Transarterial chemoembolization plus a PD-1 inhibitor with or without lenvatinib for intermediate-stage hepatocellular carcinoma.

AIM: Transarterial chemoembolization (TACE) combined with a PD-1 inhibitor and TACE combined with a PD-1 inhibitor and lenvatinib have recently been reported as promising treatments to improve the prognosis of hepatocellular carcinoma (HCC) patients. This study aims to compare the efficacy of these two treatments. METHODS: A retrospective study was conducted, and patients were recruited from two centers in China. Progression-free survival (PFS) and overall survival (OS) were compared, and the objective response rate (ORR) and disease control rate (DCR) were evaluated according to the modified Response Evaluation Criteria in Solid Tumors (mRECIST). Treatment-related adverse events (AEs) were analyzed to assess safety. RESULTS: The median follow-up for the entire cohort was 11.4 months. Of the 103 patients included in this study, 56 received triple therapy, and 47 received doublet therapy. PFS was significantly higher in the triple therapy group than in the doublet therapy group (mPFS 22.5 vs. 14.0 months, P < 0.001). Similar results were obtained in terms of OS (P = 0.001). The ORR and DCR were also better in the triple therapy group (64.3% vs. 38.3%, P = 0.010; 85.7% vs. 57.4%, P = 0.002). The most common AEs in the triple therapy group were decreased albumin (55.3%), decreased platelet count (51.8%) and hypertension (44.6%). CONCLUSIONS: The combination of TACE with a PD-1 inhibitor and lenvatinib in patients with BCLC stage B HCC might result in significantly improved clinical outcomes with a manageable safety profile compared with TACE with a PD-1 inhibitor.

Multifractal Characteristics Analysis of Spatial State of Prefecture-Level Cities in China.

In the last 40 years, Chinese cities have seen extensive development across a wide array of spheres. In this study, we applied a power-law and multifractal analysis to characterise 22 indices for 288 prefecture-level cities in mainland China. The data used to characterise the indices is representative of the year 2012. The results show that the Gross domestic product (GDP) is regular and exhibits multifractal spatial characteristics. Specifically, most developmental fields exhibit coupling in conjunction with being chaotic. Furthermore, eight indices with multifractal characteristics clearly reflect the spatial complexity of the corresponding fields and the volatility between prefecture-level cities. Overall, the tertiary industry has undergone nongeneralised development. On the other hand, the construction industry resembles a bubble economy, and the spatial layout of traditional industries has a homogenising effect in Middle and East China. This study examines China's overall spatial characteristics and states based on the above-mentioned analyses; additionally, the study focuses on the early 2010s. The contribution of this study provides a quantitative analysis paradigm based on a multifractal approach.

Preparation of asymmetric particles by controlling the phase separation of seeded emulsion polymerization with ethanol/water mixture.

Alcohols are discovered for the first time to tune the morphology of poly(vinyl benzyl chloride)-poly(3-methacryloxypropyltrimethoxysilane) (PVBC-PMPS) composite particles through seeded emulsion polymerization within the alcohol/water mixture. Here, monodispersed linear PVBC particles was synthesized through the dispersion polymerization and employed as the seeds. The as-obtained PVBC-PMPS composite particles could be dramatically tuned from core-shell structures to snowman-like particles, to dumbbell-shaped particles, to inverse snowman-like particles when the ethanol content in reaction mixtures is only adjusted within a narrow range. The morphology of fresh PMPS bulges was observed after removing the linear PVBC seeds with N,N'-dimethyl formamide, and their formation mechanism was studied by monitoring the free radical polymerization and sol-gel process of 3-methacryloxypropyltrimethoxysilane. It has been confirmed that the sol-gel kinetics were the main factor on the particles' morphology. In addition, morphologies of PVBC-PMPS particles were also varied by the MPS feeding amount, types of the co-solvent and pH values of alcohol/water mixtures.

[Study on the optimal extaction of total flavonoids from Tagetes erecta by central composite design-response surface methodology].

OBJECTIVE: To optimize the process of extracting total flavonoids from Tagetes erecta. METHODS: The influential factors were extraction temperature, ethanol concentration, reflux time and solvent volume fold. The evaluating indicator was the extraction rate of total flavonoids from Tagetes erecta. The central composite design-response surface methodology was used to optimize the process and the prediction was carried out. RESULTS: The optimum conditions of extraction were 80% ethanol, 2.5 hours for reflux, 35 volume folds of solvent and 70 degrees C. CONCLUSION: It shows that the optimum model is simple and highly predictive.

Risk factors and prognosis of recurrence within 6 months after radical resection of intrahepatic cholangiocarcinoma / 中华普通外科杂志

Objective:To explore the relevant risk factors and prognosis of patients with intrahepatic cholangiocarcinoma (ICC) who experienced recurrence within 6 months after surgeryMethods:This retrospective study included a total of 259 patients with ICC a treated at He'nan Provincial People's Hospital and He'nan Cancer Hospital from Jan 2018 to Jan 2020. The clinical and pathological data ,differences between the group with recurrence within 6 months and the group without recurrence within 6 months were compared using the chi-square test. Logistic regression analysis was used to determine the relevant risk factors for recurrence within 6 months. Kaplan-Meier method was used to construct survival and recurrence curves, and survival rates were calculated.Results:The overall survival and recurrence-free survival of patients in the group with recurrence within 6 months were significantly shorter. CA19-9, tumor longitudinal diameter, microvascular invasion, and neural invasion were identified as independent risk factors for recurrence within 6 months after ICC surgery ( P<0.001). Conclusion:The patient population experiencing recurrence within 6 months after ICC surgery has an extremely poor prognosis and possesses a specific tumor microenvironment. CA19-9, tumor longitudinal diameter, microvascular invasion, and neural invasion were identified as independent risk factors for recurrence within 6 months after ICC surgery.

Cadmium promotes senescence of annulus fibrosus cells via activation of PI3K/Akt signaling pathway / 中国组织工程研究

BACKGROUND:Cadmium is a common environmental pollutant,which can damage multiple organs and tissues,such as the kidney and bone,but its effect on annulus fibrosus cells in the intervertebral disc has been less reported. OBJECTIVE:To investigate the effect of cadmium chloride on the senescence of annulus fibrosus cells and the role of PI3K/Akt signaling pathway. METHODS:Annulus fibrosus cells from Sprague-Dawley rat intervertebral discs were harvested and passage 3 cells were intervened with different concentrations of cadmium chloride(0,1,5,10,20 μmol/L).Cell viability and proliferation were detected by cell counting kit-8 assay.Transcriptome sequencing and Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis were performed on annulus fibrosus cells with or without cadmium chloride addition.Passage 3 annulus fibrosus cells were divided into control group,cadmium chloride group and LY294002 group.Cell proliferation rate was detected by EdU method,positive cell rate was detected by senescence-associated β-galactosidase staining,and expressions of senescence-associated proteins(p16,p21 and p53)and p-Akt at protein and mRNA levels were measured by western blot,RT-PCR and immunofluorescence. RESULTS AND CONCLUSION:5 μmol/L cadmium chloride could inhibit the proliferation of annulus fibrosus cells.Results from the Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis showed that the main signal transduction pathways included PI3K/Akt,cell cycle and p53 signaling pathways,which were related to cell senescence and proliferation.PI3K/Akt signaling pathways with significant differential expression were selected for validation.Compared with the control group,the EdU-positive rate was significantly decreased in the cadmium chloride group(P<0.05),while the β-galactosidase-positive rate,the expression of senescence-associated proteins(p16,p21 and p53)and p-Akt significantly increased(P<0.05).Compared with the cadmium chloride group,the EdU-positive rate and p-Akt expression were significantly decreased in the LY294002 group(P<0.05),while the β-galactosidase-positive rate and the expression of senescence-associated proteins(p16,p21 and p53)significantly increased(P<0.05).To conclude,cadmium chloride can regulate the senescence of annulus fibrosus cells by activating the PI3K/Akt signaling pathway,thereby inducing the occurrence and progression of intervertebral disc degeneration.

Clinical Characteristics and Use of Traditional Chinese Medicine Therapy in 222 Malignant Tumor Cases with COVID-19： A Retrospective Study / 中医杂志

ObjectiveTo analyze the clinical characteristics and the use of traditional Chinese medicine （TCM） therapy in cancer patients with COVID-19， and to provide reference for making TCM prevention and treatment strategies and determining diagnosis and treatment priorities for patients with malignant tumors in the COVID-19 epidemic. MethodsThe medical records of 225 malignant tumor cases with COVID-19 who were admitted to 7 national research centers from January 1st to 20th， 2023 were retrospectively collected， and the main symptoms and duration after infection， nucleic acid negative conversion time， use of TCM therapy， and changes in adverse reactions after resuming anti-tumor treatment were analyzed. ResultsA total of 222 malignant tumor patients with COVID-19 were included in the analysis， involving 205 mild cases and 17 moderate cases. The top four most frequently reported clinical symptoms were fever （165 cases）， expectoration or dry cough （99 cases）， decreased appetite （95 cases） and fatigue （85 cases）， of which 40 expectoration or dry cough cases ， 37 fatigue cases and 29 decreased appetite cases lasted for more than 14 days. One hundred and five patients with nucleic acid detection report had a median negative conversion time of 14 days. The nucleic acid negative conversion time was significantly longer in patients with lung cancer compared to those with digestive system malignant tumors， and in those with myelosuppression than those without （P＜0.01）. During the infection period， 47.30% （105/222） of the patients used Chinese patent medicine， and 21.17% （47/222） were treated with herbal decoctions. The use of TCM in patients during the prevention and rehabilitation period， was 1.80%（4/222） and 7.21%（16/222）， respectively. Fifty-five patients resumed anti-tumor treatment after nucleic acid negative conversion， and received TCM simultaneously. Observed adverse reactions， including gastrointestinal reactions， bone marrow suppression， and neurotoxicity， were all grade 1 to 2， and no new adverse events occurred during follow-up. ConclusionCertain malignant tumor patients with COVID-19 had prolonged symptoms and nucleic acid negative conversion time Rational use of TCM can help to promote the rehabilitation of the patients and ensure the smooth process of anti-tumor treatment after infection.

Construction and evaluation of a predictive nomogram model for the prognosis of intrahepatic cholangiocarcinoma patients undergoing curative resection based on the albumin-bilirubin score and tumor burden score grade / 中华肝胆外科杂志

Objective:A predictive nomogram model for the prognosis of intrahepatic cholangiocarcinoma (ICC) patients after curative resection was constructed based on the albumin-bilirubin score and tumor burden score (ATS) grade, and the predictive performance of the nomogram model was evaluated.Methods:Retrospective analysis of clinical data was made, from ICC patients who underwent curative resection at Zhengzhou University People's Hospital and Zhengzhou University Cancer Hospital from January 2016 to January 2020. A total of 258 patients were included in the study, with 140 males and 118 females, with an average age of (56.5±9.5) years. The 258 ICC patients were randomly divided into a training set ( n=174) and a testing set ( n=84) in a 7∶3 ratio. Single-factor and multi-factor Cox regression analyses were performed to identify prognostic factors for ICC patients of the training set, and then a nomogram model was constructed. The performance of the nomogram model was evaluated by using the concordance index (C-index), calibration curve, and risky decision curve analysis. Results:In the training set, univariate Cox regression analysis indicated that albumin-bilirubin (ALBI), tumor burden score (TBS), carcinoembryonic antigen (CEA), tumor differentitation, lymphvascular invasion and ATS significantly influenced overall survival after radical resection for ICC (all P<0.05). Multifactorial Cox regression analysis revealed that ATS grade, CEA, tumor differentiation, lymphovascular invasion, and AJCC N stage are independent risk factors for the prognosis of ICC patients after curative resection (all P<0.05). Assessment of the postoperative survival prediction model based on multifactorial Cox regression yielded a C-index of 0.775(95% CI: 0.747-0.841) for the training set and 0.731(95% CI: 0.668-0.828) for the testing set. The calibration curves for both the training and testing sets indicated strong predictive capability of the model. Additionally, the risk decision curve also suggested high net benefit of the model. Conclusions:The preoperative ATS grade is an independent factor affecting the survival after ICC radical resection. The nomogram model constructed based on ATS grade demonstrates excellent predictive value for postoperative prognosis in ICC patients.

Effect of atorvastatin combined with alendronate in the treatment of T2DM with osteoporosis on bone metabolism, TNF-α, IL-6, and 25- (OH) D levels / 中华内分泌外科杂志

Objective:To investigate the effects of atorvastatin combined with alendronate in the treatment of type 2 diabetes mellitus (T2DM) with osteoporosis (OP) on bone metabolism, tumor necrosis factor alpha (TNF-α) , interleukin 6 (IL-6) , and 25-hydroxyvitamin D[25- (OH) D] level.Methods:A total of 152 patients with T2DM and OP who were diagnosed and treated in our hospital from Jul. 2017 to Jul. 2020 were selected. According to the different treatment methods, they were divided into control group (73 cases with alendronate treatment) and study group (79 cases receiving atova Statins combined with alendronate sodium treatment) . The two groups were compared in terms of bone metabolism indexes, bone mineral density, changes in serum TNF-α, IL-6, 25- (OH) D levels, and adverse reactions before and after treatment.Results:After treatment, osteocalcin (BGP) , bone-specific alkaline phosphatase (BAP) , lumbar spine L1-4 bone mineral density, femoral neck bone mineral density, and 25- (OH) D of the two groups increased ( P< 0.001) , and the study group was significantly higher than the control group (BGP: 7.68±0.89 vs 6.88±0.93; BAP: 18.62±3.97 vs 16.82±3.24; lumbar spine L1-4: 0.95±0.08 vs 0.92±0.05; femoral neck: 0.79±0.07 vs 0.75±0.06; 25- (OH) D: 31.35±10.1 vs 26.54±7.14; all P<0.05) . After treatment, the serum type I collagen C-terminal peptide (s-CTX) , human tartrate acid phosphatase (TRAP-5b) , TNF-α, IL-6 were decreased for both groups ( P<0.001) , and they were significantly lower in the study group than those in the control group (s-CTX:0.37±0.12 vs 0.55±0.12; TRAP-5b: 2.43±0.66 vs 2.99±0.75; TNF-α: 9.93±1.91 vs 11.77±2.69; IL-6: 10.65±1.26 vs 12.91±1.21; all P<0.001) . The incidence of adverse reactions in the study group was significantly lower than that in the control group (16.46% vs 39.73%, P=0.001) . Conclusion:Atorvastatin combined with alendronate in the treatment of T2DM patients with OP can effectively increase 25- (OH) D levels, reduce inflammation, and promote bone metabolism and bone density.

Research progress in biological characteristics and influencing factors of jaw bone marrow mesenchymal stem cell / 中华口腔医学杂志

Jaw bone marrow mesenchymal stem cell (JBMMSC), which exists in the maxilla and mandible, is adult stem cells with strong proliferation ability and multiple differentiation potential. Pathological, physicochemical and biological factors can affect the biological characteristics of JBMMSC. Compared with bone marrow mesenchymal stem cells derived from long bone, the biological characteristics of JBMMSC are site-specific because of the different sources of tissue and osteogenesis of bone. The same influencing factors have different effects on these two kinds of cells. Besides, JBMMSC also has the advantages of easier access, less trauma and lower immunogenicity. It has broad application prospects in craniomaxillofacial defect repair, periodontal tissue regeneration, and improving the success rate after implantation and so on. It has attracted wide attention in the basic and clinical studies. However, the regulation mechanism of its proliferation and differentiation is not clear, which affects its application as seed cell. Therefore, this paper reviews the biological characteristics influencing factors of JBMMSC and application progress in clinical and basic research, aiming to provide reference for further research and clinical application.

Global characterization of modifications to the charge isomers of IgG antibody / 药物分析学报

Posttranslational modifications of antibody products affect their stability,charge distribution,and drug activity and are thus a critical quality attribute.The comprehensive mapping of antibody modifications and different charge isomers(CIs)is of utmost importance,but is challenging.We intended to quanti-tatively characterize the posttranslational modification status of CIs of antibody drugs and explore the impact of posttranslational modifications on charge heterogeneity.The CIs of antibodies were fraction-ated by strong cation exchange chromatography and verified by capillary isoelectric focusing-whole column imaging detection,followed by stepwise structural characterization at three levels.First,the differences between CIs were explored at the intact protein level using a top-down mass spectrometry approach;this showed differences in glycoforms and deamidation status.Second,at the peptide level,common modifications of oxidation,deamidation,and glycosylation were identified.Peptide mapping showed nonuniform deamidation and glycoform distribution among CIs.In total,10 N-glycoforms were detected by peptide mapping.Finally,an in-depth analysis of glycan variants of CIs was performed through the detection of enriched glycopeptides.Qualitative and quantitative analyses demonstrated the dynamics of 24 N-glycoforms.The results revealed that sialic acid modification is a critical factor ac-counting for charge heterogeneity,which is otherwise missed in peptide mapping and intact molecular weight analyses.This study demonstrated the importance of the comprehensive analyses of antibody CIs and provides a reference method for the quality control of biopharmaceutical analysis.

Numbers of positive lymph nodes predict postoperative survival of intrahepatic cholangiocellular carcinoma patients after radical resection / 中华普通外科杂志

Objective:To evaluate prognostic significance of metastated lymph nodes (LN) in patients with intrahepatic cholangio carcinoma (ICC) after radical resection.Methods:Data were reviewed on 90 patients at Department of Hepatobiliary and Pancreatic Surgery in our hospital from Feb 2013 to Oct 2019, 37 cases had no LN metastasis (N0 group), 21 cases were in N1 group (positive LN<3) and 32 cases in N2 group (positive LN≥3),and Kaplan-Meier method was used to construct survival curve. Univariate and multivariate COX regression analysis was used to screen independent risk factors.Results:In N0 group the 1-and 3-year survival rates were 57.7% and 35.2%, respectively. In N1 group the 1-and 3-year survival rates were 46.7% and 17.5%, respectively in N2 group. the 1-and 3-year survival rates were 19.6% and 0, respectively. There was statistical significance in overall survival rate among the three groups ( χ2=15.272, P<0.05). Multivariate analysis showed that resection margin ( P=0.009) and the number of positive LN ( P=0.002) were independent risk factors affecting the prognosis of patients. Conclusion:Resection margin and the number of metastasing LN were closely related to postoperative prognosis of ICC patients.

To study the extent of lymph mode dissection and prognostic factors in patients with intrahepatic cholangiocarcinoma / 中华肝胆外科杂志

Objective:To study the impact of patients with intrahepatic cholangiocellular carcinoma (ICC) who underwent surgical resection with or without lymph node dissection (LND), negative or positive lymph node metastasis detected by LND, different extents of LND, and prognostic factors on long-term prognosis of these patients.Methods:The clinical data of 162 patients who were admitted to the Affiliated Cancer Hospital of Zhengzhou University from June 2014 to October 2019 and underwent surgical resection with postoperative histopathological results confirming ICC were retrospectively analyzed. According to the degree of LND, these patients were divided into three groups: the undissected group ( n=68), N0 dissected group (prophylactic dissection) ( n=41) and N1 dissected group (positive dissection, n=53). Of 94 patients who underwent LND, 23 patients underwernt the first station LND (the routine dissection group, n=23), and 71 patients underwent extended LND (the extended dissection group, n=71). The Kaplan-Meier method was used to construct survival curves. Cox regression analysis was used to detect independent factors affecting survival and long-term prognosis of patients. Results:In this study, there were 87 males and 75 females, with a median age of 60 years.The median survival time of these 162 ICC patients was 10 months. The cumulative survival rates at 1-, 3- and 5-year after surgery were 37.6%, 16.5% and 7.9%, respectively. The 1-, 3- and 5-year cumulative survival rates of the N0 dissection group were 52.1%, 31.7% and 25.4%, respectively, which were significantly better than those of the undissected group (34.2%, 12.7%, 3.4%), and the N1 dissection group (30.3%, 11.4%, 0) ( P<0.05). There were no significant differences in postoperative survival between the extended dissection group and the routine dissection group ( P>0.05). Preoperative CA19-9 >50 U/ml ( RR=1.425, 95% CI: 0.962-2.112), maximum tumor diameter > 5 cm ( RR=0.672, 95% CI: 0.456-0.989), without LND ( RR=1.715, 95% CI: 1.140-2.580), positive margin ( RR=0.591, 95% CI: 0.390-0.897), and without postoperative adjuvant therapy ( RR=0.663, 95% CI: 0.504-0.872) were independent risk factors affecting postoperative survival ( P<0.05). Conclusions:LND in ICC patients improved long-term survival outcomes. However, extended LND did not improve prognosis of these patients. The preoperative CA19-9 level, maximum tumor diameter, lymph node dissection, surgical margin status, and postoperative adjuvant therapy were independent risk factors affecting long-term prognosis of these patients.

Case-control study on the Endobutton plate and clavicular hook plate for the treatment of acromioclavicular joint dislocation / 中国骨伤

OBJECTIVE@#To study the clinical efficacy and complications of Endobutton titanium plate and clavicle hook plate in the treatment of acromioclavicular dislocation.@*METHODS@#Total 48 patients with Rockwood Ⅲ to Ⅴ acromioclavicular joint dislocation from March 2015 to May 2019 were retrospectively divided into two groups according to different surgical methods. Among the patients, 23 patients were treated with Endobutton loop titanium plate fixation (observation group), including 15 males and 8 females, ranging in age from 23 to 59 years old, with an average of(36.2±8.1) years old;Rockwood type Ⅲ in 6 cases, type Ⅳ in 11 cases and type Ⅴ in 6 cases. Twenty-five patients were treated with clavicular hook plate(control group), including 17 males and 8 females, ranging in age from 22 to 54 years old, with an average of (34.7±6.4) years old; Rockwood type Ⅲ in 6 cases, type Ⅳ in 14 cases and type Ⅴ in 5 cases. The operation time, intraoperative bleeding, hospitalization time, visual analogue scale (VAS) of pain, Constant-Murley score of shoulder function and postoperative complications were compared between the two groups.@*RESULTS@#All the patients were followed up, and the duration ranged from 24 to 51 months, with a mean of (30.5±6.5) months. The amountof bleeding and hospitalization time in the observation group were (71.9±4.0) ml and(8.2±1.6) d respectively;and those in the control group were (97.6±13.4) ml and (12.8±1.2) d respectively. There was significant difference between the two groups (@*CONCLUSION@#Compared with clavicular hook plate internal fixation in the treatment of acromioclavicular joint dislocation, Endobutton loop titanium plate internal fixation technology has the advantages of less surgical bleeding, shorter hospitalization time, less postoperative pain, good recovery of shoulder joint function and less complications.

Determination of 12 kinds of chlorobenzene compounds in workplace air by portable gas chromatography-mass spectrometry / 中国职业医学

OBJECTIVE: To establish a method for simultaneous determination of 12 kinds of chlorobenzene compound(CBs) in workplace air using portable gas chromatography-mass spectrometry(GC-MS) technique. METHODS: The GDH-3 air sampling tube was developed independently, and were used to collect the 12 kinds of CBs in the vapor state and aerosol state in the air. After elution with toluene solvent, portable GC-MS method was used for detection. Fast chromatographic column was used for separation, and then qualitatively analyzed with retention time and characteristics of the ions, and quantitative analyzed by standard curves. RESULTS: The quantitative determination ranges of the 12 kinds of CBs were 0.20-200.00 mg/L. All the correlative coefficients were greater than 0.998 3. All the minimum quantitative concentration was 0.01 mg/m~3, and all the minimum quantitative mass concentration was 0.04 mg/m~(3 )(15 L sample). The average elution efficiency was 88.97%-116.86%. The within-run and the between-run relative standard deviation was 10.15%-13.48% and 12.87%-19.66%, respectively. All the sampling efficiencies were>90.00%. CONCLUSION: The portable GC-MS technique could be used for rapid qualitative and quantitative detection of 12 kinds of CBs in workplace air.

Preparation of air sampling tube for chlorobenzene compounds and establishment of its matching detecting method / 中国职业医学

OBJECTIVE: To prepare and develop a GDH-2 air sampling tube for detecting 12 kinds of chlorobenzenes(CBs) in workplace air and to establish a matching detecting method. METHODS: The self-developed GDH-2 air sampling tube was filled with ion exchange resin and activated carbon, and the mass ratio was 10 ∶1. The GDH-2 air sampling tube was used to collect 12 kinds of CBs with coexistence of gaseous and aerosol in the air. After elution with toluene, they were separated on a chromatographic column and determined by microcell electron capture detector. RESULTS: The quantitative detecting range of the method was 0.51×10~(-3)-6 000.00 mg/L, with the correlation coefficients greater than 0.999 4. The minimum detection concentration was 0.02-61.99 μg/m~3, and the minimum quantitative concentration was 0.05-206.62 μg/m~3. The average desorption efficiency was 90.8%-104.0%. The within-run relative standard deviation(RSD) was 1.0%-5.7%, and the between-run RSD was 3.0%-7.3%. The samples can be stored at room temperature for at least 26 days. CONCLUSION: The self-developed GDH-2 air sampling tube and its matching measuring method can be used for the collection and determination of the 12 kinds of CBs in the air of workplace.

Analysis on comparison of inter-laboratory results of chemical volatile organic compounds / 中国职业医学

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.

Determination of volatile organic compounds in air using portable gas chromatography-mass spectrometry / 中国职业医学

OBJECTIVE: To explore a method for detecting volatile organic compounds(VOCs) in air by a portable gas chromatography-mass spectrometer(GC-MS). METHODS: A portable GC-MS hand-held probe was used for sampling and detection. All effluent components were qualitatively analyzed by the standard spectral library of the United State National Institute of Standards and Technology. The percentage of peak area of the component was calculated by normalization method. The static distribution method was adopted in the semi-quantitative and quantitative analysis using nitrogen as the diluting gas to prepare different mass concentration of 13 kinds of VOCs in the mixed standard gas. The retention time and characteristic ions were used for qualitative analysis, and the quantitated full scanning mode was used for quantitative analysis.RESULTS: The minimum detected mass concentration of the 13 chemical harmful factors was 0.02-0.10 mg/m~3, and the minimum quantitative mass concentration was 0.07-0.38 mg/m~3. The recovery rate was 84.76%-116.56%, and the within-and between-run relative standard deviations were 4.10%-12.50% and 8.17%-14.36%, respectively. CONCLUSION: The portable GC-MS instrument could be used for qualitative alalysis, peak area percentage determination, semi-quantitative and quantitative analysis of VOCs in the workplace air or sudden chemical poisoning accidents.

Determination of methyl pentane in workplace air by solvent desorption-gas chromatography / 中国职业医学

OBJECTIVE: To establish a solvent desorption-gas chromatography method for determination of methyl pentane in workplace air. METHODS: Methyl pentane in workplace air was collected with activated carbon tube and desorbed with carbon disulfide, then separated by DB-1 capillary column, detected by flame ionization detector, and quantified by standard curve method. RESULTS: Good linearity was obtained in the range of 1.98-6 600.00 mg/L with the correlation coefficient of 0.999 9. The minimum detection limit and the minimum quantification limit were 0.06 and 0.20 mg/L, respectively. The minimum detection concentration and minimum quantification concentration was 0.04 and 0.14 mg/m~3, respectively(calculated by collecting 1.5 L of air sample). The average desorption efficiency was 97.3%-102.2%. The within-run relative standard deviation(RSD) and the between-run RSD were 0.4%-0.9% and 0.3%-3.0%, respectively. The sampling efficiency was 96.7%-100.0% and the penetration capacity was 8.68 mg. The samples can be stored at room temperature for at least 14 days. CONCLUSION: This method is suitable for methyl pentane detection in workplace air.

Molecular mechanism of miR-497 in regulating the schizophrenia susceptibility gene EFNB2 / 西安交通大学学报(医学版)

Objective: To verify whether EFNB2 gene is targeted by miRNA-497 using molecular biology methods. Methods: Bioinformatic method predicted that EFNB2 gene is targeted by miRNA-497. PCR methods amplified the fragment in EFNB2 gene 3'-UTR including the putative miRNA-497 binding site. Then the sequences of wide type (WT) and mutant (MUT) were cloned into the pmirGLO luciferase vector, respectively. The DNA sequences of the amplified fragments were identified by restriction enzyme digestion and sequencing, and were consistent with the reference sequence from UCSC. This constructed vector was marked as pmirGLO-EFNB2 vector. Finally, the pmirGLO vector, the pmirGLO-EFNB2 vector, miRNA-497 mimics and negative control (NC) were divided into five groups and transfected into HEK393T cells, and the luciferase activity was tested after 24 h and 48 h by dual luciferase reporter gene assay. Results: The results of DNA sequencing demonstrated that the PCR fragment was successfully cloned into pmirGLO vector. The transfection results showed that the recombinant plasmid of WT and MUT was successfully transfected into HEK293T. The results of dual luciferase activity assay demonstrated that miRNA-497 significantly decreased the reporter gene activity compared with the NC. Conclusion: At the cellular level, the schizophrenia susceptibility gene EFNB2 was verified to be targeted by miRNA-497, which provides a new idea and new clue for subsequent studies on miRNA-497 function in the molecular mechanism of schizophrenia.