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The AC loss in a large superconducting magnet coil shows a tendency to be changed after assembly. For the ac loss measurement of the Korea Superconducting Tokamak Advanced Research (KSTAR) superconducting coils after assembly, several current scenarios, trapezoidal pulses and a DC offset sinusoidal pulses, were applied to the PF1 Upper (U) and Lower (L) coils during the commissioning. The measurement was done once before and once after the plasma discharge experiments. All coil data were obtained by the tokamak monitoring system and helium distribution system which were designed to measure temperature, pressure, and mass-flow at both inlets and outlets of the coils. The PF1 coils of the cable-in-conduit conductor type were made of Nb3Sn superconducting strands, whose winding scheme is 20 layers with each layer having 9 turns. Each has 10 cooling channels for the heat removal by the supercritical helium at 4.5 K. For the trapezoidal pulse tests, the current was increased up to 4 kA with several different ramp rates and a 2 kA DC offset and 0.5 kA sine waves with different frequencies from 0.1 Hz to 0.3 Hz were applied to the coil. According to the analyses, the AC loss was slightly decreased for the same condition after 700 plasma shots. It was believe that such a result was due to reduced inter-strand resistances which changed the transverse resistance between the inter-strands. The coupling time constant was estimated to be 32 ms in the trapezoidal tests and 13.6 ms for the DC offset sinusoidal pulses. The former is larger than the latter because of the effect of the jacket eddy current loss due to Incoloy 908 which is a ferromagnetic material. Considering the jacket eddy current losses, the coupling time constant was recalculated and the value estimated to be about 13 ms for all current wave forms during first commissioning. [ABSTRACT FROM AUTHOR]

Recent commissioning of two major fully superconducting (SC)-shaped tokamaks, Experimental Advanced Superconducting Tokamak (EAST) and Korean Superconducting Tokamak Advanced Research (KSTAR), represents a significant advance in magnetic fusion research. The key to commissioning success in these complex and unique tokamaks was as follows: 1) use of a robust, flexible plasma control system (PCS) based on the validated DIII-D design; 2) use of the TokSys design and modeling environment, which is tightly coupled with the DIII-D PCS architecture for first-plasma scenario development and plasma diagnosis; and 3) collaborations with experienced internationally recognized teams of tokamak operations and control experts. We provide an overview of the generic modeling environment and plasma control tools developed and validated within the DIII-D experimental program and applied through an international collaborative program to successfully address the unique constraints associated with the startup of these next-generation tokamaks. The unique characteristics of each tokamak and the machine constraints that must be included in device modeling and simulation, such as SC coil current slew rate limits and the presence of nonlinear magnetic materials, are discussed, along with commissioning and initial operational results. Lessons learned from the startup experience in these devices are summarized, with special emphasis on ramifications for International Thermonuclear Experimental Reactor (ITER). [ABSTRACT FROM AUTHOR]

Background: This study was designed to determine the prevalence of depression among hemodialysis (HD) patients from urban hospitals in Korea, to illustrate demographic factors and biomarkers associated with depression and health-related quality of life (HRQOL), and to demonstrate association between depression and HRQOL., Patients and Methods: For this multicenter, cross-sectional study, 160 HD patients from 3 university teaching hospitals and 3 local dialysis units in Korea were enrolled. Korean Beck's depression inventory and Korean version of Kidney Disease Quality of Life short form, version 1.3 (KDQOL-SFTM 1.3) were used to evaluate depression and quality of life, respectively., Results: Depression was found in 51 out of 160 (31.9%) patients. Old age (> 60 years old), low hemoglobin level (< 10 g/dl), and low economic status were associated with depression, and old age (OR 6.138, p = 0.001) was the most important risk factor among them. Old age, female gender, presence of diabetes mellitus, high comorbidity index score (modified Charlson comorbidity index > or = 6), hypoalbuminemia (< 4.0 g/dl), and high CRP (> 0.5 mg/dl) were common factors associated with decreased HRQOL. Depression and HRQOL showed inverse linear relationship., Conclusions: Moderate to severe depression was common in maintenance HD patients in Korea. Among factors associated with depression and decreased HRQOL, some characteristics are potentially modifiable by social and medical intervention. Further prospective studies are warranted to see whether depression and HRQOL can be improved by modifying these factors.

Aims: Megsin is a mesangial cell-predominant gene which belongs to the serpin superfamily. The expression of megsin was upregulated and coincided with mesangial proliferation and extracellular matrix expansion in IgA nephropathy (IgAN). In the present study, we evaluated the influence of the C2093T and C2180T polymorphism within the 3' untranslated region (3'UTR) of megsin gene and its haplotypes on the development and progression of Korean IgAN patients., Methods: Korean IgAN patients (n = 260) with a minimal follow-up of 4 years were recruited. Healthy subjects with normal renal function, normal urinalysis and normotension (n = 315) were included as controls. The polymorphisms were determined by the 5' nuclease allelic discrimination assay, and the haplotypes were constructed using the Phase program., Results: The C2093T and C2180T genotype and allele frequencies were not different significantly between IgAN patients and controls. In C2093T polymorphism, patients with CC genotype showed a better renal survival than those with CT or TT genotypes by Kaplan-Meier analysis (p = 0.027). The megsin C2093T polymorphism remained an independent risk factor for progression (Cox regression model, HR for TT genotype: 3.52, 95% CI 1.69 - 7.34; HR for CT genotype: 2.15, 95% CI 1.30 - 3.57). In C2180T polymorphism, patients with TT genotype showed a better outcome than those with CC or CT genotypes (p = 0.025). The C2180T polymorphism was also an independent risk factor for progression (HR for CC genotype: 4.05, 95% CI 1.93 - 8.51; HR for CT genotype: 2.35, 95% CI 1.40 - 3.94). The two alleles showed linkage disequilibrium in phased haplotype. The patients with 2093T-2180C haplotype showed a poor renal survival compared to those with 2093C-2180T haplotype (p = 0.028). The haplotype remained an independent risk factor for progression (HR for 2093T-2180C haplotype: 2.01, 95% CI 1.44 - 2.81)., Conclusions: Our results suggest that the 2093T-2180C haplotype at the 3'UTR of megsin gene is associated with rapid disease progression in Korean IgAN patients. This is the reverse of the results from the Chinese IgAN patients. Further studies are strongly needed to elucidate the reasons of disparity.

We experienced a case of adult T cell leukemia/lymphoma (ATLL) in a 48-year-old Korean female, who has never been abroad since birth and no history of blood transfusion. The patient had hypercalcemia and multiple lymphadenopathy. Histopathologic study of left cervical lymph node (LN) and bone marrow (BM) revealed that infiltrates of malignant lymphoid cells were composed of small, medium and large cells with pleomorphic nuclei. Smears of peripheral blood (PB) showed lymphopenia (16%) with the appearance of a few atypical lymphoid cells (less than 2%), but not the typical clover leaf cells seen in ATLL. Immunophenotypic study of LN and BM revealed T cell phenotype. PB showed increased CD4+ T cell (T(H), CD3/CD4+, 57%) and decreased CD8+ T cell counts (T(S), CD3/CD8+, 6.7%). The sera of the patient and her family were reactive for HTLV-I antibody. The specific sequences of pol, env, and tax of HTLV-I DNA were detected in the lymphoma cells and peripheral blood mononuclear cells (PBMC) using polymerase chain reaction. Ultrastructural examination of PBMC confirmed numerous type c virus particles in extracellular space. This case was an acute type of ATLL without overt leukemic features in PB. Despite chemotherapy and intensive conservative treatment, she died 3 months after admission.

Body temperatures of winter-resident Korean bats typically range from 10 degrees to 40 degrees C between August and September and from 3 degrees to 15 degrees C between January and April. To learn how behavior and the motor systems of heterothermic bats respond to this body-temperature variation, we examined whole-organism performance and the temperature-dependence of contractile properties of flight muscle in Murina leucogaster ognevi. In winter and midspring, the lowest limits of body temperature were 8 degrees C for biting and crawling, 16 degrees C for visually observable shivering, 22 degrees C for wing flapping (without powered flight), and 28 degrees C for aerial flight. In summer, the lowest temperature limits changed little for biting and wing flapping, but the temperature limits increased about 3 degrees C for crawling, shivering, and flight. Maximum isometric tetanic tension of the isolated biceps brachii muscle was almost insensitive to tissue temperatures between 10 degrees and 40 degrees C, with an average temperature coefficient of 1.02 in summer and of 0.96 in winter. Rate of tetanic tension production between 10 degrees and 40 degrees C and shortening velocity and power between 15 degrees and 25 degrees C were temperature sensitive, with average temperature coefficients of 1.3-2.3. Seasonal differences in contractile properties within each temperature were not significant, except for maximum tetanic tension at 30 degrees - 40 degrees C. Thus, the motor system of the bats had functional capacity over the range of body temperature experienced in winter to summer. The temperature-dependence of behavior was consistent with muscle physiology. The defensive behaviors, like biting and crawling, observed at 8 degrees - 12 degrees C body temperature could be exerted by using temperature-independent tetanic tension, whereas activities, such as flight, that require power generation would be restricted to higher body temperatures by temperature-sensitive rate properties. Some rate processes appeared to be more temperature sensitive in summer than in winter.