• Journal of Life Science
• /
• v.24 no.10
• /
• pp.1110-1117
• /
• 2014

Tidal flats are continuously contaminated by human activities. This study assessed the bioremediation efficiency of tidal flat soil using microcosm reactors and microorganisms originating from the tidal area. We screened 135 bacterial strains that produce extracellular enzymes from the tidal area located in the North port of Incheon bay. Two bacterial strains (Pseudoalteromonas sp. and IC35 Halothiobacillus neapolitanus IC_S22) were selected and used in the microcosm reactors, which were specially designed to functionally mimic the ecological conditions of the tidal flats. Pseudoalteromonas sp. IC35 was selected based on its relatively high activity of the enzymes amylase, cellulose, lipase, and protease. Halothiobacillus neapolitanus IC_S22 was selected for oxidation of sulfur. The M1 and M2 microcosm reactors were operated by continuous feeding of seawater under the same conditions, but M2 was first inoculated with Pseudoalteromonas sp. IC35 before the seawater feeding. The initial COD in both the M1 and M2 microcosm reactors was 320 mg/l. The final COD was 21 mg/l (M1) and 7 mg/l (M2). The M3 and M4 microcosm reactors were operated by continuous feeding of seawater under the same conditions, but M4 was first inoculated with H. neapolitanus IC_S22. The initial sulfate concentration in both the M3 and M4 microcosm reactors was 660 mg/l, and the maximum sulfate concentration was 1,360 mg/l (M3) and 1,600 mg/l (M4).

• Journal of Life Science
• /
• v.27 no.1
• /
• pp.100-121
• /
• 2017

The sexual reproduction of the unicellular green alga Chlamydomonas is reviewed for a comprehensive understanding of the complex processes. The sexual life cycle of C. reinhardtii is distinguished into five main stages: gametogenesis, gamete activation, cell fusion, zygote maturation, and meiosis and germination. Gametogenesis is induced by nitrogen starvation in the environment. C. reinhardtii has two mating types: mating type plus ($mt^+$) and mating type minus ($mt^-$), controlled by a single complex mating type locus ($MT^+$ or $MT^-$) on linkage group VI. In the early gametogenesis agglutinins are synthesized. The $mt^+$ and $mt^-$ agglutinins are encoded by the autosomal genes SAG1 (Sexual AGglutination1) and SAD1 (Sexual ADhesion1), respectively. The agglutinins are responsible for the flagellar adhesion of the two mating type of gametes. The flagellar adhesion initiates a cAMP mediated signal transduction pathways and activates the flagellar tips. In response to the cAMP signal, mating structures between two flagella are activated. The $mt^+$ and $mt^-$ gamete-specific fusion proteins, Fus1 and Hap2/Gcs1, are present on the plasma membrane of the two mating structures. Contact of the two mating structures leads to develop a fertilization tubule forming a cytoplasmic bridge between the two gametes. Upon fusion of nuclei and chloroplasts of $mt^+$ and $mt^-$ cells, the zygotes become zygospores. It is notable that the young zygote shows uniparental inheritance of chloroplast DNA from the $mt^+$ parent and mitochondrial DNA from the $mt^-$ parent. Under the favorable conditions, the zygospores divide meiotically and germinate and then new haploid progenies, vegetative cells, are released.

• Analytical Science and Technology
• /
• v.27 no.3
• /
• pp.172-180
• /
• 2014

Fenpyrazamine which is a pyrazole fungicide class for controlling gray mold, sclerotinia rot, and Monilinia in grapevines, stone fruit trees, and vegetables has been registered in republic of Korea in 2013 and the maximum residue limits of fenpyrazamine is set to grape, peach, and mandarin as 5.0, 2.0, and 2.0 mg/kg, respectively. Very reliable and sensitive analytical method for determination of fenpyrazamine residues is required for ensuring the food safety in agricultural products. Fenpyrazamine residues in samples were extracted with acetonitrile, partitioned with dichloromethane, and then purified with silica-SPE cartridge and eluted with hexane and acetone mixture. The purified samples were determined by HPLC-UVD and confirmed with LC-MS and quantified using external standard method. Linear range of fenpyrazamine was between $0.1{\sim}5.0{\mu}g/mL$ with the correlation coefficient (r) 0.999. The average recovery ranged from 71.8 to 102.7% at the spiked level of 0.05, 0.5, and 5.0 mg/kg, while the relative standard deviation was between 0.1 and 7.3%. In addition, limit of detection and limit of quantitation were 0.01 and 0.05 mg/L, respectively. The results revealed that the developed and validated analytical method is possible for fenpyrazamine determination in agricultural product samples and will be used as an official analytical method.

• Journal of Chest Surgery
• /
• v.42 no.3
• /
• pp.350-354
• /
• 2009

Background: Complicated pleural space occupying lesions (SOL) have been treated by thoracentesis, closed thoracotomy drainage (CTD) or surgical intervention with using a video thoracosocpe or open thoracotomy depending on the extent of the disease. With the development of video assisted thoracoscopic surgery (VATS), VATS pleural adhesiolysis and decortication have revealed good results as compared to those for open thorcotomy. To assess the effectiveness of VATS pleural adhesiolysis and decortication, we retrospectively analyzed the medical record and radiologic findings of the patients with complicated pleural SOL and who were treated by this surgery. Material and Method: From May 1996 to April 2006, 64 patients (mean age: 41.8 years) with complicated pleural SOL underwent 65 VATS. To analyze the surgical outcome, we classified the postoperative findings on the simple chest X-rays into 4 classes as Class I: no or minimal pleural lesion, Class II: blunting of the cardiophrenic angle and mild pleural thickening, Class III: an elevated diaphgram or persistent lung collapse and Class IV: complicated or recurrent effusion. Result: Before VATS, the patients underwent the diagnostic or therapeutic procedures: single or repeat diagnostic tapping for 41, thoracoscotomy drainage for 11, pigtail catheter drainage for 10 and intrapleural fibrinolytics for 10. The mean duration between the onset of symptom and surgery was 18.4 days. There was neither mortality nor severe complications. The surgical outcomes were class 1 for 28, class 2 for 13, class 3 for 19 and class 4 for 5. There were statistically significant differences between the symptom duration and the classes, and between the operation time and the classes. Conclusion: VATS pleural adhesiolysis and decortication are effective, safe treatments for managing complicated pleural SOL, and an earlier operation is needed for obtaining a better surgical outcome.

• Journal of the Mineralogical Society of Korea
• /
• v.16 no.3
• /
• pp.201-213
• /
• 2003

The adsorption property and ability of domestic zeolites for some heavy metal ions (Ag, Pb, Cr, Cu, Zn, Mn), which may cause a serious environmental problem in industrial wastewater, were evaluated on ore unit through a series of adsorption experiments together with careful examinations of mineral composition and properties of the zeolites. Though the adsorption behavior basically took place in the form of a cation exchange reaction, the higher CEC value does not necessarily to imply the higher adsorption capacity for a specific heavy metal. A general trend of the adsorption selectivity for heavy metals in the zeolites is determined to be as follow: $Ag\geq$Pb>Cr,Cu$\geq$Zn>Mn, but the adsorption properties of heavy metal ions somewhat depend on the species and composition of zeolite. Clinoptilolite tends to adsorb selectively Cu in case of Cr and Cu, whereas heulandite prefers Cr to Cu. A dominant adsorption selectivity of the zeolite ores for Ag and Pb is generally conspicuous regardless of their zeolite species and composition. The zeolite ores exhibit a preferential adsorption especially for $Ag^{+}$ so as not to regenerate when treated with $Na^{+}$ . In the adsorption capacity for heavy meta ions, the zeolites differ in great depending on their species: ferrierite>clinoptilolite>heulandite. Considering the CEC value of mordenite, the mordenite-rich ore appears to be similar to the clinoptilolite ore in the adsorption capacity. The adsorption capacity for heavy metals is not positively proportional to the CEC values of the zeolites measured by the exchange reaction with ammonium ion. In addition, the adsorption capacity roughly tends to depend on the zeolite contents, i.e., the grade of zeolite ore, but the trend is not consistent at all in some ores. These may be caused by the adsorption selectivity for some specific heavy metals, the presence of possible stacking micro-faults and natural cations such as K hardly to exchange in the zeolite. Considering the economic availability and functional effectiveness as natural zeolite resources, clinoptilolite ores could be applicable to utilize the domestic zeolites for the removal of heavy metals.

• The Korean Journal of Nuclear Medicine
• /
• v.37 no.6
• /
• pp.402-417
• /
• 2003

Purpose: To evaluate the use of monoclonal antibody (MoAb) as a carrier of the receptor-binding ligand the receptor mediated uptake into liver and subsequent metabolism of $^{111}In-labeled$ galactosylated MoAb-chelator conjugates were investigated and compared with those of $^{111}In$ labeled MoAb. Materials and Methods : T101 MoAb, $IgG_2$ against human lymphocytic leukemic cell, conjugated with cyclic DTPA dianhydride (DTPA) or 2-p-isothiocyanatobenzyl-6-methyl-DTPA (1B4M) was galactosylated with 2-imino-2-methoxyethyl-1-thio-${\beta}$-D-galactose and then radiolabeled with $^{111}In$. Biodistribution and metabolism study was peformed with two $^{111}In-conjugates$ in mice and rats. Results: $^{111}In-labeled$ T101 and its galactosylated conjugates were taken to the liver by the time, mostly within 10 min. However DTPA conjugate was retained longer in the liver than the 1B4M conjugate (55% vs 20% of injected dose at 44 hr). During this time, the radiornetabolite of DTPA conjugate was excreted similarly into urine (24%) and feces (17%). The radiometabolite of 1B4M was excreted primarily into feces (68%) rather than urine (8%). Size exclusion HPLC analysis of the bile and supernatant of liver homogenate showed two peaks the first (35%) with the retention time (Rt) identical to IgG and the second (65%) with Rt similar to free $^{111}In$ at 3 hr post-injection for the 1B4M conjugate, indicating that the metabolite is rapidly excreted through the biliary system. in contrast to DTPA conjugate, the small $^{111}In-DTPA-like$ metabolite was the major radioindium component (90%) in the liver homogenate as early as 3 hour post-injection, but the cumulative radioindium activity in feces was only 17% at 44 hour, indicating that the metabolite from DTPA conjugate does not clear readily through the biliary tract. Conclusion: The galactosylation of the MoAb conjugates resulted in higher hepatocyte uptake and enhanced metabolism, compared to those without galactosylation. Metabolism of the MoAb-conjugates is different between compounds radiolabled with different chelators due to different characteristics of radiometabolites generated in the liver.

• Journal of Chest Surgery
• /
• v.35 no.4
• /
• pp.296-302
• /
• 2002

The classic approach for esophagectomy is via the combined thoracic and abdominal approach. Controversy exists whether patients with esophageal carcinoma are best managed with Ivor-Lewis esophagectomy(ILO) as combined thoracic and abdominal approach or transhiatal esophagectomy(THO). The THO approach is known to be superior with respect to operative time, severity of leak, morbidity/mortality, and length of stay, but may represent an inferior cancer operation as a result of survival disadvantage due to inadequate mediastinal clearance compared with ILO. Accordingly, we reviewed the results of our esophageal resections to compare these outcome parameters for each operative approach. Material and Method: From January 1993 to July 2001, We performed a retrospective review of all esophagectomies performed at Keimyung University Dongsan ·Medical Center; 27 underwent THO, and 45 underwent ILO Result: The two groups were comparable in terms of age, sex, and stage of the disease. Mean tumor length and mean operative time were 3.81cm and 354 minutes for THO versus 5.31cm and 453 minutes for ILO, respectively (p<0.01 and p<0.001). Respiratory complications were 11.1% for THO versus 35.6% for ILO(p<0.05). Hospital mortality was 11.1% for THO versus 22.2% for ILO. There were no significant differences between THO and ILO with respect to other types of complications, amount of blood transfusion, leak and stricture rates, and hospital stay. Overall long-term survival at 5 years was 37%, respectively. Conclustion: There was no significant difference in long-term survival of patients of both operative approach. ILO had significant difference in respiratory complications associated with hospital mortality. Hence, THO is a valid alternative to ILO for well selected patients. And either approach appears to be acceptable depending on the surgeons, preferences and experiences.

• Journal of Animal Science and Technology
• /
• v.50 no.5
• /
• pp.613-620
• /
• 2008

The genetic parameters used in National Hanwoo Genetic Evaluation(NHGE) were needed to be monitored and updated periodically for accounting any possible changes in population parameters due to selection and environmental changes. Genetic parameters were estimated with single and two-trait models with MTDFREML package using 2,791 carcass records of steers collected from Hanwoo Progeny Test Program(HPTP). Single and two-trait models gave similar parameter estimates for all traits. The heritability estimates from single and two-trait models for carcass weight(CW), dressing percentage(DP), eye muscle area(EMA), back fat thickness(BFT) and marbling score(MS) were 0.30, 0.30, 0.37, 0.44 and 0.44, respectively. The heritability estimates for all the traits except BFT were slightly lower than those used in NHGE but seemed to be within the acceptable ranges. However, further monitoring is needed because the data might not have fully reflected the changes such as carcass grading standards in performance testing program. In order to shift statistical model of NHGE from single trait model to multiple-trait model, the genetic correlations between carcass traits were estimated with pairwise two-trait models. The genetic correlation coefficients between CW and DP, between CW and EMA, between CW and BFT and between CW and MS were 0.44, 0.63, 0.17 and 0.06, respectively. Those between DP and EMA, between DP and BFT and between DP and MS were 0.29, 0.40 and 0.20. Those between EMA and BFT and between EMA and MS were －0.24 and 0.15, respectively. The genetic correlation coefficient between BFT and MS was 0.03.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.11
• /
• pp.1437-1444
• /
• 2000

Objectives : Traditionally intracranial meningiomas are regarded as benign and curable tumors. About half of all intracranial meningiomas locate in the skull base region. However, surgical removal of these tumors may be challenging and require special considerations. Here general aspects of skull base meningiomas including clinical presentation, surgical approaches, complications and their recurrence rate are discussed based on our experiences. Methods : A retrospective analysis of 61 consecutive patients with skull base meningioma among 210 patients of meningioma between 1989 and 1998 were done. Results : There were 41 women and 20 men ranging from 13 to 74 years(mean 52 years). These tumors were divided into seven categories according to location : olfactory groove(n＝9), sphenoid ridge(n＝16), cavernous sinus(n ＝2), tuberculum sellae(n＝8), tentorium(n＝13), cerebellopontine angle(n＝12), and foramen magnum meningiomas (n＝1). Surgical approaches were selected on the basis of the tumor attachment, size and extension on preoperative radiologic findings. Total removal(Simpson grade I and II) was achieved in 50 cases(82%), and subtotal removal (Simpson grade III) in 11 patients(18%). According to WHO classification, there were 52 of cases of benign meningioma( 86%), 6 atypical cases(10%), and 3 malignant cases(5%). The most common postoperative complications were CSF leakage(23.0%) and cranial nerve injury(8.2%). Three patient died related with tumor(one was due to surgical complication and the other two due to recurrence) but three patients died from other systemic causes. Mean follow-up period was 51.7 months after surgery. Recurrence occurred in six patients(10.9%) ; three with tentorial meningioma, two with sphenoid ridge, and one in cerebellopontine angle. Conclusion : With advances in neuroradiology and microsurgical techniques, the surgical outcome of miningiomas has been markedly improved with acceptable morbidity and mortality rates. Overall, our surgical results of skull base meningiomas is comparable to other reports. Therefore, with the appropriate operative strategy and techniques, these tumors can be completely removed and good surgical results can be expected.

• The Korean Journal of Applied Statistics
• /
• v.28 no.6
• /
• pp.1047-1061
• /
• 2015

Stratified random sampling is a powerful sampling strategy to reduce variance of the estimators by incorporating useful auxiliary information to stratify the population. Sample allocation is the one of the important decisions in selecting a stratified random sample. There are two common methods, the proportional allocation and Neyman allocation if we could assume data collection cost for different observation units equal. Theoretically, Neyman allocation considering the size and standard deviation of each stratum, is known to be more effective than proportional allocation which incorporates only stratum size information. However, if the information on the standard deviation is inaccurate, the performance of Neyman allocation is in doubt. It has been pointed out that Neyman allocation is not suitable for multi-purpose sample survey that requires the estimation of several characteristics. In addition to sampling error, non-response error is another factor to evaluate sampling strategy that affects the statistical precision of the estimator. We propose new sample allocation methods using the available information about stratum response rates at the designing stage to improve stratified random sampling. The proposed methods are efficient when response rates differ considerably among strata. In particular, the method using population sizes and response rates improves the Neyman allocation in multi-purpose sample survey.