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991.
Interference of GSM mobile phones with communication between Cardiac Rhythm Management devices and programmers: A combined in vivo and in vitro study 下载免费PDF全文
992.
Isolation of New Delhi metallo‐β‐lactamase 1‐producing Vibrio cholerae non‐O1, non‐O139 strain carrying ctxA,st and hly genes in southern Vietnam 下载免费PDF全文
Tai The Diep Nhi Thi Ngoc Nguyen Thi Ngoc Cat Nguyen Huy Khac An Truong Quang Nguyen Vu Hoang Nguyen Thuong Van Nguyen Thu Ngoc Anh Nguyen Hidemasa Izumiya Makoto Ohnishi Tetsu Yamashiro Lan Thi Phuong Nguyen 《Microbiology and immunology》2015,59(5):262-267
Vibrio cholerae non‐O1, non‐O139 (VC_NAG) organisms are universally present in the aquatic environment and regarded as non‐pathogenic bacteria. However, considering that they do occasionally induce gastroenteritis, a study of their virulence and antibiotic resistance genes is important. The presence of enteropathogenic genes, including ctxA, VC_NAG‐specific heat‐stable toxin gene (st), hemolysin (hly), and zona occludens toxin (zot) was determined by PCR in 100 VC_NAG strains isolated in southern Vietnam in 2010–2013 from 94 environmental and six human origins. These 100 VC_NAG strains were also tested phenotypically and genotypically for the presence of the New Delhi metallo‐β‐lactamase (NDM‐1). Of the 100 VC_NAG strains tested, six were positive for ctxA; five from the environment and one of human origin. The st gene was detected in 17 isolates, 15 and two of which were of environmental and human origins, respectively. Gene hly was detected in 19 VC_NAG strains examined, two of which were isolated from humans and 17 from environments. The zot gene was not detected in any of the strains tested. Three VC_NAG strains of environmental origin were confirmed to produce NDM‐1 and the blaNDM‐1 gene was detected in those strains by PCR. Of note, one of the three NDM‐1‐producing VC_NAG strains was confirmed to carry ctxA, st and hly genes concurrently. This is the first report of isolation of NDM‐1‐producing VC_NAG strains in Vietnam. 相似文献
993.
Juvenile hormone III (JH III) plays primary roles in regulation of metamorphosis, reproduction and diapause in Leptinotarsa decemlineata, a notorious defoliator of potato. The neurosecretory cell-borne substance(s) negatively affects the final two steps in JH biosynthesis, catalyzed respectively by an epoxidase CYP15A1 and a juvenile hormone acid methyltransferase (JHAMT). In a few insect species other than L. decemlineata, the inhibitory substance is allatostatin (AS) neuropeptide. In this study, two putative AS genes encoding LdAS-C and LdAS-B precursors were cloned. Both LdAS-C and LdAS-B were expressed in the egg, larvae, pupae and adults, and highly expressed in the brain and the gut. Dietary introduction of double-stranded RNAs (dsRNAs) targeting LdAS-C and LdAS-B successfully knocked down respective target genes. Ingestion during 3 and 6 consecutive days of dsLdAS-C significantly increased the LdJHAMT mRNA levels by 3.8 and 9.9 fold respectively. In contrast, ingestion of dsLdAS-B only slightly increased the LdJHAMT expression level by 1.1 and 1.7 fold. Moreover, after one, two and three days' ingestion of dsLdAS-C, the relative JH levels in the hemolymph of treated larvae were 2.5, 4.2 and 1.9 fold higher than those in control beetles. Furthermore, ingestion of dsLdAS-C and dsLdAS-B significantly affected larval growth and delayed larval development. Thus, we provide a line of experimental evidence in L. decemlineata to support the concept that AS-C acts as an allatostatin and inhibit JH biosynthesis. 相似文献
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Yuping Zhang Deyu Hu Xingang Meng Qingcai Shi Pei Li Linhong Jin Kankan Zhang Baoan Song 《Chirality》2015,27(3):262-267
The stereoselective degradation of indoxacarb enriched with (+)‐S‐indoxacarb (S/R:70/30) was investigated in three typical green teas. A convenient and precise chiral method was developed and validated for measuring indoxacarb enantiomers in green tea. The developed method was based on high‐performance liquid chromatography coupled with tandem mass spectrometry using a Chiralpak IC column. The stereoselective degradation of indoxacarb enantiomers showed that the (+)‐S‐enantiomer dissipated faster than the (?)‐R‐enantiomer in all three typical tea farms. However, no enantiomerization was observed after applying pure (+)‐S‐indoxacarb. Residues on tea plant of the active ingredient (+)‐S‐indoxacarb from suspension concentrate (SC) was more persistent than that from emulsifiable concentrate (EC). Chirality 27:262–267, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
998.
Catalytic activities of neutral and charged palladium (Pd) nanoparticles are compared for hydrogen reduction half-reaction. In this work the sequential H2 dissociation from the surface of a Pd13H24 cluster is systematically studied by ab initio molecular dynamics (AIMD) at the density functional theory level. AIMD simulation is launched by preparing initial values of momenta of all nuclei in the model corresponding to a temperature range of 0–1700 K. AIMD simulation provides the trajectories of all the atoms in the cluster. A sequential H2 desorption up to seven molecules is observed from the cluster surface due to thermal motion of nuclei. Modifications of total charge on the neutral Pd13H24 cluster model are found to affect surface H2 desorption behaviour. A desorption rate of H2 molecule on both neutral and charged Pd13H24 clusters is compared to the data of Pt13H24 cluster reported previously. The H2 desorption energy on all the investigated clusters is also determined. The results reveal that Pd13 cluster presents a higher catalytic activity than Pt13 cluster. 相似文献
999.
Biochar amendment to soils impairs developmental and reproductive performances of a major rice pest Nilaparvata lugens (Homopera: Delphacidae) 总被引:1,自引:0,他引:1 下载免费PDF全文
Biochar amendments to soils had aroused much interest for having potential for greenhouse gas mitigation, soil improvement and increased crop productivity. However, little attention had been focused on the influence of biochar amendments on herbivorous insect pests. This study investigated whether a biochar amendment affected developmental and reproductive performances of the rice brown planthopper (Nilaparvata lugens) feeding on rice plants. The biochar from the pyrolysis of wheat straw was used for treatments of soils (from a fallow rice field), and the treated soils were applied to grow rice seedlings in small vials, in which N. lugens life history was observed. The nymphal development time was delayed and nymph‐to‐adult survival decreased with a high level of 200 g/kg biochar application. Herbivore lifetime fecundity decreased with increasing amounts of biochar, from 256 eggs under the control down to 69 eggs under the high level (200 g/kg) of biochar application. Egg‐hatching rate significantly decreased at the highest biochar level (200 g/kg), compared to the other lower biochar levels. Our results suggest that biochar amendment to rice fields may have negative impacts on the rice brown planthoppers when applied at level of 200 g/kg of soil. 相似文献
1000.
Longyan Yang Junfang Zheng Ying Xiong Ran Meng Qian Ma Hua Liu Hui Shen Shuai Zheng Songlin Wang Junqi He 《Amino acids》2015,47(7):1455-1464