[Study on HIV testing behavior among men who have sex with men based on structural equation model].

Objective: To analyze HIV testing behaviors and associated factors in men who have sex with men (MSM) and provide evidence for making intervention on promoting HIV testing. Methods: Our observational study was conducted between April and June, 2018 in Wuxi, Jiangsu province in MSM. A self-completed questionnaire was used to collect the information about their socio-demographic characteristics, sexual behaviors, acceptance of intervention services, psychological status and HIV testing behaviors. Structural equation model (SEM) was chosen to fit data and the model was modified to analyze the relationships between variables. Results: A total of 410 MSM were enrolled in our study, among whom 72.9%(299/410) were aware of the necessity of HIV testing and 69.0%(283/410) reported having HIV tests in the last year. A modified structural equation model presented good fitting results with fitting index of root mean square error of approximation (RMSEA)was 0.065, normed fit index (NFI) was 0.946, relative fit index (RFI) was 0.922, Tucker-Lewis index (TLI) was 0.968 and comparative fit index (CFI) was 0.952. Results of SEM showed that intervention service was the factor with the largest standardized total effect value of 0.57 associated with HIV testing behaviors among MSM. Among intervention services, HIV testing reminding had the biggest factor loading of 0.88. Psychological status scores played a negative role in HIV testing behaviors among MSM with the path coefficient value of -0.33. Conclusions: The awareness and testing rate of HIV among MSM population need to be further improved. While effective measures are implemented to promote HIV testing among MSM, more attention should be paid to the mental health problems of MSM.

[Laboratory testing and tracing analysis of a typhoid epidemic in Jiangyin city, Jiangsu Province].

To conduct outbreak identification and transmission factor analysis of typhoid epidemic occurred in Xinqiao town, Jiangyin city from June to September 2016. A total of 14 strains of Salmonella typhi isolated from confirmed cases were collected, and 65 external environment samples and 13 food samples related to the outbreak were taken. Real-time PCR was used to detect specific gene of Salmonella typhi in the samples. Conventional method was used to isolate strains. The strains isolated from both the samples and patients in the epidemic were subjected to antimicrobial susceptibility testing and PFGE molecular characteristics. Salmonella typhi strain was isolated from one external sample (well water of a deli processing plant). The results of drug susceptibility showed that 15 strains were resistant to nalidixic acid. A total of 15 strains of Salmonella typhi were divided into 2 molecular patterns by pulsed field gel electrophoresis. The fingerprints of PFGE from the 13 patients and the environmental isolate were completely consistent, and there was one band difference from the other patient isolate. Combined with the epidemiological investigation and laboratory test results, it was determined that the outbreak was caused by genetic clone of the same Salmonella typhi. Food processing plant should be one of the key links.

Monitoring of lung malignant epithelial cells by gene methylation analysis in the conditionally reprogrammed cell cultures.

Conditionally reprogrammed cell (CRC) technology is an effective method for culturing primary malignant cells and non-malignant epithelial cells in vitro. This can be useful for precision medicine applications, such as drug sensitivity assays. However, this approach is commonly hindered by the non-specific growth of non-malignant epithelial cells in CRC cultures and the lack of effective biomarkers/assays to distinguish them from primary tumor cells. In this study, we developed a DNA methylation-based, real-time PCR assay to investigate SHOX2 and PTGER4 gene promoters as sensitive markers for human lung cancer. We first found that in formalin-fixed, paraffin-embedded (FFPE) malignant lung samples, 90% (28/31) had increased SHOX2 and/or PTGER4 promoter methylation as compared with their adjacent non-malignant samples. We then applied this assay to fresh surgical tumors and found increased SHOX2 and/or PTGER4 promoter methylation in 80% (20/25) of tumor samples as compared with their corresponding adjacent non-malignant tissues. Increased methylation of SHOX2 or PTGER4 promoter regions was also detected in 52% (13/25) of CRC cultures. The presence of malignant cells was confirmed by growth in soft agar cultures, a hallmark of malignant transformation, as well by EGFR mutation analysis. These results demonstrate that SHOX2 and PTGER4 promoter methylation levels can be used to detect malignant lung epithelial cells in CRC cultures.

[Analysis on voluntary blood donation and associated factors in men who have sex with men in 3 cities in China].

Objective: To assess the prevalence of blood donation and associated factors in men who have sex with men (MSM) in China. Methods: Our observational study was conducted between January and August, 2017 in 3 cities: Guangzhou, Shenzhen and Wuxi. Eligible participants were MSM (≥18 years old) who had either ≥2 male sex partners or unprotected anal sex with casual partners, or had been diagnosed with STI in the past 6 months. A self-completed tablet-based questionnaire was used to collect the information about MSM's socio-demographic characteristics, sexual behaviors and blood donation history. Results: A total of 603 MSM were enrolled in our study, including 302 in Guangzhou, 152 in Shenzhen and 149 in Wuxi, with a mean age of 27.9 years (SD=7.8). Overall, 29.2% (176/603) of the MSM reported a history of blood donation, and 33.1% (100/302)in Guangzhou, 27.6% (42/152) in Shenzhen and 22.8% (34/149) in Wuxi, the differences were not significant (χ(2)=6.421, P=0.093). Multivariate logistic regression analysis indicated that MSM had ever tested for HIV for ≥2 times in the past 12 months (vs. MSM tested for HIV one time, aOR=1.49, 95%CI: 1.08-2.19) or who had ever used gay dating app (vs. MSM who not used gay dating app, aOR=2.13, 95%CI: 1.12-4.44) were more likely to donate blood. Conclusions: Blood donation was common in MSM in China. Health education about blood donation in MSM should be strengthened to ensure the blood safety.

Expression of the 2-dehydro-3-deoxyphosphooc-tonate aldolase (KdsA) gene in mulberry leaves (Morus alba L.) is down-regulated under high salt and drought stress.

The oligosaccharide 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) is a key component of lipopolysaccharide in Gram-negative bacteria, and is also part of the pectic polysaccharide rhamnogalacturonan (RG-II) of the plant cell wall. The enzyme KDO-8-phosphate synthase (KDO8Ps), encoded by the 2-dehydro-3-deoxyphosphooctonate aldolase (KdsA) gene, catalyzes the first step in the synthesis of Kdo. In this study, the complete coding sequence of the KdsA gene from mulberry leaves was cloned and the primary structure of KDO8Ps was deduced. Alignment of the amino acid sequence of KDO8Ps from mulberry with those of five other plant species revealed a high level of evolutionary conservation. A phylogenetic tree analysis demonstrated a short genetic distance among KDO8Ps proteins of different species. Expression of the KdsA gene was higher in the second leaves than in the eighth leaves of mulberry, and was down-regulated under conditions of high salt or drought stress. Our results suggest that KdsA expression is important for the growth of new plant tissues, and is sensitive to harsh environments.

Mitogen-activated protein kinase signaling pathways are involved in regulating α7 nicotinic acetylcholine receptor-mediated amyloid-ß uptake in SH-SY5Y cells.

Intraneuronal accumulation of beta-amyloid protein (Aß) is an early pathological change in Alzheimer's disease (AD). Recent studies demonstrate that α7 nicotinic acetylcholine receptor (α7nAChR) binds to soluble Aß with a high affinity. In vitro and in vivo experiments also show that Aß activates p38 MAPK and ERK1/2 signaling pathways via the α7nAChR. Interestingly, it has been reported that p38 MAPK and ERK1/2 signaling pathways affect the regulation of receptor-mediated endocytosis. These data suggest that MAPK signaling pathways maybe involved in the regulation of α7nAChR-mediated Aß uptake. However, the evidence for this hypothesis is lacking. In the present study, we examined whether Aß1-42 oligomers activate MAPK signaling pathways via α7nAChR, and assessed the role of MAPK signaling pathways in the regulation of Aß1-42 uptake by α7nAChR. We confirm that undifferentiated SH-SY5Y cells are capable of taking up extracellular Aß1-42. The internalization of Aß1-42 accumulates in the endosomes/lysosomes and mitochondria. MAPK signaling pathways are activated by Aß1-42 via α7nAChR. Aß1-42 and α7nAChR are co-localized in SH-SY5Y cells and the expression of α7nAChR involves in Aß1-42 uptake and accumulation in SH-SY5Y cells. Our data demonstrate that Aß1-42 induces an α7nAChR-dependent pathway that relates to the activation of p38 MAPK and ERK1/2, resulting in internalization of Aß1-42. Our findings suggest that α7nAChR and MAPK signaling pathways play an important role in the uptake and accumulation of Aß1-42 in SH-SY5Y cells. Blockade of α7nAChR may have a beneficial effect by limiting intracellular accumulation of amyloid in AD brain and serves a potential therapeutic target for AD.

Genetic variation in the LMP/TAP gene and outcomes of hepatitis B virus infection in the Chinese population.

Genetic polymorphisms of the LMP/TAP gene coded by the HLA-II region may be associated with outcomes of HBV infection. We conducted a case-control study to test the hypothesis, including a persistent group of 155 patients with chronic hepatitis B and 36 healthy carriers, a recovered group of 165 individuals spontaneously recovered from HBV infection, and an uninfected group of 278 healthy normal controls. Genotypes of eight polymorphisms of the LMP/TAP gene were analysed by PCR-RFLP. A logistic regression model was used to analyse statistical differences in polymorphisms or haplotypes in different groups. Of the eight polymorphisms, two (TAP1 codon 637 and LMP7 codon 145) were observed to have statistically significant association with outcomes of HBV infection (P<0·05). The two-locus haplotype constructed with two such polymorphisms was analysed. The frequencies of haplotypes B (Asp-Lys), C (Gly-Gln), and D (Gly-Lys) were found to be increased significantly in the persistent group, compared to healthy controls (OR 2·26, 95% CI 1·62-3·15, P<0·001; OR 2·37, 95% CI 1·69-3·32, P<0·001; OR 4·38, 95% CI 1·78-10·77, P=0·001, respectively). The prevalence of haplotypes B (Asp-Lys), C (Gly-Gln), and D (Gly-Lys) were also significantly higher in the persistent infectious group than in the recovered group (OR 2·68, 95% CI 1·81-3·98, P<0·001; OR 2·40, 95% CI 1·62-3·55, P<0·001; OR 3·03, 95% CI 1·22-7·55, P=0·017, respectively). These findings indicated that genetic polymorphisms of the LMP/TAP gene might be an important factor in determining the outcome of HBV infection.

Identification of one intron loss and phylogenetic evolution of Dfak gene in the Drosophila melanogaster species group.

Intron loss and its evolutionary significance have been noted in Drosophila. The current study provides another example of intron loss within a single-copy Dfak gene in Drosophila. By using polymerase chain reaction (PCR), we amplified about 1.3 kb fragment spanning intron 5-10, located in the position of Tyr kinase (TyK) domain of Dfak gene from Drosophila melanogaster species group, and observed size difference among the amplified DNA fragments from different species. Further sequencing analysis revealed that D. melanogaster and D. simulans deleted an about 60 bp of DNA fragment relative to other 7 Drosophila species, such as D. elegans, D. ficusphila, D. biarmipes, D. takahashii, D. jambulina, D. prostipennis and D. pseudoobscura, and the deleted fragment located precisely in the position of one intron. The data suggested that intron loss might have occurred in the Dfak gene evolutionary process of D. melanogaster and D. simulans of Drosophila melanogaster species group. In addition, the constructed phylogenetic tree based on the Dfak TyK domains clearly revealed the evolutionary relationships between subgroups of Drosophila melanogaster species group, and the intron loss identified from D. melanogaster and D. simulans provides a unique diagnostic tool for taxonomic classification of the melanogaster subgroup from other group of genus Drosophila.

Effective volumetric lattice Boltzmann scheme.

An efficient fractional volumetric scheme is proposed for lattice Boltzmann method (LBM). By reducing the effective time step, the scheme possesses much better stability particularly for thermal LBM. The same accuracy and simplicity of the standard LBM are preserved for achieving the Navier-Stokes equation. Since the effective viscosity is reduced by the fraction factor p, the scheme becomes very effective for simulating high Reynolds number thermal flows.

"Coarse" stability and bifurcation analysis using time-steppers: a reaction-diffusion example.

Evolutionary, pattern forming partial differential equations (PDEs) are often derived as limiting descriptions of microscopic, kinetic theory-based models of molecular processes (e.g., reaction and diffusion). The PDE dynamic behavior can be probed through direct simulation (time integration) or, more systematically, through stability/bifurcation calculations; time-stepper-based approaches, like the Recursive Projection Method [Shroff, G. M. & Keller, H. B. (1993) SIAM J. Numer. Anal. 30, 1099-1120] provide an attractive framework for the latter. We demonstrate an adaptation of this approach that allows for a direct, effective ("coarse") bifurcation analysis of microscopic, kinetic-based models; this is illustrated through a comparative study of the FitzHugh-Nagumo PDE and of a corresponding Lattice-Boltzmann model.

Design of a scanning ellipsometer by synchronous rotation of the polarizer and analyzer.

We have designed and constructed a new type of spectroscopic ellipsometer to study the optical properties of materials in the 3500-8000-Å wavelength range. In the system, the analyzer and polarizer are driven 10(4) steps/revolution by two stepping motors that have hollow shafts and rotate synchronously with a speed ratio of 2:1, i.e., A = 2P. Both the polarizer and analyzer are mounted directly on the shafts to avoid mechanical transmission and vibration problems entirely and make the system simple and reliable. An additional source polarizer was placed in the optical path to reduce the slight polarization effects of the light source. The light intensity finally received by the detector contained five components, one dc and four ac, with frequencies of ω(0), 2ω(0), 3ω(0), and 4ω(0), respectively. One can independently obtain the ellipsometric parameters of ψ and Δ as well as the optical constants by calculating any one of the two sets of ac signals, with a raw data self-consistency of better than 0.5%. The incident angle, aligned precisely by a laser beam, was continuously variable through a mechanical system with a computercontrolled resolution of 0.001° or a visual resolution of 0.005°. The system operations, including data acquisition and reduction, high-voltage control of the photomultiplier, incident angle, as well as wavelength setting and scanning, were fully and automatically controlled by a 386-based microcomputer. We self-calibrated the system by adjusting and setting precisely the initial azimuthal angles of the prisms. The results from the measured spectra of the complex refractive index for a gold-film sample are presented, and we show that the data obtained at three different incident angles of 65°, 70°, and 75° are remarkably consistent with one another. A comparison of the two results from the ellipsometry and reflectance measurements is given. The experimental skills and system error reduction are discussed in detail.

[Long-term results of surgical treatment of patent ductus arteriosus in adults].

284 patients with patent ductus arteriosus were operated. Among them, 81 aged from 20-41. Special managements were made because of their serious pathologic changes. There was no operative mortality. 72 patients (88.9%) were followed up for 1-17 years. The results of follow-up indicated that the postoperative cardiopulmonary function improved greatly. 63 patients returned normal work. The long-term results were satisfactory.