Polycyclic aromatic hydrocarbons (PAHs) belong to a class of ubiquitous pollutants and are possibly associated with adverse health effects. In this study, we aimed to assess PAH exposure by measuring the hydroxylated metabolites (hydroxy-PAHs) in urine samples of a rural population from the North China Plain and to explore the possible associations between PAH exposure and oxidative stress indicated by urinary malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG). High levels of urinary hydroxy-PAHs were observed, with the geometric mean concentrations of 0.57, 2.2, 5.0, 7.0, and 16.6 mu g g(-1) creatinine for 1-hydroxypyrene, hydroxyphenanthrenes, hydroxyfluorenes, hydroxybiphenyls, and hydroxynaphthalenes, respectively. Particularly in the winter season, the exposures were 2.3-6.0-fold of those in the spring. Corresponding to PAH exposure, levels of urinary MDA were positively associated with hydroxy-PAHs after controlling for confounders in the linear regression models (p < 0.05). An estimation indicated 21.3-39.3 % increment of urinary MDA per one-fold increase of hydroxy-PAHs. In contrast, no significant correlation was found between urinary 8-OHdG and hydroxy-PAHs; alternatively, living at the e-waste recycling site was found a significant factor on this oxidative DNA damage. These results provide evidence on high PAH exposure and the induction of oxidative stress on lipid peroxidation for this rural population.
How geographical neighboring competitors influence the strategic price behaviors of universities is still unclear because previous studies assume spatial independence between universities. Using data from the National Center for Education Statistics college navigator dataset, this study shows that the price of one university is spatially autocorrelated to its neighboring competitors and such neighborhood structure induces cooperation Nash equilibrium in a spatial price game. In the spatial price game of universities the possibility of the cooperation solution is about 76%, while that of the defeat solution is about 24%. This study demonstrates that the relation between price difference and geographical distance of universities is an inverse U-shaped curve rather than a line.
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 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.