Objective To simulate the microflow field environment between the anastomotic nail surface and intestinal wall tissue after implantation and to study the effect of hydrophobic surfaces on the flow rate of extracellular fluid and the fluid shear force on the wall to regulate bacterial adhesion through changes in the flow field.Methods The microstructure of shark skin was observed,and a simplified two-dimensional(2D)movement model of bacteria in a microflow field was established.Using computational fluid dynamics(CFD)numerical simulation,the movement of bacteria on a smooth surface and micro-textured surface in a static and dynamic flow field were simulated.The flow field characteristics around bacteria and the magnitude of fluid shear force under the two surface environments were compared,and the internal mechanism of the fluid shear force affecting bacterial adhesion was analyzed.Results The addition of the biomimetic microtexture enhanced the flow rate of the extracellular fluid in the microflow field,and the fluid had little viscous effect on the bacteria in the static flow field.The fluid in the dynamic flow field had a stronger pushing effect on the bacteria.The fluid shear force on the microtextured wall increased when the pit width was within a specific range.Conclusions The bionic micro-textured surface of the anastomotic nail can accelerate the flow rate of extracellular fluid,increase the fluid shear force of micro-textured walls and bacteria,and influence bacterial adhesion.These result provide a theoretical basis for studying bacteriostatic surfaces of anastomotic nails.

Objective:To explore the potential causal relationship between gut microbiota and teratozoospermia.Methods:We searched the database of Genome-Wide Association Study(GWAS)for gut microbiota-and teratozoospermia-related data.We used gut microbiota as an exposure factor,determined the instrumental variables according to the GWAS data on 18 340 participants released by the MiBioGen Alliance,and derived the outcome variables from the European data on teratozoospermia,with a sample size of 85 716,including 915 cases and 209 006 controls.Using inverse-variance weighting(IVW),MR-Egger regression and the weighted median estimator(WME),we performed two-sample Mendelian randomization(MR)analysis on the retrieved data,and estimated the causal relationship between gut microbiota and teratozoospermia based on the β value.Results:Two-sample MR analysis indicated that the class Erysipelotrichia,family Erysipelotrichaceae,family Streptococcaceae,genus Coprococcusl,genus Ruminococcaceae UCG009,genus Streptococcus,order Clostridialesm and order Erysipelotrichales were causally related with the increased risk,while the family Porphyromonadaceae with the decreased risk of teratozoospermia.Conclusion:The class Erysipelotrichia,family Erysipe-lotrichaceae,family Streptococcaceae,genus Coprococcusl,genus Ruminococcaceae UCG009,genus Streptococcus,order Clostridia-lesm and order Erysipelotrichales are one of the causes of teratozoospermia,related to the increased risk of the condition,while the family Porphyromonadaceae has a protective effect on sperm morphology,reducing the risk of teratozoospermia.

italic>Tussilago farfara L. is a perennial herb of Tussilago genus in the Compositae family. Its dried buds and leaves have good biological activities and have a long history of medicinal use in China and Europe. In this paper, we investigated the whole chloroplast genome characteristics, sequence duplication, structural variation and phylogeny of the Tussilago farfara L. After sequencing the Tussilago farfara L. chloroplast genome using Illumination technology, the complete Tussilago farfara L. chloroplast genome was further obtained by assembly and annotation, followed by a series of inverted repeat-large single copy/small single copy region contraction and expansion analysis, genome sequence variation, etc. The sequences of 13 homologous plants downloaded from NCBI were used to construct a neighbor-joining phylogenetic tree. The results showed that the total GC content of the chloroplast genome was 37.4% and the length was 150 300 bp; 125 genes were annotated, including 82 protein-coding genes, 35 tRNAs and 8 rRNAs; 148 (simple sequence repeats, SSR) loci were detected, and the relative synonymous codon usage showed that 31 codons out of 64 codons had a usage of >1. In the phylogenetic analysis, the chloroplast genomes of the seven species of Asteraceae, including the Yulin Tussilago farfara L., were highly conserved, and the sequence variation of the (large single-copy, LSC) and (small single-copy, SSC) regions was higher than that of the (inverted repeat, IR) region. This is in general agreement with the reported phylogeny of Yulin Tussilago farfara L. In this study, we obtained a high quality chloroplast genome and analyzed its genome characteristics, codon preference, SSR characteristics, SC/IR boundary, sequence variation and phylogeny, which can provide a basis for species identification, genetic diversity analysis and resource development of this medicinal plant.

Abstract: Objective - - To establish a pre column derivatization high performance liquid chromatography method for detecting Methods dimethyl sulfate (DMS) in workplace air. DMS in workplace air was collected with mercaptopyridine impregnated （ silicone tube. The derivative of DMS and mercaptopyridine was eluted by mobile phase phase A: water, phase B: acetonitrile, ∶ the volume ratio was 40 60) , and separated with a C18 column, then detected with diode array detector and quantitated by a Results - standard curve. The linear range of DMS was 0.17 40.00 mg/L, with the correlation coefficient of 0.999 95. The detection limit and the lower limit of quantitation were 0.05 and 0.17 mg/L respectively. The minimum detection concentration and minimum quantitation concentration were 0.02 and 0.04 mg/m³, respectively (air sample volume of 4.5 L, 1.0 mL sample - - - solution). The average desorption efficiency was 98.40% 102.00%. The within run and between run relative standard deviations - - were 0.61% 3.92% and 1.71% 6.00%, respectively. The samples could be stored at room temperature for at least 14 days. Conclusion This method can be used to detect DMS in workplace air.

Abstract: Nitrobenzene compounds (NBCs) are widely used in the world. It has 40 isomers such as nitrobenzene, dinitrobenzene and nitrotoluene, that are highly toxic and difficult to degrade and can cause harm to human health in different degrees. At pres⁃ ent, there is no unified standard method and occupational exposure limit for the detection of NBCs in the air. In terms of sampling medium, solid adsorption tube is mostly used for trapping vapor state NBCs, and filter membrane and solid adsorption tube are mostly used in series for sampling coexist NBCs in vapor state and aerosol state. In the detection methods, gas chromatography and liquid chromatography are common, and ultraviolet spectrophotometry, Raman spectroscopy, ion migration spectrometry and some other rapid response methods and technologies are also used in the detection of NBCs. In the detection of NBCs by gas chro⁃ matography, capillary column separation is commonly used, and the main detectors are flame ionization detector, electron capture detector and mass spectrometry detector. It is of practical significance to establish a method with high sensitivity, strong practica⁃ bility, convenient operation, and can simultaneously collect and detect a variety of NBCs in different states.

Objective - - To prepare the GDH 5 air sampling tube for simultaneous collection of eight kinds of chloro nitrobenzene （ ） ， compounds CNBs in the air of workplace and establish a matching determination method using gas chromatography. Methods - - ， Eight kinds of CNBs in vapor and aerosol state were collected by self developed GDH 5 air sampling tube desorbed ， ， ， by toluene separated by polysiloxane gas chromatography column detected by microcell electron capture detector and Results - （ - quantified by external standard method. It was determined that the air sampling tube was assembled by XAD 2 ion ） - ， exchange resin and glass fiber filter membrane. The linear range of CNBs was 0.80 240.00 mg/L and the linear correlation - - coefficients were greater than 0.999 9. The detection limit was 7.87 13.03 μg/L. The minimum detectable concentration was 0.60 3， - 3（ ） 1.33 μg/m and the minimum quantitative concentration was 2.00 4.22 μg/m sample 45.00 L . The average desorption - - （RSD） - ， - RSD efficiency was 101.2% 110.0%. The within run relative standard deviation was 0.8% 4.1% and the between run - Conclusion - was 0.3% 5.8%. The samples could be stored for more than 30 days at room temperature. GDH 5 air sampling tube and its associated determination method can be used for the collection and determination of eight kinds of CNBs in workplace air.

Objective: To investigate the influence of HBsAg expression in peritumoral tissue of hepatocellular carcinoma (HCC) patients on their postoperative recurrence. Methods: The HCC patients treated in Shanghai Eastern Hepatobiliary Surgery Hospital from October 2009 to August 2010 were selected. The clinicopathological data and adjacent tissues of 718 patients were collected, and dextran polymer immunohistochemical staining was used to detect the expression of HBsAg in adjacent tissues. According to the expression of HBsAg in adjacent tissues, the tissues were divided into HBsAg positive group and HBsAg negative group. Kaplan-Meier method and Log rank test were used for survival analysis, and Cox regression model was used for multivariate analysis. Results: Among the 718 patients in the whole group, 153 were HBsAg negative and 565 were HBsAg positive. There was a statistically significant difference in serum HBV DNA level between HBsAg-positive and HBsAg-negative patients (P<0.001). The number of patients with serum DNA≥2 000 IU/ml and<2 000 IU/ml in HBsAg negative group were 52 and 93, while the patients in HBsAg positive group were 325 and 205. The cumulative recurrence rates of all patients at 1, 3, and 5 years after surgery were 30.2%, 54.3%, and 62.7%, respectively. The expression of HBsAg was related to the recurrence (P=0.038). Multivariate analysis showed that γ-GT, PT, multiple tumors, tumor length, and portal vein invasion were independent risk factors for recurrence of HCC (P<0.05). In HBeAg-negative patients with low viral load (HBV DNA <2 000 IU/ml) and without cirrhosis, the recurrence rates of HBsAg-positive patients were 14.3% and 31.0% at 3 and 5 years, respectively, compared with HBsAg negative patients (all 0), the difference was statistically significant (P=0.021). Conclusion: The positive expression of HBsAg in peritumoral tissue increases the postoperative recurrence risk of HCC patients.
Carcinoma, Hepatocellular/pathology* ; China ; DNA, Viral/analysis* ; Hepatitis B Surface Antigens ; Hepatitis B virus/metabolism* ; Humans ; Liver Neoplasms/pathology*

Objective: As cytotoxic T cells, CD8+ T lymphocytes can kill tumor cells by releasing perforin and other effector molecules, but the correlation between their infiltration level and the prognosis of colorectal cancer varies in previous studies. This study aims to explore the distribution of CD8+T cells in tumor center and invasive margin of colorectal cancer, and to analyze their correlation with the prognosis of patients. Methods: A retrospective cohort study was used to analyze the clinicopathological features of 221 patients with colorectal cancer from the colorectal cancer pathological database of the Sixth Affiliated Hospital of Sun Yat-sen University between 2009 and 2012. Case inclusion criteria: (1) colorectal cancers confirmed by postoperative pathology; (2) patients with follow-up data. Exclusion criteria: (1) multiple primary cancers; (2) inflammatory bowel disease, Lynch syndrome or familial adenomatous polyposis; (3) no available paraffin slides; (4) patients receiving preoperative radiotherapy or chemotherapy. A total of 221 patients met the criteria. Immunohistochemical staining was used to count the CD8+ T cells in tumor center and invasive margin in the paraffin slides. Meanwhile the relative expression of CD8B gene in 22 fresh freeze samples of colorectal cancer was detected. Then the correlation of the expression with CD8+T cell density was examined. The patients were divided into high and low infiltration groups according to the level of CD8+T cells. Log-rank test was applied to compare the overall survival of the two groups of patients, and Cox regression analysis was used to adjust the prognostic significance of CD8+T cell infiltration. Results: There were 118 males and 103 females. In 221 slides, CD8+T cells infiltrating in invasive margin were more than those in tumor center [median (range): 37(0-141) / field vs. 14(0-106) / field, Z=-11.985, P<0.001], and the number of CD8+T cell in the tumor center was positively correlated with those in invasive margin (r=0.610, P<0.001). The number of CD8+ T cell in tumor center was positively correlated with the relative expression of CD8B gene (r=0.524, P=0.012). Survival analysis showed that the overall survival of the high infiltration group was better than that of the low infiltration group both in tumor center and invasive margin (median survival: 84.1 months vs. 73.5 months, P<0.001; 84.2 months vs. 75.9 months, P=0.002). Cox regression analysis revealed that high CD8+T cell infiltration in tumor center was an independent protective factor of overall survival (HR=0.369, 95% CI: 0.168-0.812, P=0.013). Conclusions: The infiltration level of CD8+T cells in tumor center is lower than that in invasive margin, and they are positively correlated. The level of CD8+ T cell infiltration in tumor center is related to overall survival and can be used as a potential pronostic marker.
CD8-Positive T-Lymphocytes ; Colorectal Neoplasms ; Humans ; Prognosis ; Retrospective Studies

Humans ; Perineum ; Rhabdomyosarcoma/diagnosis*

OBJECTIVE: To analyze the comparison results of volatile organic components in chemicals tested by occupational health laboratories.METHODS: A total of 37 reference laboratories that participated in the 2019 National Occupational Health Inspection and Testing Institution Laboratory Comparison Chemical Qualitative Testing Comparison organized by Guangdong Occupational Health Testing Center were selected as the research subjects. Headspace gas chromatography-mass spectrometry was used for the determination of volatile organic components in chemicals. The comparison results of reference laboratories were collected and implemented with qualitative and quantitative evaluation. RESULTS: The qualified rates of the qualitative results of the required hazard factors and other hazard factors in the reference laboratories were higher than those of the quantitative results of similar factors with statistical significance(83.78% vs 67.57%, 89.19% vs 56.76%, all P<0.05). There was no significant difference in the qualified rate of qualitative and quantitative results and comprehensive judgment results among each reference laboratory with other hazard factors(83.78% vs 89.19%, 67.57% vs 56.76%, 83.78% vs 89.19%, all P>0.05). The qualified rate of 37 reference laboratories was 89.19%(33/37). It showed no significant difference in the qualified rate of qualitative, quantitative and comprehensive judgment results among the reference laboratories of disease prevention and control system and non-disease prevention and control system(93.75% vs 85.72%, 85.00% vs 61.91%, 93.75% vs 85.52%,all P>0.05). CONCLUSION: There are great differences in the detection ability of volatile organic components on chemicals of each reference laboratory. The ability of qualitative detection is superior to the quantitative detection.