TiAIN을 코팅한 WC공구의 절삭성능에 관한 연구

김현자,최현철,김영대,김일선,노태영,이규용 釜慶大學校 2001 釜慶大學校 論文集 Vol.6 No.-

Thin film of TiAlN was deposited onto ISO P20 tungsten carbide cutting insert tip substrate specimen using the FVAS (filtered vacuum arc system) at the substrate temperature of 80℃. Cutting and wear tests have been performed to the TiAlN coated and uncoated WC specimen, respectively under the same cutting conditions for the comparison. Cutting forces and tool wear of coated and uncoated carbide cutting tools were investigated by means of cutting length and cutting forces. Also tool wear and tool life were analyzed using the 3ch tool dynamometer amp lifier and oscilloscope. In this study cutting tests for the cutting performance of TiAlN coated WC-Co P20 to the steel alloy of SNCN420 have been curried out. Through the comparisons of cutting forces during the cutting tests and tool wear, we got the conclusions as follows.; ① In usual cutting conditions, main cutting force component showed higher value than the thrust force normal to the cutting direction especially cutting forces in the of early stage on cutting tests. But, after loosing the protective hard thin film on substrate or insert tip, the thrust force normal to the cutting direction showed much higher than main cutting force component. ② Within the range of 0.3㎜ build up edge in P20 insert tip, TiAlN coated tip was evaluated more stable in flank wear and less in crater wear than the uncoated specimen. ③ Through the wear growth curve of the specimen, tool life differences of uncoated and TiAlN coated tip at high speed (V=250[m/min]) was higher than the low speed(V=200[m/min]) case, compared to the average but the tool wear was almost same in both specimen for the case of normal wear occurred.

생체분해성 망막압정을 이용한 망막고정에 대한 실험적 연구

김용백,민병무,김창식,박근성,김승영,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Biodegradable retinal fixation devices obtain mechnical fixation of the retina with desirable chorioretinal scarring and with the potential for local, sustained release of antimetabolites and steroids to inhibit proliferative vitreoretinopathy. We manufactured a biodegradable retinal tack with barb that was designed in order to prevent intrusion from implantation of retinal tacks. This study was carried to evaluate the efficacy for retinal fixation and the capability for sustained release of drugs with a newly designed biodegradable retinal tack Biodegradable retinal tacks were made of polymers of glycolic acids and were designed with barbs in a shape to prevent the disinsertion. Biodegradale retinal tacks are divided into 3 parts, a conical portion that is inserted into the sclera, a cylinder portion that remains in the vitreous, and a neck portion between the pin and the cylinder. The tapered conical end was manufactured to allow easy insertion through the retina and choroid into the sclera. A cylinder portion was manufactured with a tapered angle that fixes firmly into the orifice of 19 gauge spinal needle. A neck portion, 0.4 mm in diameter, was designed to prevent disinsertion from following implantation of retinal tack. The applicator was a 19 gauge spinal needle and its orifice was prepared to 15°angle to accept the tapered cylinder portion of the retinal tack. The retinal tacks, secured in the needles, were passed through the formed vitreous and inserted into the retina, choroid, and sclera and were released by pushing the internal needle, usually within 2-3mm of the medullary ray of the posterior rabbit retina A retinal tack was placed in each of 8 pigmented rabbit eyes. Slit-lamp biomicroscopy, indirect ophthalmoscopy and fundus photography were performed periodically from 1 day to 8 weeks after surgery. Eight eyes were enucleated and studied by light microscopy at 8 weeks. Biomicroscopic evaluation of the animals revealed edemas adjacent to the retinal surfaces immediately after insertion of the biodegradable retinal tacks in all the animals. These edemas disappeared after 1 week. The first noticeable change in the size of retinal tacks was shown after 2weeks. The size of the retinal tacks gradually got smaller, decreasing to about one-half at 4 weeks and about one-third at 8 weeks. All retinal tacks remained in inserted places without any movement for an 8 week period. On light microscopy, epiretinal proliferations were seen to extend into the vitreous cavity. Cellular capsules that lined the inner aspect of the scleral defect caused by tack insertion were found. However the adjacent retina had a normal cytologic appearance and architecture in all specimens. We manufactured a biodegradable retinal tack that is designed to prevent intrusion from implantation of retinal tacks. All biodegradable retinal tacks reduce in size with time, but no retinal tacks extruded from the inserted place. The newly designed biodegradable retinal tack can be used for retinal fixation and may be used as a vehicle for the introduction of pharmacologic agents to prevent the cellular events that promote proliferative vitreoretinopathy.

Aspergillus candidus F1484 균주가 생산하는 항진균 화합물의 분리 및 특성

김성옥,이소영,김성규,손광희,김영국,문석식,복성해 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.5

Candida albicans의 효모형태에 대해 활성을 나타내는 항진균 물질의 탐색 중에 Aspergillus candidus F1484 균주의 발효액으로부터 항진균 화합물 F1484를 단리하고 ethyl acetate 추출, silica gel column chromatography, ODS column chromatography 및 preparative HPLC를 행하여 분리정제하였다. F1484 화합물은 EI-MS, ^13C-, ^1H-NMR, DEPT, HMQC 및 HMBC에 의한 구조분석을 행한 결과 이 화합물은 항진균 물질인 chloroflavonin과 동일한 구조를 나타내었으며 효모형태의 Candida albicans에 대한 항진균 활성뿐만 아니라 여러 종류의 인체 종양 세포주에 대해서도 세포독성을 나타내었다. In the course of screening for the antifungal compounds against Candida albicans, an antifungal compound (F1480) was isolated from the culture broth of Aspergillus candidus F1484. Isolation and purification of compound F1484 were performed using ethyl acetate extraction, silica gel column chromatography, ODS column chromatography, and preparative HPLC. The structure of compound F1484 was determined by the spectroscopic analyses of EI-MS, ^13C-, ^1H-NMR, DEPT, HMQC, and HMBC. This compound appeared to have a structure of antifungal agent, chloroflavonin. In addition to antifungal activities against the yeast phase of Candida species, compound F1484 showed cytotoxic effect against various human tumor cell lines.

MgCl₂溶液內에서 STS 304 HP Stainless Steel 熔接部의 破壞擧動에 對한 硏究

金永奭,丁太權,朴昌彦,洪錫柱,梁仁榮,金基玉,朴煥奎,李茂錫,曺圭宰,鄭在康 조선대학교 생산기술연구소 1983 生産技術硏究 Vol.1983 No.-

This paper is based on an experiment analysing the stress corrosion cracking behaviour of welding specimens compared to that of non-welding specimens of STS 304 HP stainless steel in corrosion solution. As a corrosion condition, stainless steel has been known to be the most fragile in a solution of 42% MgCl₂heated to the boiling point, therefore the experiment was carried out in this condition. The experiment was carried out with argon gas TIG welding specimens and non-welding ones made of stainless steel plates, thickness 2mm, by tensile force. At this time, the tensile force was taken to be the value of the yield strength of the tensile test specimens divided by the safety factor of 3.0 to 3.5, 4.0, 4.5, and 5.0. In this paper, the relations between Time of Initial Crack, Time of Failure, Time of Final Fracture and Crack Propagation Length were investigated and then plotted. Furthermore, the relations between Stress Intensity Factor K proposed by Irwin and the Time of Initial Crack, the Time of Failure, the Time of Final Fracture were calculated and plotted. At the last, all the relations plotted were expressed to normal equations by computer, and the equations were used to analyse the data obtained in the experiment. The conclusions obtained in this study are as follows: 1. Welding materials, compared with non-welding ones, as the Time of Initial Crack, the Time of Failure, and the Time of Final Fracture were generally very fast, appeared to be a phenomenon of unstable brittleness fracture. 2. Non-welding materials, compared with welding ones, as the safety factor was larger or the working stress was smaller, appeared to be a phenomenon that the longer had had greater durability. Therefor, welding materials must be considered enough to be used in heate affected and stress corrosion atmosphere. 3. The normal equations of the Time of Initial Crack and the variation rate to the same Stress Intensity Factor K are as follows: (A) Non-welding T =259702.4-5451.2 K+28.386 K² T = -5451.2+28.386 K (B) Welding T= -332.693+28.043 K-0.211 K² T' =28.043-0.211 K here, T; Time of Initial Crack, T'; Variation Rate of Time of Initial Crack to Stress Intensity Factor K, K ; Stress Intensity Factor.

독성물질의 세포사 기전 및 세포사 유발물질의 검색법 개발에 관한 연구(Ⅱ) : 망간 신경독성을 이용한 파킨슨증 모델의 세포사 Studies on the Mechanism of Parkinsonism induced by Manganese

김종민,박창원,오정자,이보경,서경원,서수경,김규봉,김종원,김광진,김영옥,전범석,박찬웅,이선희 식품의약품안전청 2001 식품의약품안전청 연보 Vol.5 No.-

1960년대 이후 파킨슨병의 유발물질 중 한 후보로서 망간이 주목받으면서 많은 역학적, 병러학적 연구가 수행죄브다. 그러나 망간이 파킨슨병을 직접 일으키는지, 혹은 파킨슨병과 관련된 부위의 신경세포를 파괴시쿡 파킨슨증만을 초래하는 것인지가 아직 정립되지 않은 실정이다 본 연구에서는 실험동물모델에서 행등학적 변화 측정 및 병리학적, 샐화학적 연구를 통하여 망간의 과다노출글 따른 파킨슨병 유발 여부를 확인하고자 하였다. Sprague-Datylet· 렛드에 망간을 1, 2, 5, 10 mgAg/day의 응량으로 30일 등안 복강 투여하였을 때 모든 망간투여군에서 운동성 감소가 관찰되었다. 뇌조직의 망간 함량을 ion chromatograph?로 측정한 결과 중뇌 흑질과 기저핵 선조체에서 망간 함량의 뚜렷한 증가 소견이 관찰되었으며, 니슬염색체서 선조체의 신경세포수의 유의성 있는 감소가 관찰되었다. 그러나, 흑질의 TH효소 면역염색, GFAP 면역염색, 흑질과 선조체의 T릿효소 western blot 결과는 대조군과 차이가 없었다. 이상의 결과에서, 망간-파킨슨증 모델에서 파킨슨증어 유발되는 기전은 흑질 도파민성 신경 세포의 신호를 받는 선조체 씬경세포의 사멸에 의한 것으로 생각된다. 결론적으로, 망간 독성에 의한 파킨스증 모델에서는 파킨슨 병과는 달리 흑질 도파민성 신경세포의 세포사는 관여하지 않는 것으로 관찰되었다. Manganese(Mn) intoxication causes a parkinsonian syndrome. It may be difficult to distinguish Mn-induced parkinsonism from idiopathic Parkinson disease(IPD). Neuropathological descriptions on the brains with Mn intoxication showed the perferential damage in the globus pallidus and substantia nigra pars reticularis. Pathological reports on the substantia nigra pars compacta(SNpc), a mafor focus of pathologic changes in IPD, are discordant and controversial. The SNpc involvement is of critical importance for the elucidation of pathogenesis of IPD. Therefore, the neurodegeneration in SNpc was investigated in the experimental model of Mn neurotoxicity. Sprague-Dawley rats were administered with manganese chloride(1, 2, 5, 10 mg/kg/day, i.p.) for 30 days. Treated animals showed low levels of distance-traveled from locomotor activity tests. Ion chromatography revealed that Mn accumulation was significant in SN and basal ganglia in Mn-treated animals. Nissl staining showed neuronal loss of the striatum in all treated animals. The degree of neurodegeneration in SN was determined by immunohistochemical staining of tyrosine hydroxylase(TH). The numbers of TH-positive cells on nigral sections were not different from each groups(P>0.05). The densities of glial fibrillary acidic protein immunoreactivity from SN were similar between groups. TH-westen blotting showed no differences between treated animals and controls. In conclusion, the SNpc remains intact in Mn intoxication, and Mn-induced parkinsonism may be caused by damages of output pathways downstream to the nigrostriatal dopminergic system.

위발성 위장관 악성림프종 환자에서 항암치료의 효과

김찬규,신영록,김현정,배상병,이남수,이규택,박성규,원종호,홍대식,박희숙 순천향대학교 2006 Journal of Soonchunhyang Medical Science Vol.12 No.1

Purpose: The gastrointestinal (GI) tract is the most common site of extranodal non-Hodgkin's lymphoma (NHL), which is increasing in incidence, but there is no established optimal treatment modality. Thus, this study was investigated the clinicohistologic feature, the therapeutic modalities, and the prognosis for GI-NHL, as well as the factors affecting it. Methods: We retrospectively analyzed 45 patients who had been diagnosed as having GI-NHL and had been followed up from July 1994 to February 2005 at Soonchunhyang University Hospital. The patients were divided into groups according to the site of origin and to various other features, and the survivals of the various groups were compared. The modified Ann Arbor system and WHO classification were adopted for staging and histopathologic classification, respectively. Results: GI-NHL of the stomach, small bowel, ileocecal region, and colon occurred in 28 patients (62.2%), 5 patients (11.1%), 3 patients (6.7%), and 8 patients (17.8%), respectively, In one patient, the entire gastrointestinal tract was diffusely involved. The median age of patients was b5 years (25~78 years), and male-to-female ratio was 1:1.1. Fourteen patients were in stage Ⅰ, 24 in stage Ⅱ, 4 in stage Ⅲ, and 3 in stage Ⅳ. Surgical resection was performed in 19 patients, and combination chemotherapy was performed in 43 patients. Surgical resection only was performed in 4 patients, Chemotherapy only was performed in 26 patients. The expected overall 5 year survival of 45 patients was 39.6%, and there was a significant survival difference between the stages, but between sites of origin (p=0.842). The most important factors influencing the survival was the stage and other factors were not significant. Conclusion: The stomach was the most common site of GI-NHL. Most GI-NHL were localized Stage was the most important prognostic factor. However, Prospective randomized studies are needed to approve the therapeutic modality.

서울지역 여대생들의 떡에 대한 인식 및 섭취 실태 조사

김영순,오순덕,김향미,신지홍,김현경,배유미,조규영,조성환 高麗大學校 倂設 保健大學 保健科學硏究所 2003 保健科學論集 Vol.29 No.1

This study conducted a survey of the improvement and popularization for Korea Rice Cakes, a Korean traditional food, on two hundred women students in five colleges in Seoul, Korea. It was investigated to get the information of the recognition, preference, and consumption patterns for the succession and improvement of Korean Rice Cakes. The results are as follows: 1. A portion of 41.5% among responders knows from three to six kinds of Korean Rice Cakes, and of 28% can make at least one among the kinds of Korean Rice Cakes. 2. A portion of 91% recognizes that Korean Rice Cakes are one of well-nourished food, but of 42% answers that Korean Rice Cakes cannot be replaced with the principle food. Also, there are no significant differences in the recognition of Korean Rice Cakes as the kinds of religions. 3. The frequency of purchase is about one or twice in a month (35.5%). Consumers (36.5%) intend to purchase Korean Rice Cakes for the commemoration of national holidays or anniversaries. 4. The reasons for the preference of other foods more than Korean Rice Cakes are the easiness of purchase (36.0%), the deliciousness (21.5%), the diverse kindness (17.5%), and the proper package (9.5%). It is important that constant and particular school / home education is need to improve and success Korean Rice Cakes.

하안면부에서 입술의 돌출 정도와 안면 비대칭의 인지도에 관한 연구

김규선,김영진,이근혜,김영호,국윤아 대한치과교정학회 2006 대한치과교정학회지 Vol.36 No.6

교정 치료를 하고자 하는 가장 큰 동기 중의 하나는 좋은 안면을 얻고자 하는 것이므로 교정 치료 후 안면부에 나타나는 변화에 대한 환자들의 인지도를 이해하는 것은 교정 치료의 진단과 치료 계획 수립에 매우 중요한 일이다. 이에 본 연구는 정면 및 측모에서 하 안면부위의 입술의 위치와 안면 비대칭의 변화에 관하여 인지할 수 있는 최소한의 변화량을 알아보고자 균형 잡힌 비율을 지닌 가상의 정모와 측모 사진을 컴퓨터 영상으로 제작한 후 입술의 위치는 Ricketts의 E-line을 기준으로, 안면의 비대칭은 턱 끝의 중앙 지점을 기준으로 각각 1, 2, 3, 4 mm 변화시킨 디지털 영상을 이용하여 40명의 미술학도를 관찰자로 인지도 조사를 하였다. 연구 결과 환자가 입술의 위치와 비대칭의 변화를 인지하기 위해서는 측모에서 최소한 2 mm 이상, 정모에서 3 mm 이상의 변화가 필요하였으며 하 안면부 변화에 대한 인지도는 정모에서보다 측모 변화에 대한 인지도가 높았다. 또한 변화에 대한 사전 정보는 변화에 대한 인지율을 현저하게 높여 주었다. Objective: While one of the most prevailing motivations for seeking orthodontic treatment is to achieve good facial esthetics, understanding the level of a person's perception to the changes that have occurred on the face after orthodontic treatment is critical to the process of orthodontic diagnosis and treatment planing. Methods: 40 students attending art school participated in determining the level of their perception of changed lip position and facial asymmetry. Computer-graphic frontal face and facial profile photographs with balanced proportions were used to evaluate the level of a participant's perception of the changes in facial asymmetry and in lip position. Results: Change of lip position over 2 mm and over a 3 mm change of facial asymmetry was perceived significantly. Conclusion: The results indicated that at least a 2 mm change of lip position was needed to be perceived after orthodontic treatment. The level of perception of the change in facial asymmetry was lower than that of the change in lip position. Information about facial changes given prior to the evaluation enhanced the level of perception.

성인에서 장기간 Furosemide오용과 연관된 신수질 석회화

김윤구,이윤하,이규백,장세호,김대중,오하영,김보현,김미경,조윤숙 대한신장학회 1996 대한신장학회잡지 Vol.15 No.4

양성 갑상선 결절에서의 무수 알코올 치료 효과

김도희,나소영,이효진,홍우정,김군순,조영석,구본정,송민호,김영건,노흥규 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

목적 : 양성 갑상선 결절 환자에서의 PEI의 치료효과 및 부작용을 알아보고자 하였다. 방법 : 양성 갑상선 결절 환자 88명을 대상으로 초음파 소견에 따라 낭종성 결절, 복합성 결절, 고형성 결절 등 세 그룹으로 분류후 전체 및 각각에 대한 PEI의 치료효과 및 부작용을 조사하였다. 결과 : 양성 갑상선 결절 환자 88명을 PEI로 치료후 결절의 크기가 50%이상 감소한 경우는 전체 환자중 77.2%이었고 각 결절별로 살펴보면 고형성 결절에서 52.6%, 복합성 결절에서 72.4%, 낭종성 결절은 92.5%이었다. 부작용은 동통, 결절내 출혈, 감염, 결절의 누출등이 있었으나 대부분 무증상이었다. 결론 : PEI는 양성 갑상선 결절 환자증 적응증을 잘 살펴 고려해 볼 수 있는 치료법이라 생각되며 특히 낭종성 결절 환자에서 주사기에 의한 흡인후에 재발한 경우 일차적인 치료로 PEI를 고려해 볼 수 있겠다. Ultrasonography(US)-guided percutaneous ethanol injection (PEI) has been performed for the treatment of autonomous functioning thyroid nodules, thyroid cysts, & cold thyroid nodules. The author studied the efficacy of PEI in the treatment of benign cold thyroid nodules both solid and cystic (complex & pure). Eighty-eight euthyroid outpatients (age:44.2±13.9years, 75 women and 13 men) with benign cold thyroid nodules or simple thyroid cysts (69 with a single nodule and 19 with a prominent nodule within multinodular goiter) were includied in this study. After PEI, each subtype of thyroid nodules was divided into three groups in according to volume reduction complete response (90% or more of volume reduction), partial response (50% or more of reducton but below 90%), and failure (below 50% or increase in size) group. Overall response rates of PEI for benign thyroid nodules were complete 45(51.1%), partial 23(26.1%), failure 20(22.7%). In 20 cold solid nodules, complete response was observed in 6(30.0%), partial response in 5(25.0%), and failure in 9(45.0%). In 28 complex cysts, complete response was observed in 8(28.6%), partial response in 12 (42.9%), and failure in 8(28.6%). In 40 pure cysts, complete response was observed in 31(77.5%), partial response in 6 (15.0%), and failure in 3 (7.5%). Side effects comprised pain 8 (9.2%), intranodular bleeding 13 (14.6%), extracapsular leakage 1(1.1%), infection 1 (1.1%), increased size l(1.1%), and none 64(72.7%). PEI may prove a safe & effective tool for the therapy of cold thyroid nodules in selected cases and may be the treatment of choice of recurrent thyroid cysts. However, further investigation involving a larger number of patients and a longer follow-up is needed.