[Influencing factors of suicidal ideation among men who have sex with men].

Objective: To investigate the prevalence of suicidal ideation among MSM, and to explore the influence of perceived social support and depression on suicidal ideation and the possible pathway. Methods: MSM who are ≥18 years, HIV-negative, and ever had sex with men (oral sex/anal sex) in the last year participated in is study. Cross-sectional survey and convenient sampling method were used to recruit MSM through a male social interaction platform Blued 7.5 software from December 2020 to March 2021, with a questionnaire survey. Demographic questionnaire, Perceived Social Support Questionnaire and Center for Epidemiologic Studies Depression Scale were employed to collect data. Mplus 8.3 was used for data analysis. Results: Among 1 394 eligible MSM participants, 25.7% (358/1 394) had suicidal ideation. Perceived social support could have a direct effect on suicidal ideation (ß=-0.11, P=0.009), and an indirect effect on suicidal ideation through depression (ß=-0.18, P<0.001). Conclusions: Suicidal ideation was found to be lower in MSM with a higher level of perceived social support and a lower level of depression. Using social media to improve MSM's perceived social support and reduce depressive symptoms might be an effective means to prevent suicidal ideation.

[Application of limiting antigen avidity enzyme immunoassay for estimating HIV-1 incidence in men who have sex with men].

Objective: To estimate the incidence of HIV-1 infection in men who have sex with men (MSM) in key areas of China through HIV-1 limiting antigen avidity enzyme immunoassay (LAg-Avidity EIA), analyze the deviation from the actual results and identify influencing factors, and provided reference for improving the accuracy of estimation results. Methods: Based on the principle of the cohort randomized study design, 20 cities were selected in China based on population size and the number of HIV-positive MSM. The sample size was estimated to be 700 according to the HIV-1 infection rate in MSM. MSM mobile phone app. was used to establish a detection appointment and questionnaire system, and the baseline cross-sectional survey was conducted from April to November 2019. LAg-Avidity EIA was used to identify the recent infected samples. The incidence of HIV-1 infection was calculated and then adjusted based on the estimation formula designed by WHO. The influencing factors were identified by analyzing the sample collection and detection processes. Results: Among the 10 650 blood samples from the participants, 799 were HIV-positive in initial screening, in which 198 samples (24.78%) missed during confirmation test. Only 621 samples were received by the laboratory. After excluding misreported samples, 520 samples were qualified for testing. A total of 155 samples were eventually determined as recent infection through LAg-Avidity EIA; Based on the estimation formula , the incidence of HIV-1 infection in MSM in 20 cities was 4.06% (95%CI:3.27%-4.85%), it increased to 5.53% (95%CI: 4.45%-6.60%)after the adjusting for sample missing rate. When the sample missing rate and misreporting rate were both adjusted, the incidence of HIV-1 infection in the MSM increased to 5.66% (95%CI:4.67%-6.65%). The actual incidence of HIV-1 infection in MSM in the 20 cities might be between 4.06% and 5.66%. Conclusions: Sample missing and misreporting might cause the deviation of the estimation of HIV-1 infection incidence. It is important to ensure the sample source and the quality of sample collection and detection to reduce the deviation in the estimation of HIV-1 infection incidence.

[HIV infection and related factors among men who have sex with men aged 50 and above].

Objectives: To explore the HIV prevalence and related factors among MSM aged 50 and above and provide evidence on the prevention and control of HIV/AIDS. Methods: Based on an MSM social application software Blued 7.1.6, we recruited participants through online convenience sampling to collect demographic variables, behavioral and self-reported HIV infection status, etc. Univariate χ2 test and multivariate logistic regression were used to analyze the related factors of self-reported HIV infection. Results: Self-reported HIV infection rate was 17.6%(126/714) among the participants. In multivariable analysis, participants who got divorced or widowed had a 2.07(95%CI: 1.34-3.21) times greater risk of self-reported HIV-positive than those who were married. Participants unaware of HIV-related knowledge showed a 1.92(95%CI:1.21-3.04) times greater risk of self-reported HIV-positive than those with better HIV-related knowledge. Participants who have ever been diagnosed with sexually transmitted disease (STD) showed a 3.17(95%CI:2.09-4.83) times greater risk of self-reported HIV-positive than those without STD infection history. Conclusion: Our findings indicated that the self-reported HIV infection rate was high among MSM aged 50 and above. Being divorced or widowed, being unaware of HIV-related knowledge and STD infection history was proved related with self-reported HIV infection.

[Study on cognition, willingness to test and influencing factors of hepatitis C based on social software for men who have sex with men].

Objective: To understand the cognition, willingness to test and influencing factors of hepatitis C (HCV) based on social software for men who have sex with men (MSM). Methods: An online questionnaire was used to investigate the target population of Blued platform users, including general demographic characteristics, sexual behavior, drug abuse behavior, cognition of hepatitis C prevention and treatment, past hepatitis C testing status and future testing willingness. There were 14 questions in the cognition part, and answering 10 or more questions were defined as "knowing" . Cognition rate, willingness to test and related influencing factors of hepatitis C were analyzed in different characteristics population. Data were analyzed by univariate and multivariate logistic regression. Results: A total of 1800 valid questionnaires were completed, of which 58.9% (1 061/1 800) had heard of hepatitis C, and the overall cognition rate of hepatitis C was 33.5% (603/1 800). The cognition rate of hepatitis C among those aged 30 years old, monthly income among RMB 5 000~10 000, high school education or above, and previous HIV testing [42.5% (371/873), 36.7% (191/520), 35.1% (584/1 663) and 37.4% (544/1453)] was considerably higher than those of the corresponding low-age, low-income, low-educated, not having HIV testing and not insisting on condom use, and the differences were statistically significant (P < 0.05). The proportion of respondents who were willing to undergo hepatitis C testing in the next 3 months was 82.5% (851/1 031). The proportion of respondents who were tested for HIV in the past, had anal sex in the past 6 months and had high-risk behaviors [85.2% (766/899), 86.1% (609/707) and 86.6% (610/704)] was considerably higher than those who had not been tested for HIV, had no anal sex and had no high-risk behaviors in the past 6 months, and the differences were statistically significant (P < 0.05). Conclusion: The survey respondents have a low cognition rate of hepatitis C, but have a higher willingness to test. Targeted publicity and education should be strengthened for this population, and convenient conditions should be provided to promote regular testing.

A comparison between electrospinning and rotary-jet spinning to produce PCL fibers with low bacteria colonization.

One of the important components in tissue engineering is material structure, providing a model for fixing and the development of cells and tissues, which allows for the transport of nutrients and regulatory molecules to and from cells. The community claims the need for new materials with better properties for use in the clinic. Poly (ε-caprolactone) (PCL) is a biodegradable polymer, semi crystalline, with superior mechanical properties and has attracted an increasing interest due to its usefulness in various biomedical applications. Herein, two different methods (electrospinning versus rotary jet spinning) with different concentrations of PCL produced ultra thin-fibers each with particular characteristics, verified and analyzed by morphology, wettability, thermal and cytotoxicity features and for bacteria colonization. Different PCL scaffold morphologies were found to be dependent on the fabrication method used. All PCL scaffolds showed greater mammalian cell interactions. Most impressively, rotary-jet spun fibers showed that a special rough surface decreased bacteria colonization, emphasizing that no nanoparticle or antibiotic was used; maybe this effect is related with physical (scaffold) and/or biological mechanisms. Thus, this study showed that rotary jet spun fibers possess a special topography compared to electrospun fibers to reduce bacteria colonization and present no cytotoxicity when in contact with mammalian cells.

[Risk of HIV infection and its factors among men who have sex with men: a geosocial networking application-based survey in Beijing of China, 2017].

Objective: To assess risk of HIV infection and its risk factors among men who have sex with men (MSM) in Beijing, China. Methods: We conducted a cross-sectional online survey in October, 2017. Inclusion criteria of participants were: aged 18 year or more; resided in Beijing; conducted homosexual activities in past six months; self-reported HIV status as negative or unclear. Demographic information, HIV test history, social media use, and high-risk sexual behaviors were collected by a self-reporting questionnaire, and a HIV risk assessment tool was used to assess HIV risk of MSM, 5 388 particpants were finally enrolled in the study. Logistic regression model was used to analyze factors associated with risk of HIV infection. Results: Of the total 5 388 participants, most were 18-29 years old (64.35%), and the proportion of medium and high HIV risk score was 40.36%. The odds of medium and high HIV risk score among MSM who logged onto the app 1-20 times per week and>20 times per week were higher comparing with those who logged onto the app<1 time per week (OR=1.22, 95%CI: 1.02-1.46; OR=1.69, 95%CI: 1.38-2.06, respectively); MSM who completed college or higher education had lower probability of medium and high HIV infection risk, comparing with those who only had high school education level (OR=1.25, 95%CI:1.09-1.43) or junior or below education level (OR: 1.27, 95%CI: 1.05-1.53); MSM who did not conduct HIV test in past year had lower risk of medium and high HIV infection risk comparing with MSM who conducted HIV test in past year (OR=0.87, 95%CI: 0.77-0.99), and those who reported their HIV infection status unclear had higher probability of medium and high HIV infection risk than MSM who reported their HIV infection status negative (OR: 1.63, 95%CI: 1.44-1.86). Conclusion: The proportion of MSM who were in medium and high HIV infection risk score was high in Beijing. Lower level of education, high frequency of social media use, conducted HIV test in past year, and unclear of their own HIV infection status were associated with medium and high level of HIV infection risk.

[Qualitative research on factors of HIV testing among men who have sex with men in China based on Blued].

Objective: To understand the cognition and attitudes of men who have sex with men (MSM) towards HIV testing and explore in-depth reasons preventing them from testing. Methods: The function of "opinion" in Blued, a gay geo-social networking application (GSN), was adopted to collect qualitative data of ideas and attitudes towards HIV testing of the users between December 2017 and January 2018. The data was analyzed based on grounded theory approach. Results: 28 269 Blued users participated in the activity and 1 977 posted comments. Four key themes were identified, i.e. no/low risk of contracting HIV, stigmatization of HIV testing, long-term relationship and conventional impediments of HIV testing. Conclusion: The cognition and attitudes of the target population derived from the analysis of "opinion" function in Blued, such as the stigmatization of the behavior of HIV testing influencing the attitude of HIV testing, could help researchers build a more accurate detection and promotion strategy instead of a very general intervention on the public.

Thermodynamic and microstructural study of Ti2AlNb oxides at 800 °C.

The high-temperature structural applications of Ti2AlNb-based alloys, such as in jet engines and gas turbines, inevitably require oxidation resistance. The objective of this study is to seek fundamental insight into the oxidation behavior of a Ti2AlNb-based alloy via detailed microstructural characterization of oxide scale and scale/substrate interface after oxidation at 800 °C using X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and transmission electron microscopy (TEM). The oxide scale exhibits a complex multi-layered structure consisting of (Al,Nb)-rich mixed oxide layer (I)/mixed oxide layer (II)/oxygen-rich layer (III)/substrate from the outside to inside, where the substrate is mainly composed of B2 and O-Ti2AlNb phases. High-resolution TEM examinations along with high-angle annular dark-field (HAADF) imaging reveal: (1) the co-existence of two types (α and δ) of Al2O3 oxides in the outer scale, (2) the presence of metastable oxide products of TiO and Nb2O5, (3) an amorphous region near the scale/substrate interface including the formation of AlNb2, and (4) O-Ti2AlNb phase oxidized to form Nb2O5, TiO2 and Al2O3.

Mesoscale Fracture Analysis of Multiphase Cementitious Composites Using Peridynamics.

Concrete is a complex heterogeneous material, and thus, it is important to develop numerical modeling methods to enhance the prediction accuracy of the fracture mechanism. In this study, a two-dimensional mesoscale model is developed using a non-ordinary state-based peridynamic (NOSBPD) method. Fracture in a concrete cube specimen subjected to pure tension is studied. The presence of heterogeneous materials consisting of coarse aggregates, interfacial transition zones, air voids and cementitious matrix is characterized as particle points in a two-dimensional mesoscale model. Coarse aggregates and voids are generated using uniform probability distributions, while a statistical study is provided to comprise the effect of random distributions of constituent materials. In obtaining the steady-state response, an incremental and iterativesolverisadopted for the dynamic relaxation method. Load-displacement curves and damage patterns are compared with available experimental and finite element analysis (FEA) results.Although the proposed model uses much simpler material damage models and discretization schemes, the load-displacementcurvesshownodifferencefromtheFEAresults. Furthermore,nomeshrefinement is necessary, as fracture is inherently characterized by bond breakages. Finally, a sensitivity study is conducted to understand the effect of aggregate volume fraction and porosity on the load capacity of the proposed mesoscale model.

[The situation and associated factors of facility-based HIV testing among men who sex with men in Beijing].

Objective: To understand the prevalence of facility-based HIV testing and its associated factors among men who have sex with men (MSM) in Beijing city. Methods: An application-based cross-sectional survey was employed to understand HIV site test situation and associated factors. The survey was carried out from May 14(th) to 21(st), 2016. Users of a smart phone application for gay dating were recruited and those eligible for this survey were investigated with an online self-administered questionnaire. Information of demographics, sexual behaviors, facility-based HIV testing history and recreational drug abuses were collected. The multivariate logistic regression was used to make comparison among different groups and assess associated factors. Results: A total of 7 494 participants were enrolled in the survey with mean age of (28.81 ± 7.38) years, 87.14% (6 530/7 494) sought sexual partners through internet. The proportion of facility-based HIV testing in 1 year was 42.55% (3 189/7 494), MSM who were 25-29 years had higher proportion of facility-based HIV testing in 1 year, the proportion was 45.56%(1 104/2 423). Among MSM who could insist in using condom during anal sex (50.46% (1 539/3 050)), the proportion of HIV site testing in 1 year was higher. The MSM who reported seeking healthcare for symptoms of a sexually transmitted infections (STIs) in the past year or ever using recreational drug had higher proportion of facility-based HIV testing, the proportions were 56.81% (409/720) and 52.00% (1 340/4 917), respectively. Compared with alone cohabitation, cohabitating was associated with decreased odds of HIV facility-based testing in past 1 year(odds ratio (OR)= 0.79, P<0.001). Compared with homosexual sexual orientation, bisexual sexual orientation was associated with decreased odds of facility-based HIV testing (OR=0.83, P=0.004). With the increasing of number of male anal sex partners, the odds of HIV facility-based testing was increasing (OR=1.31, P<0.001) But with the decreasing of the frequency of condom using with male anal sex partners, the odds of facility-based HIV testing was decreasing (OR=0.85, P=0.014). Using recreational drugs (OR=1.36, P<0.001) and seeking healthcare for symptoms of a STI in the past 1 year (OR=1.73, P<0.001) were associated with decreased odds of HIV site testing. Conclusion: MSM in Beijing had lower proportion of facility-based HIV testing in past 1 year. Multiple anal sex partners, using recreational drugs, seeking healthcare for symptoms of a STI in the past year, cohabitating, bisexual sexual orientation, and lower frequency of condom using with male anal sex partners were associated with the odds of HIV facility-based testing in past 1 year.

Expression of microRNA-122 and microRNA-22 in HBV-related liver cancer and the correlation with clinical features.

OBJECTIVE: MicroRNAs (miR) participate in cell proliferation, apoptosis and transformation, as they can regulate gene expression and intracellular signal transduction for various physiological processes. MiR-122 and miR-22 are known to be related with occurrence and progression of hepatitis B virus (HBV)-related hepatocellular cancer (HCC). This study recruited HBV-related HCC patients, whose expression levels of miR-122 and miR-22 were determined to analyze the correlation with clinical and pathological indexes. PATIENTS AND METHODS: HBV-related HCC patients were enrolled, in parallel with patients suffering from benign liver disease and non-HBV-related HCC. Real-time PCR was employed to measure miR-122 and miR-22 expression levels. RESULTS: The relative expression levels of miR-122 and miR-22 in HBV-related HCC patients were 1.26 ± 2.73 and 5.49 ± 3.91, respectively, which were significantly lower than that in benign liver disease or non-HBV-related HCC patients (p < 0.05). No significant difference of serum miR-122 or miR-22 levels was found between benign liver disease and non-HBV-related HCC patients (p > 0.05). The miR-122 and miR-22 levels were negatively correlated with tumor size, lymph node metastasis, TNM stage, pathological type, differentiation grade, liver cirrhosis, AFP and HBV DNA, all of which were independent risk factors (p < 0.05). CONCLUSIONS: MiR-122 and miR-22 were downregulated in HBV-related HCC patients, and were related with tumor size, lymph node metastasis, TNM stage, pathological type, differentiation grade, liver cirrhosis, AFP and HBV DNA.

Associations of serotonin receptor gene HTR3A, HTR3B, and HTR3A haplotypes with bipolar disorder in Chinese patients.

Single nucleotide polymorphisms (SNPs) in HTR3A and HTR3B have been reported to be associated with bipolar disorder in European and Japanese populations. We explored the roles of 21 tag SNPs in HTR3A and HTR3B in susceptibility to bipolar disorder in a Chinese cohort. Twenty-one Tag SNPs were genotyped in a study consisting of 130 patients with bipolar disorder, who visited Shandong Mental Health Center between June 2013 and May 2014, and 109 healthy individuals as controls. All of the tag SNPs were genotyped using Sequenom MassArray matrix-assisted laser desorption/ionization time of flight spectrometry. Plink 1.07, Haploview 4.2, and SPSS 20.0 were used for the analysis of the genotypes and the associations of the haplotypes with bipolar disorder. Association analyses of tag SNPs detected significant associations with the A allele in HTR3A rs1176719 (P = 0.030) and the C allele in HTR3A rs1176713 (P = 0.048). Haplotype-based association analyses indicated a statistically significant (P = 0.035) five-SNP haplotype (rs1062613:C, rs11604247:C, rs1176722:G, rs2276302:A, rs1176719:G) of linkage disequilibrium in block 3. Analysis of our small Chinese sample revealed a significant association of HTR3A with bipolar disorder, but yielded no evidence of an association between HTR3B and bipolar disorder. Furthermore, evidence for an association was found for a haplotype of HTR3A. Studies with larger Chinese samples are needed to verify our findings.

Tricyclic Neovibsanin Scaffold (TCNS) as an Effective Antidepressant Agent.

Neovibsanin type natural products were found to display neurite outgrowth activity in PC12 cells. This suggests that such type of compounds could be promising candidates for the development of novel therapeutic agents to treat neurological diseases. In the present study rats after chronic mild stress (CMS) were treated with tricyclic neovibsanin scaffold (TCNS) to study its effect on depression. The results revealed that 15 mg/kg doses of TCNS reduced the duration of immobility in CMS model of depression. It led to a significant increase in neurite outgrowths which increased the synaptic and structural plasticity of neurons. Treatment with TCNS decreased the levels of MAO-A and caspase-3 expression both of which were found to be higher in CMS. TCNS also led to an increase in expression of heat shock protein 70 (Hsp70) in the hippocampus. These findings suggest that TCNS possesses antidepressant activity in CMS model of depression. Therefore the relief in depression by TCNS may be due to suppression of MAO-A expression and the apoptosis cascade by increased expression of Hsp70.

[Studies of the determination of glycyrrhizin acid kali salt by HPLC and the pharmacokinetics].

To find a practive and quick method determining GK concentration in blood by HPLC and to study its pharmacokinetics. GK from Glycyrrhiza uralensis Fisch was extracted and purified. GK were administered to mice by i.v. and ig. The Concentration of GK in blood at expected time was determined by HPLC. The data was dealed with by 3 P 87 programe. The concentration-time curve of i.v. 0.1% GK 40 mg/kg is in accordance with tow-compartment model. t1/2 alpha = 5.128 min, t1/2 beta = 51.196 min, AUC = 7477.642 (micrograms/ml).min, Cl(s) = 0.0956 microgram/min(microgram/ml). The c-t curve of ig. 2.2% GK 500 mg/kg is in accordance with tow compartment model, t1/2 alpha = 15.97 min, t1/2 beta = 200.05 min, AUC = 2453.96(micrograms/ml).min, Cl(s) = 3.642 micrograms/min(micrograms/ml). HPLC is a quick and practive method to determin the concentration of GK in blood.

[Study of the inclusion compound of rutin with beta-cyclodextrin].

In order to improve the solubility of Rutin in aqueous solution and the stability, the inclusion compound of Rutin with beta-CD was manufacted by saturated aqueous solution method. The formation of the inclusion compound was confirmed by IR spectroscopy and differential scauning calorimetry. The content of Rutin in inclusion compound was determined by UV. The results indicated that the inclusion compound of Rutin with beta-CD was formed. Quantitative analysis demmonstrated that the molecular ratio of Rutin to beta-CD in the complex was 1:1 with the inclusion constant of 283.79 L/mol at 30 degrees C. The dissolubility of Rutin in water has added to 643.19 mg/L (20 degrees C).

Growing radial basis neural networks: merging supervised and unsupervised learning with network growth techniques.

This paper proposes a framework for constructing and training radial basis function (RBF) neural networks. The proposed growing radial basis function (GRBF) network begins with a small number of prototypes, which determine the locations of radial basis functions. In the process of training, the GRBF network gross by splitting one of the prototypes at each growing cycle. Two splitting criteria are proposed to determine which prototype to split in each growing cycle. The proposed hybrid learning scheme provides a framework for incorporating existing algorithms in the training of GRBF networks. These include unsupervised algorithms for clustering and learning vector quantization, as well as learning algorithms for training single-layer linear neural networks. A supervised learning scheme based on the minimization of the localized class-conditional variance is also proposed and tested. GRBF neural networks are evaluated and tested on a variety of data sets with very satisfactory results.

[Study on shelf-life prediction of drugs under indoor natural light irradiation].

The photodegradation of drugs under natural light and various lamp light irradiation was studied and the shelf-life of drugs under indoor natural light irradiation was predicted with hydroxyprogesterone caproate injection as an example. The equivalent influences of different light sources on the photostability of the above drug were obtained. Therefore, the natural light photostability and the shelf-life of drugs under indoor natural light irradiation can be studied with lamp light exposure experiment. The photodegradation of hydroxyprogesterone caproate injection obeys zero order kinetics: C = C0-kEt, and its shelf-life under indoor natural light irradiation is about 1.9 years.

Utilization of the protoplast fusion technique to explore directional altering lincomycin producing microorganism.

Interspecific protoplast fusion between Streptomyces lincolnensis var. lincolnensis (LM gamma, CTC gamma, producing lincomycin) protoplast and Streptomyces aureofaciens (LM gamma, CTC gamma, producing chlorotetracycline) protpolast which had been treated with UV radiation 40 min for inactivation was performed with PEG 6000, the fusants were obtained by directly selecting from the regeneration plates containing CTC 50 micrograms/ml, the fusion frequency was about 9.05 x 10(-5). From many fusants, only 4 stable recombinants were obtained. These species produced antibiotics which are different from lincomycin and chlorotetracycline. Preliminary identification of the antibiotic synthesized by one of the recombinants suggests that its basic structure might be similar to that of lincomycin. The fermentation product of recombinant No. 2 showed new chromatographic spot which is similar to that of clindamycin. Though the products remain to be identified further, this strategy seems to be worthy of exploring for screening new antibiotics.