Enhanced optical output performance in InGaN/GaN light-emitting diode embedded with SiO2nanoparticles.

We demonstrated the InGaN/GaN-based light-emitting diodes (LEDs) with SiO2 nanoparticles embedded in nanopillar GaN template. With the SiO2 nanoparticles placed between the GaN nanopillars, subsequent overgrowth of GaN layer started only on the exposed tips of the nanopillars and rapidly switched to the lateral growth mode. This resulted in a high quality GaN layer "sitting" on the nanopillars and the layer of pores formed over the SiO2 nanoparticles. For multi-quantum-well LEDs grown on top of such template, ~3 fold increase in optical output was observed compared to reference samples. The effect is attributed mainly to the improved light extraction efficiency due to additional scattering in the nanopillars-SiO2-pores portion of the structure, also to the increased internal quantum efficiency caused by a decreased dislocation density and relaxed strain due to the GaN nanopillars.

Effect of Different Exercise Types on the Cross-Sectional Area and Lumbar Lordosis Angle in Patients with Flat Back Syndrome.

Flat back syndrome (FBS) is a sagittal imbalance wherein the normal spinal curvature is reduced. This study aimed to compare the effects of different exercise programs on the cross-sectional area (CSA) of the lumbar muscles, lumbar lordosis angle (LLA), lumbar disability, and flexibility in patients with FBS. Thirty-six females with flexible FBS were randomly allocated to the corrective exercise group (CEG, n = 12), resistance exercise group (REG, n = 12), and physical therapy group (PTG, n = 12). CEG and REG patients participated in a 12-week exercise intervention for 60 min three times per week. The CSA, LLA, Oswestry disability index (ODI), and sit-and-reach test were measured before and after intervention. CSA showed a significant difference between groups (p < 0.01), with CEG and REG demonstrating a significant increase (p < 0.05 and p < 0.05, respectively). LLA showed a significant difference between groups (p < 0.001); CEG showed a higher increase than did REG (p < 0.01) and PTG (p < 0.001). ODI also showed a significant difference between groups (p < 0.001), being lower in CEG than in REG (p < 0.001) and PTG (p < 0.001). Lumbar flexibility significantly improved in all groups, albeit with a significant difference (p < 0.001). Although corrective and resistance exercise programs effectively improve these parameters, corrective exercise is superior to other interventions for patients with FBS.

Effects of Different Types of Contraction Exercises on Shoulder Function and Muscle Strength in Patients with Adhesive Capsulitis.

Although several studies have reported the effect of exercise therapy for adhesive capsulitis (AC), studies on the comparison of different exercise types on shoulder muscle strength and function in patients with AC are lacking. This study aimed to investigate the effect of different exercise types on shoulder muscle strength and function in patients with AC. Thirty female patients with AC were categorized into an eccentric contraction exercise group (ECG, n = 15; age, 51.53 ± 4.73 years) and a concentric contraction exercise group (CCG, n = 15; age, 52.40 ± 4.03 years). The participants in each group performed a different exercise program three times per week for 60 min per session for 12 weeks. The range of motion (ROM) of the shoulder joint, visual analog scale, shoulder muscle strength, and Constant-Murley score (CMS) were measured before the intervention and after 12 weeks of the exercise intervention. Shoulder ROM in flexion (increase of 31%) and external rotation (ER) (increase of 54%) showed a significant improvement in the ECG (p < 0.05). Muscle strength in ER was significantly different between the two groups (p < 0.05). Pain severity showed improvement in the ECG (decrease of 61%) after the intervention (p < 0.01). The CMS in the ECG (increase of 48%) showed a greater improvement than that in the CCG after the intervention (p < 0.01). This study showed that eccentric contraction exercise had a more beneficial effect than concentric contraction exercise for improving shoulder muscle strength and function in females with AC.

[Clinical features of acute hepatitis A in recent two years].

BACKGROUND/AIMS: The purpose of this study was to characterize the clinical features of acute hepatitis A in Seoul and Gyeonggi province during the recent 2 years. METHODS: We reviewed the medical records of 222 patients who were diagnosed as acute hepatitis A between August 2005 and March 2007 at the Konkuk University Hospital and Korea University, Ansan Hospital. The clinical manifestation, serological tests, and image findings were analyzed. RESULTS: Median age of the patients was 28.1 years and the age groups of highest incidence were the second and third decade. The frequent symptoms were anorexia (66.4%), fatigue (49.2%), fever (47.7%), and abdominal discomfort (42.5%). Fourteen cases (6.3%) showed renal insufficiency, and hemodialysis was performed in one. Cholestatic hepatitis in 2 cases, relapsing hepatitis in 4 cases and prolonged hepatitis in 13 cases were observed. However, there was no case of fulminant hepatitis or death. The underlying diseases including chronic hepatitis B, diabetes mellitus and thyroid disorder did not affect the disease severity of hepatitis A. IgM anti-HAV was not detected initially in 6.7% of the patients. Anti-HEV (IgM) was detected simultaneously in 3 of 150 patients. CONCLUSIONS: The age of patients with acute hepatitis A has been increased in the recent years. Most patients recovered uneventfully. However, unusual patterns of severe hepatitis and renal insufficiency occurred in considerable number of cases. Follow-up serologic test for IgM anti-HAV is needed in seronegative cases with hepatitis A.

[A case of pedunculated leiomyoma found during colonoscopic examination for anal bleeding].

Gastrointestinal leiomyomas are commonly found in the stomach, and but 3% of them arises from the colon. Colonic leiomyomas are often found incidentally during colonoscopic examination. Most of patients with colonic leiomyoma are asymptomatic, but patients with large size leiomyoma occasionally have abdominal mass, hemorrhage, intestinal obstruction or perforation. Pedunculated leiomyomatous polyp is rare. Leiomyomatous polyps are occasionally misjudged as adenomatous polyps by endoscopist. We report a case of pedunculated leiomyomatous colonic polyp in 65 year-old female patient. She has complained of intermittent hematochezia and lower abdominal discomfort for 5 months. During colonoscopy, an 1 cm sized long pedunculated polyp at the splenic flexure was detected. It was removed by colonoscopic snare polypectomy. Leiomyomatous polyp was confirmed by microscopic and immunohistochemical findings.

Facile fabrication of free-standing light emitting diode by combination of wet chemical etchings.

Free-standing GaN light-emitting diode (LED) structure with high crystalline quality was fabricated by combining electrochemical and photoelectrochemical etching followed by regrowth of LED structure and subsequent mechanical detachment from a substrate. The structural quality and composition of the regrown LED film thus produced was similar to standard LED, but the photoluminescence and electroluminescence intensity of the LED structures on the etched template were several times higher than for standard LED. The performance enhancement was attributable to additional light scattering and improved crystalline quality as a result of the combined etching scheme.