Experimental Investigation on a Cable Structure Equipped with an Electrodynamic Damper and Its Monitoring Strategy through Energy Harvesting.

The vibration of cables in a cable-supported bridge affects its serviceability and safety. Therefore, cable dampers are essential for vibration control, monitoring, and the further maintenance of such bridges. In this study, the vibration control performance of an electrodynamic damper applied to a cable used in a footbridge was experimentally verified considering the major design variables of the damper. The damping performance was analyzed by varying the damping ratio according to the excitation condition and external circuit resistance. The acceleration and displacement at each measurement point and the frequency-domain response decreased. Considering the dominant response conditions of the cables in the bridge, an effective additional attenuation was observed. In addition, the harvesting power considering the measurement frequency and power loss was sufficient to operate a wireless measuring sensor by examining the energy harvesting performance from the cable measurement data of an actual bridge in service. Finally, a stepwise operation strategy for a cable vibration monitoring system was suggested and examined by analyzing the meteorological observation data and the power output according to the wind environment. The results demonstrate the feasibility of using an electrodynamic damper to build an integrated monitoring system capable of simultaneous cable vibration reduction and energy harvesting.

Prevalence and Clinical Features of Drug Reactions With Eosinophilia and Systemic Symptoms Syndrome Caused by Antituberculosis Drugs: A Retrospective Cohort Study.

PURPOSE: Although there have been reported cases of drug reactions with eosinophilia and systemic symptoms (DRESS) syndrome caused by antituberculosis drugs, there has been no research to examine its prevalence. This study assessed the prevalence and clinical characteristics of DRESS syndrome caused by antituberculosis drugs. METHODS: The electronic medical records of a cohort consisting of adult patients diagnosed with tuberculosis between July 2006 and June 2010 were reviewed and retrospectively inspected. We searched the surveillance system for adverse drug reactions and the electronic medical records to identify patients who reported severe cutaneous adverse reactions to antituberculosis drugs. These patients were then re-assessed using a European Registry of Severe Cutaneous Adverse Reactions to Drugs and Collection of Biological Samples (RegiSCAR) scoring system. Clinical characteristics, including the symptoms and latency of DRESS syndrome, the therapeutic dosage and period of steroids, and the final duration of tuberculosis therapy, were examined. RESULTS: Of the 1,253 adult patients with tuberculosis receiving antituberculosis drugs, 15 were identified as potential cases of DRESS syndrome (prevalence of 1.2%). Ethambutol was the most frequently used drug (53.5%), followed by rifampicin (26.7%), pyrazinamide (20.0%), streptomycin (13.3%), and isoniazid (6.7%). The median latency after day 1 of antituberculosis medication was 42 days. The median daily dose of steroids, expressed in prednisone-equivalent units, was 33-mg/day, and the median dosing period was 14 days. The duration of tuberculosis treatment was 76 days longer than the standard treatment period of 180 days. There was a significant difference in the peak eosinophil counts of DRESS syndrome patients according to RegiSCAR scores. Moreover, there was a significant quantitative correlation between the RegiSCAR score and peak eosinophil count. A negative correlation was also found between the RegiSCAR score and latency. CONCLUSIONS: This study confirmed the prevalence of DRESS syndrome in a cohort of adult patients with tuberculosis.

Hot snare polypectomy with or without saline solution/epinephrine lift for the complete resection of small colorectal polyps.

BACKGROUND AND AIMS: The criteria for a standard polypectomy technique for complete removal of small colorectal polyps has not yet been established. This study aimed to compare the complete resection rate of hot snare polypectomy (HSP) with that of EMR for small, sessile, or flat polyps. METHODS: Patients with 5- to 9-mm non-pedunculated colorectal polyps were prospectively randomized to the HSP or EMR group. The presence of residual polyps was assessed by performing histologic assessment of 4-quadrant forceps biopsy specimens taken from the edges of the polypectomy site. The primary outcome was the complete resection rate after HSP or EMR; the secondary outcomes were the proportion of procedure-related adverse events and specimen-loss rate. Sample size was estimated using a superiority trial design. We assumed that the complete resection rate of the EMR group would be at least 8% higher than that of the HSP group. RESULTS: A total of 382 polyps in 269 patients were assessed and randomly assigned to each method using 4 × 4 block randomization. Of these, 353 polyps were finally analyzed based on the pathology results. The mean polyp size was 6.3 ± 1.3 mm. The complete resection rate did not differ between the HSP and EMR groups (88.4% [152/172] vs 92.8% [168/181], respectively; P = .2). The intraprocedural bleeding rate, immediately after polypectomy, was significantly higher in the HSP group than in the EMR group (5.2% vs 0.6%, respectively; P = .009). However, clinically significant bleeding and tissue retrieval failure rates did not differ between the groups. In the multivariate logistic regression analysis, sessile serrated adenoma/polyps or hyperplastic polyps were almost 3 times (odds ratio, 2.824; 95% confidence interval, 1.03-7.75; P = .044) more likely to be incompletely resected compared with other conventional adenomatous polyps. Except for pathology, we found no significant independent predictors for incomplete resection. CONCLUSION: EMR for small non-pedunculated colorectal polyps is not superior to HSP in terms of complete resection or safety. Both methods can be performed according to the endoscopist's preference. (Clinical trial registration number: KCT0001640; cris.nih.go.kr.).

Feasibility Study of the Electromagnetic Damper for Cable Structures Using Real-Time Hybrid Simulation.

Cable structure is a major component of long-span bridges, such as cable-stayed and suspension bridges, and it transfers the main loads of bridges to the pylons. As these cable structures are exposed to continuous external loads, such as vehicle and wind loads, vibration control and continuous monitoring of the cable are required. In this study, an electromagnetic (EM) damper was designed and fabricated for vibration control and monitoring of the cable structure. EM dampers, also called regenerative dampers, consist of permanent magnets and coils. The electromagnetic force due to the relative motion between the coil and the permanent magnet can be used to control the vibration of the structure. The electrical energy can be used as a power source for the monitoring system. The effects of the design parameters of the damper were numerically analyzed and the damper was fabricated. The characteristics of the damper were analyzed with various external load changes. Finally, the vibration-control and energy-harvesting performances of the cable structure were evaluated through a hybrid simulation. The vibration-control and energy-harvesting performances for various loads were analyzed and the applicability to the cable structure of the EM damper was evaluated.

Prevalence and Related Characteristics of Carpal Tunnel Syndrome Among Orchardists in the Gyeongsangnam-do Region.

OBJECTIVE: To determine the prevalence and related characteristics of carpal tunnel syndrome (CTS) in orchardists and to investigate the association between electrodiagnostic severity and physical examinations. METHODS: Between July 2013 and September 2014, 377 subjects (174 men and 203 women) visited the Gyeongsang National University Hospital's Center for Farmer's Safety and Health. All the subjects underwent electrodiagnostic tests and physical examination, including Phalen's test, Tinel's sign, and Durkan's carpal compression test (CCT). The subjects were classified into 2 groups, the normal group and the CTS group, according to electrodiagnostic test results. To determine the related characteristics of CTS, potential variables, including age, sex, drinking, smoking, body mass index, waist circumference, and total work time, were compared between the 2 groups. The association between electrodiagnostic severity and physical examinations was analyzed. RESULTS: CTS was diagnosed in 194 subjects based only on electrodiagnostic test results, corresponding to a prevalence of 51.5%. Among the variables, mean age (p=0.001) and total work time (p=0.007) were significantly correlated with CTS. With respect to the physical examinations, low specificities were observed for Tinel's sign, Phalen's test, and Durkan's CCT (38.4%, 36.1%, and 40.9%, respectively) in the subjects aged ≥65 years. In addition, Phalen's test (p=0.003) and Tinel's sign (p=0.032) in men and Durkan's CCT (p=0.047) in women showed statistically significant differences with increasing CTS severity. The odds ratio was 2.066 for Durkan's CCT in women according to the multivariate logistic regression analysis. CONCLUSION: CTS prevalence among orchardists was high, and Durkan's CCT result was significantly quantitatively correlated with the electrodiagnostic test results. Therefore, Durkan's CCT is another reliable examination method for CTS.

Experimental validation of normalized uniform load surface curvature method for damage localization.

In this study, we experimentally validated the normalized uniform load surface (NULS) curvature method, which has been developed recently to assess damage localization in beam-type structures. The normalization technique allows for the accurate assessment of damage localization with greater sensitivity irrespective of the damage location. In this study, damage to a simply supported beam was numerically and experimentally investigated on the basis of the changes in the NULS curvatures, which were estimated from the modal flexibility matrices obtained from the acceleration responses under an ambient excitation. Two damage scenarios were considered for the single damage case as well as the multiple damages case by reducing the bending stiffness (EI) of the affected element(s). Numerical simulations were performed using MATLAB as a preliminary step. During the validation experiments, a series of tests were performed. It was found that the damage locations could be identified successfully without any false-positive or false-negative detections using the proposed method. For comparison, the damage detection performances were compared with those of two other well-known methods based on the modal flexibility matrix, namely, the uniform load surface (ULS) method and the ULS curvature method. It was confirmed that the proposed method is more effective for investigating the damage locations of simply supported beams than the two conventional methods in terms of sensitivity to damage under measurement noise.

Usefulness of Forward-Viewing Endoscope for Endoscopic Retrograde Cholangiopancreatography in Patients with Billroth II Gastrectomy.

BACKGROUND/AIMS: Patients undergoing Billroth II (B II) gastrectomy are at higher risk of perforation during endoscopic retrograde cholangiopancreatography (ERCP). We assessed the success rate and safety of forward-viewing endoscopic biliary intervention in patients with B II gastrectomy. METHODS: A total of 2,280 ERCP procedures were performed in our institution between October 2008 and June 2011. Of these, forward-viewing endoscopic biliary intervention was performed in 46 patients (38 men and 8 women with B II gastrectomy). Wire-guided selective cannulations of the common bile duct using a standard catheter and guide wire were performed in all patients. RESULTS: The success rate of afferent loop entrance was 42 out of 46 patients (91.3%) and of biliary cannulation after the approach of the papilla was 42 out of 42 patients (100%). No serious complications were encountered, except for one case of small perforation due to endoscopic sphincterotomy site injury. CONCLUSIONS: When a biliary endoscopist has less experience and patient volume is low, ERCP with a forward-viewing endoscope is preferred because of its ease and safety in all patients with prior B II gastrectomies. Also, forward-viewing endoscope can be used to improve the success rate of biliary intervention in B II patients.

[A case of sustained cholestasis caused by acute A viral hepatitis in Dubin-Johnson syndrome].

Dubin-Johnson syndrome is a rare clinical entity. It shows intermittent symptoms such as chronic or intermittent jaundice, abdominal pain, weakness, nausea, vomiting, anorexia and diarrhea. Symptoms are precipitated or aggravated by pregnancy, alcoholism, surgical procedures and intercurrent disease. Chronic idiopathic jaundice is typical of Dubin-Johnson syndrome and its prognosis is good. We describe a case of prolonged cholestasis for more than 10 months caused by acute A viral hepatitis in a patient with Dubin-Johnson syndrome. It is a first report of cholestasis complicated by acute A viral hepatitis in a patient with Dubin-Johnson syndrome.

A common mutation in cholesteryl ester transfer protein gene and plasma HDL cholesterol level before and after hormone replacement therapy in Korean postmenopausal women.

BACKGROUND: Plasma cholesteryl ester transfer protein (CETP) functions to transfer cholesteryl ester from HDL to triglyceride-rich lipoproteins and regulates plasma HDL cholesterol level. A common mutation, the exon 15 A to G substitution at codon 442 (D442G) results in reduced plasma CETP activity and increased plasma HDL cholesterol level. Meanwhile, hormone replacement therapy (HRT) in postmenopausal women increases plasma HDL cholesterol level. METHODS: We investigated the frequency of D442G mutation and its effect on plasma HDL cholesterol level in Korean women. We also examined if the mutation has any effect on an increase in plasma HDL cholesterol level during HRT. RESULTS: Two hundred and twenty eight women aged over 40 years were recruited in this study. Of 228 women, 22 (9.6%) were identified as having the D442G mutation; 21 heterozygotes and 1 homozygote. The subjects with the mutation had higher plasma HDL cholesterol levels than those without the mutation (61.6 +/- 17.3 vs. 55.1 +/- 14.0 mg/dL, p < 0.05). After 12 month HRT, HDL cholesterol increased by 6.4% (3.6 +/- 13.2 mg/dL, p < 0.05) and D442G mutation did not have any significant effect on the change of plasma HDL cholesterol level. CONCLUSION: D442G mutation is common in Korean postmenopausal women and it is associated with increased plasma HDL cholesterol level. HRT for postmenopausal women increased plasma HDL cholesterol level in similar amounts regardless of the presence or absence of D442G mutation.