• Biomolecules & Therapeutics
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• 제29권5호
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• pp.545-550
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• 2021

Chemotherapy-induced alopecia and hair loss can be stressful in patients with cancer. The hair grows back, but sometimes the hair tends to stay thin. Therefore, understanding mechanisms regulating hair regeneration may improve the management of chemotherapy-induced alopecia. Previous studies have revealed that chemotherapeutic agents induce a hair follicle vascular injury. As hair growth is associated with micro-vessel regeneration, we postulated that the stimulation of angiogenesis might enhance hair regeneration. In particular, mice treated with 5-fluorouracil (5-FU) showed delayed anagen initiation and reduced capillary density when compared with untreated controls, suggesting that the retardation of anagen initiation by 5-FU treatment may be attributed to the loss of perifollicular micro-vessels. We investigated whether the ETS transcription factor ETV2 (aka ER71), critical for vascular development and regeneration, can promote angiogenesis and hair regrowth in a 5-FU-induced alopecia mouse model. Tie2-Cre; Etv2 conditional knockout (CKO) mice, which lack Etv2 in endothelial cells, presented similar hair regrowth rates as the control mice after depilation. Following 5-FU treatment, Tie2-Cre; Etv2 CKO mice revealed a significant reduction in capillary density, anagen induction, and hair restoration when compared with controls. Mice receiving lentiviral Etv2 injection after 5-FU treatment showed significantly improved anagen induction and hair regrowth. Two-photon laser scanning microscopy revealed that enforced Etv2 expression restored normal vessel morphology after 5-FU mediated vessel injury. Our data suggest that vessel regeneration strategies may improve hair regrowth after chemotherapeutic treatment.

• Corrosion Science and Technology
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• 제3권2호
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• pp.54-58
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• 2004

Effects of texture on the electrochemical behaviors of single grains in polycrystalline zinc were investigated using a capillary-based micro-droplet cell. Pontiodynamic sweeps and capacity measurements were carried out in pH 9 borate buffer solution. The cyclic voltammograms and the capacity measurements on single grains with different crystallographic orientations in polycrystalline Zn showed a strong dependence of oxide growth on crystallographic grain orientation. The total charge consumed for oxide formation and the inverse capacity increased with an increase of surface packing density of grain. suggesting the oxide formation was greater on grains with higher surface packing density.

• Tribology and Lubricants
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• 제25권4호
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• pp.236-242
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• 2009

Oil viscosity is one of the important parameters for machinery condition monitoring. Basically, it is expressed as kinematic viscosity measured by capillary flow and dynamic or absolute viscosity measured by rotary shear viscometry. Recently, acoustic wave techniques appear in the market, measuring viscosity as the product of dynamic viscosity and density. For Newtonian fluids, knowledge of density allows conversion from one viscosity parameter to the other at a specific shear rate and temperature. In this work, oil samples with different chain lengths of viscosity index (VI) improvers and concentrations were examined by different viscometric techniques. Results showed that acoustic viscosity measurements give misleading results for oil samples with high molecular weight VI improvers and at low temperatures ${\leq}40^{\circ}C$.

• 대한기계학회논문집B
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• 제30권10호
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• pp.982-986
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• 2006

It is well known that the surface tension forces can make a particle denser than water float when the size of the particle is of the order of 1 mm. This is deeply related to the basic mechanism enabling small insects to wander around on the pond surface and also to a newly emerging technology of self-assembly using capillary forces. For the quantitative understanding of this effect, we experimentally study the maximum density of a cylinder that can float on water and how fast the cylinder sinks when the density exceeds the maximum value. We compare our experimental results with the theoretical prediction and find good agreement between them.

• 아시안잔디학회지
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• 제7권1호
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• pp.13-18
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• 1993

Much attention has been given recently to solve the environmental contamination in golf courses Changing to culture practice rather than chemical practice that depends on pesticides and fertilizers is a hot issue in golf courses or grasslands. Organic soil conditioners improve soil-plant envirormental conditions rich in physical properties. In this study, measuring systems to evaluate soil conditioning effects were set up for on-site purpose. After establishing the methodology for evaluating soil conditioner effects, 2 kinds of organic conditioners were rested for examination. The systems for the methodology included a set of simulating equipment for field capacity, an impact type soil column compactor, and an infiltration-percolation system. Test results using the systems showed bulk density and infiltration rate of mixed soil were decreased at highter rates of conditioner, but total porocities were increased. Increased porocities were most capillary pore space which has a positive effect on soil water potential. The systems and methodology in this study seem to have an efficiency to measure the effects of soil conditioner on site purpose.

• 한국세라믹학회지
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• 제31권11호
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• pp.1307-1314
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• 1994

The aim of this work is to show the way of manufacturing the SiC mechanical seal at the low temperature of 130$0^{\circ}C$ using clay and frit as source of secondary phase. $\alpha$-SiC and $\beta$-SiC powder which showed different distribution of particle were used as starting materials, i.e. average particle size of $\alpha$-SiC was larger than that of $\beta$-SiC. The mechanical and tribological properties of two groups of specimen, i.e. one contained mainly larger $\alpha$-SiC powder and the other mainly fine particle $\beta$-SiC, were measured. The specimen consisted of larger $\alpha$-SiC exhibited lower density flexural strength and wear resistance is comparison with these of sample containning mainly $\beta$-SiC . This difference could be originated from the dependence of capillary force on the particle size. For the larger SiC particle, the liquid phase may not fill the whole pores during sintering, due to low capillary force, whereas the liquid phase can infiltrate into the small ores surrounded small $\beta$-SiC particle. Thus, the course of high flexural strength and high wear resistance of specimen prepared using small particles can be explaced from the easy infiltration of liquid phase.

• Journal of Electrical Engineering and Technology
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• 제7권6호
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• pp.971-976
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• 2012

A 150 kJ compact capacitive pulsed power system (CCPPS) capable of delivering electrical energy into an electrothermal chemical (ETC) gun on a vehicle has been studied. The CCPPS provides pulsed electrical energy into a capillary plasma injector which generates plasma of tens of thousands $^{\circ}K$ in temperature and has a nonlinear resistance depending on the current. The design requirements of the CCPPS are as follows: the maximum power of 250 MW, the pulse width of about 0.6 ms, the volume of no more than 0.5 cubic meter, the efficiency of energy transfer over 80 % and the repetition rate of 4~5 times per minute. The constructed CCPPS is composed of four 37.5 kJ capacitor bank modules in parallel to make a trapezoid pulse shape and to satisfy the design requirements. Each module is designed to achieve high reliability, safety, efficiency and energy density to endure severe operating conditions. The results of the performance test on the CCPPS using a 120 mm ETC gun are described.

• Journal of Periodontal and Implant Science
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• 제23권1호
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• pp.16-26
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• 1993

In order to investigate the healing effect on inflammation and bone regeneration of low power density laser radiation in dogs, experimental periodontitis was made in dog mandibular 3rd, 4th premolars. All teeth were classified with four groups of two experimental group and control groups. The second group were irradiated on periodontitis site and the first group were control. The fourth group were irradiated on periodontitis site flap operation and the third group were flap control. Experimental groups were irradiated with GaAs low power density laser of pulse wave and continuous wave of 904nm every day by five days respectively and then control group and experimental groups were evaluated by histo-pathological study. The results were as follows : 1. Experimental periodontits site of dog were irradiated with GaAs low power laser results in reducing of pseudoepitheliomatous proliferation and inflammation at light microscope. 2. After irradiation with low power density laser, experimental groups were revealed that PDL forming activity were increased and newly formed collagen deposition were observed. 3. Low power density lsaer irradiation on experimental periodontits site after flap operation showed that decreasing of inflammation, reducing of osteoclast activity. Capillary proliferation, reduction of pseudoepitheliomatous proliferation. 4. After irradiation with low power density laser on flap experimental site, experimental groups were revealed that newly formed collagen in periodontal ligament and alveolar bone were detected on MT staining.

• 아시안잔디학회지
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• 제25권1호
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• pp.106-111
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• 2011

본 연구는 아메리카동애등애 사육과정에서 발생한 분변토(SFC)가 골프장의 토양개량제로서 사용가능성을 평가하기 위해 모래와 혼합비율별 물리화학성을 조사하고자 한다. 토양개량제의 혼합비율에 따라 상토의 물리화학성을 조사한 결과는 다음과 같다. SFC, compost 및 cocopeat는 pH와 EC에서 고도의 정의 상관성 (P<0.01)을 나타내어 토양개량제의 특성에 따라 상토의 토양화학성에 영향을 주었다. SFC와 compost의 혼합에 따른 토양물리성 변화에서 가장 중요한 요인은 모세관공극으로 총공극이나 수리전도도의 변화에 영향을 미쳤다. 토양개량제의 혼합비율에 따른 토양개선효과를 비교할 때, SFC는 모세관공극, 총공극 및 수리전도도에서, compost는 모세관공극, 비모세관공극, 총공극 및 수리전도도에서, cocopeat는 모세관공극과 비모세관공극에서 고도의 상판성을 나타내었다(P<0.05). 이들 결과를 통해 토양개량제의 종류와 특성 및 혼합비율이 USGA 상토의 근권층 개량과 토양 이화학성에 영향을 미치고 있음을 알 수 있으며, 본 실험조건에서는 SFC는 상토의 공극과 수리전도도의 개선효과를 보였다.

• Journal of Nutrition and Health
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• 제11권1호
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• pp.33-37
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• 1978

The effect of heating time (0 to 30 hours at $180{\pm}5^{\circ}C$) on the change of flow properties, fatty acid compositions and some other characteristics such as acid value, iodine value, peroxide value and density of purified edible rice bran oil were observed. flow properties were measured with Maron-Belner type capillary viscometer. Newtonian motion was observed in non-heated oil and the oil heated for 5 hours but non-Newtonian motion was observed in the oil heated for more than 10 hours and at high shear stress. The fatty acid compositions were analyzed by gas liquid chromatography and all the components of fatty acids were reduced in amounts with extention of heating time. The acid value, peroxide value and density were increased but iodine value were decreased with extension of heating time.