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1.
Raves are all-night dance parties attended by large numbers of youth, sometimes in excess of 20,000. The rave scene, which is international in scope, is distinguished by clandestine venues, hypnotic electronic music and the liberal use of drugs such as ecstasy (3,4-methylenedioxymethamphetamine), GHB (gamma-hydroxybutyrate) and ketamine. Several rave-related deaths in Canada in 1999 alerted health authorities, parents and police to the health risks of rave attendance. Family physicians, emergency physicians and pediatricians should have some understanding of raves, the drugs and the health risks so they can effectively counsel and treat patients. The rave culture in Canada and the drugs commonly used at raves are reviewed, and strategies and initiatives for harm reduction are discussed. 相似文献
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The complete sequence of recombinant human interleukin-2 expressed in Escherichia coli has been confirmed by thermospray liquid chromatography-mass spectrometry (TS-LC-MS) of a tryptic digest derived from 100 micrograms (7 nmol) of reduced carboxymethylated interleukin-2. The preparation was shown by this method to contain predominantly unprocessed N-terminal initiator Met, with some authentic N-terminal Ala; the rest of the protein was as predicted from the DNA sequence, though some deamidated material was noted. TS-LC-MS proved to be a rapid and efficient method for surveying the protein tryptic peptide products allowing all the data to be collected in one chromatographic run; all tryptic fragments were identified by their molecular ions including those for the larger peptides (Mr 1500-3500) which, due to the presence of doubly and triply charged molecular ions, were brought within the mass range of the instrument (1800 Da). It is proposed that TS-LC-MS is a good general method for analyzing recombinant protein digests with respect to sequence confirmation, processing, and post-translational modification, and since each chromatographic peak is identified allows for subsequent monitoring of the protein by LC using uv detection. The method suffers from the disadvantages that all the sample is consumed during the experiment and that no fragment (sequence) ions are generally observed. 相似文献
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D. A. Peterson D. C. Peterson S. L. Archer E. K. Weir 《Redox report : communications in free radical research》2013,18(4):263-265
SummaryPolyunsaturated fatty acids (PUFAs) have been shown to modulate the activity of ionic channels by an unknown mechanism. Some channels are activated (i.e. certain delayed-rectifier, potassium channels) and others are inhibited (i.e. certain calcium, sodium and other potassium channels). We have previously demonstrated that PUFAs can act as electron carriers. It is known that ionic channels can be redox modulated. The ability of fatty acids to serve as electron shuttling agents is proportional to their unsaturation. These PUFAs cause reduction of disulfides through a superoxide radical-independent mechanism, probably related to enhanced electron delocalization. The present study shows that there is a strong correlation between the ability of a PUFA to transfer an electron to a disulfide and its reported ability to modulate ionic channels. This suggests that electron transfer could be the mechanism of PUFAs action on particular ionic channels. 相似文献
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Temporal Patterns of Reported Single-Vehicle Car and Truck Accidents in Texas, U.S.A. During 1980-1983 总被引:1,自引:0,他引:1
Peter H. Langlois Michael H. Smolensky Bartholomew P. Hsi Francis W. Weir 《Chronobiology international》1985,2(2):131-140
Reported single car and truck accidents due specifically to driver 'fatigue' for the 4-year span of 1980-1983 were analyzed for 24-hr, 7-d and 1-yr patterns. Three types of data were examined: (1) accidents in rural Texas, (2) accidents only in San Antonio, the fourth largest city in Texas and (3) accident ratio (number of accidents per time interval divided by traffic volume for the interval) in this city.
A statistically significant seasonal variation of relatively low amplitude with peaks in May and July was detected only for accidents in rural areas. High-amplitude periodicities of 7 d were evident in all the data sets, with a peak on the weekend. A very prominent 24-hr pattern was detected as well, with the acrophase determined by single cosinor around 0300. A slight secondary peak in accidents, around 1500, was evident in the data from the rural areas. This secondary peak represented a 12-hr rhythm in addition to the 24-hr. Overall, features of the temporal patterns in accidents over 24 hr and over the year in urban and rural areas differed only slightly. Accident ratios yielded results similar to accident frequencies. However, with regard to the rural data, the shape of the 24-hr temporal pattern varied with driver age; older drivers exhibited a flatter curve with a more pronounced afternoon rather than early morning (around 0300) peak. 相似文献
A statistically significant seasonal variation of relatively low amplitude with peaks in May and July was detected only for accidents in rural areas. High-amplitude periodicities of 7 d were evident in all the data sets, with a peak on the weekend. A very prominent 24-hr pattern was detected as well, with the acrophase determined by single cosinor around 0300. A slight secondary peak in accidents, around 1500, was evident in the data from the rural areas. This secondary peak represented a 12-hr rhythm in addition to the 24-hr. Overall, features of the temporal patterns in accidents over 24 hr and over the year in urban and rural areas differed only slightly. Accident ratios yielded results similar to accident frequencies. However, with regard to the rural data, the shape of the 24-hr temporal pattern varied with driver age; older drivers exhibited a flatter curve with a more pronounced afternoon rather than early morning (around 0300) peak. 相似文献
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D. R. Marshall B. S. Weir 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1985,69(5-6):463-474
Summary A general model for the evolution of pathogen populations on mixtures or multilines is developed. This model is used to extend previous analyses of the effects of the widespread cultivation of multilines on the evolution of virulence in obligate parasites to mixtures of lines carrying different numbers of resistance genes. It is concluded that the composition of an equilibrium pathogen population growing on a multiline may vary within wide limits and the prinicipal determinant of its composition is the number of components in the multiline and the resistance genes they carry. Other factors of importance are (i) the relative contribution made by each host class (with different numbers of resistance genes) to the pathogen spore pool each generation; (ii) the levels of stabilizing selection against unnecessary virulence genes; and (iii) the way in which unnecessary genes for virulence combine to reduce pathogen fitness. Conditions for the fixation of avirulent biotypes in the pathogen population and the evolution of a pathogen superrace are given for multilines of various compositions.Paper No. 9246 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, North Carolina. This investigation was supported in part by NIH Research Grant No. GM 11546 from the National Institute of General Medical Sciences 相似文献
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Glucose metabolism and insulin secretion were studied in isolated rat pancreatic islets of different sizes and the amount of tissue was quantitated by the measurement of DNA. It was found that larger islets (140-210 ng DNA/islet) utilized more glucose (based on the conversion of 3H-5-glucose to [3H]20) per ng of DNA than islets containing less DNA (60-120 ng/islet). However, the insulin secreted per ng of DNA in response to a given glucose concentration was the same in islets of all sizes. Also, the islet insulin and glucagon content when expressed in terms of DNA did not depend upon islet size. Thus, although glucose utilization rates expressed as a function of islet DNA content were greater in larger islets, no such relationship was found for glucose-induced insulin release or insulin and glucagon content. 相似文献