The incidence and risk factors for deep vein thrombosis after kidney transplantation in Korea: single-center experience.

BACKGROUND: The incidence of deep vein thrombosis (DVT) after kidney transplantation (KT) and the risk factors are still unknown in Korean patients. Determining the need for appropriate DVT prophylaxis is difficult when considering the low incidence of DVT in the Asian population. The aim of this study was to investigate the incidence of DVT occurring 3 months after KT, the DVT occurrence pattern, and risk factors in Korean patients. METHODS: Data from a total of 393 patients who underwent KT from November 2009 to December 2012 were analyzed. Color duplex ultrasonography was used for the diagnosis or screening of DVT in all patients pre-operatively and on post-operative days 7, 14, 28, and 90. RESULTS: The cumulative 3-month incidence of DVT after KT was 4.6%, and there was one symptomatic DVT. Patients with DVT were older than those without DVT at the time of transplantation (52.8 vs. 44.6, p < 0.001). According to univariate and multivariate analysis, older age was identified as a risk factor for DVT at the time of transplantation, whereas history of DVT did not reach statistical significance. There were no deaths related to DVT or pulmonary embolism. CONCLUSIONS: Pharmacological prophylaxis after KT is not necessary because of the low incidence of DVT in Korean patients, and instead, we suggest that long-term mechanical prophylaxis of at least 3 months can be a suitable option. Patients older than 50 years of age have a higher risk of developing DVT, and careful observation is needed in these patients.

Mechanical thromboprophylaxis is sufficient to prevent the lower extremity deep vein thrombosis after kidney transplantation.

PURPOSE: Deep vein thrombosis (DVT) is a severe and common complication that occurs after the major operation. Despite the commonality of DVT there is limited data on the incidence of DVT after kidney transplantation (KT). Furthermore, most studies have been retrospective in design and were conducted in western countries. The aim of this study was to evaluate the incidence of lower extremity DVT with mechanical thromboprophylaxis within 1 month of KT in Korea. METHODS: A total of 187 consecutive patients who underwent KT were included in this study. Patients used a graduated elastic stocking (n = 93) or an intermittent pneumatic compression device (n = 94) to prevent DVT. The frequency of DVT during the first month after KT was evaluated using serial color duplex ultrasound on postoperative days 7 ± 2, 14 ± 2, and 28 ± 3. All patients were tested for eight thrombophilic factors before KT. RESULTS: DVT occurred in four patients (2.1%) during the first month after KT. All DVT developed in the graduated elastic stocking group. Interestingly, none of the patients had the factor V Leiden mutation or the prothrombin gene 20210A mutation. CONCLUSION: The incidence of DVT in this study was relatively lower than that of western populations. We did not encounter a factor V Leiden mutation or a prothrombin gene 20210A mutation in our study population. These findings suggest that inherited thrombophilic risk factors may be partially responsible for the difference in DVT incidence rates between different nationalities and/or ethnicities.

Production of bioethanol from lignocellulose: Status and perspectives in Korea.

The current status and challenges associated with the production and utilization of cellulosic ethanol in Korea are reviewed in this paper. Cellulosic ethanol has emerged as a promising option for mitigating Korea's CO(2) emissions and enhancing its energy security. Korea's limited biomass resources is the most critical barrier to achieving its implementation targets for cellulosic ethanol. Efforts to identify new suitable biomass resources for cellulosic ethanol production are ongoing and intensive. Aquatic biomasses including macroalgae and plantation wastes collected in the Southeast Asia region have been found to have great potential as feedstocks for the production of cellulosic ethanol. R&D explorations into the development of technologies that can convert biomass materials to ethanol more efficiently also are underway. It is expected that cellulosic ethanol will be in supply from 2020 and that, by 2030, its use will have effectively reduced Korea's total gasoline consumption by 10%.

Production and characterization of biodiesel from tung oil.

The feasibility of biodiesel production from tung oil was investigated. The esterification reaction of the free fatty acids of tung oil was performed using Amberlyst-15. Optimal molar ratio of methanol to oil was determined to be 7.5:1, and Amberlyst-15 was 20.8 wt% of oil by response surface methodology. Under these reaction conditions, the acid value of tung oil was reduced to 0.72 mg KOH/g. In the range of the molar equivalents of methanol to oil under 5, the esterification was strongly affected by the amount of methanol but not the catalyst. When the molar ratio of methanol to oil was 4.1:1 and Amberlyst-15 was 29.8 wt% of the oil, the acid value decreased to 0.85 mg KOH/g. After the transesterification reaction of pretreated tung oil, the purity of tung biodiesel was 90.2 wt%. The high viscosity of crude tung oil decreased to 9.8mm(2)/s at 40 degrees C. Because of the presence of eleostearic acid, which is a main component of tung oil, the oxidation stability as determined by the Rancimat method was very low, 0.5h, but the cold filter plugging point, -11 degrees C, was good. The distillation process did not improve the fatty acid methyl ester content and the viscosity.

Pretreatment characteristics of waste oak wood by ammonia percolation.

A log of waste oak wood collected from a Korean mushroom farm has been tested for ammonia percolation pretreatment. The waste log has different physical characteristics from that of virgin oak wood. The density of the waste wood was 30% lower than that of virgin oak wood. However, there is little difference in the chemical compositions between the woods. Due to the difference in physical characteristics, the optimal pretreatment conditions were also quite different. While for waste oak the optimum temperature was determined to be 130 degrees C, for virgin oak wood the optimum pretreatment was only achieved at 170 degrees C. Presoaking for 12 h with ammonia solution before pretreatment was helpful to increase the delignification efficiency.

Blending effects of biodiesels on oxidation stability and low temperature flow properties.

To improve the oxidation stability and the low temperature flow properties of a biodiesel mixture, the dependence of the oxidation stability and the cold filter plugging point (CFPP) on the fatty acid compositions was examined. Three different kinds of biodiesels, palm, rapeseed, and soybean biodiesels, were blended with the different weight ratios. The oxidation stability and the CFPP of the blended biodiesels had a close relationship with the compositions of the major fatty acid components. The oxidation stability of the blended biodiesels decreased as the total contents of the linoleic and linolenic acids increased. The correlation was obtained as Y=117.9295/X+2.5905 (0

A comparative study of methods of estimating kidney length in kidney transplantation donors.

BACKGROUND: Knowledge of kidney size is important for clinical assessment of renal disease. However, there are few studies on methods of assessing kidney size. The purpose of this study was to determine the usefulness of body index and radiological measurements for prediction of kidney size. METHODS: One hundred and twenty five donors were enrolled. The sizes of donor kidneys obtained after nephrectomies for kidney transplantations were documented and the correlation coefficient between kidney length and body index was calculated. Kidney length was estimated from the distance between the first and third lumbar vertebrae (L1-3), intravenous pyelograms (IVPs), abdominal ultrasonography (US), and abdominal computed tomography (CT). RESULTS: Normal adult kidneys were 11.08 +/- 0.96 cm long, 6.25 +/- 0.67 cm wide, 4.73 +/- 0.65 cm thick and weighed 196.3 +/- 41.0 g. Correlation coefficients between kidney length and body height, body weight, body surface area and total body water content were 0.29, 0.31, 0.26, and 0.32, respectively. The difference between actual and predicted kidney lengths was -0.6 cm for L1-3, +1.2 cm for IVPs, -0.7 cm for abdominal US, -0.8 cm for transverse CT section, and -0.5 cm for coronal CT section. CONCLUSIONS: Abdominal coronal CT section predicted kidney length more accurately than other radiological methods, but all radiological methods were associated with prediction errors. As kidney length was correlated with body index, it is suggested that body index is the most useful and simplest method of estimating kidney size as an adjunct to treatment decisions concerning renal disease.

Effects of mixture ratio and hydraulic retention time on single-stage anaerobic co-digestion of food waste and waste activated sludge.

The biochemical methane potential (BMP) test was used to evaluate the anaerobic biodegradabilities of food waste (FW), waste activated sludge (WAS), and the mixtures having the ratios of 10:90, 30:70, 50:50, 70:30, and 90:10 (FW:WAS) on a volatile solid (VS) basis. The carbon/nitrogen (C/N) ratio and the biodegradability of the mixtures improved from 6.16 to 14.14 and increased from 36.6 to 82.6% as the FW proportion of the mixture increased from 10 to 90%, respectively. The stability and performance of the single-stage anaerobic digester (SSAD) for the co-digestion of FW and WAS were investigated, operated at the hydraulic retention times (HRTs) of 10, 13, 16, and 20 days with five mixtures at 35 degrees C, respectively. During all the experiments, there were no indication of failure such as low pH, insufficient alkalinity, ammonia inhibition, and the accumulation of volatile fatty acids (VFAs) in any of the digesters, and the buffer capacity was the highest in the digester fed with a feed mixture of 50:50. The optimum operating conditions of the SSAD were found to be an HRT of 13 days and a mixture of 50:50 in terms of the buffer capacity of the digester and the effluent VS concentration, the methane content of the biogas produced and the specific methane production (SMP). The VS removal efficiency, biogas production rate (GPR), and SMP in this condition achieved 56.8%, 1.24 m3 m(-3) d(-1) and 0.321 m3 CH4 kg(-1) VS(fed)(-1) with an organic loading rate (OLR) of 2.43 kg VS m(-3) d(-1).

Pretreatment of swine wastewater using anaerobic filter.

Efforts were made to assess the efficiency of an anaerobic filter packed with porous floating ceramic media and to identify the optimum operational condition of anaerobic filter as a pretreatment of swine wastewater for the subsequent biological removal of nitrogen and phosphorus. A stepwise decrease in hydraulic retention time (HRT) and an increase in organic loading rate (OLR) were utilized in an anaerobic filter reactor at mesophilic temperature (35 degrees C). The optimum operating condition of the anaerobic filter was found to be at an HRT of 1 d. A soluble chemical oxygen demand (COD) removal efficiency of 62% and a total suspended solids removal efficiency of 39% at an HRT of 1 d were achieved with an OLR of 16.0 kg total COD/(m3.d), respectively. The maximum methane production rate approached 1.70 vol of biogas produced per volume of reactor per day at an HRT of 1 d. It was likely that the effluent COD/total Kjeldahl nitrogen ratio of 22, the COD/total phosphorous ratio of 47, and the high effluent alkalinity >2500 mg/L as CaCO3 of the anaerobic filter operated at an HRT of 1 d was adequate for the subsequent biological removal of nitrogen and phosphorus.

Single-stage anaerobic codigestion for mixture wastes of simulated Korean food waste and waste activated sludge.

Korean food waste was treated with a single-stage anaerobic codigester (SSAD) using waste activated sludge (WAS) generated from a municipal wastewater treatment plant. The stability and performance of the system was analyzed. The C/N ratio was improved with increasing food waste fraction of feed mixture. The pH, alkalinity, and free ammonia nitrogen concentration were the parameters used to evaluate the digester's stability. The experimentally determined values of the parameters indicated that there were no methane inhibitions in the digester. Digester performance was determined by measuring the total chemical oxygen demand TCOD), volate solids (VS) removal, methane content in biogas, methane production rate (MPR), and specific methane productivity. Methane content in biogas and MPR were significantly dependent on hydraulic retention time (HRT) and ratio of food waste to WAS. The methane content in biogas decreased at shorter HRT or higher organic loading rate (OLR) with increased food waste fraction. Concerning the performance of the codigester, the optimum operating condition of the SSAD was found to be at an HRT of 10 d with a feed mixture ratio of 50% food waste and 50% WAS. A TCOD removal efficiency of 53.6% and a VS removal efficiency of 53.7% were obtained at an OLR of 5.96 kg of TCOD/(m3 d) and 3.14 kg of VS/(m3 d), respectively. A maximum MPR of 1.15 m3 CH4/(m3 d) and an SMP of 0.37 m3 CH4/kg of VSfeed were obtained at an HRT of 10 d with a methane content of 63%.

Effects of SO2 and NO on growth of Chlorella sp. KR-1.

Effects of the toxic compounds in flue gas, SOx and NOx, on growth of Chlorella sp. KR-1 have been determined. Although growth of KR-1 was suppressed by the toxic compounds, KR-1 exhibited excellent tolerances to SOx compared to other algal strains. When Chlorella KR-1 was cultured with the model gas containing 60 ppm SO2, the linear growth rate was 1.24 g/l day which is about 25% lower than that of the control culture aerated with the gas mixture containing no toxic compounds, SO2 and NO. KR-1 could grow even with the model gas containing 100 ppm SO2 and the linear growth rate of KR-1 in the culture was 0.78 g/l day. The period for lag phase was increased with increasing of SO2 concentration that also resulted in the decrease of the linear growth rate and the maximum cell concentration. Direct CO2 fixation by Chlorella KR-1 has been successfully done using actual flue gases from a liquified natural gas (LNG)- or diesel-fueled boiler. These results indicated that Chlorella KR-1 may be applied for direct CO2 fixation from actual flue gas.