• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.202-210
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• 2020

This study investigated the optimal levels of stand density control considering the stability of Larix kaempferi stands. A stand density management diagram was developed from 259 sample plots. Based on these data, we determined an optimal level of the stand density control by identifying the relationship between the relative yield index (Ry) and height-to-diameter ratio. The estimated r-square (R²) of the stand density management diagram is 0.600. The analysis of the relationship between Ry and the slender tree incidence showed that when the stand density exceeded a certain threshold and the ratio of slender trees rapidly increased. The critical value of Ry was 0.63. The results of this study are expected to contribute to the establishment of stand management strategies that can reduce damage from natural causes, such as wind and snow, and to develop stand practice systems for the improved productivity of commercial forests.

• Pediatric Infection and Vaccine
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• v.18 no.1
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• pp.1-14
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• 2011

Tuberculosis is a disease with high morbidity and mortality in children worldwide. Despite the decrease in the incidence of tuberculosis in Korea, more than 30,000 new patients are diagnosed each year. Active tuberculosis is less frequent in children compared to adults but the risk of miliary tuberculosis and CNS tuberculosis is much higher. The diagnosis of tuberculosis in children and adolescents is difficult due to the nonspecific symptoms upon presentation. Diagnostic work up is based on the confirmation of tuberculosis infection by tuberculin skin test, abnormal radiologic findings, and contact with an adult with active tuberculosis. Anti-tuberculosis medications are prescribed according to the drug susceptibility of the index patient. Latent tuberculosis infection plays an important role in adult tuberculosis by reactivation. Thus, it is critical to accurately diagnose latent tuberculosis in children to prevent reactivation in adulthood. Korean guidelines for diagnosis and treatment of tuberculosis in children and adolescents provide evidence based recommendations in the optimal diagnosis and treatment for active and latent tuberculosis in children and adolescents based on the current Korean situation.

• Journal of Microbiology and Biotechnology
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• v.30 no.6
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• pp.856-867
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• 2020

Vibrio parahaemolyticus is a major gastroenteritis-causing pathogen in many Asian countries. Antimicrobial resistance in V. parahaemolyticus has been recognized as a critical threat to food safety. In this study, we determined the prevalence and incidence of antimicrobial resistance in V. parahaemolyticus in the southern Fujian coast, China. A total of 62 isolates were confirmed in retail aquatic products from June to October of 2018. The serotype O3:K6 strains, the virulence genes tdh and trh, antibiotic susceptibility and molecular typing were investigated. Then plasmid profiling analysis and curing experiment were performed for multidrug-resistant strains. The results showed that the total occurrence of V. parahaemolyticus was 31% out of 200 samples. Five strains (8.1%) out of 62 isolates were identified as the V. parahaemolyticus O3:K6 pandemic clone. A large majority of isolates exhibited higher resistance to penicillin (77.4%), oxacillin (71%), ampicillin (66.1%) and vancomycin (59.7%). Seventy-one percent (44/62) of the isolates exhibited multiple antimicrobial resistance. All 62 isolates were grouped into 7 clusters by randomly amplified polymorphic DNA, and most of the isolates (80.6%) were distributed within cluster A. Plasmids were detected in approximately 75% of the isolates, and seven different profiles were observed. Seventy-six percent (25/33) of the isolates carrying the plasmids were eliminated by 0.006% SDS incubated at 42℃, a sublethal condition. The occurrence of multidrug-resistant strains could be an indication of the excessive use of antibiotics in aquaculture farming. The rational use of antimicrobial agents and the surveillance of antibiotic administration may reduce the acquisition of resistance by microorganisms in aquatic ecosystems.

• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.152-161
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• 2013

This study attempted to test the causal effect of structural characteristics of metropolitan neighborhoods on crime, based on the ecological model of crime explanation. To this end, a Negative Binomial Regression analysis was performed for Seoul's 424 Dong Districts. Results showed that the incidence of homicide increases as much as the scales of economic disadvantage, family disruption, and commercial land use go worse. It suggested that family integrity is one of the most strong and consistent factors that could deter crime in neighborhood's contexts. Economic disadvantage and commercial land use were also critical targets as crime-generating factors. Reasoning with the results of past studies implied that neighborhood-specific approaches need to be developed for effective crime prevention. Although a few limitations could raise a caveat against such interpretation of the results, the value of this research would not be simply denied as the first attempt to utilize all Dong districts of Seoul. It is expected that this study contributes to activating Dong level research and developing effective crime control policy.

• Journal of Microbiology and Biotechnology
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• v.24 no.8
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• pp.1143-1147
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• 2014

Human papillomavirus (HPV) infection is considered to play a critical role in the development of cervical carcinoma, which is the third most common cancer among Korean females. Here, we performed a baseline study of HPV infection and genotyping using an HPV DNA chip, which is a type of oligonucleotide microarray. A total of 6,855 cervical swab specimens from 5,494 women attending Dankook University Hospital Health Improvement Center in Cheonan, Korea between 2006 and 2012, originally collected for HPV infection screening, were genotyped for HPV. The extracted DNA from the cervical specimens was investigated by an HPV DNA chip designed to detect 41 different HPV types. HPV was identified as positive in 1,143 (16.7%) of the 6,855 samples. The most frequently detected HPV genotypes were HPV types 16, 53, 56, 58, 39, 52, 70, 84, 68, 62, 35, 54, 81, 18, and 30, in descending order of incidence. The proportions of single and multiple HPV infections in the HPV-positive specimens were 78.1% and 21.9%, respectively. The average age of HPV-positive patients was 39.9 years, with the positive rate of HPV being the highest in the 10-29 age group (20.6%). We report here on the prevalence and distribution of 41 different genotypes of HPV according to age among women in Cheonan, Korea. These data may be of use as baseline data for the assessment of public health-related issues and for the development of area-specific HPV vaccines.

• The Korean Journal of Pain
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• v.31 no.3
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• pp.155-173
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• 2018

Chronic postsurgical pain (CPSP) is an unwanted adverse event in any operation. It leads to functional limitations and psychological trauma for patients, and leaves the operative team with feelings of failure and humiliation. Therefore, it is crucial that preventive strategies for CPSP are considered in high-risk operations. Various techniques have been implemented to reduce the risk with variable success. Identifying the risk factors for each patient and applying a timely preventive strategy may help patients avoid the distress of chronic pain. The preventive strategies include modification of the surgical technique, good pain control throughout the perioperative period, and preoperative psychological intervention focusing on the psychosocial and cognitive risk factors. Appropriate management of CPSP patients is also necessary to reduce their suffering. CPSP usually has a neuropathic pain component; therefore, the current recommendations are based on data on chronic neuropathic pain. Hence, voltage-dependent calcium channel antagonists, antidepressants, topical lidocaine and topical capsaicin are the main pharmacological treatments. Paracetamol, NSAIDs and weak opioids can be used according to symptom severity, but strong opioids should be used with great caution and are not recommended. Other drugs that may be helpful are ketamine, clonidine, and intravenous lidocaine infusion. For patients with failed pharmacological treatment, consideration should be given to pain interventions; examples include transcutaneous electrical nerve stimulation, botulinum toxin injections, pulsed radiofrequency, nerve blocks, nerve ablation, neuromodulation and surgical management. Physical therapy, cognitive behavioral therapy and lifestyle modifications are also useful for relieving the pain and distress experienced by CPSP patients.

• Journal of Nutrition and Health
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• v.49 no.2
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• pp.72-79
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• 2016

Purpose: The initiation of mandatory folic acid fortification using pteroylmonoglutamic acid (PteGlu) has reduced the rate of congenital malformations. However, it also appears to be responsible for several adverse effects, including increased cancer incidence. This may be related to physicho-chemical characteristics of PteGlu. This study examines the potential effect of high concentrations of PteGlu on a population subjected to mandatory folic acid fortification using an in vitro model. Methods: Caco-2 (colorectal cancer) and MCF7 (breast cancer) cell lines were cultured at 6 different PteGlu concentrations (0, 0.1, 1, 50, 250, and $500{\mu}g/ml$) for 6 days. Cell growth was determined using thiazolyl blue tetrazolium bromide assay. The genotype of dihydrofolate reductase 19bp deletion/insertion (DHFR 19-del) was also scored in cell lines using a restriction fragment length polymorphism technique to examine whether genetic variations may factor in cell proliferation. Results: PteGlu exhibited differential growth promoting properties between cell lines. Caco-2 cells did not show a significant growth difference at low concentrations compared to control, however, at higher concentrations, the growth showed a contrasting trend in the early experimental period, while MCF7 showed enhanced cell growth at all concentrations. The DHFR 19-del genotype differed in the two cell lines. Conclusions: Altered response to PteGlu by Caco-2 and MCF7 may reflect a tissue specific disease aetiology or genotype specific differential enzyme activity, for example by DHFR, to critical levels of PteGlu. As folic acid fortification is a blanket intervention, and DHFR and other enzyme activities vary between individuals, PteGlu intake may have an as yet undefined effect on health. These findings may be relevant when considering mandatory folic acid fortification for disease prevention.

• Journal of Korean Neurosurgical Society
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• v.48 no.3
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• pp.244-250
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• 2010

Objective : Adequate management of increased intracranial pressure (ICP) is critical in patients with traumatic brain injury (TBI), and decompressive craniectomy is widely used to treat refractory increased ICP. The authors reviewed and analyzed complications following decompressive craniectomy for the management of TBI. Methods : A total of 89 consecutive patients who underwent decompressive craniectomy for TBI between February 2004 and February 2009 were reviewed retrospectively. Incidence rates of complications secondary to decompressive craniectomy were determined, and analyses were performed to identify clinical factors associated with the development of complications and the poor outcome. Results : Complications secondary to decompressive craniectomy occurred in 48 of the 89 (53.9%) patients. Furthermore, these complications occurred in a sequential fashion at specific times after surgical intervention; cerebral contusion expansion ($2.2{\pm}1.2$ days), newly appearing subdural or epidural hematoma contralateral to the craniectomy defect ($1.5{\pm}0.9$ days), epilepsy ($2.7{\pm}1.5$ days), cerebrospinal fluid leakage through the scalp incision ($7.0{\pm}4.2$ days), and external cerebral herniation ($5.5{\pm}3.3$ days). Subdural effusion ($10.8{\pm}5.2$ days) and postoperative infection ($9.8{\pm}3.1$ days) developed between one and four weeks postoperatively. Trephined and post-traumatic hydrocephalus syndromes developed after one month postoperatively (at $79.5{\pm}23.6$ and $49.2{\pm}14.1$ days, respectively). Conclusion : A poor GCS score ($\leq$ 8) and an age of $\geq$ 65 were found to be related to the occurrence of one of the above-mentioned complications. These results should help neurosurgeons anticipate these complications, to adopt management strategies that reduce the risks of complications, and to improve clinical outcomes.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.165-171
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• 2016

Platycodon grandiflorum and Codonopsis lanceolata have been considered as cash vegetables and alternative medicine plants in Korea. In a previous survey from 1998 to 2010, repeated cultivation of the plant increased root rot disease incidence and severity. The disease has been recognized as critically limiting factor for crop production. However, control method has not been established for the disease of P. grandiflorum and C. lanceolata. In this study, control efficacy of Tebuconazole EC, Trifloxystroim SC and grapefriut extract was evaluated on the root rot disease of these plants in two different field conditions. Three of different fungicide were non critical effect to the disease severity and the control value, but grapefriut seed extract (GSE) was more ability to control the disease in C. lanceolata. In most things, soil drainage was the most important to decrease the disease severity and to improve the control value.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.11.2-11.2
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• 2011

Polymer based organic photovoltaics have attracted a great deal of attention due to the potential cost-effectiveness of light-weight and flexible solar cells. However, most BHJ polymer solar cells are not thermally stable as subsequent exposure to heat drives further development of the morphology towards a state of macrophase separation in the micrometer scale. Here we would like to show three different approaches for developing new electroactive polymers to improve the thermal stability of the BHJ solar cells, which is a critical problem for the commercialization of these solar cells. For one of the examples, we report a new series of functionalized polythiophene (PT-x) copolymers for use in solution processed organic photovoltaics (OPVs). PT-x copolymers were synthesized from two different monomers, where the ratio of the monomers was carefully controlled to achieve a UV photo-crosslinkable layer while leaving the ${\pi}-{\pi}$ stacking feature of conjugated polymers unchanged. The crosslinking stabilizes PT-x/PCBM blend morphology preventing the macro phase separation between two components, which lead to OPVs with remarkably enhanced thermal stability. The drastic improvement in thermal stabilities is further characterized by microscopy as well as grazing incidence X-ray scattering (GIXS). In the second part of talk, we will discuss the use of block copolymers as active materials for WOLEDs in which phosphorescent emitter isolation can be achieved. We have exploited the use of triarylamine (TPA) oxadiazole (OXA) diblock copolymers (TPA-b-OXA), which have been used as host materials due to their high triplet energy and charge-transport properties enabling a balance of holes and electrons. Organization of phosphorescent domains in TPA-b-OXA block copolymers is demonstrated to yield dual emission for white electroluminescence. Our approach minimizes energy transfer between two colored species by site isolation through morphology control, allowing higher loading concentration of red emitters with improved device performance. Furthermore, by varying the molecular weight of TPA-b-OXA and the ratio of blue to red emitters, we have investigated the effect of domain spacing on the electroluminescence spectrum and device performance.