Objectives: Although outbreak of MDR Tb has been a recent problem in western countries, it has been a longstanding problem in Korea. The poor outcome of MDR Tb is mainly due to poor compliance, high rate of side reaction of secondary drugs, and limitation in number of available drugs. Thus, to improve the outcome of MDR Tb, it is crucial to make individualized adequate prescription based on the knowledge of the patterns of resistance to each drugs in the community as well as the natural history. The purpose of present study is to evaluate the clinical features of Korean MDR Tb patients including patterns of drug resistance and success rate of treatment which was prescribed according to the sensitivity tests. Methods: Retroscpective analysis of 71 Korean patients with MDR Tb was made. All strains isolated from patients showed resistence to at least two first line drugs. Patients profile, previous treatment history, patterns of drug resistance, outcome of treatment was analysed. Initial treatment regimen was selected according to the previous treatment history and was modified according to the sensitivity reports. The regimen was composed to include at least 4 sensitive drugs when possible. Results: The patients showed resistance to 4.1 drugs on average. 90% of them were resistant to INH and RFP. Among 71 patients, 35 patients(49%) had cavitary lesions in CXR. Treatment outcome was analysed in 55 patients. 35 patients(67%) were improved after treatment and 18 patients(33%) showed treatment failure. 5 patients showed primary resistance. Treatment outcome could be evaluated in 4 of them and all showed improvement after treatment. 14 patients(20%) had to change their regimens due to drug side effects. The most frequent side effect was elevation of liver enzymes(6 patients). Others included dizziness, hyperuricemia, tinnitus, skin rash, GI troubles. More than 50% of side effects developed within 3 months. In repeated drug sensitivity test, the concordance rate of resistance to INH was 100% and RFP 98%. EMB, PZA showed 80% concordance rate. But in the other drugs, the concordances were less than 50%. Operation was done in 5 patient - 1 patients as a adjunctive means of chemotherapy -. In that case, negative conversion of sputum AFB was done. Conclusion: 2/3 patients of multidrug-resistant tuberculosis were improved by appropriate prescription and regular medication suggesting that more aggressive management and monitoring is indicated in multidrug-resistant tuberculosis.
Kim, Bo Yeon;Lee, Yoon Joo;Shin, Dong-geun;Kim, Soo Ryong;Kwon, Woo Teck;Kim, Younghee;Choi, Duck Kyun
Korean Chemical Engineering Research
/
v.53
no.5
/
pp.603-608
/
2015
Alumina powder have been expanded its application in industry and required to control its morphology such as powder size and aspect ratio of single particle. It can be synthesized by molten - salt method which is possible to obtain various shapes of ceramic particles by controlling the growth direction because each crystal face has different growth rate. In this study, various combinations of salts such as NaCl, $Na_2SO_4$, $Na_3PO_4$ and their mixture were used for control the growth of plate like alumina particle from the initial stage of synthesis because salt having different ionic strength can control the growth direction of ceramic particle under its melting condition around $800{\sim}900^{\circ}C$, and growth behavior of plate-like alumina particle with different reaction conditions such as temperature and concentration on the crystal size and shape was studied.
Sulfur-substituted $LiMn_{0.9}Cr_{0.1}O_{2-x}S_x$$(0\;\leq\;x\;\leq\;0.1)$ layered oxides have been prepared by solid state reaction under inert atmosphere. From powder X-ray diffraction analyses, all the present lithium manganates were found to be crystallized with monoclinic-layered structure. Electrochemical measurements clearly demonstrated that, in comparison with the pristine $LiMn_{0.9}Cr_{0.1}O_2$, the sulfur-substituted derivatives exhibit smaller discharge capacities for the entire cycle range but the recovery of discharge capacity after the initial several cycles becomes faster upon sulfur substitution. The effect of the sulfur substitution on the chemical bonding nature of $LiMn_{0.9}Cr_{0.1}O_{2-x}S_x$has been investigated using X-ray absorption spectroscopic (XAS) analyses at Mn and Cr K-edges. According to Mn K-edge XAS results, the trivalent oxidation state of manganese ion remains unchanged before and after the substitution whereas the local structure around manganese ions becomes more distorted with increasing the substitution rate of sulfur. On the other hand, the replacement of oxygen with sulfur has negligible influence on the local atomic arrangement around chromium ions, which is surely due to the high octahedral stabilization energy of $Cr^{+III} $ ions. Based on the present experimental findings, we have suggested that the decrease of discharge capacity upon sulfur substitution is ascribable to the enhanced structural distortion of $MnO_6$ octahedra and/or to the formation of covalent Li-S bonds, and the accompanying improvement of cyclability would be related to the depression of Mn migration and/or to the pillaring effect of larger sulfur anion.
The batch experiments by response surface methodology (RSM) have been applied to investigate the influences of operating parameters such as temperature, initial concentration, contact time and adsorbent dosage on 2,4-dichlorophenol (2,4-DCP) adsorption with an activated carbon prepared from waste citrus peel (WCAC). Regression equation formulated for the 2,4-DCP adsorption was represented as a function of response variables. Adequacy of the model was tested by the correlation between experimental and predicted values of the response. A fairly high value of $R^2$ (0.9921) indicated that most of the data variation was explained by the regression model. The significance of independent variables and their interactions were tested by the analysis of variance (ANOVA) and t-test statistics. These results showed that the model used to fit response variables was significant and adequate to represent the relationship between the response and the independent variables. The kinetics and isotherm experiment data can be well described with the pseudo-second order model and the Langmuir isotherm model, respectively. The maximum adsorption capacity of 2,4-DCP on WCAC calculated from the Langmuir isotherm model was 345.49 mg/g. The rate controlling mechanism study revealed that film diffusion and intraparticle diffusion were simultaneously occurring during the adsorption process. The thermodynamic parameters indicated that the adsorption reaction of 2,4-DCP on WCAC was an endothermic and spontaneous process.
In order to enhance ultra battery performances, the electrochemical characteristics of nano Pb/AC anode composite was investigated. Through nano Pb adsorption onto activated carbon, nano Pb/AC was synthesized and it was washed under vacuum process. The prepared anode materials was analysed by SEM, BET and EDS. The specific surface area and average pore size of nano Pb/AC composite were $1740m^2/g$ and 1.95 nm, respectively. The negative electrode of ultra battery was prepared by nano Pb/AC dip coating on lead plate. The electrochemical performances of ultra battery were studied using $PbO_2$ (the positive electrode) and prepared nano Pb/AC composite (the negative electrode) pair. Also the electrochemical behaviors of ultra battery were investigated by charge/discharge, cyclic voltammetry, impedance and rate capability tests in 5 M $H_2SO_4$ electrolyte. The initial capacity and cycling performance of the present nano Pb/AC ultra battery were improved with respect to the lead battery and the AC-coated lead battery. These experimental results indicate that the proper addition of nano Pb/AC into the negative electrode can improve the discharge capacity and the long term cycle stability and remarkably suppress the hydrogen evolution reaction on the negative electrode.
The Journal of the Korean Society for Microbiology
/
v.34
no.6
/
pp.533-542
/
1999
H. pylori produces urease abundantly amounting to 6% of total protein of bacterial mass. Urease genes are composed of a cluster of 9 genes of ureC, ureD, ureA, ureB, ureI, ureE, ureF, ureG, ureH. Production of H. pylori urease in E. coli was studied with genetic cotransformation. Structural genes ureA and ureB produce urease apoprotein in E. coli but the apoprotein has no enzymatic activity. ureC and ureD do not affect urease production nor enzyme activity ureF, ureG, and ureH are essential to produce the catalytically active H. pylori urease of structural genes (ureA and ureB) in E.coli. The kinetics of activation of H. pylori urease apoprotein were examined to understand the production of active H. pylori urease. Activation of H. pylori urease apoprotein, pH dependency, reversibility of $CO_2$ binding, irreversibility of $CO_2$ and $Ni^{2+}$ incorporation, and $CO_2$ dependency of initial rate of urease activity have been observed in vitro. The intrinsic reactivity (ko) for carbamylation of urease apoprotein co expressed with accessory genes was 17-fold greater than that of urease apoprotein expressed without accessory genes. It is concluded that accessory genes function in maximizing the carbamylating deprotonated ${\varepsilon}$-amino group of Lys 219 of urease B subunit and metallocenter of urease apoprotein is supposed to be assembled by reaction of a deprotonated protein side chain with an activating $CO_2$ molecule to generate ligands that facilitate productive nickel binding.
Journal of Korean Society of Environmental Engineers
/
v.27
no.9
/
pp.1006-1015
/
2005
We investigated the effect of hydroxyl radicals on the photolysis of triclosan (TCS), which is a potent broad-spectrum antimicrobial agent. TCS degradation during the initial reaction time of 5 min followed a pseudo-first order kinetic model ai all light intensities at a wavelength of 365 nm and at the low light intensities at a wavelength of 254 nm. The photodegradation rate significantly increased with decreasing wavelength and increasing the UV intensities. The activity of hydroxyl radicals was suppressed when methanol was used as the solvent instead of water. An increase in the photon effect was observed when the UV intensity was higher than $5.77{\times}10^{-5}$ einstein $L^{-1}min^{-1}$ at 254 nm, and lower than $1.56{\times}10^{-4}$ einstein $L^{-1}min^{-1}$ at 365 nm. The quantum yield efficiency for the photolysis of TCS was higher at 365 nm than at 254 nm among the above mentioned UV intensities. Dibenzodichloro-p-dioxin (DCDD) and dibenzo-p-dioxin were detected as intermediates at both UV intensities of $1.37{\times}10^{-4}$ and $1.56{\times}10^{-4}$ einstein $L^{-1}min^{-1}$ at 365 nm. Dichlorophenol and phenol were also detected in all cases. Based on our findings, we presented a possible mechanism of TCS photolysis.
Journal of Korean Society of Environmental Engineers
/
v.27
no.6
/
pp.657-662
/
2005
Iron sulfide(FeS) is significantly produced through both abiotic and biotic processes in natural sediments and pore waters. In this study, chromium(VI) reaction with iron sulfide at various initial concentrations and at pH values of 4 and 8 was conducted to better understand the interactions between Cr(VI) and Fe(II) species dissolved from iron sulfide in both the aqueous and solid phases. Also, the removal efficiency of iron sulfide was compared with zero valent iron and other iron bearing oxides such as ${\alpha}-Fe_2O_3$, ${\alpha}-FeOOH$ and $Fe_3O_4$. The Cr(VI) removal rate by iron sulfide was higher at pH 4 than at pH 8 because more dissolved Fe(II) existed at pH 4 than at pH 8. Chromium and iron(oxyhydroxide) could be identified on the iron sulfide surface with transmission microscopy imaging and energy dispersive spectroscopy. The removal capacity of iron sulfide was much higher than zero valent iron and other iron oxide minerals due to the synergic effect of hydrogen sulfide and ferrous iron.
Journal of Korean Society of Environmental Engineers
/
v.27
no.3
/
pp.330-336
/
2005
The ozone injection method was proposed to improve the catalytic process for the removal of nitrogen oxides ($NO_x$). Nitric oxide (NO) in the exhaust gas was first oxidized to nitrogen dioxide ($NO_2$) by ozone produced by dielectric barrier discharge, and then the exhaust gas containing the mixture of NO and $NO_2$ was directed to the catalytic reactor where both NO and $NO_2$ were reduced to $N_2$ in the presence of ammonia as the reducing agent. A commercially available $V_2O_5-WO_3/TiO_2$ catalyst was used as the catalytic reactor. The $NO_2$ content in the mixture of NO and $NO_2$ was changed by the amount of ozone added the exhaust gas. The effect of reaction temperature, initial $NO_x$ concentration, feed gas flow rate, and ammonia concentration on the removal of $NO_x$ at various $NO_2$ contents was examined and discussed. The increase in the content of $NO_2$ by the ozone injection remarkably improved the performance of the catalytic reactor, especially at low temperatures. The present ozone injection method appears to be promising for the improvement of the catalytic reduction of $NO_x$.
Isotherms, kinetics and thermodynamic properties for adsorption of acid fuchsin (AF) dye by activated carbon were carried out using variables such as dose of adsorbent, pH, initial concentration and contact time and temperature. The effect of pH on adsorption of AF showed a bathtub with high adsorption percentage in acidic (pH 8). Isothermal adsorption data were fitted to the Freundlich, Langmuir, and Dubinin-Radushkevich isotherm models. Freundlich isothem model showed the highest agreement and confirmed that the adsorption mechanism was multilayer adsorption. It was found that adsorption capacity increased with increasing temperature. Freundlich's separation factor showed that this adsorption process was an favorable treatment process. Estimated adsorption energy by Dubinin-Radushkevich isotherm model indicated that the adsorption of AF by activated carbon is a physical adsorption. Adsorption kinetics was found to follow the pseudo-second-order kinetic model. Surface diffusion at adsorption site was evaluated as a rate controlling step by the intraparticle diffusion model. Thermodynamic parameters such as activation energy, Gibbs free energy, enthalpy entropy and isosteric heat of adsorption were investigated. The activation energy and enthalpy change of the adsorption process were 21.19 kJ / mol and 23.05 kJ / mol, respectively. Gibbs free energy was found that the adsorption reaction became more spontaneously with increasing temperature. Positive entropy was indicated that this process was irreversible. The isosteric heat of adsorption was indicated physical adsorption in nature.
본 웹사이트에 게시된 이메일 주소가 전자우편 수집 프로그램이나
그 밖의 기술적 장치를 이용하여 무단으로 수집되는 것을 거부하며,
이를 위반시 정보통신망법에 의해 형사 처벌됨을 유념하시기 바랍니다.
[게시일 2004년 10월 1일]
이용약관
제 1 장 총칙
제 1 조 (목적)
이 이용약관은 KoreaScience 홈페이지(이하 “당 사이트”)에서 제공하는 인터넷 서비스(이하 '서비스')의 가입조건 및 이용에 관한 제반 사항과 기타 필요한 사항을 구체적으로 규정함을 목적으로 합니다.
제 2 조 (용어의 정의)
① "이용자"라 함은 당 사이트에 접속하여 이 약관에 따라 당 사이트가 제공하는 서비스를 받는 회원 및 비회원을
말합니다.
② "회원"이라 함은 서비스를 이용하기 위하여 당 사이트에 개인정보를 제공하여 아이디(ID)와 비밀번호를 부여
받은 자를 말합니다.
③ "회원 아이디(ID)"라 함은 회원의 식별 및 서비스 이용을 위하여 자신이 선정한 문자 및 숫자의 조합을
말합니다.
④ "비밀번호(패스워드)"라 함은 회원이 자신의 비밀보호를 위하여 선정한 문자 및 숫자의 조합을 말합니다.
제 3 조 (이용약관의 효력 및 변경)
① 이 약관은 당 사이트에 게시하거나 기타의 방법으로 회원에게 공지함으로써 효력이 발생합니다.
② 당 사이트는 이 약관을 개정할 경우에 적용일자 및 개정사유를 명시하여 현행 약관과 함께 당 사이트의
초기화면에 그 적용일자 7일 이전부터 적용일자 전일까지 공지합니다. 다만, 회원에게 불리하게 약관내용을
변경하는 경우에는 최소한 30일 이상의 사전 유예기간을 두고 공지합니다. 이 경우 당 사이트는 개정 전
내용과 개정 후 내용을 명확하게 비교하여 이용자가 알기 쉽도록 표시합니다.
제 4 조(약관 외 준칙)
① 이 약관은 당 사이트가 제공하는 서비스에 관한 이용안내와 함께 적용됩니다.
② 이 약관에 명시되지 아니한 사항은 관계법령의 규정이 적용됩니다.
제 2 장 이용계약의 체결
제 5 조 (이용계약의 성립 등)
① 이용계약은 이용고객이 당 사이트가 정한 약관에 「동의합니다」를 선택하고, 당 사이트가 정한
온라인신청양식을 작성하여 서비스 이용을 신청한 후, 당 사이트가 이를 승낙함으로써 성립합니다.
② 제1항의 승낙은 당 사이트가 제공하는 과학기술정보검색, 맞춤정보, 서지정보 등 다른 서비스의 이용승낙을
포함합니다.
제 6 조 (회원가입)
서비스를 이용하고자 하는 고객은 당 사이트에서 정한 회원가입양식에 개인정보를 기재하여 가입을 하여야 합니다.
제 7 조 (개인정보의 보호 및 사용)
당 사이트는 관계법령이 정하는 바에 따라 회원 등록정보를 포함한 회원의 개인정보를 보호하기 위해 노력합니다. 회원 개인정보의 보호 및 사용에 대해서는 관련법령 및 당 사이트의 개인정보 보호정책이 적용됩니다.
제 8 조 (이용 신청의 승낙과 제한)
① 당 사이트는 제6조의 규정에 의한 이용신청고객에 대하여 서비스 이용을 승낙합니다.
② 당 사이트는 아래사항에 해당하는 경우에 대해서 승낙하지 아니 합니다.
- 이용계약 신청서의 내용을 허위로 기재한 경우
- 기타 규정한 제반사항을 위반하며 신청하는 경우
제 9 조 (회원 ID 부여 및 변경 등)
① 당 사이트는 이용고객에 대하여 약관에 정하는 바에 따라 자신이 선정한 회원 ID를 부여합니다.
② 회원 ID는 원칙적으로 변경이 불가하며 부득이한 사유로 인하여 변경 하고자 하는 경우에는 해당 ID를
해지하고 재가입해야 합니다.
③ 기타 회원 개인정보 관리 및 변경 등에 관한 사항은 서비스별 안내에 정하는 바에 의합니다.
제 3 장 계약 당사자의 의무
제 10 조 (KISTI의 의무)
① 당 사이트는 이용고객이 희망한 서비스 제공 개시일에 특별한 사정이 없는 한 서비스를 이용할 수 있도록
하여야 합니다.
② 당 사이트는 개인정보 보호를 위해 보안시스템을 구축하며 개인정보 보호정책을 공시하고 준수합니다.
③ 당 사이트는 회원으로부터 제기되는 의견이나 불만이 정당하다고 객관적으로 인정될 경우에는 적절한 절차를
거쳐 즉시 처리하여야 합니다. 다만, 즉시 처리가 곤란한 경우는 회원에게 그 사유와 처리일정을 통보하여야
합니다.
제 11 조 (회원의 의무)
① 이용자는 회원가입 신청 또는 회원정보 변경 시 실명으로 모든 사항을 사실에 근거하여 작성하여야 하며,
허위 또는 타인의 정보를 등록할 경우 일체의 권리를 주장할 수 없습니다.
② 당 사이트가 관계법령 및 개인정보 보호정책에 의거하여 그 책임을 지는 경우를 제외하고 회원에게 부여된
ID의 비밀번호 관리소홀, 부정사용에 의하여 발생하는 모든 결과에 대한 책임은 회원에게 있습니다.
③ 회원은 당 사이트 및 제 3자의 지적 재산권을 침해해서는 안 됩니다.
제 4 장 서비스의 이용
제 12 조 (서비스 이용 시간)
① 서비스 이용은 당 사이트의 업무상 또는 기술상 특별한 지장이 없는 한 연중무휴, 1일 24시간 운영을
원칙으로 합니다. 단, 당 사이트는 시스템 정기점검, 증설 및 교체를 위해 당 사이트가 정한 날이나 시간에
서비스를 일시 중단할 수 있으며, 예정되어 있는 작업으로 인한 서비스 일시중단은 당 사이트 홈페이지를
통해 사전에 공지합니다.
② 당 사이트는 서비스를 특정범위로 분할하여 각 범위별로 이용가능시간을 별도로 지정할 수 있습니다. 다만
이 경우 그 내용을 공지합니다.
제 13 조 (홈페이지 저작권)
① NDSL에서 제공하는 모든 저작물의 저작권은 원저작자에게 있으며, KISTI는 복제/배포/전송권을 확보하고
있습니다.
② NDSL에서 제공하는 콘텐츠를 상업적 및 기타 영리목적으로 복제/배포/전송할 경우 사전에 KISTI의 허락을
받아야 합니다.
③ NDSL에서 제공하는 콘텐츠를 보도, 비평, 교육, 연구 등을 위하여 정당한 범위 안에서 공정한 관행에
합치되게 인용할 수 있습니다.
④ NDSL에서 제공하는 콘텐츠를 무단 복제, 전송, 배포 기타 저작권법에 위반되는 방법으로 이용할 경우
저작권법 제136조에 따라 5년 이하의 징역 또는 5천만 원 이하의 벌금에 처해질 수 있습니다.
제 14 조 (유료서비스)
① 당 사이트 및 협력기관이 정한 유료서비스(원문복사 등)는 별도로 정해진 바에 따르며, 변경사항은 시행 전에
당 사이트 홈페이지를 통하여 회원에게 공지합니다.
② 유료서비스를 이용하려는 회원은 정해진 요금체계에 따라 요금을 납부해야 합니다.
제 5 장 계약 해지 및 이용 제한
제 15 조 (계약 해지)
회원이 이용계약을 해지하고자 하는 때에는 [가입해지] 메뉴를 이용해 직접 해지해야 합니다.
제 16 조 (서비스 이용제한)
① 당 사이트는 회원이 서비스 이용내용에 있어서 본 약관 제 11조 내용을 위반하거나, 다음 각 호에 해당하는
경우 서비스 이용을 제한할 수 있습니다.
- 2년 이상 서비스를 이용한 적이 없는 경우
- 기타 정상적인 서비스 운영에 방해가 될 경우
② 상기 이용제한 규정에 따라 서비스를 이용하는 회원에게 서비스 이용에 대하여 별도 공지 없이 서비스 이용의
일시정지, 이용계약 해지 할 수 있습니다.
제 17 조 (전자우편주소 수집 금지)
회원은 전자우편주소 추출기 등을 이용하여 전자우편주소를 수집 또는 제3자에게 제공할 수 없습니다.
제 6 장 손해배상 및 기타사항
제 18 조 (손해배상)
당 사이트는 무료로 제공되는 서비스와 관련하여 회원에게 어떠한 손해가 발생하더라도 당 사이트가 고의 또는 과실로 인한 손해발생을 제외하고는 이에 대하여 책임을 부담하지 아니합니다.
제 19 조 (관할 법원)
서비스 이용으로 발생한 분쟁에 대해 소송이 제기되는 경우 민사 소송법상의 관할 법원에 제기합니다.
[부 칙]
1. (시행일) 이 약관은 2016년 9월 5일부터 적용되며, 종전 약관은 본 약관으로 대체되며, 개정된 약관의 적용일 이전 가입자도 개정된 약관의 적용을 받습니다.