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Lauren Porter Jennifer Duke Meredith Hennon David Dekevich Erik Crankshaw Ghada Homsi Matthew Farrelly 《PloS one》2015,10(5)
Recent youth trends in the prevalence of e-cigarette and traditional cigarette use in Florida were examined in a cross-sectional, representative state sample from 2011 to 2014. Traditional cigarette use among youth declined during the study period. Experimentation with and past 30-day use of e-cigarettes among Florida youth tripled over 4 years. Past 30-day e-cigarette use exceeded traditional cigarette use in 2014; 10.8% of high school and 4.0% of middle school students reported recent e-cigarette use, compared with 8.7% of high school and 2.9% of middle school students for traditional cigarettes (P<0.001). By 2014, 20.5% of high school and 8.5% of middle school students reported ever use of e-cigarettes. Among ever e-cigarette users in 2014, 30.3% of high school and 42.2% of middle school students had never smoked traditional cigarettes. Given the concern that significant rates of e-cigarette use by U.S. adolescents may have a negative effect on public health, further review of e-cigarette advertising, marketing, sales, and use among U.S. youth is warranted. 相似文献
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Ami Klein Sharon Ramcharitar Nevena Christeff Erik Nisbett-Brown Emmanuel Nunez Aaron Malkin 《In vitro cellular & developmental biology. Animal》1991,27(4):307-311
Summary These authors attempted to test the effect of anticoagulants on lymphocytes viability by reproducing the procedure used for
lymphocyte isolation for various immunologic tests in which blood specimens are allowed to stay at room temperature for 2
h before lymphocytes are isolated. Blood was obtained with three different anticoagulants i.e. heparin, citrate, and CPDA
(citrate, phosphate, dextrose, and adenine). Plasma was lyophilized and extracted with ethanol. Dried ethanol extracts were
suspended in medium (RPMI 1640+10% fetal bovine serum) and incubated with a lymphocyte cell line (MOLT-4). After 24 h of incubation
the viability of cells was examined. The following death rates of the cells were observed: heparin −63±4.6% (mean±SEM), citrate
−27±6.7%, and CPDA 6.2±0.6% (P<0.0005). A significant correlation was found between these results and changes in the concentrations of free fatty acids
in the extracts. These results emphasize the importance of choosing the right anticoagulant when the viability of lymphocytes
is obligatory. 相似文献
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Frankia is the diverse bacterial genus that fixes nitrogen within root nodules of actinorhizal trees and shrubs. Systematic and ecological
studies of Frankia have been hindered by the lack of morphological, biochemical, or other markers to readily distinguish strains. Recently,
nucleotide sequence of 16 S RNA from the small ribosomal subunit has been used to classify and identify a variety of microorganisms.
We report nucleotide sequences from portions of the 16 S ribosomal RNA from Frankia strains AcnI1 isolated from Alnus viridis ssp. crispa (Ait.) Turrill and PtI1 isolated from Purshia tridentata (Pursh) DC. The number of nucleotide base substitutions and gaps we find more than doubles the previously reported sequence
diversity for the same variable regions within other strains of Frankia. 相似文献
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We sought to determine whether the orexigenic hormone, ghrelin, is involved in the intrinsic regulation of food choice in rats. Ghrelin would seem suited to serve such a role given that it signals hunger information from the stomach to brain areas important for feeding control, including the hypothalamus and reward system (e.g. ventral tegmental area, VTA). Thus, in rats offered a choice of palatable foods (sucrose pellets and lard) superimposed on regular chow for 2 weeks, we explored whether acute central delivery of ghrelin (intracerebroventricular (ICV) or intra-VTA) is able to redirect their dietary choice. The major unexpected finding is that, in rats with high baseline lard intake, acute ICV ghrelin injection increased their chow intake over 3-fold, relative to vehicle-injected controls, measured at both 3 hr and 6 hr after injection. Similar effects were observed when ghrelin was delivered to the VTA, thereby identifying the VTA as a likely contributing neurobiological substrate for these effects. We also explored food choice after an overnight fast, when endogenous ghrelin levels are elevated, and found similar effects of dietary choice to those described for ghrelin. These effects of fasting on food choice were suppressed in models of suppressed ghrelin signaling (i.e. peripheral injection of a ghrelin receptor antagonist to rats and ghrelin receptor (GHSR) knock-out mice), implicating a role for endogenous ghrelin in the changes in food choice that occur after an overnight fast. Thus, in line with its role as a gut-brain hunger hormone, ghrelin appears to be able to acutely alter food choice, with notable effects to promote “healthy” chow intake, and identify the VTA as a likely contributing neurobiological substrate for these effects. 相似文献