• Title/Summary/Keyword: L-NAME

Search Result 449, Processing Time 0.022 seconds

Density Functional Theory Study of Silicon Chlorides for Atomic Layer Deposition of Silicon Nitride Thin Films

  • Yusup, Luchana L.;Woo, Sung-Joo;Park, Jae-Min;Lee, Won-Jun
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2014.02a
    • /
    • pp.211.1-211.1
    • /
    • 2014
  • Recently, the scaling of conventional planar NAND flash devices is facing its limits by decreasing numbers of electron stored in the floating gate and increasing difficulties in patterning. Three-dimensional vertical NAND devices have been proposed to overcome these issues. Atomic layer deposition (ALD) is the most promising method to deposit charge trap layer of vertical NAND devices, SiN, with excellent quality due to not only its self-limiting growth characteristics but also low process temperature. ALD of silicon nitride were studied using NH3 and silicon chloride precursors, such as SiCl4[1], SiH2Cl2[2], Si2Cl6[3], and Si3Cl8. However, the reaction mechanism of ALD silicon nitride process was rarely reported. In the present study, we used density functional theory (DFT) method to calculate the reaction of silicon chloride precursors with a silicon nitride surface. DFT is a quantum mechanical modeling method to investigate the electronic structure of many-body systems, in particular atoms, molecules, and the condensed phases. The bond dissociation energy of each precursor was calculated and compared with each other. The different reactivities of silicon chlorides precursors were discussed using the calculated results.

  • PDF

The Etymology of Scientific Names for Korean Mammals

  • Jo, Yeong-Seok;Koprowski, John L.;Baccus, John T.;Yoo, Jung-Sun
    • Animal Systematics, Evolution and Diversity
    • /
    • v.37 no.3
    • /
    • pp.255-272
    • /
    • 2021
  • Etymologies are explanations of what our words meant and how they sounded 600 to 2,000 years ago. When Linnaeus in the mid-1700s began naming animals with a binomial nomenclature, he based names on the Latin Grammatical Form. Since many names have Latin or Greek roots, the name for an animal is the same throughout the world because Latin is no longer a spoken language and meanings of names will not evolve or change. In his use of Latin or a Latinized word for the genus and species, Linnaeus used descriptive words that will always be the same. Notwithstanding the importance of etymologies for scientific names, no study has addressed the etymology of scientific names for Korean mammals. Here, we list etymologies for scientific names of 127 mammal species, 84 genera, 32 families, and 8 orders from Korea. The origins of etymologies are mostly based on morphology, color of pelage, behavior, distribution, locality, country name, or a person's name. This paper will be useful for new students and trained scholars studying Korean mammals.

The Relaxant Activity of Safranal in Isolated Rat Aortas is Mediated Predominantly via an Endothelium-Independent Mechanism - Vasodilatory mechanism of safranal -

  • Razavi, Bibi Marjan;Amanloo, Mojtaba Alipoor;Imenshahidi, Mohsen;Hosseinzadeh, Hossein
    • Journal of Pharmacopuncture
    • /
    • v.19 no.4
    • /
    • pp.329-335
    • /
    • 2016
  • Objectives: Safranal is a pharmacologically active component of saffron and is responsible for the unique aroma of saffron. The hypotensive effect of safranal has been shown in previous studies. This study evaluates the mechanism for the vasodilatory effects induced by safranal on isolated rat aortas. Methods: To study the vasodilatory effects of safranal (0.2, 0.4 and 0.8 mM), we contracted isolated rat thoracic aorta rings by using $10^{-6}-M$ phenylephrine (PE) or 80-mM KCl. Dimethyl sulfoxide (DMSO) was used as a control. The vasodilatory effect of safranal was also evaluated both on intact and denuded endothelium aortic rings. Furthermore, to study the role of nitric oxide and prostacyclin in the relaxation induced by safranal, we incubated the aortic rings by using L-NAME ($10^{-6}M$) or indomethacin ($10^{-5}M$), each for 20 minutes. Results: Safranal induced relaxation in endothelium-intact aortic rings precontracted by using PE or KCl in a concentration-dependent manner, with a maximum relaxation of more than 100%. The relaxant activity of safranal was not eliminated by incubating the aortic rings with L-NAME ($EC_{50}=0.29$ vs. $EC_{50}=0.43$) or with indomethacin ($EC_{50}=0.29$ vs. $EC_{50}=0.35$), where $EC_{50}$ is the half maximal effective concentration. Also, the vasodilatory activity of safranal was not modified by endothelial removal. Conclusion: This study indicated that relaxant activity of safranal is mediated predominantly through an endothelium-independent mechanism.

EFFECTS OF NITRIC OXIDE SYNTHASE INHIBITORS ON OSTEOCLAST-LIKE CELL FORMATION

  • Ahn, Seung-Kyu;Kim, Jung-Kun;Cha, Kyung-Suk
    • The korean journal of orthodontics
    • /
    • v.25 no.6 s.53
    • /
    • pp.715-722
    • /
    • 1995
  • Orthodontic tooth movement in response to orthodontic force results from actions of osteoclasts and osteeoblasts in the cell level. Convincing evidence has now been provided to support the view that osteoclasts are derived from mononuclear cells that originate in the bone marrow or other hematopoietic organs and they migrate to the bones via vascular routes. Nitric oxide(NO), which accounts for the biological properties of endothelium-derived relaxing factor(EDRF), is the endogenous stimulator of soluble guanylate cylase. The discovery of the formation of nitric oxide(NO) from L-arginine in mammalian tissues and its biological roles has, in the last 7 years, thrown new light onto many areas of research. Data from experiments in vitro showed that N-metyl-L-arginine(L-NMA) and L-nitro-L- arginine(L-NAME) are competitive inhibitors of nitric oxide synthase. This study suggest that the multinucleated cells in our culture have characteristics of osteoclasts and that the potential bone cell activity of nitric oxide in vitro may be mediated in part by stimulation of marrow mononuclear cells to form osteoclast-like cells. Bone marrow cells were obtaineed from tibia of 19-days old chick embryo. After sacrifice, tibia was quickly dissected and the bone were then split to expose the medullary bone. The cells were attached for 4 hours and the nonadherent cells were collected. Marrow cells weere cultured in 96-well plate in medium 199. To examine the number of TRAP-positive multinucleated cells(MNCs), $10^{-8}\;M\;Vit=D_3$ and various concentration of L-NMA and L-NAME weere added at the beginning of cultures and with each medium change. After 7 days of culture. tartrate-resistant acid phosphatase(TRAP) staining was performed for microscopic evaluation. Cells haying more than three nuclei per cell were counted as MNCs. The obsrved results were as follows;1. 1,25-dihydroxyvitamine $D_3$ stimulated the osteoclast-like multinucleated cells in cultures of chick embryo bone marrow. 2. Nitric oxide synthase inhibitors(NOSI ; N-NMA, N-NAME) stimulated the osteoclast-like cells in cultures of chick embry bone marrow. 3. 1,25-dihydroxyvitamine$D_3$ and nitric oxide synthase inhibitors did not appear to have additive effect on the generation of TRAP-positive MNCs. These results suggest that nitric oxide synthase inhibitors may stimulate the osteoclast-like multinucleated cell formation and fusion in cultures of chick bone marrow.

  • PDF

Effect of Inhibitor of Nitric Oxide Synthesis on the Ischemic Reconditioning in Isolated Heart of Rat. (NO 억제제가 허혈전처치의 심장 보호효과에 미치는 영향)

  • 유호진;조은용
    • Journal of Chest Surgery
    • /
    • v.29 no.8
    • /
    • pp.807-815
    • /
    • 1996
  • The protective effect of'ischemic preconditioning'on ischemid-reperfusion injury of heart has been reported in various animal species. but without known mechAnism in detail, In An attempt to investigate the cardioprotective mechanism of ischemic preconditioning, we examined the effects of nitric oxide(UO) synthesis in preconditioned heart of rat The isolated hearts perfused by Langendorfr's method were ex- posed to 30min global ischemia followed by 30min reperfusion with oxygenated Krebs-Henseleit(K-H) sol- ution. Ischemic preconditioning was performed with three episodes of Sm n ischemia and Smin repeyfusion before the induction of prolong ischemia(30min)-reperfusion(30min). Ischemic preconditioning prevented the depression of cardiac function(left ventricular pressure .K heart rate) observed in the ischemia- reperfusion hearts and reduced the release of lactate dehydrogenase during the reperfusion period. On electromicroscopic pictures, myocardial ultrastructures wore relatively well preserved in isthemic preconditioned hearts. N6_nitro-L-arginine methyl ester(L-NAME) an inhibitor of L-arginine citric oxide pathway, was infused at a rate O.Smllmin In a dose of 10mg kg-1 before the initial ischemic preconditioning. neither the protection of cardiac function nor the reduction of LDH releAse in ischemic preconditioning hearts was altered in the presence of added L-NAME On ultrastructural finding, the preservation of morphology in ischemic preconditioning heart was not change by the pretreatment of L-UAME. The failure of the WO synthesis inhibitor to reduce t e effect of ischemic preconditioning may be related to be species specific in that NO may allot be the trigger for ischemic preconditioning in rats.

  • PDF

Diesel Exhaust Particles and Airway Inflammation: Effect of Nitric Oxide Synthase Inhibitors

  • Lim, Heung-Bin;Lee, Dong-Wook
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.18 no.E2
    • /
    • pp.121-128
    • /
    • 2002
  • This study was carried out to investigate if nitric oxide synthase (NOS) inhibitors modulate airway inflammation induced by diesel exhaust particles (DEP). N$\^$G/-nitro-L-arginine methyl ester (L-NAME), a potent constitutive NOS (cNOS) inhibitor, and aminoguanidine (AG), a selective inducible NOS (iNOS) inhibitor, were administered to mice in their drinking water for 7 weeks. Airway inflammation was elicited by the repeated intratracheal administration of DEP. The results showed that macrophages, inflammatory eosinophils and neutrophils in bronchoalveolar lavage (BAL) fluids by intratracheal DEP instillation were significantly suppressed in the mice treated with two NOS inhibitors toghther with DEP. The suppression of these cells was more effective in AG treated groups than in L -NAME treated groups. NOS inhibitor treatment also reduced interleukin -5 (IL-5 in the BAL fluids and lung homogenates. Additionally, it was found that eosinophil peroxidase (EPO) activity in the BAL fluids was also decreased by NOS inhibitor treatment. These results suggest that nitric oxide (NO) is produced in airway inflammation by repeated DEP instillation, and that iNOS inhibition as well as cNOS inhibition can play a modulating role in this airway inflammation by DEP.

Roles of Nitric Oxide in Vestibular Compensation

  • Jeong, Han-Seong;Jun, Jae-Yeoul;Park, Jong-Seong
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.7 no.2
    • /
    • pp.73-77
    • /
    • 2003
  • The effects of nitric oxide on the vestibular function recovery following unilateral labyrinthectomy (UL) were studied. Sprague-Dawley male rats, treated with nitric oxide liberating agent sodium nitroprusside (SNP) and NOS inhibitor $N^G$-nitro-L-arginine methyl ester (L-NAME), were subjected to destruction of the unilateral vestibular apparatus, and then spontaneous nystagmus was observed in the rat. To explore the effects of nitric oxide on the neuronal excitability, whole cell patch clamp technique was applied on isolated medial vestibular nuclear neurons. The frequency of spontaneous nystagmus in SNP treated rats was lesser than that of spontaneous nystagmus in control animals. In contrast, pre-UL treatment with L-NAME resulted in a significant increase in spontaneous nystagmus frequency. In addition, SNP increased the frequency of spontaneous action potential in isolated medial vestibular nuclear neurons. Potassium currents of the vestibular nuclear neurons were inhibited by SNP. After blockade of calcium dependent potassium currents by high EGTA (11 mM) in a pipette solution, SNP did not inhibit outward potassium currents. 1H-[1,2,4] oxadiazolo [4,3-a] quinozalin-1-one (ODQ), a specific inhibitor of soluble guanylyl cyclase, inhibited the effects of SNP on the spontaneous firing and the potassium current. These results suggest that nitric oxide after unilateral labyrinthectomy would help to facilitate vestibular compensation by inhibiting calcium-dependent potassium currents through increasing intracellular cGMP, and consequently would increase excitability in ipsilateral vestibular nuclear neurons.

Study on the Mechanism of Vascular Relaxation of Ethanol Extract of Persicaria Perfoliata H. Gross (하백초 에탄올 추출물의 혈관이완 기전에 대한 연구)

  • Kim, Hye-Yoom;Choi, Byung-Sun;Choi, Eun-Hee;Cui, Hao-Zhen;Kang, Dae-Gill;Lee, Ho-Sub
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.23 no.2
    • /
    • pp.389-396
    • /
    • 2009
  • The ethanol extract of Persicaria perfoliata (EPP) induced relaxation of the phenylephrine-precontracted aorta in a dose-dependent manner, which was abolished by removal of functional endothelium. Pretreatment of the aortic tissues with NG-nitro-L-arginine methyl ester (L-NAME) or 1H-[1,2,4}-oxadiazole-[4,3-${\alpha}$)-quinixalin-1-one (ODQ) inhibited the relaxation induced by EPP. However, EPP-induced relaxation was not blocked by pretreatment with indomethacine, glibenclamide, tetraethylammonium (TEA), atropine, or propranolol. Incubation of endothelium-intact thoracic aortic ring with EPP increased the production of cGMP, which was also blocked by pretreatment with L-NAME or ODQ. These results suggest that EPP dilates vascular smooth muscle via endothelium-dependent NO/cGMP signaling.

Non-adrenergic non-cholinergic relaxation and contraction in circular smooth muscle of bovine reticular groove (소(우(牛)) 식도구 윤상근의 비아드레날린 비콜린성 이완 및 수축)

  • Kang, Tong-mook;Han, Ho-jae;Yang, Il-suk
    • Korean Journal of Veterinary Research
    • /
    • v.35 no.2
    • /
    • pp.279-285
    • /
    • 1995
  • To characterize non-adrenergic non-cholinergic(NANC) nerve mediated contractile responses in circular smooth muscle of bovine reticular groove, we investigated NANC relaxation and contraction induced by electric field stimulation to enteric nerves. In the presence of atropine($1{\mu}M$) and guanethidine($50{\mu}M$), electric field stimulation at frequency of 1 to 16Hz(square pulses, 0.5ms duration, 70V) evoked clear-cut relaxations through stimulations. Transient 'rebound contraction' was occured when the stimulus was switched off. All of the responses (relaxation and rebound contraction) were dose-dependently blocked by Nw-nitro-$_{\small{L}}$-arginine methyl ester(L-NAME), an inhibitor of nitric oxide synthesis, and methylene blue, and inhibitor of soluble guanylate cyclase. Tetraethyl ammonium(TEA), a potassium channel blocker, did not block the NANC relaxations.

  • PDF

Effect of Ginseng Saponin on Hypothalamus-Pituitary- Adrenal Axis under Stress in Mice

  • Do Hoon Kim;Jun
    • Proceedings of the Ginseng society Conference
    • /
    • 1998.06a
    • /
    • pp.83-89
    • /
    • 1998
  • Ginseng total saponins (GTS) injected intracerebroventricularly (i.c.v.) at doses from 0.1-1 vs inhibited the i.c.v. injection stress-induced plasma corticosterone levels in mice. The inhibitory action of GTS was blocked by co-administered NG-nitro-L-arginine methyl ester (L-NAME; 1.5 us, i.c.v.), an. inhibitor of nitric oxide synthase (NOS). Of the ginsenosides Rbl, Rba, Rc, Rd, Re, Rf, Rgl,20(S)-Rg3, and 20(R)-Rg3 injected i.c.v. at doses from 0.01 to 0.3ug(or 1 uE),20(5)-Rg3 and Rc significantly inhibited the o.c.v. injection stress-induced Plasma corticosterone levels. The inhibitory actions of 20(S)-Rg3 and Rc were blocked by co-administered L-NAME (1.5 n, i.c.v.). These results suggest that G75, 20(S)-Rg3 and Rc may inhibit the i.c.v. injection stress-induced hypothalamo-pituitary-adrenal response by inducing NO production in the brain.

  • PDF