• 제목/요약/키워드: 5㎓

검색결과 353,317건 처리시간 0.164초

5-Hydroxytryptamine(5-HT)이 개의 신장기능에 미치는 영향 (Effect of 5-Hydroxytryptamine(5-HT) on Renal Function in Dog)

  • 고석태;나한광;최인
    • Biomolecules & Therapeutics
    • /
    • 제4권1호
    • /
    • pp.7-18
    • /
    • 1996
  • 5-Hydroxytryptamine(5-HT, serotonin), when given into the vein, produced antidiuretic action accompanied with reduction of glomerular filtration(GFR), renal plasma flow(RPF), osmolar clearance(Cosm) and amounts of sodium or potassium excreted in urine( $E_{Na}$ , $E_{K}$), with the augmented reabsorption rates of sodium and potassium in renal tubules. 5-HT, when infused into a renal artery, exhibited diuretic action accompanied with the augmented RPF and increased $E_{Na}$ and $E_{K}$ in only infused kidney. Antidiuretic action of 5-HT infused into the vein was not influenced by ketanserin, 5-H $T_2$receptor blockade, given into a renal artery, vein or carotid artery, by methysergide, 5-H $T_1$receptor blockade, given into a renal artery, whereas above antidiuretic action was inhibited by methysergide given into vein or carotid artery. Diuretic action of 5-HT infused into a renal artery in only experimental kidney was blocked by ketanserin injected into a renal artery, was not influenced by methysergide administered into a renal artery. Above results suggest that 5-hydroxytryptamine(5-HT) produced the antidiuretic action through central 5-H $T_1$receptor and the diuretic action through 5-H $T_2$receptor located in renal tubules of kidney.ney.

  • PDF

Synthesis and Cytotoxicity of Some Rigid Derivatives of Methyl 2,5-Dihydroxycinnamate

  • Nam, Nguyen-Hai;Kim, Yong;You, Young-Jae;Hong, Dong-Ho;Kim, Hwan-Mook;Ahn, Byung-Zun
    • Archives of Pharmacal Research
    • /
    • 제25권5호
    • /
    • pp.590-599
    • /
    • 2002
  • Eight rigid compounds designed as esterase-stable analogues of methyl 2,5-dihydroxycinnamate (1) were synthesized. These derivatives include 2-(2',5'-dihydroxybenzylidene)cyclopentenone (3a), 2-(2',5'-dihydroxybenzylidene)cyclohexanone (3b), 2,6-bis(2',5'-dihydroxybenzy-lidene)cyclohexanone (4b), 2,6-bis(2',5'-dihydroxybenzylidene)cyclopentenone (4a), (E)-3-(2',5'-dihydroxybenzylidene)pyrrolidin-2-one (5), (E)-5-(2',5'-dihydroxybenzylidene )-1,2-isothiazolidine-1,1-dioxide (6), 4-(2',5'-dihydroxyphenyl)-5H-furan-2-one (7), and 3-(2',5'-dihydroxyphenyl)cyclopent-2-ene-1-one (8). Among the eight compounds, the furanone 7 and cyclopentenone 8 showed the most potent cytotoxicity with $IC_{50}$ values of 0.39-0.98 $\mu\textrm{g}$/mL. Compound 8 was further brominated, phenylated and methylated at the a position to give three corresponding analogues, including 2-bromo-3-(2',5'-dihydroxyphenyl)cyclopent-2-ene-1-one (24), 3-(2',5'-dihydroxyphenyl)-2-phenylcyclopent-2-ene-1-one (27), and 3-(2',5'-dihydroxyphenyl)-2-methylcyclopent-2-ene-1-one (28). Among the three, the most enhanced activity was observed with the phenylated compound 27.

공상 소방공무원의 안전보건에 관한 연구 - 경북지역을 중심으로 - (A Study on Safety and Health of Injured Firefighter: Focusing on Gyeongbuk Province)

  • 방창훈
    • 한국화재소방학회논문지
    • /
    • 제23권5호
    • /
    • pp.167-172
    • /
    • 2009
  • 본 연구는 경북지역 공상 소방공무원에 관한 안전보건 사항을 조사하여 소방공무원의 안전보건을 향상시킬 수 있는 기초자료를 제공하기 위하여 수행되었으며, 연구결과는 다음과 같다. 공상 소방공무원의 사고시 업무분야를 조사한 결과 화재진압업무(42.5%), 구급업무(20.0%), 구조업무(12.5%), 운전(10.0%), 기타업무(10.0%), 교육훈련(5.0%)의 순으로 나타났다. 또한 공상 소방공무원의 75%가 입원을 하였으며 수술은 62.5%, 그리고 장애를 입은 경우가 25.0%로 나타났으며, 소방공무원의 안전보건을 위한 필요 사항으로는 행재정적지원(42.5%), 교육자료 개발보급(12.5%), 교육연수지원(12.5%), 기관장 관심 및 지원(7.5%), 소방공무원 의식개선(2.5%)로 조사되었다.

Design and Synthesis of Bioisosteres of Ultrapotent Protein Kinase C(PKC) Ligand, 5-Acetoxymethyl-5-hydroxymethyl-3-alkylidene tetrahydro-2-furanone

  • Lee, Jee-Woo
    • Archives of Pharmacal Research
    • /
    • 제21권4호
    • /
    • pp.452-457
    • /
    • 1998
  • Three compounds, 5-(acetoxymethyl)-5-(hydroxymethyl)-3-tetradecyl-2,5-dihydro-2-furanone (3), 5-(acetoxymethyl)-5-(hydroxymethyl)-3,3-dihexyltetrahydro-2-furanone (4) and 5-(acetoxymethyl)-5-(hydroxymethyl)-3,3-dioctyltetrahydro-2-furanone (5), were designed and synthesized as surrogates of the ultrapotent DAG analogue, 5-(acetoxymethyl)-5-(hydroxymethyl) 3-[(Z)-tetradecylideneltetrahydro-2-furanone (1), a compound that showed high affinity for PKC-$\alpha$ ($K_1$=35 nM) in a competition binding assay with [$^3H$-20]phorbol-12,13-dibutyrate (PDBU). In an attempt to overcome the problem of generating geometrical E- and Z- isomers, as encountered with 1, the double bond was moved to an endocyclic location as in 3, or an additional alkyl chain was appended to C3 to give the corresponding 3,3-dialkyl saturated lactones (4 and 5). The lactone was constructed from glycidyl-4-methoxyphenyl ether in 5 steps. The target compounds showed reduced binding affinities for PKC-.alpha. with $K_{i}$ values of 192 nM (3), 4,829 nM (4), and 2,812 nM (5), respectively. These results indicate that constrained DAG analogues having a tetrahydro-2-furanone template are effectively discriminated by PKC-(X in terms of the direction of the long alkyl chain connected to the 3-position.n.

  • PDF

저Pb Sn-5%Pb-1.5%Ag-x%Bi계 솔더 합금의 특성에 관한 연구 (A study on the characteristics of low Pb Sn-5%Pb-1.5%Ag-x%Bi solder alloys)

  • 홍순국;주철홍;강정윤;김인배
    • Journal of Welding and Joining
    • /
    • 제16권3호
    • /
    • pp.157-166
    • /
    • 1998
  • Recently as environmental pollution caused by Pb has posed a serious threat to the global environment, the trend to regulate the usage of Pb in electronic industry is one the rise. Currently, the solder alloy with high Pb content, Sn-37%Pb, is utilized in the electronic assembly therefore, the objective of this study is to develop an alternative solder alloy for the existing Sn-37%Pb solder alloy. First thing, this work choosed Sn-5%Pb-1.5%Ag, Sn-5%Pb-1.5%Ag-x%Bi(x=1~5%) for candidate solder alloys, and examined their properties such as melting range, wettability, microhardness, tensile property, oxidation behavior and microstructure. Wettability was on the same level of Sn-37%Pb. Dissolution of Pb ion in Sn-5%Pb solder was 0.46ppm. This solder alloy revealed cellular dendrite microstructure $\beta$-Sn matrix, Pb-rich phase, Ag/Sn, and Cu/Sn Intermetallic compounds. The range of solidification temperature was within 3$0^{\circ}C$. Also these alloy displayed higher tensile strength and lower elongation than Sn-37%Pb. The resistance of oxidation in Sn-5%Pb-1.5%Ag solder alloy was superior to that of Sn-37%Pb solder alloy. But that of Sn-5%Pb-1.5%Ag-5%Bi solder alloy was equal to that of Sn-37%Pb solder alloy.

  • PDF

Nitrided Pressureless Sintering에 의해 제조된 Si3N4의 산화거동 (Oxidation Behavior of Si3N4 by the Nitrided Pressureless Sintering)

  • 한인성;천승호;정용희;서두원;이시우;홍기석;우상국
    • 한국세라믹학회지
    • /
    • 제42권1호
    • /
    • pp.62-68
    • /
    • 2005
  • 질화상압동시소결(NPS) 공정에 의해 제조된 기공율이 다른 질화규소 소결체에 대해 $1300^{circ}C$ 순산소 가스분위기에서 산화거동을 조사하였다. 질화규소 세라믹스 표면에 형성된 산화층의 두께는 산화 시간과 온도에 따라 증가되었으며, $1300^{circ}C$에서 100시간 산화시킨 5A5Y5Si와 5A5Y10Si 시편의 산화층 두께는 각각 10$\mu$m와 20$\mu$m이었다. 5A5YSi와 5A5Y10Si 시편의 산화는 각각 215kJ/mol과 104kJ/mol의 활성화 에너지를 갖고 포물선적 거동을 나타내었다. $1300^{circ}C$에서 500시간 산화시킨 후, 5A5Y5Si 시편에 대해 꺾임 강도를 측정한 결과, 초기의 약 500MPa값을 유지하고 있었으며, 반면 5A5Y10Si의 경우에는 초기의 값에서 약 100MPa의 강도저하를 나타내고 있었다.

화학적 합성법에 의한 금속수소화물의 제조 및 수소화 속도론적 연구 (Preparation of Metal Hydrides Using Chemical Synthesis and Hydriding Kinetics)

  • 이윤성;오재완;문성식;남기석
    • 공업화학
    • /
    • 제9권2호
    • /
    • pp.255-260
    • /
    • 1998
  • 금속수소화물 $LaNi_5$$LaNi_{4.5}Al_{0.5}$을 화학적 합성법으로 제조하여, 합성된 금속수소화물의 물성을 다양한 방법으로 확인하였다. $LaNi_5$$LaNi_{4.5}Al_{0.5}$은 2회 정도 수소화/탈수소화 반응을 시키면 활성화되었으며, 압력-농도-온도 곡선을 측정한 결과 각각 6개와 5.5개의 수소원자가 저장되었다. $LaNi_{4.5}Al_{0.5}$의 경우 수소화 반응속도를 초기속도법으로 구한 결과 비반응 수축핵모델이 잘 적용되었으며, 수소화반응의 율속단계는 $LaNi_{4.5}Al_{0.5}$의 표면에서 수소분자의 해리화학흡착임을 알 수 있었다. $LaNi_{4.5}Al_{0.5}$의 수소화반응 활성화에너지는 $9.506kcal/mol-H_2$이었으며, 반응속도식은 273~343K와 $P_o-P_{eq}=0.25{\sim}0.66atm$의 범위에서 아래와 같이 표시되었다. $\frac{dX}{dt}=4.636(P_o-P_{eq})$ exp$\frac{-9506}{RT}$).

  • PDF

유기티탄 화학 (제4보). $TiCl(OC_6H_5)_3{\cdot}C_6H_5OH\;및\;Ti(OC_6H_5)_4{\cdot}C_6H_5OH$의 분자 및 전자구조 (Organotitanium Chemistry (IV). The Molecular and Electronic Structure of $TiCl(OC_6H_5)_3{\cdot}C_6H_5OH\;and\;Ti(OC_6H_5)_4{\cdot}C_6H_5OH$)

  • 이후성;어용선;손연수
    • 대한화학회지
    • /
    • 제19권2호
    • /
    • pp.92-97
    • /
    • 1975
  • $TiCl(OC_6H_5)_3{\cdot}C_6H_5OH\;및\;Ti(OC_6H_5)_4{\cdot}C_6H_5OH$의 분자량 측정과 전자 흡수스펙트럼을 고찰함으로써 이들 두 유기-리탄 화합물들의 용액 상태에서의 분자 및 전자구조에 대하여 연구하였다. $Ti(OC_6H_5)_4{\cdot}C_6H_5OH$는 고체상태에서는 이합체로 존재하지만 분자량 측정 결과 묽은 용액에서는 단위체로 완전해리되며 $TiCl(OC_6H_5)_3{\cdot}C_6H_5OH$도 8mM농도에서 해리를 시작함을 알수 있었다. 따라서 이들 두 착화합물은 묽은 용액에서 5배위 착화합물로 존재하며 분자구조는 trigonalbipyramid으로 생각된다. 두 화합물의 전자 흡수스펙트럼은 자외부쪽에 똑같은 진동구조를 갖는 벤젠고리 특유의 흡수밴드를 나타내며 가시부에서는 $TiCl(OC_6H_5)_3{\cdot}C_6H_5OH$의 경우 26.8kK에 $Ti(OC_6H_5)_4{\cdot}C_6H_5OH$는 29.6kK에 각각 흡수 밴드를 나타낸다. 이가시부 흡수밴드는 리간드에서 금속쪽으로 전하이전에 의한 $^1A_1''{\to}^1E'\;or\;^1E''$ 전이로 생각된다.

  • PDF

$Zn_{0.5}Mg_{0.5}Te$$Zn_{0.5}Mg_{0.5}Te:Co$ 단결정 성장과 열역학 함수 추정 (Growth and Thermodynamic Function Properties of Undoped and Co-doped $Zn_{0.5}Mg_{0.5}Te$ Single Crystals)

  • 김용근
    • 한국진공학회지
    • /
    • 제3권2호
    • /
    • pp.198-202
    • /
    • 1994
  • Zn0.5Mg0.5Te 및 Zn0.5Mg0.5Te:Co 단결정을 온도진동법을 응용한 화학수송법으로 성장시켰고, 광 학적 energy gap의 온도의존성은 Varshni의형식에 잘 적용되었다. 광학적 energy gap의 온도의존성으 로부터 열역학 기본함수인 entropy, enthalpy, heat capacity를 구했다.

  • PDF