• Journal of the Korean Arthroscopy Society
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• v.16 no.2
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• pp.114-120
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• 2012

Purpose: The purpose of the study was to evaluate the usefulness and the stability of the superficial medial collateral ligament (MCL) release in posterior medial meniscus root repair. Materials and Methods: We compared 20 patients who underwent posterior medial meniscus root repair with superficial MCL preserved (PM) and 32 patients who underwent posterior medial meniscus root repair combined with superficial MCL release (RM) from April 2006 to September 2010. We excluded the patients combined with other surgery. To evaluate the postoperative valgus instability in RM group, we examined direct tenderness on MCL insertion, the subjective feeling of instability and valgus stress test at 3 months and 1 year follow-up. We compared the tourniquet time between PM group and RM group, and the clinical results were assessed by Lysholm score and International Knee Documentation Committee (IKDC) for the usefulness. Results: All patients had no clinically significant complication related to the superficial MCL release. Three months and 1 year follow-up, there were no positive tenderness test, no subjective symptoms and no significant increase of valgus instability although 5 patients examined grade I valgus instability. The mean tourniquet time was $41.3{\pm}12.7$ minutes in RM group and $53.5{\pm}13.6$ minutes in PM group. There was a significant difference in the tourniquet time between the two groups (P<0.05). Average Lysholm score was $56.8{\pm}5.5$ (range, 44-70) preoperatively and $85.1{\pm}5.8$ (range, 77-94) postoperatively in PM group, and was $56.2{\pm}5.4$ (range, 45-67) preoperatively and $87.4{\pm}3.9$ (range, 82-95) postoperatively in RM group (P<0.001). No significant difference of Lysholm score was found in both groups (P<0.05). Average IKDC scores was $42.6{\pm}3.9$ (range, 30-53) preoperatively and $77.2{\pm}6.3$ (range, 68-92) postoperatively in PM group, and was $42.7{\pm}5.7$ (range, 30-53) preoperatively and $89.6{\pm}2.9$ (range, 84-95) postoperatively in RM group (P<0.05). There was also no significant difference of IKDC score in both groups (P<0.05). Conclusion: The superficial MCL release in posterior medial meniscus root repair is useful to gain a wide surgical field and reduces the tourniquet time and does not lead to postoperative valgus instability. It can be considered clinically useful and safe procedure in medial meniscus posterior root repair.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.53-60
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• 2008

The cross-sections of continuous multi-span beams sometimes suddenly increase, or become stepped, at the interior supports of continuous beams to resist high negative moments. The three-dimensional finite-element program ABAQUS (2007) was used to analytically investigate the inelastic lateral-torsional buckling behavior of stepped beams subjected to linear moment gradient and resulted in the development of design equations. The ratios of the flange thickness, flange width, and stepped length of beam are considered for the analytical parameters. Two groups of 27 cases and 36 cases, respectively, were analyzed for doubly and singly stepped beams in the inelastic buckling range. The combined effects of residual stresses and geometrical imperfection on inelastic lateral-torsional buckling of beams are considered. First, the distributions of residual stress of the cross-section is same as shown in Pi and Trahair (1995), and the initial geometric imperfection of the beam is set by central displacement equal to 0.1% of the unbraced length of beam. The new proposed equations definitely improve current design methods for the inelastic lateral-torsional buckling problem and increase efficiency in building and bridge design.

• Journal of Chest Surgery
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• v.13 no.3
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• pp.174-185
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• 1980

It was my great nohour that I can be exposed to such plenty materials of the coronary bypass surgery. Here, I am summarizing the xoronary bypass surgery, clinically. The material is serial 101 patients who underwent coronary bypass surgery between July 17, 1979 to November 30, 1979 in Shadyside Hospital, University of Pittsburgh. 1. Incidence of the Atherosclerosis is frequent in white, male, fiftieth who are living in industrialized country. It has been told the etiologic factor of the atherosclerosis is hereditary, hyperlipidemia, hypertension, smoking, drinking, diabetes, obesity, stress, etc. 2. The main and most frequent complication of the coronary atherosclerosis is angina pectoris. Angina pectoris is the chief cause of coronary bypass surgery and the other causes of coronary bypass surgery are obstruction of the left main coronary artery, unstable angina, papillary muscle disruption or malfunction and ventricular aneurysm complicated by coronary artery disease. 3. The preoperative clinical laboratory examination shows abnormal elevation of plasma lipid in 82 patint, plasma glucose in 40 patient, total CPK-MB in 24 patient stotal LDH in 22 patient out of 101 patient. 4. Abnormal ECG findings in preoperative examine were 29.1% myocardial infarction, 25.8% ischemia and injury, 14.6T conduction defect. 5. Also we had done Echocardiography, Tread Mill Test, Myocardial Scanning, Vectorcardiography and Lung function test to get adjunctive benefit in prediction of prognosis and accurate diagnosis. 6. The frequency of coronary atherosclerosis in main coronary arteries were LAD, RCA and Circumflex in that order. 7. The patients' main complaints which were became as etiologic factor undergoing coronary bypass surgery were angina, dyspnea, diaphoresis, dizziness, nausea and etc. 8. For the coronary bypass surgery, we used cardiopulmonary bypass machine, non-blood, diluting prime, cold cardioplegic solution and moderate cooling for the myocardial protection. 9. We got the grafted veins from Saphenous and Cephalic vein. Reversed and anastomosed between aorta and distal coronary A. using 5-0 and 7-0 prolene continuous suture. Occasionally we used internal mammary A. as an arterial blood source and anastomosed to the distal coronary A. and to side fashion. 10. The average cardiopulmonary bypass time for every graft was 43.9 min. and aortic clamp time was 23 minute. We could Rt. coronary A. bypass surgery only by stand by the cardiopulmonary machine and in the state of pumping heart. 11. Rates by the noumbers of graft were as follow : 21.8% single, 33.7% double, 26.7% triple, 13.9% quadruple, 3% quintuple and 1% was sixtuple graft. 12. combined procedures with coronary bypass surgery were 6% aneurysmectomy, 3% AVR, 1% MVR, 13% pacer implantation and 1% intraaortic ballon setting. 13. We could see the complete abolition of anginal pain after operation in 68% of patient, improvement 25.8%, no change in 3.1%, and there was unknown in 3%. 14. There were 4% immediate postoperative deaths, 13.5% some kinds of heart complication, 51.3% lung complications 33.3% pleural complications as prognosis.

• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.327-335
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• 2009

In the seismic region, non-ductile structures often form soft story and exhibit brittle collapse. However, structure demolition and new structure construction strategies have serious problems, as construction waste, environmental pollution and popular complain. And these methods can be uneconomical. Therefore, to satisfy seismic performance, so many seismic retrofit methods have been investigated. There are some retrofit methods as infill walls, steel brace, continuous walls, buttress, wing walls, jacketing of column or beam. Among them, the infilled frames exhibit complex behavior as follows: flexible frames experiment large deflection and rotations at the joints, and infilled shear walls fail mainly in shear at relatively small displacements. Therefore, the combined action of the composite system differs significantly from that of the frame or wall alone. Purpose of research is evaluation on the seismic performance of infill walls, and improvement concept of this paper is use of SHCCs (strain-hardening cementitious composites) to absorb damage energy effectively. The experimental investigation consisted of cyclic loading tests on 1/3-scale models of infill walls. The experimental results, as expected, show that the multiple crack pattern, strength, and energy dissipation capacity are superior for SHCC infill wall due to bridging of fibers and stress redistribution in cement matrix.

• Tunnel and Underground Space
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• v.13 no.5
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• pp.362-372
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• 2003

Since the occurrence of Portland cement, a great number of concrete structures were constructed. But the concrete structures have their own life times, which inevitably demand repairing treatments, especially on their surface parts. Currently many various methods have been developed and are being applied fer this purpose. In this study, a newly developed method using pneumatic chipping machine and anchor pin was adopted far repair of old concrete structure and the mechanical characteristics of cementing plane between existing and new concrete were tested. Comparing the removal methods for the decrepit part of existing concrete using pneumatic chipping machine and hydraulic breaker, the peak cohesion was higher when using chipping machine at the cementing plane. On the other hand, the residual cohesion was higher for the case of breaker. Step shaped chipping on the cementing plane was effective in increasing peak cohesion, which results 14% increase in the case of 30 mm step height and 22% in 50 mm height when compared with planar chipping plane. The use of anchor pin increased the residual cohesion, which restricted shear slip on the cementing plane after peak shear stress and the tensile strength of 32% compared with that of non-anchored case. According to the combined effect of step shaped chipping of 30 mm and anchor pin with an interval of 15 cm, the peak cohesion reached up to 77% and the residual cohesion showed 180% of the ones of the fresh concrete, respectively.

• Journal of the Korean Geographical Society
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• v.47 no.3
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• pp.328-346
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• 2012

This study provides quantitative constraints on Neogene uplift in the Korean peninsula using onshore paleo-shoreline records and seismic data. The eastern margin of Northeast Asia including Korea sits in the back-arc system behind the Western Pacific Subduction Zone, a complex trench triple junction of the Philippine Sea, Pacific, and Eurasian (Amurian) plates. An analysis of seismic data in the subduction zone shows that the pattern of uplift in the peninsula mirrors the extent of deep seismicity in subducting Pacific plate beneath. Combined with previous tomographic studies it is proposed that uplift is partly driven by asthenospheric upwelling caused by a sinking slab during the Neogene. In addition, the SHmax orientations of E-W and N-S trends in the peninsula are consistent with the prevailing in-situ stress fields in the eastern Eurasian continent generated by various plate boundary forces. The uplift in Korea during the Late Neogene is attributed, in part, to lithospheric failure relating to faulting movements, thus providing a link between dynamic effects of mantle upwelling at sinking slab edge and lithospheric responses driven by plate boundary forces.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.820-828
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• 2015

This study was carried out to determine the effects of vernalization, temperature, and soil water deficit (SD) on mesophyll cells, growth, and yield of Chinese cabbage (Brassica campestris L). The palisade parenchyma and spongy tissues of Chinese cabbage were observed under full irrigation and two weeks of SD treatment. These cells were severely collapsed by four weeks SD treatment. The SD treatment had the greatest influence on the growth of Chinese cabbage among the tested treatment factors (vernalization, temperature, and SD), growth significantly decreased by severe drought treatment (four weeks SD treatment). In addition, the relative growth rate, unit leaf rate, leaf area ratio, specific leaf area, and leaf weight ratio were significantly affected by SD treatment; however, other individual factors and their combined treatments did not influence the analyzed growth parameters. The yield under vernalization after high temperature and full irrigation treatments was 3,056 kg/10 a, which was the greatest among all the tested treatments, while four-week SD treatment significantly reduced the yield. Head formation of Chinese cabbage was not altered under SD treatment, and vernalization treatments did not induce bolting. Our results indicated that collapsing mesophyll cells and reduced growth and yield were induced by SD treatment. Thus we suggest that optimal irrigation system should be install to avoid or overcome crippling drought conditions in the open field.

• Journal of the Korean Wood Science and Technology
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• v.44 no.1
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• pp.30-39
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• 2016

The evaluation of the lateral load performance for larch glulam portal frames was carried out using glass fiber reinforced plastic (GFRP) as connector in two different systems: the GFRP-reinforced laminated plates combined with veneer, and GFRP rod joints glued with epoxy resins to replace usual metal connectors for the structural glulam rahmen joints. As a result the yield strength, ultimate strength, initial stiffness of glulams of GFRP rod joints glued with epoxy resin decreased to 49%, 52% and 61% compared to those of the conventional metal connector. This connector will be a stress device where the bonding strength between the GFRP rod and glued laminated timber is important. Thus, there will be a high possibility that a problem may occur when it is applied to the field. On the other hand, the GFRP-reinforced laminated plates and wood (Eucalyptus marginata) pin were measured all within 3% for all measurements of the yield strength, ultimate strength, initial strength and ductility factor, regardless of high cross sectional loss on the glued laminated timber slit joint. In addition, the variation of stiffness on the cycle was 35%, which was the lowest, confirming that it was almost the same performance as the specimen prepared with the metal connector.

• Journal of the Korea Concrete Institute
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• v.18 no.1 s.91
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• pp.13-19
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• 2006

This paper reports the test results for shrinkage properties of low shrinkage high performance concrete developed by the authors depending on specimen size and constraint of reinforcing bar. As properties in fresh concrete low shrinkage high performance concrete(LSHPC) combined with expansive additives and shrinkage reducing admixture resulted in increase SP dosage due to loss of fluidity compared with that of control mixture concrete, while the dosage of AE agent was decreased. LSHPC exhibited higher compressive and tensile strength than control mixture concrete. For the effect of specimen size, an increase in specimen size led to a reduction of drying shrinkage. However, it was found that the autogenous shrinkage was not affected by the specimen size and measuring method. For constraint condition, an increase in the ratio of reinforcing bar caused the slight reduction in the strain of reinforcing bar, while it increased the autogenous shrinkage stress. It was seen that LSHPC was effective to reduce autogenous shrinkage by as much as 70% compared with control mixture high performance concrete.

• Environmental Mutagens and Carcinogens
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• v.22 no.3
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• pp.142-148
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• 2002

Although ionizing radiation (IR) has been used to treat the various human cancers, IR is cytotoxic not only to cancer cells but to the adjacent normal tissue. Since normal tissue complications are the limiting factor of cancer radiotherapy, one of the major concerns of IR therapy is to maximize the cancer cell killing and to minimize the toxic side effects on the adjacent normal tissue. As an attempt to develop a method to monitor the degree of radiation exposure to normal tissues during radiotherapy, we investigated the transcriptional responses of human peripheral blood lymphocytes (PBL) following IR using cDNA microarray chip containing 1,221 (1.2 K) known genes. Since conventional radiotherapy is delivered at about 24 h intervals at 180 to 300 cGy/day, we analyzed the transcriptional responses ex-vivo irradiated human PBL at 200 cGy for 24 h-period. We observed and report on 1) a group of genes transiently induced early after IR at 2 h, 2) of genes induced after IR at 6 h, 3) of genes induced after IR at 24 h and on 4) a group of genes whose expression patters were not changed after IR. Since Biological consequences of IR involve generation of various reactive oxygen species (ROS) and thus oxidative stress induced by the ROS is known to damage normal tissues during radiotherapy, we further tested the temporal expression profiles of genes involved in ROS modulation by RT-PCR. Specific changes of 6 antioxidant genes were identified in irradiated PBL among 9 genes tested. Our results suggest the potential of monitoring post-radiotherapy changes in temporal expression profiles of a specific set of genes as a measure of radiation effects on normal tissues. This type of approach should yield more useful information when validated in in vivo irradiated PBL from the cancer patients.