• 제목/요약/키워드: PH type

검색결과 183건 처리시간 0.029초

Marked Difference in Solvation Effects and Mechanism between Solvolyses of Substituted Acetylchloride with Alkyl Groups and with Aromatic Rigns in Aqueous Fluorinated Alcohol and in 2,2,2-Trifluoroethanol-Ethanol Solvent Systems

  • Oh, Yung-Hee;Jang, Gyeong-Gu;Lim, Gyi-Taek;Ryu, Zoon-Ha
    • Bulletin of the Korean Chemical Society
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    • 제23권8호
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    • pp.1089-1096
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    • 2002
  • Solvolyses rate constants of trimethylacetyl chloride (2), isobutyryl chloride (3), diphenylacetyl chloride (4) and p-methoxyphenylacetyl chloride (5) in 2,2,2-trifluoroethanol (TFE)-water, 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)-water and TFE-et hanol solvent systems at $10^{\circ}C$ are determined by a conductimetric method. Kinetic solvent isotope effects (KSIE) are reported from additional kinetic data for methanolyses of various substituted acetylchlorides in methanol According to the results of those reactions analyzed in terms of rate-rate profiles,extended Grunwald-Winstein type correlations, application of a third order reaction model based a general base catalyzed (GBC) and KSIE values. Regardless of the kind of neighboring groups (CH3- or Ph-groups) of reaction center, for aqueous fluorinated alcohol systems, solvolyses of 2, 3, 4, and 5 were exposed to the reaction with the same mechanism (a loose SN2 type mechanism by electrophilic solvation) controlled by a similarity of solvation of the transition sate (TS). Whereas, for TFE-ethanol solvent systems, the reactivity depended on whether substituted acetyl chloride have aromatic rings (Ph-) or alkyl groups (CH3-); the solvations by the predominant stoichiometric effect (third order reaction mechanism by GBC and/or by push-pull type) for Ph- groups (4 and 5) and the same solvation effects as those shown in TFE-water solvent systems for CH3- groups (2 and 3) were exhibited Such phenomena can be interpreted as having relevance to the inductive effect ( $\sigmaI)$ of substituted groups; the plot of log (KSIE) vs. ${\sigma}I$ parameter give an acceptable the linear correlation with r = 0.970 (slope = 0.44 $\pm$ 0.06, n = 5).

Gingival crevicular fluid CSF-1 and IL-34 levels in patients with stage III grade C periodontitis and uncontrolled type 2 diabetes mellitus

  • Ahu Dikilitas;Fatih Karaaslan;Sehrazat Evirgen;Abdullah Seckin Ertugrul
    • Journal of Periodontal and Implant Science
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    • 제52권6호
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    • pp.455-465
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    • 2022
  • Purpose: Periodontal diseases are inflammatory conditions that alter the host's response to microbial pathogens. Type 2 diabetes mellitus (T2DM) is a complex disease that affects the incidence and severity of periodontal diseases. This study investigated the gingival crevicular fluid (GCF) levels of colony-stimulating factor-1 (CSF-1) and interleukin-34 (IL-34) in patients with stage III grade C periodontitis (SIII-GC-P) and stage III grade C periodontitis with uncontrolled type 2 diabetes (SIII-GC-PD). Methods: In total, 72 individuals, including 24 periodontally healthy (PH), 24 SIII-GC-P, and 24 SIII-GC-PD patients, were recruited for this study. Periodontitis patients (stage III) had interdental attachment loss (AL) of 5 mm or more, probing depth (PD) of 6 mm or more, radiographic bone loss advancing to the middle or apical part of the root, and tooth loss (<5) due to periodontal disease. Radiographic bone loss in the teeth was also evaluated; grade C periodontitis was defined as a ratio of the percentage of root bone loss to age greater than 1.0. The plaque index (PI), gingival index (GI), presence of bleeding on probing (BOP), PD, and clinical AL were used for clinical periodontal assessments. GCF samples were obtained and analyzed using an enzyme-linked immunosorbent assay. Results: All clinical parameters-PD, AL, GI, BOP, and PI-were significantly higher in the SIII-GC-PD group than in the PH and SIII-GC-P groups for both the full mouth and each sampling site (P<0.05). The total IL-34 and CSF-1 levels were significantly higher in the SIII-GC-PD group than in the PH and SIII-GC-P groups (P<0.05), and there were significant differences between the periodontitis groups (P<0.05). Conclusions: These findings suggest that IL-34 and CSF-1 expression increases in patients with SIII-GC-PD. CSF-1 was associated with the inflammatory status of periodontal tissues and T2DM, while IL-34 was associated only with T2DM.

PIN形 非晶質 硅素 太陽電池의 製作 및 特性 (Fabrication and Characteristics of PIN Type Amorphous Silicon Solar Cell)

  • 박창배;오상광;마대영;김기완
    • 대한전자공학회논문지
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    • 제26권6호
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    • pp.30-37
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    • 1989
  • Silane($SiH_4$), methane($CH_4$), diborane(B_2H_6)그리고 phosphine($PH_3$)을 이용하여 rf글로방전분해법으로 PIN형 a-SiC:H/a-Si:H 이종접합 태양전지를 제작하였다. $SnO_2/ITO$층 형성치 태양전지의 효율은 ITO 투명전극만의 경우보다 1.5% 향상되었다. 제작조건은 P층의 경우 $CH_4/SiH_4$의 비를 5로 하고 두께는 $100{\AA}$이었다. I층은 P층위에 증착하였으나 진성이 아니고 N형에 가깝다. 이 I층을 진성으로 바꾸기 위해서 0.3ppm의 $B_2H_6$$SiH_4$에 혼합하여 5000${\AA}$증착했다. 또한 N층은 $PH_4/SiH_4$의 비를 $10^{-2}$로 하여 $400{\AA}$ 증착시켰다. 그 결과 입사강도가 15mW/$cm^2$일 때 개방전압 $V_{oc}=O'$단락전류밀도 $J_{sc=14.6mA/cm^2}$, 충진율 FF=58.2%, 그리고 효율 ${eta}=8.0%$를 나타내었다. 빛의 반사에 의한 손실을 감소시키기 위하여 $MgF_2$를 유리기판위에 도포하였다. 이에 의한 효율은 0.5% 향상되어 전체적인 효율은 8.5%였다.

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Effect of pH on the expression of RsMYB1 that regulates anthocyanin production in Petunia plants

  • Lee, Deuk Bum;Ai, Trinh Ngoc;Naing, Aung Htay;Kim, Chang Kil
    • Journal of Plant Biotechnology
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    • 제45권1호
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    • pp.30-35
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    • 2018
  • We established an in vitro system to investigate transcription levels of the RsMYB1 gene expressed in T2 20-day-old transgenic Petunia plants (three independent lines: PhRs1, PhRs2, and PhRs3), and the association between those transcription levels and anthocyanin production at various pH values (3.0 to 8.0) for a period of 10 days. All the lines treated with pH 5.0-7.0 exhibited increased anthocyanin content and delays in growth compared to the wild-type (WT) seedlings. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis confirmed that the enhancement of anthocyanin production in the transgenic lines was due to the upregulation of RsMYB1 transcription at various pH values. The results suggest that pH value can control expression of RsMYB1 which is associated with anthocyanin production.

A two-component sensor kinase (GacS) mediated signal transduction pathway involved in production of antifungal compounds in Pseudomonas chlororaphis O6.

  • Kang, Beom-Ryong;Lee, Jung-Hoon;Kim, Hyun-Jung;Cho, Baik-Ho;Kim, Young-Cheol
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.99.1-100
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    • 2003
  • E. intermedium Blocontrol activity of a P. chlororaphis rhizobacteium O6, depends to the synthesis of extracellular secondary metabolites and exoenzymes, thought to antagonize the pathogenicity of a variety of phytopathogenic fungi. The production of secondary metabolites and exoenzymes in O6, depends essentially on the GacS-mediated signal transduction pathway, which activates largely unknown signal transduction pathway. To exploit the GacS-mediated signal transdcution pathway involved in activation of ph genes that are necessary for biosynthesis of phenazine from P. chlororaphis O6, we cloned and sequenced the phz operon, rpoS gene encoding stationary specific sigma factor, ppx gene encoding polyphosphatase, and lon gene encoding ion protease. Expression of each gene in wild type and GacS mutant were analyzed by RT-PCR. Transcripts from rpoS, phzI enconing acylhomoserine lactone (AHL) synthase, and ph structural genes in the GacS mutant were reduced in each of these growth phases compared to the wild type. The GacS or Lon mutant was found to be deficient in the production of phenzines, exoenzymes, and the acylhomoserine lactone. These mutants were not complemented by ph operon and addition of exogenous AHL. These results indicate that the GacS global regulatory systems controls phenazine production at multiple levels. Future research will focus to identifying the GacS-mediated regulatory cascade involving in production of phenazine in P. chlororaphis.

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갈륨합금과 고동 아말감 합금의 물리적 성질 비교 (COMPARISON OF THE PHYSICAL PROPERTIES BETWEEN GALLIUM ALLOY AND HIGH COPPER AMALGAM ALLOYS)

  • 김현철;이희주;허복
    • Restorative Dentistry and Endodontics
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    • 제23권1호
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    • pp.278-287
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    • 1998
  • The purpose of this study was to compare the physical properties between high copper amalgam and gallium restorative material. In this study, the specimens for the 4 experimatal groups (Valiant, Valiant PhD, Gallium Alloy GF II. Gallium Alloy GF II triturated with some addition of alcohol) were prepared in the manner of which stated in ADA specification No.1 for amalgam alloy. And then, measured and compared the value of compressive strength. creep, and dimensional change during hardening of each sample. The results were as follows: 1. In the compressive strength, the Valiant-lathe cut type high copper amalgam-had the highest value of strength(p<0.05), and the Valiant PhD-admixed type high copper amalgam-showed the higher value of strength than the Gallium Alloy GF II(p<0.05) but had no significant difference with Gallium Alloy GF II triturated with some addition of alcohol(p>0.05). 2. In the creep. the Valiant PhD showed the highest value of creep (p<0.05), but there was no significant difference between Gallium Alloy GF II and Valiant(p>0.05). 3. In the dimensional change during hardening, no two groups were significantly different at the 0.050 level. 4. There was no significant difference between Gallium Alloy GF II and the same material which was triturated with some addition of alcohol(p>0.05).

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LOSS PROBABILITY IN THE PH/M/1/K QUEUE

  • Kim, Jeong-Sim
    • Journal of applied mathematics & informatics
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    • 제24권1_2호
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    • pp.529-534
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    • 2007
  • We obtain an explicit expression of the loss probability for the PR/M/1/K queue when the offered load is strictly less than one.

무엇이 중소기업의 개방형 혁신을 결정하는가? 전략-문화 혼합유형과 환경 역동성을 고려한 실증연구 (What Determines Open Innovation in SMEs? An Empirical Study Considering the Strategy-Culture Mixed Typology and Environmental Dynamism)

  • 권세인;양종곤
    • 융합정보논문지
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    • 제12권4호
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    • pp.345-353
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    • 2022
  • 본 연구는 전략-문화 혼합유형과 환경 역동성을 고려하여 중소기업의 개방형 혁신에 적합한 상황 및 유형을 실증적으로 규명하는 것을 목적으로 한다. 174개 중소기업을 대상으로 4개 집단으로 분류하여 분석한 결과는 다음과 같다. 첫째, 전략-문화가 일치하는 PD형은 내·외향형 혁신 모두 혁신성과에 긍정적 영향을 미치고 동적 기술환경에서 내향형 혁신을 통해 성과를 향상시켰다. 반대로 DH형은 내·외향형 혁신 모두 유의한 효과가 없었다. 둘째, 전략-문화가 불일치하는 PH형과 DD형은 외향형과 내향형 중 단일 혁신만 성과에 영향을 미쳤다. 한편, PH, DD, DH형은 환경 역동성에 따른 조절효과는 확인되지 않았다. 개방형 혁신을 지향하는 중소기업은 변화·혁신 지향형 전략과 창의·도전적 문화를 일치시킴으로써 혁신성과를 향상하도록 노력해야 한다.

Mettl14 mutation restrains liver regeneration by attenuating mitogens derived from non-parenchymal liver cells

  • Insook, Yang;Seung Yeon, Oh;Suin, Jang;Il Yong, Kim;You Me, Sung;Je Kyung, Seong
    • BMB Reports
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    • 제55권12호
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    • pp.633-638
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    • 2022
  • Liver regeneration is a well-known systemic homeostatic phenomenon. The N6-methyladenosine (m6A) modification pathway has been associated with liver regeneration and hepatocellular carcinoma. m6A methyltransferases, such as methyltransferase 3 (METTL3) and methyltransferase 14 (METTL14), are involved in the hepatocyte-specific-regenerative pathway. To illustrate the role of METTL14, secreted from non-parenchymal liver cells, in the initiation phase of liver regeneration, we performed 70% partial hepatectomy (PH) in Mettl14 heterozygous (HET) and wild-type (WT) mice. Next, we analyzed the ratio of liver weight to body weight and the expression of mitogenic stimulators derived from non-parenchymal liver cells. Furthermore, we evaluated the expression of cell cycle-related genes and the hepatocyte proliferation rate via MKI67-immunostaining. During regeneration after PH, the weight ratio was lower in Mettl14 HET mice compared to WT mice. The expressions of hepatocyte growth factor (HGF) and tumor necrosis factor (TNF)-α, mitogens derived from non-parenchymal liver cells that stimulate the cell cycle, as well as the expressions of cyclin B1 and D1, which regulate the cell cycle, and the number of MKI67-positive cells, which indicate proliferative hepatocyte in the late G1-M phase, were significantly reduced in Mettl14 HET mice 72 h after PH. Our findings demonstrate that global Mettl14 mutation may interrupt the homeostasis of liver regeneration after an acute injury like PH by restraining certain mitogens, such as HGF and TNF-α, derived from sinusoidal endothelial cells, stellate cells, and Kupffer cells. These results provide new insights into the role of METTL14 in the clinical treatment strategies of liver disease.