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Kinetics of Photocatalytic Reactions with Porous Carriers Coated with Nano-$TiO_2$ Particles (나노-$TiO_2$ 입자로 코팅된 다공성 담체의 광촉매 반응에 관한 동력학)

  • Park, Seong-Jun;Rittmann, Bruce E.;Bae, Woo-Keun
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.10
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    • pp.927-932
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    • 2009
  • Toxic and recalcitrant organic pollutants in wastewaters can be effectively treated when advanced oxidation and biodegradation are combined, ideally with intimate coupling, in which both processes occur simultaneously in the same system. One means to achieve intimate coupling is to coat nanoscale $TiO_2$ on the outside of macroporous biofilm carriers. This study investigated the kinetics of photocatalysis with $TiO_2$-coated porous carriers. The carriers were made of polyvinyl alcohol (PVA) and coated with $TiO_2$ using a low-temperature sol-gel process. The $TiO_2$-coated carriers catalyzed the oxidation of methylene blue (MB) effectively under irradiation of UV light. The overall reaction rate with adsorption and photolysis saturated at high MB concentration, and approached the adsorption rate, which was first order for all MB concent rations. This result indicates that adsorbed MB may have slowed photocatalysis by blocking active sites for photocatalysis. The overall kinetics could be described by a quasi-Langmuir model. The estimated maximum specific (per unit mass of $TiO_2$) transformation rate of MB by the $TiO_2$-coated carriers was four times larger than that obtained from slurry-$TiO_2$ reactors. This observation demonstrated that the $TiO_2$ present as a coating on the carriers maintained high efficiency for transforming recalcitrant organic matter via photocatalysis. These findings serve as a foundation for advancement of an intimate coupling of photocatalysis to biodegradation.

Caspase-3 Specifically Cleaves $p21^{WAF1/CIP1}$ in the Earlier Stage of Apoptosis in SK-HEP-1 Human Hepatoma Cells

  • Park, Jeong-Ae;Kim, Kyu-Won;Kim, Shin-Il;Lee, Seung-Ki
    • Proceedings of the Ginseng society Conference
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    • 1998.06a
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    • pp.231-243
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    • 1998
  • In the present study, we provide evidence that ginsenoside $Rh_2$ (G-$Rh_2$) as well as staurosporine induces apoptosis of human hepatoma SK-HEP-1 cells by caspase 3-mediated processing of $p21^{WAFI/CIPI}$ in the early stage of apoptosls. Immunoblottings showed that G-$Rh_2$ as well as statrosporine induced the processing of caspase-3 to an active form, pl7. In stable Bcl-2 transfectants however, G-$Rh_2$ induced DNA fragmentation, while staurosporine did not. In the early stage of apoptosis, $p21^{WAFI/CIPI}$ was detected to undergo proteolytic processing specifically conducted by caspase-3. $p21^{WAFI/CIPI}$ translated in vitro was cleaved into a p14 fragment, when incubated with cell extracts obtained from either G-$Rh_2$- or staurosporine-treated cells. Cleavage was equally inhibited in both cases by adding Ac-DEVD-cho, a specific caspase-3 inhibitor, but not by Ac-YVkD-cho, a specific caspase-l inhibitor. Similarly, $p21^{WAFI/CIPI}$ was efficiently leaved by recombinant caspase-3 overexpressed in E. coli. Moreover, the endogenous $p21^{WAFI/CIPI}$ of untreated-cell extracts was also cleaved by recombinant caspase-3. Mutation analysis allowed identification of two caspase-3 cleavage sites, $DHVD^{112}$/L and $SMTD^{149}$/F, which are located within, or near the interaction domains for cyclins, Cdks, and PCNA. Taken together, these results show that G-$Rh_2$ as well as staurosporine increases caspase-3 activity, which in turn directly cleaves $p21^{WAFI/CIPI}$ resulting in elevation of Cdk kinase activity in the early stages of apoptosis. We propose that proteolytic cleavage of $p21^{WAFI/CIPI}$ is a functionally relevant event that allows unleashing the cyclin/Cdk activity from the inhibitor seen in the earlier stage of apoptosis, the event of which may be associated with the triggering mechanism for the execution of apoptosis.

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On the Kinds of Ants(Hymenoptera: Formicidae) and Vertical Distribution in Jiri Mountain (지리산지역(智異山地域)의 개미의 종류(種類)와 수직분포(垂直分布))

  • Kim, Chang-Hyo;CHOI, BYEONG-MOON
    • Korean journal of applied entomology
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    • v.26 no.3 s.72
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    • pp.123-132
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    • 1987
  • Vertical distribution of ants were studied in Jiri mountain by collecting 15 times at 42 sites for 3 years since 1984. 31 species of 16 genera in 3 subfamilies were collected during the survey. The following 6 species, i.e., Formica japonica, F. lemani, Lasius niger, L. alienus, Pheidole fervida and Myrmica ruginodis were dorminant one, but 9 species such as Leptothorax congruus, Pheidole nodus, Aphanogaster japonica, Jollenhovia emeryi, Camponotus tokioensis, Polyrhachis lamellidens, Phagiolepsis mandjurica, myrmica yessensis and M. sulcinodis were rare species. The ant of Jiri mountain consisted of 16 species in Formicinae, 13 species in Myrmicinae and 2 species in Ponerinae. Ponerinae was distbriuted as far as 1,800m, but Myrmicinae and Formicinae to 1,915m. Only 8 species-Myrmica ruginosis, Myrmica sp., M. yessensis, M. sulcinodis, Leptothorax acevorum, Formica japonica, F. lemani and Camponotus japonicus-were collected at the submit of Jiri mountain, Cheonwangbong. The vertical distribution of C. atrox was ranged from 800m to 1,800m.

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DISTRIBUTION CHARACTERISTICS OF NUTRIENTS IN CHINESE BOHAI SEA

  • Li, Zhengyan;Gao, Huiwang;Bai, Jie;Shi, Jinhui
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2001.11a
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    • pp.19-29
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    • 2001
  • Nutrients are key environmental factors in marine ecosystem. They limit algal growth when at low concentrations and cause algal bloom when at high contents. They also control the growth and succession of many other biota including bacteria and zooplankton, either directly or indirectly. Nutrient contents therefore affect both the structure and functions of marine ecosystem. To study the contents and distribution of nutrients in Chinese Bohai Sea, two cruise surveys were undertaken in August 2000 (summer) and January 2001 (winter), respectively. A total of 595 water samples were collected from 91 sites. After collection the samples were transported to the laboratory and five nutrients, i.e., nitrate, nitrite, ammonia, phosphate and silicate, were analyzed. The results showed that tile average concentration of total inorganic nitrogen (TIN) in Bohai Sea in winter (6.5293.717 ${\mu}$mol$.$l$\^$-1/) was significantly higher than that in summer (3.717 ${\mu}$mol$.$l$\^$-1/). The phosphorus concentration in winter (0.660 ${\mu}$mol$.$l$\^$-1/) was also significantly higher than that in summer (0.329 ${\mu}$mol$.$l$\^$-1/). Mean silicate concentration in winter (7.858 ${\mu}$mol$.$l$\^$-1/) was not significantly different from that in summer (7.200 ${\mu}$mol$.$l$\^$-1/). Nutrients also varied considerable among different areas within Bohai Sea. TIN concentration in Laizhou Bay (4.444 ${\mu}$mol$.$l$\^$-1/), for example, was significantly higher than those in Bohai Bay (2.270 ${\mu}$mol$.$l$\^$-1/) and Bohai Straight (2.431 ${\mu}$mol$.$l$\^$-1/), which probably reflects tile discharge of large amounts of nitrogen into Laizhou Bay via Yellow River. The nutrients also showed vertical distribution pattern. In summer, nutrients in bottom layer were generally higher than those in surface and medium layers. In winter, however. nutrients in different layers were not significantly different Compared with historic data, TIN contents increased continuously since early 1980s, phosphorus arid silicone contents, nevertheless, fell down to some degree. Based on atomic ratios of different nutrients, nitrogen is still the main limiting factor for algal growth in Bohai Sea.

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The Effect of composite Graft of allogenic DFDB and Calcium Sulfate with and without Calcium Sulfate barrier in Periodontal 1 wall intrabony defects in Dogs (성견 1면 골내낭에서 탈회 냉동 건조골과 calcium sulfate 혼합 이식 및 calcium sulfate 차단막 사용이 치주조직 치유에 미치는 영향)

  • Moon, Hee-Il;Cho, Kyoo-Sung;Chai, Jung-Kiu;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
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    • v.28 no.2
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    • pp.219-237
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    • 1998
  • Numerous bone graft materials have been used in Periodontics, in an attempt to reach the main goal of periodontal therapy, i.e. the regeneration of periodontal tissue lost due to destructive periodontal diseases. The present study investigates the effect of composite graft of DFDB and Calcium sulfate with and without Calcium sulfate barrier in Periodontal 1-wall intrabony defects in dogs. Following the initiation of general anesthesia by I.V. administration of 40mg/Kg of Pentobabital, second premolar was extracted and full thickness flap elevated. The crown portion of premolars was removed. Exposed root canals were sealed with Caviton and covered completely with flap. After the healing period of 8 weeks, the surgical sites were re-opened and 1-wall intrabony defects were created, and treated with flap operation alone(control group), with composit graft of 80% DFDB and 20% Calcium sulfate(Experimental group 1), with composite graft of DFDB and calcium sulfate with calcium sulfate membrane( Experimental group 2). Healing response was histologically observed after 8 weeks and the results were as follows : 1. New bone formation was 70 % in the control group, 93 % in the Experimental group I, 89 % in the Experimental group II. There was a no differences between Experimental groups. 2. New cementum formation was not significantly different between control and two Experimental groups. 3. The length of connective tissue adhesion was 30 % in the control, 7% in the Experimental group I and 11 % in the Experimental group II. 4. After 8weeks, calcium sulfate was completely resorbed, while DFDB particle remained. These results suggest that the use of composite graft of allogenic DFDB and Calcium sulfate with and without Calcium sulfate barrier in periodontal 1 wall intrabony defects have little effect on connective tissue adhesion, but has beneficial effect on new alveolar bone and new cementum formation, and prevent downgrowth of epithelium and connective tissue effectively.

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A Study on Characteristic of Forest Vegetation and Site in Mt. Odae(I) -Classification of Plant Community in Tongdaesan- (오대산(五臺山)의 산림식생(山林植生)과 입지특성(立地特性)에 관한 연구(硏究)(I) - 동대산지역(東臺山地域)의 식물군락분류(植物群落分類) -)

  • Lee, Sun
    • Journal of Korean Society of Forest Science
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    • v.89 no.2
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    • pp.173-184
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    • 2000
  • The aim of this study was to characterize the forest vegetation and site of Tongdaesan(Odaesan National Park) for ecological forest management. The deciduous forests of Tongdaesan are the result of cool, temperate climate. Direction and slope morphology contribute to differences in species composition and vegetaion structure. Based on the BRAUN-BLANQUET-approach, 242 releves were recorded and subsequently classified. The vegetation could be divided into two forest community groups, seven forest communities, and several groups. South exposed, dry slopes were covered with forests of the Quercus mongolica-Acer pseudo-sieboldianum community group. Differential species included grasses and sedges, e.g., Calamagrostis langsdorfii, Carex humilis and C. lanceolata. Quercus mongolica-Acer pseudo-sieboldianum community group could be subdivided into Rhododendron mucronulatum var. ciliatum community, Lespedeza${\times}$tomentella community, Carex humilis-Maackia amurensis community, Quercus mongolica-Acer pseudosieboldianum typical community and Pimpinella brachycarpa community. Carex humilis-Maackia amurensis community was divided into Galium kinuta subcommunity and typical subcommunity. Pimpinella brachycarpa community was divided into Vicia venosa var. cuspidata subcommunity and typical subcommunity. On north exposed, more humid and moist sites, forests of the Dryopteris crassirhizoma-Cornus controversa community group were found. This group was subdivided into Acer tschonoskii var. rubripes-Acer tegmentosum community and Deutzia glabrata-Ulmus laciniata community. Deutzia glabrata-Ulmus laciniata community was divided into Acer tegmentosum subcommunity, Saxifraga punctata subcommunity and typical subcommunity.

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Syntaxonomy and Syngeography of Korean Red Pine (Pinus densiflora) Forests in Korea (한국 소나무림의 군락분류와 군락지리)

  • Chun, Young-Moon;Lee, Ho-Joon;Hayashi, Ichiroku
    • Korean Journal of Environment and Ecology
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    • v.21 no.3
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    • pp.257-277
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    • 2007
  • We carried out a phytosociological study on pine forests in Korea with the method of Zurich-Montpellier School. We collected the data of 252 $relev{\acute{e}}s$ from 45 sites in the pine forests throughout the Korean Peninsula and its attached islands. The vegetation of the pine forests was classified into one association, three communities and seven subcommunities as follows: A: Quercus mongolica-Pinus densiflora community, A-1: Typical subcommunity, A-2: Vaccinium korean urn subcommunity, A-3 : Rhododendron micranthum subcommunity, B: Quercus serrata-Pinus densiflora community, B-1: Typical subcommunity, B-2: Juniperus rigida subcommunity, B-3: Styrax japonica subcommunity, B-4: Eurya japonica subcommunity, C: Saso-Pinetum densiflorae Yim et al. 1990, and D: Castanopsis cuspidata var. sieboldii-Pinus densiflora community. The former three communities were integrated into the Lindero-Quercion mongolicae Kim 1990 em. 1992. The Castanopsis cuspidata var. sieboldii-Pinus densiflora community remained to be studied in future to determine the association. The communities of Quercus mongolica-Pinus densiflora community was distributed throughout the montane zone in central-northern part of the Korean Peninsula. Quercus serrata-Pinus densiflora community occupied widely in the sub-montane and hilly areas in central and Southern Korean Peninsula. The association of Saso-Pinetum densiflorae was found in Cheju Island. Castanopsis cuspidata var. sieboldii-Pinus densiflora community were distributed in the warm-temperate zone including islands off the south-west coast of the Peninsula.

Social Factors Affecting Internet Searches on Cyber Bullying in Korea and America Using Social Big Data and Google Search Trends (소셜 빅데이터와 Google 검색트렌드를 활용한 한국과 미국의 사이버불링 검색에 영향을 미치는 요인 분석)

  • Song, Tae-Min;Song, Juyoung;Cheon, Mi-Kyung
    • The Journal of Bigdata
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    • v.1 no.1
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    • pp.67-75
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    • 2016
  • The study analyzed big data extracted from Google and social media to identify factors related to searches on cyber bullying in Korea and America. Korea's cyber bullying analysis was conducted social big data collected from online news sites, blogs, $caf{\acute{e}}s$, social network services and message for between January 1, 2011 and March 31, 2013. Google search trends for the search words of stress, exercise, drinking, and cyber bullying were obtained for January 1, 2004 and December 22, 2013. The main results of this study were as follows: first, the significant factors stress were cyber bullying that Korea more than America. Secondly, a positive relationship was found between stress and drinking, exercise and cyber bullying both Korea and America. Thirdly, significant differences were found all path both Korea and America. The study shows that both adults and teenagers are influenced in Korea. We need to develop online application that if cyber bullying behavior was predicted can intervene in real time because these actual cyber bullying-related exposure to psychological and behavioral characteristic.

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Conservation Status of Rare and Endangered Plant Species in T$\v{o}$kyusan National Park (덕유산 국립공원내 회귀 및 멸종위기식물의 보전실태)

  • Yim, Kyong-Bin;Kim, Yong-Shik;Chun, Seung-Hoon;Kim, Sun-Hee;Kim, Whi
    • Korean Journal of Environment and Ecology
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    • v.7 no.2
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    • pp.112-117
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    • 1994
  • The present conservation status on the rare and endangered plants in Tokyusan National Park were surveyed and re-evaluated by the new criteria which prepared by I.U.C.N. The species such as Lonicera vidalii, Clematis chiisanensis, Cypripedium macranthum and Allium taquetii were grouped as Critical, Eranthis stellata, Abies koreana, Taxus cuspidata, Tricyrtis dilatata, Paeonia japonaca, Stewartia koreana, Rhododendron tschnoskii, Buplerum euphorbioides, Lilium cernum and Oreorchis patens were grouped as Endangered, Adonis amurenis and Disporum ovale were grouped as Vulnerable. The above mentioned species were mainly located at the vicinity of mountain trails and projected developing sites. The potentials for the habitat destructions, mainly, due to human activities are expected to be serious in the future unless the proper management plans prepared for the specific plants and the specific habitats.

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Synthesis, Characterization and ESR Studies of New Copper(II) Complexes of Vicinal Oxime Ligands (Vicinal Oxime 리간드의 새로운 구리(II) 착물에 대한 합성, 특성 및 ESR 연구)

  • El-Tabl, Abdou S.;Shakdofa, Mohamad M.E.;El-Seidy, Ahmed M.A.
    • Journal of the Korean Chemical Society
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    • v.55 no.4
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    • pp.603-611
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    • 2011
  • Ethoxylacetyl oxime ligands [HL, (1) and $H_2L^1$, (3)] react with copper(II) acetate monohydrate yield octahedral and square planar complexes, respectively. The complexes have been postulated due to elemental analyses, IR, UVVis. spectra, magnetic susceptibility, conductivity and ESR spectra. Molar conductance of the complexes in DMF indicates a non-ionic character. The ESR spectra of [$(L)_2Cu(H_2O)_2$], (2) complex at room temperature and 77K are characteristic of an axial symmetry ($d_{x2-y2}$) with covalent bond character and have a large line width typical of dipolar interactions. However, [$(L^1)Cu$], (4) complex in the solid state showed spectra of marked broadening and loss of hyperfine splitting confirming spinexchange interactions between the copper(II) sites. The spectrum of the doped copper(II) complex at room temperature showed super-hyperfine splitting from coordinated nitrogen atoms and it has an axial type ($d_{x2-y2}$) with covalent bond character and an essentially square-planar arrangement around the copper(II) ion. The spectrum of [$(L^1)Cu$], (4) in frozen methanol at 77K was characteristic of the triplet state of a dimer species and the distance found between the two copper(II) centers was calculated and is equal to 4.8 ${\AA}$.