• Title/Summary/Keyword: 길이비

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Equilibrium Fractionation of Clumped Isotopes in H2O Molecule: Insights from Quantum Chemical Calculations (양자화학 계산을 이용한 H2O 분자의 Clumped 동위원소 분배특성 분석)

  • Sehyeong Roh;Sung Keun Lee
    • Korean Journal of Mineralogy and Petrology
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    • v.36 no.4
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    • pp.355-363
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    • 2023
  • In this study, we explore the nature of clumped isotopes of H2O molecule using quantum chemical calculations. Particularly, we estimated the relative clumping strength between diverse isotopologues, consisting of oxygen (16O, 17O, and 18O) and hydrogen (hydrogen, deuterium, and tritium) isotopes and quantify the effect of temperature on the extent of isotope clumping. The optimized equilibrium bond lengths and the bond angles of the molecules are 0.9631-0.9633 Å and 104.59-104.62°, respectively, and show a negligible variation among the isotopologues. The calculated frequencies of the modes of H2O molecules decrease as isotope mass number increases, and show a more prominent change with varying hydrogen isotopes over those with oxygen isotopes. The equilibrium constants of isotope substitution reactions involving these isotopologues reveal a greater effect of hydrogen mass number than oxygen mass number. The calculated equilibrium constants of clumping reaction for four heavy isotopologues showed a strong correlation; particularly, the relative clumping strength of three isotopologues was 1.86 times (HT18O), 1.16 times (HT17O), and 0.703 times (HD17O) relative to HD18O, respectively. The relative clumping strength decreases with increasing temperature, and therefore, has potential for a novel paleo-temperature proxy. The current calculation results highlight the first theoretical study to establish the nature of clumped isotope fractions in H2O including 17O and tritium. The current results help to account for diverse geochemical processes in earth's surface environments. Future efforts include the calculations of isotope fractionations among various phases of H2O isotopologues with a full consideration of the effect of anharmonicity in molecular vibration.

The Sangsaeng Ecological Theory of Daesoon Jinrihoe: Focusing on the Meaning of Sangsaeng (대순진리회의 상생생태론 연구 - 상생의 의미를 중심으로 -)

  • Kim Gui-man
    • Journal of the Daesoon Academy of Sciences
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    • v.48
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    • pp.375-406
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    • 2024
  • This study aims to define the meaning of 'Sangsaeng (mutual beneficence)' within the context of 'Sangsaeng ecological theory,' a form of discourse of that has emerged from Daesoon Jinrihoe's perspective on ecology. Sangsaeng ecological theory applies the concept of interdependence to ecology in order to explain how Sangsaeng, which is commonly used as an ethical system for humans, can be applied to the realm of ecology such that it extends its scope of application to include non-human beings. Interdependence, when applied to ecology, is formed via relationships between individuals. Such relationships can be positive, negative, or neutral, and the type of interdependence that emerges can be competitive, predatory, parasitc, and symbiotic. Even if the relationship between individuals ends negatively, it can still exert a positive effect on the ecosystem. Consequently, all of these produce a type of 'dependence'. However, relationships that end negatively can generate grievances, and from the perspective of Sangsaeng ethics, this type of interdependence is to be avoided. Therefore, by way of contrast, ecological Sangsaeng may include both relationships of positive interdependence and relationships of predation, parasitism, and competition in so far as there no grievances. Ecological theory requires a perspective that enables an understand of the relationship between nature and humans in an integrated way that does not separate them. One view of universe, known as Cheonji-saengin-yongin (Heaven and Earth give produce humans make use of them) provides insights into the relationship between the universe and humans and nature and humans from an interdependent perspective. Heaven and Earth take humans as the basis of their existence, and only after humans discover the law of nature and the sacredness behind it can a deep interdependence between Heaven and Earth and humans and nature and humans be established. However, as modern humans emerge, the interdependence between Heaven and Earth and humans collapses as they destroy nature and lower the authority of Shindo (divine order). Haewon Sangsaeng (the resolution of grievances for mutual beneficence) and Boeun Sangsaeng (the reciprocation of favors for mutual beneficence) is the solution to reestablish the interdependence that has been disconnected between Heaven and Earth and humans and nature and humans. The practice of Haewon Sangsaeng through Gongbu rituals is the way to restore interdependence between nature and humans. The process of humans achieving Dotong (mastery of the Dao) through religious practices is the practice of Boeun Sangsaeng, and humans will be reborn into Injon (Human Nobility or 'divine humans') with ecological nature and enjoy an eternal interdependent relationship with nature. In summary, Sangsaeng in the context of Sangsaeng ecological theory is the idea and practice of allowing nature and humans to restore their interdependence and live on eternally.

Analysis of p53 and Retinoblasoma(Rb) Gene Polymorphisms in Relation to Lung Cancer in Koreans (한국인 폐암 환자에 대한 p53 및 Rb유전자의 다형성 분석)

  • Lee, Kyung-Sang;Sohn, Jang-Won;Yang, Suck-Chul;Yoon, Ho-Joo;Shin, Dong-Ho;Park, Sung-Soo;Lee, Jung-Hee;Lee, Chun-Geun;Cho, Youl-Hee
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.3
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    • pp.534-546
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    • 1997
  • Background : The p53 and retinoblastoma(Rb) tumor suppressor genes are associated with the pathogenesis of several types of human cancer. Substantial proportion of the primary lung cancers or cell lines have been reported to have the p53 and/or the Rb gene mutations. But, so far there is no report on the analysis of the Rb gene polymorphism as one of the genetic susceptibility marker. This study was undertaken to establish the gene frequencies of the polymorphic genotypes of the p53 and Rb genes in Koreans to evaluate the possible involvement of these genotypes as a risk factor of lung cancer. Methods : In this study 145 controls without previous and present tumor history and 128 lung cancer patients were subjected to analysis. The two intragenic polymorphisms of the p53 gene(exon 4/ AccII, intron 6/MspI) and one intron 17/XbaI polymorphism of the Rb gene were analysed by the method of polymersae chain reaction- restriction fragment length polymorphisms(PCR-RFLPs). The genotype of the intron 3/16 bp repeat polymorphism of p53 was determined by PCR and direct gel electrophoresis. Results : There were no significant differences in the genotype distributions of the p53 gene between lung cancer patients and controls. But heterozygotes(Arg/Pro) of the exon 4/AccII polymorphisms were slightly over-represented than controls, especially in the Kreyberg type I cancer, which was known to be associated with smoking. The intron 3/16 bp duplication and the intron 6/MspI polymorphisms were in complete linkage disequilibrium. About 95% of the individuals were homozygotes of the common alleles both in the 16 duplication and MspI polymorphisms, and no differences were deteced in the genotype distributions between lung cancer patients and controls. Overall genotype distributions of the Rb gene polymorphisms between lung cancer patients and controls were not significantly different However, the genotype distributions in the Kreyberg type I cancer were significantly different from those of controls(p = 0.0297) or adenocarcinomas(p = 0.0008). It was noticeable that 73.4% of the patients with adenocarcinomas were heterozygotes(r1/r2) whereas 39.2% of the Kreyberg type I cancer were heterozygous at this polymorphisms. In the lung cancer patients, significant differences were also noted between the high dose smokers and low dose smokers including non-smokers(p = 0.0258). The relative risk to Kreyberg type I cancer was significantly reduced in the individuals with the genotype of r1/r2(odds ratio = 0.46, 95% C.I. = 0.25-0.86, p = 0.0124). The combined genotype distribution of the exon 4 AccII of the p53 and the intron 17 Rb gene polymorphisms in Kreyberg type I cancers were significantly different from dose of controls or adenocarcinomas. The highest odds ratio were observed in the individuals with the genotypes of Arg/Pro and r2/r2(odds ratio = 1.97,95% C.I. = 0.84-4.59) and lowest one was in the patients with Arg/Arg, r1/r2 genotype(odds ratio = 0.54, 95% C.I. = 0.25-1.14). Conclusion : The p53 and the Rb gene polymorphisms modulate the risk of smoking induced lung cancer development in Koeans. However, the exact mechanism of risk modulation by these polymorphism remains to be determined. For more discrete clarification of associations between specific genotypes and lung cancer risk, the evaluations of these polymorphisms in other ethnics and more number of patients will be needed.

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A Study on the Excavated Sab(a funeral fan) from Lime-filled Tomb and Lime-layered Tomb during the Joseon Dynasty (조선시대 회격·회곽묘 출토 삽(翣)에 대한 고찰)

  • Yi, Seung Hae;An, Bo Yeon
    • Korean Journal of Heritage: History & Science
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    • v.41 no.2
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    • pp.43-59
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    • 2008
  • Sap(?, a funeral fan) is a funeral ceremonial object used in association with a Confucian ceremonial custom, which was crafted by making a wooden frame, attaching a white cloth or a thick paper onto it, drawing pictures on it, and making a holder for a handle. According to Liji(Records of Rites), Sap was used since the Zhou Dynasty, and these Chinese Sap examples are no big different than the Korean Sap examples, which were described in Joseon Wangjo Sillok(Annals of the Joseon Dynasty), Gukjo Oryeui(the Five Rites of the State), and Sarye Pyeollam(Handbook on Four Rituals). This study explored Sap excavated in lime-filled tombs and lime-layered tombs of aristocrats dating back to Joseon, as well as their historical records to examine Sap's characteristics according to their examples, manufacturing methods, and use time. The number and designs of Sap varied according to the deceased' social status aristocrats used mainly one pair of 亞-shaped Bulsap, and a pair of Hwasap with a cloud design depicted on it. A Sap was wrapped twice with Chojuji paper or Jeojuji paper, and for the third time with Yeonchangji paper. Then, it was covered with a white ramie, a hemp, a cotton, a silk satin, etc. Bobul(an axe shape and 亞-shape design) was drawn on both sides of Sap, and a rising current of cloud was drawn at the peripheral area mainly with red or scarlet pigments. Sap, which were excavated from aristocrats'lime-filled and lime-layered tombs, are the type of Sap which were separated from its handle. These excavated Sap are those whose long handles were burnt during the death carriage procession, leaving Sap, which later were erected on both sides of the coffin. The manufacturing process of excavated relics can be inferred by examining them. The excavated relics are classified into those with three points and those with two points according to the number of point. Of the three-point type(Type I), there is the kind of relic that was woven into something like a basket by using a whole wood plate or cutting bamboo into flat shapes. The three-point Sap was concentrated comparatively in the early half of Joseon, and was manufactured with various methods compared with its rather unified overall shape. In the meantime, the two-point Sap was manufactured with a relatively formatted method; its body was manufactured in the form of a rectangle or a reverse trapezoid, and then its upper parts with two points hanging from them were connected, and the top surface was made into a curve(Type II) or a straight line(Type III) differentiating it from the three-point type. This manufacturing method, compared with that of the three-point type, is simple, but is not greatly different from the three-point type manufacturing method. In particular, the method of crafting the top surface into a straight line has been used until today. Of the examined 30 Sap examples, those whose production years were made known from the buried persons'death years inscribed on the tomb stones, were reexamined, indicating that type I was concentrated in the first half of the $16^{th}$ century. Type II spanned from the second half of the $16^{th}$ century to the second half of the $17^{th}$ century, and type III spanned from the first half of the $17^{th}$ century to the first half of the $18^{th}$ century. The shape of Sap is deemed to have changed from type I to type II and again from type II to type III In the $17^{th}$ century, which was a time of change, types II and III coexisted. Of the three types of Sap, types II and III re similar because they have two points; thus a noteworthy transit time is thought to have been the middle of the $16^{th}$ century. Type I compared with types II and III is thought to have required more efforts and skills in the production process, and as time passed, the shape and manufacturing methods of Sap are presumed to have been further simplified according to the principle of economy. The simplification of funeral ceremonies is presumed to have been furthered after Imjinwaeran(Japanese invasion of Joseon, 1592~1598), given that as shown in the Annals of King Seonjo, state funerals were suspended several times. In the case of Sap, simplification began from the second half of the $16^{th}$ century, and even in the $18^{th}$ century, rather than separately crafting Sap, Sap was directly drawn on the coffin cover and the coffin. However, in this simplification of form, regulations on the use of Sap specified in Liji were observed, and thus the ceremony was rationally simplified.

Studies on Garlic Mosaic Virus -lts isolation, symptom expression in test plants, physical properties, purification, serology and electron microscopy- (마늘 모자이크 바이러스에 관한 연구 -마늘 모자이크 바이러스의 분리, 검정식물상의 반응, 물리적성질, 순화, 혈청반응 및 전자현미경적관찰-)

  • La Yong-Joon
    • Korean journal of applied entomology
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    • v.12 no.3
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    • pp.93-107
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    • 1973
  • Garlic (Allium sativum L.) is an important vegetable crop for the Korean people and has long been cultivated extensively in Korea. More recently it has gained importance as a source of certain pharmaceuticals. This additional use has also contributed to the increasing demand for Korean garlic. Garlic has been propagated vegetatively for a long time without control measures against virus diseases. As a result it is presumed that most of the garlic varieties in Korea may have degenerated. The production of virus-free plants offers the most feasible way to control the virus diseases of garlic. However, little is known about garlic viruses both domestically and in foreign countries. More basic information regarding garlic viruses is needed before a sound approach to the control of these diseases can be developed. Currently garlic mosaic disease is most prevalent in plantings throughout Korea and is considered to be the most important disease of garlic in Korea. Because of this importance, studies were initiated to isolate and characterize the garlic mosaic virus. Symptom expression in test plants, physical properties, purification, serological reaction and morphological characteristics of the garlic mosaic virus were determined. Results of these studies are summarized as follows. 1. Surveys made throughout the important garlic growing areas in Korea during 1970-1972 revealed that most of the garlic plants were heavily infected with mosaic disease. 2. A strain of garlic mosaic virus was obtained from infected garlic leaves and transmitted mechanically to Chenopodium amaranticolor by single lesion isolation technique. 3. The symptom expression of this garlic mosaic virus isolate was examined on 26 species of test plants. Among these, Chenopodium amaranticolor, C. quince, C. album and C. koreanse expressed chlorotic local lesions on inoculated leaves 11-12 days after mechanical inoculation with infective sap. The remaining 22 species showed no symptoms and no virus was recovered from them whet back-inoculated to C. amaranticolor. 4. Among the four species of Chtnopodium mentioned above, C. amaranticolor and C. quinoa appear to be the most suitable local lesion test plants for garlic mosaic virus. 5. Cloves and top·sets originating from mosaic infected garlic plants were $100\%$ infected with the same virus. Consequently the garlic mosaic virus is successively transmitted through infected cloves and top-sets. 6. Garlic mosaic virus was mechanically transmitted to C, amaranticolor when inoculations were made with infective sap of cloves and top-sets. 7. Physical properties of the garlic mosaic virus as determined by inoculation onto C. amaranticolor were as follows. Thermal inactivation point: $65-70^{\circ}C$, Dilution end poiut: $10^-2-10^-3$, Aging in vitro: 2 days. 8. Electron microscopic examination of the garlic mosaic virus revealed long rod shaped particles measuring 1200-1250mu. 9. Garlic mosaic virus was purified from leaf materials of C. amaranticolor by using two cycles of differential centrifugation followed by Sephadex gel filtration. 10. Garlic mosaic virus was successfully detected from infected garlic cloves and top-sets by a serological microprecipitin test. 11 Serological tests of 150 garlic cloves and 30 top-sets collected randomly from seperated plants throughout five different garlic growing regions in Korea revealed $100\%$ infection with garlic mosaic virus. Accordingly it is concluded that most of the garlic cloves and top-sets now being used for propagation in Korea are carriers of the garlic mosaic virus. 12. Serological studies revealed that the garlic mosaic virus is not related with potato viruses X, Y, S and M. 13. Because of the difficulty in securing mosaic virus-free garlic plants, direct inoculation with isolated virus to the garlic plants was not accomplished. Results of the present study, however, indicate that the virus isolate used here is the causal virus of the garlic mosaic disease in Korea.

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Strain Improvement of the Genus Pleurotus by Protoplast Fusion (원형질체(原形質體) 융합(融合)에 의한 느타리버섯속(屬)의 품종개발(品種開發))

  • Yoo, Young-Bok;You, Chang-Hyun;Cha, Dong-Yeul
    • The Korean Journal of Mycology
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    • v.21 no.3
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    • pp.200-211
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    • 1993
  • Somatic hybrids of Pleurotus florida ASI 2016 and Pleurotus ostreatus ASI 2018 were obtained by protoplast fusion. The 40 fusants($P1{\sim}P40$) was examined for the yield on fermented and pasteurized rice straw in a tray. The carpophore yield of them were showed as the range of $27.0{\sim}155.2$, based on parental values of 100(ASI 2018), The pilei of fusants between orange white colored P. florida and dark grey colored P. ostreatus had mixed colors in the young stage. Other breeding programmes were performed to improve new varieties with high yield and good quality. A new oyster mushroom variety, Wonhyeongneutaribeosus(P72), was developed at the Agricultural Sciences Institute, Rural Development Administration in 1990. This P.florida-ostreatus-ostreatus hybrid P72 was selected from 38 protoplast fusion products($P41{\sim}P78$) between P.florida-ostreatus recombinant P5-M 43-arg rib and P. ostreatus ASI 2-13-0 2001-19-pro orn. The yield indexes of 38 hybrids ranged $40.5{\sim}152.7$ compared with the parental values of 100(ASI 2001). Hybrid P72 was characterized by the large fruiting bundle of semispherical shape with long stipe and by the small and circular pileus, resulting in lower harvesting cost. A significant increase in carpophore production was observed in somatic hybrids of protoplasts due to heterosis. A comparision of hybrid with parents P72 was made using isozyme analysis. The esterase banding patterns could be characterized by new bands in the hybrids. Seven fusion products of four crosses between P.florida ASI 2016 and P. ostreatus ASI 2018 were analysed with respect to the distribution of progenies and segregation of gene markers by random basidiospore analysis. Segregation of alleles should yield progeny of four genotypes in a Mendelian ratio of 1 : 1 : 1 : 1 for prototrophs, auxotrophs of one parental type, auxotrophs of the other parental type, and auxotrophic recombinants, respectively. However, five fusants of them did not detect one parental, P.ostreatus, type. Basidiospores could yield progeny of 16 genotypes in the cross of one of the recombinant P5-M43-arg $rib{\times}P. ostreatus$ ASI 2-13-pro orn but the segregants of three fusants were not detected clearly. The allele ratio of loci could be expected 1 : 1 : 1 : 1 for arg, rib, pro and orn. The ratio, however, would be changed to 4 : 1 : 1 : 1 with increasing proportion of argo In almost all the fusants, prototrophic recombinants were recovered in large numbers against auxotrophic markers. Parental genotypes were recovered with the recombinant progeny amounting to $38.68{\sim}99.56%$. The analysis provides proof of heterokaryosis and strong evidence for haploidy of vegetative nuclei, a sexual cycle consisting of nuclear fusion and meiosis.

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The Irradiated Lung Volume in Tangential Fields for the Treatment of a Breast (유방암의 접선 조사시 피폭 폐용적)

  • Oh Young Taek;Kim Juree;Kang Haejin;Sohn Jeong Hye;Kang Seung Hee;Chun Mison
    • Radiation Oncology Journal
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    • v.15 no.2
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    • pp.137-143
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    • 1997
  • Purpose : Radiation pneumonitis is one of the complications caused by radiation therapy that includes a Portion of the lung tissue. The severity of radiation induced pulmonary dysfunction depends on the irradiated lung volume, total dose, dose rate and underlying Pulmonary function. It also depends on whether chemotherapy is done or not. The irradiated lung volume is the most important factor to predict the pulmonary dysfunction in breast cancer Patients following radiation therapy. There are some data that show the irradiated lung volume measured from CT scans as a part of treatment Planning with the tangential beams. But such data have not been reported in Korea. We planned to evaluate the irradiated lung volume quantitatively using CT scans for the breast tangential field and search for useful factors that could Predict the irradiated lung volume Materials and Methods : The lung volume was measured for 25 patients with breast cancer irradiated with tangential field from Jan.1995 to Aug.1996. Parameters that can predict the irradiated lung volume included; (1) the peruendicular distance from the Posterior tangential edge to the posterior part of the anterior chest wall at the center of the field (CLD) ; (2) the maximum perpendicular distance from the posterior tangential field edge to the posterior Part of the anterior chest wall (MLD) ; (3) the greatest perpendicular distance from the Posterior tangential edge to the posterior part of anterior chest wall on CT image at the center of the longitudinal field (GPD) ; (4) the length of the longitudinal field (L). The irradiated lung volume(RV), the entire both lung volume(EV) and the ipsilateral lung volume(IV) were measured using dose volume histogram. The relationship between the irradiated lung volume and predictors was evaluated by regression analysis. Results :The RV is 61-279cc (mean 170cc), the RV/EV is $2.9-13.0\%\;(mean\;5.8\%)$ and the RV/IV is $4.9-29.0\%\;(mean\;12.2\%)$. The CLD, the MLD and the GPD ave 1.9-3.3cm, 1.9-3.3cm and 1.4-3.1cm respectively. The significant relations between the irradiated lung volume such as RV. RV/EV, RV/IV and parameters such as CLD, MLD, GPO, L. $CLD\timesL,\;MLD\timesL\;and\;GPD\timesL$ are not found with little variances in parameters. The RV/IV of the left breast irradiation is significantly larger than that of the right but the RV/EVS do not show the differences. There is no symptomatic radiation pneumonitis at least during 6 months follow up. Conclusion : The significant relationship between the irradiated lung volume and predictors is not found with little variation on parameters. The irradiated lung volume in the tangential held is liss than $10\%$ of entire lung volume when CLO is less than 3cm. The RV/IV of the left tangential field is larger than that of the right but there was no significant differences in RV/EVS. Symptomatic radiation pneumonitis has not occurred during minimum 6 months follow up.

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Anatomical Studies on Tumorous Tissue Formed in a Stem of Ailanthus altissima Swingle by Artificial Banding and Its Subsequent Removing Treatment -Characters of Individual Elements- (인위적(人爲的)인 밴드결체(結締) 및 해체처리(解締處理)로 형성(形成)된 가죽나무(Ailanthus altissima Swingle) 수간(樹幹)의 종양조직(腫瘍組織)에 관한 해부학적(解剖學的) 연구(硏究) -조직(組織) 구성세포(構成細胞)의 특성(特性)-)

  • Eom, Young Geun;Lee, Phil Woo
    • Journal of Korean Society of Forest Science
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    • v.78 no.3
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    • pp.287-301
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    • 1989
  • A tree of Ailanthus altissima Swingle was fastened with a plastic band, 19mm wide, around the stem 180cm above ground level and was left to grow under this condition for one year, By removal of this band the tumorous tissue gradually developed and the tree bearing distinct tumorous tissue, an overgrowth surrounding the stem, was harvested two years after the band removal. For the investigation of this tumorous part and its comparison with adjacent normal parts in the anatomical features of individual elements, the tumorous part and parts directly and 40cm above and below the tumorous part were obtained from the tree. The tumor wood having remarkably wider growth increment occurred in the 3rd growth ring the first year after removal of the fastened band, and the barrier zone which delimited the discolored wood from the normal-colored wood inwards appeared u1 the intra-2nd growth ring produced during the fastened period in the tumorous part and the false ring-like zones equivalent to barrier Zone were shown in the normal-colored 2nd growth rings of the parts directly and 40cm above and below the tumorous part, as well. The tumor wood, the 3rd growth ring, and proportion of the 2nd growth ring formed after barrier zone in the tumorous part shared common characteristics in the irregular growth ring boundary, misshapen and shorter individual fibers and vessel elements, and large ray widths and heights. The springwood pores were smaller in diameter in the tumor wood, and the larger radial and smaller tangential diameters of summerwood solitary pores and individual pores consisting of pore multiples in proportion of the 2nd growth ring formed after the barrier zone were transformed into near-isodiametric in the tumor wood, the 3rd growth ring, in the tumorous part. Only in proportion of the 2nd growth ring formed after the barrier zone were transformed into near-isodiametric in the tumor wood, the 3rd growth ring, in the tumorous part, ray densities greatly increased. And the massive tumor wood was caused not by cell size but by cell number because the radial and tangential diameters of fibers in the tumor wood, the 3rd growth ring, in the tumorous part were not sufficiently different from those in the same aged growth rings of the directly and 40cm above and below the tumorous part.

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Clinical and radiographic evaluation of $Neoplan^{(R)}$ implant with a sandblasted and acid-etched surface and external connection (SLA 표면 처리 및 외측 연결형의 국산 임플랜트에 대한 임상적, 방사선학적 평가)

  • An, Hee-Suk;Moon, Hong-Suk;Shim, Jun-Sung;Cho, Kyu-Sung;Lee, Keun-Woo
    • The Journal of Korean Academy of Prosthodontics
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    • v.46 no.2
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    • pp.125-136
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    • 2008
  • Statement of problem: Since the concept of osseointegration in dental implants was introduced by $Br{{\aa}}nemark$ et al, high long-term success rates have been achieved. Though the use of dental implants have increased dramatically, there are few studies on domestic implants with clinical and objective long-term data. Purpose: The aim of this retrospective study was to provide long-term data on the $Neoplan^{(R)}$ implant, which features a sandblasted and acid-etched surface and external connection. Material and methods: 96 $Neoplan^{(R)}$ implants placed in 25 patients in Yonsei University Hospital were examined to determine the effect of the factors on marginal bone loss, through clinical and radiographic results during 18 to 57 month period. Results: 1. Out of a total of 96 implants placed in 25 patients, two fixtures were lost, resulting in 97.9% of cumulative survival rate. 2. Throughout the study period, the survival rates were 96.8% in the maxilla and 98.5% in the mandible. The survival rates were 97.6% in the posterior regions and 100% in the anterior regions. 3. The mean bone loss for the first year after prosthesis placement and the mean annual bone loss after the first year for men were significantly higher than that of women (P<0.05). 4. The group of partial edentulism with no posterior teeth distal to the implant prosthesis showed significantly more bone loss compared to the group of partial edentulism with presence of posterior teeth distal to the implant prosthesis in terms of mean bone loss for the first year and after the first year (P<0.05). 5. The mean annual bone loss after the first year was more pronounced in posterior regions compared to anterior regions (P<0.05). 6. No significant difference in marginal bone loss was found in the following factors: jaws, type of prostheses, type of opposing dentition, and submerged /non-submerged implants (P<0.05). Conclusion: On the basis of these results, the factors influencing marginal bone loss were gender, type of edentulism, and location in the arch, while the factors such as arch, type of prostheses, type of opposing dentition, submerged / non- submerged implants had no significant effect on bone loss. In the present study, the cumulative survival rate of the $Neoplan^{(R)}$ implant with a sandblasted and acid-etched surface was 97.9% up to a maximum 57-month period. Further long-term investigations for this type of implant system and evaluation of other various domestic implant systems are needed in future studies.

Studies on Genetic Analysis by the Diallel Crosses in $F_2$ Generation of Cowpea(Vigna sinensis savi.) (동부 Diallel Cross$ F_2$세대의 유전분석에 관한 연구)

  • Kim, J.H.;Ko, M.S.;Chang, K.Y.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.28 no.2
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    • pp.216-226
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    • 1983
  • Genetic studies on the $F_2$ generation of a set of half diallel crosses involving six cowpea varieties were conducted. by the randomized block design with three replications to determine combining ability, gene action and the relationships between parents and their $F_2$ hybrids. The 12 agronomic characters namely, days to flowering, days from flowering to maturity, days to maturity, diameter of stem, length of internode, number of branches per plant, length of pod, number of pods per plant, number of grains per pod, number of grains per plant, 100 grain weight and grain weight per plot were observed, and the $F_2$ generation of this diallel set of crosses was analysed for each character according to the method by Jinks and Hayman. The results obtained are summarized as follows: 1. Vr-Wr graphical analyses; The following seven characters, days to flowering, number of branches per plant, length of pod, number of pods per plant, number of grains per plant, 100 grain weight and grain weight per plot appeared to be partially dominant, and over dominance was found for days from flowering to maturity, days to maturity, length of internode and number of grains per pod. But diameter of stem indicated partial dominance near complete dominance. 2. Estimates of genetic variance components; In the degree of dominance,. eight characters, that is, days to flowering, days from flowering to maturity, days to maturity, length of internode, number of pods per plant, number of grains per pod, number of grains per plant and grain weight per plot were expressed larger than 1. And the characters, days from flowering to maturity, number of branches per plant and number of grains per plant as the degree of mean dominance ($H_1$/D) were found to be negative value over other characters. On the other hand, apprent asymmetry of dominance-recessive allele ($H_2$ /$4H_1$) produced comparatively estimates with lower value on days from flowering to maturity, length of internode, number of branches per plant and number of grains per pod. 3. Analyses of combining ability; Mean square value of GCA(general combining ability) appeared to be more important than those of SCA (specific combining ability) for most characters, and among them, grain weight per plot showed the highest mean square value in GCA and SCA. 4. Effect of combining ability; Variety 178 was expressed as the highest GCA effects in five characters (days to flowering days to maturity, number of pods per plant, number of grains per plant and grain weight per plot). SCA effects were differed from parents, characters and crosses, but crosses between TVu 1857 $\times$ TVu 2885 and TVu 2702 $\times$ J78 were shown to be highly with SCA effects on yield.

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