Showing papers by "Seoul National University published in 1983"
TL;DR: In this paper, a modified model for a deteriorating inventory system determining price and production levels is presented, where the exponential distribution is used to represent the distribution of the distribution over time.
Abstract: This paper presents a modified model for a deteriorating inventory system determining price and production levels. Specifically, the exponential distribution is used to represent the distribution o...
118 citations
TL;DR: In this paper, the problem of misuse of international ratio analysis with the hope that investors, security analysts, regulatory authorities, and international business researchers will become more aware of the pitfalls.
Abstract: Financial ratios, which may be appropriate measures of financial risk and return, are often misused when applied to foreign companies. This is due partly to explainable differences in international accounting principles. A more serious problem, however, is that even when ratios are based on U.S. GAAP, they are misinterpreted because the U.S. investor does not understand a particular foreign environment that influences all financial ratios in that environment. Using Japan and Korea as country examples, this paper analyzes the problem of misuse of international ratio analysis with the hope that investors, security analysts, regulatory authorities, and international business researchers will become more aware of the pitfalls.
78 citations
TL;DR: This is the first record on human E. hortense infection in Korea on the basis of echinostomatid eggs found from a 21-year old man during fecal examination in October 1983.
Abstract: Echinostomatid eggs were found from a 21-year old man, whole native village is Munkyong-gun, Kyongsangnam-do during fecal examination in October 1983. The eggs were detected again one week later concommitantly with the eggs of Clonorchis sinensis. He had no subjective symptoms related with these fluke infections. He was treated with praziquantel(Distocide(R)) 20 mg/kg in single dose and purgated with magnesium salt. One echinostomatid fluke and 4 adults of C. sinensis were collected from the diarrheal stools. After morphological observation, the echinostomatid fluke was identified as Echinostoma hortense Asada, 1926. This is the first record on human E. hortense infection in Korea.
50 citations
TL;DR: It was found that aucubin inhibited hepatic RNA and protein syntheses in vivo and might be responsible for protective activities against CCl4-induced liver damage.
Abstract: An iridoid glucoside, aucubin was isolated from Aucuba japonica leaves and its protective activities against CC14,-induced hepatotoxicity were evaluated by measuring the duration of hypnosis induced by hexobarbital after CCl4 challenge (0.2 ml/kg/day, po) and the levels of serum glutamic-oxalacetic (GOT) and serum glutamic-pyruvic transaminase (GPT). The duration of hypnosis for the saline control group, the CCI4 alone treated group and the aucubin plus CCI4 treated group was 24.8 ± 8.5, 60.5 ± 9.5 and 28.0 ± 3.2 min, respectively. Treatment of mice with aucubin also effectively protected against CCl4-induced increased serum GOT and GPT activities. It was found that aucubin inhibited hepatic RNA and protein syntheses in vivo. Such inhibitory effects of aucubin might be responsible for protective activities against CCI4-induced liver damage.
50 citations
TL;DR: Observations indicate that excision repair capacity and replicon size play major roles in the response of DNA replication to ultraviolet damage.
45 citations
TL;DR: Results suggest that poly(ADP-ribose) is important in the repair of DNA damage after exposure to alkylating agents and exercises a regulatory role in stabilizing chromatin structure whenever strand breaks occur in DNA.
Abstract: Benzamide and 3-aminobenzamide, inhibitors of poly(ADP-ribose) polymerase, synergistically enhanced the frequencies of unscheduled DNA synthesis and sister chromatid exchanges in Chinese hamster ovary (CHO) cells treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). These inhibitors also increased methyl methanesulfonate (MMS)- or MNNG-induced DNA strand breaks and significantly retarded the rejoining of strand breaks in CHO and HeLa S3 cells. These results suggest that poly(ADP-ribose) is important in the repair of DNA damage after exposure to alkylating agents and exercises a regulatory role in stabilizing chromatin structure whenever strand breaks occur in DNA.
43 citations
TL;DR: It is concluded that albino rats and mice are the most susceptible hosts for F. seoulensis infection among six kinds of laboratory animals examined.
Abstract: An experimental study was carried out to observe the susceptibility of several kinds of laboratory animals to Fibricola seoulensis infection, a diplostomatid fluke of mammals. The metacercariae were obtained from the viscera of the snakes, Natrix tigrina lateralis and 50-2,000 in number each was artificially fed to a total of 127 animals; albino rats, mice, dogs, cats, rabbits and chickens. After 3 days to 8 weeks the animals were sacrificed and the recovery rate of worms as well as their maturity was observed. The results are as follows: The overall wom recovery rates throughout the experimental period was highest in albino rats(40.0 %) followed by mice(33.9%), cats(20.9 %), dogs(11.4 %), rabbits(0.05 %) and chickens(0 %). However, the recovery rates in the same host decreased as infection progressed longer and variable by the amount of metacercariae given. From albino rats and mice, the highest recovery rates were obtained in 1,000 and 200 metacercariae infection groups repectively, and it is considerd that such amount should be the optimum dose for experimental infection of these animals. The main location of F. seoulensis in experimental animals was small intestine especially the duodenum. The maturity index (No. mature worms/No. examined) was 100% in albino rats and mice, while only 22.7% or 0% in dogs or cats respectively. From the results, it is concluded that albino rats and mice are the most susceptible hosts for F. seoulensis infection among six kinds of laboratory animals examined.
29 citations
TL;DR: In this paper, the influence of retained austenite on the work hardening behavior of dual-phase steel has been investigated with an Fe-0.07 C-1.8 Mn -1.4 Si steel.
Abstract: The influence of retained austenite on the work hardening behavior of dual-phase steel has been investigated with an Fe-0.07 C-1.8 Mn-1.4 Si steel. With a constant cooling rate of 5 °C per second after intercritical annealing at 780 °C, a significant quantity (about 8 vol pct) of retained austenite was obtained in the dual-phase microstructure. The retained austenite was classified morphologically into either ‘isolated’ or ‘capsulated’ types by TEM observation. The ‘capsulated’ type, which was found without a particular shape inside the microtwinned martensite particle, withstood much deformation by being protected by the surrounding martensite. While the ‘isolated’ type, which was found with an equiaxed shape and was isolated from martensite particles, was easily deformed by the first several percent plastic strain. The increase in work hardening rate, caused by the strain induced transformation of retained austenite to martensite, was ascribed to the contribution of the ‘isolated’ type, the major volume fraction of retained austenite. The effect of the retained austenite on the yielding of dual-phase steel was not indicated since the reduction in the volume fraction of retained austenite was negligible at the initial deformation stage.
27 citations
TL;DR: In this paper, the effect of void growth on the limit strain prediction was investigated and the classical yield function was used instead of more general form proposed recently, to assure the reliability of yield function, the analysis is confined to the steel sheets.
26 citations
TL;DR: In this article, the temperature dependence of electron paramagnetic resonance (EPR) results on [CH(FeCl 4 ) 0.061 ] x are reported, indicating metallic charge transport along the polyacetylene chain interrupted by the interfibril contact resistances and also dragged primarily by the dopant ions.
23 citations
TL;DR: From the roots of Patrinia scabiosaefolia, oleanolic acid, hederagenin, 3- O -α- l -arabinopyranosyl-oleanolic acid and a mixture of sitosterol and campesterol- d -glucosides were isolated as mentioned in this paper.
TL;DR: From these reinfection analyses, it is inferred that the principal mode of A. lumbricoides transmission in the surveyed rural area is likely to be of 'dooryard type', in which case childen and certain family members are more preferably reinfected.
Abstract: Epidemiological studies on the reinfection pattern of Ascaris lumbricoides were undertaken by means of blanket mass chemotherapy and worm collection in a rural village in Korea, during 1977~1980. The study objectives were to determine the age(sex)-specific reinfection rate during 2, 4, 6 and 12 months through repeated mass chemotherapy with pyrantel pamoate, and to observe the familial aggregation tendency of the reinfected cases. The results obtained are as follows: 1. The age(sex)-reinfection curve revealed that the reinfection rate is much higher in younger individuals than in olders in all of 4 kinds of interval chemotherapy groups. The highest reinfection rate and the highest burden of reinfected worms were observed in preschool childen, followed by primary school students. Such fluctuation in the age-specific reinfection rates was more pronounced in males than in females. 2. There was noted a significant tendency of familial aggregation among the reinfected cases. It is suggested that reinfection occurs never randomly but preferably to the members of certain household families. From these reinfection analyses, it is inferred that the principal mode of A. lumbricoides transmission in the surveyed rural area is likely to be of 'dooryard type', in which case childen and certain family members are more preferably reinfected. It is also suggested that the preschool childen should be included in the primary targets of mass control programme.
TL;DR: The results suggest the possibility that water extract of the mixture may have the lentinan like effect and ginseng polysaccharide may have stimulating effects on the general immune system.
Abstract: Polysaccharide fractions were prepared from Ginseng root,Mori Radicis Cortex (M.R.C.),Phellodendri Cortex (Ph.C.),Sappan Wood (S.W.) andTigli Semen (T.S.). Water extract was also prepared from the mixture of Ph.C., S.W. and T.S. Ginseng polysaccharide and water extract of the mixture showed marked antitumor activity against sarcoma 180. Ginseng polysaccharide showed a mild increasing effect on the number of circulating leucocytes and a marked increasing effect on the number of plaque forming cells (PFC). Polysaccharides from ginseng root, S.W., Ph.C.+T.S. and water extract of the mixture showed dramatic inducing activities of peritoneal exudate cells (PEC), polymorphonuclear leucocytes (PMN) and macrophages. These results suggest the possibility that water extract of the mixture may have the lentinan like effect and ginseng polysaccharide may have stimulating effects on the general immune system.
TL;DR: Five cases of Diphyllobothrium latum infection were proved by collection of worms after treatment with bithionol, niclosamide or praziquantel, during 1975~1983 in Korea, with patients aged 10-64 years residing in Seoul or Wando-gun, Chollanam-do, Korea.
Abstract: Five cases of Diphyllobothrium latum infection were proved by collection of worms after treatment with bithionol, niclosamide or praziquantel, during 1975~1983. The patients were 4 males and one female aged 10-64 years residing in Seoul or Wando-gun, Chollanam-do, Korea. All of them remembered the history of eating several kinds of raw marine fish and 2 persons said they ate the raw flesh of perch, Lateolabrax japonicus. Three among them experienced abdominal pain, 2 natural discharge of a chain of segments, but none revealed any sign of anemia. The average egg size in stool varied 59-67 x 41~48 micrometer according to cases. The eggs were characterized by ovoid to elliptical shape, terminal operculum, and distinct abopercular protuberance. One naturally discharged segment (30 cm) and 4 complete strobilae (320~680 cm) with scolices obtained after treatments were examined. The morphological characters of proglottids such as rosette-form uterus with 3~6 loops, vaginal pore included in the cirrus sac, separated seminal vesicle from cirrus sac etc. were all compatible with D. latum. These are the 7th~11th cases of D. latum infection proved by worms in Korea.
TL;DR: The results suggest that ethanol extract of Aucuba japonica protects CCl 4 hepatotoxicity at a site in the chain events leading to necrosis but not the activation step of CCl4 to X CCl3 and X C1 free radicals.
Abstract: Pretreatment of rats with ethanol extract from leaves of Aucuba japonica (600 mg/kg/day, po) for two days protected against CCl4-induced depression in plasma disappearance and biliary excretion of injected sulfobromophthalein (BSP) determined 24 hr after the CCI4 challenge (0.5 ml/kg, ip). Percent recovery of BSP in bile in 60 min for control, CCI4, extract + CCI4 treated rats was 66.8 ± 1.9, 56.2 ± 1.4, and 68.9 ± 2.2, respectively. Pretreatment of the extract also protected CCl4-induced increased serum glutamic-pyruvic transaminase activity and liver necrosis as demonstrated by histological evaluations. However, pretreatment of the extract did not modify the intensity of CCl4-induced lipid peroxidation process or cytochrome P-450 destruction. The results suggest that ethanol extract of Aucuba japonica protects CCI4 hepatotoxicity at a site in the chain events leading to necrosis but not the activation step of CCI4 to-CC13 and CI free radicals.
TL;DR: Two major and two minor polyacetylenes were isolated from fresh Korean ginseng roots as discussed by the authors, which were determined by UV, IR, 1 H NMR and 13 C NMR, mass spectra and elemental analysis.
TL;DR: Chromatographic separation of the butanol-soluble part of the methanol extract of Typha latifolia leaves resulted in the isolation of a new flavonoid, 3,3′-di-O -methylquercetin 4′- O -glucoside.
TL;DR: Praziquantel(Distocide), the Korean product, was tested for its safety and efficacy in treatment of Clonorchis sinensis infection during the period from April to September, 1983 in Korea and it was concluded that Distocide is as effective and safe as Biltricide(R) and highly recommendable in treatment.
Abstract: Praziquantel(Distocide), the Korean product, was tested for its safety and efficacy in treatment of Clonorchis sinensis infection during the period from April to September, 1983 in Korea. A total of 55 egg positive cases were selected and treated with the regimen of 25 mg/kg t.i.d. for 1 day (total 75 mg/kg). The follow-up stool examination was done in 47 cases by cellophane think smear and Stoll's egg counting techniques. The 8 uncured cases were treated again with the same regimen. The laboratory tests for blood picture and liver function were done in 27 cases and compared before and after the treatment. The results obtained are as follows: After single course treatment, the cure and egg reduction rates were 83.0% and 99.1% respectively. With the second treatment, excellent results of 100% in both rates were obtained. Several kinds of side effects such as dizziness, headache, etc. were complained by 29 cases (61.7%), however, those were so mild and transient that no special treatment was necessary. No significant chang in laboratory findings was recognizable before and after the treatment. From the above results, it is concluded that Distocide is as effective and safe as Biltricide(R) and highly recommendable in treatment of C. sinensis infection.
TL;DR: From ether-soluble neutral fraction of the whole plant ofeperomia pellucida (L) HBK (Piperaceae), 4,7-dimethoxy-5-(2-propenyl)-1, 3-benzodioxole or apiol, and three phytosterols, campesterol, stigmasterol and β-sitosterol were isolated and characterized by spectral data.
Abstract: From ether-soluble neutral fraction of the whole plant ofPeperomia pellucida (L) HBK (Piperaceae), 4,7-dimethoxy-5-(2-propenyl)-1, 3-benzodioxole or apiol, in a liquid state, 2,4,5,-trimethoxy styrene, mp 138°, and three phytosterols, campesterol, stigmasterol and β-sitosterol, were isolated and characterized by spectral data.
TL;DR: Inverted amphibian embryos were employed for an analysis of pattern formation in early embryogenesis and observations should eventually be useful in formulating models to account for the manner in which various regions of the amphibian egg cytoplasm generate early embryonic patterns.
Abstract: Inverted amphibian embryos were employed for an analysis of pattern formation in early embryogenesis. Axolotl ( Ambystoma ) and Xenopus eggs were inverted prior to the first cleavage division and permitted to develop upside down to the early gastrulation stage. In both cases the cleavage patterns of the animal and vegetal hemispheres were reversed. By gastrulation, however, developmental arrest began, and no inverted embryos developed beyond neurulation. The state of competence of the animal and vegetal hemisphere cells of inverted embryos was examined in a series of tissue transplantations, usually into genetically marked (albino) hosts. In all cases the developmental competence of the original animal and vegetal hemisphere cells of inverted embryos had been reversed. For example, the egg's original vegetal hemisphere developed into various neural structures.
Those observations should eventually be useful in formulating models to account for the mannerin which various regions of the amphibian egg cytoplasm generate early embryonic patterns.
TL;DR: In this paper, the deux expressions for l'energie libre molaire partielle en exces de melange dans les solutions ternaires determinees par Jacob et Fitzner et Lee basees sur le parcours de composition de plus courte distance ne sont pas les memes.
TL;DR: This patient was successfully treated with sodium antimony gluconate (Pentostam(R), and follow up liver biopsy showed focal fibrous scar and otherwise normal liver without demonstrable organism.
Abstract: An imported case of Kala-azar in a 26-year-old Korean man is reported. The diagnosis was made by liver needle biopsy. Amastigotes were seen in Kupffer cells under light microscope, and their characteristic ultrastructural features were recognized under the electron microscope. This case represents an imported disease from Saudi Arabia where the patient spent one year as a construction worker, 8 months before the onset of the disease. This report also signifies the second description of Kala-azar in Korea, and the first case of Kala-azar imported from Saudi Arabia. This patient was successfully treated with sodium antimony gluconate (Pentostam(R)), and follow up liver biopsy showed focal fibrous scar and otherwise normal liver without demonstrable organism.
TL;DR: Examination of the individual and joint effects of community, housing and household on the levels of satisfaction, dissatisfaction, pleasure, and worry which Korean people experience shows clear trends in quality of life.
Abstract: Both in industrialized and industrializing countries environment is widely believed to be an important contributing source of the quality which people seek to bring to their lives. Yet, quality of life researchers have made little effort to determine the exact nature of environmental effects on perceptions of quality of life. This paper examines the individual and joint effects of community, housing and household on the levels of satisfaction, dissatisfaction, pleasure, and worry which Korean people experience.
01 Jul 1983
TL;DR: In this article, absolute measurements of the viscosity of carbon monoxide (CO) with krypton (Kr), carbon dioxide (CO2), methane (CH4) and carbon tetra-fluoride (CF4) have been carried out in an oscillating-disk viscometer at a pressure of 0.1 MPa in the temperature range 25-200 °C.
Abstract: The paper reports new, absolute measurements of the viscosity of carbon monoxide (CO) with krypton (Kr), carbon dioxide (CO2), methane (CH4) and carbon tetra-fluoride (CF4). The measurements have been carried out in an oscillating-disk viscometer at a pressure of 0.1 MPa in the temperature range 25–200 °C. The accuracy is estimated to lie between ± 0.1 % and ± 0.2%. The data have been correlated by means of the two-parameter extended law of corresponding states. They have been utilized to derive binary diffusion coefficients. This paper is a supplement to an earlier publication on mixtures with He, Ne, Ar, and N2. The great similarity between the viscosity of binary mixtures with N2 and CO, respectively, is confirmed to a high degree of accuracy.
TL;DR: Experimental diets consisting of two levels of total phosphorus and three different treatments of supplemental sodium affected egg production more strongly than sodium chloride did and addition of sodium bicarbonate to the low phosphorus diet significantly (P less than .05) decreased feed consumption of the hen.
TL;DR: The epidemiological relationship between the current prevalence and monthly reinfection rate of Ascaris lumbricoides was observed in rural communities in Korea by means of blanket mass chemotherapy and worm collection and it was inferred that the majority of reinfected worms in human host turn over every 7~8 months.
Abstract: The epidemiological relationship between the current prevalence and monthly reinfection rate of Ascaris lumbricoides was observed in rural communities in Korea by measns of blanket mass chemotherapy and worm collection for measurement of the prevalence and reinfection rates. During the period from 1975 to 1980, a total of 4,466 inhabitants in 10 different localities were treated with 10 mg/kg of pyrantel pamoate and 2 days' whole stools were collected from 2,547 inhabitants. The stools were examined for the presence of expelled adult and/or young worms, which represent the prevalence and reinfection rates for past 2 months respectively. After then, the obtained rates were correlated each other applying the time-prevalence curve proposed by Hayashi. It was observed that the prevalence (overall worm positive rate) and worm burden per individual ranged by areas from 13.6 to 72.3% and 1.4~10.2 respectively. The calculated monthly reinfection rates (X) (from young worm positive rates) according to areas were in the range, 2.6~16.2%, and clearly correlated with the current prevalence (Y) under the equation, Y=1-(1-X)(7.2) where 7.2 is time in month. The equation means that after one time mass chemotherapy the period needed to attain equilibrium of prevalence again would be about 7~8 months. And it is inferred that the majority of reinfected worms in human host turn over every 7~8 months.
TL;DR: The interaction of riboflavin-2',3',4',5'-tetrabutyrate with salicylic acid, aspirin, and salicylamide has been spectroscopically investigated to determine the binding mechanism.
TL;DR: A total of 2,026 leprosy patients of the National Sorokdo Hospital was examined their intestinal parasites by cellophane thick smear method in January 1983 and revealed significantly high egg positive rate of T. trichiura, however, A. lumbricoides was found to be controlled considerably by repeated chemotherapy during past 3 years.
Abstract: A total of 2,026 leprosy patients of the National Sorokdo Hospital was examined their intestinal parasites by cellophane thick smear method in January 1983. The egg positive cases of Taenia spp. were treated with bithionol and the segments of Taenia were collected for species identification. The results were as follows: 1. Total egg positive rate of any kind helminth was 78.2 % and cumulative total was 85.2 %. The egg positive rate for each helminth was as follow; Taenia spp. 3.4 %, Ascaris lumbricoides 4.5 %, Trichuris trichiura 72.l %, Clonorchis sinensis 2.8 % and other 0.05 %. 2. A total of 66 Taenia egg positive cases was treated; out of them proglottids of Taenia were collected from 26 cases. All of the collected worms were identified as T. saginata. The results revealed significantly high egg positive rate of T. trichiura. However, A. lumbricoides was found to be controlled considerably by repeated chemotherapy during past 3 years. If chemotherapeutic agent is replaced with oxantel-pyrantel tablet, better result is expected. No clue was found for prevalence of T. solium from both human and the pig in the island.