Apparent change of the 3C/3D line intensity ratio in neonlike ions.

The resonance 3C ([(2p5)1/23d3/2]J=1 → [2p6]J=0) to intercombination 3D ([(2p5)3/23d5/2]J=1 → [2p6]J=0) line intensity ratio of neonlike ions has been studied. The measured line intensity ratio for neonlike Xe44+ ions shows an apparent change, which is reproduced by the calculations using the relativistic configuration interaction plus many-body perturbation theory. It is clearly elucidated that the change in the 3C/3D line intensity ratio is caused by strong configuration mixing between the upper levels of the 3D and 3F ([(2p5)1/23s]J=1 → [2p6]J=0) lines. The present measurement allows us to discuss the 3C/3D line intensity ratio for the highest-Z ions hitherto, which suggests that the experiment-theory discrepancy in the 3C/3D line intensity ratio of neonlike ions diminishes with increasing atomic number Z and further trends to vanish at higher-Z ions. Furthermore, the present study provides benefits to better understand configuration mixing effect in the radiative opacity of hot plasmas.

The Annual Economic Burden of Syphilis: An Estimation of Direct, Productivity, and Intangible Costs for Syphilis in Guangdong Initiative for Comprehensive Control of Syphilis Sites.

BACKGROUND: Syphilis has continuously posed a great challenge to China. However, very little data existed regarding the cost of syphilis. Taking Guangdong Initiative for Comprehensive Control of Syphilis area as the research site, we aimed to comprehensively measure the annual economic burden of syphilis from a societal perspective. METHODS: Newly diagnosed and follow-up outpatient cases were investigated by questionnaire. Reported tertiary syphilis cases and medical institutions cost were both collected. The direct economic burden was measured by the bottom-up approach, the productivity cost by the human capital method, and the intangible burden by the contingency valuation method. RESULTS: Three hundred five valid early syphilis cases and 13 valid tertiary syphilis cases were collected in the investigation to estimate the personal average cost. The total economic burden of syphilis was US $729,096.85 in Guangdong Initiative for Comprehensive Control of Syphilis sites in the year of 2014, with medical institutions cost accounting for 73.23% of the total. Household average direct cost of early syphilis was US $23.74. Average hospitalization cost of tertiary syphilis was US $2,749.93. Of the cost to medical institutions, screening and testing comprised the largest proportion (26%), followed by intervention and case management (22%) and operational cost (21%). Household average productivity cost of early syphilis was US $61.19. Household intangible cost of syphilis was US $15,810.54. CONCLUSIONS: Syphilis caused a substantial economic burden on patients, their families, and society in Guangdong. Household productivity and intangible costs both shared positive relationships with local economic levels. Strengthening the prevention and effective treatment of early syphilis could greatly help to lower the economic burden of syphilis.

Attitudes of consumers and live-poultry workers to central slaughtering in controlling H7N9: a cross-sectional study.

BACKGROUND: Guangdong Province in the Pearl River Delta of Southeast China is among the areas in the country with the highest rates of avian flu cases. In order to control the outbreak of human-infected H7N9 cases, Guangdong launched a new policy on the central slaughtering of live poultry in 2015. This study aims to evaluate attitudes of consumers and live-poultry workers toward the policy. The live-poultry workers consisted of two sub-groups: live-poultry traders and poultry farm workers. METHODS: Consumers and live-poultry workers from Guangdong were enrolled by stratified multi-stage random sampling. Online and field surveys were conducted to investigate participants' attitudes on policy implementation. Questionnaires were developed to quantify participant demographics, to collect information about attitudes toward the policy, and to identify influential factors of policy acceptability. Proportional odds logistics regression was used in the univariate and multivariate analyses. A total of 1449 consumers, 181 live-poultry traders, and 114 poultry farm workers completed the study. RESULTS: Policy acceptability percentages among consumers, live-poultry traders, and poultry farm workers were 57.1, 37.9, and 62.6%, respectively. Logistics regression shows that consumers tended not to support the policy if they were males, if they were concerned with the food safety of chilled products, and if they preferred purchasing live poultry. Live-poultry traders tended not to support if they were subsidized by the government, if they were males, if they experienced a drop in trading volume, and if they were unclear whether avian flu was a preventable disease. Finally, poultry farm workers tended not to support if they experienced a drop in trading volume, if they operated a poultry farm on a small to medium scale, and if they experienced inconvenience in their work due to the policy. CONCLUSIONS: The study reveals a substantial refusal or slowness to accept the policy. Failure to accept the policy results from varying reasons. Among consumers, concern about food safety and dietary preference are two major causes of disapproval. Policy acceptability among live-poultry workers diverges within the two sub-groups. While a large percentage of poultry farm workers accept the policy, the drop in trading and an insufficient subsidy hamper acceptance by live-poultry traders. We recommend that policy-makers promote health education and alleviate the policy impact on trading with a reformed subsidy policy to increase acceptability. These findings are crucial for the prevention of human-infected H7N9 cases in Guangdong.

Attitudes towards suicide in urban and rural China: a population based, cross-sectional study.

BACKGROUND: Suicide intervention programs have been guided by findings that attitude towards suicide and suicidal behavior may be causally linked. These findings also make it imperative to identify the factors that influence attitudes towards suicide. However, there has been little research on attitudes towards suicide among the general population, especially in low-income and middle-income countries. This population-based, cross-sectional study investigated the associated factors of attitudes towards suicide among a representative sample of urban and rural adult residents in China. METHODS: A multi-stage, stratified random sampling approach was implemented to select participants. Data were collected by a survey using the Scale of Public Attitudes about Suicide (SPAS). The survey also collected some socio-demographic factors and suicidal history of participants. Statistical tests were conducted to identify associated factors that account for variations in attitudes towards suicide. RESULTS: The residents in China generally hold a neutral attitude towards suicide. Attitudes towards suicide among Chinese residents were associated with age, duration of formal education, marital status, job and suicidal ideation. Different attitudinal subscales seemed not to share the same risk factors. However, gender, ethnicity, religious belief, housing style and economic status might not influence residents' attitudes towards suicide. Attitudes towards suicide among Chinese urban and rural residents generally had no statistical difference with one notable exception: opinions on whether or not suicides and suicide attempts are different phenomena. CONCLUSIONS: Age, duration of formal education, marital status, job and suicidal ideation seem to have an impact on attitudes towards suicide among residents. Urban and rural residents have similar attitudes towards suicide with the only statistically significance difference being their opinions on whether or not suicides and suicide attempts are different phenomena.

General practitioners versus other physicians in the quality of primary care: a cross-sectional study in Guangdong Province, China.

BACKGROUND: The primary care in China can be provided by general practitioners (GPs) and other physicians (non-GPs). However, China's general practice system has never been really established. Chinese patients tend to consider the quality of primary care provided by GPs much lower than that of non-GPs. Besides, many GPs presently prefer leaving their own positions and seeking better development in big hospitals, which has made the already weak GP system weaker. Yet, few studies have specially compared the quality of primary care provided by Chinese GPs and other physicians and no studies have explored the independent predictors of Chinese GPs' intentions to stay on their current job. In this study, we aimed to compare the quality of primary care offered by GPs with non-GPs and to explore the independent predictors of GPs' future work intentions. METHODS: This cross-sectional study applied multi-stage random cluster sampling methodology. The data were collected from November 2013 to September 2014 in Guangdong Province. In total, 401 effective questionnaires were selected from the physicians. Quality of primary care was assessed using the Primary Care Assessment Tool (PCAT) Provider Part, representing six primary care domains: ongoing care, coordination (i.e., referrals and information systems), comprehensiveness (i.e., service available and service provided), family-centeredness, community orientation and cultural competence. RESULTS: Of 401 participating physicians, 163 (40.6 %) were GPs. The total PCAT score was 26.32 ± 2.24 which was the sum score of the six domains and represent the quality of primary care. GPs achieved significantly different total scores and scores on three individual scales: comprehensiveness: service available, comprehensiveness: service provided and community orientation. Multiple linear regressions revealed GPs had a higher total score and scores for comprehensiveness: service provided and community orientation after adjusting for sociodemographic characteristics. In addition, GPs were more likely to intend to stay in their current job in the coming year, and this was associated with their educational level. CONCLUSIONS: Our findings showed that GPs reported higher quality of primary care than other physicians, and were more inclined to stay in their current job. With more comprehensive care and community orientation provided by GPs, residents could reach basic medical cares and needn't to crowd into larger hospitals.

Isomerization Dynamics in the Symmetric and Asymmetric Fragmentation of Ethane Dications.

Hydrogen- or proton-migration-induced isomerization has recently been of concern for its critical role in the dissociation of organic molecules of astrophysical or biological relevance. Herein we present a combined experimental and theoretical study of the two-body C-C bond breakdown dissociation of ethane dication. For the asymmetric fragmentation channel CH2+ + CH4+, the kinetic energy release measurements and ab initio quantum chemical calculations demonstrate that the reaction pathway involving hydrogen-migration-induced isomerization of [CH3-CH3]2+ to [CH2-CH4]2+ can be accessed via the lowest triplet state rather than the ground singlet state of ethane dication. Interestingly, it is found that a considerable proportion of the yield of symmetric fragmentation CH3+ + CH3+, which is usually considered from a direct Coulomb explosion and seemingly independent of isomerization, could come from the dissociation of ethane dication in the ground singlet state with the involvement of [CH3-CH3]2+ isomerization to intermediate [H2C(H2)CH2]2+ of the diborane-like double-bridged structure.

Formation of H3+ from ethane dication induced by electron impact.

Hydrogen migration plays an important role in the chemistry of hydrocarbons which considerably influences their chemical functions. The migration of one or more hydrogen atoms occurring in hydrocarbon cations has an opportunity to produce the simplest polyatomic molecule, i.e. H3+. Here we present a combined experimental and theoretical study of H3+ formation dynamics from ethane dication. The experiment is performed by 300 eV electron impact ionization of ethane and a pronounced yield of H3+ + C2H3+ coincidence channel is observed. The quantum chemistry calculations show that the H3+ formation channel can be opened on the ground-state potential energy surface of ethane dication via transition state and roaming mechanisms. The ab initio molecular dynamics simulation shows that the H3+ can be generated in a wide time range from 70 to 500 fs. Qualitatively, the trajectories of the fast dissociation follow the intrinsic reaction coordinate predicted by the conventional transition state theory. The roaming mechanism, compared to the transition state, occurs within a much longer timescale accompanied by nuclear motion of larger amplitude.

A low-energy compact Shanghai-Wuhan electron beam ion trap for extraction of highly charged ions.

A low-energy, compact, and superconducting electron beam ion trap (the Shanghai-Wuhan EBIT or SW-EBIT) for extraction of highly charged ions is presented. The magnetic field in the central drift tube of the SW-EBIT is approximately 0.21 T produced by a pair of high-temperature superconducting coils. The electron-beam energy of the SW-EBIT is in the range of 30-4000 eV, and the maximum electron-beam current is up to 9 mA. Acting as a source of highly charged ions, the ion-beam optics for extraction is integrated, including an ion extractor and an einzel lens. A Wien filter is then used to measure the charge-state distribution of the extracted ions. In this work, the tungsten ions below the charge state of 15 have been produced, extracted, and analyzed. The charge-state distributions and spectra in the range of 530-580 nm of tungsten ions have been measured simultaneously with the electron-beam energy of 279 eV and 300 eV, which preliminarily indicates that the 549.9 nm line comes from W14+.

A portable high-resolution soft x-ray and extreme ultraviolet spectrometer designed for the Shanghai EBIT and the Shanghai low energy EBITs.

A portable high resolution soft x-ray and extreme ultraviolet (EUV) spectrometer has been developed for spectroscopic research at the Shanghai Electron Beam Ion Trap (EBIT) laboratory. A unique way of aligning the grazing incidence spectrometer using the zero order of the grating is introduced. This method is realized by extending the range of the movement of the CCD detector to cover the zero order. The alignment can be done in a few minutes, thus leading to a portable spectrometer. The high vacuum needed to be compatible with the EBITs is reached by mounting most of the translation and rotation stages outside the chamber. Only one high vacuum compatible linear guide is mounted inside the chamber. This is to ensure the convenient interchange of the gratings needed to enable wavelength coverage of the whole range of 10 to 500 Å. Spectra recorded with one of our low energy EBITs shows that a resolving power of above 800 can be achieved. In the slitless configuration used in this work, we found the resolving power to be limited by the width of the EBIT plasma. When mounted on the Shanghai EBIT which is a high energy EBIT and has a narrower EBIT plasma width, the estimated resolving power will be around 1400 at 221.15 Å.

M(F)-dependent lifetimes due to hyperfine induced interference effects.

We report on the first theoretical investigation of M(F)-dependent lifetimes due to interference between a magnetic octupole transition and a hyperfine induced electric quadrupole transition. Extensive multiconfiguration Dirac-Fock calculations are used to model the hyperfine quenching of the magnetic octupole decay of 3d(9)4s 3D3 and the state mixing between the 3D3 and 3D2 due to hyperfine interaction in nickel-like Xe26+.