• Title/Summary/Keyword: $C_{max}$

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A Statistical Review on States Relating to Operation of Radiotherapy Equipments in Seoul National University Hospital (서울대학교병원의 방사선치료장비 운용 통계에 관한 고찰)

  • Park, Heung-Deuk;Kim, Wan-Sun;Ahn, Hee-Yong
    • The Journal of Korean Society for Radiation Therapy
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    • v.6 no.1
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    • pp.21-30
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    • 1994
  • To analyze the states of operation of radiotherapy facilities in the period from 1979 to 1992 and to get the base for efficient operation and maintenance of the radiotherapy facilities. Data on the records of annual number of patients operated by each facility; span of suspension of operation, the cost and span of repairing, and parts of oui-of-order in the period from 1979 to 1992 were analyzed. We made a comparative analysis of average annual number of patients, annual span of the suspension of operation, annual cost ratio of repair, span of repairing per break down, and total number of broken parts. We could get following annual number of patients(day), span of the suspension of span ($\%$)(day). annual cost ratio fo repair($\%$), span of repairing per break down(Min-Max, day), and number of broken parts from this analysis. 1. Cobalt unit (Picker C-9) : 10,389(43), 0.4(0.83) 0.07, 1hr-2, 3 2. Linac(Clinac 6/100) : 11,492(50), 4.0(9.57), 0.98, 1hr-30, 12 3. Linac(Clinac 18) : 9.115(44), 12.7(30.5), 3.54, 1hr-108. 41 4. Simulator(Picker Ther-X) : 2,017(9), 0.51(1.3), 0.24, 1hr-2, 7 5. RTP(Capentec Cap-plan) : 528(2), 0.4(0.93), - hrs, - The conclusion obtained from statistical analysis above are as follows. 1. The rate of operation of Cobalt unit($99.6\%$) was higher that of Linear Accelerators ($87.3\%$). The rates operation of Simulator and RTP computer were very close to that of Cobalt unit. 2. In order to raise up the working ratio of accelerator. it is desirable that we keep our engineer to learn a sufficient technical skill and the equipment agent to stock sufficient spare parts. 3. In order to maintain Linear Accelerator efficiently, it is desirable to have annually $2.3\%$ of the purchase price of equiment for repairing.

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Thermostable Sites and Catalytic Characterization of Xylanase XYNB of Aspergillus niger SCTCC 400264

  • Li, Xin Ran;Xu, Hui;Xie, Jie;Yi, Qiao Fu;Li, Wei;Qiao, Dai Rong;Cao, Yi;Cao, Yu
    • Journal of Microbiology and Biotechnology
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    • v.24 no.4
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    • pp.483-488
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    • 2014
  • In order to improve the expression of heat-resistant xylanase XYNB from Aspergillus niger SCTCC 400264, XynB has been cloned into Pichia pastoris secretary vector pPIC9K. The XynB production of recombinant P. pastoris was four times that of E. coli, and the $V_{max}$ and specific activity of XynB reached $2,547.7{\mu}mol/mg$ and 4,757 U/mg, respectively. XynB still had 74% residual enzyme activity after 30 min of heat treatment at $80^{\circ}C$. From the van der Waals force analysis of XYNB (ACN89393 and AAS67299), there is one more oxygen radical in AAS67299 in their catalytic site, indicating that the local cavity is much more free, and it is more optimal for substrate binding, affinity reaction, and proton transfer, etc, and eventually increasing enzyme activity. The H-bonds analysis of XYNB indicated that there are two more H-bonds in the 33rd Ser of XYNB (AAS67299) than in the 33rd Ala(ACN89393 ), and two H-bonds between Ser70 and Asp67.

Optimization of ${\beta}$-Glucosidase Production by a Strain of Stereum hirsutum and Its Application in Enzymatic Saccharification

  • Ramachandran, Priyadharshini;Nguyen, Ngoc-Phuong-Thao;Choi, Joon-Ho;Kang, Yun Chan;Jeya, Marimuthu;Lee, Jung-Kul
    • Journal of Microbiology and Biotechnology
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    • v.23 no.3
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    • pp.351-356
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    • 2013
  • A high ${\beta}$-glucosidase (BGL)-producing strain, Stereum hirsutum, was identified and isolated and showed a maximum BGL activity (10.4 U/ml) when cultured with Avicel and tryptone as the carbon and nitrogen sources, respectively. In comparison with other BGLs, BGL obtained from S. hirsutum showed a higher level of activity to cellobiose ($V_{max}$ = 172 U/mg, and $k_{cat}$ = 281/s). Under the optimum conditions (600 rpm, $30^{\circ}C$, and pH 6.0), the maximum BGL activity of 10.4 U/ml with the overall productivity of 74.5 U/l/h was observed. BGL production was scaled up from a laboratory scale (7-L fermenter) to a pilot scale (70-L fermenter). When S. hirsutum was cultured in fed-batch culture with rice straw as the carbon source in a 70-L fermenter, a comparable productivity of 78.6 U/l/h was obtained. Furthermore, S. hirsutum showed high levels of activity of other lignocellulases (cellobiohydrolase, endoglucanase, xylanase, and laccase) that are involved in the saccharification of biomasses. Application of S. hirsutum lignocellulases in the hydrolysis of Pinus densiflora and Catalpa ovata showed saccharification yields of 49.7% and 43.0%, respectively, which were higher than the yield obtained using commercial enzymes.

Light transmittance of CAD/CAM ceramics with different shades and thicknesses and microhardness of the underlying light-cured resin cement

  • Jafari, Zahra;Alaghehmand, Homayoon;Samani, Yasaman;Mahdian, Mina;Khafri, Soraya
    • Restorative Dentistry and Endodontics
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    • v.43 no.3
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    • pp.27.1-27.9
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    • 2018
  • Objectives: The aim of this in vitro study was to evaluate the effects of the thickness and shade of 3 types of computer-aided design/computer-aided manufacturing (CAD/CAM) materials. Materials and Methods: A total of 120 specimens of 2 shades (A1 and A3) and 2 thicknesses (1 and 2 mm) were fabricated using VITA Mark II (VM; VITA Zahnfabrik), IPS e.max CAD (IE; IvoclarVivadent), and VITA Suprinity (VS; VITA Zahnfabrik) (n = 10 per subgroup). The amount of light transmission through the ceramic specimens was measured by a radiometer (Optilux, Kerr). Light-cured resin cement samples (Choice 2, Bisco) were fabricated in a Teflon mold and activated through the various ceramics with different shades and thicknesses using an LED unit (Bluephase, IvoclarVivadent). In the control group, the resin cement sample was directly light-cured without any ceramic. Vickers microhardness indentations were made on the resin surfaces (KoopaPazhoohesh) after 24 hours of dark storage in a $37^{\circ}C$ incubator. Data were analyzed using analysis of variance followed by the Tukey post hoc test (${\alpha}=0.05$). Results: Ceramic thickness and shade had significant effects on light transmission and the microhardness of all specimens (p < 0.05). The mean values of light transmittance and microhardness of the resin cement in the VM group were significantly higher than those observed in the IE and VS groups. The lowest microhardness was observed in the VS group, due to the lowest level of light transmission (p < 0.05). Conclusion: Greater thickness and darker shades of the 3 types of CAD/CAM ceramics significantly decreased the microhardness of the underlying resin cement.

A prebiotic fiber increases the formation and subsequent absorption of compound K following oral administration of ginseng in rats

  • Kim, Kyung-Ah;Yoo, Hye Hyun;Gu, Wan;Yu, Dae-Hyung;Jin, Ming Ji;Choi, Hae-Lim;Yuan, Kathy;Guerin-Deremaux, Laetitia;Kim, Dong-Hyun
    • Journal of Ginseng Research
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    • v.39 no.2
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    • pp.183-187
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    • 2015
  • Background: Gut microflora play a crucial role in the biotransformation of ginsenosides to compound K (CK), which may affect the pharmacological effects of ginseng. Prebiotics, such as NUTRIOSE, could enhance the formation and consequent absorption of CK through the modulation of gut microbial metabolic activities. In this study, the effect of a prebiotic fiber (NUTRIOSE) on the pharmacokinetics of ginsenoside CK, a bioactive metabolite of ginsenosides, and its mechanism of action were investigated. Methods: Male Sprague-Dawley rats were given control or NUTRIOSE-containing diets (control diet + NUTRIOSE) for 2 wk, and ginseng extract or vehicle was then orally administered. Blood samples were collected to investigate the pharmacokinetics of CK using liquid chromatography-tandem mass spectrometry. Fecal activities that metabolize ginsenoside Rb1 to CK were assayed with fecal specimens or bacteria cultures. Results: When ginseng extract was orally administered to rats fed with 2.5%, 5%, or 10% NUTRIOSE containing diets, the maximum plasma concentration ($C_{max}$) and area under the plasma concentration-time curve values of CK significantly increased in a NUTRIOSE content-dependent manner. NUTRIOSE intake increased glycosidase activity and CK formation in rat intestinal contents. The CK-forming activities of intestinal microbiota cultured in vitro were significantly induced by NUTRIOSE. Conclusion: These results show that prebiotic diets, such as NUTRIOSE, may promote the metabolic conversion of ginsenosides to CK and the subsequent absorption of CK in the gastrointestinal tract and may potentiate the pharmacological effects of ginseng.

Changes of Germination Rate of Pulses Seed Germplasm after Long-term Conservation

  • Baek, Hyung-jin;Lee, Young-yi;Jung, Yeon-ju;Yoon, Mun-seop
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2018.04a
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    • pp.44-44
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    • 2018
  • The seeds of soybean (Glycine max), adzuki bean (Vigna angularis), mung bean (Vigna radiata), and kidney bean (Phaseolus vulgaris L.) were examined the germination rate after 10 years of long-term storage ($-18^{\circ}C$) conservation. For soybean seeds, 2,313 accessions were examined and germination rate of 1,082 accessions was decreased with below 15% of initial germination rate. For 227 accessions of soybean, germination rate was decreased with above 15% of initial germination rate after 10 years of long-term storage, which is needed to be rejuvenated. Germination rate of 589 accessions was increased and showed no change for 415 accessions after 10 years of long-term storage. For adzuki bean seeds, 2,058 accessions were examined and germination rate of 739 accessions was decreased with below 15% of initial germination rate. For 63 accessions of adzuki bean, germination rate was decreased with above 15% of initial germination rate after 10 years of long-term storage, which is needed to be rejuvenated. Germination rate of 535 accessions was increased and showed no change for 721 accessions after 10 years of long-term storage. For mung bean seeds, 438 accessions were examined and germination rate of 139 accessions was decreased with below 15% of initial germination rate. For 5 accessions of mung bean, germination rate was decreased with above 15% of initial germination rate after 10 years of long-term storage, which is needed to be rejuvenated. Germination rate of 155 accessions was increased and showed no change for 139 accessions after 10 years of long-term storage. For kdney bean seeds, 366 accessions were examined and germination rate of 7 accessions was decreased with below 15% of initial germination rate. For 65 accessions of kidney bean, germination rate was decreased with above 15% of initial germination rate after 10 years of long-term storage, which is needed to be rejuvenated. Germination rate of 201 accessions was increased and showed no change for 93 accessions after 10 years of long-term storage.

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Pharmacokinetics and Metabolism of Endothelin Receptor Antagonist: Contribution of Kidneys in the Overall In Vivo N-Demethylation

  • Chong, Sae-Ho;Obermeier, Mary;Humlherys, W.-Griffith
    • Archives of Pharmacal Research
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    • v.26 no.1
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    • pp.89-94
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    • 2003
  • In vivo clearance of BMS-182874 was primarily due to metabolism via stepwise N-demethylation. Despite in vivo clearance approached ca 50% of the total liver plasma flow, BMS-182874 was completely bioavailable after oral administration in rats. Saturable first-pass metabolism and the role of extrahepatic tissue were evaluated as possible reasons for complete oral bioavailability despite extensive metabolic clearance. Pharmacokinetic parameters were obtained after an intravenous and a range of oral doses of BMS-182874 in rats. Bile and urine were collected from bile-duct cannulated (BDC) rats and the in vivo metabolic pathways of BMS-182874 were evaluated. Pharmacokinetics of BMS-182874 were also compared in nephrectomized (renally impaired) vs. sham-operated control rats. Oral bioavailability of BMS-182874 averaged 100%, indicating that BMS-182874 was completely absorbed and the first-pass metabolism (liver or intestine) was negligible. The AUC and C/sub max/ values increased dose-proportionally, indicating kinetics were linear within the oral dose range of 13 to 290 mmole/kg. After intravenous administration of BMS-182874 to BDC rats, about 2% of intact BMS-182874 was recovered in excreta, indicating that BMS-182874 was cleared primarily via metabolism in vivo. The major metabolite circulating in plasma was the mono-N-desmethyl metabolite and the major metabolite recovered in excreta was the di-N-desmethyl metabolite. In vivo clearance of BMS-182874 was significantly reduced in nephrectomized rats. These observations suggest saturable first-pass metabolism is unlikely to be a mechanism for complete oral bioavailability of BMS-182874. Reduced clearance observed in the nephrectomized rats suggests that extrahepatic tissues (e.g., kidneys) may play an important role in the in vivo clearance of xenobiotics that are metabolized via N-demethylation.

Studios on the Host Range of Cucumber Mosaic Virus in Korea (한국에서의 오이모자익 바이러스의 기주범위에 관한 연구)

  • Chung B. J.;Park H. C.;Lee S. H.
    • Korean journal of applied entomology
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    • v.14 no.4 s.25
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    • pp.185-192
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    • 1975
  • Various plant species, as many as 145 species in 43 families, were tested for susceptibility to the ordinary strain of the cucumber nosaic virus for two years from 1973 to 1974. Inoculations were made by mechanical method using carborundum. Plants in 71 species belonging to 27 families were infected. Of these species, systemic mosaic developed on the new leaves of plants in 57 species belonging to 24 families. Twenty-four species of plants, previously not reported as hosts of the CMV, were found to be infected in this experiment. These are Stellaria aquatica, Achyrauthes japonica, Agerratum houstonianum, Centipeda minima, Gillardia pulchella, Henisteptalyrate, Ixeris dentata, Saussurea uchiyamana, Brassica campestris, Lepidiumapetalum, Lobelia chinensis, Chenopodium bryoniaefolium, Carex neofilipes, Acalypha austalis, Amphicarpaea edgeworthii, Lotus corniculatus var japonicus, Phaseolus angularis, Sedum aizoom var heterodontum, Mosla punctulata, Perilla frutescens var japonica, Teucrium japonicum,. Linum usitatissimum, Mazus japonicus, Verbena hybrida. Twenty-three species reported to be susceptible by previous workers, but negative results were obtained in our experiment with Allium cepa, Celosia cristat, Daucus carota var. sativa, Artemisia asiatica, Callistenphus chinensis, Erigeron canadensis, Helianthusannuus, Tagetes eracta, Impatiens balsamina, Raphanus sativus, Ipomea batatas, Glycine max, Phaseolus vulgaris, Lilium longifolium, Papaver gomniferum, Sorghum vulgare, Triticum aestivum, Zea mays, Rumex coreanus, Potulaca grandiflora.

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Expression and pH-dependence of the Photosystem II Subunit S from Arabidopsis thaliana

  • Jeong, Mi-Suk;Hwang, Eun-Young;Jin, Gyoung-Ean;Park, So-Young;Zulfugarov, Ismayil S.;Moon, Yong-Hwan;Lee, Choon-Hwan;Jang, Se-Bok
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1479-1484
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    • 2010
  • Photosynthesis uses light energy to drive the oxidation of water at an oxygen-evolving catalytic site within photosystem II (PSII). Chlorophyll binding by the photosystem II subunit S protein, PsbS, was found to be necessary for energy-dependent quenching (qE), the major energy-dependent component of non-photochemical quenching (NPQ) in Arabidopsis thaliana. It is proposed that PsbS acts as a trigger of the conformational change that leads to the establishment of nonphotochemical quenching. However, the exact structure and function of PsbS in PSII are still unknown. Here, we clone and express the recombinant PsbS gene from Arabidopsis thaliana in E. coli and purify the resulting homogeneous protein. We used various biochemical and biophysical techniques to elucidate PsbS structure and function, including circular dichroism (CD), fluorescence, and DSC. The protein shows optimal stability at $4^{\circ}C$ and pH 7.5. The CD spectra of PsbS show that the conformational changes of the protein were strongly dependent on pH conditions. The CD curve for PsbS at pH 10.5 curve had the deepest negative peak and the peak of PsbS at pH 4.5 was the least negative. The fluorescence emission spectrum of the purified PsbS protein was also measured, and the ${\lambda}_{max}$ was found to be at 328 nm. PsbS revealed some structural changes under varying temperature and oxygen gas condition.

V-Band Power Amplifier MMIC with Excellent Gain-Flatness (광대역의 우수한 이득평탄도를 갖는 V-밴드 전력증폭기 MMIC)

  • Chang, Woo-Jin;Ji, Hong-Gu;Lim, Jong-Won;Ahn, Ho-Kyun;Kim, Hae-Cheon;Oh, Seung-Hyueb
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.623-624
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    • 2006
  • In this paper, we introduce the design and fabrication of V-band power amplifier MMIC with excellent gain-flatness for IEEE 802.15.3c WPAN system. The V-band power amplifier was designed using ETRI' $0.12{\mu}m$ PHEMT process. The PHEMT shows a peak transconductance ($G_{m,peak}$) of 500 mS/mm, a threshold voltage of -1.2 V, and a drain saturation current of 49 mA for 2 fingers and $100{\mu}m$ total gate width (2f100) at $V_{ds}$=2 V. The RF characteristics of the PHEMT show a cutoff frequency, $f_T$, of 97 GHz, and a maximum oscillation frequency, $f_{max}$, of 166 GHz. The gains of the each stages of the amplifier were modified to have broadband characteristics of input/output matching for first and fourth stages and get more gains of edge regions of operating frequency range for second and third stages in order to make the gain-flatness of the amplifier excellently for wide band. The performances of the fabricated 60 GHz power amplifier MMIC are operating frequency of $56.25{\sim}62.25\;GHz$, bandwidth of 6 GHz, small signal gain ($S_{21}$) of $16.5{\sim}17.2\;dB$, gain flatness of 0.7 dB, an input reflection coefficient ($S_{11}$) of $-16{\sim}-9\;dB$, output reflection coefficient ($S_{22}$) of $-16{\sim}-4\;dB$ and output power ($P_{out}$) of 13 dBm. The chip size of the amplifier MMIC was $3.7{\times}1.4mm^2$.

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