Clay-humic complexes are commonly distributed in natural environments. They play very important roles in regulating the transport and retention of hydrophobic organic contaminants in soils and sediments. This study examined the structural changes of humic acid (HA) after adsorption by clay minerals and determined phenanthrene sorption by clay-humic complexes. Solid- and liquid-state 13C nuclear magnetic resonance (NMR), for the first time, provided direct evidence for HA fractionation during adsorption on mineral surfaces, that is, aliphatic fractions were preferentially adsorbed by clay minerals while aromatic fractions were left in the solution. The ratio of UV absorbance of HA at 465 and 665 nm (E4 to E6 ratio), which is related to aromaticity, corroborated with the NMR results. For both montmorillonite and kaolinite, adsorbed HA fractions had higher sorption linearity (N) and affinity (K(oc)) than the source HA. The K(oc) of adsorbed HA for the clay-humic complexes could be up to several times higher than that of the source HA. This large increase may be contributed by the low polarity of the bound HA. Moreover, for each mineral, the N values of adsorbed HA increased with increasing HA loading. It is believed that HA may develop a more condensed structure on mineral surface at lower HA loading level due to the stronger interactions between HA and mineral surface as a result of close contacts.

on behalf of the PARTNER InvestigatorsBackground-In patients with severe aortic stenosis who cannot have surgery, transcatheter aortic valve replacement (TAVR) has been shown to improve survival and quality of life compared with standard therapy, but the costs and cost-effectiveness of this strategy are not yet known. Methods and Results-The PARTNER trial randomized patients with symptomatic, severe aortic stenosis who were not candidates for surgery to TAVR (nϭ179) or standard therapy (nϭ179). Empirical data regarding survival, quality of life, medical resource use, and hospital costs were collected during the trial and used to project life expectancy, quality-adjusted life expectancy, and lifetime medical care costs to estimate the incremental cost-effectiveness of TAVR from a US perspective. For patients treated with TAVR, mean costs for the initial procedure and hospitalization were $42 806 and $78 542, respectively. Follow-up costs through 12 months were lower with TAVR ($29 289 versus $53 621) because of reduced hospitalization rates, but cumulative 1-year costs remained higher ($106 076 versus $53 621). We projected that over a patient's lifetime, TAVR would increase discounted life expectancy by 1.6 years (1.3 quality-adjusted life-years) at an incremental cost of $79 837. The incremental cost-effectiveness ratio for TAVR was thus estimated at $50 200 per year of life gained or $61 889 per quality-adjusted life-year gained. These results were stable across a broad range of uncertainty and sensitivity analyses. Conclusions-For patients with severe aortic stenosis who are not candidates for surgery, TAVR increases life expectancy at an incremental cost per life-year gained well within accepted values for commonly used cardiovascular technologies. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00530894.

on behalf of the Reduction of Atherothrombosis for Continued Health (REACH) Registry Investigators* Background-Peripheral artery disease (PAD) is common and imposes a high risk of major systemic and limb ischemic events. The REduction of Atherothrombosis for Continued Health (REACH) Registry is an international prospective registry of patients at risk of atherothrombosis caused by established arterial disease or the presence of Ն3 atherothrombotic risk factors. Methods and Results-We compared the 2-year rates of vascular-related hospitalizations and associated costs in US patients with established PAD across patient subgroups. Symptomatic PAD at enrollment was identified on the basis of current intermittent claudication with an ankle-brachial index (ABI) Ͻ0.90 or a history of lower-limb revascularization or amputation. Asymptomatic PAD was diagnosed on the basis of an enrollment ABI Ͻ0.90 in the absence of symptoms. Overall, 25 763 of the total 68 236 -patient REACH cohort were enrolled from US sites; 2396 (9.3%) had symptomatic and 213 (0.8%) had asymptomatic PAD at baseline. One-and cumulative 2-year follow-up data were available for 2137 (82%) and 1677 (64%) of US REACH patients with either symptomatic or asymptomatic PAD, respectively. At 2 years, mean cumulative hospitalization costs, per patient, were $7445, $7000, $10 430, and $11 693 for patients with asymptomatic PAD, a history of claudication, lower-limb amputation, and revascularization, respectively (Pϭ0.007). A history of peripheral intervention (lower-limb revascularization or amputation) was associated with higher rates of subsequent procedures at both 1 and 2 years. Conclusions-The economic burden of PAD is high. Recurring hospitalizations and repeat revascularization procedures suggest that neither patients, physicians, nor healthcare systems should assume that a first admission for a lower-extremity PAD procedure serves as a permanent resolution of this costly and debilitating condition. (Circ Cardiovasc Qual Outcomes. 2010;3:642-651.)

In high-risk patients with severe AS, health status improved substantially between baseline and 1 year after either TAVR or AVR. TAVR via the transfemoral, but not the transapical route, was associated with a short-term advantage compared with surgery. (Placement of AoRTic TraNscathetER Valve [PARTNER] trial; NCT00530894).

BackgroundMyopia is the leading cause of preventable blindness in children and young adults. Multiple epidemiological studies have confirmed a high prevalence of myopia in Asian countries. However, fewer longitudinal studies have been performed to evaluate the secular changes in the prevalence of myopia, especially high myopia in China. In the present study, we investigated trends in the prevalence of myopia among high school students in Fenghua city, eastern China, from 2001 to 2015.MethodsThis was a population-based, retrospective study. Data were collected among 43,858 third-year high school students. Noncycloplegic autorefraction was used to determine refractive error, which was defined as low myopia, moderate myopia, high myopia and very high myopia according to the spherical equivalent from the worse eye of each participant. The prevalence of myopia was calculated and the annual percentage change (APC) was used to quantify the time trends. All analyses were conducted using the SPSS, Stata and Graphpad Prism software.ResultsFrom 2001 to 2015, the prevalence of overall myopia increased from 79.5% to 87.7% (APC =0.59%), with a significant increase of moderate myopia (38.8% to 45.7%, APC = 0.78%), high myopia (7.9% to 16.6%, APC = 5.48%) and very high myopia (0.08% to 0.92%, APC = 14.59%), while the prevalence of low myopia decreased from 32.7% to 24.4% (APC = − 1.73%). High myopia and very high myopia contributed the major part of the increasing trend of myopia prevalence (contribution rate 27.00% and 69.07%, respectively).ConclusionsDuring the 15-year period, there was a remarkable increase in the prevalence of high and very high myopia among high school students, which might become a serious public health problem in China for the next few decades.Electronic supplementary materialThe online version of this article (10.1186/s12886-018-0829-8) contains supplementary material, which is available to authorized users.