A method was developed for determination of thirteen amines including seven aliphatic amines, two heterocyclic amines and four aromatic amines in atmospheric particulate matter (PM) by gas chromatography-mass spectrometry (GC-MS). Samples were ultrasonically extracted with ultra-pure water and derivatized with benzenesulfonyl chloride (BSC) under alkaline conditions. The derivatives were extracted with dichloromethane and then detected by GC-MS using DB-5MS chromatographic column. The method detection limit (S/N=3) and quantitation limit (S/N=10) were 0.00008-0.017 μg/mL and 0.00026-0.0565 μg/mL respectively, and the correlation coefficients were 0.9903-0.9996, which indicated that the standard curve had good linear correlation. In addition, the relative standard deviation was less than 30％ and the average recovery was 54.4％-159.7％ except for methylamine and benzylamine at spiked level of 1.0 μg/mL, showing high precision and accuracy. 9 kinds of amines were detected in the PM2.5 samples collected in Guangzhou city by this method, among which dimethylamine and butylamine accounted for 90％ of the total nine amines, which indicated that they were primary amines in PM2.5; while propylamine exhibited the lowest level in PM2.5 with the concentration less than 1.0 ng/m3.

ObjectiveWe conducted a drug resistance and homology analysis of diarrheagenic Escherichia coli （DEC） in Fengxian District of Shanghai in order to provide a basis for clinical rational drug use， risk monitoring and early warning. MethodsDEC were isolated from diarrheal patients in Fengxian District， Shanghai from 2019 to 2022. The minimum inhibitory concentrations （MIC） of 21 drugs to the DEC were determined. Genotyping and homology analysis were conducted with pulsed-field gel electrophoresis （PFGE）. ResultsThe DEC detection rate of diarrhea cases was 18.99% （131/690）， including enteroaggregative E.coli （EAEC） 64.89% （85/131）， enterotoxigenic E.coli （ETEC） 22.14% （29/131）， enteropathogenic E.coli （EPEC） 12.21% （16/131）， and enterohemorrhagic E.coli （EHEC） 0.76%（1/131）. The DEC detection showed obvious seasonal characteristics with a high incidence in summer. The DEC multidrug resistance rate was 66.41% with a total of 65 drug resistance profiles. The five antimicrobial drugs with the highest resistance rate were ampicillin （60.31%）， nalidixic acid （51.91%）， cefazolin （50.38%）， tetracycline （44.27%）， and cotrimoxazole （35.11%）. The rate of DEC resistance to levofloxacin was significantly increased from 2019 to 2022. Cluster analysis showed that the similarity of 85 EAEC cluster was 58.4%‒100.0%， and 69 band patterns were obtained. The similarity of 29 ETEC cluster was 58.5%‒100.0%， and 13 band patterns were obtained， including 2 dominant band types. The similarity of 16 EAEC clusters was 53.9%‒100.0%， and 15 band patterns were obtained. Five groups of homologous strains were found， consistent with the resistance phenotypes. ConclusionAmong the diarrhea cases， the DEC epidemic intensity is high， the drug resistance situation is severe， and the risk of outbreak infection is high in Fengxian District， Shanghai. Therefore， health monitoring and prevention need to be strengthened.

Objective To establish a HPLC method for glycine assay in the human thrombin. Methods The sample was derivatized with 2,4-dinitrofluorobenzene (DNFB). HPLC was performed on an ODS-C₁₈ column with 50% acetonitrile –0.05mol/L sodium acetate buffer (35:65) as the mobile phase. The flow rate was 1.0 ml/min and detection wavelength at 360 nm. Results The linear range of glycine was 0.006-0.030 mg/ml (r=0.999 6). The average recovery was 100.4%, with RSD 0.44% (n=9). Conclusion This method is simple, accurate and specific. It is suitable for glycine assay in human thrombin.

Objective To investigate the clinical features of patients with bronchiectasis of different types.Methods One hundred and twenty two patients with bronchiectasis at stable stage were recruited from January 2014 to July 2015.The patients were typed as cystic bronchiectasis (n =45) or non-cystic bronchiectasis (n =77) by high resolution CT (HRCT),expectoration bronchiectasis (n =80) or dry brochiectasis (n =42) by clinical symptoms,bacterial colonization (n =42) or non-bacterial colonization (n =80) by sputum culture.The modified British Medical Research Council (mMRC) dyspnea scale,Leicester Cough Questionnaire (LCQ),St George's Respiratory Questionnaire (SGRQ) and pulmonary function test were used to assess the clinical features,and the episodes of exacerbations and hospitalization,and mortality during 1-year follow-up were documented.Results mMRC dyspnea scale (1.90 ± 0.94 vs.2.90±1.09,t=-5.040),LCQ (16.20±4.60 vs.11.20±2.20,t=8.114),SGRQ (36.80±13.10 vs.52.06±22.10,t=-4.780),FEV1％ pred (68.45 ±26.50 vs.52.22 ±20.60,t=3.458),FVC％ pred (72.20 ±26.32 vs.63.10 ±21.42,t =2.058),FEV1/FVC (75.14 ±20.52 vs.58.12 ± 19.82,t =4.546),diffusing capacity of the lung for carbon monoxide (DLCO) (76.24 ± 28.40 vs.54.32 ± 21.20,t =4.400),episodes of exacerbations (Z =-8.272) and hospitalization during 1-year follow-up [6(14.29％) vs.29(36.25％),x2 =6.495] in patients with dry bronchiectasis were significantly better than those in patients with expectoration bronchiectasis (all P ＜ 0.05).mMRC dyspnea scale (3.20 ± 2.10vs.2.10±1.40,t=3.131),LCQ (10.12±2.63vs.16.22 ±3.22,t=11.365),SGRQ (54.80± 18.12 vs.34.06 ± 12.10,t =6.839) and FEV1％ pred (46.52 ± 22.55 vs.58.22 ± 24.62,t=-2.611),FVC％ pred (60.24± 18.22 vs.70.10±24.20,t =-2.547),FEV1/FVC (62.54± 19.02vs.73.12 ±18.42,t=-3.025),DLCO (62.24 ±22.40 vs.74.52 ±26.26,t=-2.627),episodes of exacerbations (Z =10.213) and hospitalizations during 1-year follow-up [21 (46.67 ％) vs.14 (18.18％),x2 =1 1.260] in patients with cystic bronchiectasis were significantly more severe than those in patients with non-cystic bronchiectasis (all P ＜ 0.05).mMRC dyspnea scale (2.38 ± 1.45 vs.1.92 ± 1.14,t =2.175),LCQ (12.82 ±2.12 vs.16.20 ±3.96,t =-6.140),SGRQ (54.22±21.50 vs.41.20 ± 14.60,t =3.521) and FEV1 ％ pred (54.20 ± 21.60 vs.66.45 ± 28.24,t =-2.668),FVC％ pred (63.10 ±24.32 vs.73.46 ±25.30,t =-2.177),FEV1/FVC (62.22 ±20.80 vs.72.14 ±24.36,t =-2.243),DLCO (58.52 ± 20.42 vs.69.22 ± 25.60,t =-2.344),episodes of exacerbation (Z =19.352) and hospitalization during 1-year follow-up [19 (45.24％) vs.16 (20.00％),x2 =8.575] in patients with bacterial colonization bronchiectasis were significantly more severe than those in patients with non-bacterial colonization bronchiectasis (all P ＜ 0.05).However,there was no significant difference in mortality during 1-year follow-up (all P ＞ 0.05) among patients with different types of bronchiectasis.Conclusion Patients with cystic,bacterial colonization and expectoration types of bronchiectasis seem to have more severe symptoms,more episodes of exacerbations and hospitalizations than those of non-cystic,non-bacteria colonization and dry types of bronchiectasis.

This study aimed to investigate the effect of Patched-1 (PTC1) and PTC2 silencing in a rat model, on Hedgehog (Hh) pathway-mediated recovery from spinal cord injury (SCI). An analytical emphasis on the relationship between the sonic hedgehog (Shh) pathway and nerve regeneration was explored. A total of 126 rats were divided into normal, sham, SCI, negative control (NC), PTC1-RNAi, PTC2-RNAi and PTC1/PTC2-RNAi groups. The Basso, Beattie and Bresnahan (BBB) scale was employed to assess hind limb motor function. Quantitative real-time polymerase chain reaction and western blotting were performed to examine the mRNA and protein levels of PTC1, PTC2, Shh, glioma-associated oncogene homolog 1 (Gli-1), Smo and Nestin. Tissue morphology was analyzed using immunohistochemistry, and immunofluorescent staining was conducted to detect neurofilament protein 200 (NF-200) and glial fibrillary acidic protein (GFAP). The PTC1/PTC2-RNAi group displayed higher BBB scores than the SCI and NC groups. Shh, Gli-1, Smo and Nestin expression levels were elevated in the PTC1/PTC2-RNAi group. PTC1 and PTC2 mRNA and protein expression was lower in the PTC1/PTC2-RNAi group than in the normal, sham and SCI groups. Among the seven groups, the PTC1/PTC2-RNAi group had the largest positive area of NF-200 staining, whereas the SCI group exhibited a larger GFAP-positive area than both the normal and the sham groups. The Shh pathway may provide new insights into therapeutic indications and regenerative recovery tools for the treatment of SCI. Activation of the Hh signaling pathway by silencing PTC1 and PTC2 may reduce inflammation and may ultimately promote SCI recovery.