By using microwave extraction, a GC/MS method was developed for the determination of polycyclic aromatic hydrocarbons ( PAHs) content in soil which is around the discharge ditch of oily wastewater, and a correlation analysis of the content of organic matter in soil was carried out. The results showed that PAHs in the surface soil pollution were mainly from 2 to 4 rings of low molecular PAHs, and the PAHs with high molecular were not detected. Each sampling point belongs to slight or moderate pollution and the overall assessment is moderate pollution, which is middle and low lever in comparison with soil data of central regions. The origin may be the low molecular PAHs of oil pollution along with the atmospheric transmission, but it cannot be completely excluded the possibility of fuel combustion pollution. No obvious correlation was found between the content of polycyclic aromatic hydrocarbons and organic matter.

Objective: The prevalence of HIV/AIDS in people aged ≥50 years is increasing in China, resulting in another focus for AIDS prevention and control. A Meta-analysis was conducted to evaluate the HIV infection, its area and time distributions in people aged ≥50 years in China to provide evidence for the prevention and control of HIV/AIDS. Methods: Information on HIV infection rate in people aged ≥50 years in China were collected from Wanfang digital database, China National Knowledge Infrastructure (CNKI), PubMed and Embase. The R Studio1.1.456 software was used to calculate the pooled infection rate, and assessed the publication bias. Results: A total of 30 studies which covered 13 provinces were selected. From 2010 to 2018, the pooled HIV infection rate in people aged ≥50 years was 1.68% (95%CI:1.00%-2.79%). The HIV infection rate (2.60%) was higher in eastern China than in central and western China (0.16%, 2.13%). Conclusion The overall HIV infection rate in people aged ≥50 years is generally high in China. It is important to control the HIV infection in this population to facilitate the AIDS prevention and control in China.

Objective:To establish an in vivo model of acute radiation esophagitis in Wistar rats based on a small animal precision radiotherapy platform (SARRP). Methods:Thirty-six Wistar rats were randomly divided into control group, 40, 60 and 75 Gy groups. Based on MRI images, the esophageal target area of rats was outlined and the radiotherapy plan was formulated. The rats were respectively irradiated with 0, 8, 12 and 15 Gy per day for 5 consecutive days. The changes of body weight, food intake, esophageal pathology and magnetic resonance imaging were observed.Results:The body weight of rats in 75 Gy group decreased significantly on the 6th day after irradiation (IR) ( P<0.05). The esophageal tissue of rats in each IR group was thicker than that in control ( F = 14.20, P < 0.05). HE staining showed that the formation rate of radiation-induced esophagitis in 40 Gy and 60 Gy groups were 4/5 and 5/5, respectively, mainly mild. In 75 Gy group, the incidence of radiation-induced esophagitis approached to 5/5, of which 3/5 was severe at 9 d post-IR. The pathological injury scores [ M( Q1, Q3)] of rats in each group were 0, 1.0 (0.5, 2.5), 1.0 (1.0, 2.5) and 4.0 (1.5, 6.0) on the 9th day after IR. There was significant difference between the 75 Gy group and the control group ( H=12.69, P<0.05). After dynamic monitoring of neck MRI images, it was found that the esophageal signal of rats in each IR group increased and widened at 9 d post-irradiation. Conclusions:The animal model of acute radiation-induced esophagitis in rats was successfully established based on a small animal precision radiotherapy platform combined with MRI. 75 Gy was the best irradiation dose and the 9th day was the best observation time point.

Immunosuppressive tumor microenvironment is an important obstacle to tumor immunotherapy.Therefore,improving tumor microenvironment to enhance immune response is the key to improve the efficacy of immunotherapy.Based on the basic principle of immunology that the body has a strong response to"foreign"antigens and a weak response to preexisting antigens,pathogen infection can be combined with innate immune-related receptors to enhance the anti-tumor immune response.Pathogen vaccines can induce a"hot"tumor microenvironment with stronger antigen presentation and T lymphocyte activation,showing higher response to immunotherapy and having better security.In this review,we summarized the related studies on pathogen vaccine enhancing tumor immune response,including mixed bacterial vaccine,BCG vaccine,OK-432,synthetic vaccines based on tetanus toxin,modified vaccinia virus,influenza vaccine,Epstein-Barr virus and COVID-19 vaccine.The feasibility,application prospect and challenge of pathogen vaccine in tumor immunotherapy were discussed.

BACKGROUND:Subepithelial connective tissue grafts are generally considered as the gold standard for soft tissue augmentation.However,it needs a second surgical site,which will prolong the surgical time and increase patients'pain. OBJECTIVE:To compare the histological and thickness changes of attached gingiva following grafting with different soft tissue substitutes in the labial region of the cuspids. METHODS:In three Beagle dogs,attached gingival augmentation was performed with double-layer allogeneic acellular dermal matrix membrane(AADM),bovine-derived acellular dermal matrices(BADM)combined with concentrated growth factor membrane or BADM combined with collagen sponge.Thickness of attached gingiva was measured before augmentation,and 1,2,3,and 4 months after augmentation.Histological analyses were performed after 4 months. RESULTS AND CONCLUSION:The mean values of attached gingival thickness and attached gingival thickness augmentation were higher in the double-layer AADM group than in the other two groups(all P<0.05)from the 1st to 4th month after surgery.At 1 month after surgery,the attached gingival thickness of the three groups increased significantly and then decreased.At 3 months after surgery,the BADM combined with collagen sponge group and the BADM combined with concentrated growth factor membrane group showed no significant difference in the attached gingival thickness of the graft area compared with that before surgery(P>0.05).At 4 months after surgery,the mean value of attached gingival thickness in the double-layer AADM group was still significantly increased compared with that before surgery(P<0.05).The value of attached gingival thickness was highest in the double-layer AADM group,followed by the BADM combined with collagen sponge group,and the lowest in the BADM combined with concentrated growth factor membrane group at 1-4 months after surgery.Histological analyses revealed that AADM was well integrated with the host gingival tissue,and new fibrous connective tissue and fibroblasts grew into the AADM.But the grafts in the other two groups were absorbed and the augmentation area was remodeled into a structure consistent with the surrounding host tissue.To conclude,AADM is superior to BADM combined with concentrated growth factor and BADM combined with collagen sponge with regard to gingival augmentation.

Objective: To understand the AIDS awareness and related factors as well as the demands for AIDS-related health education programs, among first-grade students from three senior high schools in Tianjin. Methods: A cross-sectional study using both stratified cluster and convenient sampling methods was conducted. Anonymous questionnaires including social demographic characteristics, AIDS-related knowledge and needs for AIDS health education were distributed to the first-grade students from two general middle schools and one vocational senior middle school in Tianjin. Results: A total of 1 082 students were responding to the questionnaires. Among them, the overall awareness rates of AIDS-related knowledge were 34.3%(371/1 082), 71.9%(778/1 082) of the students had received knowledge about AIDS and 59.4% (643/1 082) of the students had received knowledge about sexual health in the past, from the three schools. There appeared statistical differences among the two types of schools. 7.0% (76/1 082) of the students reported having had sexual behaviors. Results from the multivariate logistic regression analysis showed that, in vocational senior middle school, the awareness rate of AIDS knowledge was lower (compared with general middle school, OR=0.41, 95%CI: 0.29-0.59) and in the following items, including no need in receiving safe sex health knowledge (compared with needs of safe sex health knowledge, OR=0.62, 95%CI: 0.43-0.91), no interests in reading AIDS-related health education materials (compared with attention to AIDS health education materials, OR=0.41, 95%CI: 0.30-0.56), not aware of safe sex behavior (compared with aware of safe sex behavior, OR=0.55, 95%CI: 0.39-0.77), not aware of correct condom use, compared with aware of correct condom use (OR=0.33, 95%CI: 0.24-0.46). Conclusions The overall awareness rate of AIDS knowledge was low among the first-grade students in Tianjin. Some students reported of already having had insertive sex, sexual health knowledge has a significant impact on AIDS knowledge, suggesting that sexual health education and AIDS health education among high school students be strengthened in Tianjin.