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- Maxwell, Karen L., et al.
(författare)
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Protein folding : Defining a "standard" set of experimental conditions and a preliminary kinetic data set of two-state proteins
- 2005
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Ingår i: Protein Science. - : Wiley. - 0961-8368 .- 1469-896X. ; 14, s. 602-16
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Tidskriftsartikel (refereegranskat)abstract
- Recent years have seen the publication of both empirical and theoretical relationships predicting the rates with which proteins fold. Our ability to test and refine these relationships has been limited, however, by a variety of difficulties associated with the comparison of folding and unfolding rates, thermodynamics, and structure across diverse sets of proteins. These difficulties include the wide, potentially confounding range of experimental conditions and methods employed to date and the difficulty of obtaining correct and complete sequence and structural details for the characterized constructs. The lack of a single approach to data analysis and error estimation, or even of a common set of units and reporting standards, further hinders comparative studies of folding. In an effort to overcome these problems, we define here a "consensus" set of experimental conditions (25°C at pH 7.0, 50 mM buffer), data analysis methods, and data reporting standards that we hope will provide a benchmark for experimental studies. We take the first step in this initiative by describing the folding kinetics of 30 apparently two-state proteins or protein domains under the consensus conditions. The goal of our efforts is to set uniform standards for the experimental community and to initiate an accumulating, self-consistent data set that will aid ongoing efforts to understand the folding process.
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| 2. |
- Yang, Ya, et al.
(författare)
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Human exposure to phthalate esters via ingestion of municipal drinking water from automatic water purifiers : levels, sources, and risks
- 2022
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Ingår i: Environmental Science. - : Royal Society of Chemistry. - 2053-1400 .- 2053-1419. ; 8:12, s. 2843-2855
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Tidskriftsartikel (refereegranskat)abstract
- The presence of organic pollutants in drinking water is an environmental problem threatening public health. Water purifiers are commonly recognized as effective purification equipment for drinking water and are thus prevalent in the market, so there is a need to assess their true effects on drinking water. In this study, we have analyzed the distribution, potential sources, and health risks of phthalate esters (PAEs) in tap as well as purified water. 7 out of 22 target PAEs have been detected in a total of 75 drinking water samples, including tap water (TW), water vending machines (WVMs), and water boiling machines (WBMs). The total concentrations of 22 PAEs are N.D. to 447 ng L-1 in TW samples, 25.7 to 1.10 x 10(3) ng L-1 in WBM water, and N.D. to 841 ng L-1 in WVM water. The concentrations of PAEs in most WVM and WBM samples were comparable or slightly higher than those in TW samples. Meanwhile, the sigma PAE concentrations in the nearshore of the Yangtze Estuary area (northern and southern areas) were slightly higher than those from offshore areas (Pudong: PD, Fengxian and Minhang: FM), which may be attributed to the source water. Combining the results of principal component analysis and correlation analysis, certain PAEs, e.g., diisobutyl phthalate (DIBP), dibuthyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP), were more polluting than diethyl phthalate (DEP) and di-methyl phthalate (DMP) in WVM water than those in TW samples. This work suggests that the application of water purifiers may not remove certain PAEs efficiently from drinking water. In addition, the estimated daily intakes (EDIs) of sigma PAE via drinking water from automatic water purifiers were 2-3 times those from tap water under a high-exposure scenario, but all EDIs are well below current health regulatory guidelines for PAEs. This survey indicates that water purifiers made nearly no decrease to the PAE concentrations and possibly have negative effects on the quality of drinking water.
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