排序方式: 共有21条查询结果,搜索用时 15 毫秒
1.
Chan-Hee Park Tae-Hyung Kim Do-Hee Lee Leonard D. Tijing Mi-Hwa Yu Sang-Don Moon Cheol Sang Kim 《Metallurgical and Materials Transactions A》2012,43(9):3006-3010
We report here for the first time the use of magnetic polishing to improve the surface finish of titanium-nickel (TiNi) stents for better performance. We investigated the effects of polishing time and rotational speed on the average surface roughness, surface chemical contents, and push-out load of stents. The magnetically polished stents show a decrease of 2.3 to 17.9?pct in surface roughness and a lower push-out load for stent deployment from the catheter. 相似文献
2.
Seung-Hong Lee Jung-In Choi Soo-Jin Heo Mi-Hwa Park Pyo-Jam Park Byong-Tae Jeon Se-Kwon Kim Ji-Sook Han You-Jin Jeon 《Food science and biotechnology》2012,21(1):239-246
Pancreatic β cells are very sensitive to oxidative stress and this may play an important role in β cell death in diabetes.
The protective effect of diphlorethohydroxycarmalol (DPHC), one of phlorotannin polyphenol compound purified from pae (Ishige okamurae) against high glucoseinduced oxidative stress was investigated using RINm5F pancreatic β cells. High glucose (30 mM) treatment
induced RINm5F pancreatic β cells cell death, but DPHC, at concentration 10 or 50 μg/mL, significantly inhibited the high
glucose-induced glucotoxicity and apoptosis. Furthermore, treatment with DPHC dose-dependently decreased thiobarbituric acid
reactive substances (TBARS), intracellular reactive oxygen species (ROS) generation and nitric oxide level increased by high
glucose. In addition, DPHC treatment increased activities of antioxidant enzymes including catalase (CAT), superoxide dismutase
(SOD), and glutathione peroxidase (GSH-px) in high glucose pretreated RINm5F pancreatic β cells. DPHC treatment improved the
secretory responsiveness following stimulation with glucose. These findings indicate that DPHC might be used as potential
nutraceutical agent which will protect the glucotoxicity caused by hyperglycemia-induced oxidative stress associated with
diabetes. 相似文献
3.
Seung-Hong Lee Mi-Hwa Park Ji-Sook Han Yoonhwa Jeong Misook Kim You-Jin Jeon 《Food science and biotechnology》2012,21(4):1149-1155
This study was designed to investigate whether the brown alga gamtae (Ecklonia cava) may inhibit α-glucosidase and α-amylase activities, and alleviate postprandial hyperglycemia in streptozotocin-induced diabetic mice. For that purpose, we prepared an enzymatic hydrolysate from gamtae (EHG) by using the carbohydrase, Celluclast. EHG evidenced prominent inhibitory effect against α-glucosidase and α-amylase. The IC50 values of EHG against α-glucosidase and α-amylase were 0.62 and 0.59 mg/mL, respectively, which evidenced the higher activities than that of acarbose. EHG did not exert any cytotoxic effect in human umbilical vein endothelial cells (HUVECs) at various concentrations (from 0.25 to 2 mg/mL). The increase of postprandial blood glucose levels were significantly suppressed in the EHG administered group than those in the streptozotocin-induced diabetic or normal mice. Moreover, the area under curve (AUC) was significantly reduced via EHG administration (6,102 vs. 10,425 mg·min/dL) in the diabetic mice as well as it delays absorption of dietary carbohydrates. These result indicated that EHG might be a potent inhibitor for α-glucosidase and α-amylase. 相似文献
4.
In this study, biodegradable films were prepared by using corn starch, PVA, nano-sized poly(acrylamide-co-methyl methacrylate) (PAAm-co-MMA), nano-sized TiO2(P-25)/PAAm-co-MMA composite, and additives which are harmless to the human body, that is, glycerol (GL) and citric acid (CA). Nano-sized PAAm-co-MMA was synthesized by the method of emulsion polymerization. Also, nano-sized TiO2/PAAm-co-MMA composites were synthesized by wet milling for 48 h. The morphology and crystallinty of nano-sized PAAm-co-MMA and TiO2/PAAm-co-MMA composite was observed by the SEM and XRD. The physical properties such as tensile strength (TS), elongation at break (%E), degree of swelling (DS), and solubility (S) of biodegradable films were investigated. The photocatalytic degradability of starch/PVA/nano-sized TiO2/PAAm-co-MMA composite blended films was evaluated using methylene blue as photodegradation target. 相似文献
5.
Mi-Hwa Baek Won-Chae Jung Ji-Won Yoon Ji-Sook Hong Young-Seak Lee Jeong-Kwon Suh 《Journal of Industrial and Engineering Chemistry》2013,19(2):469-477
The influences of heat-treatment temperature and activation time on the properties of TiO2 supported on spherical activated carbon (TiO2/SAC) were investigated. Nano-sized TiO2 was dispersed on the spherical activated carbon with the size of 10–30 nm. Some anatase phase of TiO2 was transformed to rutile phase of TiO2 with an increase of heat-treatment temperature. All of the TiO2/SAC photocatalysts had microporous structure, with the mesopore volume increasing over an activation time of 6 h. The TiO2/SAC photocatalysts obtained at activation times of 6 h and 9 h were observed synergistic effects between adsorption and photocatalysis in the removal of humic acid. 相似文献
6.
Ae-Rim Kim Mi-Hwa Oh Kuk-Hwan Seol Gi-Won Shin Gyoo Yeol Jung Sangsuk Oh 《Food science and biotechnology》2010,19(6):1441-1447
Capillary electrophoresis-based single-strand conformation polymorphism (CE-SSCP) coupled with multiplex polymerase chain
reaction (PCR) method was used for the detection of 7 pathogens associated with foodborne illness, including Salmonella enterica, Clostridium perfringens, Bacillus cereus, Listeria monocytogenes, Yersinia enterocolitica, Vibrio parahaemolyticus, and Escherichia coli O157:H7. The method was applied to model food systems, both of culture medium and cooked rice. The detection limit of individual
microbes was in the range of 101–103 CFU/g, and that of the mixture of 7 microbes was 103 CFU/g in the cooked rice sample. This method allowed the detection and identification of all 7 food-borne pathogens within
5 hr without the requirement for enrichment steps. 相似文献
7.
Mi-Hwa Lim Hyun-Suk Kim Nan-Young Kim Ho-Gi Kim Il-Doo Kim Seung Eon Moon Min-Hwan Kwak Han-Cheol Ryu Su-Jae Lee 《Journal of Electroceramics》2004,13(1-3):239-243
Highly (100) preferred undoped and 1–5% Ni-doped Ba1–xSrxTiO3 (BST) thin films were deposited onto MgO (100) single crystal substrate at 750°C using pulsed laser deposition. BST thin film-based interdigital capacitors (IDC) were prepared by standard photolithography process. The microwave properties of BST films were measured at 10 GHz. Ni-doped BST films showed better dielectric properties by exhibiting improved dielectric Q while retaining an appropriate capacitance tuning compared to undoped BST films. 1% Ni-doped BST film showed the maximum figure of merit of 2896.1. It is suggested that 1 mol% Ni doped BST film is an effective candidate for high performance tunable device applications. 相似文献
8.
Chae MH Park HK Kwon KI Kim JW Hong SI Kim Y Kim BH Kim IH 《Journal of food science》2011,76(4):C555-C559
Lipase-catalyzed interesterification of high oleic sunflower oil and fully hydrogenated soybean oil (70 : 30, wt/ wt) was carried out in a packed bed reactor using an immobilized lipase from Thermomyces lanuginosus (Lipozyme TL IM) and the effect of a stepwise temperature protocol involving the 2 different temperatures, 60 and 70 °C, was investigated. The melting point of a fat that was incubated at 70 °C for 9 min was 57 °C, which suggested that it should be to employ a lower reaction temperature of 60 °C, after the first 9 min of the reaction. There were no significant differences (P < 0.05) in the conversion degree, triacylglycerol profile, and solid fat content between a constant temperature protocol (70 °C) and a stepwise temperature protocol (a combination of 70 and 60 °C). After 50 cycles, the overall residual activities of enzymes employed in stepwise temperature protocol were significantly (P < 0.05) higher than those of enzymes employed in constant temperature protocol. 相似文献
9.
Suae Kim Mi-Hwa Lee Eun-Sook Lee Young-Do Nam Dong-Ho Seo 《Food science and biotechnology》2018,27(1):115-122
Seaweeds are considered as a health food partly due to the polysaccharide composition of the cell wall. Because conventional extraction methods have low yields and lead to environmental pollution, enzymatic methods have been proposed. In this study, a new strain of Bacillus sp. was isolated from cattle feces that produced a mannanase, a polysaccharide-degrading enzyme active against the green seaweed Codium fragile. The purified 39-kDa mannanase exhibited maximum activity at 55 °C and pH 6.0, and maintained its catalytic activity stably at temperatures up to 60 °C and at a broad pH range (5.0–11.0). Enzymatic activity was slightly enhanced by Cu2+ and Na+ but strongly inhibited by Fe2+, Ag+, and EDTA. The mannanase showed the highest specificity to the inexpensive substrates such as konjac powder and locust bean gum, and efficiently released various manno-oligosaccharides. This novel mannanase can thus be applicable in the food, feed, and pulp industries. 相似文献
10.
Montmorillonite surface properties and sorption characteristics for heavy metal removal from aqueous solutions 总被引:2,自引:0,他引:2
Surface properties of montmorillonite (MMT) and its adsorption characteristics for heavy metals have been investigated with nickel and copper as sorbate from aqueous solutions. Employing the potentiometric and mass titration techniques in batch experimental methods, the point of zero charge (PZC) and point of zero net proton charge (PZNPC) of MMT edges at different ionic strengths present pHPZC and pHPZNPC to be 3.4 ± 0.2. A crossing point was observed for the proton adsorption vs. pH curves at different ionic strengths of KCl electrolyte and in investigating MMT remediation potentialities as sorbent for heavy metals polluted waters, the effects of heavy metal concentration, pH, MMT dosage, reaction time and temperature for Cu2+ and Ni2+ uptake were studied. The sorption of metal ions by MMT was pH dependent and the adsorption kinetics revealed sorption rate could be well fitted by the pseudo-second-order rate model. The data according to mass transfer and intraparticle diffusion models confirmed diffusion of solutes inside the clay particles as the rate-controlling step and more important for the adsorption rate than the external mass transfer. Adsorption isotherms showed that the uptake of Cu2+ and Ni2+ could be described by the Langmuir model and from calculations on thermodynamic parameters, the positive ΔG° values at different temperatures suggest that the sorption of both metal ions were non-spontaneous. Change in enthalpy (ΔH°) for Ni2+ and Cu2+ were 28.9 and 13.27 kJ/mol K respectively, hence an endothermic diffusion process, as ion uptake increased with increase in temperature. Values of ΔS° indicate low randomness at the solid/solution interface during the uptake of both Cu2+ and Ni2+ by MMT. Montmorillonite has a considerable potential for the removal of heavy metal cationic species from aqueous solution and wastewater. 相似文献