• Tuberculosis and Respiratory Diseases
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• 제83권3호
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• pp.211-217
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• 2020

The gold standard method for diagnosis of tuberculosis is the isolation of Mycobacterium tuberculosis through culture, but there is a probability of cross-contamination in simultaneous cultures of samples causing false-positives. This can result in delayed treatment of the underlying disease and drug side effects. In this paper, we reviewed studies on false-positive cultures of M. tuberculosis. Rate of occurrence, effective factors, and extent of false-positives were analyzed. Ways to identify and reduce the false-positives and management of them are critical for all laboratories. In most cases, false-positive is occurring in cases with only one positive culture but negative direct smear. The three most crucial factors in this regard are inappropriate technician function, contamination of reagents, and aerosol production. Thus, to reduce false-positives, good laboratory practice, as well as use of whole-genome sequencing or genotyping of all positive culture samples with a robust, extra pure method and rapid response, are essential for minimizing the rate of false-positives. Indeed, molecular approaches and epidemiological surveillance can provide a valuable tool besides culture to identify possible false positives.

• 천문학회보
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• 제39권1호
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• pp.54.1-54.1
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• 2014

Kyung Hee University has been developing a CubeSat for the space science mission called SIGMA (Scientific cubesat with Instrument for Global Magnetic field and rAdiation), which includes TEPC (Tissue Equivalent Proportional Counter) and a magnetometer. SIGMA has a 3-unit CubeSat, and the weight is about 3.2 kg. The main payload is TEPC which can measure the Linear Energy Transfer (LET) spectrum and calculate the equivalent dose for the complicated radiation field in the space. The magnetometer is a secondary payload using a miniaturized fluxgate magnetometer. We expect it to have a 1 nT resolution in the dynamic range of ${\pm}65535$ nT. An Attitude Control System (ACS) spins the SIGMA spacecraft 4 rpm with the spin axis perpendicular to the ecliptic plane. Full duplex communication is consists of VHF uplink and S-band and UHF downlink. In this paper, we introduce the system design and the scientific purpose of the SIGMA CubeSat mission.

• 한국정보통신학회논문지
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• 제20권2호
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• pp.359-366
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• 2016

방사선 치료에 있어서 정상 조직에는 방사선을 최소화 하고 종양 부위에 정확한 방사선을 집중해서 조사하여 국소 종양 제어율(Local Tumor Rate)을 극대화 하는 것이 가장 중요하다. 이를 위해서 초기에는 치료사들이 직접 환자의 움직임을 감지했으나 정확도가 떨어지고 치료사들의 피로가 가중되는 문제점들이 있었다. 또한 웹카메라를 이용하여 기준영상과 갱신되는 영상의 차분값을 계산하여 그 결과가 기준값을 초과하면 움직임이 발생한 것으로 판단하는 시스템을 사용하였다. 그러나 이 시스템은 환자의 움직임을 정량적으로 분석할 수 없고 토모치료기의 치료베드 이동시 변화되는 배경을 환자와 가려낼 수 없었다. 이에 본 논문에서는 이러한 한계점을 해결하고자 지수가중치(${\alpha}$) 필터를 이용하여 환자의 움직임을 정량화 하고 환자와 치료환경의 배경이미지를 분리하여 치료중 환자의 움직임만을 감지하여 환자의 움직임으로 인한 문제를 줄일 수 있었다.

• KSBB Journal
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• 제13권2호
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• pp.155-161
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• 1998

The hairy roots of Crotalaria sessiliflora were induced from the tissue segments infected with Agrobacterium rhizogenes ATCC 15834. The induced hairy roots were subjected to paper electrophoresis fro the detection of opine-positive clones which were considered to have been transformed. Mannopine and agropine were presented in hairy root clones while mannopine was presented in two hairy root clones. Eight hairy root clones were selected and cultured in MS, B5 and WP media. Each of hairy root clones was showed a difference in branch pattern and growth rate. The best culture medium and culture conditions of hairy roots were in $\frac{1}{2}$MS(3% sucrose, pH 5.7) liquid medium at 25$^\circ C$, 70 rpm under dark, the growth rate in $\frac{1}{2}$MS liquid medium was increased with 210-fold more than that of inoculated hairy roots and with 2-fold more than that in MS liquid medium. Also, the adequate condition for hairy root growth was such that concentration of KH$_2PO$_4 was 1.25mM and the ratio of NH${_4}{^+}$ : NO${_3}{^-}$ was 1 to 3 in MS medium. The presence of pyrrolizidine alkaloids, monocrotaline, in the hairy roots was detected by TLC.

• Biomaterials and Biomechanics in Bioengineering
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• 제2권1호
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• pp.23-32
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• 2015

Facile immobilization of growth factors in hyaluronic acid (HA) hydrogels using dual enzymes is reported in the paper. The hydrogels were formed by using horseradish peroxidase (HRP) and hydrogen peroxide ($H_2O_2$) and transforming growth factor-${\beta}3$ (TGF-${\beta}3$) was covalently conjugated on the hydrogels in situ using tyrosinase (Ty) without any modifications. For the preparation of hydrogels, HA was grafted with poly(ethylene glycol) (PEG), which was modified with a tyrosine. The gelation times of the HA hydrogels were ranging from 415 to 17 s and the storage moduli was dependent on the concentration of $H_2O_2$ and Ty (470-1600 Pa). A native TGF-${\beta}3$ (200 ng/mL) was readily encapsulated in the HA hydrogels and 17% of the TGF-${\beta}3$ was released over 1 month at the Ty concentration of 0.5 KU/mL, while the release was faster when 0.3 KU/mL of Ty was used for the encapsulation (27%). It can be suggested that the growth factors resident in the hydrogels for a long period of time may lead cells proliferating and differentiating, whereas the growth factors that are initially released from the hydrogels can induce the ingrowth of cells into the matrices. Therefore, the dual enzymatic methods as facile gel forming and loading of various native growth factors or therapeutic proteins could be highly promising for tissue regenerative medicines.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제13권1호
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• pp.110-116
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• 1991

하악골 골절시 감염으로 인한 합병증에는 비유합, 부정유합, 감염에 의한 골수염, 치아 및 지지골 상실, 국소부위로부터 인접부위로 감염확장 등이 있다. 그 원인으로는 크게 국소요인과 전신요인으로 분류되는데 국소요인으로는 부적절한 고정과 수복, 감염 및 개조된 혈액공급을 들 수 있고 전신 요인으로는 부적절한 고정과 수복, 감염 및 개조된 혈액 공급을 들 수 있는 전신요인으로는 환자의 나이 및 대상장애 질환이나 primary bone disease, 영양결핍을 들 수 있다. 악골골절과 관련된 골수염은 조기에 적절한 고정 및 치료, 항생제 요법, 골절선상의 치아에 대한 치료, 전신적 저항성을 항진 시킴으로서 예방할 수 있다. 본 저자들은 하악골 골절수 이차감염으로 인한 골수염에서 골 이식의 일반적인 원칙인 감염이 없는 부위가 아닌 염증이 존재한 부위에 유리장골 이식술과 고압산소 요법을 병행하여 양호한 결과를 얻었기에 이에 보고하는 바이다.

• 대한치과보철학회지
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• 제27권1호
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• pp.55-81
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• 1989

Recently the instantaneous center concept has been to understand the biomechanics by which a tissue derangement causes a mechanical derangement in human joint. Therefore, to understand the biomechanics of temporomandibular joint (T.M.J.) as a part of human joint, it is necessary to clarify the instantaneous center of rotation (I.C.R.) in the mandibular movement. Twenty male subjects without T.M.J. disorder and mandibular deviation during the mandibular movement were selected for this study. The habitual opening and closing paths were recorded on the paper of the sagittal metal plate by two pencil markers connected to the resin open clutch attached on the lower teeth, which was designed for this study. The coordinates of the 33-target points and the 109-anatomical landmarks were obtained using a Summagraphic digitizer connected to a 18AT computer. The original raw data of the opening and closing paths were smoothed by B-spline curve fitting technique and then the I.C.R. pathways were determined mathematically by the computer using algorithm for finding the I.C.R. of a planer rigid body model. Also the opening and closing movements of the mandible were simulated according to the determined I.C.R. The results obtained from this study were as follows. 1. At the early opening and the last closing, I.C.R's were almost distributed around the mastoid process outside the mandibular body without the presence in the region of the mandibular condyle. 2. The I.C.R. pathway showed variable patterns to each subject at the opening and closing movements. 3. The K constant with uniform pattern was obtained by the rotation angle times the radius, which was assumed to the index of the mandibular movement. 4. The opening and closing movements of the mandible were simulated by the I.C.R. pathways at the habitual opening and closing movements. 5. The mandibular condyle was rotated or translated accordng to the relative rotation angle and radius of the determinant factors of K contant.

• Journal of Periodontal and Implant Science
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• 제39권1호
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• pp.37-44
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• 2009

Purpose: Tetracycline and its chemically modified non-antibacterial analogues can inhibit certain host-derived tissue destructive collagenases such as matrix metalloproteinases. The purpose of this study was to evaluate clinical and microbiologic effects of the subantimicrobial dose of doxycycline(SDD) in conjunction with scaling and root planing. Materials and methods: A total of 30 patients with chronic periodontitis who were going to receive scaling and root planing were randomly allocated to receive either a doxycycline hyclate for 3 months or nothing. Clinical probing depth, clinical attachment level, gingival recession, and bleeding on probing were measured by one periodontist. After a periodontal examination, microbial samples were collected using sterile paper points. The effect of SDD in conjunction with scaling and root planing on alterations of the periodontal pathogens (Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Porphyromonas gingivalis) were also assessed using l6S rRNA polymerase chain reaction. Results: During the treatment period, clinical parameters for both treatment group and control group were improved. After 3 months, reductions in probing depth and gains in clinical attachment level were significantly greater for the SDD group than control group. Microbial analysis showed that there was no alteration of the periodontal pathogens and no difference between the groups. Conclusion: This study suggested that the subantimicrobial dose of doxycycline as an adjunct therapy with scaling and root planing might be effective and safe in the management of chronic periodontitis.

• Journal of electromagnetic engineering and science
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• 제14권3호
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• pp.267-272
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• 2014

Hyperthermia is a form of cancer treatment in which affected human tissue is exposed to $>40^{\circ}C$ temperature. In this paper, our goal is to assess the efficacy of fullerene agents to reduce heating time for cancer treatment. Such agents can accelerate heating of cancer cells and improve hyperthermia treatment efficacy. Typically, in vitro testing involves cancer cell culturing, heating cell cultures in accordance to specifications, and recording cancer cell viability after hyperthermia. To heat cell cultures, we design and evaluate a 2.4-GHz microwave cavity with controllable temperature. The cavity is comprised of a polystyrene cell culture dish (diameter = 54 mm, height = 13.5 mm) and a printed monopole antenna placed within the cavity for microwave heating. The culture temperature can be controlled through the intensity and duration of the antenna's microwave radiation. Heating experiments were carried out to validate the cavity's performance for F-12K culture medium (Kaighn's F-12K medium, ATCC). Importantly, fullerene agents were shown to reduce heating time and improve hyperthermia treatment efficacy. The culture medium temperature increased, on average, from $24.0^{\circ}C$ to $50.9^{\circ}C$ (without fullerene) and from $24.0^{\circ}C$ to $56.8^{\circ}C$ (with 3 mg/mL fullerene) within 15 minutes.

• 한국환경보건학회지
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• 제22권4호
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• pp.25-32
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• 1996

The Bioconcentration factor(BCF) is used as an important criterion in the risk assessment of environmental contaminants. Also it can be used as indicator of biomagnification of environmentally hazardous chemicals through food-chain as well as a tool for ranking the bioconcentration potential of the chemicals in the environment. This paper reports the measured BCF value on carbofuran in Carassius auratus(goldfish), under steady state, and examined corelation between the BCF value and the depuration rate constant. Carassius auratus(goldfish) was chosen as test organism and test periods were 1-day, 3-day and 5-day. Experimental concentrations were 0.05, 0.10 and 0.50 ppm. Carbofuran in fish tissue and in test water was extracted with n-hexane and acetonitril. GC-ECD was used to detect and quantitate carbofuran. The depuration rate of carbofuran from the whole body of goldfish is determined over the 24-h period after treatment. The obtained results were as follows: 1. It was possible to determine short term BCFs of carbofuran through relatively simple procedure in environmental concentrations. 2. $BCF_1$ of carbofuran in concentration of 0.05, 0.10 and 0.50 ppm were 1.66, 1.64 0.61, $BCF_3$ were 2.08, 2.14, 0.66 and $BCF_5$ were 2.21, 2.57, 0.86, respectively. 3. Carbofuran concentration in fish extract was increased as increasing test concentration and prolonging test period, but $BCF_s$ in concentration of 0.50 ppm was greately decreased. 4. Determined deputation rate constants of carbofuran in concentration of 0.05, 0.10, 0.50 ppm were 0.076, 0.082 and 0.089, respectively. 5. It is considered that great decrease of $BCF_s$ in concentration of 0.50 ppm is due to high water solubility and stability of carbofuran in testwater. 6. It is suggested that low BCF of carbofuran is due to its relatively high water solubility and depuration rate, compared to BPMC, carbaryl and chlorothalonil.