Factors associated with risk sexual behaviours of HIV/STDs infection among university students in Henan, China: a cross-sectional study.

BACKGROUND: This study aimed to identify factors associated with risk sexual behaviours and target high-risk groups at risk of HIV/STDs infection among university students. METHODS: The cross-sectional study was conducted from 1 November to 31 December 2020 in one university, located in Henan Province. A total of 1602 individuals who reported having ever had sex were analyzed as the subjects of this study. Descriptive analysis and multivariable logistic regression analysis were applied for this study to assess factors associated with risk sexual behaviours among university students. RESULTS: University students who reported having ever had sex accounted for about 9%, with an average age of 19.37 ± 1.03. Of them, having multiple sexual partners and inconsistent condom use during the last 6 months were 37.3% and 35%, respectively. Over 50% of participants had their sexual debut before the age of 18. Bisexual students (AOR = 0.27; 95% CI 0.16, 0.44) and those who lived on over 3000 Yuan per month (AOR = 0.50; 95% CI 0.28, 0.91) were consistently less likely to engage in condom use during the last 6 months. University students who were from high-grade (AOR = 1.56; 95% CI 1.12, 2.18 for sophomore; AOR = 1.84; 95% CI 1.28, 2.65 for junior; AOR = 2.07; 95% CI 1.38, 3.11 for senior), who lived on over 3,000 Yuan per month (AOR = 4.19; 95% CI 2.17, 8.11) or who reported being homosexual (AOR = 3.92; 95% CI 2.17, 7.06) and bisexual (AOR = 33.22; 95% CI 13.11, 84.15) were more likely to have multiple sexual relationships. University students who had sexual debut before the age of 18 were more likely to engage in risk sexual behaviours. CONCLUSIONS: The prevalence of sexual activity among Chinese university students is generally low, but risk sexual behaviours are of considerable concern. University students with higher living expenses, who are not heterosexual and who are younger at first sexual intercourse tend to engage in risk sexual behaviours. The scale-up of intervention is the need to prevent the expansion of the HIV epidemic among young students.

The HIV epidemic among university students is considerable, with the tendency of the high-risk population towards the general population. University students at risk of HIV/STDs infection tend to engage in risk sexual behaviours and were targeted for assessing factors corelated with their risk sexual behaviours in this study. Participants who reported having had sexual relations were selected. Information on the practice of risk sexual behaviours including multiple sexual partners and inconsistent condom use were collected and analyzed using a multivariable logistic regression model.Bisexual students were consistently less likely to use condoms within the last 6 months. University students from high-grade, who lived on over 3000 Yuan monthly, homosexual students and bisexual students were more likely to have multiple sexual relationships. University students who had sexual debut before the age of 18 were more likely to engage in risk sexual behaviours.In conclusion, University students with high cost of living per month, non-heterosexual, who are younger at first sexual intercourse tend to engage in risk sexual behaviours. Intensified intervention is the need to prevent the expansion of the HIV epidemic amongst young students.

HIV/AIDS-Related Knowledge and Attitudes Among Chinese College Students and Associated Factors: A Cross-Sectional Study.

In recent years, adolescent has become one of the high-risk groups for HIV. Meanwhile, good HIV awareness and positive attitude are essential for HIV prevention. This study aims to evaluate the extent to which college students understand HIV and their attitudes toward HIV-infected patients, as well as the correlative factors. The data used in this study came from a cross-sectional survey. An anonymous online questionnaire was used to investigate the demographic characteristics, HIV/AIDS-related knowledge, and attitudes toward HIV-infected patients of 17,678 students from a university in Henan. Descriptive statistics, Chi-square test and logistic regression were used to analyze differences and connections between variables in SPSS version 25.0. Participants' HIV/AIDS-related knowledge awareness rate was 80.8%. Levels of students' HIV/AIDS-related knowledge correlated with their gender, nationality, marital status, and their grade (p < 0.01). Female students [OR = 0.757, 95% CI (0.699-0.820)] and minority students (OR = 0.717, 95% CI (0.619-0.832)] had insufficient HIV health education knowledge. Meanwhile, male students (OR = 0.845, 95% CI (0.773-0.924)], and students with good HIV knowledge (OR unaware-ness/awareness = 2.385, 95% CI (2.111-2.694)] were more likely to hold a positive attitude toward HIV-infected patients. The relevant education departments should strengthen and promote the education of AIDS transmission and prevention. Many college students still hold negative attitude toward HIV-infected patients. The government should further make efforts to eliminate social discrimination in HIV-infected patients and lead people to approach HIV-infected patients fairly.

Gold-film coating assisted femtosecond laser fabrication of large-area, uniform periodic surface structures.

A simple, repeatable approach is proposed to fabricate large-area, uniform periodic surface structures by a femtosecond laser. 20 nm gold films are coated on semiconductor surfaces on which large-area, uniform structures are fabricated. In the case study of silicon, cross-links and broken structures of laser induced periodic surface structures (LIPSSs) are significantly reduced on Au-coated silicon. The good consistency between the scanning lines facilitates the formation of large-area, uniform LIPSSs. The diffusion of hot electrons in the Au films increases the interfacial carrier densities, which significantly enhances interfacial electron-phonon coupling. High and uniform electron density suppresses the influence of defects on the silicon and further makes the coupling field more uniform and thus reduces the impact of laser energy fluctuations, which homogenizes and stabilizes large-area LIPSSs.

Production rate enhancement of size-tunable silicon nanoparticles by temporally shaping femtosecond laser pulses in ethanol.

This paper proposes an efficient approach for production-rate enhancement and size reduction of silicon nanoparticles produced by femtosecond (fs) double-pulse ablation of silicon in ethanol. Compared with a single pulse, the production rate is ~2.6 times higher and the mean size of the NPs is reduced by ~1/5 with a delay of 2 ps. The abnormal enhancement in the production rate is obtained at pulse delays Δt > 200 fs. The production-rate enhancement is mainly attributed to high photon absorption efficiency. It is caused by an increase in localized transient electron density, which results from the first sub-pulse ionization of ethanol molecules before the second sub-pulse arrives. The phase-change mechanism at a critical point might reduce nanoparticle size.

Generation and elimination of polarization-dependent ablation of cubic crystals by femtosecond laser radiation.

We experimentally showed that the π/2-period oscillation of an ablation area with laser polarization direction can be observed in GaAs, ZnSe, MgO and LiF with cubic crystal by a femtosecond laser (800 nm, 100 fs) and that the modulation in the ablation area can be controlled by the laser fluence. While the polarization dependence is sustained in a wide range of laser fluences for a narrow band-gap crystal, it is strongly suppressed with a slight augmentation of laser fluence in a wide band-gap material. The polarization-dependent ablation is explained by the crystal's orientation-dependent reduced-electron mass and the resultant contrasting nonlinear absorptions with slightly different reduced electron mass. The interplay between photoionization and avalanche ionization is discussed to interpret the influence of laser fluence on polarization-dependent ablation. Based on Keldysh's theory, polarization-dependent ablation occurs in a mixed regime between tunneling and multiphoton ionization.