[Photochemical Mechanism and Control Strategy Optimization for Summertime Ozone Pollution in Yining City].

To explore the formation mechanism of the ozone （O3） and emission reduction strategy in a northwestern city， an extensive field campaign was conducted in summertime in 2021 in Yining City， in which the 0-D box model incorporating the latest explicit chemical mechanism （MCMv3.3.1） was applied for the first time to quantify the O3-NOx-VOCs sensitivity and formulate a precise O3 control strategy in this city. The results showed that： ① the three indicators ï¼»i.e.， O3 formation potential （OFP）， ·OH reaction rate （k·OH）， and relative incremental reactivity （RIR）］ jointly indicated that alkenes， oxygenated volatile organic compounds （OVOCs）， and aromatics were the highest contributors among anthropogenic volatile organic compounds （AVOC） to O3 formation， and the contribution of biogenic volatile organic compounds （BVOC） also could not be ignored. Additionally， the results based on RIR calculation implied that that the acetaldehyde， ethylene， and propylene were the most sensitive individual VOCs species in Yining City. ② The in-situ photochemical O3 variations were primarily influenced by the local photochemical production and export process horizontally to downwind areas or vertically to the upper layer， and the reaction pathways of HO2·+ NO and ·OH + NO2 contributed the most to the gross Ox photochemical production （60%） and photochemical destruction production （53%）， respectively. Hence， the reduction in local emissions for O3 precursors was more essential to alleviate O3 pollution in this city. ③ The outcome based on RIR（NOx） / RIR（AVOC） and EKMA jointly suggested that the photochemical regime in this city can be considered a transitional regime that was also nearly a VOCs-limited regime. Detailed mechanism modeling based on multiple scenarios further suggested that the NOx and VOCs synergic emission reduction strategies was helpful to alleviate O3 pollution. These results are useful to provide policy-related guidance for other cities facing similar O3 pollution in northwest China.

Light scattering of a uniform uniaxial anisotropic sphere by an on-axis high-order Bessel vortex beam.

Analytical solutions to the scattering of a uniform uniaxial anisotropic sphere illuminated by an on-axis high-order Bessel vortex beam (HOBVB) are investigated. Using the vector wave theory, the expansion coefficients of the incident HOBVB in terms of the spherical vector wave functions (SVWFs) are obtained. According to the orthogonality of the associated Legendre function and exponential function, more concise expressions of the expansion coefficients are derived. It can reinterpret the incident HOBVB faster compared with the expansion coefficients of double integral forms. The internal fields of a uniform uniaxial anisotropic sphere are proposed in the integrating form of the SVWFs by introducing the Fourier transform. The differences of scattering characteristics of a uniaxial anisotropic sphere illuminated by a zero-order Bessel beam, Gaussian beam, and HOBVB are exhibited. Influences of the topological charge, conical angle, and particle size parameters on the angle distributions of the radar cross section are analyzed in detail. The scattering and extinction efficiencies varied with the particle radius, conical angle, permeability, and dielectric anisotropy are also discussed. The results provide insights into the scattering and light-matter interactions and may find important applications in optical propagation and optical micromanipulation of biological and anisotropic complex particles.

[Photochemical Mechanism and Control Strategy Optimization for Summertime Ozone Pollution in an Industrial City in the North China Plain].

To investigate the characteristics and formation mechanism of ozone (O3) pollution in an industrial city, an extensive one-month field campaign focusing on O3 and its precursors (e.g., volatile organic compounds[VOC] and nitrogen oxides[NOx]) was conducted in Zibo City, a highly industrializd city in the North China Plain, in June 2021. The 0-D box model incorporating the latest explicit chemical mechanism (MCMv3.3.1) was applied using an observation dataset (e.g., VOC, NOx, HONO, and PAN) as model contraints to explore the optimal reduction strategy for O3 and its precursors. The results showed that ① during high-O3 episodes, stagnant weather conditions with high temperature and solar radiation as well as low relative humidity were observed, and oxygenated VOCs and alkenes from anthropogenic VOCs contributed the most to the total ozone formation potential and OH reactivity (k·OH). ② The in-situ O3 variation was primarily affected by local photochemical production and export process horizontal to downwind areas or vertical to the upper layer. The reduction in local emissions was essential to alleviate O3 pollution in this region. ③ During high-O3 episodes, high concentrations of ·OH (10×106 cm-3) and HO2· (14×108 cm-3) radical drove and generated a high O3 production rate (daytime peak value reached 36×10-9 h-1). The reaction pathways of HO2·+NO and ·OH+NO2 contributed the most to the in-situ gross Ox photochemical production (63%) and photochemical destruction (50%), respectively. ④ Compared to those during low-O3 episodes, the photochemical regimes during high-O3 episodes were more inclined to be considered as the NOx-limited regime. Detailed mechanism modeling based on multiple scenarios further suggested that the synergic emission reduction strategy of NOx and VOC, while focusing on NOx emission alleviation, would be practical options for controlling local O3 pollutions. This method could also provide policy-related guidance for the precise O3 pollution prevention and control in other industrialized Chinese cities.

Optical trapping force on a stratified chiral particle by high-order Bessel beam.

We examined optical trapping force (TF) exerted on non-uniform chiral stratified spheres by a high-order Bessel beam (HOBB). Present theories were proven to be valid by comparison with the existing reference. Numerical simulations considering the effects of various parameters on TF are displayed in detail. The results show that different chirality distributions in stratified chiral sphere will affect significantly the trapping characteristics, and a stable three-dimensional capture can be realized only by selecting the appropriate parameters of incident beam and particles. The theoretical investigations may provide an analytical method to help understand the interaction of light with more complex stratified chiral cells and thus become an encouraging approach to better design an optical manipulation system.

Omega-3 polyunsaturated fatty acids inhibit cardiomyocyte apoptosis and attenuate sepsis-induced cardiomyopathy.

OBJECTIVES: Sepsis can cause myocardial injury, which is one of the leading causes of death in critically ill patients. Fish oil rich in omega-3 polyunsaturated fatty acids (PUFAs) in ultralong chains has immunomodulatory effects and can inhibit the production of various critically ill proinflammatory cytokines. Therefore, this study focused on whether ω-3 PUFAs have a protective effect on sepsis-induced cardiomyopathy (SIC). METHODS: Male 6-8 weeks old C57BL/6 mice were pretreated with 3% special fish oil supplement rat food for seven consecutive days prior to surgery. Cecal ligation and puncture (CLP) was perfromed to induce polymicrobial sepsis.The cardiac function was assessed by echocardiography, apoptosis of cardiomyocyte were detected by TUNEL assay and Western blotting, and the level of TNF-α, IL-6, and IL-1ß in plasma was determined 24h after CLP. RESULTS: Pretreatment with omega-3 PUFAs attenuated cardiomyocyte apoptosis, decreased the production of proinflammatory cytokines, attenuated the SIC, and improved the survival rate of septic mice induced by CLP. CONCLUSIONS: ω-3 PUFAs alleviate SIC through attenuating cardiomyocyte apoptosis, which provides a new direction for the prevention and treatment of SIC.

[Size Distribution and Source Appointment of Road Particles During Winter in Tianjin].

The significant role of traffic emissions mixed from various sources in urban air pollution has been widely recognized. However, the corresponding contributions to the roadside particle distribution are poorly understood due to the mixed impacts of various sources. Particle number concentrations of different sizes at the roadside in Nankai District of Tianjin were continuously monitored using a portable aerosol particle spectrometer during the morning rush hour (07:30-09:20) from Nov. 9, 2018 to Jan. 6, 2019. Characteristic and influencing factors of particle size distributions were discussed combined with temperature and relative humidity data, while potential sources of particles at the roadside were identified based on size distribution analysis. The results showed that the average total particle number concentrations were 502 cm-3, and the concentrations of the accumulation mode and coarse mode were 500 cm-3 and 2 cm-3, respectively. The distribution of number concentrations at the roadside was unimodal and primarily concentrated at 0.25-0.50 µm, with peak sizes at 0.28-0.30 µm. The same distribution trend of particle number concentration and difference in the concentration in the same segment size were observed at different periods. Vehicle activity level was the main influencing factor of road particulate matter concentration on different weekdays; the probability of the high value of road particulate matter concentration was reduced by a reasonable combination of the vehicle tail numbers. Temperature and relative humidity were both found to be positively correlated with the number concentration of particles. With the increase in temperature and relative humidity, the total and peak particle number concentration showed an overall upward trend. In addition, the peak particle size increased from 0.28-0.30 µm to 0.35-0.40 µm when relative humidity was higher than 80%. Three sources, including road dust, brake and tire wear, and the aging particles from vehicle exhaust, were identified using positive matrix factorization in this study. Road dust contributed 8.6% of the total number concentration, which mainly consisted of particles with sizes above 5.00 µm. Brake and tire wear contributed 2.8% of the total number concentration of particles with a size range of 0.80-4.00 µm. The aging particles from vehicle exhaust contributed the most (88.5%), with a peak at 0.25-0.65 µm. The sources of roadside particles were mainly related to vehicle activity, whereas temperature and relative humidity also affected the particle number size distribution.

Frequency and mortality of sepsis and septic shock in China: a systematic review and meta-analysis.

BACKGROUND: Sepsis, a life-threatening organ dysfunction induced by infection, is a major public health problem. This study aimed to evaluate the frequency and mortality of sepsis, severe sepsis, and septic shock in China. METHODS: We Searched MEDLINE, Embase, PubMed, and Cochrane Library from 1 January 1992 to 1 June 2020 for studies that reported on the frequency and mortality of sepsis, severe sepsis, and septic shock conducted in China. Random effects models were performed to estimate the pooled frequency and mortality of sepsis, severe sepsis, and septic shock. RESULTS: Our search yielded 846 results, of which 29 studies were included in this review. The pooled frequency of sepsis was estimated at 33.6% (95% CI 25.9% to 41.3%, I2 = 99.2%; p < 0.001), and the pooled mortality of sepsis, severe sepsis and septic shock were 29.0% (95% CI 25.3%-32.8%, I2 = 92.1%; p = 0), 31.1% (95% CI 25.3% to 36.9%, I2 = 85.8%; p < 0.001) and 37.3% (95% CI 28.6%-46.0%, I2 = 93.5%; p < 0.001). There was significant heterogeneity between studies. With a small number of included studies and the changing definition of sepsis, trends in sepsis frequency and mortality were not sufficient for analysis. Epidemiological data on sepsis in the emergency department (ED) are severely lacking, and more research is urgently needed in this area is urgently needed. CONCLUSIONS: Our findings indicated that the frequency and mortality of sepsis and septic shock in China were much higher than North America and Europe countries. Based on our results, an extremely high incidence and mortality of sepsis and septic shock in China's mainland requires more healthcare budget support. Epidemiological data on sepsis and septic shock in ED are severely lacking, and more research is urgently needed in this area. Trial registration This systematic review was conducted according to the statement of the preferred reporting items for systematic review (PROSPERO CRD42021243325) and the meta-analysis protocols (PRISMA-P).

Comparative Safety, Efficacy and Survival Outcome of Anti-PD-1 Immunotherapy in Colorectal Cancer Patients With vs Without Hepatitis B Virus Infection: A Multicenter Cohort Study.

INTRODUCTION: Antiprogrammed cell death protein-1 (PD-1) immunotherapy has substantially broadened in scope for the treatment of colorectal cancer (CRC). However, comparative safety, efficacy and survival outcome of anti-PD-1 therapy in CRC patients with and without hepatitis B virus (HBV) infection remain unclear. METHODS: This multicenter, retrospective cohort study included 180 advanced-stage CRC patients with available serological markers for HBV infection treated with anti-PD-1 therapy at the Sixth Affiliated Hospital, Sun Yat-sen University and Sun Yat-sen University Cancer Center between December 2016 and December 2019. A propensity score-matched analysis was performed to compare the safety, efficacy, and survival outcome between HBV and non-HBV groups. RESULTS: The incidences of deficient mismatch repair and metastatic disease were significantly different between HBV and non-HBV groups (both P < 0.05). After propensity score-matched analysis, any grade immune-related adverse events and grade ≥ 3 immune-related adverse events were 47% vs 38% (P = 0.25) and 5% vs 6% (P = 1.0) between HBV and non-HBV groups, respectively. The overall response rate was 39% with 17 complete responses and 13 partial responses for the HBV infection cohort and 39% with 11 complete responses and 19 partial responses for the non-HBV infection cohort (P = 1.0). Two-year progression-free survival rates were 38% vs 40% (P = 0.596) and 2-year overall survival rates were 55% vs 63% (P = 0.401) for HBV vs non-HBV infection cohorts. DISCUSSION: The incidences of toxicity, efficacy and survival outcome were similar between patients with HBV infection and non-HBV patients receiving anti-PD-1 therapy, which supports to include CRC patients with HBV in clinical trials of anti-PD-1 therapy.

Association of Peripheral Blood Biomarkers With Response to Anti-PD-1 Immunotherapy for Patients With Deficient Mismatch Repair Metastatic Colorectal Cancer: A Multicenter Cohort Study.

Purpose: Deficient mismatch repair (dMMR) is an established biomarker for the response to the programmed cell death (PD)-1 inhibitors in metastatic colorectal cancer (mCRC). Although patients with dMMR mCRC could achieve a high incidence of disease control and favorable progression-free survival (PFS), reported response rates to PD-1 inhibitors are variable from 28% to 52%. We aimed to explore the additional predictive biomarkers associated with response to anti-PD-1 immunotherapy in patients with dMMR mCRC. Methods: This multicenter cohort study enrolled patients with dMMR mCRC receiving anti-PD-1 immunotherapy at the Sixth Affiliated Hospital of Sun Yat-sen University and Sun Yat-sen University Cancer Center between December 2016 and December 2019. The total information of 20 peripheral blood biomarkers, including T cells (frequency of CD4+ T cell, frequency of CD8+ T cell, and ratio of CD4+/CD8+), carcinoembryonic antigen (CEA), inflammatory markers, and lipid metabolism markers, was collected. The association between response or survival and peripheral blood parameters was analyzed. Results: Among the tested parameters, the ratio of CD4+/CD8+ and frequency of CD4+ T cell were significantly associated with PFS (p = 0.023, p = 0.012) and overall survival (OS; p = 0.027, p = 0.019) in a univariate analysis. A lower level of CD4+/CD8+ ratio or frequency of CD4+ T cell showed a significant association with better overall response rates (ORRs; p = 0.03, p = 0.01). The ratio of CD4+/CD8+ and frequency of CD4+ T cell maintained significance in multivariate Cox model for PFS (HR = 9.23, p = 0.004; HR = 4.83, p = 0.02) and OS (HR = 15.22, p = 0.009; HR = 16.21, p = 0.025). Conclusion: This study indicated that the ratio of CD4+/CD8+ and the frequency of CD4+ T cell might be crucial independent biomarkers within dMMR mCRC to better identify patients for anti-PD-1 immunotherapy. If validated in prospective clinical trials, the ratio of CD4+/CD8+ and the frequency of CD4+ T cell might aid in guiding the treatment of PD-1 inhibitors among patients with dMMR mCRC.

Thyroid hormone disorders: a predictor of mortality in patients with septic shock defined by Sepsis-3?

Decreased serum thyroid hormone levels and their prediction of mortality in septic patients are still controversial, especially with the evolution of the definition of sepsis. This study aimed to assess the ability of thyroid hormone disorders to predict the early mortality of patients with septic shock defined by Sepsis-3. Sixty-three adult patients with septic shock admitted to a university hospital emergency intensive care unit (EICU) were studied. Serum free T3 (FT3), free T4 (FT4), thyroid stimulating hormone (TSH), C-reactive protein (CRP), procalcitonin (PCT), and lactate levels were determined and compared with survival status and organ dysfunction. Among the 63 patients studied, lower serum FT3 and FT4 levels were significantly associated with higher sequential organ failure assessment (SOFA) scores. Patients with septic shock with lower levels of FT3 (≤ 1.70 pmol/L) and FT4 (≤ 9.99 pmol/L) had significantly increased 28-day mortality. There was no significant difference in the serum TSH level between the survivor and nonsurvivor groups. The areas under the receiver operating characteristic curves for FT3 and FT4 levels were associated with 28-day mortality (0.92 and 0.89, respectively) and were higher than that for SOFA (0.82), CRP (0.65) and lactate (0.59). The decrease in serum levels of FT3 and FT4 in patients with septic shock is associated with the severity of organ dysfunction and 28-day mortality. Early detection of serum FT3 and FT4 levels could help clinicians to identify patients at high risk of clinical deterioration.

Propagation of annular cos-Gaussian beams through turbulence.

The propagation characteristics of annular cos-Gaussian beams and Bessel-Gaussian beams in turbulence have been widely investigated. However, the expression of the average intensity of Bessel-Gaussian beams involves a complex double integral, which requires large computational resources and does not easily ensure accuracy. Under this background, through the general cos-Gaussian beam rotation, a new annular cos-Gaussian beam is proposed which not only has some properties of the general cos-Gaussian beam, but also properties similar to those of the Bessel-Gaussian beam. Moreover, the annular cos-Gaussian beam is simpler in form than the general one and much more time-saving in calculation than the Bessel-Gaussian beams. Based on the extended Huygens-Fresnel principle, the average intensity on a receiver plane of the annular cos-Gaussian beams can be simplified to a summation of several polynomials and it is in good agreement with that of low-order Bessel Gaussian beams. The average radius and the power in the bucket are also derived. In summary, the annular cos-Gaussian beam has promising applications for its quick calculation and simple form among annular beams and hollow beams.

Analysis of lateral binding force exerted on a bi-sphere induced by an elliptic Gaussian beam.

Based on the generalized Lorentz-Mie theory (GLMT) and the localized approximation of the beam shape coefficients, we derived the expansions of incident elliptic Gaussian (EG) beams in terms of spherical vector wave functions (SVWFs). Utilizing multiple scattering (MS) equations and electromagnetic momentum (EM) theory, the lateral binding force (BF) exerted on a bi-sphere induced by an EG beam is calculated. Numerical effects of various parameters such as beam waist widths, beam polarization states, incident wavelengths, particle sizes, and material losses are analyzed and compared with the results of a circular Gaussian (CG) beam in detail. The observed dependence of the separation of optically bound particles on the incidence of an EG beam is in agreement with earlier theoretical predictions. Accurate investigation of BF induced by an EG beam could provide an effective test for further research on BF between more complex particles, which plays an important role in using optical manipulation on particle self-assembly.

Occurrence and impact of polychlorinated dibenzo-p-dioxins/dibenzofurans in the air and soil around a municipal solid waste incinerator.

To assess the influence of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) on the environment in the vicinity of municipal solid waste incinerators (MSWIs), we determined the levels of PCDD/Fs in air and soil samples collected around a MSWI, which is the largest in China. The International Toxicity Equivalency Quantity (I-TEQ) concentrations of PCDD/Fs in air samples were from 0.0300 to 1.03pgI-TEQ/m(3) (0.445-13.6pg/m(3)), with an average of 0.237pgI-TEQ/m(3), while in soil samples they ranged from 0.520 to 3.40pgI-TEQ/g (2.41-88.7pg/g) with an average of 1.49pgI-TEQ/g. The concentrations of PCDD/Fs in air and soil samples were comparable to other areas, and PeCDFs were the dominant contributors, which was different from stack gas homologue patterns. Multivariate statistical analysis showed that PCDD/Fs emission from the MSWI did not directly affect the profiles of PCDD/Fs in air and soils, so that vehicles and unidentified emission sources should be considered. The daily inhalation levels of PCDD/Fs for children (0.0110 to 0.392pgI-TEQ/(kg·day) and adults (0.00600 to 0.221pgI-TEQ/(kg·day) near the MSWI were lower than the tolerable daily intake of 1.00 to 4.00pg WHO-TEQ/(kg·day), but in winter the values were higher than in summer. These results can be used as basic data for assessing the risk of PCDD/Fs exposure in residents living around this MSWI, and more monitoring programs and studies should be carried out around MSWIs.

Light scattering of a Laguerre-Gaussian vortex beam by a chiral sphere.

Since the development of the generalized Lorenz-Mie theory, electromagnetic scattering by arbitrary beams has drawn growing interest. The Laguerre-Gaussian (LG) vortex beam is well known for its orbital angular momentum. With the aim of investigating the analytical solution to the scattering of a chiral sphere by a LG vortex beam, particular attention is paid to the expansion expression of the LG vortex beam. The expansion coefficients are derived based on the expansion of a Hermite Guassian beam as the LG vortex beam can be expressed as the superposition of Hermite Guassian modes. The numerical results of the incident beam expansion coefficients convergence and the scattered field comparison with the reference prove the validity of the theoretical analysis and computation codes. The results reveal that there exists an optimal sphere size for the maximum scattered field which is determined by the topological charge, beam waist radius, and beam center position. The investigation could provide a foundation for the optical manipulation of chiral particles by a LG vortex beam.

Apportionment of the sources of high fine particulate matter concentration events in a developing aerotropolis in Taoyuan, Taiwan.

To investigate the characteristics and contributions of the sources of fine particulate matter with a size of up to 2.5 µm (PM2.5) during the period when pollution events could easily occur in Taoyuan aerotropolis, Taiwan, this study conducted sampling at three-day intervals from September 2014 to January 2015. Based on the mass concentration of PM2.5, the sampling days were classified into high PM2.5 concentration event days (PM2.5>35 µg m(-3)) and non-event days (PM2.5<35 µg m(-3)). In addition, the chemical species, including water-soluble inorganic ions, carbonaceous components, and metal elements, were analyzed. The sources of pollution and their contributions were estimated using the positive matrix factorization (PMF) model. Furthermore, the effect of the weather type on the measurement results was also explored based on wind field conditions. The mass fractions of Cl(-) and NO3(-) increased when a high PM2.5 concentration event occurred, and they were also higher under local emitted conditions than under long range transported conditions, indicating that secondary nitrate aerosols were the major increasing local species that caused high PM2.5 concentration events. Seven sources of pollution could be distinguished using the PMF model on the basis of the characteristics of the species. Industrial emissions, coal combustion/urban waste incineration, and local emissions from diesel/gasoline vehicles were the main sources that contributed to pollution on high PM2.5 concentration event days. In order to reduction of high PM2.5 concentration events, the control of diesel and gasoline vehicle emission is important and should be given priority.

[Effects of education level of men who have sex with men on their high risk sexual behaviors and the infection of HIV and syphilis].

OBJECTIVE: To study the effects of educational background of men who have sex with men (MSM) on their high risk sexual behaviors and the HIV/STI infection rates. METHODS: During July to November of 2009 and March to October of 2010, snowball and convenience sampling methods were adopted to recruit MSM from MSM venues and via the internet in Changzhou city of Jiangsu province, and finally 659 MSM were conducted a questionnaire survey and serological testing. According to the educational background of MSM, they were divided into 3 groups, that is, junior high school group (206 cases), high school group (254 cases), and university group (199 cases). The questionnaire mainly includes information on social demography, sexual behaviors, condom use, etc. Blood samples were collected for HIV and syphilis spirochete detection, and urine samples were also collected in 291 MSM who were recruited during July to November of 2009 for neisseria gonorrhoeae and chlamydia trachomatis nucleic acid detection. χ(2) test and other statistical analysis methods were used to compare the characteristics of sexual behaviors and HIV/STI infections in 3 groups. RESULTS: Of the 659 valid questionnaires returned, junior high school group, high school group, and university group accounted for 31.3% (206 cases), 38.5% (254 cases) and 30.2% (199 cases). Places where MSM of different education levels most often to seek sexual partners, were significantly different. Junior high school group and high school group mostly went to bath house/sauna club (56.3%, 116 cases) and bar (34.8%, 88 cases) for partners, respectively, while the university group sought partners mainly through the internet (41.1%, 81 cases) (χ(2) = 99.35, P < 0.05). 53.4% (109/204) of the junior high school group had anal sex with men in the last 6 months, which was higher than that of high school group (67.7%, 172/254) (χ(2) = 9.74, P < 0.05) and university group (72.7%, 144/198) (χ(2) = 16.04, P < 0.05) . A total of 54.4% (111/204) of the junior high school group had sex with women in the last 6 months, which was higher than that of university group (38.6%, 76/197) (χ(2) = 10.10, P < 0.05) , but was not statistically significantly different from that of high school group (46.9%, 119/254) (χ(2) = 2.59, P = 0.11) . The rates of condom use with men at the last anal sex in junior high school group (73.4%, 80/109) , high school group (78.0%, 131/168) and university group (73.9%, 105/142) were similar. The rates of condom use with women in the last intercourse in junior high school group, high school group and university group were 51.8% (57/110), 54.6% (65/119) and 61.8% (47/76), respectively(χ(2) = 1.88, P = 0.39) . In junior high school group, high school group and university group, the infection rates of HIV were 9.2% (19/206), 10.6% (27/254) and 5.6% (11/197) (χ(2) = 3.68, P = 0.16), the positive rates of neisseria gonorrhoeae were 3.8% (3/79), 3.4% (4/117) and 0.0% (0/95) (χ(2) = 3.85, P = 0.14), the positive rates of chlamydia trachomatis were 5.1% (4/79), 9.4% (11/117) and 4.2% (4/95) (χ(2) = 2.70, P = 0.26). The infection rate of syphilis in junior high school group was 19.9% (41/206), which was higher than high school group (12.2%, 31/254) (χ(2) = 5.11, P < 0.05) and university group (10.2%, 20/197) (χ(2) = 7.45, P < 0.05 ). CONCLUSION: There was no obvious correlation between education level and high risk sexual behaviors;MSM with lower education level were at higher risk of infection of syphilis.

Geometric detection based on one-dimensional laser range profiles of dynamic conical target.

One-dimensional laser range profiles (LRPs) contain abundant information regarding the shape, size, and attitude of detected objects. For a dynamic conical target, the variation of its size and attitude could have a significant effect on the projections of LRP peaks. Ground coordinates, target coordinates, and incident field coordinates are established to compute the LRP of dynamic cones. In order to inverse the size, a genetic algorithm is adopted. The cone heights and half-cone angles of three different cones are inversed. Moreover, the results are used to inverse the attitude angles at any sampling time in order to verify accuracy of the theory. The inversion mentioned in this paper can be applied in any targets of arbitrary material, shape, and attitude with great efficiency.

Electromagnetic scattering by a uniaxial anisotropic sphere located in an off-axis Bessel beam.

Electromagnetic scattering of a zero-order Bessel beam by an anisotropic spherical particle in the off-axis configuration is investigated. Based on the spherical vector wave functions, the expansion expression of the zero-order Bessel beam is derived, and its convergence is numerically discussed in detail. Utilizing the tangential continuity of the electromagnetic fields, the expressions of scattering coefficients are given. The effects of the conical angle of the wave vector components of the zero-order Bessel beam, the ratio of the radius of the sphere to the central spot radius of the zero-order Bessel beam, the shift of the beam waist center position along both the x and y axes, the permittivity and permeability tensor elements, and the loss of the sphere on the radar cross section (RCS) are numerically analyzed. It is revealed that the maximum RCS appears in the conical direction or neighboring direction when the sphere is illuminated by a zero-order Bessel beam. Furthermore, the RCS will decrease and the symmetry is broken with the shift of the beam waist center.

Analysis of rainbow scattering by a chiral sphere.

Based on the scattering theory of a chiral sphere, rainbow phenomenon of a chiral sphere is numerically analyzed in this paper. For chiral spheres illuminated by a linearly polarized wave, there are three first-order rainbows, with whose rainbow angles varying with the chirality parameter. The spectrum of each rainbow structure is presented and the ripple frequencies are found associated with the size and refractive indices of the chiral sphere. Only two rainbow structures remain when the chiral sphere is illuminated by a circularly polarized plane wave. Finally, the rainbows of chiral spheres with slight chirality parameters are found appearing alternately in E-plane and H-plane with the variation of the chirality.

[Comparative analysis on both high risk behaviours, infection of HIV and syphilis between married and unmarried men who have sex with men].

OBJECTIVE: To understand the distribution of marriage status among men who have sex with men (MSM) in the city of Changzhou, and to explore the impact of marriage on AIDS related high risk behaviors and HIV infection in this population. METHODS: Target sampling (snowball sampling) was adopted to carry out a cross-sectional study, and structured questionnaire-based interviews were conducted to collect information on social demography, HIV related high risk behaviors. Blood and urine samples were collected to detect HIV, syphilis, gonorrhea and Chlamydia trachomatis infections. RESULTS: Of the 655 participants, 37.4% were married. Married MSM mostly sought their sexual partners at the public bathing house (61.6%), while unmarried MSM were mainly through bars (33.6%) or internet (31.1%). The proportion of having anal sex with men during the last 6 months was lower in the married group (50.8%) than in the unmarried group (73.3%), (P < 0.001) The percentage of having sex with women in the last 6 months was significantly higher in the married group (68.9%) than that in the unmarried group (33.2%) (P < 0.001), (OR = 4.454, 95%CI: 3.168 - 6.261). The rates of condom use in the last anal sex with men in married and unmarried groups were 71.0% and 77.6%, respectively (P = 0.152). The rate of condom use in the last intercourse with women was significantly lower in the married group (44.0%) than that in the unmarried group (70.4%) (P < 0.001), (OR = 0.331, 95%CI: 0.205 - 0.535). In the sex trade, most of the married MSM would "buy" sex (66.7%), while unmarried MSM would "sell" sex (63.2%) (P < 0.05), (OR = 3.429, 95%CI: 1.255 - 9.366). The percentage of having drugs in the previous year was higher in married group (3.3%) than that in the unmarried group (0.8%) (P < 0.05). In married and unmarried groups, the infection rates of HIV, syphilis, gonorrhea and Chlamydia trachomatis appeared to be (8.6%, 8.6%), (17.1%, 12.3%), (1.6%, 2.4%), and (3.3%, 9.0%), respectively (P > 0.05). CONCLUSION: Marriage seemed to have had limited effects on reducing the high risk behaviors of MSM. Different and multiform interventions should be developed according to the different characteristics of married or unmarried MSM population.