1,279 research outputs found

    GAIT ANALYSIS OF THE NORMAL AND ACL DEFICIENT PATIENTS AFTER LIGAMENT RECONSTRUCTION SURGERY

    Get PDF
    Anterior cruciate ligament (ACL) injury of the knee is common in sports. A serious ACL injury leads to ligament reconstruction surgery. In order to evaluate result of surgery or optimize the rehabilitation process, a knee condition must be objectively identified. The purpose of this study is, therefore, to numerically indicate and classify knee condition of patients via the chaos analysis. Lyapunov exponents (LyEs) were used for the comparison of the normal and the patients

    An Autopsy Case of Postpartum Acute Myocardial Infarction Associated with Postpartum Ergot Alkaloids Administration in Old-Aged Pregnant Women

    Get PDF
    Cases of acute myocardial infarction (AMI) that occur during pregnancy or postpartum are rarely reported. Ergot derivatives are known to induce the spasmodic contraction of coronary arteries. Administration of ergot derivatives can cause AMI, even in normal healthy people. In several reported cases, ergot derivatives triggered severe AMI during the postpartum period. Here, we report the case of a forty-year-old woman who was successfully impregnated by artificial fertilization and died after treatment with ergot derivatives. The autopsy revealed AMI with severe coronary atherosclerosis. This is the first case that reports aggravation of pre-existent severe coronary atherosclerosis after postpartum infusion of ergot derivtives

    >1000-Fold Lifetime Extension of a Nickel Electromechanical Contact Device via Graphene

    Get PDF
    Micro-/nano-electromechanical (M/NEM) switches have received significant attention as promising switching devices for a wide range of applications such as computing, radio frequency communication, and power gating devices. However, M/NEM switches still suffer from unacceptably low reliability because of irreversible degradation at the contacting interfaces, hindering adoption in practical applications and further development. Here, we evaluate and verify graphene as a contact material for reliability-enhanced M/NEM switching devices. Atomic force microscopy experiments and quantum mechanics calculations reveal that energy-efficient mechanical contact–separation characteristics are achieved when a few layers of graphene are used as a contact material on a nickel surface, reducing the energy dissipation by 96.6% relative to that of a bare nickel surface. Importantly, graphene displays almost elastic contact–separation, indicating that little atomic-scale wear, including plastic deformation, fracture, and atomic attrition, is generated. We also develop a feasible fabrication method to demonstrate a MEM switch, which has high-quality graphene as the contact material, and verify that the devices with graphene show mechanically stable and elastic-like contact properties, consistent with our nanoscale contact experiment. The graphene coating extends the switch lifetime >103 times under hot switching conditions

    Reproductive and Hormonal Factors Associated with Fatty or Dense Breast Patterns among Korean Women

    Get PDF
    PURPOSE: Dense breasts have been suggested as a risk factor for breast cancer, but controversy still remains. This study evaluates the association of reproductive and hormonal factors with dense breasts among Korean women. MATERIALS AND METHODS: Using a cross-sectional design, 516 women were recruited and classified for breast density patterns as being either fatty or dense, using the Breast Imaging Reporting and Data System (BI-RADS) of the American College of Radiology. Univariate and multivariate logistic regression models were used for statistical analysis. RESULTS: In univariate logistic regression, older age, higher body mass index, older age at menarche, and oral contraceptive use were associated with more fatty breasts. On the contrary, longer duration of education, alcohol consumption, lower parity, menopause and use of hormone replacement therapy were associated with dense breasts. After adjustment, age and body mass index were inversely associated with breast density (p-value for trend <0.01, respectively), whereas nulliparous and premenopausal status were positively associated. Compared to women who had ≥2 children, nulliparous women had an 11.8-fold increase of dense breasts (p-value for trend <0.01). Compared to postmenopausal women, premenopausal women had 2.4-fold increase of dense breasts (odds ratio, 2.42; 95% confidence interval, 1.36 to 4.32). CONCLUSION: Young age, lower body mass index, lower parity, and premenopausal status were significantly associated with dense breasts in Koreaope

    Insulin Level, RBC Na+ Transport and Blood Pressure in Cushing's Syndrome

    Get PDF
    To test the hypothesis that hyperinsulinemia and / or abnormalities of RBC Na+ transport are concerned in the pathogenesis of hypertension in Cushing's syndrome, we 'investigated the relationship between insulin level, RBC Na + transport and blood pressure in patients with Cushing's syndrome which is frequently associated with hyperinsulinemia, abnormalities of RBC Na + transport and hypertension. Both systolic and diastolic pressure were significantly higher in Cushing's syndrome than in normal subjects. Fasting serum insulin level was higher and both serum glucose and insulin responses after a 75g glucose load were significantly increased in patients with Cushing's syndrome as compared with normal subjects. Both RBC Na+ concentration and passive Na + permeability were significantly lower but Vmax of Na +, K+-pump was significantly higher in patients with Cushing's syndrome than in normal subjects, while Vmaxs of Na+-K+ cotransport and Na+-Li + countertransport were similar in the two groups. In multiple stepwise regression analysis for patients with Cushing's syndrome, fasting serum insulin level was directly correlated with both systolic and diastolic pressures (r=O. 52, p=O. 01; r=O. 51, p=O. 02, respectively). On the other hand,RBC Na + transport parameters showed little correlation with either systolic or diastolic pressures. These results suggest that hyperinsulinemia may contribute to the hypertension in Cushing's syndrome, but that the abnormalities of RBC Na + transport seen in Cushing's syndrome are not causally related to hypertension

    A Case of Primary Ovarian Lymphoma Presenting as a Rectal Submucosal Tumor

    Get PDF
    Primary ovarian lymphoma is a rare malignancy whose symptoms or signs are usually nonspecific. In this article, we report a very rare case initially presenting as a rectal submucosal-tumor-like lesion with a defecation disturbance caused by primary ovarian lymphoma with bilateral involvement. A 42-year-old woman visited chungnam national university hospital complaining of persistent defecation disturbance for 6 months. Colonoscopy demonstrated compression of the rectum by an extrinsic mass mimicking a rectal submucosal tumor. Magnetic resonance imaging detected bilateral ovarian tumors, 9.3 cm and 5.4 cm each in diameter, compressing the rectum without enlarged lymph nodes. The diagnosis was established following a bilateral adnexectomy and histological studies of the excised tissue. The tumor was classified as a diffuse large B-cell lymphoma. The patient was prescribed six cycles of standard CHOP (cyclophosphamide, hydroxydaunorubicin, vincristine, prednisolone) regimen and is presently on treatment

    The usefulness of noninvasive liver stiffness assessment using shear-wave elastography for predicting liver fibrosis in children

    Get PDF
    Background Pediatric patients with liver disease require noninvasive monitoring to evaluate the risk of fibrosis progression. This study aimed to identify the significant factors affecting liver stiffness values using two-dimensional shear-wave elastography (2D-SWE), and determine whether liver stiffness can predict the fibrosis stage of various childhood liver diseases. Methods This study included 30 children (22 boys and 8 girls; mean age, 5.1 ± 6.1 years; range, 7 days–17.9 years) who had undergone biochemical evaluation, 2D-SWE examination, histopathologic analysis of fibrosis grade (F0 to F3), assessment of necroinflammatory activity, and steatosis grading between August 2016 and March 2020. The liver stiffness from 2D-SWE was compared between fibrosis stages using Kruskal–Wallis analysis. Factors that significantly affected liver stiffness were evaluated using univariate and multivariate linear regression analyses. The diagnostic performance was determined from the area under the receiver operating curve (AUC) values of 2D-SWE liver stiffness. Results Liver stiffness at the F0-1, F2, and F3 stages were 7.9, 13.2, and 21.7 kPa, respectively (P < 0.001). Both fibrosis stage and necroinflammatory grade were significantly associated with liver stiffness (P < 0.001 and P = 0.021, respectively). However, in patients with alanine aminotransferase (ALT) levels below 200 IU/L, the only factor affecting liver stiffness was fibrosis stage (P = 0.030). The liver stiffness value could distinguish significant fibrosis (≥ F2) with an AUC of 0.950 (cutoff value, 11.3 kPa) and severe fibrosis (F3 stage) with an AUC of 0.924 (cutoff value, 18.1 kPa). The 2D-SWE values for differentiating significant fibrosis were 10.5 kPa (≥ F2) and 18.1 kPa (F3) in patients with ALT levels below 200 IU/L. Conclusion The liver stiffness values on 2D-SWE can be affected by both fibrosis and necroinflammatory grade and can provide excellent diagnostic performance in evaluating the fibrosis stage in various pediatric liver diseases. However, clinicians should be mindful of potential confounders, such as necroinflammatory activity or transaminase level, when performing 2D-SWE measurements for liver fibrosis staging.This work was supported by grant no 04–2020-0760 from the SNUH Research Fund and by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2020R1C1C1008716). The funder had no involvement or infuence whatsoever in the study design at any stage, collec‑tion of the data or its analysis and interpretation, writing and preparation of the manuscript, or its submission for publication
    corecore