• Title/Summary/Keyword: Half Life

Search Result 1,829, Processing Time 0.029 seconds

The Expression of Matrix Metalloprotease 20 is Stimulated by Wild Type but not by 4 bp- or 2 bp-Deletion Mutant DLX3

  • Park, Hyun-Jung;Ryoo, Hyun-Mo;Woo, Kyung-Mi;Kim, Gwan-Shik;Baek, Jeong-Hwa
    • International Journal of Oral Biology
    • /
    • v.34 no.1
    • /
    • pp.21-28
    • /
    • 2009
  • Mutations in DLX3 are associated with both autosomal dominant hypoplastic hypomaturation amelogenesis imperfecta (ADHHAI) and tricho-dento-osseous (TDO) syndrome. ADHHAI is caused by a c.561_562delCT (2bp-del DLX3) mutation whereas TDO syndrome is associated with a c.571_574delGGGG (4bp-del DLX3) mutation. However, although the causal relationships between DLX3 and an enamel phenotype have been established, the pathophysiological role of DLX3 mutations in enamel development has not yet been clarified. In our current study, we prepared expression vectors for wild type and deletion mutant DLX3 products (4bp-del DLX3, 2bp-del DLX3) and examined the effects of their overexpression on the expression of the enamel matrix proteins and proteases. Wild type DLX3 enhanced the expression of matrix metalloprotease 20 (MMP20) mRNA and protein in murine ameloblast-like cells. However, neither a 4bp-del nor 2bp-del DLX3 increased MMP20 expression. Wild type DLX3, but not the above DLX3 mutants, also increased the activity of reporters containing 1.5 kb or 0.5 kb of the MMP20 promoter. An examination of protein stability showed that the half-life of wild type DLX3 protein was less than 12 h whilst that of both deletion mutants was longer than 24 h. Endogenous Dlx3 was also found to be continuously expressed during ameloblast differentiation. Since inactivating mutations in the gene encoding MMP20 are associated with amelogenesis imperfecta, the inability of 4bp-del or 2bp-del DLX3 to induce MMP20 expression suggests a possible involvement of such mutations in the enamel phenotype associated with TDO syndrome or ADHHAI.

Estimation of Critical Chloride Content for Corrosion of Reinforcing Steel in Concrete by Field Exposure Experiment (현장 폭로실험에 의한 콘크리트 중 철근의 부식 임계 염화물량 평가)

  • Yu, Kyung-Geun;Bae, Su-Ho;Park, Jae-Im;Lee, Kwang-Myong;Kim, Jee-Sang
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2008.04a
    • /
    • pp.585-588
    • /
    • 2008
  • To predict the service life of reinforced concrete structures exposed to chloride environment, quantitative measures of material properties such as the critical chloride content for corrosion in concrete and the diffusion coefficient of chloride ions of concrete and the surface chloride content of the concrete are essential. However, it should be noted that they are influenced by several factors such as concrete mix proportions, cement type, and environmental conditions, etc. Thus, the purpose of this research is to estimate more actually the critical chloride content for corrosion of the reinforcing steel in concrete by field exposure experiment. For this purpose, the prism concrete test specimens were made for water-cement(W/C) ratios of 31%, 42%, 50%, and 70%, and then the field exposure experiment for them were conducted at Youngduk of the east coast for about 3 years. During the test, corrosion monitoring by half cell potential method was carried out to detect the time to initiation of corrosion for test specimens and its chloride content was evaluated by breaking the concrete test specimens when corrosion of the reinforcing steel in concrete was perceived. It was observed from the test results that the critical chloride content for corrosion of reinforcing steel in concrete would be dependent on W/C ratio and almost irrespective of concrete cover.

  • PDF

A Study on a Habitat View of Korean Traditional Villages - in the case of Chung Jae Kwon Bul family - (조선시대 전통마을의 서식관에 관한 연구 - 충재 권벌의 종가를 중심으로 -)

  • 최기수
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.26 no.4
    • /
    • pp.82-94
    • /
    • 1999
  • According to Korean's geographical features of Taek Li Ji, the best location for human settlements is on the vicinity of a stream among a stream, an river and a sea, and not far from a ridge. The researcher chose one of best village which is called Yougokmaeul in Bonghwa-Gun, Kyungsang-Do. This village was created a gathering village with the same surname, can be translated as a hen and the front mountain can be seen as a rooster in the view of the shape of geographical features. As it were, the shape of this village and the cultivated land seems to be an egg inside a nest of a parent's chicken in the respect of the analogy of the theory of P'ungsuchiri which is known as Feng Shui in China and geomancy in the western world, and to effect the defensive psychology of the living environment in the terrain inland. This village is the studying place, Suckchunjungsa as the lecturing and studying place for their following students within the Chunghadonchun, the studying Yougok village, and even the ritual place performing ancestral sacrifices and the first incoming ancestor's graves in the same geographical system. The house site of the first incoming resident is surrounded the countian and is located in the front of Backsulryount which is the main mountain through Moonsu-san in the branch mountain of Korean's mountain system. Backsulryoung which is to be seen as the white peak, is symbolized the head of a hen which is to relate to a mysterious turtle in the view of P'ungsuchiri. And the pavilion which is called Chungamjung is sited on the rock of a shape of turtle which is symbolized to live longer. In the section of the mountain and water, Lee Jung Hwan mentioned a living place near the mountain stream is the best residential area and a landscape which is composed by a stream between mountains make a pleasure spirit and a bright feeling and make a refined person. If one can reach in the graceful mountain make a pleasure split and a bright feeling and make a refined person. If one can reach in the graceful mountain half day away, this kind of place must be a best living residential area to live. But this village was structured all in one place. And one of the ideas tangibly reflected in traditional Korean society's view of life and nature is the seclusion based on the Taoism. This kind of a dreamy thoughts make a dream to keep the paradise in our ancestors' mind. This kind of utopia is Chunghadonchun which is structured 5 aspects from the utopian gate near the Samgaesuewon to the village. These 5aspects is expressed by some Confucian thoughts as a small cosmos individually. On the third aspects which is the center among these aspects, the Suckchunjungsa which was made a seclusion place to devoting himself to his studies with refined tastes. The word of Jiju-am, Gangpung-dae, Jaewol-dae and Biryoung-pock are all expressed to cultivate one's moral character and to seek the truth by the Confucius'theory through the nature.

  • PDF

The Development of a Standardized Work Process for Planning of Plant Project - Focus on Excavating and Investing Participation Plan - (플랜트 프로젝트 사업기획단계 표준 업무 프로세스 개발 - 사업발굴 및 사업참여 결정을 중심으로 -)

  • Lee, Do-yun;Choi, Chang-Hoon;Won, Seo-kyung;Cho, Moon-Young;Han, Choong-Hee;Lee, Junbok
    • Korean Journal of Construction Engineering and Management
    • /
    • v.17 no.4
    • /
    • pp.3-11
    • /
    • 2016
  • Recently, overseas plant orders of domestic enterprises are steadily increased, and the amount of orders in the first half of 2014 were 93% increased compared to the previous year. In addition, now which is the third quarter of 2015, overseas plant orders are already over 249.8 billion dollars so the interests of plant industry research has been increased. In the life cycle of the plant project, CM before the construction stage is to complement the uncertainties that are inherent in the early stages of the project, and from the viewpoint of supporting the rational decision-making, the importance of its role is on the rise. Among them, excavating and investing participation plan in the planning stage is an important work that has a large impact force to influence the success and failure of future project. However, the work has become a problem with frequent consultations due to decision-making, continuous modification, and inefficient repetitive tasks. Therefore, it is needed that work process should be changed to effectively accommodate. The purpose of this paper is to derive the major work items for excavating and investing participation plan in the planning stage of the plant project, and establish a standardized work process through the Delphi analysis. The result of this study is expected to be utilized for EPC companies in ensuring the technical competitiveness in planning on overseas markets, and improve the efficiency of work.

The Biological Effectiveness and Persistence of Malathion Residues on the Polished Rice under the Natural Grain Storage Conditions (백미에 처리한 Malathion 잔류효력과 지속성에 관하여(자연적 곡물저장 조건하에서))

  • 최승윤
    • Korean journal of applied entomology
    • /
    • v.2
    • /
    • pp.22-26
    • /
    • 1963
  • 1) This experiment was planned to determine the biological effectiveness and persistence of malathion residues on the polished rice under the natural storage conditions in Korea from June to September in 1963). 2) Whole kernel rice was treated with malathion as a spray. The test insects(21 days old were exposed) for a period of 8 days at given day intervals, 3) The biological effcetiveness and persistence of malathirm residues on the polished rice was determined as the mortality of the rice weevils, Sithophilus oryzas L. 4) It was observed from Table 1 and Fig. 1 that 100 per cent mortality was resulted in at 3 days from treatment in all dosages used in this experiment. At :1':days after treatment, the dosages of 16ppm and 8ppm gave still 100 per cent mortality, but the dosages of 4 ppm and 2 ppm resulted in $85.8\pm3.70\;and\; 43.3\pm10.77 per cent mortalities, respectively. After 32 days from the treatment,the mortalities in all dosages used did not show any 100 per cent mortality, At. 107 days after treatment, there was no any difference in the mortality of weevils inall dosages used. 5). It was observed from Fig. 1 and Table 2 that the half-life values of malathion residues on the polished rice was 33 days at 2 ppn!, 54 days at 4 ppm, 73 days at 8 ppm, and 93days at 16ppm, respectively. 6). To get a satisfactory control of the rice weevile with the malathion-residues for more than 5 months under the natural storage conditions, it may be necessary to use higher dosages than those used in this experiment.

  • PDF

THE ROLE OF REACTIVE OXYGEN SPECIES ON UVA-INDUCED AGING OF DERMAL COLLAGEN (진피 콜라겐의 노화에 대한 활성산소와 자외선의 영향)

  • Kang, S.J.;Hong, S.D.;Cho, W.G.;Chae, Q.
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.18 no.1
    • /
    • pp.64-80
    • /
    • 1992
  • Considerable interest has been generated in age-related non-enzymatic glycosylation and crosslinking of collagen in view of its extracellular nature, and its long biological half-life. The effects of UVA, which penetrates deep in dermis, and reactive oxygen species (ROS) on age- related changes of dermal collagen were studied. The amount of nonenzymatic glycosylation, fragmentation, and crosslinking of collagen were monitored from the mixtures of Type I collagen from calf skin and glucose, irradiated by UVA, with or without scavengers of ROS. At both high and low glucose dosages, non-enzymatic glycosylation was not affected by UVA irradiation. At high glucose dosage, however, glycosylation was reduced by the scavengers of superoxide radical and singlet oxygen, bolt not by hydroxyl radical scavengers. Fragmentation was increased by UVA and decreased by all ROS scavengers. Crosslinking was also enhanced by UVA, and effectively blocked crosslinking. Superoxide radical and singlet oxygen, which were produced by autoxidation of glucose independently to UVA, may encounter the initial phase of glycation. ROS generated from Amadory compounds by UVA enhanced fragmentation and crosslinking Hydroxyl radical was thought to be a major ROS affecting crosslinking. These results suggest that UVA and ROS are able to enhance age-related structural changes of collagen, as affecting many other tissue and cellular components.

  • PDF

In vitro and in vivo Evaluations of LB 10517, a Novel Parenteral Broad-Spectrum Cephalosporin

  • Song, Hye-Kyong;Nishino, Takeshi;Seo, Mi-Kyeong;Kim, Mu-Yong;Lee, Yong-Hee;Kim, In-Chull;Kwak, Jin-Hwan
    • Archives of Pharmacal Research
    • /
    • v.19 no.1
    • /
    • pp.46-51
    • /
    • 1996
  • The in vitro activity of LB 10517, a new catechol-substituted cephalosporin, was compared with those of E-1077, cefpirome and ceftazidime 1034 clinical isolates collected in Japan. LB10517 showed a broad-spectrum antibacterial activity against a wide range of grampositive and gram-negative bacteria including non-glucose fermenting rods, Pseudomonas aeruginosa. Against the methicillin-susceptible strains of Staphylococcus aureus (MSSA) and Strptoccus pyogenes, the $MIC_{90}$ values of LB10517 which required to inhibit 90% of the strains wre $3.13\mug/ml\; and\; 0.1\mug/ml$, respectively. It was as active as E-1077 but more active than cefpirome and ceftazidime. Methicillin-resistant strains of S.aureus (MRSA) and Enterococcus spp. were highly resistant to all the test compunds. LB10517 was highly active against most members of the family Enterobacteriaceae, 90% of which were inhibited at a concentration of less than $0.78\mug/ml$, except for Enterobacter cloacae ($1.56\mug/ml$) and Serratia marcescens ($3.13\mug/ml$)Its activity was comparable to those of E-1077 and cefpirome but it was greater than that of ceftazidime. Against Pseudomonas aeruginosa, LB10517 showed the most potent antibacterial activity among the compounds tested. Ninety percent of P. aeruginosa isolates were susceptible at the concentration of $0.39\mug/ml$. Its activity was 32-to 128 fold higher than those of E-1077, cefpirome and ceftazidime. Against imipenem- or ofloxacin-resistant P. aeruginosa, LB10517 with $MIC_{90}\; of\; 6.25 \\mug/ml\; and\; 3.13\mug/ml$, respectively, showed 16-fold more potent activity than the other test compounds. LB10517 showed a relatively high plasma level and long plasma elimination half-life in rats $(t_{1/2}(\beta,\; 52 min)\; and\; dogs\; (t_{1/2}(\beta),\; 103 min)$.

  • PDF

Pharmacokinetics of Recombinant Human Epidermal Growth Factor (DWP401) after Repeated Subcutaneous Administration to Rats (흰쥐에 재조합 인간 상피세포 성장인자(DWP401)를 연용피하투여했을 때 약물체내동태)

  • Nam, Gwon-Ho;Jo, Jae-Yeol;Jeong, Ju-Yeong;Jang, U-Ik;Gang, Jin-Seok;Yu, Eun-Suk;Park, Seung-Guk;Yu, Yeong-Hyo;Park, Myeong-Hwan;Sim, Chang-Gu
    • YAKHAK HOEJI
    • /
    • v.40 no.5
    • /
    • pp.491-500
    • /
    • 1996
  • The organ distribution and pharmacokinetics of DWP401, a recombinant human epidermal growth factor (rhEGF), were compared after single and repeated subcutaneous administration ( 50${\mu}$/kg, 10${\mu}g$Ci/kg of $^{125}I$-DWP401, twice a day for 7 consecutive days) to rats. The pharmacokinetic parameters such as AUC and terminal half-life were similar between two different administration. During repeated administration, the plasma concentration of DWP401 seemed to be constant when the plasma was collected at 15 min after each dosing. The TCA-precipitated radioactivities in thyroid, liver, kidney, and stomach were higher than those of other organs studied after both single and repeated administration. The TCA-precipitated radioactivities after repeated administration in several organs, such as thyroid, stomach, prostate, adrenal, eye ball, and testis were higher than those after single administration. But, according to the observations using gel filtration chromatography and antibody binding assay, the radioactivities in thyroid and stomach were not primarily due to the intact DWP401 or its metabolites but due to the $^{125}I$-thyroxine binding protein. In conclusion, it can be suggested that DWP401 is metabolized to each amino acid or small polypeptides, and there was no significant changes in pharmacokinetics or any indications for accumulation of DWP401 in rat plasma and organs after repeated treatment.

  • PDF

NEW DRUG THERAPY IN CHILD AND ADOLESCENT PSYCHIATRY-NEW LONG-ACTING PSYCHOSTIMULANTS (소아청소년 정신과 영역에서의 새로운 약물치료:새로운 장기작용형 중추신경자극제)

  • Choi, Sung-Ku
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
    • /
    • v.14 no.1
    • /
    • pp.3-11
    • /
    • 2003
  • Attention-deficit/Hyperactivity disorder(ADHD) is the most common psychiatric disorder of childhood and among the most prevalent chronic health conditions affecting school-aged children. Children with ADHD experience significant functional problems, such as school difficulties, academic underachievement, troublesome interpersonal relationships with family members and peers, and low self-esteem. The most widely used pharmacological treatments for ADHD are psychostimulants, such as methylphenidate and amphetamine salts. These medications provide clinical efficacy by increasing the availability of catecholamines, primarily dopamine, in the frontal lobe of the brain. immediate-release(IR) formulations of sychostimulants were among the most effective psychotrophic medications in the psychopharmacological treatment. However, there are some limitations of IR formulations:the short half-life and duration of efficacy, which result in the need for multiple daily dosing and the poor compliance. These limitations have led to the development of once-daily, extended-release(ER) formulations of methylphenidate and amphetamine salts. However, these ER formulations may not be as immediately helpful to ADHD children due to delayed onset of action and the acute tolerance which is the failure to sustain the efficacy with the same concentration of drug as the initial stage of medication. OROS-methylphenidate(Concerta$^{\circledR}$) given once a day produces an ascending-pattern plasma drug level generated by the osmotically released, timed drug-delivery system. These new formulations of the psychostimulants have been shown to be a useful alternative to old stimulant medications through the evidence by the clinical trials.

  • PDF

Practices and Needs of Health Promotion Program among Workers in A Petrochemical Industry Complex (석유화학단지 근로자들의 건강행위 실천 정도와 건강증진 요구도)

  • Kim, Mi-Ae;Chun, Jin-Ho
    • Korean Journal of Occupational Health Nursing
    • /
    • v.13 no.2
    • /
    • pp.104-117
    • /
    • 2004
  • Objectives: To propose the basic data for the development of the optimum health promotion program (HPP) for the workers in a petrochemical industry complex. Methods: The subjects were 553 workers who worked at the six plants in a petrochemical industry complex. From February to March 2003, questionnaire survey was conducted by the nurses with occupational health specialty about the life styles, interests, self-cognitions, practices of health behavior, subjective symptoms thought to be related the working environments, burden to the own health, needs and intentions to participation of the HPP. Data analysis was done using SPSS program (ver 10.0) with ${\alpha}=0.05$ of statistical significance. Results: The mean age and tenure of the subjects were 39.7 years and 14.2 years, respectively, and proportion of smokers was around 50%. Two of third (66%) satisfied their own job, and 58% recognized themselves healthy. The most frequent health behavior were exercise (60%) and regular health check (87%) in individual and job based, respectively. About half of them (58%) had at least one of the symptoms thought to be related the working environments, and the most frequent one was odor (21%). These symptoms were more frequent in case of the shorter career. The needs of HPP was relatively higher in exercise (66%), cancer prevention (51%), stress control (47%), and intention to participation was also the highest in exercise (64%). Job satisfaction was higher in case of the higher interests and cognitions to their own health, and thought that the ownership's interest to workers' health be high (p<0.01), but no associations with the subjective symptoms. The mean level of burden to the own health were $14.1{\pm}13.9$ of physical, $11.7{\pm}13.6$ of emotional, $9.1{\pm}10.7$ of behavioral as out of one hundred. They felt the more burden in case of office workers, the lower interests and cognitions to their own health, the lower satisfaction to their job, the frequent drinking group, and complained the subjective symptoms (p<0.05). Abnormal results of the regular health check was higher in the frequent drinking group (p=0.083). Conclusions: For the optimum HPP for the workers in the petrochemical complex, the ownership's interest to workers' health would be enhanced, and the priority would be focused on exercise and drinking habits control.

  • PDF