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排序方式: 共有359条查询结果,搜索用时 15 毫秒
31.
Gin-Nae Ahn Kil-Nam Kim Seon-Heui Cha Choon-Bok Song Jehee Lee Moon-Soo Heo In-Kyu Yeo Nam-Ho Lee Young-Heun Jee Jin-Soo Kim Min-Soo Heu You-Jin Jeon 《European Food Research and Technology》2007,226(1-2):71-79
The potential antioxidant activities of three phlorotannins (phloroglucinol, eckol and dieckol) purified from Ecklonia cava collected in Jeju Island were investigated to evaluate their potential value as the natural products for foods or cosmetic
application. In this study, antioxidant activities were measured by electron spin resonance spectrometry (ESR) technique for
scavenging effects of free radicals such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), alkyl, hydroxyl (HO•) and superoxide anion radical (O2
•−) and by comet assay for protecting effects against H2O2-mediated DNA damage. The results show that all the phlorotannins have the potential DPPH, alkyl, hydroxyl and superoxide
radical scavenging activities. Especially, eckol samples scavenged around 93% of DPPH at 0.25, 0.5, 1 mg/mL of concentrations
and were higher than the other phlorotannins, such as phloroglucinol and dieckol samples. Also, protecting effects of the
phlorotannins against H2O2-mediated DNA damage increased with increased concentrations of the samples in the L5178 mouse T-cell lymphoma cell lines
(L5178Y-R). In conclusion, these results suggest that the three phlorotannins purified from E. cava have the potential inhibitory effect on H2O2-mediated DNA damage and harmful free radicals and can be used as antioxidants in cosmetic, foods and drug industry. 相似文献
32.
Jee Weng Tan Kwai Lin Thong Nirmala Devi Arumugam Wai Lian Cheah Yih Wei Lai Kek Heng Chua Raha Abdul Rahim Sabaratnam Vikineswary 《International Journal of Hydrogen Energy》2009,34(17):7538-7541
Molybdenum (Mo) nitrogenases consist of two components: dinitrogenase reductase (encoded by nifH) and the dinitrogenase or MoFe protein (encoded by nifDK). Nitrogenase enzyme of photosynthetic bacteria is responsible for hydrogen production. Therefore, primers were designed for the nitrogenase gene only. In this study, two primers (ND and NH) were designed after comparative genomic analysis of nifH and nifD gene sequences from public databases. The designed primers were used for the amplification of nifH and nifD genes to detect nitrogenase genes in photosynthetic bacteria. Initial detection was done using a monoplex Polymerase Chain Reactions (PCRs) followed by optimization of the PCR protocols. Subsequently, a duplex PCR was designed for amplification and detection of nifH and nifD genes in indigenous photosynthetic bacteria. Evaluation of the duplex PCR on six samples isolated from Palm Oil Mill Effluent (POME) showed that only four isolates contained both the nifH and nifD genes, indicating that these isolates were potential hydrogen-producing bacteria. PCR detection provides a rapid and efficient pre-identification of potential photosynthetic bacterial hydrogen producers. 相似文献
33.
Ah-Young Jee 《Carbon》2009,47(10):2546-31
Graphene-like carbon sheets were synthesized from adamantane in the solution phase at ambient temperature. Adamantane, C10H16, has a tetracyclic ring structure with four cyclohexanes in chair conformation. The two dimensional carbon structures were obtained by introducing ferrocene as the catalyst precursor and adamantane as the carbon source under sonication, proving that cyclohexane structures in adamantane can serve as a building block for graphene formation. The synthesized carbon sheets were characterized and confirmed by X-ray diffraction, high-resolution electron microscopy and atomic force microscopy. 相似文献
34.
Gwangbeom Heo Yuju Kim Eun-La Kim Soyeong Park Sang Hoon Rhee Jee H. Jung Eunok Im 《International journal of molecular sciences》2023,24(1)
Atractylodin is a major compound in the rhizome of Atractylodes lancea, an oriental herbal medicine used for the treatment of gastrointestinal diseases, including dyspepsia, nausea, and diarrhea. Recent studies have shown that atractylodin exerts anti-inflammatory effects in various inflammatory diseases. Herein, we investigated the anti-colitis effects of atractylodin and its molecular targets. We determined the non-cytotoxic concentration of atractylodin (50 μM) using a cell proliferation assay in colonic epithelial cells. We found that pretreatment with atractylodin significantly inhibits tumor necrosis factor-α-induced phosphorylation of nuclear factor-κ-light-chain-enhancer of activated B in HCT116 cells. Through docking simulation analysis, luciferase assays, and in vitro binding assays, we found that atractylodin has an affinity for peroxisome proliferator-activated receptor alpha (PPARα). Daily administration of atractylodin (40 mg/kg) increased the survival rate of mice in a dextran sodium sulfate-induced colitis mouse model. Thus, atractylodin can be a good strategy for colitis therapy through inducing PPARα-dependent pathways. 相似文献
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36.
Don Woong Choi Jee Yeun Kim Seon Hee Choi Hee Su Jung Hyo Joo Kim So Yean Cho Chan Soon Kang Seung Yeup Chang 《Food chemistry》2006
Although it has been known that pomegranate (Punica granatum L.) contains several steroid hormones, concrete experimental proofs about that have not been published until now. In order to identify and evaluate the contents of steroid hormones including estrone in pomegranate, we analyzed pomegranate seed, fruit juice and commercial preparations. We developed a reproducible and sensitive method for separation and identification of steroid hormones in pomegranate samples using both high performance liquid chromatography (HPLC)–PDA and gas chromatography (GC)–MS. In case of HPLC, an isocratic elution method using 35% aqueous acetonitrile solution at 1.0 ml/min with photodiode-array (PDA) detection at 225 nm and 254 nm was found to optimally separate and identify the steroid hormones from the pomegranate samples with a run time of less than 30 min. The pomegranate samples were comparatively analyzed to the HPLC results by GC/FID or GC/MS detection on a HP-1 (30 m length, 0.32 mm I.D.) with helium as carrier gas under the oven temperature control as follows: start 220 °C for 5 min, raising 5 °C per min, final 280 °C for 10 min. The HPLC and GC methods were successfully applied to the identification of steroid hormones in pomegranate samples. Our results suggested that there were no steroid estrogens including estrone, estradiol and testosterone in pomegranate seed, fruit juice and preparations. Consequently, we assumed that the previously reported analysts of pomegranate were misunderstood their analytical results according to either the estrogen-like effects or similarity of peak retention time and Rf values in experiments. 相似文献
37.
Tack-Jin Kim In-Kyu Choi Kyuseok Song Kwang-Yong Jee 《Journal of Nuclear Materials》2008,375(2):275-279
Both a potentiometric and a chronoamperometric electrochemical technique have been applied in an attempt to develop an efficient method for an on-line monitoring of a lithium metal reduction process of uranium oxides at a high-temperature in a molten salt medium. As a result of this study, it was concluded that the chronoamperometric method provided a simple and effective way for a direct on-line monitoring measurement of a lithium metal reduction process of uranium oxides at 650 °C by the measuring electrical currents dependency on a variation of the reduction time for the reaction. A potentiometric method, by adopting a homemade oxide ion selective electrode made of ZrO2 stabilized by a Y2O3 doping, however, was found to be inappropriate for an on-line monitoring of the reduction reaction of uranium oxide in the presence of lithium metal due to an abnormal behavior of the adopted electrodes. The observed experimental results were discussed in detail by comparing them with previously published experimental data. 相似文献
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40.
Inactivation of Bacillus cereus Spores on Red Chili Peppers Using a Combined Treatment of Aqueous Chlorine Dioxide and Hot‐Air Drying 下载免费PDF全文
The effect of a combined treatment using aqueous chlorine dioxide (ClO2) and hot‐air drying to inactivate Bacillus cereus spores on red chili peppers was evaluated. Ten washed and dried pepper samples, each comprising half of a single pepper (Capsicum annuum L.), were inoculated with B. cereus spore suspension. The inoculated samples were washed with sodium hypochlorite (NaOCl; 50, 100, or 200 μg/mL) or ClO2 (50, 100, or 200 μg/mL) solution for 1 min and then air‐dried (25 ± 1 °C, 47 ± 1% relative humidity), which was followed by drying with hot air at 55 °C for up to 48 h. The spore populations on the samples were enumerated and their aw and chromaticity values were measured. The spore numbers immediately after treatment with NaOCl and ClO2 were not significantly different. A more rapid reduction in spore numbers was observed in the samples treated with ClO2 than those treated with NaOCl during drying. A combined treatment of ClO2 and hot‐air drying significantly reduced the spore populations to below the detection limit (1.7 log CFU/sample). B. cereus spores on chili peppers were successfully inactivated by washing with ClO2 solution followed by hot‐air drying whereas the pepper color was maintained. 相似文献