BACKGROUND: Although coronary heart disease (CHD) is one of the major cardiovascular diseases, risk factors associated with the health-related quality of life (HRQoL) of CHD patients remain unclear. The present study was designed to determine the profile and significant factors of the HRQoL in CHD patients.
METHODS: A cross-sectional study was conducted in rural communities of Fangshan District, Beijing, China. Socio-demographic, lifestyle, and comorbidity information of CHD patients were collected by a structured questionnaire and medical records. HRQoL was measured using European Quality of Life 5-dimensions (EQ-5D) scale and EQ Visual Analog Scale (EQ-VAS). Multiple linear and logistic regressions were performed to explore the association of potential risk factors with HRQoL scores and each EQ-5D, respectively.
RESULTS: Totally, 1928 CHD patients (mean age 61.64 ± 9.24 years; female:male = 2.4:1) were enrolled in the study. The mean score of EQ-5D index and EQ-VAS were 0.889 ± 0.172 and 71.56 ± 17.65, respectively. Multiple linear regression revealed that marital status, physical activity, moderate alcohol drinking, and family's population were positive independent correlates of EQ-VAS, whereas diabetes mellitus and stroke were negative independent correlates (all P < 0.05). Age and stroke were negatively while physical activity, moderate alcohol drinking, family's population and household income were positively correlated with EQ-5D index (all P < 0.05) independently. In addition, each of the five HRQoL dimensions had various specific determinants, including obesity, underweight, smoking or education.
CONCLUSIONS: Findings of the study highlight certain socio-demographic, lifestyle factors, and comorbid stroke or diabetes mellitus as correlates of HRQoL in Chinese CHD patients. Large-scale cohort studies should be carried out to confirm our results in the future.
Background: Although coronary heart disease (CHD) is one of the major cardiovascular diseases, risk factors associated with the health-related quality of life (HRQoL) of CHD patients remain unclear. The present study was designed to determine the profile and significant factors of the HRQoL in CHD patients. Methods: A cross-sectional study was conducted in rural communities of Fangshan District, Beijing, China. Socio-demographic, lifestyle, and comorbidity information of CHD patients were collected by a structured questionnaire and medical records. HRQoL was measured using European Quality of Life 5-dimensions (EQ-5D) scale and EQ Visual Analog Scale (EQ-VAS). Multiple linear and logistic regressions were performed to explore the association of potential risk factors with HRQoL scores and each EQ-5D, respectively. Results: Totally, 1928 CHD patients (mean age 61.64 +/- 9.24 years; female:male = 2.4:1) were enrolled in the study. The mean score of EQ-5D index and EQ-VAS were 0.889 +/- 0.172 and 71.56 +/- 17.65, respectively. Multiple linear regression revealed that marital status, physical activity, moderate alcohol drinking, and familys population were positive independent correlates of EQ-VAS, whereas diabetes mellitus and stroke were negative independent correlates (all P < 0.05). Age and stroke were negatively while physical activity, moderate alcohol drinking, familys population and household income were positively correlated with EQ-5D index (all P < 0.05) independently. In addition, each of the five HRQoL dimensions had various specific determinants, including obesity, underweight, smoking or education. Conclusions: Findings of the study highlight certain socio-demographic, lifestyle factors, and comorbid stroke or diabetes mellitus as correlates of HRQoL in Chinese CHD patients. Large-scale cohort studies should be carried out to confirm our results in the future.
Here we compare volatile organic compound (VOC) measurements using a standard proton-transfer-reaction quadrupole mass spectrometer (PTR-QMS) with a new proton-transfer-reaction time of flight mass spectrometer (PTR-TOF) during the Uintah Basin Winter Ozone Study 2013 (UBWOS2013) field experiment in an oil and gas field in the Uintah Basin, Utah. The PTR-QMS uses a quadrupole, which is a mass filter that lets one mass to charge ratio pass at a time, whereas the PTR-TOF uses a time of flight mass spectrometer, which takes full mass spectra with typical 0.1 s-1 min integrated acquisition times. The sensitivity of the PTR-QMS in units of counts per ppbv (parts per billion by volume) is about a factor of 10-35 times larger than the PTR-TOF, when only one VOC is measured. The sensitivity of the PTR-TOF is mass dependent because of the mass discrimination caused by the sampling duty cycle in the orthogonal-acceleration region of the TOF. For example, the PTR-QMS on mass 33 (methanol) is 35 times more sensitive than the PTR-TOF and for masses above 120 amu less than 10 times more. If more than 10-35 compounds are measured with PTR-QMS, the sampling time per ion decreases and the PTR-TOF has higher signals per unit measuring time for most masses. For UBWOS2013 the PTR-QMS measured 34 masses in 37 s and on that timescale the PTR-TOF is more sensitive for all masses. The high mass resolution of the TOF allows for the measurements of compounds that cannot be separately detected with the PTR-QMS, such as oxidation products from alkanes and cycloalkanes emitted by oil and gas extraction. PTR-TOF masses do not have to be preselected, allowing for identification of unanticipated compounds. The measured mixing ratios of the two instruments agreed very well (R-2 >= 0.92 and within 20 %) for all compounds and masses monitored with the PTR-QMS.
For closed quantum systems driven away from equilibrium, work is often defined in terms of projective measurements of initial and final energies. This definition leads to statistical distributions of work that satisfy nonequilibrium work and fluctuation relations. While this two-point measurement definition of quantum work can be justified heuristically by appeal to the first law of thermodynamics, its relationship to the classical definition of work has not been carefully examined. In this paper, we employ semiclassical methods, combined with numerical simulations of a driven quartic oscillator, to study the correspondence between classical and quantal definitions of work in systems with 1 degree of freedom. We find that a semiclassical work distribution, built from classical trajectories that connect the initial and final energies, provides an excellent approximation to the quantum work distribution when the trajectories are assigned suitable phases and are allowed to interfere. Neglecting the interferences between trajectories reduces the distribution to that of the corresponding classical process. Hence, in the semiclassical limit, the quantum work distribution converges to the classical distribution, decorated by a quantum interference pattern. We also derive the form of the quantum work distribution at the boundary between classically allowed and forbidden regions, where this distribution tunnels into the forbidden region. Our results clarify how the correspondence principle applies in the context of quantum and classical work distributions and contribute to the understanding of work and nonequilibrium work relations in the quantum regime.
In addition to surface plasmon polaritons (SPPs), quasi-cylindrical waves (CWs) are also important components of electromagnetic fields on metal surfaces. In this study, we present a closed-form expression for CW fields on a dielectric-film-coated metal surface. It is found that the effective refractive index of CWs roughly keeps unchanged when the coated dielectric film becomes thicker, while the effective refractive index of SPPs increases rapidly. These different responses are explained by referring to a waveguide perspective, in which the SPP and CW waves are, respectively, identified as a waveguide mode and superposition of radiation modes. The results and related analyses with the waveguide perspective explicitly show the different physical natures of SPPs and CWs. (C) 2015 Optical Society of America
Tao S, Fang J, Zhao X, Zhao S, Shen H, Hu H, Tang Z, Wang Z, Guo Q. Rapid loss of lakes on the Mongolian Plateau. Proceedings of the National Academy of SciencesProceedings of the National Academy of Sciences. 2015;112:2281-2286.Abstract
Lakes are widely distributed on the Mongolian Plateau and, as critical water sources, have sustained Mongolian pastures for hundreds of years. However, the plateau has experienced significant lake shrinkage and grassland degradation during the past several decades. To quantify the changes in all of the lakes on the plateau and the associated driving factors, we performed a satellite-based survey using multitemporal Landsat images from the 1970s to 2000s, combined with ground-based censuses. Our results document a rapid loss of lakes on the plateau in the past decades: the number of lakes with a water surface area >1 km2 decreased from 785 in the late 1980s to 577 in 2010, with a greater rate of decrease (34.0%) in Inner Mongolia of China than in Mongolia (17.6%). This decrease has been particularly pronounced since the late 1990s in Inner Mongolia and the number of lakes >10 km2 has declined by 30.0%. The statistical analyses suggested that in Mongolia precipitation was the dominant driver for the lake changes, and in Inner Mongolia coal mining was most important in its grassland area and irrigation was the leading factor in its cultivated area. The deterioration of lakes is expected to continue in the following decades not only because of changing climate but also increasing exploitation of underground mineral and groundwater resources on the plateau. To protect grasslands and the indigenous nomads, effective action is urgently required to save these valuable lakes from further deterioration.
This paper studies an economy inhabited by overlapping generations of households and investors, with the only difference between the two being that households derive utility from housing services, whereas investors do not. Tight collateral constraint limits the borrowing capacity of households and drives the equilibrium interest rate level down to the housing price growth rate, which makes housing attractive as a store of value for investors. A housing bubble arises in an equilibrium in which investors hold houses for resale purposes only and without the expectation of receiving a dividend either in terms of utility or in terms of rent. Pension reform that reduces the contribution rate may increase the supply of credit and create the housing bubble. Empirical findings from China are consistent with theoretical predictions. Copyright Springer-Verlag Berlin Heidelberg 2015
It remains unclear whether dicofol should be defined as a persistent organic pollutant. Its environmental persistence has gained attention. This study focused on its degradation by cellulase. Cellulase was separated using a gel chromatogram, and its degradation activity towards dicofol involved its endoglucanase activity. By analyzing the kinetic parameters of cellulase reacting with mixed substrates, it was shown that cellulase reacted on dicofol and carboxyl methyl cellulose through two different active centers. Thus, the degradation of dicofol was shown to be an oxidative process by cellulase. Next, by comparing the impacts of tert-butyl alcohol (a typical OH free-radical inhibitor) on the removal efficiencies of dicofol under both cellulase and Fenton reagent systems, it was shown that the removal of dicofol was initiated by OH free radicals produced by cellulase. Finally, 4,4′-dichloro-dibenzophenone and chloride were detected using gas chromatography mass spectrometry and ion chromatography analysis, which supported our hypothesis. The reaction mechanism was analyzed and involved an attack by OH free radicals at the orthocarbon of dicofol, resulting in the degradation product 4,4′-dichloro-dibenzophenone.
As a class of brown carbon, organonitrogen compounds originating from the heterogeneous uptake of NH3 by secondary organic aerosol (SOA) have received significant attention recently. In the current work, particulate organonitrogen formation during the ozonolysis of alpha-pinene and the OH oxidation of m-xylene in the presence of ammonia (34-125 ppb) was studied in a smog chamber equipped with a high resolution time-of-flight aerosol mass spectrometer and a quantum cascade laser instrument. A large diversity of nitrogen-containing organic (NOC) fragments was observed which were consistent with the reactions between ammonia and carbonyl-containing SOA. Ammonia uptake coefficients onto SOA which led to organonitrogen compounds were reported for the first time, and were in the range of similar to 10(-3)-10(-2), decreasing significantly to <10(-5) after 6 h of reaction. At the end of experiments (similar to 6 h) the NOC mass contributed 8.9 +/- 1.7 and 31.5 +/- 4.4 wt% to the total alpha-pineneand m-xylene-derived SOA, respectively, and 4-15 wt% of the total nitrogen in the system. Uptake coefficients were also found to be positively correlated with particle acidity and negatively correlated with NH3 concentration, indicating that heterogeneous reactions were responsible for the observed NOC mass, possibly limited by liquid phase diffusion. Under these conditions, the data also indicate that the formation of NOC can compete kinetically with inorganic acid neutralization. The formation of NOC in this study suggests that a significant portion of the ambient particle associated N may be derived from NH3 heterogeneous reactions with SOA. NOC from such a mechanism may be an important and unaccounted for source of PM associated nitrogen. This mechanism may also contribute to the medium or long-range transport and wet/dry deposition of atmospheric nitrogen.
As the fast development of ultra-short ultra-intense laser technology and mechanism research of laser ion acceleration, laser-driven ion accelerators have drawn a lot of attention for the past decades. Thomson spectrometer is one of the critical diagnostics for laser-driven ion acceleration, because of its ability to measure ions' energy spectrum, charge, and charge-to-mass radio parameters simultaneously. This paper presents a compact real-time single-shot Thomson spectrometer, which uses electromagnetic field to disperse ions and scintillator coupled with high performance EMCCD as a record medium. The spectrometer has a pair of inclined electric plates with the advantage of avoiding electromagnetic noise caused by low energy ions' collision with electric plates, improving signal-to-noise ratio accordingly. Experiments were carried out on two conventional accelerators in Peking University to test the spectrometer and measure detection efficiency of ions at the same time. It turns out that the spectrometer can be used for detection of ions driven by 100 TW class femtosecond laser system, and will contribute to our understanding of laser-based high energy density physics.介绍一种使用闪烁体耦合电子倍增电荷耦合器件(EMCCD)的方式对离子进行记录的汤姆逊能谱仪,可实现对离子能谱的实时单发测量。同时,该谱仪利用倾斜 电极板对离子进行偏转,可减少由于离子打在电极板上产生的电磁噪声,能够提高实验结果的信噪比。该谱仪在北京大学4.5 MV静电加速器和2*6 MV串列加速器上进行了标定实验,测量了闪烁体将离子转化成光子后的探测效率,实验结果也验证了该谱仪的可行性和稳定性。该汤姆逊谱仪将用于北京大学激光 加速器CLAPA对离子束流的测量研究。