• 한방안이비인후피부과학회지
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• 제30권4호
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• pp.62-74
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• 2017

Objectives : The purpose of this study is to investigate the effect of laser therapy for diabetic ulcer by using methods of systematic review. Methods : In this review, PubMed, Cochrane library, Web of Science, CNKI, CiNii, J-STAGE, NDSL and OASIS were used as the search engines. The search period is from the start date of the search engine to October 3, 2016. Randomized controlled trials(RCTs) using laser therapy for diabetic ulcer were searched and extracted by two independent researchers. Risk of bias(RoB) of Cochrane was used to assess methodological quality of studies. Results : Finally, five RCTs were selected. The follow-up period ranged from 15 days to 20 weeks. InGaAlP laser, GaAlAs laser and light emitting diode(LED) were used to treat diabetic ulcer. The clinical trials used sham laser irradiation or standard treatment as control in comparison to laser therapy. The endpoints included ulcer size, rate of healing and time to healing with follow-up period. The RCTs demonstrated therapeutic outcomes with no adverse effect. Most items of RoB were unclear and methodological quality was low. Conclusions : Our analysis suggests that laser therapy has therapeutic effects for diabetic ulcer. However, more systematic and stringent clinical trials will be required.

• 한국포장학회지
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• 제19권1호
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• pp.11-15
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• 2013

도서관 등에서의 책의 위생적 유통과 관리를 위한 방안을 찾기 위하여 보관되는 책 및 관련된 환경 오염원에서의 미생물 오염도를 측정하였고, 미생물 부하를 저감시키는 방안에 대하여 연구하였다. 일반적으로 책 내부 표면의 오염도는 매우 낮으며 부주의한 취급으로 침 등과 같은 액체에 의해서 오염되는 경우에 미생물 부하가 증가될 수 있었다. 그리고 책 내부 표면에 비해서 먼지가 축적되기 쉬운 옆끝면에서 미생물 오염부하가 높았다. 책에서의 미생물적 오염의 다양성을 고려할 때, 책의 청결도 유지를 위한 조작으로서는, 미생물 부하가 많은 먼지 등의 건조 분체 오염은 공기와류 장치를 사용하고, 습윤상태의 오염은 280 nm UV LED를 사용하는 것이 적절한 것으로 나타났다. UV LED에 의한 미생물 사멸에서는 2 cm 정도의 가까운 거리에서 약 5분 정도 이상의 조사가 효과적이었고, 공기 와류에 의한 건조 분체 오염부하을 저감시키는 조건으로는 풍속 5.5 m/s에서 30초~1분의 처리가 적절하였다.

• 미생물학회지
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• 제18권4호
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• pp.161-171
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• 1980

A mutant strain having increased productivity of both enzymes, protease and amylase, was obtained from A. flavus KU 153, isolatd from South Korea for its high protease production by successive ultra-violet light irradiation, Two glucoamylases from the mutant strain selected were purified from wheat branculture by successive salting out, followed by dialysis and column chromatography, and their characteristics were compared with those of the wild strain. Glucoamylase production of the mutant selected was increased about 3.3 times compared with the wild strain, and 2.1 times compared with the parental strain, ${\alpha}-amylase$ activity of the mutant selected was about 2 times hugher than that of the wild strain or the parental strain. Protease and cellulase productivities of the muant selected were all alike compared with those of the highly proteolytic mutant, the parental strain. Therefore, it was considered that the back mutation on the protease production did not occurred in the formation process of the glucoamylase producing mutant. Total activities of glucoamylase I and II from the mutant selected were 2.86 and 3.65 times higher compared with those from the wild strain, respectively. Considering the optimal pH-thermal stability and Km-Vmax value of glucoamylase I and II from both strains, wild and mutant, it was deduced that the characteristics of glucoamylase I and II from the wild strain did not altered during the mutation process. Therefore, it was concluded that the selected mutant did not induce the formation of another glucoamylase isozyme, or the changes in the characteristics of the glucoamylase, but induce the productivity of the same glucoamylase I and II by the action of regulatory gene.

• Advances in environmental research
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• 제3권3호
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• pp.185-197
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• 2014

Efficient defluorination of perfluorooctanoic acid (PFOA) was achieved by integrating UV irradiation and $Fe^{2+}$ activation of persulfate ($S_2O{_8}^{2-}$). It was found that the UV-$Fe^{2+}$, $Fe^{2+}-S_2O{_8}^{2-}$, and UV-$S_2O{_8}^{2-}$ processes caused defluorination efficiency of 6.4%, 1.6% and 23.2% for PFOA at pH 5.0 within 5 h, respectively, but a combined system of UV-$Fe^{2+}-S_2O{_8}^{2-}$ dramatically promoted the defluorination efficiency up to 63.3%. The beneficial synergistic behavior between $Fe^{2+}-S_2O{_8}^{2-}$ and UV-$S_2O{_8}^{2-}$ was demonstrated to be dependent on $Fe^{2+}$ dosage, initial $S_2O{_8}^{2-}$ concentration, and solution pH. The decomposition of PFOA resulted in generation of shorter-chain perfluorinated carboxylic acids (PFCAs), formic acid and fluoride ions. The generated PFCAs intermediates could be further defluorinated by adding supplementary $Fe^{2+}$ and, $S_2O{_8}^{2-}$ and re-adjusting solution pH in later reaction stage. The much enhanced PFOA defluorination in the UV-$Fe^{2+}-S_2O{_8}^{2-}$ system was attributed to the fact that the simultaneous employment of UV light and $Fe^{2+}$ not only greatly enhanced the activation of $S_2O{_8}^{2-}$ to form strong oxidizing sulfate radicals ($SO{_4}^{\cdot-}$), but also provided an additional decarboxylation pathway caused by electron transfer from PFOA to in situ generated $Fe^{3+}$.

• 한국치위생학회지
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• 제19권2호
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• pp.173-181
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• 2019

Objectives: The resin infiltration technique is a promising alternative therapy for arresting the early dental caries. However, there are very few reports on the safety and biocompatibility of this technique. We evaluated various properties of resin infiltrant (RI) based on a triethylene glycol dimethacrylate (TEGDMA).The water sorption (Wsp) and water solubility (Wsl) was assessed. Additionally, the cytotoxicity of RI against both animal and human fibroblast cell lines was investigated. Methods: The RI of the $Icon^{(R)}$, the first product developed for resin infiltration, is mainly composed of TEGDMA in the resin matrix. The Wsp and Wsl for the RI were measured in accordance with ISO 4049 specifications. Fourier-transform infrared spectroscopy (FTIR) was used for analyzing the polymerization before and after curing of RI. The cytotoxicity of RI against the mouse fibroblasts (L929) and human gingival fibroblasts (hTERT-hNOF) was evaluated using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and the data were analyzed using one-way analysis of variance. Results: Wsp and Wsl of the RI specimens were $53.37{\mu}g/mm^3$ and $10.6{\mu}g/mm^3$, respectively. FTIR analysis revealed a slightly higher degree of curing with longer irradiation time. The degree of conversion for RI was high (80.9%) after 40 seconds of light curing. There was a significant decrease in the viability of L929 and hTERT-hNOF cells at RI extraction solution concentrations above 50%, respectively, compared to that in the negative control (p< 0.05). Conclusions: Even though the RI exhibited positive effect on the early prevention of dental caries, the clinicians should also consider the toxicity of RI on periodontal tissues.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.942-943
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• 2016

스테레오 감마선 탐지장치는 감마선을 신호를 측정하여 위치값을 통한 2차원의 감마선 영상을 생성 한후, 가시광영상과 중첩하여 실제 공간상의 감마선 분포를 나타낸다. 스테레오 감마선 탐지장치는 감마선 탐지센서를 포함하는 탐지부와 감마선 신호를 검출하는 신호측정부 그리고 탐지부의 위치를 제어하기 위한 모션제어부로 구성된다. 본 논문에서는 개별적으로 구성된 각각의 모듈을 효율적으로 운용하기 위한 시스템 운용 알고리즘을 개발하였고, 이를 통해 감마선 조사시험장에서 감마선에 대한 영상화 및 분포정보 출력을 확인하였다.

• Korean Journal of Chemical Engineering
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• 제35권11호
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• pp.2283-2289
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• 2018

$TiO_2$ microspheres were successfully synthesised by simple solution phase method by using various amount of titanium butoxide as precursor. The prepared $TiO_2$ were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance absorption spectra (UV-DRS), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). XRD analysis revealed that the as-synthesized $TiO_2$ microsphere poses an anatase phase. The photocatalytic degradation experiments were carried out with three different dyes, such as methylene blue, brilliant black, reactive red-120 for four hours under UV light irradiation. The results show that $TiO_2$ morphology had great influence on photocatalytic degradation of organic dyes. The experimental results of dye mineralization indicated the concentration was reduced by a high portion of up to 99% within 4 hours. On the basis of various characterization of the photocatalysts, the reactions involved to explain the photocatalytic activity enhancement due to the concentration of titanium butoxide and morphology include a better separation of photogenerated charge carriers and improved oxygen reduction inducing a higher extent of degradation of aromatics.

• 한국분말재료학회지
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• 제28권3호
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• pp.259-266
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• 2021

The (Ga_1-xZn_x)(N_1-xO_x) solid solution is attracting extensive attention for photocatalytic water splitting and wastewater treatment owing to its narrow and controllable band gap. To optimize the photocatalytic performance of the solid solution, the key points are to decrease its band gap and recombination rate. In this study, (Ga_1-xZn_x)(N_1-xO_x) nanofibers with various Zn fractions are prepared by electrospinning followed by calcination and nitridation. The effect of the composition and crystallinity of electrospun oxide nanofibers on the morphology and optical properties of the obtained solid-solution nanofibers are systematically investigated. The results show that the final shape of the (Ga_1-xZn_x) (N_1-xO_x) material is greatly affected by the crystallinity of the oxide nanofibers before nitridation. The photocatalytic properties of (Ga_1-xZn_x)(N_1-xO_x) with different Ga:Zn atomic ratios are investigated by studying the degradation of rhodamine B under visible light irradiation.

• Journal of Dental Anesthesia and Pain Medicine
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• 제22권1호
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• pp.19-27
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• 2022

Background: Myofascial pain dysfunction syndrome (MPDS) is the most common type of temporomandibular disorder. This study compared the efficacies of low-level diode laser therapy (LLLT) and laser acupuncture therapy (LAT) in the treatment of MPDS. Methods: This double-blind randomized controlled clinical trial included 24 patients with MPDS who were randomly divided into two equally sized groups. Patients in the LLLT group received 12 sessions of low-level diode laser irradiation applied to the trigger points of the masticatory muscles during 1 month. The same protocol was also used in the LAT group according to the specific trigger points. We measured pain intensity and maximum mouth opening in both groups at baseline, during treatment, and 2 months after treatment completion. Results: The pain intensities decreased from 6.58±1.31 to 0.33±0.65 and from 7.08 ± 1.37 to 0 in the LLLT and LAT groups, respectively. The maximum mouth openings increased from 32.25 ± 8.78 mm to 42.58 ± 4.75 mm and from 33 ± 6.57 mm to 45.67 ± 3.86 mm in the LLLT and LAT groups, respectively. Pain intensity (P = 0.839) and level of maximum mouth opening (P = 0.790) did not differ significantly between the groups. Conclusion: Our results showed similar efficacy between LLLT and LAT in the treatment of MPDS signs and symptoms.

• 분석과학
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• 제35권5호
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• pp.212-217
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• 2022

In this study, ozone (O₃) samples were prepared for investigating the heterogeneous reactions between O₃ and tropospheric aerosols and were characterized by spectroscopic methods. O₃ generated from an ozone generator was purified by selective adsorption on refrigerated silica gel, followed by transfer to a sample bulb. The amount of UV light (λ = 256 nm) absorbed by O₃ was measured as a function of time at two different temperatures (room temperature and 50 ℃) and under different irradiation conditions. A correlation plot of 1/[O₃] versus time showed that O₃ decomposition follows the 2^nd order reaction rate under a steady-state approximation. The initial concentration of O₃, observed rate constants (k_obs), and the half-life of O₃ in the sample stored at room temperature were determined to be 2.74 [±0.14] × 10¹⁶ molecules·cm^-3, 4.47 [±0.64] × 10^-23 molecules^-1·cm³·s^-1, and 9.5 [±1.4] days, respectively. The evaluation of O₃ stability under various conditions indicated that special care should be taken to prevent the exposure of the O₃ samples to hightemperature environment and/or UV radiation. This study established a protocol for the preparation of highly purified O₃ samples and confirmed that the O₃ samples can be stored for a day after preparation for further experiments.