• 제목/요약/키워드: plasma synthesis

검색결과 466건 처리시간 0.029초

Contact resistance of mos2 field effect transistor based on large area film grown using chemical vapor deposition compares to depend on 3-type electrodes

  • 김상정;김성현;박성진;박명욱;유경화
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.277.1-277.1
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    • 2016
  • We report on synthesis of large-area MoS2 using chemical vapor deposition (CVD). Relatively uniform MoS2 are obtained. To fabricate field-effect transistor (FET) devices, MoS2 films are transferred to another SiO2/Si substrate using polystyrene (PS) and patterned using oxygen plasma. In addition, to reduce contact resistance, synthesis of graphene used as channel. Device characteristics are presented and compared with the reported results.

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Membrane Hyperpolarization Increases cAMP to Induce the Initiation of Sperm Motility in Salmonid Fishes, Rainbow Trout and Masu Salmon

  • Kho, Kang-Hee;Morisawa, Masaaki;Choi, Kap-Seong
    • Journal of Microbiology and Biotechnology
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    • 제13권6호
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    • pp.833-840
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    • 2003
  • Sperm motility of salmonid fishes is suppressed by external $K^{+}$ and initiated by decrease of $K^{+}$ concentration surrounding the sperm. It was shown that the decrease in external $K^{+}$ concentration induced not only the initiation of sperm motility, but also hyperpolarization of the plasma membrane and synthesis of cAMP in the sperm of rainbow trout, steelhead trout, and masu salmon. Inhibitors of $K^{+}$ channels, especially voltage-dependent $K^{+}$ channels, inhibited these three reactions, and the inhibitions were abolished by subsequent addition of a $K^{+}$ ionophore, valinomycin, suggesting that $K^{+}$ efflux through the $K^{+}$ channel contributes to rapid changes in the membrane potential of sperm and cAMP synthesis, thereby resulting in the initiation of sperm motility of salmonid fishes.

Synthesis of $\beta$-Sitosterol Esters with Conjugated Linoleic Acid and Medium Chain Fatty Acids by Using Lipase as Catalyst

  • Vu, Phuong-Lan;Lee, Ki-Teak
    • 한국식품저장유통학회:학술대회논문집
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    • 한국식품저장유통학회 2003년도 춘계총회 및 제22차 학술발표회
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    • pp.104.2-105
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    • 2003
  • Plant steryl esters have good effects on plasma cholesterol level and are used as functional food ingredient. Conjugated linoleic acid (CLA) presents mainly in animal foods and has a good benefit and medium chain fatty acids (MCFAs) are a rapid energy source for human. In this study, we produced the ${\beta}$-sitosterol esters from CLA and MCFAs using various lipases as catalysts. Among lipases, AYS (from Candida rugosa) was the most effective for synthesis of ${\beta}$-sitosterol esters in the presence of water (24.35% conversion) or hexane (25.33% conversion). The second esterification extent was obtained by lipase AK (from Pseudomonas sp), showing 10.26% conversion in water and 15.94% conversion in hexane, respectively. The reaction condition was 1:3 molar ratio (${\beta}$-sitosterol:fatty acid, 1:3) and stirred (175 rpm) at 55$^{\circ}C$ in water bath shaker for 48h.

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Solvothermal Synthesis of Copper Indium Diselenide in Toluene

  • Chang, Ju-Yeon;Han, Jae-Eok;Jung, Duk-Young
    • Bulletin of the Korean Chemical Society
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    • 제32권2호
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    • pp.434-438
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    • 2011
  • Polycrystalline $CuInSe_2$ (CIS) was synthesized through solvothermal reactions in toluene with selected alkyl amines as complexing agents. The alkyl amines were used as reducing agent of selenium and catalytic ligands, enhancing the formation of CIS compounds in the colloidal solution. Toluene does not contribute the syntheses directly but minimizes the amounts of amines required for single phase CIS. We systematically studied the reactivity of amine compounds for the solovothermal syntheses, determined critical concentration of amine and the shortest reaction time. Crystallinity, morphology, chemical composition, and band gap of the prepared $CuInSe_2$ were respectively measured by X-ray diffraction, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy and UV-vis spectroscopy.

Effect of Hematoxylin on Glucose Metabolism in Soleus Muscle of Streptozotocin-Induced Diabetic Rats

  • Moon, Chang-Kju;Chung, Yi-Sook;Hwang, Gwi-Seo
    • 한국식품위생안전성학회지
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    • 제7권1호
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    • pp.53-58
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    • 1992
  • 천연 색소성분의 하나인 hematoxylin은 Streptozotocin으로 유도한 당뇨병쥐에서 혈당강하 효과를 나타내는 것으로 관찰되었으며, 이때 혈중 insulin치에는 영향을 미치지 않았다. 혈당강하기전 연구의 일환으로 당뇨병쥐의 soleuo muscle에서의 포도당 대사에 미치는 영향을 검토한 결과 in vivo 및 in vitro 실험 모두에서 대사능이 증가되었고 이는 포도당대사 과정에서의 insulin 작용의 강화와 glycgen 합성의 증가에 기인하는 것으로 추정된다.

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Gram-Positive Bacteria Specific Properties of Silybin Derived from Silybum marianum

  • Lee, Dong-Gun;Kim, Hyung-Keun;Park, Yoon-Kyung;Park, Seong-Cheol;Woo, Eun-Rhan;Jeong, Hye-Gwang;Hahm, Kyung-Soo
    • Archives of Pharmacal Research
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    • 제26권8호
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    • pp.597-600
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    • 2003
  • Silybin has a potent antibacterial activity, more potent than silymarin II, against gram-positive bacteria without hemolytic activity, whereas it has no antimicrobial activity against gram-negative bacteria or fungi. The mode of action of silybin against the gram-positive bacterial cell was examined by investigating the change in plasma membrane dynamics of bacterial cells using 1 ,6-diphenyl-1,3,5-hextriene (DPH) as a membrane probe and by assessing the inhibition of macromolecular synthesis using radiolabeled incorporation assay. The results showed that silybin inhibited RNA and protein synthesis on gram-positive bacteria.

고려인삼의 파낙사다이올은 트롬빈 유인 혈소판응집반응에서 트롬복산 A2의 생성을 저해한다 (Panaxadiol from Panax ginseng C.A. Meyer Inhibits Synthesis of Thromboxane $A_2$ in Platelet Aggregation Induced by Thrombin)

  • Park, Hwa-Jin;Rhee, Man-Hee;Park, Kyeong-Mee;Nam, Ki-Yeul;Park, Ki-Hyun
    • Journal of Ginseng Research
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    • 제17권2호
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    • pp.131-134
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    • 1993
  • Panaxadiol (PD) from Korean red ginseng C.A. Meyer did not control the concentration of cytosolic free $Ca^{2+}$ influxes by thrombin (5 $\mu$/ml). However, PD strongly inhibited the synthesis of thromboxane. $A_2$ (TX$A_2$) in the aggregation of human platelets induced by thrombin (5 $\mu$/ml). These rexults suggest that PD blocks the any Pathway transforming to TX$A_2$ from arachidonic acid (AA) which release out of plasma membrane phospholipids by $Ca^{2+}$-dependent phospholipase C or phospholipase $A_2$. It may be also concluded that PD has the antiplatelet function by inhibiting the synthesis of TX$A_2$, which known to be the potent stimulator of the aggregation of human platelet.

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Pulverization and Densification Behavior of YAG Powder Synthesized by PVA Polymer Solution Method

  • Im, Hyun-Ho;Lee, Sang-Jin
    • 한국재료학회지
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    • 제30권11호
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    • pp.573-580
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    • 2020
  • YAG (Yttrium Aluminum Garnet, Y3Al5O12) has excellent plasma resistance and recently has been used as an alternative to Y2O3 as a chamber coating material in the semiconductor process. However, due to the presence of an impurity phase and difficulties in synthesis and densification, many studies on YAG are being conducted. In this study, YAG powder is synthesized by an organic-inorganic complex solution synthesis method using PVA polymer. The PVA solution is added to the sol in which the metal nitrate salts are dissolved, and the precursor is calcined into a porous and soft YAG powder. By controlling the molecular weight and the amount of PVA polymer, the effect on the particle size and particle shape of the synthesized YAG powder is evaluated. The sintering behavior of the YAG powder compact according to PVA type and grinding time is studied through an examination of its microstructure. Single phase YAG is synthesized at relatively low temperature of 1,000 ℃ and can be pulverized to sub-micron size by ball milling. In addition, sintered YAG with a relative density of about 98 % is obtained by sintering at 1,650 ℃.

Proteotoxic Stress and Cell Lifespan Control

  • Cenci, Simone;Pengo, Niccolo;Sitia, Roberto
    • Molecules and Cells
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    • 제26권4호
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    • pp.323-328
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    • 2008
  • Eukaryotic cells continuously integrate intrinsic and extrinsic signals to adapt to the environment. When exposed to stressful conditions, cells activate compartment-specific adaptive responses. If these are insufficient, apoptosis ensues as an organismal defense line. The mechanisms that sense stress and set the transition from adaptive to maladaptive responses, activating apoptotic programs, are the subject of intense studies, also for their potential impact in cancer and degenerative disorders. In the former case, one would aim at lowering the threshold, in the latter instead to increase it. Protein synthesis, consuming energy for anabolic processes as well as for byproducts disposal, can be a significant source of stress, particularly when difficult-to-fold proteins are produced. Recent work from our and other laboratories on the differentiation of antibody secreting cells, revealed a regulatory circuit that integrates protein synthesis, secretion and degradation (proteostasis), into cell lifespan determination. The apoptotic elimination - after an industrious, yet short lifetime - of terminal immune effectors is crucial to maintain immune homeostasis. Linking proteostasis to cell death, this paradigm might prove useful for biotechnological purposes, and the design of novel anti-cancer therapies.

The Effect of Glucose and Glucose Transporter on Regulation of Lactation in Dairy Cow

  • Heo, Young-Tae;Park, Joung-Jun;Song, Hyuk
    • Reproductive and Developmental Biology
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    • 제39권4호
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    • pp.97-104
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    • 2015
  • Glucose is universal and essential fuel of energy metabolism and in the synthesis pathways of all mammalian cells. Glucose is the one of the major precursors of lactose synthesis using glycolysis result in producing milk fat and protein. During the milk fat synthesis, lipoprotein lipase (LPL) and CD36 are required for glucose uptake. Various morecules such as acyl-CoA synthetase 1 (ACSL1) activity of acetyl-CoA synthetase 2 (ACSS2), ACACA, FASN AGPAT6, GPAM, LPIN1 are closely related with milk fat synthesis. Additionally, glucose plays a major role for synthesizing lactose. Activations of lactose synthesize enzymes such as membranebound enzyme, beta-1,4-galactosyl transferase (B4GALT), glucose-6-phosphate dehydrogenase (G6PD) are changed by concentration of glucose in blood resulting change of amount of lactose production. Glucose transporters are a wide group of membrane proteins that facilitate the transport of glucose over a plasma membrane. There are 2 types of glucose transporters which consisted facilitative glucose transporters (GLUT); and sodium-dependent transport, mediated by the Na+/glucose cotransporters (SGLT). Among them, GLUT1, GLUT8, GLUT12, SGLT1, SGLT2 are main glucose transporters which involved in mammary gland development and milk synthesis. However, more studies are required for revealing clear mechanism and function of other unknown genes and transporters. Therefore, understanding of the mechanisms of glucose usage and its regulation in mammary gland is very essential for enhancing the glucose utilization in the mammary gland and improving dairy productivity and efficiency.