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251.
Electrospun web may possibly be widely applied to protective garments or specialty textiles due to its high level of protection
as well as comfort. Of particular interest in this study is to develop waterproof-breathable fabric by applying electrospun
web of polyurethane directly onto the substrate fabric. The optimal electrospinning condition was examined with regards to
the concentration, applied voltage and tip-to-collector distance. Solvent-electospinning of polyurethane was performed at
the optimum condition, using N,N-dimethylacetamide as solvent. The thickness of 0.02 mm of electrospun web was applied onto
the polyester/nylon blended fabric. For comparison, the polyester/nylon fabrics were coated with 0.02 mm thickness of polyurethane
resin membranes adopting four different conditions. The electrospun PU web/fabric was compared to resin coated fabrics in
terms of water-proof and breathable properties. The electrospun web applied fabric showed higher air permeability, vapor transmission,
and thermal insulation properties than resin coated fabrics, which can be translated as greater comfort sensation of electrospun
applied fabrics. However, water resistance value of electrospun web applied fabric did not reach that of resin coated fabrics. 相似文献
252.
Young Min Im Tae Hwan Oh Jin Wook Cha Young Ho Seo Jun Sung Hwang Joseph A. Nathanael Sung Soo Han Soon Ho Jang 《Fibers and Polymers》2014,15(10):2066-2071
Poly(vinyl alcohol) (PVA)/zirconium oxide (ZrO2) composite nanofibers with a skin-core structure were prepared and the effect of ZrO2 particle content on uniform web formation was investigated. The optimized polymer concentration, tip to collector distance, and applied voltage for electrospinning were 11 wt%, 12 cm, and 20 kV, respectively. Skin-core PVA/ZrO2 composite nanofibers containing up to 12 wt% ZrO2 were successfully prepared, but it was difficult to obtain PVA/ZrO2 composite nanofiber webs via conventional electrospinning. Increasing the amount of ZrO2 caused the morphology of the PVA/ZrO2 composite nanofibers to become a non-uniform nanoweb with irregular nanofiber diameters. While it was difficult to obtain a uniform nanofiber web containing a content of ZrO2 over 6 wt% for conventional electrospinning, a more uniform nanofiber web could be obtained at up to 9 wt% ZrO2 using a skin-core dual nozzle. More uniform webs could also be obtained when ZrO2 was in the skin rather than the core. 相似文献
253.
In this study, we elucidated the inhibitory effect of fucoidan from marine brown algae on the lipid accumulation in differentiated 3T3-L1 adipocytes and its mechanism. The treatment of fucoidan in a dose-dependent manner was examined on lipid inhibition in 3T3-L1 cells by using Oil Red O staining. Fucoidan showed high lipid inhibition activity at 200 μg/mL concentration (P < 0.001). Lipolytic activity in adipocytes is highly dependent on hormone sensitive lipase (HSL), which is one of the most important targets of lipolytic regulation. Here, we examined the biological response of fucoidan on the protein level of lipolysis pathway. The expressed protein levels of total hormone sensitive lipase (HSL) and its activated form, phosphorylated-HSL were significantly increased at concentration of 200 μg/mL fucoidan. Furthermore, insulin-induced 2-deoxy-D-[3H] glucose uptake was decreased up to 51% in fucoidan-treated cells as compared to control. Since increase of HSL and p-HSL expression and decrease of glucose uptake into adipocytes are known to lead to stimulation of lipolysis, our results suggest that fucoidan reduces lipid accumulation by stimulating lipolysis. Therefore, these results suggest that fucoidan can be useful for the prevention or treatment of obesity due to its stimulatory lipolysis. 相似文献
254.
Sung Ok Sohn So Min Lee Yun Mi Kim Jeong Hyun Yeum Jin Hyun Choi Han Do Ghim 《Fibers and Polymers》2007,8(2):163-167
A durable aroma finishing for PET fabric was carried out by adopting poly(vinyl acetate) (PVAc) nanoparticles containing lavender
oil (LO) in core. Relatively small size of PVAc nanoparticles (ca. 244 nm of mean particle diameter) was expected to resist
the frictional destruction of the particles, which is frequently observed in cases of microcapsules. PVAc nanoparticles containing
LO in core were prepared by emulsification-diffusion method and their application as an aroma releasing agent for PET fabrics
was assessed through the observation of releasing profiles of LO in ethanol for experimental acceleration. Melamine-formaldehyde
(MF) microcapsules containing LO were also prepared and treated on fabrics for comparison. PVAc nanoparticles treated on PET
fabric showed higher initial releasing amount, which was ascribed to the enhanced surface area. After 2 days of releasing,
PET fabric treated with PVAc nanoparticles showed slower and more stable releasing profile and reached about 12 ppm of cumulative
release after 16 days, which was under two thirds of that with MF microcapsules. PVAc nanoparticles can be used as an agent
for durable aroma finishing of PET fabrics. 相似文献
255.
Five new nardosinane-type sesquiterpenoids, paralemnolins Q-U (1-5), along with three known compounds (6-8), were isolated from the Formosan soft coral Paralemnalia thyrsoides. The structures of new metabolites were elucidated on the basis of extensive spectroscopic methods, and the absolute configuration of 1 was determined by the application of Mosher's method on 1. Among these metabolites, 1 and 3 are rarely found nardosinane-type sesquiterpenoids, possessing novel polycyclic structures. Compounds 1, 3, 6 and 7 were found to possess neuroprotective activity. 相似文献
256.
Jae?Whan?ChoEmail author Sun?Hwa?Lee Jung?Hyun?So Jae?Yun?Jaung Kee?Jong?Yoon 《Fibers and Polymers》2004,5(3):239-244
Solution-cast films of polymethylmethacrylate (PMMA) and polyurethane (PU) containing polymeric styryl dye up to 5% by weight
were prepared to investigate their acid-sensitivity and mechanical and thermal properties. Original red samples due to styryl
dye turned out yellow very rapidly as they were exposed to acid vapor of hydrochloric acid or p-toluenesulfonic acid. According
to UV/VIS spectroscopic measurements, characteristic peak intensities near 430 nm and 520 nm increased or decreased relatively
with exposed amounts of acid, respectively. Both PMMA and PU samples showed uniform color distribution due to a good miscibility
between polymer and dye which can be evidenced by measurements of glass transition temperature. No significant difference
in acid-sensitivity was found between PU and PMMA except relative absorbance. However, dependence of their mechanical properties
on dye content was somewhat different with PU or PMMA. In case of PMMA, modulus and breaking stress increased up to about
50% with increasing dye content, whereas those of PU samples showed only slight increase. It was ascribed to whether the matrix
polymer was in the glassy or rubbery state. 相似文献
257.
Youn?Hee?Jeon Won?Young?Jeong Jung?Woo?Park Seung?Kook?AnEmail author 《Fibers and Polymers》2003,4(4):151-155
The abrasion behavior of three kinds of warp knitted fabrics, which are normally used for upper sole of footwear, was evaluated.
We measured the changes of mechanical and structural properties of each sample as abrasion cycle increased. Each sample showed
similar trends in compression and surface properties but there were significant differences in abrasion rate among the samples.
The mechanical properties showed remarkable differences with directions. The frictional coefficient (MIU) of fabric surface
increased at the beginning of abrasion and decreased as abrasion cycles increased. The weight and thickness of the fabric
linearly decreased with abrasion cycles. The surface roughness (SMD) and the compressional resilience (RC) decreased as abrasion
cycles increased while compressional energy (WC) increased. 相似文献
258.
Nam SM Hwang IK Yi SS Yoo KY Park OK Yan B Song W Won MH Yoon YS Seong JK 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(8):1037-1042
In this study, we investigated the effects of treadmill exercise on calretinin (CR), a marker of early postmitotic neurons, immunoreactivity in the dentate gyrus (DG) of Zucker diabetic fatty (ZDF) rats, before or after diabetes onset, and Zucker lean control (ZLC) rats. For this study, 6-week-old ZLC and prediabetic ZDF rats, and 22-week-old ZLC and ZDF rats were exercised on the treadmill. Sedentary ZLC and ZDF rats of the same age were used as exercise experiment controls. The exercised prediabetic ZDF rats did not show diabetes onset, while the sedentary prediabetic ZDF rats showed significantly increased blood glucose levels. The exercised diabetic ZDF rats exhibited a decrease in their blood glucose levels compared to the sedentary diabetic ZDF rats, but the levels were still above 20 mmol/l. ZLC rats of both ages were in the normoglycemic range. CR immunoreactivity was detected throughout the DG, including the subgranular zone and the polymorphic layer. Diabetic rats exhibited a significant decrease in the number of CR-immunoreactive cells and fibers in the DG. Exercise in the prediabetic ZDF rats significantly increased the number of CR-immunoreactive cells and fibers in the subgranular zone of the DG. In the ZLC and ZDF rats of chronic diabetic phase, exercise increased CR-immunoreactive neurons in the hilar region. These results suggest that diabetes significantly reduces the number of postmitotic CR-immunoreactive neurons and the intensity of immunoreactivity and that exercise increases these CR-related parameters in a diabetic stage-dependent manner. 相似文献
259.
Truong LQ Kim JT Yoon BI Her M Jung SC Hahn TW 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(12):1597-1601
Brucella infections in wildlife originate either from contact with infected livestock or from a natural sustainable reservoir in wildlife populations. As South Korea has set a goal of brucellosis eradication by 2013, it is necessary to determine the prevalence of Brucella in wildlife and wild rodents. This information will play an important role in the control of brucellosis. Because of the absence of prominent clinical signs, direct and indirect laboratory tests are essential for diagnosing brucellosis. In this study, tissue and blood samples were taken from wild animals, abandoned dogs, a cat and wild rodents, and they were tested for Brucella or Brucella-specific antibodies by isolation, PCR and serology. Results showed that 18.6% (33/177) of blood samples were positive by PCR, and 5.7% (11/194) were positive by C-ELISA. However, none of these samples yielded culturable bacteria. Of the tissue samples, 9.7% (8/82) were positive by PCR. Brucella was isolated from only one tissue culture from a Chinese water deer carcass. This Brucella species was identified as Brucella abortus biovar 1 by biotyping, 16S rRNA PCR and the Bruce-ladder PCR assay. In this study, we reported the prevalence of Brucella in wildlife, dogs, a cat and rodents by using serological and molecular methods, and we report the first isolation of B. abortus in wild Chinese water deer in South Korea. 相似文献
260.