OBJECTIVETo develop a solvent desorption gas chromatographic method for determination of n-pentanol in the workplace air.

METHODSn-Pentanol in the workplace air was collected with activated carbon tubes, desorbed with 2% 2-propanol in carbon disulfide, separated with a nitroterephthalic acid-modified FFAP capillary column, and detected with flame ionization detector.

RESULTSThe limit of detection was 0.2 mg/L; the lower limit of quantification was 0.6 mg/L; the linear range was 0.6-4072.0 mg/L. The minimum detectable mass concentration was 0.2 mg/m3 for 1.5 L of air sample. This method was highly repeatable. The relative standard deviations were 2.3%-5.4%. The average desorption efficiencies were 86.9%-94.2%. The absorption efficiencies were 100%. The breakthrough volume was above 8.0 mg in 100-mg activated carbon. The samples in activated carbon tubes could be stored for at least 14 days at room temperature.

CONCLUSIONThe method is feasible for determination of n-pentanol in the workplace air.

2-Propanol ; Air Pollutants, Occupational ; analysis ; Carbon Disulfide ; Charcoal ; Chromatography, Gas ; Limit of Detection ; Pentanols ; analysis ; Solvents ; Workplace

Objective: To explore weather microRNA let-7c (miR-let-7c) could regulate myotrophin gene expression in rat’s H9c2 cardiac myocytes with possible mechanisms.
Methods: Recombinant plasmid carrying 3′ untranslated region (3′-UTR) of myotrophin and miRNA precursor of let-7c was co-transfected into Hela cells to construct the luciferase reporter system in order to measure luciferase activity. Rat’s H9c2 cardiac myocytes were cultured. The let-7c gene expression was detected by Taqman probe-based real-time PCR after let-7c miRNA precursor or let-7c miRNA inhibitor transfection respectively; protein expressions of myotrophin and nuclear factor-κB (NF-κB) were examined by Western blot analysis.
Results: Luciferase activity examination indicated that compared with recombinant luciferase gene expression carrier (pMIR-MTPN)+miR precursor negative control group, pMIR-MTPN+miR-let-7c miRNA precursor group showed reduced luciferase activity (59.30±9.90) % vs (98.10±15.10) %. Western blot analysis presented that compared with miR negative control group, miR-let-7c precursor group had decreased protein expressions of myotrophin (0.28±0.05) vs (0.90±0.09) and NF-κB (0.25±0.06) vs (0.75±0.07); in contrast, compared with Negative inhibitor group, miR-let-7c inhibitor group had increased protein expressions of myotrophin (1.14±0.09) vs (0.44±0.09) and NF-κB (1.09±0.05) vs (0.71±0.06), allP<0.05.
Conclusion: miR-let-7c could inhibit myotrophin expression via acting on its 3′-UTR domain and may also inlfuence NF-κB signaling pathway in rat’s H9c2 cardiac myocytes.

be diagnosed by imaging examination before operation.The ALT patients with large or symptomatic adrenal lipomatous lesions or preoperatively diagnosed teratoma should be given surgical treatment.

Environmental Monitoring ; methods ; Gas Chromatography-Mass Spectrometry ; methods ; Humans ; Industry ; Volatile Organic Compounds ; analysis

Objective To propose a new diagnostic criterion for rosacea based on the analysis of clinical features of rosacea in a large sample.Methods A total of 1 090 Chinese outpatients with rosacea were enrolled from Department of Dermatology of Xiangya Hospital,and their demographic data,clinical manifestations and subjective symptoms were collected.According to results of descriptive analysis,clinical features of rosacea were summarized,and a new diagnostic criterion for rosacea was set up.Then,the sensitivity and specificity of the new diagnostic criterion were verified among 1 200 outpatients clinically characterized by facial erythema.Results Of 1 090 patients with rosacea,131 (12.0％) were male and 959(88.0％) were female,and the average age was 33.5 ± 11.1 years (range,10-66).Among the 1 090 patients,715 (65.6％) had initial lesions on the cheek,of whom,712 (99.6％) had intermittent flushing as the initial symptom,and 689 (96％) had sensitive skin symptoms such as dryness,burning and itching sensations;208 (19.1％) had initial lesions on the perioral region,of whom,204 (98.1％) had persistent erythema as the initial symptom;167 (15.3％) had initial lesions on the nose,of whom,163 (97.6％) had persistent erythema as the initial symptom;in addition,311 (28.5％) had lesions on the ocular region,and only 24 (2.2％) had lesions outside the face on the neck and retroauricular region.Based on these clinical features,a new diagnostic criterion for rosacea was proposed,including 1 major condition (intermittent flushing or persistent erythema on the cheek,perioral region or nose) and 5 minor conditions (1.sensitive skin symptoms such as burning,tingling,drying or itching sensations;2.telangiectasia;3.papules or pustules;4.hypertrophy;5.ocular symptoms).If with the major condition and at least one minor condition were met,patients could be diagnosed with rosacea.After verification among 1 200 patients with facial dermatitis clinically characterized by facial erythema,the new criterion was proved to have a sensitivity of 99.3％ and a specificity of 95.8％.Conclusion A new diagnostic criterion for rosacea with high sensitivity and specificity is proposed,which is worthy of clinical application.

Objective: To establish a method for determination of acetone, dichloromethane, hexane, 1, 1, 1-trichloroethane, 1, 2-dichloroethane, benzene, toluene, ethylbenzene etc organic compounds in urine by headspace gas chromatography-mass spectrometry (GC-MS) . Methods: Headspace gases of urine samples were injected into GC and determined by mass. Results: Determination of urine components were in a good linear range in their concentration range of this method. The correlation coefficients were between 0.996 and 1.000 with the detection limits between 0.1 μg/L and 4.5 μg/L, the precisions were between 1.3% and 4.6%, the recovery rates were between 86.2% and 97.4%. Conclusion This method has the advantages of low detection limits, high accuracy, high precision and simple pretreatment, which is suitable for the determination of the content of various volatile organic compounds in urine.

Objective To establish solvent desorption gas chromatographic method for determination of tert-butyl alcohol in the air of the workplace.Methods After tert-butyl alcohol in the air of the workplace collected with activated carbon tube and desorbed with 2％ 2-propanol in CS2,and then separated with DB-FFAP capillary column and detected with flame ionization detector.Results The linearity ranges were 0.6～2 264.0 mg/L.The limit of quantification was 0.6 mg/L.The determination has a good reproducibility.The intraassay and interassay precisions were 2.8％～3.2％ and 3.8％～5.7％.The desorption efficiencies were 93.9％～98.1％.Absorption efficiencies were 95.8％～100.0％.The breakthrough volume was above 7.1 mg in 100mg activated carbon.The samples in activated carbon tube could be stored for at least 14 days at ambient temperature.Conclusion The method is feasible for determination of tert-butyl alcohol in the air of the workplace.

Objective To establish solvent desorption gas chromatographic method for determination of tert-butyl alcohol in the air of the workplace.Methods After tert-butyl alcohol in the air of the workplace collected with activated carbon tube and desorbed with 2％ 2-propanol in CS2,and then separated with DB-FFAP capillary column and detected with flame ionization detector.Results The linearity ranges were 0.6～2 264.0 mg/L.The limit of quantification was 0.6 mg/L.The determination has a good reproducibility.The intraassay and interassay precisions were 2.8％～3.2％ and 3.8％～5.7％.The desorption efficiencies were 93.9％～98.1％.Absorption efficiencies were 95.8％～100.0％.The breakthrough volume was above 7.1 mg in 100mg activated carbon.The samples in activated carbon tube could be stored for at least 14 days at ambient temperature.Conclusion The method is feasible for determination of tert-butyl alcohol in the air of the workplace.

Objective:To evaluate the influence on the results and safety of double-balloon enteroscopy (DBE) at different combination time.Methods:Patients who received combined DBE procedures in Nanjing Drum Tower Hospital from April 2019 to August 2020 were divided into the one-day combination group and the non-one-day combination group. The complete enteroscopy rate, time of anterograde approach, time of retrograde approach, total time of combined approach, adverse events, hospital stay and cost were compared.Results:Among 119 patients who received DBE, 23 patients were excluded due to small intestinal stenosis. The complete enteroscopy rate was 92.9% (39/42) in the one-day group and 74.1% (40/54) in the non-one-day group, showing significant difference ( χ2=4.390, P=0.036). There were significant differences in the time of retrograde approach (35.59±23.29 min VS 55.10±19.04 min, t=-4.080, P<0.001), total time of combined approach (89.10±27.82 min VS 114.20±24.55 min, t=-4.254, P<0.001), hospital stay (9.24±3.76 d VS 11.76±4.41 d, t=-2.599, P=0.011) between the two groups. There were no significant differences in the time of anterograde approach, hospital cost or adverse events between the two groups. Conclusion:Combined DBE on one day yields a higher complete enteroscopy rate, less examination time and less hospital stay, which is worth of clinical application.