NR과 SBR 가황물의 경도와 강성도에 대한 온도의 영향

진현호 ( Hyun Ho Jin ),홍창국 ( Chang Kook Hong ),조동련 ( Dong Lyun Cho ),강신영 ( Shin Young Kaang ) 한국고무학회 2007 엘라스토머 및 콤포지트 Vol.42 No.3

본 연구에서는 고무제품의 수치 안정성과 성능유지에 직접적으로 영향을 미치는 중요한 특성 중 하나인 온도변화에 따른 고무재료의 경도변화를 고찰하였다. 새롭게 제작된 International Rubber Hardness Degree(IRHD, Normal type) 경도측정 시험기를 사용하여 미충전된 NR과 SBR시편의 여러 온도에서 경도변화를 측정하였으며 Young`s modulus 값과 비교하였다. NR과 SBR 모두 유리전이온도 근처에서 경도와 Young`s modulus의 급격한 변화를 보였다. 온도가 증가함에 따라 경도와 Young`s modulus 값이 증가하는 경향을 보였으며 이는 분자의 운동성과 엔트로피 영향으로 해석할 수 있다. 카본블랙과 실리카가 충전된 NR과 SBR의 경우 충전제의 함량이 증가함에 따라 경도에 미치는 온도의 영향이 감소함을 관찰하였다. Hardness of rubbery materials, which is important for dimensional stability and product performance, was investigated upon temperature change in this study. A newly developed IRHD (International Rubber Hardness Degree) tester was used to measure the hardness changes of NR and SBR specimens at various temperatures and the hardness values were compared with the Young`s modulus. The hardness and Young`s modulus of NR and SBR showed an abrupt change near the glass transition temperatures. The hardness and Young`s modulus were increased by increasing temperature due to the increased random chain conformation of molecules. The effect of temperature on hardness and Young`s modulus of NR and SBR specimens filled with carbon black and silica was decreased by increasing filler content.

Long second toe: its nail and skin changes

( Geun-hwi Park ),( Woo-il Kim ),( Min-young Yang ),( Won-ku Lee ),( Tae-wook Kim ),( Sung-min Park ),( Hyun-joo Lee ),( Gun-wook Kim ),( Hoon-soo Kim ),( Hyun-chang Ko ),( Byung-soo Kim ),( Moon-bum 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.2

Background: Nail can be affected by trauma, infection, and systematic disorders. In particular, the toe nails are exposed to the repeated and cumulative minor traumas, which usually result in thickened, splitted, and discolorated nails. Considering these, it can be inferred that the long second toe can be related to various nail and skin changes by repeated minor traumas such as friction in shoes, but the study or report on this topic hasn’t been done yet. Objectives: The purpose of this study was to introduce various nail and skin changes on long second toe. Methods: We analyzed the kinds of nail/skin changes of 50 patients with long second toe, enrolled at Pusan National University Hospitals (Busan and Yangsan) from 2013 to 2018. Results: There was no significant difference in the incidence of left and right toe and toenail, and 7 (14%) patients presented bilateral distribution. The most common nail change on long second toe was melanonychia (23, 46%), followed by subungual hematoma (15, 30%), onycholysis (2, 4%), subungual hyperkeratosis (2, 4%), onychomadesis (1, 2%), and retronychia (1, 2%). The most common skin change was corn (9, 18%), followed by paronychia (2, 4%). Twenty (20/50, 40%) patients also had other toe or toenail changes. Among them, the most common site was big toe/nail (13, 62%), and the most common change was subungual hematoma (8, 42%). Conclusion: Through this study, the dermatologists can recognize and diagnose the nail and skin changes of long second toe.

Rat의 복강내에 투여한 5-fluorouracil-polyglycolic acid 제형이 장기에 미치는 영향에 관한 연구

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

For more effective intraperitoneal chemotherapy, the authers made 5-fluorouracil-polyglycolic acid composite disks(FU-PGA disks) with 5-fluorouracil and polyglycolic acid, a biodegradable polymer. We inserted the FU-PGA disk into the peritoneal cavites of Sprague-Dawley male rats, the control and three experimental groups; one FU-PGA disk insert group(300mg/kg), two FU-PGA disk insert group(600mg/kg), and three FU-PGA disk insert group(900mg/kg). The control group received a similar number of PGA disk inserts. A pharmacokinetic study was performed to measure the 5-fluorouracil concentration in the peritoneal fluid, blood, and tissues(liver, kidney and heart) at 24 hours, 72hours and 168 hours after insertion of the FU-PGA disk. Light and electron microscopic studies were done. The results were as follows: 1) The number of white blood cells and platelets decreased after FU-PGA insertion. The degree was proportional to the duration and amounts inserted. The change in the number of red blood cells varied slightly. 2) Light microscopically, slight changes were noted at 168 hours in the 3 disk insert group (900mg/kg). Mild fatty change and hepatocyte degeneration around the central veins of the liver were noted, with vacuolar degeneration in the proximal convoluted tubules of the kidney. 3) Electron microscopically,the liver showed focal increases of lipid droplets in the hepatocytes, and irregular nuclear membrane with focal nucleolar segregation of the fibrillar and granular elements. Also the double membranous structure of the hepatocytes and Kupffer cells was widened with bleb formation. The kidney showed wide separation of the nuclear double membrane in the proximal convoluted tubular cells and mesangial cells, with vacuolation and myelin figure formation in the mitochondria of the proximal convoluted tubular cells, at 72 hours and 168 hours in the 2 to 3 FU-PGA insert groups. The heart showed focal loss of cristae,vacuolation and myelin figure formation in the mitochondria of the 2 to 3 FU-PGA insert groups. In conclusion, despite the large amont of FU-PGA inserted, the histopathological changes in the liver, kidney and heart were slight, and consonant with the very low amount of 5-fluorouracil concentrations detected in the liver, kidney and heart. The above results suggest that the FU-PGA composite can serve as a new device for releasing drugs in a controlled manner and easily targeted to intraperitoneal organs. This device can improve the efficacy of intraperitoneal chemotherapy for gastric cancer.

보조호르몬요법을 받는 여성 유방암 환자의 모발 변화와 치료 실태에 대한 기초 연구

이재경 ( Jae Kyung Lee ),김창현 ( Chang-hyun Kim ),홍동균 ( Dongkyun Hong ),정경은 ( Kyung Eun Jung ),서영준 ( Young-joon Seo ),김창덕 ( Chang-deok Kim ),이진선 ( Jin Sun Lee ),권인선 ( In Sun Kwon ),박상현 ( Sanghyun Park ),이영 대한피부과학회 2021 대한피부과학회지 Vol.59 No.7

Background: Hormone therapy, which includes tamoxifen and aromatase inhibitors, is the most common adjuvant therapy used for breast cancer. However, only a few studies have reported endocrine therapy induced alopecia. Objective: We investigated the effects of long-term adjuvant hormone therapy on hair in patients with breast cancer, in addition to patients’ concerns and current treatment for hair loss. Methods: Patients completed a questionnaire that included information on self-perceived hair changes after each adjuvant therapy session, distress, and current treatment for hair loss. Using a folliscope, we measured hair density and thickness in each patient and in healthy controls. Results: The study included 93 patients with breast cancer (mean age 51.9±9.8 years). The density and hair thickness were 106.36±21.85 hairs/cm2 and 0.07±0.01 mm in the patient group and 147.86±30.67 hairs/cm2 and 0.07±0.01 mm in the control group (n=98, mean age 52.10±8.40 years), respectively. The mean hair density was significantly lower in the patient group than in the control group; however, no statistically significant intergroup difference was observed in hair thickness. Among 76 patients who perceived hair changes after adjuvant therapy, 71.1% (n=54) were distressed with regard to hair changes. However, only 7.8% of the patients, including two who were treated by dermatologists, currently received treatment for hair changes. Conclusion: Dermatologists should be familiar with hair changes in patients with breast cancer and provide appropriate education to encourage patients to consult dermatologists for hair loss and thinning after breast cancer treatment. (Korean J Dermatol 2021;59(7):521∼526)

실험적 진폐증에서 투여약제에 따른 면역학적 병리학적 조직변화

윤임중,임현우,노영만,오상용,정장영,임영,김경아 가톨릭 대학 산업의학 쎈타 산업의학연구소 1993 韓國의 産業醫學 Vol.32 No.2

To access the effects of some drugs such as piperazine phosphare, azathioprine and allopurinol in the experimental pneumoconiosis, 263 rats weighted 240-320 gm was divided into the control and eight experimental groups. To each group, the turbid solution mixed free silica, talc and natural coal dust of 50 mg in 0.8 ml saline were instilled intratracheally. At the begining and 5th week of experiment, piperazine phosphate(8mg/week orally), aspirin(1.5mg/day intramuscularly), azathioprine(25mg/day orally) and allopurinol(1.5mg/day orally) were administered simultaneously, while the dust turbid solution was only given to the control group. For each group the change of body weight. dry right lung weight, cellularity including total cell, macrophage, lymphocyte and neurtrophil in bronchoalveolar lavage fluid, superoxide ion, hydroxyproline, leukotriene B₄, tumor necrotsis factor, prostaglandin E₂were examined, and observed the pathological chages in lung tissue. The results were as follow : 1. The larger amount of their instilled dust and the longer observation period, the severer pathological findings were found in the lung tissue of each experimental group. 2. The body and dry right lung wight was not significantly changed in the experimental groups compared with the control group. 3. The number of total cell in bronchoalveolar lavage fluid was markedly less in the experimental group than the control one, while no significant difference was found in the percent alveolar macrophages and lymphocytes in both groups. However, the percent of neutrophiles was usually lower than in the control group. 4. The amount of superoxide ion was frequently less in the experimental group compared with the control one. 5. The amount of hydroxyproline was significantly lower in the experimental group than in the control one. 6. The amount of leukotriene B₄was usually less in the drug administered group than in the control one. 7. The amount of tumor necrotic factor was also frequently lower in each experimental group than in the control one. 8. The amount of prostaglandin E₂was usually higher in each experimental group than in the control one.

A New MPEG-2 Rate Control Scheme Using Scene Change Detection

Park, Sang-Gyu,Lee, Young-Sun,Chang, Hyun-Sik Electronics and Telecommunications Research Instit 1996 ETRI Journal Vol.18 No.2

We propose two new rate control schemes to improve MPEG-2 rate control in view of visual quality when scene changes happen. Two proposed schemes are characterized by real-time and non real-time improvement to reduce the impact of scene changes. We also propose a new target-bit prediction method using spatial activity of pictures and present a simple and efficient scene change detection scheme using signed difference of mean absolute difference (MAD). Computer simulation results show that the proposed real-time algorithm effectively alleviates visual quality degradation after scene changes. The proposed non real-time algorithm gives maximum 2 dB improvement in peak signal-to-noise ratio (PSNR) at a scene-changed picture, compared with MPEG-2 rate control scheme and it shows better quality than the real-time one.

공공병원의 생산성 변화와 결정요인 분석

양동현(Yang, Dong-Hyun),장영재(Chang, Young-Jae) 대한경영학회 2011 大韓經營學會誌 Vol.24 No.6

급성 췌장염으로 발현된 낭성 변화를 이릉킨 종격동 부갑상선 선종 1예

이준호,최영식,박진홍,허갑도,윤설영,최소진,권태헌,이창렬,손성표,박영효 대한내분비학회 1998 Endocrinology and metabolism Vol.13 No.3

Hypercalcemia due to hyperparathyroidism is rarely associated with acute pancreatitis. But, the relationship between hypercalcemia and pancreatitis still remains controvesial. Ectopic parathyroid adenoma with cystic change is one of the rare causes of hyperparathyroidism, and is usually located in neck and mediastinum. We report a case of mediastinal parathyroid adenoma with cystic change associated with acute pancreatitis. A 54-year-old male presented with epigastric pain for 3 days. The serum calcium, phosphate, elastase were 16.8mg/dL, 1.1 mg/dL, 2772.0 ng/mL respectively and his parathyroid hormone level in serum was 651.84 pg/mL. Chest CT showed a mediastinal mass with well defined inhomogenously enhanced density located between SVC and aorta. The patient was diagnosed to hyperparathyroidism with acute pancreatitis due to mediastinal parathyroid adenoma with cystic change, and was surgically removed. The surgical biopsy showed parathyroid adenoma with cystic change. After operation his general condition was improved and serum calcium, phosphate, amylase, lipase level were normalized (J Kor Soc Endocrinol 13:473-479, 1998).

암세포 증식에 대한 YB-1 안티센스 올리고핵산염의 영향

김명성 ( Myung Sung Kim ),이완식 ( Wan Sik Lee ),박창환 ( Chang Hwan Park ),주영은 ( Young Eun Joo ),김현수 ( Hyun Soo Kim ),최성규 ( Sung Kyu Choi ),유종선 ( Jong Sun Rew ),정영도 ( Young Do Jung ),김세종 ( Sei Jong Kim ),안봉환 대한내과학회 2006 대한내과학회지 Vol.71 No.3

목적: YB-1은 PCNA, DNA 중합효소 및 MDR 유전자 등의 전사인자로 작용한다. YB-1 유전자는 정상 어른의 간에서는 발현되지 않지만 태아의 간이나 재생 중인 간에서는 발현이 현저히 증가되어서 세포의 증식과 밀접한 관련이 있음이 보고되었다. 본 연구에서는 YB-1 유전자의 안티센스 올리고핵산염을 이용하여 YB-1의 발현을 억제함으로써 암세포 증식을 차단 할 수 있는지를 실험하고 암치료를 위한 유전자 요법으로서의 가능성을 알아보았다. 방법: 세포주로는 Chang liver, HepG2, CT-26 세포를 사용하였고, 사람의 정상세포로는 섬유아세포와 내피세포가 혼재된 조직을 사용하였다. YB-1 유전자의 안티센스 올리고핵산염으로는 YB-1 cDNA의 변역 시작 부위에 상보적인 21mer 올리고핵산염을 제작하여 사용하였다. 세포의 성장은 MTT assay를 이용하였고, 유전자 발현은 Northern blot으로 분석하였으며, 세포주기 변화는 propidium iodide로 염색하여 유식세포분석기로 분석하였다. 동물실험에서는 CT-26 세포를 1.0×10(5)개씩 Balb/c 생쥐의 피하에 접종하여 종양을 유도하였다. 종양이 유도된 Balb/c 생쥐에 YB-1 안티센스 올리고핵산염을 꼬리정맥이나 종양조직에 주사한 후 종양의 크기를 측정하여 종양억제 효과를 관찰하였다. 결과: YB-1 안티센스 올리고핵산염은 CT-26 세포에서는 50 nM 이상 농도에서 Chang liver와 HepG2 세포에서는 10 nM 이상 농도에서 세포주의 성장을 강하게 억제하였지만 정상 조직세포의 성장에는 아무런 영향을 미치지 않았다. 안티센스 올리고핵산염을 DOTAP에 담지한 경우 세포성장 억제에 미치는 효과가 안티센스 올리고핵산염 단독 처치 보다 강하였다. 이때 YB-1의 발현은 증식이 억제된 세포주(Chang liver 및 CT-26)에서는 감소하였으나 정상조직세포에서는 변화가 없었다. 증식이 억제된 세포주에서 세포주기를 살펴보면 초기에 S phase가 감소함을 관찰 할 수 있었다. 꼬리정맥이나 종양조직에 YB-1 안티센스 올리고핵산염을 주입 시 종양의 크기가 유의하게 감소하였다. 결론: 이상의 실험 결과 YB-1 안티센스 올리고핵산염은 암세포의 성장을 저해하며 종양 동물모델에서 종양의 성장을 억제할 수 있음을 시사하였다. Background: Human YB-1 is a transcription factor that binds to the inverted CCAAT box in the promoter region of a variety of genes such as PCNA, DNA polymerase and MDR. In this study we evaluated the effect of YB-1 antisense oligonucleotides on tumor cell growth. Methods: Chang liver, HepG2 and CT-26 cells were cultured as immortalized cell lines. The MTT (3-[4,5-dimethylthiazol-2-yl] 2,5-diphenyltetrazolium bromide) assay, Northern blot and flow cytometric analyses were used to determine cell growth, gene expression and cell cycle changes. In an animal model, CT-26 cells were injected into Balb/c mice to induce tumor; YB-1 antisense oligonucleotides were injected into the tail vein or tumor tissue of the mice; change of tumor size was then measured. Results: Phosphorothioated YB-1 antisense oligonucleotides suppressed the proliferation of the immortalized liver cells (Chang liver cells) and a variety of cancer cells (HepG2 and CT-26 cells); however, it did not inhibit normal cell growth. The DOTAP/antisense oligonucleotide mixture showed stronger effects on cell proliferation than did the antisense oligonucleotide alone. The YB-1 antisense oligonucleotide decreased specific expression of the YB-1 mRNA in the immortalized cancer cell lines. Flow cytometric analysis revealed that the inhibition of cell proliferation might have been due to a decrease in the S phase of the cell cycle. We found that in an animal tumor model, the administration of the YB-1 antisense oligonucleotide, in the vein or tumor tissues, decreased the tumor size significantly. Conclusions: These results suggest that the YB-1 antisense oligonucleotide may inhibit growth of a variety of cancer cells.(Korean J Med 71:293-301, 2006)

제 1 소구치·발치가 수반된 Class Ⅰ 전돌 증례의 치료 전후 변화

장영일,이유현 대한치과교정학회 1996 대한치과교정학회지 Vol.26 No.5

본 연구는 제 1 소구치 발치로 양호하게 치료된 Class I 전돌 환자의 치료 전 안모 골격 특성과 치료 전후 변화를 조사하여 Class I 전돌 환자의 치료 계획 수립에 이용하고자 하였다. 서울대학교 병원 치과 진료부 교정과에 내원하여 치열궁 길이 부조화의 양이 7.00mm를 넘지 않고 Class I 전돌 환자로 진단되어 상, 하악 제 1 소구치를 발거한 후 동일한 임상가에 의하여 동일 치료 기법으로 양호하게 치료된 환자 35명 (여자 27명, 남자 8명)을 대상으로 치료 전후 측모 두부 방사선 사진을 계측하여 다음과 같은 결과를 얻었다. 1. 치료 전후 골격 형태는 크게 변하지 않았고 치열, 치조골, 연조직에서 치료 후 유의성 있는 변화가 있었다. 2. 치료 전 골격 형태는 SN-GoGn이 36.56°, AB-MP이 66.92°, ODI가 69.17°, APDI가 81.31°, CF 150.52°로서 수직적인 부조화 경향을 보였다. 3. 치료 전 치열 형태는 절치간 각이 113.11°, U1 to FH가 117.78°, L1 to A-Pog이 7.94mm였으며 연조직 측모상 E line에 대하여 상순이 2.88mm, 하순이 5.43mm 돌출되어 있었다. 4. 치료 후 치열 형태는 절치간 각이 14.46° 증가되었으며 연조직 측모상 E line에 대하여 상순이 2.45mm, 하순이 3.2mm 후방이동되었다. (P<0.001) 5. 치료 전 발치 지수 (EI)는 138.71이었고 치료 후 EI는 148.2였다. The purpose of this study was to evaluate the dentofacial characteristics and the post treatment dentofacial changes of those treated by four premolar extractions and to investigate the factors affecting extraction decision. The sample consisted of 35 patients (27 females, and 8 males) with no more than 7.0mm crowding, diagnosed as Class I protrusion. Pre-treatment and post-treatment lateral cephalograms were evaluated. Computerized statistical analysis was carried out using SPSS/PC+ program. The results were as follows. 1. There was no significant change in skeletal pattern after treatment while there was significant change in dentoalveolar and soft tissue pattern. 2. In pre-treatment skeletal pattern, a tendency toward vertical discrepancy was found. 3. In pre-treatment dental pattern, interincisal angle was 113.11°, U1 to FH was 117.78° and L1 to A-Pog was 7.94mm. Pre-treatment upper and lower lip position was 2.88mm and 5.43mm to E line. 4. After treatment, interincisal angle increased 14.46° and upper and lower lip moved back 2.45mm and 3.2mm to E line. (p<0.001) 5. The EI was 138.71 before treatment and 148.2 after treatment.