• Title/Summary/Keyword: Fractures

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Groundwater Flow Modeling in a Block-Scale Fractured Rocks considering the Fractured Zones (단열대의 영향을 고려한 블록 규모 단열 암반에서의 지하수 유동 모의)

  • Ko, Nak-Youl;Ji, Sung-Hoon;Koh, Yong-Kwon;Choi, Jon-Won
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.8 no.2
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    • pp.159-166
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    • 2010
  • The block-scale groundwater flow system at Olkiluoto site in Finland was simulated. The heterogeneous and anisotropic hydraulic conductivity field for the domain was constructed from the discrete fracture network, which considered only the fractured zones identified in the deep boreholes installed in the study site. The groundwater flow model was calibrated by adjusting the recharge rate and the transmissivities of the fractured zones to fit the calculated hydraulic heads and into- and out-flow rates in the observation intervals of the boreholes with the observed ones. In the calibrated model, the calculated flow rates at some intervals were not in accordance with the observed ones although the calculated hydraulic heads fit well with the observed ones, which revealed that the number of the conduits for groundwater flow is insufficient in the conceptual model for groundwater flow modeling. Therefore, it was recommended that the potential local conduits such as background fractures should be added to the present conceptual model.

The Effect of Nasal Packing with Rolled Silastic Sheet after Closed Reduction of Nasal Bone Fracture (비골 골절 교정 후 Rolled Silastic Sheet를 이용한 비강 충진의 효과)

  • Son, Kyung-Min;Yang, Jeong-Yeol;Kim, Gyu-Bo;Han, Yun-Ju;Cheon, Ji-Seon
    • Archives of Plastic Surgery
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    • v.38 no.5
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    • pp.602-608
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    • 2011
  • Purpose: Nasal bone fracture is the most common type of facial bone fracture and most of nasal bone fracture is combined with septal fracture frequently. Nasal septum is important to support the distal nose and to maintain the nasal airway. But nasal septal fractures are usually unrecognized and untreated at the time of operation. Recently, various materials were using for nasal packing after closed reduction, however these materials are not focused on the correction of nasal bone and nasal septal fracture and many patients are suffered from nasal packing materials. Thus, the purpose of this study is to compare routine packing materials and rolled silastic sheet with respect to postoperative effect of correction of nasal bone fracture and discomfort of nasal packing materials. Methods: We examined 320 patients treated nasal bone fracture from January 2008 to December 2010. For Group I (n=92), $Merocel^{(R)}$ was used for nasal packing, for Group II (n=152) vaseline gauze was used, and Rolled silastic sheet (RSS) with vaseline gauze packing (VGP) was used for Group III (n=76). Under the general anesthesia, all patients were operated by closed reduction and nasal packing was done using three kinds of packing materials. At the time of postoperative 7 days, packing material was removed and studied for pt's satisfaction and postop. complications. Results: In patients with RSS with VGP, the complaints (nasal obstruction, foreign compressive sensation and discomfort during food ingestion) of keeping the nasal packing were decreased ($p$ <0.05) and the postoperative complication (deviation) were decreased comparing to vaseline gauze packing and $Merocel^{(R)}$ packing, however, these differences were not statistically significant ($p$ >0.05). Conclusion: Postoperative nasal packing with RSS with VGP was more comfortable to the patients and it was more effective method to correct the nasal bone fracture and nasal septal fracture.

CT Observation of Alloplastic Materials Used in Blow Out Fracture (안와골절 정복술에 사용된 인공삽입물의 전산화단층촬영 추적관찰)

  • Lee, Won;Kang, Dong-Hee
    • Archives of Plastic Surgery
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    • v.37 no.4
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    • pp.380-384
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    • 2010
  • Purpose: Distinguishing different types of implants and assessing the position and size of implants by radiologic exam after orbital wall reconstruction is important in determining the surgery outcome and forecasting prognosis. We observed time-dependent density changes in three types of implants (porous polyethylene, resorbing plate and titanium mesh plate) by performing facial bone CT after orbital wall reconstructions. Methods: A total of 32 patients, who had underwent orbital wall fracture surgery from October 2006 to March 2009 and received facial bone CT as outpatients at 1 postoperative year were included in the study. Follow-up facial bone CT was performed on the patients pre- operatively, 1 month post-operatively, and 1 year post-operatively to observe the status of the orbital implants. Medpor $^{(R)}$ (Porex Surgical, Inc., Newnan, Ga.) was used as porous polyethylene and followed-up in 14 cases; for resorbing plate, Synthes mesh plate (Synthes, Oberdorf, Switzerland) was used in the reconstruction, and followed-up in 11 cases; and titanium mesh plate usage was followed-up in 7 cases. Computed tomographic scan (CT) and water's view were done for radiography, and hounsfield unit (HU) was used to compare density of those facial bone CT. Wilcoxon signed rank test was applied to statistically verify measurement difference in each group of hounsfield units. Results: Facial bone CT examination performed in 1 month post-operative showed that the density of porous polyethylene, resorbing plate and titanium mesh plate were -42.07, 105.67 and 539.48 on average, respectively. Among the three types of implants, titanium mesh plate showed the highest density due to its radiopaque feature. Following up the density of three types of implants in CT during 1 year after the orbital wall fracture surgery, the density of porous polyethylene increased in 10.52 House Field Units and the resorbing plate was decreased in 26.87 HouseField Units. There were no significant differences between densities in 1 month post-operatively and 1 year post-operatively in each group ($p{\geq}0.05$). Conclusion: We performed facial bone CT on patients with orbital fractures during follow-up period, distinguishing the types of implants by the different concentration of implant density, and the densities showed little change even at 1 year post-operative. To observe how implant densities change in facial bone CT, further studies with longer follow-up periods should be carried out.

Perioperative Orbital Volume Change in Blowout Fracture Correction through Endoscopic Transnasal Approach (안와파열골절의 비강내 내시경적 접근을 통한 교정에서 수술 전후 안와 용적 변화)

  • Lee, Jae Woo;Nam, Su Bong;Choi, Soo Jong;Kang, Cheol Uk;Bae, Yong Chan
    • Archives of Plastic Surgery
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    • v.36 no.5
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    • pp.617-622
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    • 2009
  • Purpose: Endoscopic transnasal correction of the blowout fractures has many advantages over other techniques. But after removal of packing material, there were some patients with recurrence of preoperative symptoms. Authors tried to make a quantitative anterograde analysis of orbital volume change over whole perioperative period which might be related with recurrence of preoperative symptoms. Methods: 10 patients with pure medial wall fracture(Group I) and 10 patients with medial wall fracture combined with fracture of orbital floor(Group II) were selected to evaluate the final orbital volume change, who took 3 CT scans, pre-, postoperative and 4 months after packing removal. By multiplying cross - section area of orbit in coronal view with section thickness, orbital volume were calculated. Then, mean orbital volume increment after trauma, mean orbital volume decrement after endoscopic correction and volume increment after packing removal were found out. And we tried to find correlations between type of fracture, initial correction rate and final correction rate. Results: The mean orbital volume increment of the fractured orbits were 7.23% in group I and 13.69% in group II. After endoscopic surgery, mean orbital volume decrement were 11.0% in group I and 12.46% in group II. Mean volume increment after packing removal showed 3.10% in group I and 6.50% in group II. The initial correction rate(%) showed linear correlation with final correction rate(%) after packing removal. And there were negative linear correlation between increment percentage of orbital volume by fracture and final correction rate(%). Conclusion: Orbital volume was proved to be increasing after removal of packing or foley catheter and it was dependent upon type of fracture. Overcorrection should be done to improve the final result of orbital blowout fracture especially when there are severe fracture is present.

A Numerical Study on the Progressive Brittle Failure of Rock Mass Due to Overstress (과지압으로 인한 암반의 점진적 취성파괴 과정의 수치해석적 연구)

  • Choi Young-Tae;Lee Dae-Hyuck;Lee Hee-Suk;Kim Jin-A;Lee Du-Hwa;You Kwang-Ho;Park Yeon-Jun
    • Tunnel and Underground Space
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    • v.16 no.3 s.62
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    • pp.259-276
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    • 2006
  • In rock mass subject to high in-situ stresses, the failure process of rock is dominated by the stress-induced fractures growing parallel to the excavation boundary. When the ratio of in situ stresses compared to rock strength is greater than a certain value, progressive brittle failure which is characterized by popping and spatting of rock debris occurs due to stress concentration. Traditional constitutive model like Mohr-Coulomb usually assume that the normal stress dependent frictional strength component and the cohesion strength component are constant, therefore modelling progressive brittle failure will be very difficult. In this study, a series of numerical analyses were conducted for surrounding rock mass near crude oil storage cavern using CW-FS model which was known to be efficient for modelling brittle failure and the results were compared with those of linear Mohr-Coulomb model. Further analyses were performed by varying plastic shear strain limits on cohesion and internal friction angle to find the proper values which yield the matching result with the observed failure in the oil storage caverns. The obtained results showed that CW-FS model could be a proper method to characterize essential behavior of progressive brittle failure in competent rock mass.

A Clinical Analysis of 24 cases of Cardiac Contusion and Cardiac Concussion (둔상에 의한 심타박상과 심좌상의 임상적 고찰)

  • 이계선;정진악;금동윤;안정태;이재원;신제균
    • Journal of Chest Surgery
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    • v.32 no.3
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    • pp.270-275
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    • 1999
  • Background: In the patients with thoracic injury, we suspect simultaneous cardiac contusion or concussion. We analyzed the patients with possible cardiac injury by electrocardiography, serum creatine kinase (CK), creatine kinase isoenzyme fraction (CK-MB) screening, followed by two dimentional echocardiogram (2-DE) to access the severity of injury. Material and Method: From January 1997 to April 1998, 15-month retrospective study of suspicious myocardial injury was undertaken in including 24 patients admitted for suspected cardiac injury. All patients with history or signs of blunt chest injury were checked serially and the serial CK, CK-MB fraction, electrocardiography (EKG) analysis screening were followed by 2-DE. Result: The age range was between 20-40 years and were predominant male patients in(M:F=3:1). Most common causes of injury were traffic accidents, 15 patients(62.5%). Associated injuries involved multiple rib fractures, sternal fracture and such. EKG findings on the cardiac concussion were within normal limits, EKG findings on the cardiac contusion were nonspecific ST and T wave abnormality. In cardiac contusion patients, CK-MB fraction did not increase significantly on admission but on 2nd, 3rd, 4th hospital days, it increased significantly (p=0.0080, 0.0130, 0.0130). The average admission days were 9.22 in concussion and 26.18 in contusion patients(p=0.0075). Most common complication was the adult respiratory distress syndrome(7 cases), 5 out of the patients with ARDS were mechanically ventilated. There were no deaths. Conclusion: We believe the serial checks of CK-MB, EKG and subsquent two-dementional echocardiographic sector scanning are presently the most sensitive indicators available for structural and functional cardiac injury.

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The effects of Cudrania tricuspidata extract on bone metabolism in ovariectomized rats

  • Jo, You-Young;Seo, Sang Deog;Kim, Ji-Won;Cho, Hyun-Ji;Chon, Jeong-Woo;Lee, Kwang Gill;Lee, Heui-Sam;Park, Yoo-Kyoung;Kweon, HaeYong
    • International Journal of Industrial Entomology and Biomaterials
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    • v.32 no.2
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    • pp.80-89
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    • 2016
  • The effects of Cudrania tricuspidata (CT) extract on markers of osteoporosis were examined in ovariectomized rats. We classified 26 rats into five groups and provided a pellet chow diet and tap water throughout the 27-wk experimental period. During the last 15 wk, we added oral injections to each group as follows: sham-operated (SHAM, n=4) and ovariectomized-control (OVX, n=5) with distilled water, alendronate with 10 mg/kg/d of alendronate sodium (ALEN, n=5), CT (CT100, n=6) with 100 mg/kg/d of CT, and CT (CT300, n=6) with 300 mg/kg/d of CT. After the experimental period, blood, urine, and micro-CT images were assessed. The CT100 and OVX groups did not show any significant differences in urinary n-terminal telopeptide (NTx) (p<0.05 ), but with increases in CT concentration, the NTx level was slightly reduced. Serum osteocalcin was significantly higher in the CT groups than in all other groups (p<0.05 ). Notably, the serum calcium levels of all groups were within the normal range, but urinary calcium levels in the CT groups were significantly lower than the OVX group (p<0.05 ). In addition, the CT groups exhibited higher trabecular BMD than the OVX groups while showing similar BMD to the ALEN group (p<0.05 ). The Tb.Th of the ALEN group was lower than all other groups. Based on the overall analysis of results, CT prevented bone loss by inhibiting bone resorption and enhancing bone formation. Although alendronate showed a similar effect in preventing bone loss, it did so by solely inhibiting bone resorption, and its long-term use reportedly causes paradoxical effects such as hip fractures. Thus, for osteoporosis induced by ovariectomy, we conclude that CT extract is an effective natural treatment without severe side effects.

Late-term effects of hypofractionated chest wall and regional nodal radiotherapy with two-dimensional technique in patients with breast cancer

  • Yadav, Budhi Singh;Bansal, Anshuma;Kuttikat, Philip George;Das, Deepak;Gupta, Ankita;Dahiya, Divya
    • Radiation Oncology Journal
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    • v.38 no.2
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    • pp.109-118
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    • 2020
  • Purpose: Hypofractionated radiotherapy (RT) is becoming a new standard in postoperative treatment of patients with early stage breast cancer after breast conservation surgery. However, data on hypofractionation in patients with advanced stage disease who undergo mastectomy followed by local and regional nodal irradiation (RNI) is lacking. In this retrospective study, we report late-term effects of 3 weeks post-mastectomy hypofractionated local and RNI with two-dimensional (2D) technique in patients with stage II and III breast cancer. Methods: Between January 1990 and December 2007, 1,770 women with breast cancer who were given radical treatment with mastectomy, systemic therapy and RT at least 10 years ago were included. RT dose was 35 Gy/15 fractions/3 weeks to chest wall by two tangential fields and 40 Gy in same fractions to supraclavicular fossa (SCF) and internal mammary nodes (IMNs). SCF and IMNs dose was prescribed at dmax and 3 cm depth, respectively. Chemotherapy and hormonal therapy was given in 64% and 74% patients, respectively. Late-term toxicities were assessed with the Radiation Therapy Oncology Group (RTOG) scores and LENT-SOMA scales (the Late Effects Normal Tissue Task Force-Subjective, Objective, Management, Analytic scales). Results: Mean age was 48 years (range, 19 to 75 years). Median follow-up was 12 years (range, 10 to 27 years). Moderate/marked arm/shoulder pain was reported by 254 (14.3%) patients. Moderate/marked shoulder stiffness was reported by 219 (12.3%) patients. Moderate/marked arm edema was seen in 131 (7.4%) patients. Brachial plexopathy was not seen in any patient. Rib fractures were noted in 6 (0.3%) patients. Late cardiac and lung toxicity was seen in 29 (1.6%) and 23 (1.3%) patients, respectively. Second malignancy developed in 105 (5.9%) patients. Conclusion: RNI with 40 Gy/15 fractions/3 weeks hypofractionation with 2D technique seems safe and comparable to historical data of conventional fractionation (ClinicalTrial.gov Registration No. NCT04175821).

Hemipelvectomy in a Cat with Obstipation (심한 변비를 보이는 고양이에서 반골반절제술을 이용한 외과적 치료 증례)

  • Yoon, Hun-Young;Kim, Kyung-Hee;Jeong, Soon-Wuk
    • Journal of Veterinary Clinics
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    • v.30 no.2
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    • pp.119-122
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    • 2013
  • A 9-month-old female Korean short hair cat weighing 2.2 kg presented for evaluation of a two-week history of obstipation. The owner reported that the cat sustained pelvic fractures 4 months previous to the onset of fecal tenesmus. On physical examination, fecal tenesmus was observed and restriction of the movement of the right coxofemoral joint was evident. Rectal palpation revealed narrowing of the pelvic canal with a hard bony protuberance at the bilateral acetabulum and pubic bones. Radiographs revealed a distended colon with feces and narrowing of the pelvic canal with abnormal structure of the pelvic bone. Conservative management consisting of stool softeners and a warm water enema was instituted; however, there was no improvement in obstipation. Partial iliac, ischial, pubic, and acetabular ostectomies were performed. Postoperative radiographs and rectal palpation revealed the enlarged pelvic canal. Stool softeners (5 ml orally twice daily) was administered following surgery for 14 days and then tapered down to 2.5 ml for 14 days. A warm water enema was performed twice postoperatively. At examination 14 days postoperatively, no problems with defecation and gait were reported. There was no evidence of obstipation and lameness of the left pelvic limb 5 months postoperatively.

The Initiation of Slip on Frictional Fractures (마찰 전단면의 전단거동과 에너지방출률)

  • Park, Chi-Hyun
    • Tunnel and Underground Space
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    • v.20 no.5
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    • pp.344-351
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    • 2010
  • Slip along a frictional fracture can be approached as initiation and propagation of a mode II crack along its own plane. Fracture mechanics theories predict that under pure mode II loading initiation will occur when the energy release rate of the fracture attains a critical value ($G_{IIC}$), which is generally taken as a material property. For the past few years the rock mechanics group at Purdue University has investigated experimentally the dependence of $G_{IIC}$ on normal stress and on the frictional characteristics of a fracture. A number of experiments has been conducted first on acrylic, a material that, using photoelastic methods, allows visualization of the stress field ahead of the fracture tip; and later on gypsum, a rock model material with relatively low unconfined compression strength. The experimental investigation has been expanded to include other frictional materials with higher unconfined compression strength. Direct shear tests have been conducted on specimens made with cement paste. New observations together with previous experiments indicate that $G_{IIC}$ can only be considered a material property when the peak friction angle of the discontinuity is similar to the residual friction angle; otherwise the critical energy release rate increases with normal stress.