Prevalence of HIV infection and syphilis and related behaviors in clients in Ya'an of Sichuan province / 中华流行病学杂志

Objective: To understand the prevalence of HIV infection and syphilis in clients in Ya'an of Sichuan province. Methods: A survey was conducted in clients recruited through snowball method in Ya'an of Sichuan from April 2014 to December 2015. The information of the clients, including basic demography characteristics, AIDS knowledge awareness, high-risk behaviors and others, were collected through face-to-face interviews. Blood sample (5 ml) was taken from each client to test antibodies against HIV and syphilis. Statistical software SPSS 18.0 was used for data analysis. Results: Among the 708 clients, the constituent ratio of those aged ≥50 years was 51.27% (363/708), those in Han ethnic group was 99.72% (706/708), those with junior high school educational level or below was 90.11% (638/708), those who got married or cohabitated with others was 74.15% (525/708), and those who used condoms at each sex was 27.40% (194/708). Seven HIV positive cases were detected and 4 cases were aged ≥50 years. Seven syphilis cases were detected and all the cases were aged ≥50 year. No HIV-syphilis co-infection case was detected. The prevalence of HIV infection and syphilis were all 0.99% (95%CI: 0.30%-1.70%). Results from the multivariate logistic regression analysis showed that the clients who had their first commercial sex behavior at age <30 years (OR=6.61, 95%CI: 1.09-40.18) would have higher HIV positive rate. Conclusion: The rate of condom use was low in the clients in Ya'an and they didn't pay enough attention to their self-protection in sexual activities. Especially the clients aged ≥50 years were with low educational level and had high risk commercial sexual behaviors for HIV infection and syphilis. Close attention needs to be paid to them.

Fewer beams and segments result in a shorter delivery time and a better quality intensity-modulated radiotherapy plan in gastric cancer

Background: This study evaluated whether IMRT using fewer beams and segments could reduce delivery time without compromising plan quality in gastric cancer adjuvant radiotherapy

Materials and Methods: Fifteen patients with advanced gastric cancer who underwent D2, R0 surgery were included in this study. IMRT plans for each patient were designed as 7 equal beams with 40 segments, 5 beams with 25 segments and 4 beams with 20 segments. The dosimetric parameters were compared for the planned target volume [PTV]. The dose of normal organs at risk [OARs] was also assessed. The monitor units and treatment times of the different IMRT plans were calculated

Results: The 20-segment IMRT plan significantly reduced the PTV maximum dose compared to the 40-segment IMRT plan. The 20-segment IMRT plan improved left kidney and liver dose sparing in V20 and V30 as well as the 40-segment IMRT plan did and provided be4er protection for the V20 [13.86+/-7.78] of the right kidney, the V30 [9.25+/-4.04] of the le kidney, the D mean [19.68+/-2.47] of liver and D max [38.79+/-3.57] of the spinal cord. Irradiation times in the 20-segment and 25-segment plans decreased by 2.5 and 1.9 min, respectively, compared to the 40-segment IMRT plan

Conclusion: IMRT using fewer beams and segments reduced delivery time without compromising plan quality in gastric cancer adjuvant radiotherapy. Fewer segments IMRT plans lowered the monitor units and the treatment time