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951.
Biodegradation of 2,4-Dichlorophenol through a Distal meta-Fission Pathway 总被引:4,自引:0,他引:4 下载免费PDF全文
Alcaligenes eutrophus JMP222, a derivative of A. eutrophus JMP134 which has lost plasmid pJP4 (encoding the tfd genes for the ortho fission pathway), was induced for the meta fission pathway when grown on o-cresol. Resting cell suspensions, grown on o-cresol, oxidized 2,4-dichlorophenol (2,4-DCP), a degradation product of 2,4-dichlorophenoxyacetic acid, to 3,5-dichlorocatechol. Further degradation of 3,5-dichlorocatechol was observed by the production of a yellow ring fission product with liberation of chloride. Oxidation of 2,4-DCP (305 (mu)M) in 47 hs resulted in 69% dehalogenation through this pathway. The ring fission product was characterized as 2-hydroxy-3,5-dichloro-6-oxo-hexa-2,4-dienoic acid by gas chromatography-mass spectrometry and gas chromatography-Fourier transform infrared spectroscopy. These data indicate that 2,4-DCP is degraded through a distal meta ring fission pathway, in contrast to either a suicidal proximal fission or the standard ortho fission pathway. 相似文献
952.
Anti-stress and anti-fatigue effects of fermented rice bran. 总被引:2,自引:0,他引:2
K M Kim K W Yu D H Kang J H Koh B S Hong H J Suh 《Bioscience, biotechnology, and biochemistry》2001,65(10):2294-2296
The anti-stress and anti-fatigue effects on rats and mice of a hot water extract of rice bran fermented with Saccharomyces cerevisae IFO 2346 were investigated. Oral administration (1 g/kg/day) of the hot water extract of fermented rice bran (FRB) inhibited major changes in the weight of the adrenal, thymus, spleen and thyroid, showing an anti-stress effect. The hot water extract of FRB also inhibited increases in the GPT and LDH activity, cholesterol and glucose in the serum. The administration (1 g/kg/day) for 2 weeks significantly prolonged the swimming time, resulting in an increase in the anti-fatigue effect. It is considered from these results that FRB had anti-stress and anti-fatigue effects. 相似文献
953.
Experiments detecting low gyromagnetic nuclei have recently been proposed to utilize the relatively slow relaxation properties
of these nuclei in comparison to 1H. Here we present a new type of 15N direct-detection experiment. Like the previously proposed CaN experiment (Takeuchi et al. in J Biomol NMR 47:271–282, 2010), the hCaN experiment described here sequentially connects amide 15N resonances, but utilizes the initial high polarization and the faster recovery of the 1H nucleus to shorten the recycling delay. This allows recording 2D 15N-detected NMR experiments on proteins within a few hours, while still obtaining superior resolution for 13C and 15N, establishing sequential assignments through prolines, and at conditions where amide protons exchange rapidly. The experiments
are demonstrated on various biomolecules, including the small globular protein GB1, the 22 kDa HEAT2 domain of eIF4G, and
an unstructured polypeptide fragment of NFAT1, which contains many SerPro sequence repeats. 相似文献
954.
955.
Seema Untawale Andrew O. Odegaard Woon-Puay Koh Ai Zhen Jin Jian-Min Yuan Kristin E. Anderson 《PloS one》2014,9(1)
Few studies have examined the association between body mass index (BMI: kg/m2) and pancreatic cancer risk in Asian populations. We examined this relationship in 51,251 Chinese men and women aged 45–74 who enrolled between 1993 and 1998 in the population based, prospective Singapore Chinese Health Study. Data were collected through in-person interviews. By December 31, 2011, 194 cohort participants had developed pancreatic cancer. A Cox proportional hazards model was used to estimate hazard ratios (HR) and their 95% confidence intervals (95% CI). We hypothesized the association between BMI and pancreatic cancer risk may vary by smoking status (ever v. never) and there was evidence for this as the interaction between BMI and smoking status was significant (p = 0.018). Among ever smokers, being classified as underweight (BMI <18.5 kg/m2), was associated with a significantly elevated risk of pancreatic cancer relative to smokers with a BMI of 21.5–24.4 kg/m2 (HR = 1.99, 95% CI = 1.03–3.84). This association was strengthened after exclusion of the first three years of follow-up time. Among never smokers, there was no association between BMI and pancreatic cancer risk. However, after excluding pancreatic cancer cases and person-years in the first three years of follow-up, never smokers with a BMI ≥ 27.5 kg/m2 showed a suggestive increased risk of pancreatic cancer relative to never smokers with a BMI of 21.5–24.4 kg/m2 (HR = 1.75, 95% CI = 0.93–3.3). In conclusion, Singaporean Chinese who were underweight with a history of smoking had an increased risk of developing pancreatic cancer, whereas there was no significant association between BMI and pancreatic cancer in never smokers. 相似文献
956.
Hiroko Ogata-Kawata Masashi Izumiya Daisuke Kurioka Yoshitaka Honma Yasuhide Yamada Koh Furuta Toshiaki Gunji Hideki Ohta Hiroyuki Okamoto Hikaru Sonoda Masatoshi Watanabe Hitoshi Nakagama Jun Yokota Takashi Kohno Naoto Tsuchiya 《PloS one》2014,9(4)
Purpose
Exosomal microRNAs (miRNAs) have been attracting major interest as potential diagnostic biomarkers of cancer. The aim of this study was to characterize the miRNA profiles of serum exosomes and to identify those that are altered in colorectal cancer (CRC). To evaluate their use as diagnostic biomarkers, the relationship between specific exosomal miRNA levels and pathological changes of patients, including disease stage and tumor resection, was examined.Experimental Design
Microarray analyses of miRNAs in exosome-enriched fractions of serum samples from 88 primary CRC patients and 11 healthy controls were performed. The expression levels of miRNAs in the culture medium of five colon cancer cell lines were also compared with those in the culture medium of a normal colon-derived cell line. The expression profiles of miRNAs that were differentially expressed between CRC and control sample sets were verified using 29 paired samples from post-tumor resection patients. The sensitivities of selected miRNAs as biomarkers of CRC were evaluated and compared with those of known tumor markers (CA19-9 and CEA) using a receiver operating characteristic analysis. The expression levels of selected miRNAs were also validated by quantitative real-time RT-PCR analyses of an independent set of 13 CRC patients.Results
The serum exosomal levels of seven miRNAs (let-7a, miR-1229, miR-1246, miR-150, miR-21, miR-223, and miR-23a) were significantly higher in primary CRC patients, even those with early stage disease, than in healthy controls, and were significantly down-regulated after surgical resection of tumors. These miRNAs were also secreted at significantly higher levels by colon cancer cell lines than by a normal colon-derived cell line. The high sensitivities of the seven selected exosomal miRNAs were confirmed by a receiver operating characteristic analysis.Conclusion
Exosomal miRNA signatures appear to mirror pathological changes of CRC patients and several miRNAs are promising biomarkers for non-invasive diagnosis of the disease. 相似文献957.
Feng Cao Chao Zhang Tat Thang Vo Doan Yao Li Daniyal Haider Sangi Jie Sheng Koh Ngoc Anh Huynh Mohamed Fareez Bin Aziz Hao Yu Choo Kazuo Ikeda Pieter Abbeel Michel M. Maharbiz Hirotaka Sato 《PloS one》2014,9(8)
In this study, a biological microactuator was demonstrated by closed-loop motion control of the front leg of an insect (Mecynorrhina torquata, beetle) via electrical stimulation of the leg muscles. The three antagonistic pairs of muscle groups in the front leg enabled the actuator to have three degrees of freedom: protraction/retraction, levation/depression, and extension/flexion. We observed that the threshold amplitude (voltage) required to elicit leg motions was approximately 1.0 V; thus, we fixed the stimulation amplitude at 1.5 V to ensure a muscle response. The leg motions were finely graded by alternation of the stimulation frequencies: higher stimulation frequencies elicited larger leg angular displacement. A closed-loop control system was then developed, where the stimulation frequency was the manipulated variable for leg-muscle stimulation (output from the final control element to the leg muscle) and the angular displacement of the leg motion was the system response. This closed-loop control system, with an optimized proportional gain and update time, regulated the leg to set at predetermined angular positions. The average electrical stimulation power consumption per muscle group was 148 µW. These findings related to and demonstrations of the leg motion control offer promise for the future development of a reliable, low-power, biological legged machine (i.e., an insect–machine hybrid legged robot). 相似文献
958.
Ya-Chen Lee Sheng-Shiung Chen Chia-Lin Koh I-Ping Hsueh Kai-Ping Yao Ching-Lin Hsieh 《PloS one》2014,9(10)
Background
The Barthel Index (BI) assesses actual performance of activities of daily living (ADL). However, comprehensive assessment of ADL functions should include two other constructs: self-perceived difficulty and ability.Objective
The aims of this study were to develop two BI-based Supplementary Scales (BI-SS), namely, the Self-perceived Difficulty Scale and the Ability Scale, and to examine the construct validity of the BI-SS in patients with stroke.Method
The BI-SS was first developed by consultation with experts and then tested on patients to confirm the clarity and feasibility of administration. A total of 306 participants participated in the construct validity study. Construct validity was investigated using Mokken scale analysis and analyzing associations between scales. The agreement between each pair of the scales’ scores was further examined.Results
The Self-perceived Difficulty Scale consisted of 10 items, and the Ability Scale included 8 items (excluding both bladder and bowel control items). Items in each individual scale were unidimensional (H≥0.5). The scores of the Self-perceived Difficulty and Ability Scales were highly correlated with those of the BI (rho = 0.78 and 0.90, respectively). The scores of the two BI-SS scales and BI were significantly different from each other (p<.001). These results indicate that both BI-SS scales assessed unique constructs.Conclusions
The BI-SS had overall good construct validity in patients with stroke. The BI-SS can be used as supplementary scales for the BI to comprehensively assess patients’ ADL functions in order to identify patients’ difficulties in performing ADL tasks, plan intervention strategies, and assess outcomes. 相似文献959.
Insertion of core CpG island element into human CMV promoter for enhancing recombinant protein expression stability in CHO cells 下载免费PDF全文
Mariati Jessna H. M. Yeo Esther Y. C. Koh Steven C. L. Ho Yuansheng Yang 《Biotechnology progress》2014,30(3):523-534
The human cytomegalovirus promoter (hCMV) is susceptible to gene silencing in CHO cells, most likely due to epigenetic events, such as DNA methylation and histone modifications. The core CpG island element (IE) from the hamster adenine phosphoribosyltransferase gene has been shown to prevent DNA methylation. A set of modified hCMV promoters was developed by inserting one or two copies of IE in either forward or reverse orientations either upstream of the hCMV enhancer, between the enhancer and core promoter (CP), or downstream of the CP. The modified hCMV with one copy of IE inserted between the enhancer and core promoter in reverse orientation (MR1) was most effective at enhancing expression stability without compromising expression level when compared with the wild‐type (WT) hCMV. A third of 18 EGFP expressing clones generated using MR1 retained 70% of their starting expression level after 8 weeks of culture in the absence of selection pressure, while none of 18 WT hCMV generated clones had expression above 50%. MR1 also improved antibody expression stability of methotrexate (MTX) amplified CHO cell lines. Stably transfected pools generated using MR1 maintained 62% of their original monoclonal antibody titer after 8 weeks of culture in the absence of MTX, compared to only 37% for WT hCMV pools. Low levels of CpG methylation within both WT hCMV and MR1 were observed in all the analyzed cell lines and the methylation levels did not correlate to the expression stability, suggesting IE enhances expression stability by other mechanisms other than preventing methylation. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:523–534, 2014 相似文献
960.
Sang-Ho Choi Sang-Bum Hong Hyo-Lim Hong Sung-Han Kim Jin Won Huh Heungsup Sung Sang-Oh Lee Mi-Na Kim Jin-Yong Jeong Chae-Man Lim Yang Soo Kim Jun Hee Woo Younsuck Koh 《PloS one》2014,9(5)