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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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Erik J. Szkokan‐Emilson Brian W. Kielstra Shelley E. Arnott Shaun A. Watmough John M. Gunn Andrew J. Tanentzap 《Global Change Biology》2017,23(1):117-126
Aquatic ecosystems depend on terrestrial organic matter (tOM) to regulate many functions, such as food web production and water quality, but an increasing frequency and intensity of drought across northern ecosystems is threatening to disrupt this important connection. Dry conditions reduce tOM export and can also oxidize wetland soils and release stored contaminants into stream flow after rainfall. Here, we test whether these disruptions to terrestrial–aquatic linkages occur during mild summer drought and whether this affects biota across 43 littoral zone sites in 11 lakes. We use copper (Cu) and nickel (Ni) as representative contaminants, and measure abundances of Hyalella azteca, a widespread indicator of ecosystem condition and food web production. We found that tOM concentrations were reduced but correlations with organic soils (wetlands and riparian forests) persisted during mild drought and were sufficient to suppress labile Cu concentrations. Wetlands, however, also became a source of labile Ni to littoral zones, which was linked to reduced abundances of the amphipod H. azteca, on average by up to 70 times across the range of observed Ni concentrations. This reveals a duality in the functional linkage of organic soils to aquatic ecosystems whereby they can help buffer the effects of hydrologic disconnection between catchments and lakes but at the cost of biogeochemical changes that release stored contaminants. As evidence of the toxicity of trace contaminant concentrations and their global dispersion grows, sustaining links among forests, organic soils and aquatic ecosystems in a changing climate will become increasingly important. 相似文献
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Maria B. Olsen Gunn A. Hildrestrand Katja Scheffler Leif Erik Vinge Katrine Alfsnes Vuk Palibrk Junbai Wang Christine G. Neurauter Luisa Luna Jostein Johansen Jonas D.S. Øgaard Ingrid K. Ohm Geir Slupphaug Anna Kuśnierczyk Arnt E. Fiane Sverre-Henning Brorson Lili Zhang Lars Gullestad Alexandra V. Finsen 《Cell reports》2017,18(1):82-92