• Korean Journal of Transplantation
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• v.32 no.4
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• pp.75-83
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• 2018

Background: This study was designed to analyze the clinical usefulness of mycophenolic acid trough concentration monitoring in kidney transplantation patients who were maintained with cyclosporine. Methods: The data of patients who underwent mycophenolic acid trough concentration monitoring after their first kidney transplant between November 2006 and August 2013 and were prescribed with cyclosporine, mycophenolate, and methylprednisolone were reviewed retrospectively. Cox analysis was used to analyze the risk factors for acute rejection within 1 year post-transplantation. Results: Among 90 patients, 41 (45.6%) achieved both the target levels of cyclosporine and mycophenolic acid, while three patients (3.3%) failed to achieve the target level of either cyclosporine or mycophenolic acid. Nine patients (10.0%) only achieved the mycophenolic acid target level and 37 patients (41.1%) only achieved the cyclosporine target level. While patients who achieved only the mycophenolic acid target concentration had no statistically increased risk compared to patients who achieved both target levels (hazard ratio [HR], 1.569; 95% confidence interval [CI], 0.316 to 7.778; P=0.581), patients who only achieved the cyclosporine target concentration showed an increased risk of rejection compared to the both achievement group (HR, 4.112; 95% CI, 1.583 to 10.683; P=0.004). Patients who had no achievement in the target levels showed significantly increased rejection risk compared to the patients who achieved both target levels (HR, 17.811; 95% CI, 3.072 to 103.28; P=0.001). Conclusions: Mycophenolic acid trough concentration monitoring combined with cyclosporine trough concentration monitoring is useful for avoiding acute cellular rejection if the first 1 year post-transplantation.

• Korean Journal of Clinical Pharmacy
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• v.20 no.3
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• pp.221-228
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• 2010

In 2009, American Journal of Health-System Pharmacy (AJHP) recommended that targeting vancomycin trough concentrations of 10 mg/L or more because of therapeutic failure and potential risk of developing vancomycin resistance. Therefore, new dosage guidelines that could achieve to these higher target were needed. The aims of this study were to develop dosage guidelines targeting new vancomycin trough concentration and to evaluate the performance of these new guidelines. All data analysis were performed using NONMEM(R). Population pharmacokinetic model was first developed from vancomycin dosage and concentration data collected retrospectively during routine therapeutic drug monitoring in 441 patients, then new vancomycin dosage guidelines were developed by using the model to predict vancomycin trough and peak concentrations in a simulated dataset. The estimates, such as, vancomycin concentration trough level, time to achieve target level, mean error were performed to evaluate and compare difference between conventional dosage and new dosage guidelines. The proposed dosage guidelines were predicted to achieve 43.5% of vancomycin trough level within 10~20 mg/L, which is significantly higher than current guidelines (26.3%). Time to achieve target trough level was 19.4 hours in new guidelines comparing to 93.1 hours in the conventional dosage. Thus, new vancomycin dosage guidelines have been developed to achieve new target trough concentrations earlier and more consistently than conventional guidelines.

• Journal of the Korean Chemical Society
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• v.29 no.3
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• pp.271-276
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• 1985

An anomalous absorbance-temperature profile of calf thymus DNA, having a trough preceding the initiation of the melting, occurs at the spermine concentration, where the DNA collapses into a compact structure. The cooperativity, enthalpy, and the midpoint of the phase transition to the trough region are more sensitive to ethidium bromide than those of the Tm region. As the concentration of ethidium bromide added is increased, the peak size of the trough is decreased, while the Tm remains essentially constant.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.4
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• pp.465-481
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• 2004

We determined Asian dust days by constructing the standard of Asian dust using PM$_{10}$ concentrations ($\geq$150 $\mu\textrm{g}$m$^{-3}$ , 24-hr average) and TOMS aerosol index ($\geq$0.7) for 5 years (1998-2002), and grouped Into long-lasted cases (LLCs, $\geq$4 days) and short-lasted cases (SLCs, $\leq$2 days) concerning the mean lasting time (about 3 days) of Asian dust. Further we performed the specific analyses associated with concentration variations and synoptic conditions by using PM$_{10}$ and TOMS data, weather maps during the dusty cases (LLCs and SLCs). As a result, the LLCs (9 cates) had large variations of PM$_{10}$ concentration as the mean of 131.1$\mu\textrm{g}$m$^{-3}$ and the maximum mean of 379.8$\mu\textrm{g}$m$^{-3}$ , and showed dominant features the continuous passage of deep trough caused by blocking effect and weak trough (56%, 5 cases) over Korea. The SLCs (11 cases) had relatively small variations of PM$_{10}$ concentration as the mean of 133.3$\mu\textrm{g}$m$^{-3}$ and the maximum mean of 247.2$\mu\textrm{g}$m$^{-3}$ , and showed passage of one weak trough (64%, 7 cases) over Korea. Thereafter, the case studies (April 7-13, 2002 of LLC and March 23-24, 2000 of SLC) performed by the simulation of MM5 with meteorological variables of the horizontal wind, potential temperature, isentropic potential vorticity, and helped to better understand the features of synoptic conditions in connection with the concentration variations for each case.

• Journal of Korean Society of Steel Construction
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• v.12 no.3 s.46
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• pp.239-250
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• 2000

This study investigates the mechanical behavior on trough rib to crossbeam joint in orthotropic steel plate decks, specially emphasizing on the effect of diaphragm inside trough rib on the fatigue behavior of slit by static and fatigue tests. In particular, the effects of diaphragm on in-plane stress and out-of-plane stress, stress concentration, propagation of fatigue cracks at the silt are studied. With the result of experiment and numerical analysis, we have estimated the fatigue strength using the nominal stress and hot-sport stress. The details with diaphragm have occurred about 50% stress reduction at trough rib part of trough rib to crossbeam joint than the detail without diaphragm, however, the lower parts of crossbeam have occurred much more stress. Initial crack size or slit have an considerable influence on the propagation of fatigue cracks due to V-notch. The fatigue strength category of the details without diaphragm has higher value than fatigue limit, whereas that of the details with diaphragm is estimated lower than fatigue limit.

• Bulletin of the Korean Chemical Society
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• v.12 no.3
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• pp.262-264
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• 1991

An anomalous absorbance-temperature profile of calf thymus DNA, having a hypochromic trough just before the rise the $T_m$-region phase, occurs at the spermine concentration where the DNA collapses into a compact structure. The trough phase can be eliminated by the addition of ethidium bromide and also by a hydrophobic environment.

• Journal of Korean Society of Steel Construction
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• v.8 no.3 s.28
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• pp.13-20
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• 1996

With the adoption of welded joints rather than bolted joints, we investigate the fatigue strength and the fatigue crack initiation of U-type trough rib and welded specimen with misalignment in a steel deck plate. The stress concentration factor of welded specimens with a misalignment is also verified by a finite element method. The main conclusions obtained from this study are as follows Experimental results of full-scaled U-type trough rib models have indicated that fatigue life depends on misalignments of welded joints in steel deck plate ; The more misalignments are, the less the fatigue life is. It has also shown that fatigue crack propagates from the welded root to the bead surface. We have also obtained the same results from both the fatigue test of welded specimens with a misalignment and the stress analysis of a finite element method.

• Proceedings of the Membrane Society of Korea Conference
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• 2001.05a
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• pp.93-97
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• 2001

• Journal of the Korean Chemical Society
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• v.29 no.5
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• pp.533-538
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• 1985

To investigate the importance of the hydrophobic interaction in the spermine-induced collapse of DNA to a compact structure, the effect of urea on the anomalous absorbance-temperature profile of calf thymus DNA has been investigated. With the increase of the urea concentration, the trough phase of the anomalous absorbance-temperature profile was eliminated eventually. The cooperativity, enthalpy, and the midpoint of the transition to the trough region are more sensitive to urea than those of the Tm-region transition. The present data of the adverse effect of urea, a hydrophobic environmental reagent, on the thermal stabilization of the condensed state of DNA, suggest that hydrophobic interaction may play an important role in the stabilization of the tertiary structure of the collapsed state of DNA.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.6
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• pp.545-554
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• 1998

The diurnal variation of O3 concentration shows two peaks, the first peak at noontime and the secondary peak at night. In order to show why the secondary peak, high nocturnal O3 concentration, occurs without sunlight which is a essential factor of a photochemical response, the O3 concentration, several weather elements and synoptic weather map were used for June∼September at 1995, 1996. The mean concentration of high nocturnal O3 concentration days is higher by 5.4 ppb than that of low nocturnal O3 concentration days. The nocturnal O3 concentration is higher than that of diurnal O3 concentration during high nocturnal O3 concentration days, at July, 1995 and June, 1996. The high nocturnal O3 concentration is related to low air pressure, high cloud cover and high wind speed. The correlation coefficient, r. between nocturnal O3 concentration and wind speed, pressure and cloud cover is 0.387, -0.218, and 0.194, respeftiviely. It is interesting that the O3 concentration increases at Pusan when the typhoon passes by. The same result showed at Taegu when the typhoon FAYE passed by. According to the analysis of nocturnal O3 concentration for June∼September at 1995 and 1996, it seems that the high nocturnal O3 concentration relates to the trough and cyclones passing by Pusan.