• 제목/요약/키워드: Chemical regulation

검색결과 527건 처리시간 0.024초

Regulation of Stereoselectivity and Reactivity in the Inter- and Intramolecular Allylic Transfer Reactions

  • Yu, Chan-Mo;Youn, Jin-soup;Jung, Hee-Keum
    • Bulletin of the Korean Chemical Society
    • /
    • 제27권4호
    • /
    • pp.463-472
    • /
    • 2006
  • The preparation of enatiomerically enriched homoallylic alcohols through asymmetric addition of chiral allylic transfer reagents and allylating reagents with chiral catalysts to the carbonyl functionalities represents an important chemical transformation. Excellent progress has been made over past decade in the development and application of catalytic asymmetric allylic transfer reactions. In this account, our efforts for the various intermolecular allylic transfer reactions such as allylation, propargylation, allenylation, and dienylation utilizing accelerating strategy and sequential allylic transfer reactions to achieve multiple stereoselection mainly using transition metal catalysts are described.

The effects of work environment monitoring organization's analysts' equipment and chemical substance incident response to the safety management awareness

  • Park, Hyun-A;Choi, Seo-Yeon;Rie, Dong-Ho
    • 한국컴퓨터정보학회논문지
    • /
    • 제22권5호
    • /
    • pp.97-103
    • /
    • 2017
  • In this paper, we propose a method to investigate the safety consciousness of a analyst incident response. This study conducted a statistical survey on 154 analysts who hired as expert in environment monitoring organizations in South Korea. The results of the analyses showed that respondents had good awareness on the equipment incident response and complied with laboratory safety regulations very well. Secondly, respondents were aware of the importance in the order of equipment incident response, an analytical laboratory incident response, and the cause of a chemical substance associated incident in an analytical laboratory in regarding the regulation compliance for creating a safe laboratory environment and the securement of laboratory safety. Therefore, (it was identified that) it would be necessary to create a safe environment and integrate a safety management system.

한국과 중국의 콘크리트용 화학 혼화제 품질 규정 비교 (Comparison of Quality Standards of Chemical Admixtures for Concrete between Korea and China)

  • 후윈야오;임군수;김종;한민철;한천구
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2023년도 봄 학술논문 발표대회
    • /
    • pp.97-98
    • /
    • 2023
  • In this study, comparison of the quality standard of chemical admixtures between Korea and China is conducted. It is classified into three types of water reducing agents: standard, delayed, and accelerated according to the sensitivity and strength improvement of the sensitivity and strength of the agent. However, Chinese standards classify reducing agents only as standard, high efficiency, and high performance, and do not add AE agents into water reducing agent. On the other hand, that of Korea has a classification regulation for reducing agents added with AE agents.

  • PDF

Emerging role of transient receptor potential (TRP) channels in cancer progression

  • Yang, Dongki;Kim, Jaehong
    • BMB Reports
    • /
    • 제53권3호
    • /
    • pp.125-132
    • /
    • 2020
  • Transient receptor potential (TRP) channels comprise a diverse family of ion channels, the majority of which are calcium permeable and show sophisticated regulatory patterns in response to various environmental cues. Early studies led to the recognition of TRP channels as environmental and chemical sensors. Later studies revealed that TRP channels mediated the regulation of intracellular calcium. Mutations in TRP channel genes result in abnormal regulation of TRP channel function or expression, and interfere with normal spatial and temporal patterns of intracellular local Ca2+ distribution. The resulting dysregulation of multiple downstream effectors, depending on Ca2+ homeostasis, is associated with hallmarks of cancer pathophysiology, including enhanced proliferation, survival and invasion of cancer cells. These findings indicate that TRP channels affect multiple events that control cellular fate and play a key role in cancer progression. This review discusses the accumulating evidence supporting the role of TRP channels in tumorigenesis, with emphasis on prostate cancer.

The hypoxia regulation on CYP4501Al expression

  • Kim, Ji E.;Yhun Y. Sheen
    • 한국응용약물학회:학술대회논문집
    • /
    • 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
    • /
    • pp.140-140
    • /
    • 1998
  • The aim of this study was to find out the effect of hypoxic condition on the regulation of cyplal gene expression. pcyplal-Luc construct was cloned and transfected into Hepa I cells. When Hepa-I cells containing pcyplal-Luc were treated by DFO (desferrioxamine) which is iron-chelating agent, the stimulatory effect of luciferase by TCDD was decreased. This inhibitory effect of desferrioxamine on the luciferase activity was dose dependent and abolished by concomitant treatment with N$\^$G/-nitro-ι-arginine. And when cobalt chloride which is known as a hypoxia inducing chemical was administrated, the stimulatory effect of luciferase by TCDD was also decreased. This inhibitory effect of cobalt chloride on the luciferase activity was dose dependent and abolished by concomitant treatment with N$\^$G/-nitro-ι-arginine. These data showed that hypoxic condition down regulates cyplal gene expression and this might be through nitric oxide action.

  • PDF

산화성고체의 위험성평가에 관한 연구 (A Study on the Assessment of Hazardous Properties of the Oxidizing Solids)

  • 이봉우;박철우;송학
    • 한국화재소방학회논문지
    • /
    • 제23권5호
    • /
    • pp.9-16
    • /
    • 2009
  • 최근 급속히 발전하고 있는 과학기술과 산업발달에 따라 화학물질, 위험물의 사용, 저장 및 운송물이 날로 증가하고 있다. 이러한 물질들은 우리의 일상생활과 인류문화 발전에 크게 기여하고 있지만 인화성, 폭발성 등의 잠재위험성을 가지고 있다. 세계 각국은 물질의 분류와 표시가 달라 국제무역에서 많은 사고가 증가하고 있는 실정이다. 이 연구의 목적은 위험물에 대한 국제적인 시험방법을 개발하는 것이며 시험데이터를 기준으로 선택가능방식(Building Block Approach)으로 분류하고자 한다. 국내 위험물안전관리법에서는 위험물을 산화성고체, 가연성고체, 자연발화성물질 및 금수성물질, 인화성액체, 자기반응성물질, 산화성액체로 분류하고 있다. 1차적으로 산화성고체 35종에 대하여 위험물안전관리법에 의한 시험방법, UN시험방법으로 시험한 데이터를 비교하여 이들의 연관성을 도출하고, 국제적으로 분류하여 국내실정에 적합한 산화성고체 시험방법을 제시하였다.

Loss-of-function and Gain-of-function Rice Mutants from Gamma-Ray Mutagenesis

  • Lee, Seon-Woo;Park, Gyung-Ja;Kim, Jin-Cheol;Kim, Heung-Tae;Park, Yong-Ho;Cho, Kwang-Yun
    • The Plant Pathology Journal
    • /
    • 제19권6호
    • /
    • pp.301-304
    • /
    • 2003
  • Gamma-ray irradiation is known to induce various mutations in plants caused by chromosome alterations. This study investigated disease responses of selected gamma-ray induced rice mutants generated from seven Japonica-type rice cultivars against three plant diseases. Among the tested 22 mutants, three gain-of-function mutants and six loss-of-function mutants against rice blast were obtained, as well as three loss-of-function mutants against bacterial leaf blight (BLB). Two of the loss-of-function mutants were susceptible to both rice blast and BLB. Gain-of-function mutation has not been frequently observed in rice plants, thus, the mutants can be used to identify loci of novel genes for the regulation of disease resistant response.

The Regulation of Sugar Metabolism in Huangguan Pears (Pyrus pyrifolia Nakai) with Edible Coatings of Calcium or Pullulan during Cold Storage

  • Kou, Xiaohong;Jiang, Bianling;Zhang, Ying;Wang, Jun;Xue, Zhaohui
    • 원예과학기술지
    • /
    • 제34권6호
    • /
    • pp.898-911
    • /
    • 2016
  • Sugars play many important roles in plant metabolism and directly influence fruit quality. The effects of two edible coatings, 2% calcium chloride and 1% pullulan, on sugar metabolism in postharvest Huangguan pear fruit were investigated during cold storage. The respiration rate, sugar content and composition, sucrose metabolism enzyme activities [acid invertase (AIV), neutral invertase (NI), sucrose synthase (SS), and sucrose phosphate synthase (SPS)] and expression of the AIV gene were analyzed during storage at $0^{\circ}C$ for 210 days. Coating treatments slowed the decrease of sucrose and hexose, the respiration rate, and the activities of AIV, NI, SS and SPS, thus maintaining high total soluble solids (TSS) and titratable acid (TA) contents in the fruit. There were no significant differences in AIV expression or activity between the treated and control groups of fruits. Both of the coatings could inhibit the activities of sucrose-cleaving enzymes, thus slowing the decrease of sugar content and maintaining high fruit quality during cold storage.

The Protein Kinase 2 Inhibitor CX-4945 Induces Autophagy in Human Cancer Cell Lines

  • Kim, Jiyeon;Park, Mikyung;Ryu, Byung Jun;Kim, Seong Hwan
    • Bulletin of the Korean Chemical Society
    • /
    • 제35권10호
    • /
    • pp.2985-2989
    • /
    • 2014
  • Autophagy is a self-digestion process in which intracellular structures are degraded in response to stress. Notably, prolonged autophagy leads to cell death. In this study, we investigated whether CX-4945, an orally available protein kinase 2 (CK2) inhibitor, induces autophagic cell death in human cervical cancer-derived HeLa cells and in human prostate cancer-derived LNCaP cells. CX-4945 treatment of both cell lines resulted in the formation of autophagosomes, in the conversion of microtubule-associated protein 1 light chain 3 (LC3), and in down-regulation of the Akt-mammalian target of rapamycin (mTOR)-p70 ribosomal protein S6 kinase (S6K) signaling cascade. Thus, pharmacologic inhibition of CK2 by CX-4945 induced autophagic cell death in human cancer cells by down-regulating Akt-mTOR-S6K. These results suggest that autophagy-inducing agents have potential as anti-cancer drugs.

Dynamic Gene Expression Profiling of Escherichia coli in Carbon Source Transition from Glucose to Acetate

  • Oh Min-Kyu;Cha Mee-Jeong;Lee Sun-Gu;Rohlin Lars;Liao James C.
    • Journal of Microbiology and Biotechnology
    • /
    • 제16권4호
    • /
    • pp.543-549
    • /
    • 2006
  • DNA microarray was used to study the transcription profiling of Escherichia coli adapting to acetate as a sole carbon source. Bacteria grown in glucose minimal media were used as a reference. The dynamic expression levels of 3,497 genes were monitored at seven time points during this adaptation. Among the central metabolic genes, the glycolytic and glucose phosphotransferase genes were repressed as the bacteria entered stationary phase, whereas the glyoxylate pathway, TCA cycle, and gluconeogenic genes were induced. Distinct induction or repression patterns were recognized among different pathway genes. For example, the repression of glycolytic genes and the induction of gluconeogenic ones started immediately after glucose was depleted. On the other hand, the regulation of the pentose phosphate pathway genes and glyoxylate genes gradually responded to the glucose depletion or was more related to growth in acetate. When the whole genome was considered, many of the CRP, FadR, and Cra regulons were immediately responsive to the glucose depletion, whereas the $\sigma^s$, Lrp, and IHF regulons were gradually responsive to the glucose depletion. The expression profiling also provided differential regulations between isoenzymes; for example, malic enzymes A (sfcA) and B (maeB). The expression profiles of three genes were confirmed with RT-PCR.