• 제목/요약/키워드: capillary density

검색결과 91건 처리시간 0.023초

세균성마름병에 대한 담배의 저항성검정 방법 (A Screening Method on Resistance of Tobacco Plants to Bacterial Wilt)

  • 이영근
    • 한국연초학회지
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    • 제24권1호
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    • pp.27-31
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    • 2002
  • Three kinds of inoculation methods, capillary, root cutting and dipping were compared for an efficient way to screening the resistant tobacco variety against bacterial wilt, Ralstonia solanacearum. The pricking a capillary tube contained the pathogenic bacterial suspension(10$^{7}$ cfu/$m\ell$) to an axillary bud of each tobacco plant showed different resistance well between varieties. The less period was required in inoculating work and in disease development for the inoculation method used with capillary tube than for two other inoculation methods tested also.

냉동기유가 모세관내의 냉매유량에 미치는 영향 (The Effects of Oil on Refrigerant Flow through Capillary Tubes)

  • 홍기수;황일남;민만기
    • 설비공학논문집
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    • 제12권9호
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    • pp.791-801
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    • 2000
  • An experimental study was conducted to analyze the effects of oil on refrigerant flow through adiabatic capillary tubes, and to develop a model for mass flow rates of refrigerant/oil mixture at various capillary tubes and flow conditions. Mass flow rates and the profiles of the pressures and temperatures along the capillary tubes was obtained with the oil concentration of R-22/SUNISO 4GS oil mixture at various test conditions. The flow trends as a function of geometry and flow conditions for pure refrigerant and refrigerant/oil mixture were similar in adiabatic capillary tubes. Mass flow rate of the refrigerant/oil mixture was less than that of pure refrigerant at the same test conditions.

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방사선조사에 따른 백서 악하선내 혈관 내피세포 미세구조의 조기변화 (EARLY IRRADIATION EFFECTS ON THE ULTRASTRUCTURE OF THE CAPILLARY ENDOTHELIAL CELL IN THE RAT SUBMANDIBULAR GLANDS)

  • 류정수;손정익;배용철;최갑식
    • 치과방사선
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    • 제25권1호
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    • pp.71-87
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    • 1995
  • The purpose of this study was to investigate the early irradiation changes on the ultrastructure of the capillary endothelial cell in the rat submandibular glands. For the study, 110 Sprague-Dawley strain male rats were singly irradiated to their neck regions with the doses of 2Gy, 5Gy, and 10Gy by 6MV X -irradiation, and sacrificed on the 3 hours, 6 hours, 12 hours, 1 day, 3 days, 7 days, and 14 days after irradiation. The authors observed the histologic and ultrastructural changes of the capillary endothelial cell using the light and electron microscopes. The results were as follows: I. In the light microscopic examination, the capillary dilation was observed on the 6 hours group and the capillary density was slightly increased on the 12 hours group after 2Gy and 5Gy irradiation. And luminal size and capillary density were decreased on the 3 days and the 7 days groups after irradiation, after then, they were recovered. But capillary density was still decreased on the 14 days group after 10Gy irradiation. 2. In the transmission electron microscopic examination, the mild proliferation of cytoplasmic process of the endothelial cell and reduction in luminal size were observed on the 3 hours group after irradiation. After then, endothelial swelling, marked proliferation of cytoplasmic process, thickened basal lamina, and numerous pinocytotic vesicles were observed after the 1 day group after irradiation. Thickened basal lamina and numerous pinocytotic vesicles were still observed until the 7 days group after irradiation. These changes were recovered to normal on the 14 days group after 2Gy and 5Gy irradiation, but not after 10Gy irradiation. 3. In the scanning electron microscopic examination, the dilation of conduits and constriction, and meandering were observed on the 1 day group after 10Gy irradiation. These changes were observed with increased coarseness of the surface of the vascular resin casting on the 3 days group after irradiation. 4. From the above results, endothelial swelling, proliferation of cytoplasmic process, and thickening of the basal lamina appeared before the 6 hours group after irradiation. And these changes may also induce the increase of the capillary number and luminal size, after then, capillary permeability was increased via the increase of the number of pinocytotic vesicles. The changes were observed earlier and more apparent with the increase of the irradiation doses under the dose of 10Gy irradiation.

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캐필러리 레오미터를 이용한 고분자의 PvT 측정 방법 (PvT measruement method of polymer using capillary rheometer)

  • 김선경;박재은
    • Design & Manufacturing
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    • 제14권3호
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    • pp.31-36
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    • 2020
  • In injection molding processes, the property of molten resin should be characterized accurately. Among several properties, the PvT state is the most important one, since it affects the shrinkage, warpage, molded weight, and the part density. Thus, the PvT data is crucial to the simulation of the injection molding process. This work shows how such a measurement can be performed for a semi-crystalline and amorphous polymers. The PvT measurement has been conducted using a capillary rheometer using a suitable accessory that blocks the capillary. The results have shown that the PvT data can be obtained using such a rheometer and then the PvT coefficients of the Tait equation can be reached.

방사선조사가 악하선 미세혈관과 내피세포에 미치는 영향에 관한 실험적 연구 (AN EXPERIMENTAL STUDY OF THE IRRADIATION EFFECTS ON THE CAPILLARY AND ENDOTHEILIAL CELL OF THE RAT SUBMANDIBULAR GLAND)

  • 유영아;손정익;최미;배용철;최갑식
    • 치과방사선
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    • 제24권1호
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    • pp.67-77
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    • 1994
  • The purpose of this study was to investigate the irradiatiion effects on the capillary and endothelial cell in the submandibular gland. Sprague-Dawley strain male rats were singly irradiated to their neck region with the dose of 5Gy by 6MV X-irradiation and sacrificed on the 6 hours, 12 hours, 1, 3, 7, and 14days after irradiation. The authors observed the histological changes of the capillary at H & E and PAS staining under a light microscope, and also observed the ultrastructural changes of the endothelial cell using a transmission electron microscope. The obtaining results were as follows: 1. In the light microscopic examination, the capillary density was slightly increased on the 1day after irradiation, and increased until the 7 days after irradiatiion. After then, capillary density was apparently decreased. 2. The reaction to PAS staining at acinar cells was decreased on the 6 hours after irradiation, and recovered on the 7days after irradiation. But reaction was decreased on the 14days after irradiation agan, after then, gradually recovered with days. 3. In the transmission electron microscopic examination, mild proliferation of cytoplasmic process of the endothelial cell and reduction in luminal size were observed just after irradiation. After then, nuclear degeneration, marked proliferation of cytoplasmic process, thickened basal lamina, and numerous cytoplasmic vesicles were observed on the 1day after irradiation. These changes were recovered to normal on the 14days after 5Gy group, but not with 10Gy irradiation group. And destruction of endothelial cell and loss of basal lamina were not observed in both groups. 4. From the above results, reduction in luminal size, proliferation of cytoplasmic process and thickening of basal lamina were observed as the irradiation effects on the capillary and endothelial cell of the submandibular gland. And also, these changes may induce increase in capillary number and endothelial permeability by means of increase of cytoplasmic vesicle formation. The changes appeared earlier and more prominent in 10Gy irradiated group than in 5Gy irradiated group.

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Impaired angiogenesis in the enalapril-treated neonatal rat kidney

  • Yim, Hyung Eun;Yoo, Kee Hwan;Bae, Eun Soo;Hong, Young Sook;Lee, Joo Won
    • Clinical and Experimental Pediatrics
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    • 제59권1호
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    • pp.8-15
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    • 2016
  • Purpose: Nephrogenesis is normally accompanied by a tightly regulated and efficient vascularization. We investigated the effect of angiotensin II inhibition on angiogenesis in the developing rat kidney. Methods: Newborn rat pups were treated with enalapril (30 mg/kg/day) or vehicle (control) for 7 days after birth. Renal histological changes were checked using Hematoxylin & Eosin staining. We also investigated the intrarenal expression of vascular endothelial growth factor (VEGF)-A, VEGF receptor 1 (VEGFR1), VEGFR2, platelet-derived growth factor (PDGF)-B, and PDGF receptor-${\beta}$ with Western blotting and immunohistochemical staining at postnatal day 8. Expression of the endothelial cell marker CD31 was examined to determine glomerular and peritubular capillary density. Results: Enalapril-treated rat kidneys showed disrupted tubules and vessels when compared with the control rat kidneys. In the enalapril-treated group, intrarenal VEGF-A protein expression was significantly higher, whereas VEGFR1 protein expression was lower than that in the control group (P<0.05). The expression of VEGFR2, PDGF-B, and PDGF receptor-${\beta}$ was not different between the 2 groups. The increased capillary CD31 expression on the western blots of enalapril-treated rat kidneys indicated that the total endothelial cell protein level was increased, while the cortical capillary density, assessed using CD31 immunohistochemical staining, was decreased. Conclusion: Impaired VEGF-VEGFR signaling and altered capillary repair may play a role in the deterioration of the kidney vasculature after blocking of angiotensin II during renal development.

Measurement of Electron Temperature and Number Density and Their Effects on Reactive Species Formation in a DC Underwater Capillary Discharge

  • Ahmed, Muhammad Waqar;Rahman, Md. Shahinur;Choi, Sooseok;Shaislamov, Ulugbek;Yang, Jong-Keun;Suresh, Rai;Lee, Heon-Ju
    • Applied Science and Convergence Technology
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    • 제26권5호
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    • pp.118-128
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    • 2017
  • The scope of this work is to determine and compare the effect of electron temperature ($T_e$) and number density ($N_e$) on the yield rate and concentration of reactive chemical species ($^{\bullet}OH$, $H_2O_2$ and $O_3$) in an argon, air and oxygen injected negative DC (0-4 kV) capillary discharge with water flow(0.1 L/min). The discharge was created between tungsten pin-to pin electrodes (${\Phi}=0.5mm$) separated by a variable distance (1-2 mm) in a quartz capillary tube (2 mm inner diameter, 4 mm outer diameter), with various gas injection rates (100-800 sccm). Optical emission spectroscopy (OES) of the hydrogen Balmer lines was carried out to investigate the line shapes and intensities as functions of the discharge parameters such as the type of gas, gas injection rate and inter electrode gap distances. The intensity ratio method was used to calculate $T_e$ and Stark broadening of Balmer ${\beta}$ lines was adopted to determine $N_e$. The effects of $T_e$ and $N_e$ on the reactive chemical species formation were evaluated and presented. The enhancement in yield rate of reactive chemical species was revealed at the higher electron temperature, higher gas injection rates, higher discharge power and larger inter-electrode gap. The discharge with oxygen injection was the most effective one for increasing the reactive chemical species concentration. The formation of reactive chemical species was shown more directly related to $T_e$ than $N_e$ in a flowing water gas injected negative DC capillary discharge.

지료조성에 따른 종이의 사이징 특성 (The Influence of Paper Stock Type on Characteristics of Sizing)

  • 정상진;김봉용
    • 펄프종이기술
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    • 제37권2호
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    • pp.11-20
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    • 2005
  • This study was carried out to investigate the influence of paper stock type and heat treatment on sizing effect. Various types of pulps were used to make handsheets sized internally with AKD(alkyl ketene dimer) and externally with CMC(carboxyl methyl cellulose). Most of the handsheets were treated with heat by dry oven $(100^{\circ}C,\;30min)$ to evaluate the effect of heat treatment on sizing development. Internal sizing development of newsprint was very bad, but the effect of heat treatment was much higher than those of NBKP, BCTMP. In case of surface sizing, newsprint was more effective compared to the other pulps. Considering above mentioned results, it seems that internal sizing slows down water into paper by molecular diffusion much more than capillary penetration, but surface sizing slows down capillary penetration. With regard to density, a higher thickness sheets showed high heat treatment effect on sizing, therefore it assumed that heat treatment effect on sizing had very close relationship with sheet density.

규칙적인 지구성운동이 고혈압쥐 골격근의 혈관생성과 VEGF 발현의 증가를 통한 혈압감소에 미치는 효과 (Regular Endurance Exercise Decreases Blood Pressure via Enhancement of Angiogenesis and VEGF Expression in Spontaneously Hypertensive Rats)

  • 이위;박희근;이영란;장학영;추성호;이영화;감력;전종귀;이왕록;이상기
    • 생명과학회지
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    • 제22권5호
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    • pp.665-670
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    • 2012
  • 이 연구는 자연발생고혈압쥐(SHR)의 혈압, 골격근에서의 혈관생성 및 혈관내피세포성장인자 발현(VEGF)에 미치는 지구성운동의 효과를 조사하였다. 5주령 SHR와 WKY는 무작위로 정상혈압군(WKY, Wistar-Kyoto rat, n=9), 고혈압통제군(SHR-C, SHR Control, n=9) 및 고혈압운동군(SHR-E, SHR Exercise, n=9)으로 각각 분류하였고, 지구성운동은 트레드밀을 이용하였다(12-20 m/min, 0% grade, 60 min/day, 5 days/wk, 16 wk). 수축기혈압은 지구성운동에 의해 효과적으로 감소되었다(SHR-E vs. SHR-C, $p$ <0.05). 골격근의 모세혈관밀도와 VEGF 단백발현은 고혈압통제군(SHR-C)이 정상혈압군(WKY)보다 모두 감소되었으나, 지구성운동(SHR-E)이 고혈압통제군(SHR-C)에 비해 모두 증가되었다. 이러한 결과들은 지구력운동 트레이닝이 SHR 골격근의 VEGF 단백발현의 증가를 통해 모세혈관밀도를 향상시키고, 이러한 모세혈관밀도의 향상이 SHR의 혈압상승을 억제할 수 있다는 것을 의미한다.

사철쑥 (Artemisia Capillaris Thunberg)이 흰쥐 혈액 및 간지질 대사에 미치는 영향 (Effects of Artemisia Capillaris Thunberg on the Plasma and Liver Lipid Metabolism in Rats)

  • 이형자;황은희
    • Journal of Nutrition and Health
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    • 제35권4호
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    • pp.421-430
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    • 2002
  • 사철쑥 (Artemisia capitlaris Thunberg)으로 성인병의 예방목적으로 흰쥐 (Sprague-Dawley rats)의 혈액 및 간지질 대사에 미치는 영향에 대한 효과를 알아보았다. 1) 사료이용효율은 L, LM, LP군에서 높았다 (p < 0.01). 혈청의 콜레스테롤 농도, 동 맥 경화지수 (p <0.01), 중성지질 (p < 0.01)은 L, LM, LP군에서 높았지만, 사철쑥 분말 첨가에 의해 HDL-콜레스테롤과 HTR를 증가시켰다 (p < 0.01). 2) 혈청 및 간 조직의 과산화지질은 C군에 비하여 L군이 유의적으로 많았으며, 사철쑥 첨가시 감소하였다 (p < 0.05). 3) 간 조직의 지방침착은 L군에서 지방양성구의 크기와 분포가 두드러지게 높았고. LM군, LP길군에서는 감소하였다. 이상의 결과는 사철쑥은 혈액 및 간의 지질조성 및 지질 대사에 바람직한 효과를 갖는 것으로 보인다. 이는 사철쑥이 성인병예방에 유용한 기능성 식품으로서 가치가 있을 것으로 사료된다.