Dry etching of polydimethylsiloxane using microwave plasma

Hwang, Sung Jin,Oh, Dong Joon,Jung, Phill Gu,Lee, Sang Min,Go, Jeung Sang,Kim, Joon-Ho,Hwang, Kyu-Youn,Ko, Jong Soo IOP 2009 JOURNAL OF MICROMECHANICS AND MICROENGINEERING - Vol.19 No.9

<P>This paper presents a new polydimethylsiloxane (PDMS) dry-etching method that uses microwave plasma. The applicability of the method for fabricating microstructures and removing residual PDMS is also verified. The etch rate of PDMS was dominantly influenced by the gas flux ratio of CF<SUB>4</SUB>/O<SUB>2</SUB> and the microwave power. While the PDMS etch rate increased as the flux ratio of CF<SUB>4</SUB> was increased, the etch rate decreased as the flux ratio of O<SUB>2</SUB> was increased. The maximum etch rate of 4.31 µm min<SUP>−1</SUP> was achieved when mixing oxygen (O<SUB>2</SUB>) and tetrafluoromethane (CF<SUB>4</SUB>) at a 1:2 ratio at 800 W power. The PDMS etch rate almost linearly increased with the microwave power. The ratio of the vertical etch rate to the lateral etch rate was in a range of 1.14–1.64 and varied with the gas fluxes. In consideration of potential applications of the proposed PDMS etching method, array-type PDMS microwells and network-type microprotrusion structures were fabricated. The contact angle was dramatically increased from 104° (non-etched PDMS surface) to 148° (etched PDMS surface) and the surface was thereby modified to be superhydrophobic. In addition, a thin PDMS skin that blocked holes and PDMS residues affixed in nickel microstructures was successively removed.</P>

<i>Prunella vulgaris</i> Suppresses HG-Induced Vascular Inflammation via Nrf2/HO-1/eNOS Activation

Hwang, Sun Mi,Lee, Yun Jung,Yoon, Jung Joo,Lee, So Min,Kim, Jin Sook,Kang, Dae Gill,Lee, Ho Sub Molecular Diversity Preservation International (MD 2012 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.13 No.1

<P>Vascular inflammation is an important factor which can promote diabetic complications. In this study, the inhibitory effects of aqueous extract from <I>Prunella vulgaris</I> (APV) on high glucose (HG)-induced expression of cell adhesion molecules in human umbilical vein endothelial cells (HUVEC) are reported. APV decreased HG-induced expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. APV also dose-dependently inhibited HG-induced adhesion of HL-60 monocytic cells. APV suppressed p65 NF-κB activation in HG-treated cells. APV significantly inhibited the formation of intracellular reactive oxygen species (ROS). HG-stimulated HUVEC secreted gelatinases, however, APV inhibited it. APV induced Akt phosphorylation as well as activation of heme oxygenase-1 (HO-1), eNOS, and nuclear factor E2-related factor 2 (Nrf2), which may protect vascular inflammation caused by HG. In conclusion, APV exerts anti-inflammatory effect via inhibition of ROS/NF-κB pathway by inducing HO-1 and eNOS expression mediated by Nrf2, thereby suggesting that <I>Prunella vulgaris</I> may be a possible therapeutic approach to the inhibition of diabetic vascular diseases.</P>

Anti-Proliferative Effect of an Aqueous Extract of <i>Prunella vulgaris</i> in Vascular Smooth Muscle Cells

Hwang, Sun Mi,Lee, Yun Jung,Lee, Yong Pyo,Yoon, Jung Joo,Lee, So Min,Cha, Jeong Dan,Choi, Kyung Min,Kang, Dae Gill,Lee, Ho Sub Hindawi Publishing Corporation 2013 Evidence-based Complementary and Alternative Medic Vol.2013 No.-

<P>The abnormal proliferation of vascular smooth muscle cells (VSMCs) in arterial walls is an important pathogenic factor of vascular disorders such as diabetic atherosclerosis. We have reported the anti-inflammatory effect of an aqueous extract from <I>Prunella vulgaris</I> (APV) in vascular endothelial cell. In the present study, APV exhibited inhibitory effects on high glucose-stimulated VSMC proliferation, migration, and invasion activities, inducing G<SUB>1</SUB> cell cycle arrest with downregulation of cyclins and CDKs and upregulation of the CKIs, p21<SUP>waf1/cip1</SUP> and p27<SUP>kip1</SUP>. Furthermore, APV dose dependently suppressed the high glucose-induced matrix metalloproteinase activity. High glucose-induced phosphorylation of ERK, p38 MAPK, was decreased by the pretreatment of APV. NF-<I><I>κ</I></I>B activation by high glucose was attenuated by APV, as an antioxidant. APV attenuated the high glucose-induced decrease of nuclear factor E2-related factor-2 (Nrf2) translocation and heme oxygenase-1 (HO-1) expression. Intracellular cGMP level was also increased by APV treatment. These results demonstrate that APV may inhibit VSMC proliferation via downregulating ROS/NF-<I><I>κ</I></I>B /ERK/p38 MAPK pathways. In addition, APV has a beneficial effect by the interaction of Nrf2-mediated NO/cGMP with HO-1, suggesting that <I>Prunella vulgaris</I> may be useful in preventing diabetic atherosclerosis.</P>

저농도 이산화탄소 포집용 흡착제 개발 및 최적조건에 관한 연구

이주열 ( Ju Yeol Lee ),박덕신 ( Duck Shin Park ),조영민 ( Young Min Cho ),권순박 ( Soon Park Kwon ),황윤호 ( Yoon Ho Hwang ),송형진 ( Hyung Jin Song ),이상봉 ( Sang Bong Lee ) 한국유화학회 2012 한국응용과학기술학회지 Vol.29 No.1

본 논문은 다양한 시설내에 적은 농도의 CO2 제거를 위한 선택적 CO2 흡수능력을 향상시킨 흡착제의 효율평가에 관한 것이다. 직경 4mm의 구형 흡착제는 시판용 제올라이트에 첨가제, 물, 바인더, LiOH를 섞어 제조하였다. 칼럼테스트에서 400분 이내에 90% 이상의 CO2흡착효율을 나타내었고, 흡착필터모듈 흡착능력을 평가하기 위해 회분식과 연속식타입의 챔버테스트가 시행되었다. 회분식테스트에서 30분 이내에 약 92%의 CO2가 제거되는 것을 확인하였다. 연속식테스트에서 30분 이내 70%의 CO2가 제거효율을 보였으며, 2,500ppm 이상의 CO2가 제거되는 것을 확인하였다. 재현성테스트를 수차례 수행한 결과 15일동안 1,000ppm 이상의 CO2가 연속적으로 제거됨을 보였다. TGA 분석법을 이용한 흡착량 분석에서 흡착제 g당 5.0mmol의 CO2를 흡착하는 것으로 나타났다. 본 연구에서 개발된 흡착제는 상온에서 저농도 CO2 실내환경에 적용가능한 것으로 판단된다. In this study, CO2 adsorbent was developed for removing low concentration of CO2 in multiple-use facilities. The efficiency of the adsorbent which was improved selective CO2 adsorption capabilities was evaluated. The pellet type adsorbent was modified from a commercial zeolite with mixing LiOH, binder, additives, and H2O. Column tests showed over 90 % of CO2 was adsorbed within 400min. Chamber tests including batch and continuous types were performed for evaluating the adsorbent module. By batch tests, it was evaluated that about 92 % of CO2 was removed within 30 min. By continuous tests, 70% of CO2 was removed within 30 min. It was analyzed that over 2,500 ppm of CO2 was continuously removed as shown chamber tests. The reproducibility tests repeatedly performed for 15 days shows that over 1,000 ppm of CO2 was continuously removed. Adsorption capacity of the developed adsorbent was 5.0mmol CO2/g adsorbent which was analyzed by TGA. It was estimated that the modified adsorbent was applicable to low CO2 concentration and low temperature of indoor environment.

원산지별 감초추출물의 항산화활성 증가를 위한 효율적인 추출조건 탐색

하지훈 ( Ji Hoon Ha ),이혜미 ( Hye Mi Lee ),권순식 ( Soon Sik Kwon ),김해수 ( Hae Soo Kim ),김문진 ( Moon Jin Kim ),전소하 ( So Ha Jeon ),정유민 ( Yoo Min Jeong ),황준필 ( Jun Pil Hwang ),박종호 ( Jong-ho Park ),최영기 ( Yung-key 대한화장품학회 2013 대한화장품학회지 Vol.39 No.4

본 연구에서는 한국 및 중국산 감초(Glycyrrhiza uralensis), 그리고 우즈베키스탄산 감초(Glycyrrhiza glabra)를 대상으로 추출용매, 추출온도, 추출시간 등 추출조건별 추출물을 제조하고 이들 추출물들의 추출 수율과 항산화 활성을 비교하여 최적의 추출조건을 선정하였다. 항산화 활성 중 자유 라디칼(1,1-phenyl-2-pic-rylhydrazyl, DPPH) 소거활성은 85% 에탄올로 60 ℃에서 6 h 동안 추출한 조건에서 한국 감초로부터 얻은 추출물이 가장 높은 활성(46.05%)을 나타내었다. 루미놀 발광법을 이용한 추출물들의 총 항산화능 측정 실험과 피부 광노화에 중요한 ¹O₂으로 유도된 세포막 손상에 대한 추출물들의 세포 보호 효과를 측정한 실험 모두에서도 위의 조건에서 가장 높은 항산화 활성을 나타내었다. 특히, 한국 감초는 τ₅₀이 116.4 min으로 비교 물질인(+)-α-tocopherol (28.5 min)보다 약 4 배나 높은 세포 보호 효과를 나타내었으며, 추출 수율은 18.75%로 우즈베키스탄 및 중국 감초보다 각각 1.2 배 및 2.5 배의 추출 수율을 나타내었다. 따라서, 본 연구 결과는 항산화 소재로 화장품에 응용하기 위하여 감초로부터 추출물을 얻기 위한 최적의 조건은 85% 에탄올로 60 ℃에서 6시간 동안 추출하는 것임을 보여주었다. In this work, licorice extracts were prepared using various extraction conditions such as extraction solvent, temperature, and time from Glycyrrhiza uralensis (G. uralensis) produced in Korea and China and Glycyrrhiza glabra (G. glabra) in Uzbekistan. The optimum extraction condition was selected from the extraction yields and antioxidative activities of extracts. Korea licorice extracts showed the highest free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scav-enging activity (46.05%) under the extraction condition of 85% ethanol at 60 ℃ for 6 hours. The prominent ROS (reactive oxygen species) scavenging activity using luminol-dependent chemiluminescence assay and the cellular protective effect against ¹O₂ induced cellular membrane damage were also shown from the extracts obtained from the same condition. Especially, Korea G. uralensis extracts exhibited the higher prominent protective effect (τ₅₀ = 116.4 min) than (+)-α-tocopherol (τ₅₀ = 28.5 min) and the extraction yield of Korea licorice extract was 18.75%, which is 1.2 times and 2.5 times higher than that of Uzbekistan and China, respectively. These results indicate that the extraction condition of 85% ethanol at 60 ℃ for 6 hours is optimal to prepare licorice extracts, which can be applicable as antioxidative cosmetic materials.

치과병원 진료실 내에서 메티실린 또는 반코마이신 저항성 Staphylococcus aureus의 검출

민정희,박순낭,황호길,민정범,김화숙,국중기 대한치과보존학회 2007 Restorative Dentistry & Endodontics Vol.32 No.2

본 연구는 조선대학교 치과병원의 진료환경 및 진료요원으로부터 기회감염성 병원체로 알려진 methicillin 또는 vancomycin 저항성 황색포도상 구균 (methicillin- or vancomycin-resistant Staphylococcus aureus: MRSA or VRSA)의 존재 여부를 조사하여, 이를 광주지역 개원치과와 비교분석을 통해 현재 조선대학교 치과병원의 MRSA와 VRSA의 오염정도를 파악하고자 하였다. 이를 위해 진료실 환경 및 진료요원으로부터 분리한 S. aureus 균주들의 8종 항생제에 대한 감수성 조사를 시행하고, 기존에 알려진 항생제 내성 유전자 존재 여부를 PCR법을 이용하여 확인하였다. 그 결과, 조선대학교 치과병원의 진료요원에서 채취한 샘플 중 1개 (2.3%), 개원 치과에서는 2명 (10%)의 진료요원의 샘플에서 S. aureus가 분리되었으며, 진료환경에서는 두 곳 모두에서 S. aureus가 검출되지 않았다. 조선대학교 치과병원과 개원치과에서 분리된 S. aureus는 amoxicillin, penicillin G, ciprofloxacin, clindamycin, vancomycin에 내성을 보이며, oxacillin, cefuroxime에는 균주에 따라 감수성 또는 내성을 보였다. 조선대학교 치과병원에서 분리 된 S. aureus는 erythromycin과 clindamycin에 내성 유전자인 ermA가 존재 하였으며, 개원치과에서 분리된 3개의 S. aureus 중 2개에서 penicillin과 oxacillin에 내성 유전자 mecA가 존재하는 것으로 나타났다. Vancomycin 내성 유전자인 vanA, vanB는 어떠한 샘플에서도 검출되지 않았다. 이상의 결과를 종합할 때, 본 연구는 조선대학교 치과병원과 개원치과의 S. aurues 분포 및 MRSA 또는 VRSA의 존재여부를 조사하여 MRSA와 VRSA의 확산예방을 위한 치과진료 환경의 개선과 적절한 항생제 사용에 대한 기초 자료를 제공할 것으로 사료된다. The purpose of this study was to obtain the basic information for the improvement of dental environment by investigating the presence of methicillin- or vancomycin-resistant Staphylococcus aureus (MRSA or VRSA) isolated from dental health care workers (DHCWs) and environment of the Chosun University Dental Hospital (CUDH) and a private dental clinic (control group). Staphylococcus aureus (S. aureus) was isolated from anterior nares of 42 DHCWs and 38 sites, unit chairs, x-ray devices, computers, etc., at 10 departments of the CUDH and 20 DHCWs and 11 sites at the private dental clinic. S. aureus was isolated on mannitol salt agar plate and confirmed by PCR with S. aureus species-specific primer. Antimicrobial susceptibility test of clinical isolates of S. aureus against several antibiotics including methicillin (oxacillin) was performed by investigating minimum inhibitory concentration (MIC) using broth microdilution assay. In addition, PCR was performed to detect the methicillin- or vancomycin-resistant gene. The data showed that one strain of S. aureus was isolated from DHCWs of the CUDH and three strains of S. aureus was isolated from 3 samples of the private dental clinic, respectively. All of the isolates from the CUDH and the private dental clinic had resistance to penicillin G, amoxicillin and vancomycin and susceptibility to oxacillin and ciprofloxacin. The S. aureus strains were already obtained the resistance to penicillin G and amoxicillin. These results suggest that two dental clinics were under relatively safe environment.

개에서 발생한 척수질환에 대한 추적조사(70예)

황현민,이재연,지현철,이영원,최호정,박성준,김명철,정성목 忠南大學校 獸醫科大學 附設 動物醫科學硏究所 2006 動物醫科學硏究誌 Vol.14 No.-

This study was performed to evaluate the prevalence of spinal disorders in dogs, as well as their breed, age, gender and body weight distributions. Seventy cases of caine spinal disoreders presented in the period 2001 and 2006 were reviewed. The diagnosis was obtained by survey radiographs, myelogram, CSF analysis, CT and MRI. The most frequent breed was Maltese(15 cases), and followed by Yorkshire Terrier (10 cases), Pekingese (9 cases). Canine spinal disorders occurred from 7 month to 17 year old dog, mean age was 5.3±3.7 year-old. Canine spinal disorders occurred more often in females(59.7%) than males. Mean body weight was 5.87±7.02 kg. Degenerative (39 cases, 43.3%) and anomalous (24 cases, 26.7%) disorders were dominant in 90 specific disease distribution. This results can be a reference data for the further study.

가와사끼병에서 면역글로불린 사용 후 ASO 수치의 변동에 관한 고찰

황성욱,이지웅,송민섭,김철호 인제대학교 2006 仁濟醫學 Vol.27 No.-

Objective : Since Kawasaki disease was first described in 1967, the cause and prognostic factors have not been known despite many researches and efforts. The introduction of high-dose intravenous gamma-globulin (IVGG) was an epoch and IVGG is now a standard therapy. But the mode of action of IVGG in reducing inflammatory response is not clearly understood. Understanding of the mechanism should supply the clues that indicate the cause, prognosis, the better treatment of this disease. At present, the correlation of CRP, ESR and change of leukocyte numbers to Kawasaki diseases were known, but the correlation studies of ASO titers are rare. To discover this, we evaluated the interrelationship between the ASO titer and IVGG therapy. Methods and Materials : The subjects included 35 patients with Kawasaki disease who were treated by IVGG at department of pediatrics, Inje university, Busan Paik hospital from June, 2004 to December, 2005. Before and after IVGG administration, ASO titers were evaluated. Results: In the 32 among 35 patients, ASO titers checked before IVGG administration were increased prominently after IVGG therapy. Conclusion : Remarkably increased ASO titers after IVGG administration for the treatment of Kawasaki diseases were found. And changes of ASO titers seem to be due to immunoglobulin instead of streptococcal infection. Further studies will be necessary to clarify the pathogenic mechanisms of increased ASO titers.

韓國産 玄蔘科 植物에 關한 本草學的 硏究

황성연,변종호,송호준,신민교 대한본초학회 1998 大韓本草學會誌 Vol.13 No.1

For the purpose of developing Korean Herbalogy with the plants of Scrophulariaceae which grow wild and is planted in Korea, the these and writings on herbalogy, from literature of successive generations, have been thoroughly investigative and the results obtained were as follows: 1. There were totaled to 24 genera and 85 species in Korea and among them medicinal plants are 17 genera, 45 species, some 53% in total but, the number of species may be added because of the similiar plants. 2. According to the oriental names which can be used for medical purpose, the medicinal plants belonging to the Scophulariaceae family were classified as Herba 19, Radix 4, Foilum 3, Flos, Rhizoma, Fructus 2 each. Thus it was noticed that Herba was the main kind. 3. According to sum of 85 species in Scrophulariaceae family, they were classified into Veronica genera 22, Pedicularis genera 14, Melampyrum genera 7, Euphrasia genera 6, Scrophularia genera 5, Limnophila genera, Lindernia genera, Mazus genera, Veronicastrum genera 3 each. Thus it was noticed that Veronica genera was the main kind, some 25% in total. 4. According to the number of species of the origin plants about each chinese materia medicals, they were classified into RADIX SCROPHULARIAE 5, HERBA VERONICAE, HERBA PEDICULARIS 4 each. Ths the origin plants was not complexed reletively. 5. According to nature and flavour of medicinal plants, they were classified into warmth, heat; 10 each, cold,cold; 13 each, balance 2. Ths it was noticed that cold and cool is the main in nature and flavour of medicinal plans. 6. According to the Properties and Principal curtive action, they were classified into Drugs for removing toxic heat with febrifugal and detoxicant diaphoretics 7, to remove evil heat and resolve dampness 6, tonify the blood 3, to promote or activate blood circulation by removing blood stasis, to dispel pathogenic heat from blood with drugs cold in property, to stop bleeding drugs 2 each. Thus it was noticed that Febrifugal and detoxicant drugs was the main kind. 7. Comparing to whole medicinal plants 45 kinds, toxic drug was 1 kind, 2% of the whole. Thus toxic drugs were rare. From this result, it was revealed that the plants for medical purpose in Scrophulariaceae was 53% of the whole, in which Herba was mostly abundunt and toxic plants was so rare that it will be used for clinical treatments more easily. It is considered that many experiements and clinical approaches must be continued to use Scrophulariaceae plants widely.

단근 소구치의 근관계에 관한 방사선 사진과 투명표본 간의 일치도

황호길,,강호민,서강 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.6

한 개의 치근을 가진 상, 하악 소구치의 방사선 사진 상의 근관계와 동일치아의 투명표본 상의 근관계를 각각 관찰한 다음 상호 비교하기 위해 총 142개의 소구치를 선택한 후, 구내 치과용 표준 방사선 필름을 이용하여 근원심과 협설측으로 방사선을 채득하였다. 동일하게 교육받은 4명의 판독자가 방사선 사진을 판독하여 근관계의 형태를 분류하였다. 동일한 치아에 근관와동을 형성한 후 5% NaOCl에 48시간 동안 담가 치수조직을 용해시키고 인디안 잉크를 치수강 내로 주입하여 치수조직을 염색하였다. 5% 질산용액에 48시간 동안 담가 탈회시킨 후 메틸 살리실레이트로 투명화시키고 입체현미경하에서 20배의 크기로 근관계의 형태를 평가하여 다음과 같은 결과를 얻었다. 방사선과 입체현미경 소견 간에는 판독자 간에 통계학적으로 유의한 차이를 나타냈다 (p < 0.05). 따라서 동일한 방사선 사진을 판독할 경우 판독자 간에 근관의 형태에 있어서 차이가 있을 수 있다. 그러므로 임상가는 방사선 사진을 주의깊은 판독과 예견된 근관의 형태에 따라 난이도를 고려하여 근관치료를 시행해야 할 것으로 사료된다. The aim of this study was to compare the root canal systems of maxillary and mandibular premolars that had a single root using radiographs and clearing samples. 142 single rooted premolars were selected and mesio-distal and bucco-lingual views were radiographed using intra-oral dental standard films. Four equally trained examiners classify the root canal types from the developed radiograhps. After opening the tooth for access, it was stored in 5% NaOCl to dissolve the pulp tissue. Indian ink was then injected into the pulp cavity to stain the pulp tissue. It was cleared in methyl salicylate after being decalcified with 5% nitric acid 48 hours, and the root canal type was evaluated at a magnification of × 20 using a stereomicroscope. The results are as follows; There were statistically significant differences between the radiographs and clearing samples of the root canal types among examiners (p < 0.05). There might be differences in the root canal types among examiners when the same radiograph is used. Therefore, considering the difficulty in estimating the root canal types, clinicians need to be careful when interpreting radiographs before root canal therapy.