A Comparative Study on the Efficacy of Covered Metal Stent and Plastic Stent in Unresectable Malignant Biliary Obstruction

Background/AimsThe placement of self expandable metal stent (SEMS) is one of the palliative therapeutic options for patients with unresectable malignant biliary obstruction. The aim of this study was to compare the effectiveness of a covered SEMS versus the conventional plastic stent.MethodsWe retrospectively evaluated 44 patients with unresectable malignant biliary obstruction who were treated with a covered SEMS (21 patients) or a plastic stent (10 Fr, 23 patients). We analyzed the technical success rate, functional success rate, early complications, late complications, stent patency and survival rate.ResultsThere was one case in the covered SEMS group that had failed technically, but was corrected successfully using lasso. Functional success rates were 90.5% in the covered SEMS group and 91.3% in the plastic stent group. There was no difference in early complications between the two groups. Median patency of the stent was significantly prolonged in patients who had a covered SEMS (233.6 days) compared with those who had a plastic stent (94.6 days) (p=0.006). During the follow-up period, stent occlusion occurred in 11 patients of the covered SEMS group. Mean survival showed no significant difference between the two groups (covered SEMS group, 236.9 days; plastic stent group, 222.3 days; p=0.182).ConclusionsThe patency of the covered SEMS was longer than that of the plastic stent and the lasso of the covered SEMS was available for repositioning of the stent

Inter-arm arterial pressure difference caused by prone position in the thoracic outlet syndrome patient -A case report-

Thoracic outlet syndrome has neurologic symptoms caused by compression of brachial plexus, blood vessel symptoms are caused by compression of the artery or vein. The authors report a case of sudden decrease in blood pressure of the left arm after turning the patient from supine position to prone position. They confirmed that the patient had thoracic outlet syndrome after performing computed tomography

New Era of Air Quality Monitoring from Space: Geostationary Environment Monitoring Spectrometer (GEMS)

GEMS will monitor air quality over Asia at unprecedented spatial and temporal resolution from GEO for the first time, providing column measurements of aerosol, ozone and their precursors (nitrogen dioxide, sulfur dioxide and formaldehyde). Geostationary Environment Monitoring Spectrometer (GEMS) is scheduled for launch in late 2019 - early 2020 to monitor Air Quality (AQ) at an unprecedented spatial and temporal resolution from a Geostationary Earth Orbit (GEO) for the first time. With the development of UV-visible spectrometers at sub-nm spectral resolution and sophisticated retrieval algorithms, estimates of the column amounts of atmospheric pollutants (O3, NO2, SO2, HCHO, CHOCHO and aerosols) can be obtained. To date, all the UV-visible satellite missions monitoring air quality have been in Low Earth orbit (LEO), allowing one to two observations per day. With UV-visible instruments on GEO platforms, the diurnal variations of these pollutants can now be determined. Details of the GEMS mission are presented, including instrumentation, scientific algorithms, predicted performance, and applications for air quality forecasts through data assimilation. GEMS will be onboard the GEO-KOMPSAT-2 satellite series, which also hosts the Advanced Meteorological Imager (AMI) and Geostationary Ocean Color Imager (GOCI)-2. These three instruments will provide synergistic science products to better understand air quality, meteorology, the long-range transport of air pollutants, emission source distributions, and chemical processes. Faster sampling rates at higher spatial resolution will increase the probability of finding cloud-free pixels, leading to more observations of aerosols and trace gases than is possible from LEO. GEMS will be joined by NASA's TEMPO and ESA's Sentinel-4 to form a GEO AQ satellite constellation in early 2020s, coordinated by the Committee on Earth Observation Satellites (CEOS)

Condition-based Selective Maintenance Optimization for a Large-scale Non-Markovian System

We consider selective maintenance that repairs severely degraded units in the system consisting of massive units. Under the assumption that units degrade independently in a finite number of states, we derive a fluid model that approximates the mean behavior of the system’s health condition. Our simulation study indicates that even if only a subset of units gets repaired, the system would asymptotically become a regenerative process as the maintenance operations are repeated over time. Based on this observation, we optimize the maintenance scheduling that triggers the maintenance operations based on the fraction of units at each degradation state in order to minimize long-run maintenance costs.1

Effects of newly developed compact robot-aided upper extremity training system (Neuro-X®) in patients with stroke: A pilot study

Objective: Robot-assisted rehabilitation therapy of the upper extremity after stroke has been studied widely; however, robotic devices remain expensive and bulky. The aim of this study was to evaluate the effects of a newly developed, compact upper extremity training system (Neuro-X®) in patients with chronic stroke. Design: Pilot study. Subjects: Fifteen patients with hemiplegia. Methods: Chronic patients with stroke underwent upper extremity training using a newly developed upper extremity training system (Neuro-X®; Apsun Inc., Seoul, Korea). Patients were evaluated using the Fugl-Meyer Assessment (FMA), Hand Function Test (HFT), Modified Ashworth Scale (MAS), and Korean Mini-Mental Status Evaluation (K-MMSE). The assessment started with “pre 1 evaluation” (A1), followed by repeated “pre 2 evaluation” (A2) after 6 weeks without receiving any treatment, in order to generate repeated baseline data. After the A2 evaluation, upper extremity training was performed for 6 weeks. Post-training evaluation (B) was performed after treatment. Obtained data (A1–A2–B) were compared. Results: During the non-intervention phase (A1 to A2), no significant changes were found in the aforementioned evaluations. However, in the intervention phase (A2 to B), results of the FMA and HFT, and K-MMSE scores, except the MAS score, increased significantly (p <0.05). Conclusion: The Neuro-X® training system improves functioning of the upper extremity and cognition in patients with stroke after 6 weeks of training