• 문화기술의 융합
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• 제6권3호
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• pp.443-448
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• 2020

본 연구에서는 영종대교를 구성하고 있는 교량형식(트러스교, 현수교)별 열차종류(AREX, AREX Express, KTX, KTX-Sancheon) 및 열차속도가 강직결 궤도구조의 동적거동에 미치는 영향을 분석하고자 현장측정을 수행하였다. 현장측정결과를 바탕으로 궤도충격계수 및 열차주행안정성(탈선계수, 윤중감소율, 레일두부횡변위)을 국내, 외 관련기준 및 법규와의 비교하여 영종대교 교량상 강직결 궤도구조의 동적거동에 영향을 미치는 열차하중 및 속도의 효과를 분석하였다. 연구결과, 영종대교 교량형식별 궤도의 동적거동의 차이는 뚜렷하지 않으나 열차하중의 크기에 보다 직접적인 영향을 받는 것으로 분석되었다. 따라서 향후 열차속도 증가에 따른 궤도충격계수의 증가와 이에 따른 궤도부담력의 증가수준을 감안한 영종대교 강직결 궤도구조의 보강방안 수립이 필요할 것으로 판단된다.

• Clinics in Shoulder and Elbow
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• 제8권1호
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• pp.19-22
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• 2005

Purpose: The causes of twelve cases of the mid-shaft clavicle nonunion and the results of internal fixation with plate and bone graft were investigated. Materials and method: From August 1997 to March 2003, twelve cases of the mid-shaft clavicle nonunion were operated with internal fixation with plate and bone graft. The duration of follow-up was average 13 months. Results: The causes of the mid-shaft clavicle nonunion included severe associated injury, severe initial displacement of the fracture fragments and insecure fixation. All cases were operated with internal fixation with plate and bone graft. According to the factor for evaluations of results, using a rating scale of excellent (no apparent factors), good (one factor), fair (two factors), poor (more than three factors), the results showed 10 excellent, 1 good and 1 poor. Screw loosening was developed in only one case . Conclusion: The internal fixation with plate and bone graft of the mid-shaft clavicle nonunion after failed conservative treatment achieved excellent results and seemed to be the procedure of choice for mid-shaft clavicle nonunion.

• 대한관절경학회지
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• 제2권1호
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• pp.85-92
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• 1998

Various methods for fixation of graft have been widely used for reconstruction of anterior cruciate ligament. However, the biomechanical strength of each fixation techniques are not fully understood. The purpose of this study is to compare the pull out strength of different fixation techniques which is probably the most important factor for the success at the initial stage of healing. Biomechanical test was carried out to measure and compare the pull out tensile strength of five different fixation techniques in 35 pig(Yorkshire) knees. ANOVA and Duncan multiple comparison test was applied for statistical analysis. In the two fixation techniques with bone patellar tendon bone graft, the mean maximum tensile strength was $1333.4{\pm}148.5N$ with titanium interference screw, while it was $1310.1{\pm}168.9N$ with biodegradable interference screw. The failure mode were pulled out of bone plugs from the femoral tunnel in majority cases. In the fixations with hamstring tendon, the mean maximum tensile strength were $1405.9{\pm}135.1N$ with SemiFix screw, $820.3{\pm}104.5N$ with biodegradable interference screw, and $682.1{\pm}54.2N$ with Endobutton. The mode of failure was variable in each technique. The tendon was pulled out from the tunnel in biodegradable interference screw fixation, the screw was bent in the SemiFix system, and the polyester tape were ruptured or the buttons were pulled into tunnel in Endobutton fixation. The mean maximum tensile strength of two interference screws with bone patellar tendon bone was statistically comparable to that of SemiFix with hamstring tendon. However biodegradable interference screw and Endobutton with hamstring tendon showed weaker maximum tensile strength than above three fixation techniques (P<0.05).

• 대한수의학회지
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• 제12권1호
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• pp.97-119
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• 1972

Studies on modified complement fixation (MCF) test of antiblackleg bovine serum were made and the results obtained were summarized as followings. 1. The most satisfactory antigen for the MCF test among various materials studied was found to be the vegetative cells of Cl, chauvoei grown in cooked meat medium (CMM) containing 0.5mM l-(alpha) alanine and 0.1mM manganese. The antigen was prepared by inoculating the spores of Cl. chauvoei, heated at $70^{\circ}C$. for 30 minutes, into the CMM followed by incubation at $37^{\circ}C$. for 15 hours. 2. An active component contained in the factor serum of fresh normal rabbit serum was found to be C'4 fraction. It was also shown that, furthermore, DEAE cellulose sieved C'4 fraction of the factor serum enhanced antibody titer and the highest antibody titer was resulted by the addition of 0.03 ml, of the factor serum to each tube. 3. More than four fold increases of antibody titer, in antiblbckleg bovine serum-antigen system, was made with the MCF test than that with the direct complement fixation test. 4. The MCF antibody titer of cattle vaccinated against blackleg was 128 until seven month and 64 for five months thereafter.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권3호
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• pp.175-181
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• 2002

Intermaxillary fixation and occusal splint are routine procedure for maxillofacial fracture and orthognathic surgery. When these methods could obstruct oral airway the patients who kept intermaxillary fixation and occusal splint in their mouth, are very difficult to breath after surgery. Nasal bleeding and pharyngeal edema due to nasotracheal intubation, residual effect of muscle relaxants, and anesthetic agent could be contributing factor of airway obstruction. In this study, pulmonary function test was evaluated before and after intermaxillary fixation, and intermaxillary fixation with occusal splint in 22 volunteers. The results were as follows 1. FVC, %FVC, $FEV_1$, $FEV_1%$, PEF, $PEF_{50}$, MVV without intermaxillary fixtion were 4.45L, 88%, 4.03L, 90.9%, 10.26L/s, 5.53L/s, and 136.14L/min, and with intermaxillary fixation were 3.51L, 68.67%, 3.06L, 69.39L, 6.52L/s, 3.94L/s, and 69.39L/min. The results with intermaxillary fixation and occusal splint were 2.15L, 42.41%, 1.71L, 38.81%, 2.83L/s, 1.74L/s, and 37.14L/min. 2. Compared with before and after intermaxillary fixation, all values of pulmonary function test were decreased and after intermaxillary fixation and intermaixillary fixation with occulasal splint, the results were decreased. 3. MVV and PEF were decreased significantly with interaxillary fixtion and occusal splint, and FVC was less decreased. It meant that intermaxillary fixation and occluasal splint induced reduction of respiratory flow significantly, but less reduction of respiratory volume. 4. Intermaxillary fixation and occulsal splint induced increase of airway resistance, decrease of expiratory volume and air flow. So severe respiratory difficulty could be seen to all volunteers who kept intermaxillary fixtion and occusal splint. 5. In classification of respiratory difficulty, intermaxillary fixation with occulsal splint induced complex respiratory difficulty more than intermaxillary fixation only did. From the above results, doctors who care patients kept intermaxillary fixation and occusal splint should be aware of respiratory depression caused by these treatment.

• Journal of Trauma and Injury
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• 제32권4호
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• pp.220-225
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• 2019

Purpose: Mechanical ventilation (MV) is an essential life-saving modality for severely injured patients. However, the long-term use of MV is a major risk factor for late mortality. The surgical correction of long bone fractures plays a critical role not only in improving functional outcomes, but also in reducing physiological derangements, including MV duration. This study investigated the factors affecting prolonged MV (PMV) in severely injured patients with femur fractures. Methods: We retrospectively evaluated all severely injured patients (injury severity score >15) with femur fractures who were taken to the emergency department within 12 hours of the causative accidents between January 2016 and December 2018. PMV was defined as MV lasting for ≥7 days. We analyzed the factors affecting PMV. Results: In total, 35 patients were enrolled and 21 (33.3%) were included in the PMV group. The PMV group required more red blood cell (RBC) transfusions within 7 days RBC (7dRBC) (12.8 vs. 6.8 units; p=0.03) and the time to femur fracture fixation (TFFF) was longer (7.9 vs. 2.7 days; p=0.018). The area under the curve (AUC) for TFFF was 0.740 (95% confidence interval [CI]: 0.572-0.908; p=0.018) and the AUC for 7dRBC was 0.718 (95% CI: 0.546-0.889; p=0.031). Conclusions: This study indicates that TFFF is an independent risk factor for PMV. Early fixation of femur fractures might prevent PMV and its associated complications.

• The Journal of Korean Physical Therapy
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• 제13권3호
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• pp.665-675
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• 2001

The aim of this study was to compare features of muscle atrophy induced by cast fixation. denervation and suspension of rat hindimb. Muscle mass and glycogen of the soleus and plantaris muscles were studied after 3, 7, or 14 days of cast fixation, denervation and suspension. The results as follows: 1. Body weight of rats decreased significantly after 3 days and showed gradually increase after 7 and 14 days of hindlimb cast fixation, denervation and suspension. Particularly hindlimb suspended rats showed a rapid decrease after 3 days in body weight. 2. Relative weight of soleus and plantaris musclcs decreased significantly by hindlimb cast fixation, denervation and suspension, particularly after 7 days. The decrease rate was the lowest in suspended rats. 3. Glycogen content of soleus muscle decreased significantly after 14 days of hindlimb cast fixation, denervation and suspension. Also glycogen content of plantaris muscle decreased significantly after 14 days of hindlimb cast fixation and denervation, but not significantly after hindlimb suspension. These results indicate that suspension of hindlimb muscles causes less atropy than cast fixation or denervation, likely due to maintainment a few activities during hindlimb suspension. We concluded that the decrease in mechanical strains imposed on the muscle during inactivity was the main factor for the development of atrophy. These basic data suggest that some experimental conditions such as electrostimulation or stretching, participate in countermeasure programmes.

• Molecules and Cells
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• 제40권1호
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• pp.24-36
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• 2017

The stability of peptide-MHC complex (pMHC) is an important factor to shape the fate of peptide-specific T cell immune response, but how it influences on T cell activation process is poorly understood. To better understand that, we investigated various T cell activation events driven by $L^d$ MHCI loaded with graded concentrations of P2Ca and QL9 peptides, respectively, with 2C TCR Tg T cells; the binding strength of P2Ca for $L^d$ is measurably weaker than that of QL9, but either peptides in the context of $L^d$ interact with 2C TCR with a similar strength. When their concentrations required for early T cell activation events, which occur within several minutes to an hour, were concerned, $EC_{50}s$ of QL9 were about 100 folds lower than those of P2Ca, which was expected from their association constants for $L^d$. When $EC_{50}s$ for late activation events, which takes over several hours to occur, were concerned, the differences grew even larger (> 300 folds), suggesting that, due to weak binding, $L^d/P2Ca$ dissociate from each other more easily to lose its antigenicity in a short time. Accordingly, fixation of $L^d/P2Ca$ with paraformaldehyde resulted in a significant improvement in its immunogenicity. These results imply that binding strength of a peptide for a MHC is a critical factor to determine the duration of pMHC-mediated T cell activation and thus the attainment of productive T cell activation. It is also suggested that paraformaldehyde fixation should be an effective tool to ameliorate the immunogenicity of pMHC with a poor stability.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.50-57
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• 2010

Various installation faults may lie in fasteners in the construction of a direct-fixation track by the top-down method. At an extreme, they may cause excessive interaction between the train and track, compromise the running safety of the train, and cause damage to the track components. Therefore, the faults need to be kept within the allowable level through an investigation of their effects on the interactions between the train and track. In this study, the vertical dynamic stiffness of fasteners in installation faults was measured based on the dynamic stiffness test by means of an experimental apparatus that was devised to feasibly reproduce gap faults. This study proposes an effective analytical model for a train-track interaction system in which most elements, except the nonlinear wheel-rail contact and some components that behave bi-linearly, exhibit linear behavior. To investigate the effect of the behavior of fasteners in gap faults in a direct-fixation track on the vehicle and track, vehicle-track interaction analyses were carried out, targeting key review parameters such as the wheel load reduction factor, vertical rail displacement, rail bending stress, and mean stress of the elastomer. From the results, it was noted that the gap faults in the concrete bearing surface of a direct-fixation track need to be limited for the sake of the long-term durability of the elastomer than for the running safety of the train or the structural safety of the track.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2008년도 International Meeting of the Microbiological Society of Korea
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• pp.23-25
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• 2008

Serum complement proteins comprise an important system that is responsible for several innate and adaptive immune defence mechanisms. There were three well described pathways known to lead to the generation of a C3 convertase, which catalyses the proteolysis of complement component C3, and leads to the formation of C3 opsonins (C3b, iC3b and C3d) that fix to bacteria. A pivotal step in the complement pathway is the assembly of a C3 convertase, which digests the C3 complement component to form microbial-binding C3 fragments recognized by leukocytes. The spleen clears microorganisms from the blood. Individuals lacking this organ are more susceptible to Streptococcus pneumoniae. Innate resistance to S. pneumoniae has previously been shown to involve complement components C3 and C4, however this resistance has only a partial requirement for mediators of these three pathways, such as immunoglobulin, factor B and mannose-binding lectin. Therefore it was likely that spleen and complement system provide resistance against blood-borne S. pneumoniae infection through unknown mechanism. To better understand the mechanisms involved, we studied Specific intracellular adhesion molecule-grabbing nonintegrin (SIGN)-R1. SIGN-R1, is a C-type lectin that is expressed at high levels by spleen marginal-zone macrophages and lymph-node macrophages. SIGN-R1 has previously been shown to be the main receptor for bacterial dextrans, as well as for the capsular pneumococcal polysaccharide (CPS) of S. pneumoniae. We examined the specific role of this receptor in the activation of complement. Using a monoclonal antibody that selectively downregulates SIGN-R1 expression in vivo, we show that in response to S. pneumoniae or CPS, SIGN-R1 mediates the immediate proteolysis of C3 and fixation of C3 opsonins to S. pneumoniae or to marginal-zone macrophages that had taken up CPS. These data indicate that SIGN-R1 is largely responsible for the rapid C3 convertase formation induced by S. pneumoniae in the spleen of mice. Also, we found that SIGN-R1 directly binds C1q and that C3 fixation by SIGN-R1 requires C1q and C4 but not factor B or immunoglobulin. Traditionally C3 convertase can be formed by the classical C1q- and immunoglobulin-dependent pathway, the alternative factor-B-dependent pathway and the soluble mannose-binding lectin pathway. Furthermore Conditional SIGN-R1 knockout mice developed deficits in C3 catabolism when given S. pneumoniae or its capsular polysaccharide intravenously. There were marked reductions in proteolysis of serum C3, deposition of C3 on organisms within SIGN-$R1^+$ spleen macrophages, and formation of C3 ligands. The transmembrane lectin SIGN-R1 therefore contributes to innate resistance by an unusual C3 activation pathway. We propose that in the SIGN-R1 mediated complement activation pathway, after binding to polysaccharide, SIGN-R1 captures C1q. SIGN-R1 can then, in association with several other complement proteins including C4, lead to the formation of a C3 convertase and fixation of C3. Therefore, this new pathway for C3 fixation by SIGN-R1, which is unusual as it is a classical C1q-dependent pathway that does not require immuno globulin, contributes to innate immune resistance to certain encapsulated microorganisms.