[Global trends in the incidence and prevalence of pneumoconiosis in 204 countries/territories from 1990 to 2019].

Objective: To analyze the changing trend of incidence and prevalence of pneumoconiosis globally, and provide scientific basis for the formulation of health policy. Methods: In June 2022, through the Global Health Data exchange (GHDx) query tool (http: //ghdx.healthdata.org/gbd-results-tool) , the pneumoconiosis incidence and prevalence data was downloaded and organized. Estimated annual percentage change (EAPC) and age-standardized rate (ASR) were used to estimate the trends of pneumoconiosis from 1990 to 2019. EAPC was estimated by linear regression model based on ASR. Results: The overall ASR of the incidence and prevalence of pneumoconiosis decreased from 1990 to 2019, and their EAPCs were-0.85% (95%CI: -1.11%--0.60%) and -0.78% (95%CI: -1.08%--0.49%) . Over the past 30 years, the incidence and prevalence of pneumoconiosis in all SDI areas showed decreasing trends, especially in high SDI areas, their EAPCs were -1.46% (95%CI: -1.76%--1.15%) and -1.99% (95%CI: -2.44%--1.53%) . 110 countries/areas showed increasing trends in age standardized incidence rate (ASIR) , with Iran and Georgia showing the most pronounced upward trend, their EAPCs were 5.32% (95%CI: 4.43%-6.22%) and 4.39% (95%CI: 3.81%-4.97%) . 125 countries/areas showed anincreasing trends in prevalence ASR, with Iran had the fastest rise in prevalence (EAPC=6.40%, 95%CI: 5.33%-7.49%) . Conclusion: Although decreasing trends in the burden of pneumoconiosis are observed globally from 1990 to 2019, but the burden of pneumoconiosis in low-and middle-income countries or regions are still heavy. We need more effective strategies to prevent and reduce the burden of pneumoconiosis.

[Investigation of a carbon monoxide poisoning accident with a hidden source].

In June 2022, a carbon monoxide poisoning accident with hidden source occurred in a bonded gold/silver wire manufacturing enterprise in Guangzhou, causing 10 people to be poisoned, of which 1 was caused by carbon monoxide poisoning and 9 by carbon monoxide contact reaction. The symptoms were dizziness, fatigue and vomiting. After 5 to 7 h, the saturation of carboxyhemoglobin in finger pulse was 4% to 10%, and the saturation of carboxyhemoglobin in blood gas biochemical analysis was 1.9% to 5.8%. The concentration of carbon monoxide detected in the carbon borne purification plant of the enterprise was 34.46-37.26 mg/m(3). It was judged that the accident was carbon monoxide poisoning caused by carbon monoxide gas being transported to the work post along the gas transmission pipeline due to abnormal operation of the carbon borne purification plant. By investigating the source and cause of poison, this paper provides a warning for the similar process to prevent similar events, and provides a new idea for the identification of chemical poisoning risk. At the same time, it is warned that similar enterprises should fully consider the risk of poisoning under specific circumstances, strengthen equipment maintenance and repair, and prevent the occurrence of similar incidents.

[Value of the monocyte-to-lymphocyte ratio in the prognostic evaluation of hepatitis B-related acute-on-chronic liver failure].

Objective: To investigate the predictive value of the monocyte-to-lymphocyte ratio (MLR) for survival in patients with hepatitis B-related acute-on-chronic liver failure (HBV-ACLF). Methods: 92 cases with HBV-ACLF who were admitted to the General Hospital of Western Theater Command from October 2014 to October 2017 were selected. Clinical indicators were retrospectively collected, and their survival condition was followed up for 90 days, with the end point as death or liver transplantation. MLR levels predictive value among patients after 90 days of involvement was compared by analyzing the differences between the survival and death groups and its correlation with various indicators of liver function for prognosis. Results: 92 cases were included in this study, with a 90-day survival rate of 52% (48/92), and a mortality rate of 48% (44/92). MLR for survival and death groups were 0.520 (0.310, 0.828) and 0.740 (0.440, 1.120), respectively. MLR level was significantly higher in the death than survival group (P<0.05). Receiver operating characteristic curve (ROC) analysis showed that the area under the ROC curve (AUC) and 95% confidence interval for the survival group was 0.640 (0.527-0.754). The cutoff value for MLR was 0.399 at which the sensitivity and specificity were 0.864 and 0.396, respectively. Survival analysis showed that the 90-day survival rate was significantly lower in the high MLR group than corresponding low MLR group (P=0.011). Logistic multivariate regression analysis showed that after adjusting for other factors, MLR level was an independent prognostic factor in patients with HBV-ACLF. Conclusions: MLR can be used as a potential prognostic indicator for patients with HBV-ACLF, and its clinical value needs to be verified by large-scale prospective randomized trials.

Metabolomic profile of milk fermented with Streptococcus thermophilus cocultured with Bifidobacterium animalis ssp. lactis, Lactiplantibacillus plantarum, or both during storage.

In this study, the microbial interactions among cocultures of Streptococcus thermophilus (St) with potential probiotics of Bifidobacterium animalis ssp. lactis (Ba) and Lactiplantibacillus plantarum (Lp) in fermented milk were investigated during a storage period of 21 d at 4°C, in terms of acidifying activity (pH and titratable acidity), viable counts, and metabolites. A nontargeted metabolomics approach based on ultra-high-performance liquid chromatography coupled with mass spectrometry was employed for mapping the global metabolite profiles of fermented milk. Probiotic strains cocultured with St accelerated milk acidification, and improved the microbial viability compared with the single culture of St. The St-Ba/Lp treatment manifested a higher bacteria viability and acidification ability in comparison with the St-Ba or the St-Lp treatment. Relative quantitation of 179 significant metabolites was identified, including nucleosides, AA, short peptides, organic acids, lipid derivatives, carbohydrates, carbonyl compounds, and compounds related to energy metabolism. The principal component analysis indicated that St treatment and coculture treatments displayed a complete distinction in metabolite profiles, and Lp had a larger effect than Ba on metabolic profiles of fermented milk produced by cofermentation with St during storage. The heat map in combination with hierarchical cluster analysis showed that the abundance of metabolites significantly varied with the starter cultures over the storage, and high abundance of metabolites was observed in either St or coculture samples. The St-Ba/Lp treatment showed relatively high abundance for the vast majority of metabolites. These findings suggest that the profile of the metabolites characterizing fermented milk samples may depend on the starter cultures, and incorporation of probiotics may considerably influence the metabolomic activities of fermented milks.

[Clinical study of transjugular intrahepatic portosystemic shunt with Viatorr stent in 43 cases].

Objective: To investigate the clinical efficacy and safety of transjugular intrahepatic portosystemic shunt (TIPS) with the use of Viator stent in the treatment of cirrhotic portal hypertension. Methods: 43 cases with cirrhotic portal hypertension were implanted with Viatorr stent during TIPS procedure from March 2016 to August 2018. Serological indicators, color Doppler ultrasound, gastroscopy, rebleeding, ascites and hepatic encephalopathy were regularly followed up. Portal venous pressure, liver and kidney function, coagulation indexes were compared by t-test. Stent patency rate, hepatic encephalopathy incidence, rebleeding rate and survival rate were calculated by Kaplan-Meier curve. Results: TIPS procedure success rate was 100% in all patients. Portal pressure gradient was decreased from (25.57 ± 5.50) mmHg to (9.76 ± 2.92) mmHg before and after operation. Alanine aminotransferase (ALT) was significantly higher at 1 month after operation than before operation, but there was no significant difference between 3 and 6 months after and before operation. Total bilirubin, serum ammonia and prothrombin time at 1, 3, and 6 months after operation were higher than before operation. Albumin had no significant change compared with before operation, and creatinine and urea nitrogen were lower than before operation. The cumulative rebleeding rates at 12 and 24 months after operation was 0% and 9%, respectively. Of the 26 patients with ascites, 22 cases (84.6%) had complete disappearance of ascites and 3 (11.5%) had significant decrease of ascites. The cumulative incidence of hepatic encephalopathy at 3, 6, 12 and 24 months after surgery was 11.6%, 17.3%, 21.9% and 21.9%, respectively. The cumulative incidence of stent dysfunction at 12 and 24 months after surgery was 5.6% and 23.7%, respectively. The cumulative survival rate at 12 months and 24 months after surgery was 91.9%. Conclusion: TIPS procedure with Viatorr stent can effectively reduce portal pressure and rebleeding rate, improve intrahepatic shunt patency rate, and will not increase the risk of postoperative hepatic encephalopathy, and has a higher cumulative survival rate.

[Analysis of prognosis-related factors in patients with hepatitis B virus-related acute-on-chronic liver failure].

Objective: To investigate the prognosis-related factors and its predictive value in patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF). Methods: Sixty-three cases with HBV-ACLF were enrolled. According to the prognosis of 4-weeks, patients were divided into survival and death group. Univariate and multivariate analyses were performed on the clinical data of the two groups of patients to screen the risk factors affecting prognosis, evaluate its predictive value, and compare them with the MELD score, CTP score, and CLIFACLF score. The data were analyzed using t-test, Mann-Whitney U test, χ (2) test. Multiple logistic regression analysis was used for multiple risk factors. Results: There were 63 cases with HBV-ACLF, with 16 cases (25.40%) in the 4-week survival group, and 47 cases (74.60%) in the death group. The survival group age was 38.38 ± 14.50 years, which was significantly lower than the age of the death group 52.28 ± 12.51 years (P < 0.001). The survival group alpha-fetoprotein (AFP) level was 91.21 (8.38 ~ 154.10)µg/L, which was significantly higher than the level of the death group [12.60 (5.70 ~ 33.80) µg/L, P = 0.039]. The survival group alanine aminotransferase (ALT) level was 925.65 (523.43 ~ 1 364.80) U/L, which was much higher than that of the death group [371.60 (117.30 ~ 895.30) U/L, P = 0.040]. The survival group serum sodium level was (136.59 ± 4.03) mmol /L, which was significantly higher than the level of the death group [(132.22 ± 6.37) mmol/L, P = 0.013]. The survival group ascites severity level was much lower than that of the death group (P = 0.008). The survival group creatinine level was 56.50(49.43 ~ 86.25) µmol/L, which was much lower than the level of the death group [86.20 (68.00 ~ 143.00) µmol/L, P = 0.003]. Multivariate logistic regression analysis showed that ascites (OR = 0.470, 95% CI: 0.226 ~ 0.977) and age (OR = 0.941, 95% CI: 0.888 ~ 0.996) were risk factors affecting the HBV-ACLF prognosis. The area under the curve predicted liver failure prognostic score for ascites and age was 0.821, and the sensitivity and specificity were 68.8% and 87.2%, which was higher than the area under the curve predicted by the MELD score, CTP score, and CLIFACLF score, respectively. Conclusion: Age and ascites can be used to predict the clinical outcome in patients with HBV-ACLF. Younger patients without ascites have a higher survival rate at 4-weeks, but older patients with ascites are more likely to have a lower survival rate.

[An investigation and analysis of an acute occupational methyl acetate poisoning].

This article investigated an occupational chemical poisoning incident that occurred in a certain place in Guangdong Province in September 2020, detected the air at the scene, and analyzed the clinical data of the poisoned patients. The peripheral blood methanol concentrations of the three patients were 307.76 mg/L, 354.80 mg/L and 454.14 mg/L when they were admitted to the hospital. The raw and auxiliary materials were analyzed for volatile organic components. Methyl acetate was detected in the finished glue, synthetic resin and compound machine post glue in the glue room, and the relative percentages were 23.05%, 32.79% and 31.68%, respectively. Through comprehensive analysis, it was judged that this incident was an acute occupational methyl acetate poisoning incident, and 3 workers were poisoned.

In vitro antioxidant and angiotensin-converting enzyme inhibitory activity of fermented milk with different culture combinations.

This study investigated the effects of Lactobacillus plantarum (Lp) and Bifidobacterium animalis ssp. lactis (Ba) in co-cultures with Streptococcus thermophilus (St) on changes in the acidification profile, proteolytic activity, peptide production, in vitro antioxidant activity, and angiotensin-converting enzyme (ACE) inhibitory properties of fermented milks during 21 d of storage at 4°C. The pH values and proteolysis in all batches showed a gradual decrease and increase during storage, respectively. The ACE-inhibitory activity and total antioxidant capacity of all co-fermented milk samples followed a similar pattern, with maximum values on d 6 of storage. The St starter, in conjunction with Ba or Lp or both, enhanced proteolysis, peptide generation, and ACE-inhibitory and antioxidant activity, but decreased pH values compared with St alone. The St-Ba-Lp samples showed higher DPPH• (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, hydroxyl radical scavenging activity, and total antioxidant capacity, but similar superoxide anion scavenging activity compared to St-Ba or St-Lp samples. The St-Ba samples showed higher DPPH• radical scavenging activity but lower hydroxyl radical scavenging activity than St-Lp samples. In the ACE-inhibitory assays, the St-Lp samples exhibited relatively low activity among the co-fermented milks, digested or not. The presence of Ba and Lp in fermentation together did not affect ACE-inhibitory activity in undigested fermented milks compared with the presence of Ba alone, and St-Ba-Lp fermented milks demonstrated an increase in ACE-inhibitory activity after simulated gastrointestinal digestion in storage. Pepsin digestion largely improved ACE-inhibitory activity, except in St-Lp samples, in which the activity was reduced. Further hydrolysis by trypsin reduced final activity in digestion. This study suggests that co-cultured fermentation with probiotics improves in vitro antioxidant and ACE inhibition activity in fermented milks, and this effect is partly due to the higher proteolytic activity of probiotics.

[Breakthrough of invasive fungal disease with posaconazole as primary prophylaxis after induction chemotherapy for acute myeloid leukemia].

Objective: To investigate the breakthrough incidence of invasive fungal disease(IFD) and side effects of posaconazole as primary prophylaxis during induction chemotherapy for acute myeloid leukemia(AML). Methods: A total of 206 newly diagnosed AML patients admitted to our department during January 2016 and December 2018 were enrolled in the study. Exclusive criteria were as followings including patients diagnosed as acute promyelocytic leukemia; those who received intravenous antifungal therapy after admission or had history of IFD one month before induction chemotherapy, or those with functional insufficiency of vital organs and those older than 65. Forty-seven patients received posaconazole (posaconazole group), 61 cases received voriconazole (voriconazole group) and 98 cases did not receive any prophylaxis (control group) during induction chemotherapy. Prophylactic efficacy and safety between posaconazole and voriconazole were compared. Results: During induction chemotherapy, five possible cases of IFD occurred in posaconazole group (10.6%); while 11 cases (18.0%) were in voriconazole group including 7 possible, 3 probable and 1 proven. Thirty-five cases (35.7%) in control group were diagnosed as IFD including 19 possible, 11 probable and 5 proven ones. The incidences of IFD in posaconazole and voriconazole group were significantly lower than that in control group (P<0.05). The difference of posaconazole group and voriconazole group was not significant (P>0.05). The reported adverse events in posaconazole group were significantly lower than those in voriconazole group [12.8%(6/47) vs. 32.8%(20/61), P<0.05]. Conclusions: Posaconazole and voriconazole decrease IFD as primary prophylaxis during induction chemotherapy in patients with AML. The prophylactic effect of IFD with posaconazole is similar as voriconazole, but posaconazole shows better safety.

[Progress in the clinical diagnosis and treatment of hepatic vascular diseases].

The liver has a very special dual blood supply, including the portal vein (65%~75%) and hepatic artery (25%~35%). The hepatic veins returns blood to the systemic circulation via the portal vein, and hepatic artery after hepatic sinusoidal confluence. The lesions on the hepatic vein and its branches can cause ischemia and hypoxia or obstruction of the drainage system, portal hypertension, upper gastrointestinal variceal bleeding, hepatic encephalopathy, and so on. Clinically, hepatic vascular diseases are relatively rare, so the diagnosis and treatment are relatively difficult. Herein, we review the diseases related to the hepatic vascular system.

[Value of serum alpha-fetoprotein for the prognostic evaluation of hepatitis B virus-related acute-on-chronic liver failure treated with artificial liver].

Objective: To investigate the value of alpha-fetoprotein (AFP) level on survived hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) patients treated with artificial liver. Methods: Clinical indicators of HBV-ACLF patients who were previously treated with plasma exchange-based artificial liver at our department were retrospectively collected. The difference of serum AFP level between the survival and the death group was compared at 30, 90 and 180 days after artificial liver treatment. The ROC curves of the subjects were plotted, and the sensitivity and specificity of AFP for the survival prediction of the patients at 30, 90 and 180 days after artificial liver surgery were calculated. AFP was divided into a high AFP group and a low AFP group using median value. AFP and postoperative survival predictive value at 30, 90, and 180 days were analyzed. Results: A total of 93 cases were included in this study. The AFP of the survival group at 30, 90, and 180 days was (231.0 ± 286.2) ng / ml, (237.69 ± 297) ng / ml, (229.44 ± 286.46) ng/ml, and the death group was (76.4 ± 104.7) ng/ml, (103.13 ± 116.99) ng / ml, (136.34 ± 2.9.29) ng/ml, respectively. AFP of the death group was significantly lower than the corresponding survival group (P < 0.05). Receiver operating characteristic (ROC) curve analyses indicated that the area under the curve (AUC) and its 95% confidence interval at 30, 90, and 180 days after artificial liver surgery were 0.739 (0.611 ~ 0.867), 0.675 (0.550 ~ 0.80), 0.653 (0.524 ~ 0.781), respectively. The median serum AFP value was 110 ng/ml, and the survival analysis showed that the survival time of the high AFP group was significantly higher than the low AFP group at 30 d (P = 0.01), 90 d (P = 0.04) and 180 d (P = 0.03) after artificial liver surgery. Conclusion: Serum AFP can be used as a predictor of survival for HBV-ACLF patients after artificial liver therapy and its clinical value needs to be further verified by the larger sample size.

[Combined effect of noise and hand-transmitted vibration on noise-induced hearing loss in the automobile manufacturing industry].

Objective: To investigate the combined effect of noise and hand-transmitted vibration on noise-induced hearing loss (NIHL) in the automobile manufacturing industry. Methods: From September 2018 to January 2019, cluster sampling was used to select 998 workers in an automobile factory as study subjects, among whom 352 workers exposed to noise alone were enrolled as noise group, 342 workers exposed to noise and hand-transmitted vibration were enrolled as combined effect group, and 304 workers without exposure to occupational hazardous factors were enrolled as control group. A questionnaire survey and pure tone audiometry were performed for all study subjects. An analysis of variance was used for comparison of continuous data between groups, and the chi-square test was used for comparison of categorical data between groups; a ordinal polytomous logistic regression analysis was used to investigate the influencing factors for NIHL (with 0.05 as the inclusion criteria and 0.10 as the exclusion criteria for independent variables) . Results: There was a significant difference in L(Aeq, 8 h) between groups (P<0.05) ; the noise group and the combined effect group had a significantly higher L(Aeq, 8 h) than the control group (P<0.05) , while there was no significant difference in L(Aeq, 8 h) between the noise group and the combined effect group (P>0.05) . The control group had a significantly lower detection rate of hearing loss than the noise group and the combined effect group (P<0.0125) , and the combined effect group had a significantly higher detection rate of hearing loss than the noise group (P<0.0125) . The ordinal polytomous logistic regression analysis showed that after adjustment for confounding factors such as age, working years, sex, smoking, and drinking, both noise exposure and exposure to both noise and hand-transmitted vibration had an influence on workers' hearing (P<0.05) , and the workers exposed to both noise and hand-transmitted vibration had a higher risk of hearing loss than those exposed to noise alone. Conclusion: There may be a combined effect of noise and hand-transmitted vibration in the automobile manufacturing industry, which can increase the risk of NIHL in workers.

[Ikaros family zinc finger 1 mutation is a poor prognostic factor for adult Philadelphia chromosome positive acute lymphoblastic leukemia].

Objective: To analyze the prognostic impact of Ikaros family zinc finger 1(IKZF1) mutation on adult Philadelphia chromosome (Ph1) positive acute lymphoblastic leukemia (ALL) patients. Methods: IKZF1 mutation was detected in 63 adult Ph1 positive ALL patients at diagnosis using capillary electrophoresis. Recruited patients were treated in our center and other three hospitals in Ningbo from January 2014 to January 2017. Clinical data were collected and retrospectively analyzed. Results: Thirty-nine (61.9%) patients were positive IKZF1 mutation in this cohort. The white blood cell (WBC) count in IKZF1 mutation group was significantly higher than that of mutation negative group [(64.6±11.3)×10(9)/L vs. (33.7±5.6)×10(9)/L, P<0.05]. Patients with WBC count over 30×10(9)/L accounted for 56.4% in IKZF1 mutation group. Complete remission (CR) rate in the IKZF1 mutation group was also lower than that of negative group after induction chemotherapy (64.1% vs. 75.0%, P>0.05). IKZF1 was a negative prognostic factor but not independent factor for survival by univariate and multivariate analyses. Patients were divided into chemotherapy and allogeneic transplantation groups. The 3-year overall survival (OS) rate and 3-year leukemia-free survival (LFS) rate in IKZF1 mutation group were significantly lower than those of negative group in both transplantation group (42.3% vs. 59.3%; 31.2% vs. 50.0%; respectively, both P<0.05) and chemotherapy group (24.8% vs. 40.0%; 19.0% vs. 34.3%; respectively, both P<0.05). Conclusion: IKZF1 mutation is a poor prognostic factor for adult Ph1 positive ALL patients.

[An investigation of an accident of acute mixed gas poisoning].

An accident of mixed acute gas poisoning accident happened in a place in GuangDong in March 2018. To investigates three poisoning workers and related clinical data were summarized., we tested the field air and analyzed the accident reasons. This event due to the staff lack of occupational protection awareness and illegal operation. The working environment must be ventilated before limited space operation, and must be sure that the limited space is safe by toxic gas monitoring. In case of occupational acute gas poisoning, rescuers should help the persons who are poisoned reasonably and meanwhile their own safety.

[Application of semi-quantitative risk assessment method in occupational health risk assessment of wooden furniture manufacturing enterprises].

Objective: To explore the applicability of semi-quantitative risk assessment methods in wood furniture manufacturing companies. Methods: Two medium-sized wooden furniture manufactures were randomly selected as research objects, namely A company and B company. Used the Semi-Quantitative risk assessment method (the ratio method, the index method and the comprehensive method) in the "Guidelines for occupational health risk assessment of chemicals in the workplace" (GBZ/T 298-2017) to conduct occupational hygiene survey, occupational hazard factor testing and occupational health risk assessments for two wood furniture manufacturers from January to October 2018, and compared and analyzed the applicability of these three semi-quantitative risk assessment methods in wooden furniture manufacturing enterprises. Results: The occupational health status of A enterprises was worse than that of B enterprises, and the occupational health risk level was higher than that of B enterprises, and the risk level of A enterprise is 3~4, and the risk level of B enterprise is 2~3. The occupational health risk level obtained by the index method was consistent with the comprehensive method, while the risk level of some occupational disease hazards used the ratio method was inconsistent with the results of the index method and the comprehensive method. Compared with the index method and the comprehensive method, when E/OEL<0.5 or E/OEL≥2, there might be a certain fluctuation in the occupational health risk level obtained by the ratio method. Conclusion: The semi-quantitative risk assessment is more objective, comprehensive and flexible in the application of occupational health risk assessment, and can assess the occupational health risk level of chemical poisons in wood furniture manufacturing enterprises.

[Application of two risk assessment methods in ceramic manufacturing enterprises].

Objective: To explore the applicability of Singapore semi-quantitative assessment method and international committee on mining and metals occupational health risk assessment method in occupational health risk assessment of ceramic enterprises. Methods: From March 2017 to May 2018, A ceramic enterprise was selected for the investigation and testing of occupational health, and the risk assessment of the occupational-disease-inductive factors in the workplace was conducted by the semi-quantitative assessment method of Singapore and the occupational health risk assessment method of the international committee on mining and metals. Results: The occupational-disease-inductive factors in the production process of this ceramic enterprise mainly include silicon dust, noise, high temperature, carbon monoxide, carbon dioxide and so on. The two risk assessment methods were applied to assess the risk of occupational-disease-inductive factors in the workplace, and the results showed that the high risk level was 16.67%, the medium risk level was 63.33%, and the low risk level was 20.00%. The risk level of silicon dust is from low risk to high risk. Conclusion: The semi-quantitative assessment method and the occupational health risk assessment method of the International Commission on Mining and Metals are simple to operate and practical, and are suitable for the assessment of occupational hazards in ceramic enterprises.

[Study on determination of ethylal in workplace air by gas chromatography].

Objective: A solvent desorption-gas chromatography method for determination of ethylal in workplace air has been established. Methods: Ethylal in workplace air was collected by activated carbon tube and desorbed with carbon disulfide, and the desorption solutions were analysed by capillary column GC with FID detector. Results: The method presented a good linearity in the range of 0.87~34 800.00 mg/L of ethylal in the standard solution, with the correlation coefficient being r=0.999 7. The limit of detection and the limit of quantification of this method were respectively 0.20 mg/L and 0.80 mg/L, and the minimum detectable concentration and the minimum quantification concentration of this method were respectively 0.17 mg/m(3) and 0.60 mg/m(3) per 1.50 L of air.The within-run precision of the method was 2.93%-6.20%, and the between-run precision 3.67%-6.44%. The desorption efficiency between 94.22%-97.27%. Ethylal in activated carbon tube could be kept at least 7 days at room temperature without significant loss. Conclusion: The method could be used for determination of ethylal in workplace air.

Genetic variability of Myzus persicae nicotianae densovirus based on partial NS and VP gene sequences.

We previously described a novel densovirus [Myzus persicae nicotianae densovirus (MpnDV)] infecting M. persicae nicotianae (Hemiptera: Aphididae) with 34% prevalence. This single-stranded DNA virus has a 5480-nucleotide ambisense genome and belongs to the Densovirinae subfamily within the family Parvoviridae. In the present study, we estimated the genetic diversity of MpnDV using partial nonstructural protein (NS) and capsid protein (VP) gene sequences from 10 locations in China. First, we identified MpnDV-positive samples by amplifying a 445-bp fragment with primers MpDVF/MpDVR. Subsequently, we amplified and sequenced COI genes with primers MpCOIF/ MpCOIR, and partial NS and VP sequences with primers MpnDVF1/MpnDVR1. The respective 655-, 1461-, and 423-bp COI, NS, and VP fragments were used to analyze the genetic diversity of MpnDV using MEGA 6.0 and DnaSP 5.0. The high level of identity shared by all COI sequences (>99%) suggested that the aphids sampled were of the same species, and indicated population homogeneity across the 10 locations investigated. The nucleotide diversity of MpnDV sequences (0.0020 ± 0.0025) was significantly higher than that of the COI genes (0.0002 ± 0.0005). The pairwise fixation index for MpnDV was 0.832, and the total gene flow was 0.05. Phylogenetic analysis revealed that the MpnDV haplotypes clustered according to geographical location, except for those from the Liaoning and Shanxi provinces. In conclusion, MpnDV demonstrated a low level of gene flow and high genetic diversity, suggesting that it is vertically transmitted, and implying that endosymbiotic viruses could be used as markers in studies of insect population genetics.