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

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

OBJECTIVETo develop and test a scoring system to predict the risks of postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy(PD).

METHODSClinic data and postoperative complications of the 445 consecutive patients who underwent a PD procedure between January 2008 and April 2015 in Peking University First Hospital were retrospectively collected and analyzed.The patients were randomly selected to modelling and validation sets at a ratio of 3∶1, respectively.The patient data were subjected to univariate and multivariate analysis in the modelling set of patients.A score predictive of POPF was designed and tested in the validation set.

RESULTSPOPF occurred in 88 of 334 patients(26.4%) in the modelling set.The multivariate analysis showed that body mass index (BMI, P<0.01) and pancreatic duct width(P=0.001) are associated with POPF independently.A risk score to predict POPF was constructed based on these factors and successfully tested.The area under the receiver operating characteristic curve were 0.829(95% CI: 0.777-0.881) on the modelling set and 0.885(95% CI: 0.825-0.945) on the validation set, respectively.

CONCLUSIONSBMI and pancreatic duct width were associated with POPF after PD. The preoperative assessment of a patient's risk for POPF is feasible.The present risk score is a valid tool to predict POPF in patients undergoing PD, to make the selection on anastomosis types, and to take precautions against POPF.

Anastomosis, Surgical ; Body Mass Index ; Humans ; Intestines ; surgery ; Multivariate Analysis ; Pancreas ; pathology ; surgery ; Pancreatic Ducts ; pathology ; Pancreatic Fistula ; pathology ; Pancreaticoduodenectomy ; adverse effects ; Postoperative Complications ; Postoperative Period ; ROC Curve ; Retrospective Studies ; Risk Factors

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 analyze the factors affecting the prognosis of patients with pulmonary sarcomatoid carcinoma (PSC) and construct a nomogram prediction model for the prognosis of PSC patients. Methods Based on the SEER database, 1671 patients diagnosed as PSC from 1988 to 2015 were collected and divided into modeling group and validation group according to the ratio of 7:3. Univariate and multivariate Cox regression analysis were performed in the modeling group to explore independent risk factors affecting the prognosis and construct a nomogram survival prediction model. The consistency index and calibration curve were used for verification in the modeling group and the test module respectively. Results Age, gender, histological type, TNM stage, tumor diameter > 50mm, surgery, radiotherapy and chemotherapy were independent factors that affected the prognosis of PSC patients. The nomogram prediction model was constructed and verified based on independent factors. The C indexes of the modeling group and the test model were 0.790 (95%CI: 0.776-0.804) and 0.781 (95%CI: 0.759-0.803), respectively. The calibration curves of the modeling group and the test model indicated that the predicted survival rate was basically the same as the actual survival rate. Conclusion The nomogram prediction model constructed based on the results of multivariate analysis can predict the prognosis of PSC patients, and has high accuracy and consistency.

Objective:To compare the clinical outcomes of polyetheretherketone (PEEK) and titanium mesh as repair materials in the cranioplasty for cranial defect patients, and to screen the independent factors for postoperative complications of cranioplasty.Methods:A total of 95 patients with cranial defects admitted to our hospital from June 2012 to June 2019 were selected for this study. According to the different repair materials used in cranioplasty, these patients were divided into PEEK group ( n=36) and titanium mesh group ( n=59). General data (hospitalization cost, hospital stay, et al), postoperative complications (intracranial hemorrhage, subcutaneous effusion, infection, seizures, and implant exposure), postoperative plastic satisfaction, and improvement of postoperative neurological function (differences of Glasgow outcome scale [GOS] scores and Mini-mental State Examination [MMSE] scores before and 6 months after surgery) were compared between the 2 groups. Univariate and multivariate Logistic regression analyses were used to screen the independent factors for postoperative complications of cranioplasty. Results:The patients in the PEEK group had significantly higher hospitalization cost but significantly shortened length of hospital stay as compared with those in the titanium mesh group ( P<0.05). The overall incidence of complications in PEEK group was significantly lower than that in titanium mesh group ( P<0.05); the incidence of subcutaneous effusion in PEEK group was significantly lower than that in titanium mesh group ( P<0.05). The PEEK group had significantly higher proportion of patients with good satisfaction in postoperative plasticity, and significantly higher proportions of patients having increased GOS and MMSE scores as compared with the titanium mesh group ( P<0.05). Multivariate Logistic regression analysis showed that repair material was an independent factor for postoperative complications of cranioplasty ( OR=4.550, P=0.019, 95%CI: 1.281-16.161). Conclusion:As compared with titanium mesh, PEEK costs more, but its clinical application effect is better, especially in reducing postoperative complications; selection of appropriate repair materials can be used as one of the methods to reduce postoperative complications.

Objective: To develop the monoclonal antibody (mAb) against neuraminidase of H7N9 subtype influenza A virus and identify its biological function. Methods: Female 8 week-old BALB/c mice were immunized and the splenocytes of the mice were fused with Sp2/0 myeloma cells. Indirect ELISA was used to screen hybridoma and the positive clones were subject to be subcloned. Positive clones were identified and the monoclonal antibodies(mAbs) were obtained by purifying the ascetic fluid of mice injected with the hybridoma. The NA-binding as well as neuraminidase-inhibition activity of these mAbs were determined. Results: Three mAbs against neuraminidase of H7N9 subtype influenza A virus, 1G8, 3C4 and 4E8, were obtained. They demonstrated different epitop-recognizing. 3C4 and 4E8 exhibited neuraminidase inhibitory activity, with a IC₅₀ of 1.45 μg/ml and 8.65 μg/ml, respectively. Conclusions The results suggested that mAbs specific to neuraminidase of H7N9 subtype influenza A virus were developed, providing an useful tool in control and preventing the novel H7N9 influenza A virus.

Objective To explore the importance of head fixation in chest wall field combined with supraclavicular field radiotherapy for breast cancer by comparing the displacement error and dosimetric differences caused by multi-functional body board and breast bracket.Methods Thirty patients with breast cancer were randomly divided into groups A and B.In group A,patients were fixed with multi-functional body board and head thermoplastic film.In group B,patients were fixed with traditional breast brackets.Each patient received CBCT scan before and after radiotherapy.Both setup errors and intra-fractional displacements in the x-,y-and z-axis,V100 and V95 were calculated.Statistical analyses were performed using the independent sample t-test.Results The displacement errors in groups A and B before and after radiotherapy were (1.24± 0.42),(1.71± 0.61) and (2.25± 1.04) mm vs.(3.67± 2.05),(3.78± 1.74),(4.65±2.66) mm in the x-,y-and z-axis,respectively (P=0.033,0.027,0.020).The intra-fractional displacements in groups A and B were (1.10±0.66),(1.13±0.59),(1.11 ±0.62) mm vs.(2.48±0.88),(2.21 ±0.98),(3.53±2.01) mm in the x-,y-and z-axis,respectively (P=0.030,0.021,0.013).The V100 in groups A and B were (94.27± 3.20) ％ and (99.08± 0.60) ％ (P =0.065),and (89.48± 4.70) ％ and (96.53± 2.50) ％ for V95 (P =0.002),respectively.Conclusion The risk of displacement error is significantly reduced using multi-functional body board,which enhances the accuracy of radiation dose in chest wall and supraclavicular fields of breast cancer patients.

Objective: To develop a model incorporating radiomic features and clinical factors to accurately predict acute ischemic stroke (AIS) outcomes. Materials and Methods: Data from 522 AIS patients (382 male [73.2%]; mean age ± standard deviation, 58.9 ± 11.5 years) were randomly divided into the training (n = 311) and validation cohorts (n = 211). According to the modified Rankin Scale (mRS) at 6 months after hospital discharge, prognosis was dichotomized into good (mRS ≤ 2) and poor (mRS > 2); 1310 radiomics features were extracted from diffusion-weighted imaging and apparent diffusion coefficient maps. The minimum redundancy maximum relevance algorithm and the least absolute shrinkage and selection operator logistic regression method were implemented to select the features and establish a radiomics model. Univariable and multivariable logistic regression analyses were performed to identify the clinical factors and construct a clinical model. Ultimately, a multivariable logistic regression analysis incorporating independent clinical factors and radiomics score was implemented to establish the final combined prediction model using a backward step-down selection procedure, and a clinical-radiomics nomogram was developed. The models were evaluated using calibration, receiver operating characteristic (ROC), and decision curve analyses. Results: Age, sex, stroke history, diabetes, baseline mRS, baseline National Institutes of Health Stroke Scale score, and radiomics score were independent predictors of AIS outcomes. The area under the ROC curve of the clinical-radiomics model was 0.868 (95% confidence interval, 0.825–0.910) in the training cohort and 0.890 (0.844–0.936) in the validation cohort, which was significantly larger than that of the clinical or radiomics models. The clinical radiomics nomogram was well calibrated (p > 0.05). The decision curve analysis indicated its clinical usefulness. Conclusion The clinical-radiomics model outperformed individual clinical or radiomics models and achieved satisfactory performance in predicting AIS outcomes.

OBJECTIVE To explore the effect mechanism of ethanol extract from Atractylodes macrocephala （EEAM） on microglial phagocytosis and degradation of amyloid β （Aβ） based on peroxisome proliferator-activated receptor γ （PPAR- γ） signaling pathway. METHODS Taking neuromicroglial cell BV2 as subjects， confocal microscopy was used to observe the effects of EEAM （0.3， 0.4， 0.5 mg/mL， similarly hereinafter） on phagocytosis and degradation of Aβ in microglia. Human embryonic kidney cell HEK293 was used to investigate the effects of EEAM on luciferase transcriptional activity of PPAR-γ. The effect of EEAM on nuclear translocation of PPAR-γ was investigated by immunofluorescence. Alzheimer’s disease BV2 cell model was induced by Aβ1-42， and quantitative polymerase chain reaction was used to investigate the effects of EEAM on mRNA expressions of PPAR-γ downstream target genes （Lxra， Lxrb， Abca1， Abcg1， Cd36， Sra and Apoe）. RESULTS The results of Aβ uptake experiment showed that after the intervention of medium and high doses of EEAM， fluorescence intensity of Aβ in BV2 cells increased significantly （P＜0.05）. The degradation experiment of Aβ showed that after the intervention of medium and high doses of EEAM， fluorescence intensity of Aβ in BV2 cells decreased significantly （P＜0.05）. After the intervention of different doses of EEAM， luciferase transcriptional activity of PPAR-γ in HEK293 cells increased significantly （P＜0.05）； fluorescence intensity of PPAR-γ in BV2 cells and nuclei （except for low-dose group） increased significantly （P＜0.05）. mRNA expressions of Lxra， Lxrb， Abca1， Abcg1， Cd36， Sra and Apoe in BV2 cells were increased significantly （P＜0.05）. CONCLUSIONS EEAM can promote the uptake and degradation of Aβ in microglia by activating PPAR-γ signaling pathway， thus improving Alzheimer’s disease.