• 한국가스학회지
• /
• 제2권2호
• /
• pp.18-25
• /
• 1998

천연가스 배관에서 배관 두께는 ANSI B3l.8의 요건에 따라 내압에서 발생하는 원주방향응력으로부터 계산된다. 이외에도 매설배관에는 토양, 차량, 열팽창, 지반침하등도 작용되는데 이에 대한 평가가 필요하다. 매설가스배관에 걸리는 응력을 계산하는데는 두 가지방법이 있다. 첫째는 유한요소법(FEM)으로 배관형상이나 경계조건의 복잡함에 관계없이 응력을 계산할 수 있으나, 많은 비용과 시간이 걸린다. 두 번째는 수식을 이용하는 방법으로 매설가스배관의 응력을 계산하는 적절한 수식을 개발하여 배관설계와 안전성평가에 사용하고 있으나, 비전문가가 사용하고 이해하기에는 어려운 면이 많다. 본 연구에서는 여러 외부인자들이 매설 천연가스배관의 응력에 미치는 영향을 파악하기 위해 응력해석 비전문가가 쉽게 사용이 가능한 컴퓨터 프로그램을 개발하고자 하였다. 응력은 수식과 FEM에서 유도된 그래프에서 유추한 값으로 계산하였다. 전체논문은 두편으로, 본 논문에서는 우선 프로그램에 사용된 수식을 설명하였다.

• Applied Microscopy
• /
• 제39권3호
• /
• pp.253-260
• /
• 2009

상처치유는 growth factor와 cytokine들의 복합적인 작용에 의해 일어나는 과정이다. GM-CSF는 호중구와 대식세포를 분화시키고 각질세포를 증식시키는 다면발현성 사이토카인으로 여러 세포에서 재조합되어 사용되고 있다. (주)핸슨바이오텍에서 개발한 rice cell 유래의 재조합 rrhGM-CSF는 다른 세포에서 유래된 GM-CSF들보다 탄수화물 측쇄가 많은 것이 특징이다. rrhGM-CSF의 창상치유효과를 알아보기 위하여 햄스터에 만성 당뇨를 유도하여 상처치유가 어려운 동물모델을 만든 후, 등쪽에 인위적으로 피부 전 층을 제거하여 창상을 유발하였다. 실험군에는 rrhGM-CSF가 포함된 연고를 적용하고, 대조군에는 base cream만을 적용하여 재상피화되는 과정과 피부조직의 구조 및 PCNA 반응을 통한 세포증식 정도를 비교하였다. 육안 및 조직학적 관찰 결과, rrhGM-CSF를 적용한 그룹의 재상피화 속도가 더 빨랐으며, PCNA 면역조직화학적 조사에서도 증식하는 각질세포의 수가 대조군보다 상대적으로 많은 것으로 나타남으로써, rrhGM-CSF에 의한 피부상처 치유 효과를 관찰할 수 있었다. 이러한 결과들로 미루어 보아 벼세포 유래의 rrhGM-CSF는 국소적인 피부 창상 치유에 효과적인 것으로 보이며, rrhGM-CSF의 풍부한 당화 사슬은 이 단백질이 상처부위에 안정된 상태로 기능을 나타냄으로써 효과를 오랫동안 지속시킬 수 있었던 것으로 사료된다.

• Clinics in Shoulder and Elbow
• /
• 제12권2호
• /
• pp.126-136
• /
• 2009

목적: 견관절 자기 공명 영상에서 전방 및 외측 견봉 갈고리각을 측정하고 기존의 견봉 지표들과 비교하였다. 대상 및 방법: 2004년 6월에서 2005년 12월까지 수술을 통해 진단된 충돌증후군 환자를 대상으로, 동일한 시기에 충돌증후군 관련질환 이외의 원인으로 자기공명영상을 촬영한 대조군으로 선정하였다. 충돌증후군 환자군의 자기공명영상에 전방 견봉 갈고리각 (AAHA)과 측방 견봉 갈고리각 (LAHA), 그리고 견봉 갈고리지수 (AHI)를 측정하고 회전근개 파열환자군에 대해, 견봉형태, 견봉각, 전방덮임정도, 견봉경사, AAHA, 외측견봉각, 견봉염전각, 외측견봉굴곡각, LAHA, 외측덮임정도, 견봉상완거리, 견봉갈고리지수를 측정하여 대조군과 비교하였다. 결과: 충돌증후군 환자에서 단계가 진행할수록 AAHA, AHI는 증가하였다. 회전근개 파열환자에서 AAHA와 LAHA는 증가해 있었다. 단변량 분석에서는 견봉유형, 견봉각과 AAHA, LAHA, AHI가 회전근개 파열환자에서 대조군과 차이를 보였다. 다변량 분석에서는 성별, 연령, AAHA, 견봉각이 유의한 변수로 분석되었고 성별이 가장 큰 연관성이 있으며 연령, AAHA, 견봉각은 유사한 연관성을 보였다. 결론: 견봉의 형태는 사관상면의 특징이 회전근개 파열과 연관성을 가지므로 견봉성형술에서 견봉 측방 성형도 중요하다.

• Clinics in Shoulder and Elbow
• /
• 제17권2호
• /
• pp.64-67
• /
• 2014

Background: The purpose of this study was to determine whether in patients with rotator cuff tears a correlation exists between molecular changes and clinical parameters such as age, duration of symptom, range of motion, and tear size. Molecular changes of matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) were assessed by measuring messenger RNA (mRNA) levels of the two proteins. Methods: The rotator cuff tissue from was obtained from the edge of a torn tendon revealed after debridement by a motorized shaver. Using the sample of rotator cuff tissue, the reverse transcription polymerase chain reaction was performed to quantify MMP-2 and TIMP-2 mRNA expression. To determine whether mRNA levels and the clinical variables, such as age, defect size, range of motion (ROM) of shoulder, and duration of symptoms, show any correlation, Spearman's correlation coefficients were used to test for significant differences. Results: There was an inverse correlation between the mRNA levels of MMP-2 and TIMP-2 from the torn rotator cuff tendons regardless of the clinical variables. However, comparison of mRNA levels versus clinical parameters such as age, defect size, range of motion and duration of symptoms revealed a number of findings. We found a significant correlation between age and mRNA levels of MMP-2 from torn cuffs (r = 0.513, p = 0.021). Further, we found a significant correlation between defect size in the full thickness tears and mRNA levels of MMP-2 (r = 0.454, p = 0.045). Conversely, no significant association between mRNA levels of MMP-2 and ROM or duration of symptom was found. Conclusions: Our results suggest that both MMP-2 and TIMP-2 may be involved in the disease process of rotator cuff tears. Although the level of mRNA expression of MMP-2 and TMP-2 remain constant in torn rotator cuffs irrespective of the clinical variables, their levels may be influenced by age and defect size, which could account to change in tendon degradation and the healing process.

• 대한방사선기술학회지:방사선기술과학
• /
• 제20권2호
• /
• pp.49-55
• /
• 1997

This study was carried out to investigate radiographical and operating conditions of X-ray units and exposure doses to patients during chest radiography, so that the results could provide basic data used for reducing the exposure dose and for providing the diagnostic information with better quality. The conditions and exposure doses of 100 X-ray units mainly used for chest radiography were examined and also 100 radiological technologists mainly handling those apparatus at 76 medical facilities in Pusan were surveyed using a questionnaire from October 1 to December 31 in 1995. The following results were obtained from the study : 1. It was found that most units were capable of taking a high tube voltage radiography by showing 67% of the units equipped with the maximum tube voltage of 150 kV, 94% with more than 500 mA for the rating capacity and 85% with the full wave type of a signal phase. 2. For actual chest radiographical conditions, however, 80% of the units were operated at $60{\sim}100\;kVp$ and only 14% at 100 kVp and over for the high tube voltage. 3. The average exposure time was less than 0.1 second, and eighty four percent of the units adapted the X-ray tube currents ranging from 200 to 300 mA, 80% the focus-film distances between 180 and 210 cm, and 63% the focus sizes of more than 2.0 mm. 4. Most units(98%) employed additional filters made of aluminum, 75% the thickness of filters less than 2.0 mm, and only 2 units the compound filters. 5. Ortho chromatic system was only adopted in 13% of screen film system for the units, and 73% used the grid ratio at 8 : 1 for the low tube voltage during chest radiography. 6. The average exposure dose of all X-ray units during chest radiography was $371\;{\mu}Sv$ with a difference of about 16 times between the minimum to the maximum, and $386\;{\mu}Sv$ both at hospitals and at health centers, followed by $380\;{\mu}Sv$ at general hospitals and $263\;{\mu}Sv$ at university hospitals without showing any statistically significant differences. In conclusion, since patients during chest radiography at medical facilities in Pusan exposed to high levels of radiation, it is recommended that appropriate added filters and grids necessary for the high tube voltage radiography and high-speed screen systems should be adopted and used as soon as possible in order to reduce exposure dose to the patients.

• Archives of Plastic Surgery
• /
• 제38권5호
• /
• pp.576-584
• /
• 2011

Purpose: The shape and location, the amount of the wound and the characteristics of the remaining tissues are known to influence wound contraction. The previous studies using small animals have not been an appropriate model because the wound healing mechanisms and skin structures are different from those of the human. The purpose of this study is to evaluate wound contraction according to the shape and location of the wound using a $Micropig^{(R)}$. Methods: Four $Micropigs^{(R)}$ (Medikinetics, Pyeongtaek, Korea) that were 10 months of age weighed 25 kg were used. Full thickness skin defects were made by clearing all the tissues above the fascial layer in the shape of square, a regular triangle and a circle of 9 $cm^2$ each on the back around the spine. Eight wounds were created on the back of each pig, 50 mm apart from each other. The randomly chosen wound shapes included 11 squares, 11 regular triangles, and 10 circles. Wound dressing was done every other day with polyurethane foam. The wound size was measured using a Visitrak $Digital^{(R)}$ (Smith & Nephew, Hull, UK) on every other day after surgery from day 2 to day 28. A biopsy was performed on day 3, and 1, 2, 3 and 4 weeks to investigate the degree of acute and chronic inflammation, the number of microvesssel and myofibroblast density using H & E stain and immunohistochemistry. The wound contraction rate was calculated to figure out the differences among each of the shapes and the locations. Results: The ultimate shape of the circle wound was oval, and that of the regular triangle and square were stellate. The maximum contraction rate was obtained on 8 to 10 days for all the shapes, which corresponds with the immunohistochemical finding that myofibroblast increases in the earlier 2 weeks whereas it decreases in the later 2 weeks. Epithelialization was seen in the wound margin on day 7 and afterwards. The final wound contraction rates were highest for the regular triangle shapes; however, there were no statistically significant differences. The wound contraction rates by locations showed statistically significant differences. The wound in the cephalic area presented more contractions than that of the wounds in the caudal area. Conclusion: The location of a wound is more important factor than the wound shape in wound contraction.

• Archives of Plastic Surgery
• /
• 제37권6호
• /
• pp.721-725
• /
• 2010

Purpose: The survival of composite graft is dependent on three steps, (1) plasmatic imbibitions, (2) inosculation, and (3) neovascularization. Among the many trials to increase the survival rate of composite graft, prostaglandin E1 (PGE1) has beneficial effects on the microcirculatory level with vasodilating, antithrombotic, anti-inflammatory and neoangiogenic properties. Lipo-PGE1 which is lipid microspheres containing PGE1 had developed to compensate the systemic and local side effects of PGE1. This study was proposed to determine whether Lipo-PGE1 administration enhanced the survival of composite graft through neovascularization quantitatively in a rabbit ear model. Methods: Fourteen New Zealand White Rabbits each weighing 3~4 kg were divided in two groups: (1) intravenous Lipo-PGE1 injection group and (2) control group. A $2{\times}1\;cm$ sized, full-thickness rectangular composite graft was harvested in each auricle. Then, the graft was reaaproximated in situ using a 5-0 nylon suture. For the experimental group, $3{\mu}g$/kg/day of Lipo-PGE1 ($5{\mu}g$/mL) was administered intravenously through the marginal vein of the ear for 14 days. The control group was received no pharmacologic treatment. On the 14th postoperative day, composite graft of the ear was harvested and immunochemistry staining used Monoclonal mouse anti-CD 31 antibody was performed. Neoangiogenesis was quantified by counting the vessels that showed luminal structures surrounded by the brown color-stained epithelium and counted from 10 random high-power fields (400x) by independent blinded observer. Statistical analysis (Wilcoxon Signed Ranks test for nonparametric data) was performed using SPSS v12.0, with values of p<0.05 considered significant. Results: The mean number of the microvessels was $15.48{\pm}8.65$ in the experimental group and $9.82{\pm}7.25$ in the control group (p=0.028). Conclusion: The use of Lipo-PGE1 facilitated the neoangiogenesis, resulted in the improvement of the survival rate of graft. On the basis of this results, we could support wider application of Lipo-PGE1 for more effective therapeutic angiogenesis and successful survival in various cases of composite graft in the human.

• Archives of Plastic Surgery
• /
• 제37권4호
• /
• pp.323-328
• /
• 2010

Purpose: Adipose-derived stromal cells (ADSCs) are multipotent cells that have been found to promote wound healing through the process of angiogenesis and reepithelialization. Generally, it is well known that the antigenicity of ADSCs doesn't affect stem cell therapy. In this study, we investigated the effect of allogeneic ADSCs in the wound healing process by applying allogeneic ADSCs on the wound healing splint model of mice. Methods: Adipose tissue was harvested from the epididymal fat pads of BALB/c and C57BL/6 mice. Twenty four mice BALB/c were divided into three groups; control, isogeneic, and allogeneic groups. Two full thickness defects with 6 mm diameters were created on the back of BALB/c mice. $1{\times}10^6$ ADSCs from BALB/c mice were applied on the isogeneic group. In the allogeneic group, ADSCs from the C57BL/6 mice were applied. No cells were applied to the control group. The sizes of the wounds were evaluated in 3, 5, 7, 10, and 14 days after the wounds were applied, and tissues were harvested in 7 and 14 days for histological analysis. Results: Wound healing rates had showed significant increase in 10, and 14 days when the isogeneic group was compared to the control group, but the allogeneic group showed significantly decrease compared to the isogeneic group (p<0.05). Histological scores in the isogeneic group were significantly high, but significantly lower in the allogeneic group when compared to the isogeneic group in 2 weeks (p<0.05). In the isogeneic group, thick inflammatory cell infiltration with abundant capillaries were observed in 1 week, and thick epithelium with many large capillaries were observed in 2 weeks. Conclusion: When isogeneic ADSCs were applied to wounds, they presented a faster wound healing rate compared to controls and the allogeneic group. Unlike general stem cell therapy, these findings suggest that cell therapy targeted at enhancing wound healing may benefit from the use of ADSCs with identical antigenicity, as opposed to allogeneic or xenogenic ADSCs.

• Journal of Trauma and Injury
• /
• 제20권1호
• /
• pp.52-56
• /
• 2007

Marjolin's ulcer is a rare and often-aggressive cutaneous malignancy that arises in previously traumatized or chronically inflamed skin, particularly after burns. We experienced two cases after burns. Case I involved a forty eight year-old man who had suffered from a flame burn at the parietal scalp area, where had been initially described three years earlier as a full-thickness wound including the pericranium. The man consulted us for a persistent ulcerative and infected wound on the burned lesion during the last 24 months, which turned out on the contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) to be the squamous cell carcinoma with involving the skull and the dura mater. Although the posterior auricular lymph node was enlarged on the ipsilateral side, recent positron emission tomography (PET) CT did not show any metastatic lesion. It was impossible for us to resect the intracranial involvement of the tumor radically, and the postoperative PET CT still showed a focal fluorodeoxyglucose (FDG) uptake around the wall of the superior sagittal sinus. We think that an aggressive combined approach is essential for treatment in early stages for a high success rate, before the intracranial structures are involved because there is no consensus on the treatment for advanced disease, and the results are generally poor. Case 1 also did not involve a radical resection because of the intracranial invasion to the wall of superior sagittal sinus and the possibility of damage to the major cortical veins. He received adjuvant radiotherapy and must be followed periodically. Case 2 involved an eighty six year-old women who suffered from a painful scalp ulcer lesion after flame burns three years earlier. Unlike case 1, neither tumor infiltration into the dura nor lymph node enlargement was observed on the contrast-enhanced computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET) CT. We did a radical resection of the tumor, including the involved bone, and a cranioplasty with bone cement.

• 한국축산시설환경학회지
• /
• 제5권3호
• /
• pp.157-170
• /
• 1999

This study was conducted to investigate the effects of Scoria, Quartz porphyry and Oak charcoal powder feeding by 1% level of concentrate on the fattening cross bred bulls(5/8 Korean Native Cattle, 2/8 Charolais, 1/8 Brahman germ plasma) Feeding trial was conducted with 4 treatment groups which were T1(Full feeding of concentrate and roughage for 12 months), T2(T1 and Scoria addition), T3(T1 and Quartz porphyry addition) and T4(Oak charcoal addition) for 360 days, consisting of 32 heads whose initially weights were about 299.7kg. The results obtained are summarized as follows; 1. During the over-all period, average daily gains by T3, T4, T2 and T1 were 1.024, 0.987, 0.977kg and 0.964, respectively, without a significant difference by treatments. 2. Concentrate intakes per body weight and TDN intakes required per unit of kilogram gain were lower in addition agent groups than in control, and in all the treatments feed efficiency was higher at early stage for 360 fattening day than at end stage. 3. Carcass weight, dressing percent, back-fat thickness and loin eye muscle area by treatments were 330.9 to 348.4kg(average 340.3kg), 55.2~56.2(average 55.8%), 0.41~0.55(average 0.46cm)and 76.0~80.9$\textrm{cm}^2$(average 77.6$\textrm{cm}^2$), respectively, and were improved in addition agent groups than in control. 4. Meat quality grade is higher in addition agent groups than in control, and heads of 1st grade by treatments was 3, 2, 1 and none in T4, T2, T3 and T1, respectively. 5. Incidence heads of diseases by treatment were not apparently different, but diseases of digestive system was decreased in addition agent groups than in control. 6. The nitrate nitrogen content of fattening bull dung which collected in rectum were 0.082~0.089% (average 0.084%), and the content in addition agent groups was smaller than in controll. 7. Income was higher in order of T4, T3, T2, and T1 and incomes of treatment groups were grater than that of control group by 21.4 to 33.5 percent. According to the above results it may be concluded that fattening bulls may be required to feed no more than 1% of Scoria, Quartz porphyry and Oak charcoal powder based on the concentrate feeding level during the fattening period(12 to 24 month of age) to produce high quality meat and increase income.