthermore, the rate of occurrence of RBO and adverse events was 49% and 21%, respectively. The length of bile duct stenosis (<2.2 cm) was the only significant risk factor for stent migration. Conclusions The non-obstruction rate of a novel fully covered SEMS for MDBO is comparable to that reported earlier but shorter than expected. Short bile duct stenosis is a significant risk factor for stent migration

    Effect of tranexamic acid administration on intraoperative blood loss during peritonectomy: a single-center retrospective observational study

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    Abstract Background The efficacy of tranexamic acid in elective major invasive abdominal surgeries has not yet been established. We investigated the effect of tranexamic acid administration on intraoperative blood loss during peritoneal resection of pseudomucinoma and cancerous peritoneal dissemination. Methods Patients aged ≥ 20 years old who underwent peritoneal resection for pseudomucinoma or cancerous peritoneal dissemination at the Kishiwada Tokushukai Hospital were included in this single-center retrospective observational study. The tranexamic acid group received 1000 mg of tranexamic acid at the start of the operation, while the control group received the same intraoperative management as the tranexamic acid group, except for the tranexamic acid administration. The primary endpoint was intraoperative blood loss, and a multivariate analysis of the contributing factors was performed. Results The median volume of intraoperative blood loss was 1372 [interquartile range, 842 − 1877] mL and 907 [516 − 1537] mL in the control and tranexamic acid groups, respectively (p < 0.01). The total volume of blood transfusion during the operation was 2040 [1480 − 2380] mL and 1560 [1000 − 2120] mL in the control and tranexamic acid groups, respectively (p = 0.02). Postoperative blood test results revealed D-dimer values of 7.5 [4.1 − 10.7] µg/mL and 1.8 [1.0 − 3.3] µg/mL in the control and tranexamic acid groups, respectively (p < 0.01). Multivariate analysis showed that tranexamic acid administration was significantly associated with decreased intraoperative blood loss (p = 0.02). Conclusion Tranexamic acid administration may be useful in reducing intraoperative blood loss and blood transfusion volume during highly-invasive surgeries such as peritoneal resection of pseudomucinoma and cancerous peritoneal dissemination

    Relationship Between Gastric Ulcer and Helicobacter pylori VacA Detected in Gastric Juice Using Bead-ELISA Method

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    Background. VacA is an important pathogenetic factor produced by Helicobacter pylori. VacA has often been detected in supernatants of liquid cultures or lysates of whole bacterial cells. However, no studies have ever tried to assay VacA produced in the human stomach. We applied a very sensitive and simple method, bead-ELISA, to detect VacA in gastric juice. Materials and Methods. Forty-eight H. pylori-positive patients (16 nonulcer dyspepsia, 16 gastric ulcer, and 16 duodenal ulcer) and four H. pylori-negative nonulcer dyspepsia patients had endoscopy performed and gastric juice were aspirated. Polystyrene beads coated with the antibody to VacA, were used in this bead-ELISA method. The nucleotide sequences of vacA in the signal and middle regions were investigated. Results. Of the 48 samples that were positive for H. pylori, 21 [43.8%] were found to be VacA positive in gastric juice. The average and maximum concentrations of detected VacA in gastric juice were 143.2 ± 216.5 and 840 pg/ml, respectively. The average density of VacA from gastric ulcer patients (227.5 ± 276.7 pg/ml) was higher than that found in nonulcer dyspepsia (51.8 ± 39.8 pg/ml) and duodenal ulcer (49.2 ± 21.5 pg/ml) patients. There was no relationship between VacA in gastric juice and vacA genotype. Conclusions. VacA in gastric juice could be directly detected by bead-ELISA. In this study, the diversity of disease outcome was associated with not the quality but the quantity of VacA. Therefore, not only the quality but also the quantity of VacA is important etiological factors in the pathogenesis of mucosal damage
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