1.Optimization of the extraction process of Shenye buyi formula
Yanrao WU ; Mingming YU ; Xiaojing NIU ; Xiaoying DUAN
China Pharmacy 2026;37(12):1573-1578
OBJECTIVE To optimize the extraction process of Shenye buyi formula. METHODS Based on the quality by design (QbD) concept, the contents of rutin, nuciferine, sinapine thiocyanate, liquiritin,and glycyrrhizic acid ammonium salt, as well as the extract yield, were selected as the critical quality attributes (CQAs) for the extraction process of Shenye buyi formula. The fishbone diagram combined with the failure model and effect analysis method was adopted to determine the water addition, extraction time and extraction times as critical process parameters (CPPs). High-performance liquid chromatography was employed to detect the contents of rutin, nuciferine, sinapine thiocyanate, liquiritin, and glycyrrhizic acid ammonium salt. The analytic hierarchy process-entropy weight method was used to comprehensively assign weights to the content of the five components including rutin and the extract yield. The Box-Behnken response surface method was employed to fit the mathematical model between CQAs and CPPs, screen the operational space of the extraction process, and validate it. RESULTS The optimal operational space of the extraction process was 9.5 to 12 times the amount of water added, the extraction time was 1 to 1.7 hours, and the extraction times were 3. Upon verification,the comprehensive scores of the optimal extraction process within the operational space were 89.79 and 84.93, respectively. CONCLUSIONS The extraction process of the Shenye buyi formula can be applied to the development and production of its granule preparations.
2.Association of adverse childhood experiences with psychopathology, sleep, and cognitive function in children: the mediating role of putamen volume
Mengting ZHANG ; Min XIE ; Jiashuo ZHANG ; Xiaoying MA ; Menghan WEI ; Yubing YIN ; Yang CHEN ; Yulu WU ; Qiang WANG
Sichuan Mental Health 2026;39(3):263-273
BackgroundAdverse childhood experiences (ACEs) are strong predictors of psychopathology across the lifespan, exerting extensive adverse effects on physical and mental health during early development. While ACEs increase the risk of childhood psychopathology, sleep quality and impair cognitive function, the early neurobiological mechanisms mediating ACE-induced cognitive impairment remain unclear. ObjectiveTo explore the association between ACEs exposure and the risk of psychopathology, sleep disorders, and cognitive function, and to examine the mediating role of the putamen volume in the relationship between ACEs and cognitive function from a neurodevelopment perspective. MethodsData were obtained from the Adolescent Brain Cognitive Development (ABCD) study, comprising 10 572 children aged 9 to 10. Participants were categorized into five groups based on the cumulative score of ACEs reported by their parents and the children themselves: no-exposure group (0 types of ACEs), the one-exposure group, the two-exposure group, the three-exposure group, and the high-risk exposure group (≥ 4 types of ACEs). Logistic regression analysis was employed to evaluate the association between ACEs and psychopathological symptoms [T score of the Child Behavior Checklist (CBCL) ≥ 65]. Multiple linear regression analysis was ultilized to analyze the correlations between ACEs and the scores of the Sleep Disturbance Scale for Children (SDSC), the NIH Toolbox Cognition Battery (NIHTB-CB), as well as the multiple structures in the cerebral cortex and subcortex. The Bootstrap method was applied to test the mediating effect of the putamen volume between ACEs and neurocognitive function. ResultsAfter adjusting for confounders, ACEs cumulative score was correlated with children's psychopathological symptoms in a dose-response manner. Compared with the no-exposed group, the high-risk exposure group had a 2.08-fold (OR=2.080, 95% CI: 1.401–3.088) increased risk of internalizing problems and a 3.13-fold (OR=3.132, 95% CI: 1.703–5.760) increased risk of externalizing problems, and the risk of conduct problems was 4.68 times that of the no-exposed group (OR=4.681, 95% CI: 2.528–8.669). ACEs cumulative score positively predicted the total score of SDSC (β=0.080, 95% CI: 0.059–0.102), with relatively stronger predictive effects on sleep-wake transition disorder (β=0.086, 95% CI: 0.063–0.109) and sleep onset and maintenance disorder (β=0.066, 95% CI: 0.043–0.089). In terms of neurocognition and brain structure, ACEs cumulative score negatively predicted the overall cognitive composite score (β=-0.025, 95% CI: -0.050–-0.001), the crystallized cognitive composite score (β=-0.035, 95% CI: -0.060–-0.010), the volume of the left putamen nucleus (β=-0.025, 95% CI: -0.046– 0.003), and the volume of the right putamen nucleus (β=-0.023, 95% CI: -0.044– 0.003). The total putamen volume played a partial mediating role between ACEs and the overall cognitive composite score, the effect value was -0.002 (95% CI: -0.004–-0.001), accounting for 7.49% of the total effect. ConclusionACEs exposure may increase the risk of psychopathological and sleep disturbances in children and may impair neurocognitive function. Reduced putamen volume may serve a potential neurobiological pathway underlying the impact of ACEs on childhood cognition. [Funded by National Natural Science Foundation of China-Young Scientists Program (number, 82401763); Sichuan University West China Hospital Full-time Postdoctoral Research and Development Fund Project (number, 2023HXBH084)]
3.Expert consensus on in-hospital transfer safety management for patients undergoing invasive mechanical ventilation
Jie XIONG ; Hong SUN ; Xiaoying WU ; Xin GUAN ; Liming LI ; Li ZHANG ; Yongming TIAN
Chinese Journal of Nursing 2025;60(17):2053-2056
Objective To establish an expert consensus on in-hospital transfer safety management for patients undergoing invasive mechanical ventilation,providing guidance for clinical medical teams to conduct standardized transfers,reduce transfer risks,and ensure patient safety.Methods Through systematic searching,screening,evaluation,and summary of evidence related to in-hospital transfer safety management for patients on invasive mechanical ventilation,we extracted recommendations to form a preliminary draft of the expert consensus.From July to October 2024,totally 2 rounds of expert consultations,and 2 rounds of expert reviews were conducted,and the content was refined and finalized based on expert feedback.Results The final consensus encompasses 9 aspects,including transfer assessment and decision-making,pre-transfer preparation of medical staff,pre-transfer patient preparation,pre-transfer equipment preparation,pre-transfer medication preparation,monitoring and intervention during transfer,emergency events and management,transfer handover and documentation,and post-transfer management.Conclusion This consensus demonstrates strong practicality and operability,offering professional guidance for enhancing the safety of in-hospital transfers for patients on invasive mechanical ventilation.
4.Sinicization and reliability and validity test of the Obsessive and Compulsive Behaviors Scale of Mothers in Postpartum Period Regarding Baby Care
Hangcheng LIU ; Xixi LI ; Xiaoying ZHONG ; Haoyue GAN ; Hongjin WU ; Linqian HE ; Fang YANG
Chinese Journal of Practical Nursing 2025;41(2):103-111
Objective:To sinicize the Obsessive and Compulsive Behaviors Scale of Mothers in Postpartum Period Regarding Baby Care (OCBS-MPPRBC) to test its reliability and validity, and to provide an evaluation tool for evaluating the degree of compulsive behaviors of postpartum mothers regarding baby care.Methods:Following the principles of Brislin translation, back translation and cross-cultural adaptation, the Chinese version of OCBS-MPPRBC was formed. A convenient sampling method was used to investigate 360 women in Mianyang Central Hospital from November 2023 to February 2024, and to test the reliability and validity of the Chinese version OCBS-MPPRBC. The critical ratio method and the total correlation analysis method were used for item analysis, the reliability test was based on Cronbach α coefficient and half-reliability method, and the content validity index, exploratory factor analysis, confirmatory factor analysis and aggregate validity were used for validity test. Results:A total of 352 women aged 21-41 (31.55 ± 3.17) years who met the exclusion criteria were included. The Chinese version of OCBS-MPPRBC contained 9 items, and 2 common factors were extracted by exploratory factor analysis, and the cumulative total variance contribution rate was 65.523%. The content validity index of the scale level was 0.89, the content validity index of each item level was 0.86-1.00, and the Cronbach α coefficient of the total scale was 0.844, and the half-folded reliability was 0.759. The results of confirmatory factor analysis showed that the fitting index of the Chinese version of the OCBS-MPPRBC model was better. Conclusions:The Chinese version of the OCBS-MPPRBC scale has good reliability and validity, and has good operability, which can be used to evaluate the degree of compulsive behavior of postpartum mothers about baby care in China.
5.Effect of fenofibrate on right ventricular hypertrophy in rats with high-altitude heart disease and its mechanisms
Xiaoying ZHANG ; Qi SI ; Jiajia WU ; Shadi LI
Chinese Journal of Pathophysiology 2025;41(6):1153-1161
AIM:To investigate the effect of fenofibrate(FF)on the heart of rats with high-altitude heart dis-ease-induced right ventricular hypertrophy(H-RVH),and to explore the mechanisms and associated signaling pathways.METHODS:A total of 36 six-week-old male SD rats were randomly divided into control,model(H-RVH),and FF inter-vention(H-RVH+FF)groups with 12 rats each.A rat model of H-RVH was established by single subcutaneous injection of Sugen 5416(20 mg/kg)and exposure to a hypoxic condition(5 000 m above sea level)for 21 d in all groups except the control group.The rats in H-RVH+FF group were given FF(60 mg·kg-1·d-1)through gavage,while those in control and model groups received equal volume of saline once daily for 21 d.Rat heart gross morphology was observed,and the heart volume and weight,right ventricular weight and other hypertrophy indexes were measured in each group at the end of the experiment.A right heart floating catheter was used for measuring pulmonary artery and right ventricular pressure.Cardi-ac function was checked through cardiac ultrasonography.The serum levels of atrial natriuretic peptide(ANP),N-termi-nal pro-brain natriuretic peptide(NT-proBNP),free fatty acids(FFA),and myocardial tissue glucose(Glu)in all groups of rats were detected.The protein expression of peroxisome proliferator-activated receptor α(PPARα),fatty acid binding protein 1(FABP1),carnitine palmitoyl transferase 1a(CPT1a),pyruvate dehydrogenase kinase(PDK),and pyruvate dehydrogenase(PDH)were detected through Western blot.RESULTS:(1)Compared with the control group,the H-RVH group showed a significant increase in heart morphology and weight and increases in heart weight/body weight(HW/BW),heart volume,right ventricular weight/heart weight(RVW/HW),and Fulton index(FI)(P<0.05).Cardiac mor-phology,volume,heart weight,and HW/BW significantly decreased in the fenofibrate intervention group compared with the H-RVH group(P<0.05).RVW/HW and FI also decreased.(2)The right heart float catheter test showed that the mean right ventricular pressure(mRVP)and mean pulmonary artery pressure(mPAP)significantly increased in the H-RVH group compared with the control group(P<0.01).The increases in mRVP and mPAP were reversed in rats in the fe-nofibrate intervention group compared with the H-RVH group.(3)Cardiac ultrasonography showed that compared with the control group,the H-RVH group had significantly increased right ventricular anterior wall(RVAW)and right ventricular posterior wall(RVPW)thickness(P<0.01),significantly decreased right ventricular end-diastolic diameter(RVEDD),and right ventricular end-diastolic length(RVEDL)(P<0.01).In addition,pulmonary artery acceleration time(PAAT)was reduced,ejection time(PAET)was prolonged,and PAAT/PAET ratio decreased(P<0.01).Compared with the H-RVH group,the fenofibrate intervention group showed significant decreases in RVAW and RVPW(P<0.05),increases in RVEDD and RVEDL,and an increase in PAAT/PAET ratio.(4)The kit assay showed that the levels of ANP and NT-Pro BNP in serum were significantly higher in the H-RVH group than in the control group(P<0.05),while the levels of both were lower in the fenofibrate intervention group.The levels of serum FFA and myocardial tissue Glu levels(P<0.05)were significantly higher in the H-RVH group than in the control group.The levels of serum FFA and myocardial tissue Glu level were significantly lower in the fenofibrate intervention group than in the H-RVH group(P<0.05).(5)Western blot results showed that the expression levels of PPARα,FABP1,CPT1a,and PDH in the myocardial tissues of rats in the H-RVH group were significantly reduced(P<0.01),whereas the expression level of PDK significantly increased relative to those of the control group(P<0.01).All the effects on the above indices in the H-RVH group can be significantly re-versed by fenofibrate intervention(P<0.05).CONCLUSION:Fenofibrate exerts a protective effect on the hearts of rats with right ventricular hypertrophy associated with high-altitude heart disease by activating PPARα/FABP1/CPT1a,en-hancing fatty acid oxidation,inhibiting PDK,and activating PDH to promote the aerobic oxidation of glucose.Hence,the medication can ameliorate glucose-lipid metabolism disorders.
6.Expert consensus on integrated diagnosis and treatment techniques for oropharyngeal squamous cell carcinoma
Wei SHANG ; Haoyue XU ; Zongxuan HE ; Xiaoying LI ; Haijun LU ; Xiaohong ZHAN ; Dapeng HAO ; Yan SUN ; Wei GUO ; Zhangui TANG ; Guoxin REN ; Zhijun SUN ; Jian MENG ; Jie ZHANG ; Jichen LI ; Yue HE ; Chunjie LI ; Jianhua WEI ; Lizheng QIN ; Yaowu YANG ; Qing XI ; Wei WU ; Kai YANG ; Bing HAN ; Lingxue BU ; Shuangyi WANG ; Kai SONG ; Jiaqi ZHU ; Hongyu HAN ; Yu KONG ; Jieying LI ; Man HU ; Mingjin XU ; Moyi SUN
Journal of Practical Stomatology 2025;41(6):725-736
In recent decades,the incidence of human papillomavirus(HPV)-associated oropharyngeal squamous cell carcinoma(OPSCC)has shown a marked increase.Significant changes have also occurred in the OPSCC diagnosis and treatment paradigm.Deter-mining HPV status prior to treatment is now essential,and radiotherapy/chemotherapy,immunotherapy,and minimally invasive surgical techniques have progressively emerged as key modalities for managing OPSCC.However,alongside these paradigm shifts,a comprehen-sive technical consensus guiding the entire diagnostic and therapeutic process for OPSCC patients is currently lacking.Given China's large population base and the rising incidence of OPSCC,an expert panel convened to develop a clinical technical consensus on OPSCC diagno-sis and management tailored to China's specific context.This consensus aims to further enhance and standardize understanding of OPSCC management techniques among relevant healthcare professionals.
7.Expert consensus on in-hospital transfer safety management for patients undergoing invasive mechanical ventilation
Jie XIONG ; Hong SUN ; Xiaoying WU ; Xin GUAN ; Liming LI ; Li ZHANG ; Yongming TIAN
Chinese Journal of Nursing 2025;60(17):2053-2056
Objective To establish an expert consensus on in-hospital transfer safety management for patients undergoing invasive mechanical ventilation,providing guidance for clinical medical teams to conduct standardized transfers,reduce transfer risks,and ensure patient safety.Methods Through systematic searching,screening,evaluation,and summary of evidence related to in-hospital transfer safety management for patients on invasive mechanical ventilation,we extracted recommendations to form a preliminary draft of the expert consensus.From July to October 2024,totally 2 rounds of expert consultations,and 2 rounds of expert reviews were conducted,and the content was refined and finalized based on expert feedback.Results The final consensus encompasses 9 aspects,including transfer assessment and decision-making,pre-transfer preparation of medical staff,pre-transfer patient preparation,pre-transfer equipment preparation,pre-transfer medication preparation,monitoring and intervention during transfer,emergency events and management,transfer handover and documentation,and post-transfer management.Conclusion This consensus demonstrates strong practicality and operability,offering professional guidance for enhancing the safety of in-hospital transfers for patients on invasive mechanical ventilation.
8.Levels of peripheral blood lung cancer biomarkers in apparently healthy individuals in Beijing and surrounding areas and establishment and validation of reference intervals
Xinmiao LIU ; Ping SUN ; Mingyang HE ; Yan KANG ; Xiaoying LOU ; Yue WU ; Yulin SUN ; Hongjun GAO
Cancer Research and Clinic 2025;37(6):412-421
Objective:To explore the features of levels of lung cancer biomarkers in peripheral blood of adults in Beijing and surrounding areas, and establish personalized reference intervals for these biomarkers.Methods:A cross sectional study was conducted. The lung cancer biomarker data, including carcinoembryonic antigen (CEA), cytokeratin 19 fragment antigen 21-1 (CYFRA21-1), neuron specific enolase (NSE), progastrin-releasing peptide (ProGRP), and squamous cell carcinoma antigen (SCC-Ag), collected from adults who underwent cancer prevention examinations at the Cancer Hospital of the Chinese Academy of Medical Sciences from July 2021 to July 2022 were retrospectively analyzed. The interquartile range method was used to eliminate outliers, and the P95 value was calculated. Upper limit of 5 lung cancer biomarkers in different gender and age groups were obtained by referring to the reference intervals of quantitative analytes in the clinical laboratory (WS/T 402-2024). By analyzing the data of 208 adults who underwent cancer prevention physical examinations at the same center in June 2021 and 140 patients with benign lung masses confirmed by surgical resection pathology from January 2016 to June 2022, the established reference intervals for biomarkers were validated. Results:Two thousand six hundred and twenty-six cases of apparently healthy physical examiners were included for constructing reference intervals, including 1 456 males (55.4%) and 1 170 females (44.6%); the age range was 20-88 years old. The serum levels [ M ( Q1, Q3)] of CEA, NSE, ProGRP, SCC-Ag and CYFRA21-1 in 2 626 cases were 1.63 (1.07, 2.43) ng/ml, 13.08 (11.44, 14.77) ng/ml, 34.93 (29.02, 42.19) pg/ml, 0.80 (0.60, 1.00) ng/ml and 1.96 (1.48, 2.63) ng/ml, respectively. The serum levels of CEA [1.88 (1.22, 2.76) ng/ml vs. 1.41 (0.93, 2.02) ng/ml], NSE [13.31 (11.87, 15.00) ng/ml vs. 12.69 (10.96, 14.53) ng/ml], SCC-Ag [0.9 (0.7, 1.1) ng/ml vs. 0.7 (0.6, 0.9) ng/ml], and CYFRA21-1 [2.02 (1.53, 2.71) ng/ml vs. 1.87 (1.40, 2.51) ng/ml] in males were higher than those in females, and ProGRP [34.00 (28.25, 41.55) pg/ml vs. 36.12 (29.97, 42.98) pg/ml] was lower than that in females, and the differences were statistically significant (all P < 0.001). There were statistically significant differences in serum CEA levels between the groups of ≤ 40 years old (458 cases), >40-50 years old (827 cases), >50-60 years old (783 cases), >60-70 years old (412 cases), and >70 years old (146 cases) in pairwise comparison (all P < 0.05). Except for the age groups of ≤ 40 years old and >40-50 years old and the age groups of >60-70 years old and >70 years old, there were statistically significant differences in serum NSE levels among the other age groups in pairwise comparison (all P < 0.05). There were statistically significant differences in serum ProGRP levels between the 5 age groups (all P < 0.05). There were statistically significant differences when comparing the serum SCC-Ag level in the >40-50 age group, >50-60 age group and >60-70 age group with that in the ≤40 age group and >70 age group, respectively (all P < 0.05). However, there was no statistically significant difference between the other age groups in pairwise comparison (all P > 0.05). There were statistically significant differences in serum CYFRA21-1 levels between the 5 age groups (all P < 0.05). When gender and age were not distinguished, the P95 values of serum CEA, NSE, ProGRP, SCC-Ag and CYFRA21-1 levels were 4.44 ng/ml, 16.61 ng/ml, 57.65 pg/ml, 1.50 ng/ml, and 4.21 ng/ml, respectively. Considering gender and age, except for the >70 age group with no statistically significant difference in the P95 value of serum CEA level between males and females ( P > 0.05), the P95 value of serum CEA level in males was higher than that in females in all other age groups (all P < 0.001); the P95 values of serum CEA level in both males and females increased with age, but showed a decreasing trend in males over the age of 70. The P95 value of serum NSE level in males was higher than that in females in the age groups of ≤ 40 years and >40-50 years (both P < 0.05), while there was no statistically significant difference in the P95 value of serum NSE level between males and females in other age groups (all P > 0.05). The P95 values of serum NSE level in both males and females decreased firstly and increased later with age, reaching their highest levels at the age of >70. The P95 values of serum ProGRP level in females aged ≤ 40 and >50-60 were higher than those in males (both P < 0.05), while there was no statistically significant difference in the P95 value of serum ProGRP level between genders in other age groups (all P > 0.05); the P95 values of serum ProGRP level in both males and females increased with age. There was no statistically significant difference in the P95 value of serum SCC-Ag level between males and females in the ≤ 40 age group ( P > 0.05), while the P95 value of serum SCC-Ag level in males was higher than that in females in all other age groups (all P < 0.05). The P95 values of serum SCC-Ag level in males increased with age, while they were stable in females. There was no statistically significant difference in the P95 value of serum CYFRA21-1 level between males and females in the >60-70 age group ( P > 0.05), while the P95 value of serum CYFRA21-1 level in males was higher than those in females in all other age groups (all P < 0.05); the P95 values of serum CYFRA21-1 level in both males and females increased with age. Based on data from 2 626 apparently healthy physical examiners, reference intervals for the levels of 5 lung cancer biomarkers were constructed in different age groups of different genders. Validation was conducted on 208 physical examiners and 140 patients with benign lung lesions, and it was found that the compliance rate of using newly created reference intervals for different gender and age groups to interpret detection results was >90%, and the validation was passed. Conclusions:There are gender and age differences in the reference intervals of CEA, CYFRA21-1, NSE, ProGRP, and SCC-Ag in peripheral blood of adults in Beijing and surrounding areas. The constructed reference intervals of gender and age for biomarkers have been validated and shown good results, providing reference for optimizing the clinical application of lung cancer-related biomarkers.
9.Analysis of setup errors in dual-isocenter breath-hold radiotherapy after left-sided breast cancer surgery
Zhiqing XIAO ; Xiaotong LIN ; Miao WANG ; Yanqiang WANG ; Han GUO ; Lei TIAN ; Yanjiao WU ; Wenyan WANG ; Junling LIU ; Xiuwu LI ; Xiaoying XUE
Chinese Journal of Radiation Oncology 2025;34(5):468-475
Objective:To investigate the impact of different target sites, number of treatments, and age on setup errors in dual-isocenter radiotherapy for breast cancer, and to provide a basis for planning target volume (PTV) margin expansion.Methods:A retrospective analysis was conducted on data from 15 patients with left-sided breast cancer who underwent dual-isocenter breath-hold radiotherapy in the Department of Radiotherapy Oncology at the Second Hospital of Hebei Medical University from May 2021 to May 2023. Setup errors were acquired using a Varian TrueBeam STX linear accelerator. Patients were grouped by target site (supraclavicular/chest wall), treatment phase (early/late), and age (younger/older). Non-parametric tests were used to analyze differences in setup errors in : vertical (Vrt), longitudinal (Lng), lateral (Lat) directions, and pitch, roll, and rotation (Rtn) angles. The formula proposed by van Herk was applied to calculate PTV margins.Results:The Vrt direction setup error in the supraclavicular region (0.2 cm) was smaller than that in the chest wall region (0.26 cm), but errors and margin expansions in other directions were larger ( P<0.05 for Lng and Lat directions). No significant correlation was observed in Vrt direction errors between the two sites ( P=0.062), while significant correlations were found in the other directions and angles (all P<0.05). As treatment progressed, setup errors increased in the Vrt and Rtn directions for the supraclavicular region, and in the Vrt, Lng, Lat directions and Rtn angle for the chest wall region. Among these, only the increase in Lat direction error for the chest wall region was statistically significant ( P=0.028). The PTV margins in the late phase group (except for the Lat direction of the supraclavicular region) were greater than or equal to those in the early phase group. Elderly patients had significantly larger setup errors than younger patients in Vrt, Lng, and Lat directions for the supraclavicular region, as well as in Vrt and Lat directions for the chest wall region (all P<0.05). Conclusions:In dual-isocenter radiotherapy for breast cancer, the supraclavicular region requires larger PTV margins than the chest wall region, and elderly patients require greater margins overall. Mid-course rescanning is recommended. If cone-beam CT guidance cannot be ensured for every session, expansion of PTV margins should be considered for the supraclavicular region and elderly patients to reduce the risk of geographic miss.
10.Research on efficient ventilation protection measures for organic solvent in composite materials impregnation room
Xiaoying NAN ; Cang LIU ; Rongrong MENG ; Yafei XING ; Wenxia DU ; Yujia WU
Chinese Journal of Industrial Hygiene and Occupational Diseases 2025;43(6):417-421
Objective:To explore highly efficient ventilation protection technology for large-space workplaces adapted to the production process in composite material impregnation.Methods:A composite material impregnation room was selected as the research subject from August to December 2023. Occupational health investigation, on-site detection, and physical simulation of air distribution were used to analyze the distribution of the xylene concentrations in the impregnation room. In addition, the causes for excessive concentrations were analyzed, and the combination ventilation design of enclosed negative pressure cabinets and jet directional supply of fresh air was proposed. The concentration of xylene, the capture velocity and the differential pressure of ventilation facilities before and after the transformation were tested on the spot. The rationality of the airflow organization was determined through smoke testing, and the ventilation protection effects before and after the transformation were analyzed.Results:The time-weighted average allowable concentration ( CTWA) of xylene was reduced from 41.73 mg/m 3 to 7.78 mg/m 3, and the CTWA of xylene were reduced by 81.4%. The values of capture velocity at all areas were higer than 0.5 m/s, and the values of velocity unevenness in all regions were lower than or equal to 0.25. The differential pressure between the enclosed cabinet and the impregnation room corridor was -2 to -1 Pa. The overall velocity distribution at all areas was relatively uniform, the airflow organization was reasonable, and negative pressure was formed inside the enclosed cabinet. Conclusion:The combination ventilation design of xylene, the capture velocity and the differential pressure of ventilation facilities effectively reducing the xylene concentration in the workplace, and provide a reference for ventilation protection of xylene workplace.

Result Analysis
Print
Save
E-mail