• Tuberculosis and Respiratory Diseases
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• v.78 no.4
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• pp.341-348
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• 2015

Background: There have been various results from studies concerning the predictors of recurrence in early-stage nonsmall cell lung cancer (NSCLC). Therefore, an accurate assessment is needed to guide effective adjuvant therapy. We investigated the predictors of a recurrence in patients with resected, early-stage NSCLC and the risk factors associated with locoregional or distant recurrence. Methods: This retrospective study was conducted on patients at the Pusan National University Hospital from January 2006 to December 2011. Patients with pathological stages I or II were included in this study, as based on the seventh edition TNM staging system. Multivariate Cox proportional hazard models were used to identify factors associated with recurrence. Results: Two hundred and forty-nine patients were included. Among them, 180 patients were stage I, and 69 were stage II. Overall, by multivariate analysis, the independent factors associated with a 5-year total recurrence were the presence of visceral pleural invasion (VPI) (p=0.018) and maximal standardized uptake values (SUVs) of tumors on positron emission tomography (PET) >4.5 (p=0.037). The VPI was the only independent risk factor associated with both locoregional and distant recurrence, in the analysis of the patterns of tumor recurrence and their risk factors. In the subgroup analysis of stage I patients, three variables (male, VPI and resection margin positive) were significantly associated with a 5-year recurrence. Conclusion: The independent factors associated with postoperative recurrence in early-stage NSCLC were as follows: PET SUV >4.5 and the presence of VPI. For patients with those factors adjuvant therapy should be recommended as a more efficacious treatment.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.5
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• pp.443-448
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• 2015

Obstructive sleep apnea (OSA) is a syndrome characterized by the repetitive episodic collapse of the upper airway. Maxillomandibular advancement surgery is one of the most effective surgical treatment methods in treating obstructive sleep apnea. The advancement of both maxill and mandible can enlarge the cross-sectional areas and volumes of the postero-superior airway. The purpose of this study is to analyze flow patterns in the upper airway before and after maxillomandibular advancement surgery. Here, we analyzed flow phenomena of inspiration and expiration to prevent obstructive sleep apnea patient from happening side effect. Modeling of the upper airway carried out from clinical CT scanned images. We used time-dependent values for boundary condition. CFD analyses were performed and evaluated section of minimum area (SMA), compared with patient inside upper airway before and after maxillomandibular advancement surgery in SMA, and negative pressure effects. The study showed the greatest enlargment of the section of minimum cross-sectional area. Moreover, the velocity and the negative airway pressure were decreased. According to the result of this study, the maxillomandibular advancement surgery stabilizes the airflow in the postero-superior airway of OSA patients.

• Journal of the Korean Solar Energy Society
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• v.23 no.2
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• pp.59-70
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• 2003

A stoichiometric mixture of evaporating materials for $CuGaSe_2$ single crystal thin films was prepared from horizontal electric furnace. Using extrapolation method of X-ray diffraction patterns for the polycrystal $CuGaSe_2$, it was found tetragonal structure whose lattice constant $a_0$ and $c_0$ were $5.615{\AA}$ and $11.025{\AA}$, respectively. To obtain the single crystal thin films, $CuGaSe_2$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperatures were $610^{\circ}C$ and $450^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $CuGaSe_2$ single crystal thin films measured with Hall effect by van der Pauw method are $5.01\times10^{17}cm^{-3}$ and $245cm^2/V{\cdot}s$ at 293K. respectively. The temperature dependence of the energy band gap of the $CuGaSe_2$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g$(T)=1.7998 eV-($8.7489\times10^{-4}$ eV/K)$T^2$/(T+335K). After the as-grown $CuGaSe_2$ single crystal thin films was annealed in Cu-, Se-, and Ga-atmospheres, the origin of point defects of $CuGaSe_2$ single crystal thin films has been investigated by the photoluminescence(PL) at 10 K. The native defects of $V_{CU},\;V_{Se},\;Cu_{int}$ and $Se_{int}$ obtained by PL measurements were classified as a donors or acceptors type. And we concluded that the heat-treatment in the Cu-atmosphere converted $CuGaSe_2$ single crystal thin films to an optical n-type. Also, we confirmed that Ga in $CuGaSe_2$/GaAs did not form the native defects because Ga in $CuGaSe_2$ single crystal thin films existed in the form of stable bonds.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.4
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• pp.232-241
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• 2020

Purpose: This study investigated the complications and patterns of implants that confronted with the extruded natural teeth. Materials and Methods: Among patients who received implant treatment between 2006 and 2018 at Chosun University Dental Hospital, only implants that had a maintenance period of at least 5 years and that both implants and confronting natural teeth could be measured and compared on a radiograph were selected. They were divided into two groups. Group 1, experimental group consisted of Implants confronting the extruded natural posterior teeth (n = 167: maxilla (Group 1max) = 92, mandible (Group 1man) = 75) and Group 2, control group consisted of Implants confronting the normal natural posterior teeth (n = 656: maxilla (Group 2max) = 272, mandible (Group 2man) = 384). Results: The incidence of complications between Group 1 and Group 2 was statistically significant. In particular, there was a statistically significant difference between the frequency of marginal bone loss and the amount of marginal bone loss. Conclusion: The extruded natural tooth may cause more frequent complications including bone resorption in the opposing implant.

• Journal of Physiology & Pathology in Korean Medicine
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• v.35 no.6
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• pp.211-218
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• 2021

In order to increase the clinical value of an identification of patterns according to the eight principles (IPEP) in Korean medicine practice, The research on the Clinical Practice Guideline (CPG) of IPEP should comprehend the situation of clinical usage of IPEP practiced by Korean medicine doctors at first. Google survey form were emailed to Korean Medicine doctors registered in the Association of Korean Medicine on 04/15/2021 and the survey was closed at 04/22/2021. Data of 505 answered cases were analyzed by Frequency analysis, Chi-Square analysis, correlation analysis for understanding differences by groups. Out of 505 respondents, 57.6% have answered that they are using IPEP. It means that 42.4% of KM doctors don't use in the medical practice reversely in spite of fundamental diagnostic theory. The 64.7% respondents of no using IPEP presented their opinion about the theoretical problem that it is difficult to use because the concept of IPEP is ambiguous. And next, the 52.1% of the respondents expressed that there is no objective tools to measure and record the IPEP evidences in actual implementation. And 49.6% of the respondents also suggested that it is hard to trust and use IPEP similar to the previous comment. Even about 50% of the respondents are carrying out diagnosis and treatment using IPEP, it showed that there were several unsolved problems such as lack of understanding and practical tools or objective indicators for diagnosis of IPEP. Through the above results, the concept, usage, measurement requirements with indices and discriminant logic of IPEP were manifested as the main hopes of attending members of Korean medicine in the survey, so the IPEP CPG should make clear about these difficult but necessary assignment in the near future.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.3
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• pp.179-191
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• 2022

Carbapenem-resistant Enterobacteriaceae (CRE) poses an increasing public health threat and has limited treatment options with high associated mortality. Genotypes of carbapenemase that threaten public health (bla_KPC, bla_NDM, bla_IMP, and bla_VIM) and bla_OXA-48-like genes were detected by phenotypic and molecular diagnosis, and related gene distribution patterns were investigated. Phenotypic testing using the modified Hodge test confirmed positivity in all 41 strains examined, and carbapenemase inhibitory testing using meropenem+phenyl boronic acid or meropenem+EDTA confirmed positivity in 18 and 8 strains, respectively. Polymerase chain reaction revealed the presence of amplification products in 28 strains of bla_KPC, 25 strains of bla_NDM, 5 strains of bla_IMP, 1 strain of bla_VIM, and 13 bla_OXA-48-like strains. In addition, 7 strains of bla_KPC+bla_NDM, 1 strain of bla_KPC+bla_IMP, 1 strain of bla_NDM+bla_OXA-48-like, 1 strain of bla_NDM+bla_VIM, 4 strains of bla_KPC+bla_NDM+bla_IMP, and 4 strains of bla_KPC+bla_NDM+bla_OXA-48-like were identified. Melting curve analysis using real-time PCR was wholly consistent with PCR results. The study shows genetic identification of highly specific CRE by real-time PCR could be used to provide early diagnoses and infection control, improve surveillance, and prevent the transmission of CRE.

• International Journal of Stem Cells
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• v.15 no.2
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• pp.155-163
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• 2022

Background and Objectives: Mesenchymal stem cells (MSCs) have immunomodulatory function and participate in the pathogenesis of many immunoregulation-related diseases, including psoriasis. Previously, we found that MSCs from psoriatic lesions overexpress the proinflammatory microRNA, miR-155 and exhibit a decreased immunosuppressive capacity. But the origin of these aberrant characteristics is still not clear. To investigate whether inflammatory cytokines in serum and peripheral blood mononuclear cells (PBMCs) from psoriatic patients can regulate the expression patterns of immunoregulation-related cytokines and the immunoregulation function of MSCs. Methods and Results: Normal dermal mesenchymal stem cells (nDMSCs) were treated with serum or PBMCs derived from patients with psoriasis or healthy donors. Expression of miR-155 and immunoregulation-related genes in each MSCs were measured using real-time PCR or western-blot. Meanwhile, the immunosuppressive capacity of DMSCs was evaluated by its inhibitory ability on proliferation of activated PBMCs. Compared to control serum, psoriatic serum significantly increased the expression levels of miR-155 (27.19±2.40 vs. 3.51±1.19, p<0.001), while decreased TAB₂ expression (0.28±0.04 vs. 0.72±0.20, p<0.01) in DMSCs. Expression levels of immunoregulation-related genes such as PGE₂, IL-10, and TLR4 were also markedly down-regulated following the psoriatic serum treatment. Those DMSCs treated with healthy serum could inhibit PBMC proliferation, while those psoriatic serum-treated DMSCs could not inhibit PBMC proliferation effectively. Conclusions: Psoriatic serum up-regulate the expression of miR-155, down-regulate the expression of immunoregulation-related genes (PGE₂, IL-10, and TLR4) in DMSCs, and along with the inhibition of the immunosuppressive function of MSCs.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.12
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• pp.974-978
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• 2012

The effect of Cu coating on the sensing properties of nano $SnO_2:Cu$ based sensors for the $CH_4$, $CH_3CH_2CH_3$ gas was studied. This work was focussed on investigating the change of sensitivity of nano $SnO_2:Cu$ based sensors for $CH_4$, $CH_3CH_2CH_3$ gas by Cu coating. Nano sized $SnO_2$ powders were prepared by solution reduction method using stannous chloride($SnCl_2{\cdot}2H_2O$), hydrazine($N_2H_2$) and NaOH and subsequent heat treatment. XRD patterns showed that nano $SnO_2$ powders with rutile structure were grown with (110), (101), (211) dominant peak. The particle size of nano $SnO_2:Cu$ powders at 8 wt% Cu was about 50 nm. $SnO_2$ particles were found to contain many pores, according to SEM analysis. The sensitivity of nano $SnO_2:Cu$ based sensors was measured for 5 ppm $CH_4$ gas and $CH_3CH_2CH_3$ gas at room temperature by comparing the resistance in air with that in target gases. The sensitivity for both $CH_4$ and $CH_3CH_2CH_3$ gases was improved by Cu coating on the nano $SnO_2$ surface. The response time and recovery time of the $SnO_2:Cu$ gas sensors for the $CH_4$ and $CH_3CH_2CH_3$ gases were 18~20 seconds, and 13~15 seconds, respectively.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.4
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• pp.217-223
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• 2004

Objective: To evaluate the effects of recombinant FSH (rFSH) and urinary FSH (uFSH) on the gene expressions of human endometrial stromal cells in vitro. Methods: Endometrial tissue was obtained from a pre-menopausal women undergoing hysterectomy. Primary endometrial stromal cells were isolated and in vitro cultured with FBS-free DMEM/F-12 containing 0, 10, 100, and 1, 000 mIU/ml of rFSH and uFSH for 48 hours, respectively. Total RNA was extracted from the cultured cells and subjected to real time RT-PCR for the quantitative analysis of progesterone receptor (PR), estrogen receptor $\alpha/\beta$ (ER-$\alpha/\beta$), cyclooxygenase 2 (Cox-2), leukemia inhibitory factor (LIF), homeobox A10-1 and -2 (HoxA10-1/-2). Results: Both hormone treatments slightly increased (< 3 folds) the expressions of PR, ER-$\beta$ and HoxA10-1/-2 gene. However, ER-$\alpha$ expression was increased up to five folds by treatments of both FSH for 48 hours. The LIF expression by the 10 mIU/ml of uFSH for 12 hours was significantly higher than that of rFSH (p<0.01). After 24 hours treatment of two kinds of hormones, the expression patterns of LIF were similar. The 100 and 1, 000 mIU/ml of rFSH induced significantly higher amount of Cox-2 expression than those of uFSH, respectively (p<0.05). Conclusion: This study represents no adversely effect of exogeneous gonadotropins, rFSH and uFSH, on the expression of implantation related genes. We suggest that rFSH is applicable for the assisted reproductive technology without any concern on the endometrial receptivity.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.5
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• pp.507-524
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• 2002

Load transfer of implant overdenture varies depending on anchorage systems that are the design of the superstructure and substructure and the choice of attachment. Overload by using improper anchorage system not only will cause fracture of the framework or screw but also may cause failure of osseointegration. Choosing anchorage system in making prosthesis, therefore, can be considered to be one of the most important factors that affect long-term success of implant treatment. In this study, in order to determine the effect of anchorage systems on load transfer in mandibular implant overdenture in which 4 implants were placed in the interforaminal region, patterns of stress distribution in implant supporting bone in case of unilateral vertical loading on mandibular left first molar were compared each other according to various types of anchorage system using three-dimensional photoelastic stress analysis. The five photoelastic overdenture models utilizing Hader bar without cantilever using clips(type 1), cantilevered Hader bar using clips(type 2), cantilevered Hader bar with milled surface using clips(type 3), cantilevered milled-bar using swivel-latchs and frictional pins(type 4), and Hader bar using clip and ERA attachments(type 5), and one cantilevered fixed-detachable prosthesis(type 6) model as control were fabricated. The following conclusions were drawn within the limitations of this study, 1. In all experimental models. the highest stress was concentrated on the most distal implant supporting bone on loaded side. 2. Maximum fringe orders on ipsilateral distal implant supporting bone in a ascending order is as follows: type 5, type 1, type 4, type 2 and type 3, and type 6. 3. Regardless of anchorage systems. more or less stresses were generated on the residual ridge under distal extension base of all overdenture models. To summarize the above mentioned results, in case of the patients with unfavorable biomechanical conditions such as not sufficient number of supporting implants, short length of the implant and unfavorable antero-posterior spread. selecting resilient type attachment or minimizing distal cantilever bar is considered to be appropriate methods to prevent overloading on implants by reducing cantilever effect and gaining more support from the distal residual ridge.