• 제목/요약/키워드: Cell volume decrease

검색결과 137건 처리시간 0.025초

수소전기차용 EPDM 고무의 충전재 입자 크기별 고압 수소 환경에서의 거동 연구 (Influence of Filler Particle Size on Behaviour of EPDM Rubber for Fuel Cell Vehicle Application under High-Pressure Hydrogen Environment)

  • 김기정;전형렬;강영임;김완진;염지웅;최성준;조성민
    • 한국수소및신에너지학회논문집
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    • 제31권5호
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    • pp.453-458
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    • 2020
  • In this study, ethylene-propylene-diene monomer (EPDM) rubbers reinforced with various particle size of carbon black were prepared and tested. We followed recently published CSA/ANSI CHMC2 standard "the test methods for evaluating material compatibility in compressed hydrogen applications-polyemr". Measurement of change in hardness, tensile strength and volume were performed after exposure to maximum operating pressure, 87.5 MPa, for 168 hours (1 week). Once EPDM was exposed to high-pressure hydrogen, the samples experience volume increase and degradation of the physical properties. Also, after the dissolved hydrogen was fully eliminated from the specimens, the hardness and the tensile properties were not recovered. The rubber reinforced with smaller sizes of carbon black particles showed less volume expansion and decrease of physical properties. As a result, smaller particle size of carbon black filler led to more resistance to high-pressure hydrogen.

Comparison of irradiated and non-irradiated acellular dermal matrices in breast reconstruction under radiotherapy

  • Woo, Soo Jin;Ha, Jeong Hyun;Jin, Ung Sik
    • Archives of Plastic Surgery
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    • 제48권1호
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    • pp.33-43
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    • 2021
  • Background Acellular dermal matrices (ADMs) have become an essential material for implant-based breast reconstruction. No previous studies have evaluated the effects of sterility of ADM under conditions of radiation. This study compared sterile (irradiated) and aseptic (non-irradiated) ADMs to determine which would better endure radiotherapy. Methods Eighteen male Balb/C mice were assigned to the control group with no irradiation (group 1) or one of two other groups with a radiation intensity of 10 Gy (group 2) or 20 Gy (group 3). Both sterile and aseptic ADMs were inserted into the back of each mouse. The residual volume of the ADM (measured using three-dimensional photography), cell incorporation, α-smooth muscle actin expression, and connective tissue growth factor expression were evaluated. The thickness and CD3 expression of the skin were measured 4 and 8 weeks after radiation. Results In groups 2 and 3, irradiated ADMs had a significantly larger residual volume than the non-irradiated ADMs after 8 weeks (P<0.05). No significant differences were found in cell incorporation and the amount of fibrosis between irradiated and non-irradiated ADMs. The skin was significantly thicker in the non-irradiated ADMs than in the irradiated ADMs in group 3 (P<0.05). CD3 staining showed significantly fewer inflammatory cells in the skin of irradiated ADMs than in non-irradiated ADMs in all three groups after 4 and 8 weeks (P<0.05). Conclusions Under radiation exposure, irradiated ADMs were more durable, with less volume decrease and less deposition of collagen fibers and inflammatory reactions in the skin than in non-irradiated ADMs.

Antitumor Activity and Antioxidant Role of Ichnocarpus frutescens Against Ehrlich Ascites Carcinoma in Swiss Albino Mice

  • Dash, Deepak K;Nayak, Siva S;Samanta, Soma;Ghosh, Tirtha;Jha, Tarun;Maiti, Bhim C;Maity, Tapan K
    • Natural Product Sciences
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    • 제13권1호
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    • pp.54-60
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    • 2007
  • The plant Ichnocarpus frutescens (Linn) R.Br. (Family-Apocynaceae) has been indicated for the treatment of various diseases, one amongst it is cancer. The purpose of this study was to investigate experimentally the possible antitumor activity and antioxidant role of Ichnocarpus frutescens in the mice transplanted with Ehrlich ascites carcinoma (EAC). The chloroform and methanol extract of whole plant of Ichnocarpus frutescens (CEIF and MEIF) were administered intraperitoneally at the dose of 150 mg/kg and 300 mg/kg, body weight per day for 7 days after 24 h of tumor inoculation in mice. Treatment with CEIF at the dose of 150 mg/kg and 300 mg/kg remarkably decreased the tumor volume, packed cell volume, viable cell count and increased the nonviable cell count of EAC tumor bearing mice when compared to e effect of MEIF at 150 mg/kg and 300 mg/kg. Further the EAC mice treated with CEIF and MEIF showed significant decrease in the level of lipid peroxidation and significant increase in the level of antioxidant enzymes such as glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT), however the decreasing and increasing capacity of CEIF was less in both doses as compared to MEIF. Based on these results, it can be concluded that the chloroform and methanol extact of Ichnocarpus frutescens exhibit significant antitumor and antioxidant activity in EAC bearing mice.

The Influence of Microinjection of Foreign Gene into the Pronucleus of Fertilized Egg on the Preimplantation Development, Cell Number and Diameter of Rabbit Embryos

  • Makarevich, A.V.;Chrenek, P.;Fl’ak, P.
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권2호
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    • pp.171-175
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    • 2006
  • The aim of this in vitro study was to test the effect of microinjection (Mi) of foreign gene into the rabbit egg pronucleus and epidermal growth factor (EGF) addition on the blastocyst rate, the cell number and the diameter of embryos, and to determine possible relationships between embryo cell number and embryo diameter. Blastocyst rate was significantly decreased in gene- Mi (G-Mi/E0) group (63.1%) comparing to intact ones (83.5%, $p_1$<0.05). The addition of EGF at 20ng/ml (G-Mi/E20) or 200 ng/ml (GMi/ E200) to gene-Mi embryos did not affect blastocyst rate (65.6 and 55.2% resp.). As a control for Mi, the eggs were microinjected with the same volume of phosphate-buffered solution (PBS-Mi) instead of the gene construct solution. Cell numbers and embryo diameters were measured from embryo images obtained on confocal laser scanning microscope. Bonferroni-modified LSD test showed that the embryo cell number in PBS-Mi group was significantly lower ($p_1$<0.05) and in gene-Mi group was tended to decrease compared with intact embryos. Embryo diameter was not different among experimental groups. No effect of EGF given at any doses both on the cell number and embryo diameter was found. A positive correlation between cell number and embryo diameter was observed in all groups of embryos. Since embryo diameter was not changed under the influence of Mi or EGF addition in this study, this seems to be more conservative characteristics of the embryo morphology. These results suggest that the pronuclear microinjection compromises developmental potential of embryos, decreasing blastocyst rate and embryo cell number, whilst embryo diameter is not affected. No effects of EGF on studied parameters were confirmed. Declined quality of Mi-derived embryos is caused by the microinjection procedure itself, rather than by the gene construct used.

Buongiorno의 비균질 모델을 사용한 나노유체의 층류 자연대류 해석 (COMPUTATION OF LAMINAR NATURAL CONVECTION OF NANOFLUID USING BUONGIORNO'S NONHOMOGENEOUS MODEL)

  • 최석기;김성오;이태호
    • 한국전산유체공학회지
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    • 제18권4호
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    • pp.25-34
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    • 2013
  • A numerical study of a laminar natural convection of the CuO-water nanofluid in a square cavity using the Buongiorno's nonhomogeneous model is presented. All the governing equations including the volume fraction equation are discretized on a cell-centered, non-uniform grid employing the finite-volume method with a primitive variable formulation. Calculations are performed over a range of Rayleigh numbers and volume fractions of the nanopartile. From the computed results, it is shown that both the homogeneous and nonhomogeneous models predict the deterioration of the natural convection heat transfer well with an increase of the volume fraction of nanoparticle at the same Rayleigh number, which was observed in the previous experimental studies. It is also shown that the differences in the computed results of the average Nusselt number at the wall between the homogeneous and nonhomogeneous models are very small, and this indicates that the slip mechanism of the Brown diffusion and thermophoresis effects are negligible in the laminar natural convection of the nanofluid. The degradation of the heat transfer with an increase of the volume fraction of the nanoparticle in the natural convection of nanofluid is due to the increase of the viscosity and the decrease of the thermal expansion coefficient and the specific heat. It is clarified in the present study that the previous controversies between the numerical and experimental studies are owing to the different definitions of the Nusselt number.

불균형식이(不均衡食餌)에 의(依)한 백서체내(白鼠體內) Homeostasis에 대(對)한 연구(硏究) (A Study on Homeostasis in Albino Rats by Feeding on Imbalanced Protein Diet)

  • 류총근
    • Journal of Nutrition and Health
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    • 제7권2호
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    • pp.37-51
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    • 1974
  • This Study was carried out to observe the effect of nutritional condition on the change of protein metabolism in the animal body by feeding on imbalanced protein diet. A total 242 growing male albino rats, weighing $115{\sim}120$ gm, were used for the experimental animals. The rats were fed on the standard diet(st), protein flee diet(pf) and imbalanced protein diet(ib) for twelve weeks respectively. Hemoglobin, packed cell volume in blood, and total nitrogen, amino acid nitrogen, urea-nitrogen, creatinine, transaminases(GPT, GOT) in liver and serum, and total nitrogen in small intestine, and total nitrogen, urea-nitrogen In small intestine, and total nitrogen, urea-nitrogen, creatinine, urea-nitrogen/creatinine ratio in urine were measured. The results obtained are as follows; 1. The gained body weight were lower in pf group and ib group than those of st group. The gained body weight fed for 12 weeks, were 80% lower in pf group than those of st group, and the body weight of pf group for $50{\sim}75$ days feeding were $40{\sim}60%$ decreased, compared with the stating weight, and then all of them died. 2. The change of the brain, liver, kidney, spleen and small intestine by feeding on imbalanced diet for 12 weeks were no remarkable difference with the starting weight, but those of protein free diet group were half or more decrease and those were significantly lower in spleen and small intestine especially than the other organ 3. The contents of hemoglobin in pf group for 8 weeks feeding, and the packed cell volume in pf group for 8 weeks feeding and in ib group for 12 weeks feeding were decreased. but those of the other feeding group were almost same value. 4. The total nitrogen in the liver, small intestine and serum of each diet group were no remarkable difference respectively. The contents of amino acid nitrogen in pf group for 2 and 6 weeks feeding were increased. 5. On transaminases: a) The cycle of increase and decrease of GPT activities were come periodically and the interval of cycle were fast in the early stage of feeding and slow there-after. b) The GPT activities were decreased gradually in pf group after feeding and those were increased in ib group for 6 weeks feeding but decreased there-after. The frequency of cycle were more GPT than GOT and specially those of GPT in early stage of feeding were two or three times while GOT was one. c) The interval of increase and decrease in GOT and amino acid nitrogen cycle were similar tendency. 6. The contents of total nitrogen, creatinine and urea-nitrogen of pf group in urine were decreased very sharply from sharting feeding to one week but increased dully from six weeks to eight weeks feeding. The contents of urea-nitrogen of ib group were increased dully by feeding on ten weeks but decreased by feeding on twelve weeks. From the above results, it is concluded that the trend of the metabolic change is maintained equally by homeostatic mechanism using the endogenous protein source during a certain period by imbalanced protein diet feeding. The homeostatic mechanism is come peridically, very fast in early stage of feeing and than slow there-after.

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SBY-III이 비만 및 비만 후 식이조절 흰쥐에 미치는 영향 (Anti-obesity Effects of SBY-III in High Fat Diet-Fed Obese Rats Continued by High Fat Diet and Regulated by Normal Diet)

  • 우경하;정석희;이종수;김성수;신현대
    • 한방재활의학과학회지
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    • 제15권2호
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    • pp.117-117
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    • 2005
  • Objectives : This experimental study was designed to investigate the effect of SBY-III extract on the weight, cell size of epididymal fat-pad, fat accumulation area in liver, serum lipid level and UCP1 mRNA in brown adipose tissue of high fat diet-fed obese rats continued by high fat diet and regulated by normal Diet. Methods : The body weight gain, weight of the internal organs(epididymis, liver, brown adipose tissue), insulin, triglyceride, total cholesterol, total lopod, free fatty acid, expression of UCP1 mRNA were measured in high fat diet-fed obese rats continued by high fat diet and regulated by normal diet. The experimental study are divided into exp-I and exp-II. Each study was administered normal diet, high fat diet and SBY-III according to each situation. Normal group is normal diet for 8 weeks. Exp-I are divided into control group(high fat diet for 8 weeks) and sample group(high fat diet for 8 weeks and SBY-III for last 2 weeks). Exp-II are divided into control group(high fat diet for 6 weeks and normal diet for 2 weeks) and sample group(high fat diet for 6 weeks and normal diet with SBY-III for 2 weeks). These were then compared mutually. Results : 1. Irrespective of diet control, sample group taken SBY-III showed the more effective decrease of weight gain than control group and diet control-fed sample group with SBY-III showed the more effective decrease of weight loss including weight gain than control group. 2. Irrespective of diet control, sample group taken SBY-III showed the more effective decrease cell size of epididymal fat-pad, fat accumulation area in liver than control group. 3. Non diet control-fed sample group taken SBY-III showed the more effective decrease of serum triglyceride, total lipid, free fatty acid than control group and diet control-fed sample group taken SBY-III showed the decrease of serum triglyceride, free fatty acid than control group. 4. Only diet control-fed sample group taken SBY-III showed the decrease of UCP1 volume. Conclusions : These results shows that SBY-III has effects on anti-obesity, especially keeping pace with diet control.

십육미유기음(十六味流氣飮)의 면역활성(免疫活性)에 의한 유방암(乳房癌) 세포 성장억제효과(成長抑制效果) (Shipyeukmiyeugi-eum Extracts Suppressed Tumor Growth through Immunomodulatory Effects on MCF-7)

  • 정연철;박영선;김동철
    • 대한한방부인과학회지
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    • 제25권3호
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    • pp.40-60
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    • 2012
  • Objectives: The object of this study was to observe antitumor, anticachexia and immunomodulatory effects of Shipyeukmiyeugi-eum(SYM) on human breast cancer cell, MCF-7, xenograft Balb/c nu-nu nude mice. Methods: Three different dosages of SYM-125, 250 and 500 mg/kg were orally administered once a day for 28 days from 11 days after tumor cell inoculation, and the changes on the body weights, tumor volume and weights, weights of spleen and popliteal lymph node and epididymal fat, serum IL-6 and IFN-${\gamma}$ levels, NK cell and peritoneal macrophage activities, splenic TNF-${\alpha}$, IL-$1{\beta}$ and IL-10 contents were observed. In addition, histopathological observations of apoptotic cell, spleen, popliteal lymph node and cervical brown adipose were also detected. The results were compared with a potent cytotoxic estrogen receptor antagonist, Tamoxifen 20 mg/kg treated mice. Results: Tumor volumes and weights were decreased without cytotoxic effects on the both MCF-7 and MCF-10A cells as results of all three different dosages of SYM treatment. And weights of body, spleen, popliteal lymph node, epididymal fat, serum IFN-${\gamma}$, NK cell, peritoneal macrophage activities, splenic TNF-${\alpha}$, IL-$1{\beta}$ and IL-10 contents were increased with decrease of serum IL-6. At histopathological observations, apoptotic tumor cells, spleen, popliteal lymph node and cervical brown adipose tissue were increased. That means tumor-related immunosuppress and cachexia were markedly inhibited by SYM treatment as compared with tumor-bearing mice. On the other hand, Tamoxifen showed marked cytotoxic effects against MCF-7 and MCF-10A, decreases of tumor volume and weights, and increases of apoptotic tumor cells and related decreases of tumor cell volumes, but tamoxifen markedly deteriorated the tumor-related immune-suppress and cachexia. Conclusions: The results obtained in this study suggest that SYM showed favorable anticancer effects and anticachexic effects on the MCF-7 cell xenograft through immunomodulatory effects. SYM did not induce any cytotoxic effects against both normal and cancer cells.

청국장 메탄올 추출물이 T98G 세포와 허혈성 뇌졸중 백서에 미치는 영향 (The Effects of Methanol Extract from Cheonggukjang in T98G Cells and Early Stage of Focal Ischemia Rodent Models)

  • 한경훈;김도희;송관영;이석원;한성희
    • 한국식품영양학회지
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    • 제28권6호
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    • pp.965-972
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    • 2015
  • This study was conducted to evaluate the neuroprotective effects of Cheonggukjang extract in in-vitro and in-vivo models. T98G-human glioblastoma cells were pretreated with various concentrations (1~10 mg/mL) of Cheonggukjang extract for 24 h and then exposed to $H_2O_2$ (1 mM) for 3 h. The neuroprotective effects of Cheonggukjang extract were measured using a CCK-8 kit assay, total antioxidant capacity (TAC) assay, reactive oxygen species (ROS) assay, and lactate dehydrogenase (LDH) release assay. The early stage focal ischemia rodent model was used as the in-vivo neurotoxicity model. Various concentrations (10~200 mg) of Cheonggukjang extract were administered to the animal models for 1 week. Peripheral blood was analyzed for glutathione peroxidase (GPx) expression by ELISA, and infarct volume reduction was analyzed by TTC staining. Cheonggukjang extract significantly (p<0.05) increased cell viability in T98G cells against $H_2O_2$ as well as against the induced neurotoxicity. Indeed, treatment with the Cheonggukjang extract induced a decrease in ROS and LDH expression and increased TAC significantly (p<0.05). However, Cheonggukjang extract did not induce a decrease in infarct volume or an increase in GPx expression in the in-vivo model. Despite the limitation in neuroprotection, Cheonggukjang extract may be useful for treating ROS injury.

사염화탄소와 갈락토사민 간장해 시의 오큐빈의 체내동태 차이 (Different Pharmacokinetics of Aucubin in Rats of Carbon tetrachloride and D-Galactosamine-induced Hepatic Failure)

  • 김미형;심창구;장일무
    • 약학회지
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    • 제37권4호
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    • pp.383-388
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    • 1993
  • Pharmacokinetics of aucubin, an irdoid glucoside, was compared in rats of experimental hepatic failure(EHF). EHF was induced by CCI$_{4}$ or D-galactosamine pretreatment. This work was designed to find out any differences in the pharmacokinetics of aucubin that may explain the different protective effect of aucubin on CCI$_{4}$- and galactosamine-induced EHF : aucubin reportedly protected CCI$_{4}$-inducing hepatotoxicity effectively, but did not for galactosamine-hepatotoxicity. EHF was induced by intraperitoneal injection Of CCI$_{4}$(0.9ml/kg) or galactosamine(250 mg/kg) to Wistar rats 24 hr before the pharmacokinetic study. The rats were fasted during the 24 hr. Aucubin was iv injected at a dose of 15 mg/kg and the plasma aucubin was assayed by HPLC. There were no significant differences in the pathophysiologies(body weight, liver weight, GTP, hematocrit, blood cell distrbution and plasma protein binding of aucubin) between the two EHF models except GOP which was significantly (p<0.05) higher in CCI$_{4}$-than in galactosamine-EHF. On the other hand, pharmacokinetics of aucubin such as total cleatance(CL$_{t}$), distribution volume at steady-state(Vd$_{ss}$), and mean residence time(MRT) differed significantly(p<0.05) between the models : for example, CL$_{t}$ was increased two fold by CCI$_{4}$, but not by galaclosamine ; Vd$_{ss}$, in galactosamine-EHF was higher than that in CCI$_{4}$-EHF ; MRT was decreased by CCI$_{4}$, but increased conversely by galactosamine. The increase of CL$_{t}$(and decrease of MRT) in rats of CCI$_{4}$-EHF was contrary to the general expectation for the hepatic failure : most of the hepatic failures have been known to decrease CL$_{t}$ of the administered drugs. Whether the difference in the pharmacokinetics is responsible for the different protective effect of aucubin against the two EHF models is of interest. However, much more studies on biliary excretion, urinary excretion, and hepatic uptake in cellular level should be preceded before any conclusions are made on the role of different pharmacokinetics on the different pharmacology of aucubin.

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