Showing papers by "Yonsei University published in 1988"
TL;DR: In this paper, a general three-dimensional plastic potential function expressed in terms of stress invariants is proposed based on review and evaluation of a large number of test data, which includes tensile behavior of materials with effective cohesion.
182 citations
TL;DR: In this article, a yield function is proposed such that yield surfaces are equivalent to plastic work contours, and two parameters are required in this function: the yield surface resembles an asymmetric tear drop in the principal stress space.
170 citations
TL;DR: There was a low incidence of deep-vein thrombosis in patients in whom obesity, prolonged immobilization postoperatively, varicose veins, and hyperlipemia were not factors, and hypertension, blood group, surgical approach, and choice of cemented or cementless total hip replacement did not seem to affect the incidence.
Abstract: The incidence of deep-vein thrombosis was studied in 146 consecutive Korean patients who had a cementless total hip replacement with a porous-coated anatomic prosthesis. All of the patients had discontinued taking aspirin, aspirin-containing compounds, or other antiplatelet medications fourteen days before admission to the hospital for the operation. Deep-vein thrombosis was diagnosed by roentgenographic venography, and pulmonary embolism, by perfusion lung-scanning. There was an unusually low incidence (10 per cent) of deep-vein thrombosis in this series. In contrast to other reports, we did not identify a relationship between deep-vein thrombosis and so-called risk factors such as advanced age, number of venous valves (more than five) in the lower extremity, abnormal coagulation-assay data, certain diseases, or preoperative limitation of mobility. In addition, hypertension, blood group, surgical approach, and choice of cemented or cementless total hip replacement did not seem to affect the incidence of deep-vein thrombosis. There was a low incidence of deep-vein thrombosis in patients in whom obesity, prolonged immobilization postoperatively, varicose veins, and hyperlipemia were not factors.
109 citations
TL;DR: In this paper, a unified constitutive model for the behavior of frictional materials is described, which is based on concepts from elasticity and plasticity theories, including Hooke's law for the elastic behavior, a nonassociated flow rule, a yield criterion that describes contours of equal plastic work, and a workhardening/softening law.
105 citations
TL;DR: Findings suggest that idiopathic calcinosis of the scrotum derives from the dystrophic calcification of cysts.
Abstract: A 29-year-old man had a 2-year history of multiple, asymptomatic, firm, subcutaneous nodules on the scrotal skin, which sometimes discharged a chalky material. Fifty-one nodules were observed in the histopathologic examination, which revealed, in addition to the typical findings of idiopathic calcinosis of the scrotum, various forms of intact cysts: epidermal (some calcified), pilar (calcified), hybrid (calcified), and indeterminate cysts with diffusely calcified keratinous content and attenuated walls. A mixture of calcified keratinous material and inflammatory infiltrates was detected, with or without remnants of the cyst wall. These findings suggest that idiopathic calcinosis of the scrotum derives from the dystrophic calcification of cysts.
85 citations
TL;DR: In this paper, steady-state natural convection of a saltwater solution due to the combined horizontal temperature and concentration gradients is studied experimentally in rectangular enclosures of aspect ratio, 0.2 and 2.0.
77 citations
TL;DR: A three-dimensional finite-element model of the thorax and neck using eight-node trilinear hexahedron elements suggests that an approximately linear relationship exists between the impedance change and blood volume change in the aorta.
Abstract: A three-dimensional finite-element model of the thorax and neck using eight-node trilinear hexahedron elements was constructed to investigate the impedance change associated with various physiological events during systole. A three-dimensional finite-element code was developed to solve the generalized Laplace equation with Dirichlet and homogeneous Neumann boundary conditions. The current in each element as well as potential at each node was calculated. The results suggest that an approximately linear relationship exists between the impedance change and blood volume change in the aorta. This is a promising result since the relationship helps explain the correlation between impedance cardiography and invasive techniques. Impedance changes due to blood volume changes in the aorta and ventricles, the lung-resistivity change, and the blood-resistivity change were calculated for standard impedance electrode configurations. >
68 citations
TL;DR: The dissections revealed that the postauricular surface is mainly supplied by three to five sizable branches from the upper, middle, and lower divisions of the posterior auricular artery, traversing in a rather straight and cephalic direction toward the auricular rim.
Abstract: We studied the arterial pattern of the postauricular surface in 16 cadavers and compared them to the results of Doppler probing in the auricles of 15 human volunteers. The dissections revealed that the postauricular surface is mainly supplied by three to five sizable branches from the upper, middle, and lower divisions of the posterior auricular artery, traversing in a rather straight and cephalic direction toward the auricular rim. One or more branches of the middle division are constantly present and distribute over the upper two-thirds of the postauricular surface. These anatomic findings were compatible with the results of the Doppler probing. We have done four auricular reconstructions with postauricular arterial flaps with excellent postoperative results. It is worthwhile to use the postauricular arterial flap in restoring the middle third of the auricle.
60 citations
TL;DR: In this paper, the authors derived the stress intensity factors for bimaterial interface cracks by the boundary element method employing the multi-region technique and the double-point concept, which is applicable to both the homogeneous and the bimmaterial systems.
55 citations
TL;DR: In this article, the dielectric properties of lead magnesium niobate (PMN) have been investigated as a function of the amount of excess PbO and excess MgO in the range of 0-40 m/o and 0-150 m/O, respectively.
Abstract: The dielectric properties of lead magnesium niobate (PMN) have been investigated as a function of the amount of excess PbO and excess MgO in the range of 0–40 m/o and 0–150 m/o, respectively. In the case of PMN with both 40 m/o excess PbO and 5 m/o excess MgO added, the pyrochlore phase was completely eliminated. And there was great increase in grain size and dielectric constant as compared to PMN with no excess MgO. But in the range of 10–150 m/o excess MgO, the dielectric constant tended to decrease with increase in the amount of excess MgO even though no pyrochlore phase was found to be present. Also, the MgO rich second phase appeared to precipitate. These results can be explained by microstructure analysis.
55 citations
TL;DR: Nineteen patients (twenty-two knees) who had tuberculous arthritis of the knee who had a total knee arthroplasty had recurrence of the infection, which was controlled satisfactorily in one by chemotherapy alone and in the other by chemotherapy and débridement of a sinus tract, without removal of the prosthesis.
Abstract: Nineteen patients (twenty-two knees) who had tuberculous arthritis of the knee had a total knee arthroplasty. The interval between the subsidence of signs of infection and the arthroplasty ranged from three months to five years, and the period of follow-up ranged from twenty-four to forty-nine months. Culture of fluid that had been aspirated from the joint preoperatively and culture of a biopsy specimen were negative. Biopsies of specimens of synovial material revealed tuberculous granuloma in all patients, despite negative findings for acid-fast organisms. The prosthesis was implanted with cement in four knees and without cement in eighteen. The mean functional rating was 39 points preoperatively and 83 points at the time of final follow-up. No component loosened. One patient had an arthrodesis because of recurrent active tuberculous infection. Two other patients had recurrence of the infection, which was controlled satisfactorily in one by chemotherapy alone and in the other by chemotherapy and debridement of a sinus tract, without removal of the prosthesis.
TL;DR: Sacral defects from 6 to 11 cm in diameter were closed with bilateral fasciocutaneous V-Y advancement flaps and the technique has some major advantages for repair of moderate-size sacral defects.
Abstract: Sacral defects from 6 to 11 cm in diameter were closed with bilateral fasciocutaneous V-Y advancement flaps. All the defects were easily closed without any postoperative complication. We believe that the V-Y advancement technique using the fasciocutaneous unit has some major advantages for repair of moderate-size sacral defects. It is a safe, simple, and less invasive procedure.
TL;DR: It is possible that this carcinogen, as well as friction and the local irritation of long‐standing Hailey‐Hailey skin lesions, may be the predisposing factors for the development of SCC in this case.
Abstract: A case of squamous cell carcinoma (SCC) arising in a lesion of Hailey-Hailey disease at the penoscrotal junction is reported. The patient was treated with arsphenamine (Salvarsan 606) early in the disease. It is possible that this carcinogen, as well as friction and the local irritation of long-standing Hailey-Hailey skin lesions, may be the predisposing factors for the development of SCC in this case.
TL;DR: A Total of 498 cases of hemophilia which were reported by sixteen medical centers in Korea were reviewed and analyzed and found that the incidence of hemarthrosis increased significantly with age.
Abstract: A Total of 498 cases of hemophilia which were reported by sixteen medical centers in Korea were reviewed and analyzed Hemophilia A comprised 425 cases (853%) and the remaining 73 cases (147%) were hemophilia B One case was female and all other cases were male There were known hemophilia patients in the family in 430% of cases and the involved members were brothers, maternal cousins, maternal uncles, and maternal grandfathers in descending order of frequency The major symptoms of the patients were hemorrhagic, such as easy bruising and hemarthrosis followed by prolonged bleeding after trauma and soft tissue hematoma The incidence of hemarthrosis increased significantly with age The pediatric age group below the age of 15 consisted of 671% of the cases According to the age at diagnosis, half (542%) of the severe cases were diagnosed before the age of 1 year APTT was prolonged over 40 seconds in all cases and 291 cases showed severe prolongation over 80 seconds Of 498 cases 273 cases (548%) belonged to the severe form (factor VII or IX level, less then 1%), whereas 182 cases (365%) and 43 cases (87%) belonged to the moderate (factor VIII or IX, 2-5%) and mild form (factor VIII or IX, 6-25%), respectively, Chronic arthropathy was present in 236 cases (496%), and the incidence increased significantly with age The management of chronic arthropathy most commonly employed was rehabilitation in 254% of cases, but in 508% no management was given at all The involved joints in descending order of frequency were knees, elbows and ankles The complications were intracranial hemorrhage, Gl bleeding and nerve palsy in 48, 24, and 13 cases, respectively
TL;DR: New endemic areas of Metagonimus infection were discovered along the Hongcheon river basin and the main source of infection was the fresh water fish, Z. platypus.
Abstract: The Hongcheon river system flows down through the Hongcheon area of Kangwon-do, and reaches to the Cheongpyeong Dam in Kyonggi-do. Stool specimens from the inhabitants residing along the Hongcheon river basin were examined to detect infection rate of Metagonimus sp., and the intermediate hosts were collected to detect larval stages. The results obtained were as follows: Thirty-nine (33 males and 6 females) out of 529 (314 males and 215 females) inhabitants were infected with Metagonimus sp., showing a total positive rate of 7.4 per cent. In eight areas surveyed, the specimens from Kulji-ri of Bukbang-myon at the middle part of the river showed the highest positive rate of 26.9 per cent (14 positives out of 52) (males; 38.2 per cent). The specimens from Mogog-ri of Seo-myon at the downstream of the river showed a positive rate of 10.4 per cent (13 positives out of 125) (males;12.6 per cent). The positive rates in other regions were less than 10 per cent. The density of the first intermediate host, Semisulcospira sp., was the highest in Kulji-ri of Bukbang-myon (10-20 snails per m(2)), and the infection rate of Metagonimus cercariae in the snails was 10.7 per cent(13 positives out of 121 snails). The infection rate of Metagonimus metacercariae in Zacco platypus, the fresh water fish favorably eaten raw by the inhabitants, was 68.2 per cent (30 positives out of 44 fishes), and most metacercariae were detected under the scales (89.9 per cent). Adult flukes were obtained from the small intestine of a rat, 15 days after infection with the metacercariae obtained from Z. platypus. These adult flukes were identified to be the same srecies as those obtained from human hosts. By this survey, new endemic areas of Metagonimus infection were discovered along the Hongcheon river basin and the main source of infection was the fresh water fish, Z. platypus.
TL;DR: The factors affecting the low reported prevalence rates of depressive disorders in Asia are clarified and the diagnoses given by ICD‐9 showed very interesting differences, which have importance for future international collaborative studies.
Abstract: A study aimed at the standardization of symptom evaluation of patients with depression was carried out as the first step in an extensive collaborative study on affective disorders between centers in Nagasaki, Shanghai and Seoul. This study was initiated in order to clarify the factors affecting the low reported prevalence rates of depressive disorders in Asia. No significant difference in evaluation of psychiatric symptoms was observed between the 3 centers. Nevertheless, the diagnoses given by ICD-9 showed very interesting differences. For any given case, Nagasaki tended to make a diagnosis of an affective psychosis depression, while Shanghai made a diagnosis of neurotic disorder. No significant tendency was observed in the Seoul center. These findings are discussed in terms of their importance for future international collaborative studies.
TL;DR: In this article, the variation in lattice constant and dielectric constant in the (Ba0.9Ca0.1) (Ti1−xSnx)O3 system have been investigated for compositions fromx = 0 tox = 0.20.
Abstract: The variation in lattice constant and dielectric constant in the (Ba0.9Ca0.1) (Ti1−xSnx)O3 system have been investigated for compositions fromx = 0 tox = 0.20. Thea axis lattice constant increases at room temperature as substitution of tin for titanium increases, while thec axis lattice constant decreases. The dielectric constant increases and the Curie temperature is shifted to lower temperature as the amount of tin increases.
TL;DR: Amberlite XAD copolymers have been used as adsorbents for organic substances and as supports for Chelating agent-impregnated resin (CIR) as mentioned in this paper.
Abstract: Amberlite XAD copolymers have been used as adsorbents for organic substances and as supports for Chelating agent-impregnated resin(CIR). The adsorption mechanism and behavior of 8-hydroxyquinoline (8HQ) and its derivatives on XAD resins have been investigated by interpreting the distribution coefficients (Kd) measured under various conditions. The logKd values of 8HQ and its four derivatives on XAD resins were found to increase up to the certain pH values, and then to decrease with increasing pH. The pH values having maximum logKd values are very close to their isoelectric points. The adsorption of 8HQ and its derivatives was due to molecular adsorption, because the adsorption became maximum when they existed as electrically neutral molecules. Amberlite XAD resins (XAD-2, -4 and -7) impregnated with chelating agents, such as 8HQ, 5, 7-dihalo-8-hydroxyquinoline (DXHQ) and 2-methyl-8-hydroxyquinoline (MHQ), have been applied as CIR resins to the adsorption, separation, concentration and recovery of metal ions (Cu, Cd, Ni, Zn, Pb, Hg and Fe) from the aqueous solutions. All CIR resins show relatively good resistance to leaching at the pH range of 3-10. The magnitude of adsorption capacity of CIR depends on the impregnating capacity of the CIR and the adsorption mole ratio at the optimum pH condition. The metal ions adsorbed by CIR were quantitatively recovered with 3-5M hydrochloric acid. Some examples of selective separation and concentration of metal ions were performed by using CIR resins.
TL;DR: Hyperpigmentation of the hands and feet developed in a 65–year–old Korean woman who had undergone a total gastrectomy and esophagojejunostomy due to early gastric cancer 7 years previously and a diagnosis of megaloblastic anemia due to vitamin B12 deficiency was made.
Abstract: Hyperpigmentation of the hands and feet developed in a 65-year-old Korean woman who had undergone a total gastrectomy and esophagojejunostomy due to early gastric cancer 7 years previously. A diagnosis of megaloblastic anemia due to vitamin B12 deficiency was made. In the areas of pigmentation, there were abnormally large nuclei in the keratinocytes. All of these findings were reversible upon the administration of vitamin B12. Ultrastructurally, there were many intracytoplasmic desmosomes, numerous aggregated bundles of tonofilaments, and highly condensed keratohyalin granules. The pathophysiologic mechanism of vitamin B12 deficiency associated with pigmentary disturbances and change of nuclear size is discussed.
TL;DR: A keratinolytic proteinase (KPase) which is regarded as an important factor in the pathogenesis of dermatophytosis was isolated and purified from Microsporum (M.) canis culture filtrates and circulating antibodies to this enzyme were detected.
Abstract: A keratinolytic proteinase (KPase) which is regarded as an important factor in the pathogenesis of dermatophytosis was isolated and purified from Microsporum (M.) canis culture filtrates. Enzyme-linked immunosorbent assay (ELISA) was used to determine the occurrence of circulating antibodies to this enzyme in sera samples from guinea pigs with superficial fungal infections caused by M. canis. Of sera samples from guinea pigs infected with M. canis, 75% were reactive within 10 weeks, however, those ELISA values were relatively low compared with those from guinea pigs immunized with KPase. The presence of circulating antibodies was first detected 2 weeks post inoculation with M. canis, corresponding to the period when the lesions were most severe. The titers of the ELISA antibodies reached a peak at 4 weeks; at that time the lesions had disappeared completely.
TL;DR: In this article, the first part of an extension of the Pirogov-Sinai theory of phase transitions at low temperatures, applicable to lattice systems with finite range interactions, to infinite range interactions is presented.
Abstract: This paper is the first part of an extension of the Pirogov-Sinai theory of phase transitions at low temperatures, applicable to lattice systems with finite range interactions, to infinite range interactions. Transforming the systems to a version of an interacting contour model, we develop a cluster expansion. Making appropriate assumptions about the interactions, we prove that for sufficiently low temperatures the expansion converges and the cluster property holds.
TL;DR: In this article, an equilibrium with intercity commuting has been analyzed, where either some residents or all residents of one city commute between cities, areas occupied by residents can be either connected or disconnected.
TL;DR: In this article, β-hydroxysulfony 1 sugars 4 and 5 were prepared by addition of phenylsulfonylmethide to a dialdose 3 and by oxidation of a sulfide sugar 8 with H 2 O 2 -H 2 SeO 2.
Journal Article•
TL;DR: The ultrastructural finding associated with overproductive proliferation of the endothelial cells leading to obliteration of the vascular lumen was the sporadical appearance of degenerated cells among proliferating endothelium cells in both cutaneous manifestations.
Abstract: We observed small dermal blood vessels embolized by thrombus at the sites of needle-prick reaction as well as erythema nodosum-like lesions in 4 patients with Behcet's disease, by means of electron microscopy. The ultrastructural finding associated with overproductive proliferation of the endothelial cells leading to obliteration of the vascular lumen was the sporadical appearance of degenerated cells among proliferating endothelial cells in both cutaneous manifestations. These degenerated cells showed contraction changes and may be involved in thrombogenesis.
TL;DR: In this paper, the algebraic and differential geometric structures of three and five-dimensional unified field theory were studied, with emphasis on the five dimensions of the Riemannian manifold.
Abstract: We study the algebraic and differential geometric structures of three- and five-dimensional*
g-unified field theory, with emphasis on the five-dimensional*
g-unified field theory, in which we derive a new set of powerful recurrence relations which hold in a five-dimensional generalized Riemannian manifoldX
5
, prove a necessary and sufficient condition for the existence and uniqueness of the solution of the system of the Einstein equations in the first two classes, and find a precise tensorial representation of the Einstein connection Γ
λ
in terms of*gνν
.