Nitrogen oxides(NOx=NO+NO2)are important precursors of ozone(O3),and NOx and its oxides together constitute reactive nitrogen oxides(NOy)in the atmosphere.A comprehensive understanding of the total NOy level in the atmosphere is of great significance for a deeper understanding of the atmospheric nitrogen cycle and oxidation,as well as for formulating strategies for air pollution prevention and control.In this work,a thermal decomposition-broadband cavity enhanced absorption spectroscopy(TD-BBCEAS)technique for online measurement of total NOy in the atmosphere was developed.With this method,the NOy was efficiently converted into NO2,and the total NOy concentration in the atmosphere was indirectly obtained by measuring NO2.Focusing on the key factors affecting the measurement of total NOy,the influence of NO titration efficiency and other NOy component TD efficiency on measurement accuracy was emphasized.By changing the oxygen(O2)flow rate through the mercury lamp to alter the O3 concentration for titrating NO,the conversion efficiency of NO was evaluated.At O2 flow rate of 6 mL/min,the conversion efficiency of NO was greater than 99%.TD efficiency testing and analysis on NO2,peroxyacetyl nitrate(PAN),nitric acid(HNO3),and nitrous acid(HONO),which account for a large proportion of atmospheric NOy components,was carried out using 680℃as the optimal TD temperature for efficient conversion of NOy.With NO and HONO sample gases as typical verification gases,the conversion efficiency of NOy and the accuracy of NOy measurement by TD-BBCEAS system were verified by switching the on and off modes of mercury lamp and TD device.At integration time of 60 s,the detection limit of the system for NOy was 2.83×1010 molecules/cm3(60 s,2σ).A comparative measurement of actual atmospheric NOy was conducted between the TD-BBCEAS system and the NOy analyzer.The observation results showed a correlation coefficient(R2)of 0.98 and a slope of 0.93,further verifying the feasibility and accuracy of applying the TD-BBCEAS system to measurement of total NOy.

OBJECTIVE: To explore the neuroprotective effects of Xuefu Zhuyu Decoction (XFZYD) based on in vivo and metabolomics experiments. METHODS: Traumatic brain injury (TBI) was induced via a controlled cortical impact (CCI) method. Thirty rats were randomly divided into 3 groups (10 for each): sham, CCI and XFZYD groups (9 g/kg). The administration was performed by intragastric administration for 3 days. Neurological functions tests, histology staining, coagulation and haemorheology assays, and Western blot were examined. Untargeted metabolomics was employed to identify metabolites. The key metabolite was validated by enzyme-linked immunosorbent assay and immunofluorescence. RESULTS: XFZYD significantly alleviated neurological dysfunction in CCI model rats (P<0.01) but had no impact on coagulation function. As evidenced by Evans blue and IgG staining, XFZYD effectively prevented blood-brain barrier (BBB) disruption (P<0.05, P<0.01). Moreover, XFZYD not only increased the expression of collagen IV, occludin and zona occludens 1 but also decreased matrix metalloproteinase-9 (MMP-9) and cyclooxygenase-2 (COX-2), which protected BBB integrity (all P<0.05). Nine potential metabolites were identified, and all of them were reversed by XFZYD. Adenosine was the most significantly altered metabolite related to BBB repair. XFZYD significantly reduced the level of equilibrative nucleoside transporter 2 (ENT2) and increased adenosine (P<0.01), which may improve BBB integrity. CONCLUSIONS XFZYD ameliorates BBB disruption after TBI by decreasing the levels of MMP-9 and COX-2. Through further exploration via metabolomics, we found that XFZYD may exert a protective effect on BBB by regulating adenosine metabolism via ENT2.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Blood-Brain Barrier/metabolism* ; Brain Injuries, Traumatic/metabolism* ; Adenosine/metabolism* ; Male ; Rats, Sprague-Dawley ; Rats

INTRODUCTION: During the coronavirus disease 2019 (COVID-19) pandemic, contact tracers were under immense pressure to deliver effective and timely contact tracing, raising concerns of higher susceptibility to burnout. Our study aimed to determine burnout prevalence among hospital-based contact tracers and associated risk factors, so that interventions to reduce burnout risk could be formulated. METHODS: One hundred and ninety-six active contact tracers across three hospitals within a healthcare cluster were invited to complete an anonymous online survey. To identify burntout, data such as demographics, work-related variables and contact tracing-related variables were collected using the Copenhagen Burnout Inventory. Associated factors were identified using multivariate statistics. Open-ended questions were included to understand the challenges and potential improvements through qualitative analysis. RESULTS: A total of 126 participants completed the survey, giving a completion rate of 64%, and almost half of these participants (42.9%) reported burnout. Protective factors included being on work-from-home arrangements (adjusted odds ratio [OR] 0.22, 95% confidence interval [CI] 0.08-0.56), perception of being well supported by their institution (adjusted OR 0.25, 95% CI 0.08-0.80) and being married (adjusted OR 0.28, 95% CI 0.12-0.64). Risk factors included having an administrative role pre-COVID-19 (adjusted OR 3.62, 95% CI 1.33-9.83). Work-related burnout was related to being activated for more than 1 day in the preceding week (unadjusted OR 3.25, 95% CI 1.33-7.94) and multiple activations in a day (unadjusted OR 3.54, 95% CI 1.44-4.41). Biggest challenges identified by participants were language barrier (62.7%), followed by workflow-related issues (42.1%). CONCLUSION Our study demonstrated burnout and other challenges faced by a team of mostly hospital-based administrative staff redeployed on a part-time basis to ensure timely contact tracing. To mitigate burnout, we recommend choosing staff on work-from-home arrangements and ensuring adequate manpower and rostering arrangements.
Humans ; COVID-19/epidemiology* ; Burnout, Professional/epidemiology* ; Singapore/epidemiology* ; Female ; Male ; Cross-Sectional Studies ; Adult ; Middle Aged ; Risk Factors ; Surveys and Questionnaires ; Contact Tracing/methods* ; SARS-CoV-2 ; Prevalence ; Pandemics

Objective To explore the risk factors for noncontiguous spinal fractures(NSFs)in the elderly.Methods The clinical data of 614 elderly patients with spinal fracture from January 2013 to December 2019 were analyzed retrospectively.Patients were divided into the NSFs group and the Non-NSFs group according to whether NSFs occurred or not.Univariate analysis and multivariate Logistic regression analysis were used to screen the risk factors of NSFs.Results Univariate analysis showed that female(P=0.003),high-energy violent injury(P=0.032),osteoporosis(P=0.004),fracture in spring(P=0.020),and previous spinal fracture history(P<0.001)were associated with the occurrence of NSFs.Multivariate Logistic regression analysis showed that fracture in spring(P=0.024),previous spinal fracture history(P<0.001)and high-energy violent injury(P=0.038)were the independent risk factors for the occurrence of NSFs in the elderly.Conclusion High-energy violent injury,fracture in spring and previous spinal fracture history are the independent risk factors for the occurrence of NSFs in the elderly.Therefore,elderly patients with the above risk factors should be examined more carefully and comprehensively to avoid missed diagnosis and delayed diagnosis.In order to reduce the incidence of this disease,corresponding measures should be taken according to the preventable risk factors.

Objective To analyze the risk factors for increased drainage volume after open transforaminal lumbar interbody fusion(TLIF),and to establish a predictive model and then validate it.Methods The clinical data of 680 patients who underwent open TLIF at the General Hospital of Northern Theater Command from January 2016 to December 2019 were collected and the patients were randomly divided into the training group(n=476)and the validation group(n=204).Taking the predictive factors screened out by LASSO regression analysis as independent variables,a multivariate Logistic regression predictive model was constructed.The model was internally validated through the receiver operating characteristic(ROC)curve,Hosmer-Lemeshow goodness-of-fit test,and calibration curve,and its clinical utility was assessed via decision curve analysis(DCA).Results LASSO regression analysis screened out four predictive variables:age,number of surgical segments,operative duration,and intraoperative blood loss.The multivariate Logistic regression predictive model demonstrated that age≥60 years,number of surgical segments≥4,operative duration≥2 hours,and intraoperative blood loss≥200 mL were independent influencing factors for the increased postoperative drainage volume in patients undergoing TLIF(P<0.05).ROC curve analysis revealed an area under the curve(AUC)of 0.816(95%CI:0.798 to 0.867)in the training group and 0.783(95%CI:0.685 to 0.823)in the validation group,indicating that the predictive model had good discriminatory ability.Additionally,the Hosmer-Lemeshow goodness-of-fit test and calibration curve indicated that the predictive model had a good degree of fit,and the predicted probability was basically consistent with the actual probability,demonstrating a good calibration.The DCA results confirmed that this predictive model could be applied in clinical practice.Conclusion The risk factors for increased drainage volume after open TLIF include age,number of surgical segments,operative duration,and intraoperative blood loss.The predictive model established based on these factors demonstrates good performance,and it can be applied in clinical guidance for the selection of drainage tube removal time after TLIF.

AIM To prepare fisetin-loaded nanostructured lipid carriers,and to evaluate their in vivo pharmacokinetics.METHODS Ethanol injection method was applied to preparing the nanostructured lipid carriers.With monostearin-phospholipid ratio,monostearin-triacetin ratio and D-α-tocopheryl polyethylene glycol 1000 succinate(TPGS)concentration as influencing factors,encapsulation efficiency as an evaluation index,the formulation was optimized by Box-Behnken response surface method.The crystal form was analyzed by X-ray powder diffraction,after which the morphology was observed by transmission electron microscopy,infrared spectroscopy analysis was performed,the drug relaese was investigated by dialysis bag method,and the stability was determined.Eighteen rats were randomly assigned into 3 groups and given intragastric administration of the 0.5％CMC-Na suspensions of fisetin and its phospholipid complex,nanostructured lipid carriers(150 mg/kg),respectively,after which blood collection was made at0.25,0.5,1,1.5,2,3,4,6,8,12 h,UPLC-MS/MS was adopted in the plasma concentration determination of fisetin,and main pharmacokinetic parameters were calculated.RESULTS The optimal formulation was determined to be 1.56∶1 for monostearin-phospholipid ratio,3.05∶1 for monostearin-triacetin ratio,and 0.2 mg/mL for TPGS concentration.The nearly round fisetin-loaded nanostructured lipid carriers demonstrated the average encapsulation efficiency,drug loading,particle size and Zeta potential of(86.14±1.28)％,(8.96±0.26)％,(212.35±9.04)nm and-(31.13±1.16)mV,respectively.Raw medicine existed in the nanostructured lipid carriers in an amorphous state,preparation process did not affect the hydrogen bonding between raw medicine and phospholipids.The nanostructured lipid carriers displayed the accumulative release rate of 46.12％within 3 h in simulated gastric juice,and that of about 50％within 18 h in simulated intestinal fluid,whose freeze-dried powder exhibited good stability after being placed for 6 months.Compared with raw medicine and phospholipids complex,the nanostructured lipid carriers displayed prolonged tmax,t1/2(P＜0.01)and increased Cmax,AUC0-t,AUC0-∞(P＜0.01),whose relative bioavailability was enhanced to 7.07 times.CONCLUSION Nanostructured lipid carriers can improve the oral bioavailability of fisetin.

Objective To analyze the risk factors for increased drainage volume after open transforaminal lumbar interbody fusion(TLIF),and to establish a predictive model and then validate it.Methods The clinical data of 680 patients who underwent open TLIF at the General Hospital of Northern Theater Command from January 2016 to December 2019 were collected and the patients were randomly divided into the training group(n=476)and the validation group(n=204).Taking the predictive factors screened out by LASSO regression analysis as independent variables,a multivariate Logistic regression predictive model was constructed.The model was internally validated through the receiver operating characteristic(ROC)curve,Hosmer-Lemeshow goodness-of-fit test,and calibration curve,and its clinical utility was assessed via decision curve analysis(DCA).Results LASSO regression analysis screened out four predictive variables:age,number of surgical segments,operative duration,and intraoperative blood loss.The multivariate Logistic regression predictive model demonstrated that age≥60 years,number of surgical segments≥4,operative duration≥2 hours,and intraoperative blood loss≥200 mL were independent influencing factors for the increased postoperative drainage volume in patients undergoing TLIF(P<0.05).ROC curve analysis revealed an area under the curve(AUC)of 0.816(95%CI:0.798 to 0.867)in the training group and 0.783(95%CI:0.685 to 0.823)in the validation group,indicating that the predictive model had good discriminatory ability.Additionally,the Hosmer-Lemeshow goodness-of-fit test and calibration curve indicated that the predictive model had a good degree of fit,and the predicted probability was basically consistent with the actual probability,demonstrating a good calibration.The DCA results confirmed that this predictive model could be applied in clinical practice.Conclusion The risk factors for increased drainage volume after open TLIF include age,number of surgical segments,operative duration,and intraoperative blood loss.The predictive model established based on these factors demonstrates good performance,and it can be applied in clinical guidance for the selection of drainage tube removal time after TLIF.

AIM To prepare fisetin-loaded nanostructured lipid carriers,and to evaluate their in vivo pharmacokinetics.METHODS Ethanol injection method was applied to preparing the nanostructured lipid carriers.With monostearin-phospholipid ratio,monostearin-triacetin ratio and D-α-tocopheryl polyethylene glycol 1000 succinate(TPGS)concentration as influencing factors,encapsulation efficiency as an evaluation index,the formulation was optimized by Box-Behnken response surface method.The crystal form was analyzed by X-ray powder diffraction,after which the morphology was observed by transmission electron microscopy,infrared spectroscopy analysis was performed,the drug relaese was investigated by dialysis bag method,and the stability was determined.Eighteen rats were randomly assigned into 3 groups and given intragastric administration of the 0.5％CMC-Na suspensions of fisetin and its phospholipid complex,nanostructured lipid carriers(150 mg/kg),respectively,after which blood collection was made at0.25,0.5,1,1.5,2,3,4,6,8,12 h,UPLC-MS/MS was adopted in the plasma concentration determination of fisetin,and main pharmacokinetic parameters were calculated.RESULTS The optimal formulation was determined to be 1.56∶1 for monostearin-phospholipid ratio,3.05∶1 for monostearin-triacetin ratio,and 0.2 mg/mL for TPGS concentration.The nearly round fisetin-loaded nanostructured lipid carriers demonstrated the average encapsulation efficiency,drug loading,particle size and Zeta potential of(86.14±1.28)％,(8.96±0.26)％,(212.35±9.04)nm and-(31.13±1.16)mV,respectively.Raw medicine existed in the nanostructured lipid carriers in an amorphous state,preparation process did not affect the hydrogen bonding between raw medicine and phospholipids.The nanostructured lipid carriers displayed the accumulative release rate of 46.12％within 3 h in simulated gastric juice,and that of about 50％within 18 h in simulated intestinal fluid,whose freeze-dried powder exhibited good stability after being placed for 6 months.Compared with raw medicine and phospholipids complex,the nanostructured lipid carriers displayed prolonged tmax,t1/2(P＜0.01)and increased Cmax,AUC0-t,AUC0-∞(P＜0.01),whose relative bioavailability was enhanced to 7.07 times.CONCLUSION Nanostructured lipid carriers can improve the oral bioavailability of fisetin.

Objective To explore the risk factors for noncontiguous spinal fractures(NSFs)in the elderly.Methods The clinical data of 614 elderly patients with spinal fracture from January 2013 to December 2019 were analyzed retrospectively.Patients were divided into the NSFs group and the Non-NSFs group according to whether NSFs occurred or not.Univariate analysis and multivariate Logistic regression analysis were used to screen the risk factors of NSFs.Results Univariate analysis showed that female(P=0.003),high-energy violent injury(P=0.032),osteoporosis(P=0.004),fracture in spring(P=0.020),and previous spinal fracture history(P<0.001)were associated with the occurrence of NSFs.Multivariate Logistic regression analysis showed that fracture in spring(P=0.024),previous spinal fracture history(P<0.001)and high-energy violent injury(P=0.038)were the independent risk factors for the occurrence of NSFs in the elderly.Conclusion High-energy violent injury,fracture in spring and previous spinal fracture history are the independent risk factors for the occurrence of NSFs in the elderly.Therefore,elderly patients with the above risk factors should be examined more carefully and comprehensively to avoid missed diagnosis and delayed diagnosis.In order to reduce the incidence of this disease,corresponding measures should be taken according to the preventable risk factors.

Objective:The aim of this study is to investigate the independent risk factors of benign prostatic hyperplasia(BPH)complicated with bladder stones,and construct a nomogram prediction model for clinical progression of bladder stones in pa-tients with BPH.Methods:The clinical data of 368 BPH patients who underwent transurethral resection of the prostate in the Second Affiliated Hospital of Zhengzhou University from January 2018 to January 2021 were retrospectively analyzed.Patients with BPH were divided into group 1(with bladder stones,n=94)and group 2(without bladder stones,n=274).Univariate and multivariate logistic regression analyses were performed to determine the independent risk factors of bladder stones in patients with BPH.A nomogram mod-el was developed,and the areas under the ROC curve and calibration curve were calculated to assess the accuracy of clinical applica-tion.Results:Logistic analysis showed that age(HR:1.075,95％CI:1.032 to 1.120),hypertension(HR:2.801,95％CI:1.520 to 5.161),blood uric acid(HR:1.006,95％CI:1.002 to 1.010),intravesical prostatic protrusion(HR:1.189,95％CI1.119 to 1.264),prostatic urethral angel(HR:1.127,95％CI:1.078to 1.178)were independent risk factors for bladder stones in patients with BPH.The discrimination of the nomogram model based on independent risk factors to predict the occurrence of bladder stones in pa-tients with BPH was 0.874.Conclusion:The nomogram model can predict the risk of bladder stones in BPH patients with good dif-ferentiation and calibration,which is a good guide for clinical work on BPH patients with high risk of bladder stones.