• Title/Summary/Keyword: 사멸률

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Empirical Research on the Death of Foreign-invested Companies (외국인 투자기업의 사멸에 관한 실증연구)

  • Seong, Kil-Yong
    • The Journal of the Korea Contents Association
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    • v.22 no.6
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    • pp.692-700
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    • 2022
  • This study was conducted to analyze firms' death rate and impact factors on the death of Foreign-invested Companies in Korea which is between 20013 and 2017. Cox Proportional Hazard Model took to conduct on the death impact factors, such as 2 characteristics factors of the firm, and 4 financial characteristics variables, variables, and 4 profitability factors. As a result of the impact factors of Foreign-invested Companies' death the Labour(NE) variables of characteristics firm had negative effects. And the Debt(LB), Operating Profit (OP), and Sales Profit (SP) of the financial characteristics had a negative effect. Other factors did not produce significant results. As a result of an empirically comparative analysis of the mortality rate of foreign-invested companies by the Kaplan-Meier method, it was analyzed that fully owned companies and large enterprises had lower extinction risk and greater sustainable management potential than joint ventures or SMEs.

Comparative Characterization on Bacterial Disinfection Using Trichloroisocyanuric Acid, Bromochlorodimethylhydantoin, and Calcium Hypochlorite (삼염화이소시아눌산, 브룸염화히단토인, 및 칼슘하이포클로라이트의 농도 및 접촉시간에 따른 미생물 사멸특성)

  • Oh, Se-Hyun;Yoo, Hyun-Duk;Lee, Han-Na;Kim, Eung-Soo
    • Microbiology and Biotechnology Letters
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    • v.35 no.4
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    • pp.334-338
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    • 2007
  • The disinfection effects of trichloroisocyanuric acid (TICA), calcium hypochlorite (CH), and Bromochlorodimethylhydantoin (BCDMH) on various bacteria in aqueous suspension were comparatively characterized at various concentrations and exposure times of each disinfectant. When various bacteria cells ($10^8\;CFU/ml$) including Escherichia coli, Pseudomonas aeroginosa, Enterococcus faecalis, Bacillus cereus, Legionella pneumophila, and Staphylococcus aureus were exposed with a solution containing 8 ppm each of TICA, a 99% of the initial cells were killed in 60 sec, 368 sec, 372 sec, 506 sec, 812 sec, and 909 sec, respectively. In addition, the minimum exposure time required to kill 99% of E. coli ($10^8\;CFU/ml$) with 8 ppm of each TICA, BCDMH and CH was measured at 60 sec, 114 sec, and 7,100 sec, respectively. These comparative studies demonstrate that disinfection efficacy is highly variable depending on microbial species as well as disinfectant type, concentration, and exposure time.

Disinfection Effect of Trichloroisocyanuric Acid and Calcium Hypochlorite on Escherichia coli in Water (Trichloroisocyanuric Acid와 Calcium Hypochlorite의 농도 및 접촉시간에 따른 대장균의 사멸특성)

  • 김응수;강자경;박현주
    • KSBB Journal
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    • v.17 no.3
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    • pp.314-316
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    • 2002
  • The disinfection effects of trichloroisocyanuric acid (TICA) and calcium hypochlorite on E. coli in aqueous suspension were comparatively characterized at various concentrations and exposure times of each disinfectant. When the E. coli ($10^{7}$ CFU/mL) cells were exposed with a solution containing 12 ppm each of TICA and calcium hypochlorite, a 90% of the initial cells were killed in 4 sec and 390 sec, respectively. In addition, calcium hypochlorite lost its disinfection effect in about 1 hr exposure under the sun light, whereas TICA maintained its disinfection effect up to 6 hrs under the same condition. These comparative studies demonstrate that TICA is a more effective and stable disinfectant than calcium hypochlorite to sterilize E. coli in aqueous suspension.

Neutrophil Apoptosis and $H_2O_2$ Release by LPS in Diabetics (내독소로 자극된 당뇨환자의 중성구에서 기획성 세포사멸과 과산화수소 분비능)

  • Seo, Ki Hyun;Na, Joo Ock;Moon, Seung Hyug;Uh, Soo Taek;Kim, Yong Hoon;Park, Choon Sik
    • Tuberculosis and Respiratory Diseases
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    • v.57 no.3
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    • pp.250-256
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    • 2004
  • Background : Bacterial infections in diabetic patients are an important cause of increased morbidity and mortality. It has been reported that bacterial infections in diabetics showed more impaired PMN functions such as reduced PMN respiratory burst and decreased microbicidal activity in inflammed tissues. Also, apoptosis(programmed cell death) is postulated to be a key mechanism for neutrophil elimination. It is very important that PMN apoptosis keeps the balance from an area of inflammation. Actuallly, as little was known about PMN apoptosis and respiratory burst in diabetes, we investigated PMN apoptosis and hydrogen peroxide production after endotoxin exposure. Methods : Peripheral venous blood samples were collected by routine venipuncture from healthy volunteers and diabetics to harvest neutrophils. We respectively measured the PMN apoptosis, the production of hydrogen peroxide, and the cell viability. Results : Normal neutrophils showed a tendency to decreased apoptosis after endotoxin treatment. In patients with diabetes, PMN apoptosis was significantly decreased compared with healthy controls. In addition, the LPS-induced neutrophils in diabetics demonstrated more decreased apoptosis. However, the production of hydrogen peroxide was not different between groups. Conclusion : These observations suggest that the decreased PMN apoptosis in diabetics with endotoxin exposure may also affect the increased susceptibility and severity of infections.

Effect of Apoptosis on Porcine Parthenotes Development in vitro (돼지 단위발생 배아의 발달과정에서 세포사멸에 관한 연구)

  • Lee, Jae-Dal
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.8
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    • pp.3843-3849
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    • 2013
  • This study was conducted to determine the effects of fetal bovine serum (FBS), bovine serum albumin (BSA) and epidermal growth factor (EGF) on blastocoel formation, total cell number, apoptosis and apoptosis-related gene expression of porcine diploid parthenotes developing in vitro. The addition of 0.4% BSA to the culture medium enhanced the development of 2-cell stage parthenotes to the blastocysts stage (p<0.01). Treatment of FBS reduced cell numbers of blastocysts (p<0.01) and increased the percentage of apoptosis in blastocysts (p<0.001). However, BSA increased cell numbers, only in the presence of EGF reverse-transcriptase polymerase chain reaction revealed that EGF enhanced the mRNA expression of Bcl-xL in the presence of 0.4% BSA but BSA and EGF alone had no effect. However, Treatment of FBS reduced Bcl-xL mRNA expression (p<0.05) and enhanced Bak expression. This result suggests that apoptosis related gene expression is significantly affected by supplements, which may result in alteration of apoptosis and embryo viability of porcine embryos developing in vitro.

A Study on the Measurement of the Pollution Level of Bacteria and Disinfection of Table and IP Cassette (촬영 테이블과 IP Cassette의 세균 오염도 측정 및 소독에 관한 연구)

  • Bae, Seok-Hwan;Lee, Moo-Sik;Lim, Chang-Seon;Kim, Gha-Jung
    • Journal of radiological science and technology
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    • v.31 no.3
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    • pp.229-237
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    • 2008
  • Purpose : For the number of microbes and the pollution level of bacteriology of IP Cassette and Table by laboratories, after identifying the bacteria before and after using alcohol and tissue including disinfectant and statistically testing, this research was intended to provide the basic data for the prevention and the right disinfection guideline for infection management of hospitals in diagnostic radiology. Subject and Method : The subject of this research was the general room of diagnostic radiology of a university hospital in Daejeon City. The research was conducted from Apr 5 to Apr 12, 2007. The number of microbes and the pollution level of bacteriology of IP Cassette and Table by laboratories were tested before and after using alcohol and tissue for disinfection including disinfectant. In order to collect specimens exactly, they were collected with the nurse who specialized in infection management of the hospital, and statistical processing was done with SPSS V13.0. To compare the results before and after using alcohol and tissue, T-test was implemented, and post-hoc test was conducted. Results : Bacteria were detected in 19 cases of 24 subjects(79.2%), however, they were not detected in 5 cases(20.8%). 7kinds of bacteria were detected as isolated bacteria, of which Methicillin Resistant coagulase-negative Staphylococci(MRCNS) were detected in 15 cases(62.5%), which was most, Methicillin Resistant Staphylococcus Aureus(MRSA) in 6 cases(16.7%), Enterococcus Faecium(EFM) in 5 cases(20.8%), Acinetobacter baumannii(ABA) in 2 cases(8.3%), and Bacillus sp, Coagulase-negative Staphylococci(CNS), and Enterococcus sp(ENT) in 1 case, respectively(4.2%). In all bacteria except ABA, Gram positive bacillia were detected in 30 cases(97%), and Gram negative bacilli were detected only in 1 case(3%). As for the kinds of bacteria and the number of groups before and after using 70% Alcohol by Groups, when the bacteria were identified after disinfecting IP Cassette and Table with 70% Alcohol, all the bacteria became extinct in both IP Cassette and Table Group(100%). As for the kinds and number of bacteria before and after using Tissue Cleaner by Groups, the bacteria in Tissue Cleaner Group became completely extinct only in 10 Groups(71.2%), and in 4 Groups, there was much decrease in bacteria, however, they were still detected. The extinction rate of all the bacteria was 91.5%. That is, though the other bacteria became extinct(100%), that of MRCNS bacteria was lowest(83.6%), followed by MRSA(95%). Conclusion : As a result of comparing the mean of the bacteria which were detected before and after using 70% Alcohol and Tissue Cleaner, there was statistically significant in the significant level of 5% in both of them.

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Effects of Fermented Achyranthes japonica Nakai, Angelica gigas Nakai, and Eucommia ulmoides Oliver Extracts on Regulation of Apoptosis in Articular Chondrocytes (Primary Chondrocytes에서 발효우슬, 당귀, 두충 복합물의 세포사멸 조절 효과)

  • Dakyung Kim;Wonhee Jo;Minhee Lee;Hyun Cheol Jeong;Sung-Jin Lee;Seunghun Lee;Jeongmin Lee
    • Journal of Applied Biological Chemistry
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    • v.66
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    • pp.7-14
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    • 2023
  • The effects of fermented Achyranthes japonica Nakai, Angelica gigas Nakai, and Eucommia ulmoides Oliver extracts (FAAE) on regulation of inflammation and apoptosis were investigated in primary cultured rat cartilage cells. To identify the protective effects of FAAE against H2O2, cell survival was measured by MTT assay. Smad3, Collagen type I, MMP3, and MMP13 were measured by real-timpe PCR and westernbot and the inflammatory (NF-κB pathway, COX-2, iNOS) factors were determined by western blot. The apoptosis related factors (JNK, c-Fos, c-Jun, caspase 3, Bax, and Bcl-2) were determined by western blot. FAAE significantly increased the follwing: H2O2 treated cell survival, mRNA and protein expression of Smad 3, collagen type I. In addition, FAAE significantly decreased the protein expression of inflammatory and apoptosis related factors. This study suggests that FAAE have a protection effect of chondrocytes through inhibition of inflammation and apoptosis. Thus, FAAE is a therapeutic potential food componet in osteoarthritis.

Anti-cancer effects of kelp extract in mouse melanoma B16-F0 cell line through apoptosis (마우스 흑색종 세포주 B16-F0에서 다시마 추출물의 세포사멸을 통한 항암 효과)

  • Lee, Seong-Uk;Kim, Yoon Hee
    • Korean Journal of Food Science and Technology
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    • v.54 no.2
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    • pp.134-140
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    • 2022
  • Kelp belongs to the brown algae family and has been reported to exert anti-cancer effects on some cancer types, however studies have not been reported on the anti-cancer effects of kelp extracts on melanoma. In this study, the anti-cancer effects of kelp extract in B16-F0 cells were investigated, and the underlying molecular mechanisms were assessed. Kelp extract was found to inhibit the proliferation of B16-F0 cells, induce cytotoxicity, inhibit cell colony formation, and induce DNA fragmentation and apoptosis. The molecular mechanism was found to involve kelp extract increasing the expression of cytochrome-c and activated caspase-9 in the intrinsic apoptotic pathway. In addition, kelp extract upregulated the expression of Fas-associated protein with death domain and activated caspase-8 in the extrinsic apoptosis pathway. Activation of caspase-9 and caspase-8 by kelp extract induced activation of caspase-3 and cleaved poly adenosine diphosphate-ribose polymerase, consequently inducing apoptosis. These data suggest that kelp extract represents a potential therapeutic agent for melanoma.

저온 플라즈마를 이용한 바이오 메디컬 분야에의 응용

  • Park, Gan-Yeong;Kim, Gon-Jun;Lee, Hyeon-U;Yun, Ji-In;Sim, Jae-Yun;Kim, Gyeong-Tae;Kim, Gyu-Cheon;Lee, Jae-Gu
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.41-41
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    • 2010
  • 상온에 준하는 저온의 플라즈마를 발생시키는 장치들이 개발되면서, 저온 플라즈마와 생체조직간의 상호작용에 대한 연구가 큰 관심을 끌고 있다. 플라즈마에서 발생되는 다량의 이온과 활성종, 그리고 UV 등이 박테리아나 세포들과 작용함으로 해서 암세포 사멸, 치아 미백, 박테리아 살균/멸균, 지혈등의 효과들이 나타나고 있으며, 이러한 효과들을 극대화할 수 있는 장치 개발과 플라즈마와 생체조직간의 상호작용 메카니즘을 규명하는 것이 중요한 이슈가 되고 있다. 나노 금입자를 암세포의 막단백질인 FAK의 항체와 결합시킨 중합체를 만들어서, 암세포 표면에 나노 금입자붙이고, 플라즈마를 조사했을 때, 나노 금입자가 부착되지 않았을 경우에 비해서, 5배이상 사멸률이 증가하였다.[1] 변색된 치아에 미백제의 주성분인 과산화수소를 도포하고, 10분간 플라즈마를 조사하게 되면, 과산화수소만 도포했을 때에 비해, 치아 표면의 색이 3배이상 밝아지는 것을 관찰할 수 있었다. 과산화수소를 플라즈마에 노출시켰을 때, 활성종인 OH의 생성이 2배이상 증가하였고, 플라즈마에 의한 OH 생성의 촉진이 치아 미백효과가 증대되는 주된 요인인 것으로 추측된다.[2] 플라즈마에서 발생되는 O, $O_3$와 같은 활성종들은 살균력이 뛰어나기 때문에, 저온 플라즈마를 의료기구의 소독/멸균에 응용할 가능성이 아주 크다. 대장균이나 구강 세균이 플라즈마 처리로 5분이내에 멸균되는 것을 확인하였고, 핸드피스와 같은 의료기구를 오염시켜서 멸균 테스트를 수행하고 있다.

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Study on distribution and extermination of scuticociliatids parasitizing to japanese flounder, Paralichthys olivaceus in southern Korea (남해 양식산 넙치(Paralichthys olivaceus) 치어에 기생한 스쿠티카 섬모충(scuticociliatids) 동태 및 구제에 관하여)

  • Choi, Sang-Duk;Kim, Jin-Man;Kim, Sung-Yeon;Jo, Yong-Chul;Choi, Koang-Kyu;Yang, Han-Choon
    • Journal of fish pathology
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    • v.10 no.1
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    • pp.21-29
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    • 1997
  • We investigated on the prevalence and extermination of scuticociliatids parasitic on cultured japanese flounder, Paralichthys olivaceus in land-marine tank system of southern Korea from January to February in 1997. The gills and the skin showed the highest infection rate(60%), and the brain showed the lowest(22%). Also, fish secreted large quantity of mucus with a bleeding and ulcerated lesions on the infected sites. The number of the parasites in inflowing sea water, surface water and bottom water of farming tank ranged 0~1 individuals/$100m\ell$, 0~413 individuals/$100m\ell$ and $7\sim7.3{\times}10^4$ individuals/$100m\ell$, respectively. This parasite was died within 2 hours in 50~500 ppm, 48 hours of 10 ppm formalin or hydrogen peroxide, 1 hour in 50~500 ppm, 80 minutes of 10 ppm oligo chitosan and 10 minute in 100% but did not died until 48 hours in 10~70% fresh water.

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