Respiratory protective equipment (RPE) is an effective measure to protect the health of workers. The domestic and foreign facial classfication of fit testing of RPE is mainly categorized into Los Alamos National Laboratory (LANL) classification, National Institute for Occupational Safety and Health (NIOSH) classification, principal component analysis (PCA) classification, Chinese Han adult facial classification, and Chinese young male facial classification. The LANL classification has low applicability. The NIOSH classification included different ethnicity and region of the study subjects, which is more representative for the American population. The PCA facial classification is complex to use and has low matching with RPE sizes. The Chinese Han adult facial classification and Chinese young male facial classification included more facial data of Chinese Han population and young population. There are qualitative and quantitative fit testing. Qualitative methods include the isoamyl acetate method, saccharin solution aerosol method, aerosol bitter testing solution method, and irritant smoke method which are cost-effective and easy to use, but are highly subjective to the study subjects. Quantitative methods include the aerosol generated method, environmental aerosol condensation nucleus counting method, and the controlled negative pressure method, which accurately quantify the facial fit of RPE but require specific testing equipment and high costs. It is necessary to include occupational populations from multiple industries, combine facial fit testing and fit testing methods of RPE, and establish a follow-up database based on digital information platforms, to achieve dynamic monitoring of respiratory protection levels among different occupational populations in the future.

Noise is a common occupational hazard in workplaces. Long-term exposure to high-intensity noise mainly causes occupational noise-induced hearing loss (ONIHL). The development of ONIHL is irreversible, and there is currently no cure. At present, risk assessment methods based on noise exposure intensities mainly include risk index assessment method, Engineering Professional Council assessment method in United Kingdom (EDC assessment method in UK), National Institute of Occupational Safety and Health assessment method in United State (NIOSH assessment method in US), and International Standardization Organization assessment method (ISO assessment method). However, the risk index assessment method is subjective and does not consider the effectiveness of workers wearing protective equipment. The EDC assessment method in UK defines ONIHL differently from China. The NIOSH assessment method in US and ISO assessment methods have population data sources that deviate from China, which can lead to bias in risk assessment. In the future, it is necessary to further carry out application research on the risk assessment of ONIHL in Chinese noise-exposed workers, compare the applicabilities of various assessment methods, conduct large-sample population epidemiological studies for verification, and fully utilize the risk-prediction function to prevent and control ONIHL.

ObjectiveTo explore the protective effect of hearing protectors worn by noise-exposed workers and its influencing factors. Methods A total of 329 occupational noise-exposed workers were selected as the research subjects by judgment sampling method. A questionnaire survey on the use of ear protectors and individual suitability tests was conducted. Intervention was carried out for those whose personal attenuation rating (PAR) did not pass the baseline standard. Results The median (M) and the 25th and 75th percentiles of baseline PAR were 17.0 (5.0, 22.5) dB. The baseline PAR of the workers who were male, aged 25-<35 years, with a working experience of 5-<15 years, with a college degree or above, wearing ear protectors for 5-<15 years, knowing the right way to wear ear protectors, and workers who wore ear protectors correctly during work was relatively high (all P<0.01). The unqualified rate of baseline PAR of the study subjects was 32.8%. The unqualified rate of baseline PAR of workers in automobile manufacturing enterprises was lower than that of workers in plastic enterprises and textile enterprises (9.2% vs 43.6%, and 9.2% vs 50.0%, both P<0.01). The M of the 108 unqualified worker on baseline PAR was improved after intervention (22.0 vs 1.0 dB, P<0.01). The rates of knowing the right way to wear ear protectors, wearing ear protectors correctly during work, and receiving training on wearing ear protectors correctly for the research subjects were 88.1%, 84.8%, and 86.6%, respectively. Workers in automobile manufacturing enterprises and plastic enterprises had higher rates of knowing the right way to wear ear protectors, wearing ear protectors correctly during work, and receiving training on wearing ear protectors correctly than those in textile enterprises (all P<0.01). Conclusion Gender, age, working experience, education level, duration of wearing ear protectors, knowledge and use of ear protectors correctly are influencing factors of the protective effect of ear protectors for noise-exposed workers.

OBJECTIVETo investigate common chromosomal changes and the LOH frequency of microsatellite loci in primary gastric cancer samples in order to locate the deleted regions in which human gastric cancer related genes might exist.

METHODSComparative genomic hybridization (CGH) was used to define global chromosomal aberrations in 43 primary gastric tumors. Based on the results of CGH, analysis of loss of heterozygosity (LOH) was performed in chromosome 19 in which the loss was first discovered in the gastric cancers. The PCR-based approach was used to investigate 22 loci, which are spaced at 1.1 - 10.9 cM intervals throughout chromosome 19. The amplified PCR fragments were subjected to electrophoresis in PAGE gel and analyzed with Genescan trade mark and Genotyper trade mark.

RESULTSCGH analysis revealed gains in chromosome 3p (8/43), 8q (8/43), 20 [20 (9/43), 20p (7/43), 20q (4/43)], 12q (16/43), 13q (12/43) and losses in 19 [19 (15/43)], 7 [17 (8/43), 17p (10/43)], 16 (10/43) and 1p (11/43). Among the 43 evaluated samples, the most frequent LOH was detected at locus D19S571 (27.81%).

CONCLUSIONSThe tumorigenesis of gastric cancer includes several chromosomal changes. The aberration of chromosome 19 was the first common change founded in gastric cancer. The region near the D19S571 might harbor potential genes related to the tumorigenesis of gastric cancer.

Objective To investigate the expression of melanoma antigen- encoding gene (MAGE) A1 protein in esophageal squamous cell carcinoma, and explore its correlation with the clinicopathological factors and prognosis. Methods A retrospective analysis was performed on 197 patients with esophageal squamous cell carcinoma who accepted radical surgical treatment from January 2006 to December 2012. The expressions of MAGEA1 protein in these specimens of cancer tissue and cancer adjacent tissue were detected by immunohistochemistry with tissue microarray technology. Results MAGEA1 protein was expressed in cytoplasm and nucleus of tumor cells. The positive expression rate of MAGEA1 protein in cancer tissue was significantly higher than that in cancer adjacent tissue: 73.6％ (145/197) vs. 5.6％ (11/197), and there was statistical difference (P<0.01). The positive expression of MAGEA1 protein had no correlations with sex, age, history of smoking/drinking, family history of upper gastrointestinal cancer, depth of tumor invasion, lymph node metastasis, tumor differentiation, location and TNM stage (P>0.05). Kaplan-Meier survival analysis result showed that the 5-year survival rate in patients with MAGEA1 protein positive expression was significantly lower than that in patients with MAGEA1 protein negative expression (37.2％ vs. 53.8％), and there was statistical difference (P=0.018). Multivariate analysis result showed that MAGEA1 protein positive expression was an independent predictor of prognosis in esophageal squamous cell carcinoma patients (HR=1.91, 95％CI 1.22 to 2.98, P = 0.004). Conclusions The expression of MAGEA1 protein is abundant in esophageal squamous cell carcinoma, and is related to worse clinical outcome. MAGEA1 protein could be a candidate target for tumor immunotherapy.

Objective:To explore the causal relationship between gut microbiota and lung function (FEV1/FVC) using two-sample Mendelian randomization method; To explore its application in the TCM field.Methods:This was a Mendelian randomization study. The GWAS data of gut microbiota from the MiBioGen consortium study and the GWAS data of lung function (FEV1/FVC) published by IEU OpenGWAS in the public database were used, and instrumental variables were extracted according to prespecified thresholds. The inverse variance weighted method (IVW) was mainly used for analysis. The results were evaluated according to the effect indicator β value and 95% CI. When the IVW method was statistically significant, further sensitivity analysis was performed. Leave-one-out test, heterogeneity test, horizontal gene pleiotropy test and MR-Egger regression intercept analysis were used to verify the stability and reliability of the results. Results:A total of 10 causal relationships between gut microbiota and lung function (FEV1/FVC) were determined using the IVW method: family. BacteroidalesS24.7group ( β=-0.029, P=0.015), family. ClostridialesvadinBB60group ( β=-0.028, P=0.040), family. Streptococcaceae ( β=-0.056, P=0.042), genus. LachnospiraceaeFCS020group ( β=0.025, P=0.029), genus. Lactococcus ( β=-0.024, P=0.038), genus. Peptococcus ( β=0.025, P=0.049), genus. RuminococcaceaeUCG011 ( β=-0.030, P=0.038), genus. Ruminococcus2 ( β=0.028, P=0.033), genus. Terrisporobacter ( β=-0.030, P=0.018), phylum. Cyanobacteria ( β=0.027, P=0.039). Leave-one-out analysis showed that the results were stable, and the effects of heterogeneity and horizontal gene pleiotropy on causal effect estimation could be removed. Conclusion:The gut microbiota may play a role in the changes of lung function, which to a certain extent confirms the TCM theory of "exterior-interior relationship between the lung and large intestine", and can provide certain reference for the research direction of TCM.

ObjectiveTo analyze the results of fit testing and its influencing factors on half-mask respirator among workers exposed to organic solvents. Methods A total of 84 workers exposed to organic solvents were selected as the research subjects using a convenience sampling method. The qualitative fit test apparatus of respiratory protection was tested after the workers had put on the half-mask respirats, and 11 facial indicators of the subjects were measured. Results The overall pass rate of the respirator fit testing was 71.4% (60/84). The lowest pass rate was 63.1% (53/84), which occurred during bending movements of workers. The head width, minimum forehead width, face length, nose length, nose depth, head circumference and head length were higher in workers who passed respirator fit testing, compared with those in the failing group (all P<0.05). The result of binary logistic regression analysis showed that gender and face width were influencing factors of the respirator fit testing (both P<0.05). Female workers had a lower pass rate of the fit testing than male workers, and workers with larger face width had a lower pass rate in the fit testing. Conclusion Drastic movement may lead to a decrease in the seal of half-mask respirator of workers exposed to organic solvents. When providing half-mask respirator to workers exposed to organic solvents, employers need to pay attention to the fit of respirators of female works and those with larger face width to ensure the effectiveness of respiratory protection for workers.

Objective:To investigate the safety of minimally invasive liver resection for resectable hepatocellular carcinoma (HCC) complicated with portal hypertension.Methods:The propensity score matching and retrospective cohort study was conducted. The clinicopathological data of 807 patients with resectable HCC who underwent minimally invasive liver resection in 8 medical centers, including Sir Run Run Shaw Hospital, Affiliated with the Zhejiang University School of Medicine et al, from June 2011 to November 2022 were collected. There were 670 males and 137 females, aged 58(50,66)years. Of the 807 patients, 173 cases with portal hypertension were divided into the portal hypertension group, and 634 cases without portal hypertension were divided into the non-portal hypertension group. Observation indicators: (1) propensity score matching and comparison of general data of patients between the two groups after matching; (2) intraoperative and post-operative situations; (3) subgroup analysis. Propensity score matching was done by the 1:1 nearest neighbor matching method, with the caliper setting as 0.001. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was conducted using the rank sum test. Count data were described as absolute numbers, and comparison between groups was conducted using the chi-square test or Fisher exact probability. Comparison of ordinal data was constructed using the non-parameter rank sun test. Results:(1) Propensity score matching and comparison of general data of patients between the two groups after matching. Of the 807 patients, 268 cases were successfully matched, including 134 cases in the portal hypertension group and 134 cases in the non-portal hypertension group. The elimination of the tumor diameter and robot-assisted surgery confounding bias ensured comparability between the two groups after propensity score matching. (2) Intraoperative and postoperative situations. The occlusion time of porta hepatis, cases with intraoperative blood transfusion, cases with postoperative complication, cases with complication >Ⅱ grade of Clavien-Dindo classification, cases of Clavien-Dindo classification as Ⅰ grade, Ⅱ grade, Ⅲ grade, Ⅳ grade, cases with liver related complication were 27.0(15.0,43.0)minutes, 33, 55, 15, 13, 29, 14, 1, 37 in the portal hypertension group, versus 35.0(22.0,60.0)minutes, 17, 25, 5, 14, 9, 4, 1, 13 in the non-portal hypertension group, showing significant differences in the above indicators between the two groups ( Z=-2.15, χ2=6.30, 16.39, 4.38, 20.72, 14.16, P<0.05). (3) Subgroup analysis. Results of subgroups analysis showed that in cases with major live resection, the operation time, volume of intraoperative blood loss, duration of postoperative hospital stay were 243.5(174.6,296.3)minutes, 200.0(150.0,600.0)mL, 7.5(6.0,13.0)days in the portal hypertension group, versus 270.0(180.0,314.5)minutes, 200.0 (75.0,450.0)mL, 7.0(5.5,10.0)days in the non-portal hypertension group, showing no significant difference in the above indicators between the two groups ( Z=-0.54, -1.73, -0.92, P>0.05). In cases with non-major live resection, the operation time, volume of intraoperative blood loss, duration of postoperative hospital stay were 170.0(120.0,227.5)minutes, 100.0(50.0,200.0)mL, 8.0(5.0,10.0)days in the portal hypertension group, versus 170.0(120.0,227.5)minutes, 100.0(50.0,200.0)mL, 7.0(5.5,9.0)days in the non-portal hypertension group, showing no significant difference in the above indicators between the two groups ( Z=-1.39, -0.10, 1.05, P>0.05). In cases with anatomical liver resection, the operation time, volume of intraoperative blood loss, duration of postoperative hospital stay were 210.0(150.0,285.0)minutes, 150.0(50.0,200.0)mL, 8.0(6.0,9.3)days in the portal hypertension group, versus 225.5(146.3,306.8)minutes, 100.0(50.0,250.0)mL, 7.0(6.0,9.0)days in the non-portal hypertension group, showing no significant difference in the above indica-tors between the two groups ( Z=-0.75, -0.26, -0.91, P>0.05). In cases with non-anatomical liver resection, the operation time, volume of intraoperative blood loss, duration of postoperative hospital stay were 173.5(120.0,231.5)minutes, 175.0(50.0,300.0)mL, 7.0(5.0,11.0)days in the portal hyper-tension group, versus 186.0(123.0,262.5)minutes, 100.0(50.0,200.0)mL, 7.0(5.0,9.5)days in the non-portal hypertension group, showing no significant difference in the above indicators between the two groups ( Z=-0.97, -1.12, -0.98, P>0.05). Conclusion:Minimally invasive liver resection or even major liver resection is safe and feasible for screened HCC patients complicated with portal hyper-tension, but attention should be paid to the prevention and treatment of postoperative complications.

Objective:To investigate the feasibility and safety of laparoscopic radical resection of hilar cholangiocarcinoma at multiple centers in China.Methods:Between December 2015 and August 2019, the clinical data of 143 patients who underwent LRHC in Affiliated Hospital of North Sichuan Medical College, Second Hospital of Hebei Medical University, Affiliated Hospital of Xuzhou Medical University, Affiliated Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Hunan Provincial People′s Hospital, the First Hospital Affiliated to Army Medical University, Sir Run Run Shaw Hospital Affiliated to Medical College of Zhejiang University, West China Hospital of Sichuan University, Nanfang Hospital of Southern Medical University and the First Affiliated Hospital of Chongqing Medical University were collected prospectively. There were 92 males and 51 females with age of (64±11) years (range: 53 to 72 years). Bismuth type: type I, 38 cases (26.6%), type Ⅱ, 19 cases (13.3%), type Ⅲa, 15 cases (10.5%), type Ⅲb, 28 cases (19.6%) and type Ⅳ, 43 cases (30.0%). The patients within the first 10 operation cases in each operation time (the first 10 patients in each operation team) were divided into group A (77 cases), and the patients after 10 cases in each operation time were classified as group B (66 cases); the cases with more than 10 cases in the center were further divided into group A 1 (116 cases), and the center with less than 10 cases was set as group A 2 (27 cases). T test or Wilcoxon test was used to compare the measurement data between groups, and the chi square test or Fisher exact probability method was used to compare the counting data between groups. Kaplan Meier curve was used for survival analysis. Results:All patients successfully completed laparoscopic procedure. The mean operation time was (421.3±153.4) minutes (range: 159 to 770 minutes), and the intraoperative blood loss was 100 to 1 500 ml (median was 300 ml) .Recent post-operative complications contained bile leakage, abdominal bleeding, abdominal infection, gastrointestinal bleeding, and delay gastric emptying, pulmonary infection, liver failure, et al.The post-operative hospital stay was (15.9±9.2) days. The operation time in group B was relatively reduced ( (429.5±190.7)minutes vs. (492.3±173.1)minutes, t=2.063, P=0.041) and the blood loss (465 ml vs. 200 ml) was also reduced ( Z=2.021, P=0.043) than that in group B. The incidence of postoperative biliary fistula and lung infection in patients in group A was significantly higher than that in group B (χ 2=4.341, 0.007; P=0.037, 0.047) .Compared with group A 2, the operation time in group A 1 was relatively reduced( (416.3±176.5)minutes vs. (498.1±190.4)minutes, t=2.136, P=0.034) , the incidence of bile leakage and abdominal cavity infection in group A 1 was lower than that in group A 2 (χ 2=7.537, 3.162; P=0.006, 0.046) . Kaplan Meier survival curve showed that the difference of short-term survival time between group A and group B was statistically significant ( P<0.05) . Conclusions:The completion of laparoscopic hilar cholangiocarcinoma radical surgery is based on improved surgical skills, and proficiency in standardized operation procedures.It is feasible for laparoscopic radical resection of hilar cholangiocarcinoma to well experienced surgeon with cases be strictly screened, but it is not recommended for widespread promotion at this exploratory stage.

Objective:To investigate the feasibility and safety of laparoscopic radical resection of hilar cholangiocarcinoma at multiple centers in China.Methods:Between December 2015 and August 2019, the clinical data of 143 patients who underwent LRHC in Affiliated Hospital of North Sichuan Medical College, Second Hospital of Hebei Medical University, Affiliated Hospital of Xuzhou Medical University, Affiliated Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Hunan Provincial People′s Hospital, the First Hospital Affiliated to Army Medical University, Sir Run Run Shaw Hospital Affiliated to Medical College of Zhejiang University, West China Hospital of Sichuan University, Nanfang Hospital of Southern Medical University and the First Affiliated Hospital of Chongqing Medical University were collected prospectively. There were 92 males and 51 females with age of (64±11) years (range: 53 to 72 years). Bismuth type: type I, 38 cases (26.6%), type Ⅱ, 19 cases (13.3%), type Ⅲa, 15 cases (10.5%), type Ⅲb, 28 cases (19.6%) and type Ⅳ, 43 cases (30.0%). The patients within the first 10 operation cases in each operation time (the first 10 patients in each operation team) were divided into group A (77 cases), and the patients after 10 cases in each operation time were classified as group B (66 cases); the cases with more than 10 cases in the center were further divided into group A 1 (116 cases), and the center with less than 10 cases was set as group A 2 (27 cases). T test or Wilcoxon test was used to compare the measurement data between groups, and the chi square test or Fisher exact probability method was used to compare the counting data between groups. Kaplan Meier curve was used for survival analysis. Results:All patients successfully completed laparoscopic procedure. The mean operation time was (421.3±153.4) minutes (range: 159 to 770 minutes), and the intraoperative blood loss was 100 to 1 500 ml (median was 300 ml) .Recent post-operative complications contained bile leakage, abdominal bleeding, abdominal infection, gastrointestinal bleeding, and delay gastric emptying, pulmonary infection, liver failure, et al.The post-operative hospital stay was (15.9±9.2) days. The operation time in group B was relatively reduced ( (429.5±190.7)minutes vs. (492.3±173.1)minutes, t=2.063, P=0.041) and the blood loss (465 ml vs. 200 ml) was also reduced ( Z=2.021, P=0.043) than that in group B. The incidence of postoperative biliary fistula and lung infection in patients in group A was significantly higher than that in group B (χ 2=4.341, 0.007; P=0.037, 0.047) .Compared with group A 2, the operation time in group A 1 was relatively reduced( (416.3±176.5)minutes vs. (498.1±190.4)minutes, t=2.136, P=0.034) , the incidence of bile leakage and abdominal cavity infection in group A 1 was lower than that in group A 2 (χ 2=7.537, 3.162; P=0.006, 0.046) . Kaplan Meier survival curve showed that the difference of short-term survival time between group A and group B was statistically significant ( P<0.05) . Conclusions:The completion of laparoscopic hilar cholangiocarcinoma radical surgery is based on improved surgical skills, and proficiency in standardized operation procedures.It is feasible for laparoscopic radical resection of hilar cholangiocarcinoma to well experienced surgeon with cases be strictly screened, but it is not recommended for widespread promotion at this exploratory stage.