Tricarboxylic acid cycle metabolites: new players in macrophage.

Metabolic remodeling is a key feature of macrophage activation and polarization. Recent studies have demonstrated the role of tricarboxylic acid (TCA) cycle metabolites in the innate immune system. In the current review, we summarize recent advances in the metabolic reprogramming of the TCA cycle during macrophage activation and polarization and address the effects of these metabolites in modulating macrophage function. Deciphering the crosstalk between the TCA cycle and the immune response might provide novel potential targets for the intervention of immune reactions and favor the development of new strategies for the treatment of infection, inflammation, and cancer.

Construction of a postoperative infection outbreak investigation form: A tool for early detection and control measures.

BACKGROUND: To develop an investigation form for postoperative infection outbreak (PIO), and to identify sources of the outbreak in the early stage. METHODS: After an exhaustive literature review, we used the Delphi method to determine the indicators and relative risk scores of the assessment tools through 2 rounds of specialist consultation and overall consideration of the opinions and suggestions of 20 specialists. RESULTS: A total of 203 studies of PIO were eligible for inclusion. The mean authority coefficient (Cr) was 0.87. Kendall's W coefficient of the specialist consultation was 0.704 after 2 rounds of consultation (P < .005), suggesting that the specialists had similar opinions. Based on 4 primary items and 19 secondary items of the source of PIO, and tripartite distribution characteristics of infected patients, we constructed the PIO investigation form. CONCLUSIONS: The PIO investigation form can be used in the investigation of the early-stage cluster of cases, it's a prerequisite for taking effective control measures, avoiding PIO occurrence. However, the effect of the investigation form needs to be further evaluated.

Development and evaluation of an ultra-wide bandwidth based electronic hand hygiene monitoring system.

BACKGROUND: A large variety of electronic hand hygiene monitoring systems (EHHMS) are being developed and applied in health care settings. Monitoring hand hygiene (HH) opportunity at bed-level has been the key technical challenge. Accuracy evaluation needs more attention as the prerequisite upon widespread acceptance and adoption. METHODS: For the first time, we explored, debugged and upgraded an EHHMS based on ultra-wide bandwidth (UWB) which can obtain HH opportunities at bed-level. The real-time positioning and electronic fence of UWB technology was applied for EHHMS. The accuracy of EHHMS was compared with the simultaneous manual direct observations in real-world clinical setting. Sensitivity and specificity were calculated for EHHMS capturing HH action and opportunity. RESULTS: Two generations of EHHMS were constructed. For the first generation, the system properly recorded 84% and 78% of the pre-identified HH actions and opportunities performed by experimenters. For the second generation, sensitivity and specificity of the system capturing HH action were 89% (84.83-92.36) and 100% (98.26-100.00), respectively. For capturing HH opportunity, the system showed the sensitivity and specificity of 86.52% (82.52-89.89) and 88.10% (84.14-91.36)), respectively. CONCLUSION: The EHHMS based on UWB could accurately identify HH action and opportunity with equivalent accuracy compared with simultaneous direct observation.

Co-Exposure to Multiple Pollutants and Its Cardiovascular Effects in a Subway System - Beijing Municipality, China, 2017.

WHAT IS ALREADY KNOWN ON THIS TOPIC?: With rapid urbanization, traffic-related air pollution has become a global concern. However, its association with cardiovascular health has not been fully elucidated. WHAT IS ADDED BY THIS REPORT?: This study provided novel evidence of the joint cardiovascular effect of multiple pollutants in subway cabins, further identified two pollutants that played dominant roles, and validated the effectiveness of targeted interventions. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?: The findings were helpful to guide the formulation and development of prevention and control strategies for key traffic-related pollutants that endanger the cardiovascular health of commuters.

Prevention and control strategies for the post-pandemic era: finding a balance between COVID-19 and reviving medical service.

INTRODUCTION: Public life in China is gradually returning to normal with strong measures in coronavirus 2019 (COVID-19) control. Because of the long-term effects of COVID-19, medical institutions had to make timely adjustments to control policies and priorities to balance between COVID-19 prevention and daily medical services. METHODOLOGY: The framework for infection prevention and control in the inpatient department was effectively organized at both hospital and department levels. A series of prevention and control strategies was implemented under this leadership: application of rigorous risk assessment and triage before admission through a query list; classifying patients into three risk levels and providing corresponding medical treatment and emergency handling; establishing new ward visiting criteria for visitors; designing procedures for PPE and stockpile management; executing specialized disinfection and medical waste policies. RESULTS: Till June 2020, the bed occupancy had recovered from 20.0% to 88.1%. In total, 13045 patients were received in our hospital, of which 54 and 127 patients were identified as high-risk and medium-risk, respectively, and 2 patients in the high-risk group were eventually laboratory-confirmed with COVID-19. No hospital-acquired infection of COVID-19 has been observed since the emergency appeared. CONCLUSIONS: The strategies ensured early detection and targeted prevention of COVID-19 following the COVID-19 pandemic, which improved the recovery of medical services after the pandemic.

Chemical constituents and sources of indoor PM2.5 and cardiopulmonary function in patients with chronic obstructive pulmonary disease: Estimation of individual and joint effects.

BACKGROUND: The cardiopulmonary effects of chemical constituents and sources of indoor fine particulate matter (PM2.5) remain unclear. OBJECTIVES: To examine the individual and joint effects of constituents of indoor PM2.5 on cardiopulmonary function of patients with chronic obstructive pulmonary disease (COPD) and the role of identified sources. METHODS: This panel study recruited 43 stable COPD patients from November 2015 to May 2016 in Beijing, China. Daily indoor and outdoor PM2.5 were collected for five consecutive days simultaneously. Twenty-four elements were measured and principal component analysis was used for source appointment. Pulmonary function and blood pressure (BP) were also measured at daily visit. The linear mixed-effect models were used to estimate the effect of each constituent and source. Bayesian kernel machine regression (BKMR) models were used to estimate the overall effect of all measured constituents. RESULTS: The combustion, indoor soil/dust and road dust sources were identified as the main sources of indoor PM2.5 and combustion sources contributed over 40% during the heating season. Most constituents were significantly associated with elevated BP of COPD patients and the joint effects of mixed exposures were also significant especially during the heating season. Most associations of chemical constituents with pulmonary function were negative but not statistically significant during the heating season, as was the joint effect. Few associations were observed during the non-heating season. Further, we observed combustion sources throughout the study period and road dust sources during the heating season were significantly associated with increased BP but not decreased pulmonary function. CONCLUSION: The combustion and road dust sources and their related constituents of indoor PM2.5 could cause adverse effects on cardiovascular function of COPD patients especially during the heating season, but the effect on pulmonary function still needs to be further studied.

Practice and exploration of infection prevention and control measures based on risk management of surgical patients during the epidemic of corona virus disease 2019 (COVID-19).

BACKGROUND: An outbreak of corona virus disease 2019 (COVID-19) in Wuhan, China has spread quickly across the world, the World Health Organization (WHO) has declared this a pandemic. COVID-19 can be transmitted from human to human and cause nosocomial infection that has brought great challenges to infection control in medical institutions. Due to the professional characteristics, the research hospital still received a large number of trauma emergency tasks during the outbreak. It is urgent to establish a graded prevention and control guidance of surgery. METHODS: Review the implementation of surgical grading control measures in this hospital during the epidemic of COVID-19. RESULTS: The surgical prevention measures based on patients with different risks included prescreening and preoperative risk assessment, preparation of operating room, medical staff protection and environmental disinfection measures, etc. From January 20 to March 5, 2020, a total of 4,720 operations had been performed in this hospital, of which 1,565 were emergency operations and 22 for medium-risk and high-risk patients who may have the 2019 severe acute respiratory syndrome coronavirus 2 infection. And there is no medical staff exposed during the implementation of protective measures. CONCLUSIONS: Through the risk assessment of surgical patients and adopting surgical grading control measures, the risk of severe acute respiratory syndrome coronavirus 2 spread during the surgical process can be reduced greatly.

Comparative effectiveness and safety of antiviral agents for patients with COVID-19: Protocol for a systematic review and individual-patient data network meta-analysis.

BACKGROUND: A recent cluster of pneumonia cases in Wuhan, China, has been caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We propose the protocol described below to perform an individual-patient data (IPD) network meta-analysis (NMA) in order to evaluate the efficacies of different antiviral drugs to treat patients with coronavirus disease 2019 (COVID-19). MATERIALS AND METHODS: We will search the Medline, EMBASE, Cochrane Library, SinoMed, CNKI and VIP databases from their inceptions through July 2020. There will be no restrictions on language, publication year, or publication type. Randomized clinical trials (RCTs) and prospective cohort studies with antiviral treatments for COVID-19 will be considered. Two reviewers will independently select studies and collect data. Risk-of-bias assessments will be completed using the Cochrane risk-of-bias scale. Primary outcome will be the COVID-19 recovery rate. We will combine aggregated data from IPD with the NMA in a single model, compare the effects of different antiviral drugs on patient-relevant efficacy, and rank the results to decide which is the most effective. TRIAL REGISTRATION: PROSPERO registration number: CRD42020167038.

Indirect comparison of efficacy between different antibiotic prophylaxis against the intracranial infection after craniotomy.

BACKGROUND: Many studies had shown that prophylactic use of antibiotics could significantly reduce the intracranial infection (ICI) rate of craniotomy. However, there has been no comparison of these antibiotics. METHODS: An electronic database search was performed, from inception to June 102,020. Randomized controlled trials (RCT) using different intravenous antibiotics (IVA) against the ICIs after craniotomy were considered. The primary outcome was the incidence rates of ICIs. An indirect treatment comparison (ITC) was conducted to compare the protective effect among the diverse antibiotic prophylaxis to prevent ICIs after craniotomy. Risk of potential bias was assessed. RESULTS: A total of 3214 patients after craniotomy in 11 studies were included, 159 patients experienced postoperative ICI, including 33 patients in the antibacterial group and 126 in the control group. The calculate results of meta-analysis showed that except fusidic acid, preoperative intravenous injection of cephalosporin, clindamycin, vancomycin, and penicillin can significantly reduce the incidence of ICI after craniotomy, and ITC showed there was no statistically significance difference in the rates of post craniotomy ICI between the various antibiotics. CONCLUSION: The current evidence shows that low-grade antibacterial drugs can be selected to prevent ICI after craniotomy, but this may be due to the limited number of studies per antibiotic. It still needs more high-quality, large sample RCT to confirm. SYSTEMIC REVIEW REGISTRATION: PROSPERO CRD42019133369.

Status and Challenges of Public Health Emergency Management in China Related to COVID-19.

Objective: This study aimed at exploring the current development status and problems of health emergency management in China and provides a reference for improving, constructing, and implementing a public health emergency management system. Methods: Cases of major and severe public health emergencies in China were analyzed along with the relevant health emergency management literature from the last decade. Results: China's health emergency system gradually improved during the study period. Monitoring and early warning systems were significantly strengthened. Material reserves and transfer management systems were constantly improved. However, the operational efficiency of command and decision systems was low, versatile talent accounted for a relatively small proportion, and emergency fund investment was insufficient. Conclusion: Constructing a sound and scientific emergency management mechanism is a lengthy and challenging process. To establish an emergency management mode for public health emergencies that is appropriate for China, it is necessary to solve existing problems and learn from the models and experiences of developed foreign countries.

Comparison of wear resistance of three kinds of glass ceramics and Wieland Zenostar zircona / 吉林大学学报(医学版)

Objective:To explore the differences of wear resistance of three kinds of glass ceramics and Wieland Zenostar zircona (Zenostar) , and to clarify their influencing factors.Methods:Zenostar were made into flat-shaped specimens (zirconia base sample group) and hemisphere-shaped specimens (zirconia pair grinding group) .There kinds of glass ceramics IPS Empress (Empress) , IPS e.max CAD (e.max) , VITA Suprinity (Suprinty) were used as base specimens.Each group was exposed to UMT-2testing machine to simulate the clinical service.The wear depthes of base specimens were detected by laser confocal scanning.Scanning electron microscope (SEM) was used to evaluate the wear surfaces.Results:In zirconia base sample group, there were no significant differences in the maximum wear depthes to Zenostar between the three kinds of glass ceramics (P＞0.05) .In zirconia pair grinding group, the maximum wear depthes ranked as follows:Zenostar group＜e.max group≈Empress group＜Suprinity group;there was no significant difference between e.max group and Empress group (P＞0.05) , but there were significant differences between other groups (P＜0.01) .The SEM results showed that the wearing surface of the Zenostar in zirconia base sample group was relatively smooth;whereas the wearing surface of Empress in zirconia pair grinding group was rougher with alarge area of clebris desquamation surface.Conclusion:The wear resistance of the three kinds of glass ceramics to Zenostar is related to the compositions and the chemical structures of materials.

Comparison of the preventive effect of urethral cleaning versus disinfection for catheter-associated urinary tract infections in adults: A network meta-analysis.

BACKGROUND: Catheter-associated urinary tract infections (CAUTIs) are the main cause of infectious complications in patients with indwelling urinary catheters (IDCs). However, the best cleaning methods for the prevention of CAUTIs have not been evaluated clearly in previous studies. METHODS: An electronic database search was performed, from inception to December 2017. Randomized controlled trials and quasi-experimental trials using different methods of urethral cleaning versus disinfection to prevent CAUTIs were considered. The study selection and data collection were performed independently by two reviewers. The risk of bias assessment was performed using the Cochrane risk of bias scale. The primary outcome was the incidence rates of CAUTIs. A network meta-analysis was conducted to compare the effect among the different methods of urethral cleaning versus disinfection to prevent CAUTIs. RESULTS: Thirty-three studies (6490 patients) with seven different methods of urethral cleaning versus disinfection were eligible for inclusion, and the data were summarized in the network meta-analysis. No evidence of heterogeneity (P>0.05) was observed among the studies. The network meta-analysis showed that there was no difference in the incidence of CAUTIs when comparing the different urethral cleaning methods versus disinfection (P>0.05 for all). However, chlorhexidine ranked first in the results of the Bayesian analysis and is recommended for preventing CAUTIs. CONCLUSIONS: Current evidence suggests that there are no significant differences among different urethral cleaning versus disinfection methods with regard to CAUTI incidence rates.

Short-term effects of particulate matter in metro cabin on heart rate variability in young healthy adults: Impacts of particle size and source.

BACKGROUND: Metro system has become popular in urban areas. However, short-term effects of size-fractionated particulate matter (PM) on cardiac autonomic function in metro system remain unexplored. OBJECTIVES: To explore the contribution of ambient PM to in-cabin PM and investigate the short-term effects of exposure to size-fractionated PM and black carbon (BC) in metro system on cardiac autonomic function in young healthy adults. METHODS: Thirty nine young healthy adults were asked to travel in metro system during 9:00-13:00 on a weekends between March and May 2017. We performed continuous ambulatory electrocardiogram monitoring for each of them, and measured real-time size-fractionated PM, BC, nitrogen dioxide, nitric oxide, carbon dioxide, ozone, noise, temperature and relative humidity in metro cabin. We also collected the data of ambient PM2.5 (aerodynamic diameter < 2.5 µm) concentrations in Beijing. Linear regression model was used to estimate the infiltration factor of ambient PM2.5 to assess the relationship between metro cabin PM and ambient PM. Mixed-effects model was used to estimate the associations between changes in HRV parameters and PM0.5 (aerodynamic diameter < 0.5 µm), PM0.5-2.5 (aerodynamic diameter between 0.5 µm and 2.5 µm), PM2.5-10 (aerodynamic diameter between 2.5 µm and 10 µm), and BC, respectively. RESULTS: We found that size-fractionated PM in metro systems were significantly associated with HRV parameters. Per IQR (interquartile range) increase in PM0.5 (1.6*107/m3) in 1-h moving average concentration was associated with a 13.96% (95% CI: - 18.99%, - 8.61%) decrease in SDNN (standard deviation of normal-to-normal intervals). Similar inverse associations were found between size-fractionated PM exposure and LF (low frequency power), HF (high frequency power), respectively, and smaller particles had greater effects on HRV parameters at shorter lag time. Sex of participants modified the adverse associations between size-fractionated PM and HRV. An IQR of 1-h PM0.5 increasing was associated with a decrease of 6.05% (95% CI: - 22.87%, - 14.44%) in males and a 34.87% (95% CI: - 49.59%, - 15.85%) in females in LF (P for interaction = 0.026). The infiltration factor of ambient PM2.5 was 0.39 (95% CI: 0.33, 0.45). It is estimated that PM2.5 originated from ambient air may account for 20.2% of the PM measured in metro cabin. Per IQR increase in BC (5.5 µg/m3) in 5-min, 1-h, and 2-h moving averages, a primary tracer for ambient PM from combustion source, was associated with decreases of 0.84% (95% CI: - 1.20%, - 0.47%), 2.22% (95% CI: - 3.20%, - 1.22%), and 4.44% (95% CI: - 6.28%, - 2.56%) in SDNN, respectively. CONCLUSIONS: Short-term exposure to PM may disturb metro commuter's cardiac autonomic function, and the potential effects depend on the size of PM and the sex of commuters. Ambient PM from combustion source may have adverse effects on the cardiac autonomic function of passengers in cabin.

The short-term effects of indoor size-fractioned particulate matter and black carbon on cardiac autonomic function in COPD patients.

BACKGROUND: Previous studies have reported adverse health effects of indoor air pollutants especially particulate matter (PM) and black carbon (BC). Patients with chronic obstructive pulmonary disease (COPD) have been shown to be more likely with cardiovascular comorbidities in which cardiac autonomic dysfunction plays an important role. However, there is little evidence for the effect of indoor PM and BC exposures on cardiac autonomic function in COPD patients. OBJECTIVES: To evaluate the association between exposure to indoor size-fractioned PM and BC and changes in HRV and HR in COPD patients. METHODS: Forty-three doctor diagnosed, stable COPD patients were recruited and measured for 24-h HRV and HR. Real-time indoor size-fractioned PM and BC were monitored on the day before and the day of performing health measurements. Mixed-effects models were used to estimate the associations between indoor PM and BC and HRV indices and HR after controlling for potential confounders. RESULTS: Increasing levels of size-fractioned PM and BC were associated with decreased HRV indices and increased HR. An IQR (3.14µg/m3) increase in 8-h BC moving average and an IQR (20.72µg/m3) increase in 5-min PM0.5 moving average concentrations were associated with declines of 7.45% (95% CI: -10.89%, -3.88%) and 16.40% (95% CI: -21.06%, -11.41%) in LF, respectively. The smaller the particles size, the greater effects on HRV indices and HR. Patients' BMI modified the associations between size-fractioned PM and BC and their HRV and HR. For an IQR increase in PM0.5, there was decline in HF of 34.85% (95% CI: -39.08%, -30.33%) in overweight patients, compared to a 2.01% (95% CI: -6.44%, 11.19%) increase in normal-weight patients. CONCLUSIONS: Exposures to indoor PM and BC were associated with altered cardiac autonomic function in COPD patients, and the associations for HRV measures of parasympathetic activity (e.g., HF) were more apparent in overweight patients.

Short-term effects of various ozone metrics on cardiopulmonary function in chronic obstructive pulmonary disease patients: Results from a panel study in Beijing, China.

BACKGROUND: Short-term exposure to ambient air pollution has been associated with lower pulmonary function and higher blood pressure (BP). However, controversy remains regarding the relationship between ambient multiple daily ozone (O3) metrics and cardiopulmonary health outcomes, especially in the developing countries. OBJECTIVES: To investigate and compare the short-term effects of various O3 metrics on pulmonary function, fractional exhaled nitric oxide (FeNO) and BP in a panel study of COPD patients. METHODS: We measured pulmonary function, FeNO and BP repeatedly in a total of 43 patients with COPD for 215 home visits. Daily hourly ambient O3 concentrations were obtained from central-monitoring stations close to subject residences. We calculated various O3 metrics [daily 1-h maximum (O3-1 h max), maximum 8-h average (O3-8 h max) and 24-h average (O3-24 h avg)] based on the hourly data. Daily indoor O3 concentrations were estimated based on estimated indoor/outdoor O3 ratios. Linear mixed-effects models were used to estimate associations of various O3 metrics with cardiopulmonary function variables. RESULTS: An interquartile range (IQR) increase in ambient O3-8 h max (80.5 µg/m3, 5-d) was associated with a 5.9% (95%CI: -11.0%, -0.7%) reduction in forced expiratory volume in 1 s (FEV1) and a 6.2% (95%CI: -10.9%, -1.5%) reduction in peak expiratory flow (PEF). However, there were no significant negative associations between ambient O3-1 h max, O3-24 h avg and FEV1, PEF. An IQR increase in ambient O3-1 h max (85.3 µg/m3, 6-d) was associated with a 6.7 mmHg (95%CI: 0.7, 12.7) increase in systolic BP. The estimated indoor O3 were still significantly associated with reduction of FEV1 and PEF. No significant associations were found between various O3 metrics and FeNO. CONCLUSIONS: Our results provide clues for the adverse cardiopulmonary effects associated with various O3 metrics in COPD patients and highlight that O3-8 h max was more closely associated with respiratory health variables.

Comparison of dentinal microcrack development after canal preparation with three kinds of reciprocating nickel-titaninm instruments in a cadaver model / 吉林大学学报(医学版)

Objective:To observe the development of dentinal microcracks after root canal preparation with there kinds of reciprocating nickel-titaninm instruments using an in situ cadaver model by means of micro-computed tomography (Micro CT),and to provide the reference for their clinical application.Methods:A total of 15 mandible bone specimens having at least the anterior teeth (n=60) with single root were selected and there was no dentina microcrack,then they were randomly divided into 4 groups (n=15) according to the preparation protocol:Wave One,Reciproc,One File and ProTaper Universal groups,and ProTaper Universal was used as control group.The root canals were prepared up to 25 # instruments in Wave One,Reciproc and One File groups and F2 instruments in ProTaper Universal groups.After the preparation procedures,the specimens were scanned by Micro CT again,and the number of dentinal microcracks were investigated and analyzed statistically.Results:Compared with ProTaper Universal group,the incidence rates in Wave One,Reciproc and One File groups were significantly reduced (P＜0.05).There were no statistical differences in the incidence rates of dentinal microcracks between Wave One,Reciproc and One File groups (P＞0.05).Conclusion:Root canal preparation can cause the dentinal microcracks,so it is important to choose the types of instruments.Root canals prepared with Reciproc,Wave One and One File produce less dentinal microcracks,which can decrease the risk of vertical root fracture.

Ambient temperature and cardiovascular biomarkers in a repeated-measure study in healthy adults: A novel biomarker index approach.

BACKGROUND: Associations of ambient temperature with cardiovascular morbidity and mortality have been well documented in numerous epidemiological studies, but the underlying pathways remain unclear. We investigated whether systemic inflammation, coagulation, systemic oxidative stress, antioxidant activity and endothelial function may be the mechanistic pathways associated with ambient temperature. METHODS: Forty study participants underwent repeated blood collections for 12 times in Beijing, China in 2010-2011. Ambient temperature and air pollution data were measured in central monitors close to student residences. We created five indices as the sum of weighted biomarker percentiles to represent the overall levels of 15 cardiovascular biomarkers in five pathways (systemic inflammation: hs-CRP, TNF-α and fibrinogen; coagulation: fibrinogen, PAI-1, tPA, vWF and sP-selectin; systemic oxidative stress: Ox-LDL and sCD36: antioxidant activity: EC-SOD and GPX1; and endothelial function: ET-1, E-selectin, ICAM-1 and VCAM-1). We used generalized mixed-effects models to estimate temperature effects controlling for air pollution and other covariates. RESULTS: There were significant decreasing trends in the adjusted means of biomarker indices over the lowest to the highest quartiles of daily temperatures before blood collection. A 10°C decrease at 2-d average daily temperature were associated with increases of 2.5% [95% confidence interval (CI): 0.7, 4.2], 1.6% (95% CI: 0.1, 3.1), 2.7% (95% CI: 0.5, 4.8), 5.5% (95% CI: 3.8, 7.3) and 2.0% (95% CI: 0.3, 3.8) in the indices for systemic inflammation, coagulation, systemic oxidative stress, antioxidant activity and endothelial function, respectively. In contrast, the associations between ambient temperature and individual biomarkers had substantial variation in magnitude and strength. CONCLUSIONS: The altered cardiovascular biomarker profiles in healthy adults associated with ambient temperature changes may help explain the temperature-related cardiovascular morbidity and mortality. The biomarker index approach may serve as a novel tool to capture ambient temperature effects.

Chemical constituents and sources of ambient particulate air pollution and biomarkers of endothelial function in a panel of healthy adults in Beijing, China.

BACKGROUND: Exposure to ambient air pollution has been associated with endothelial dysfunction as reflected by short-term alterations in circulating biomarkers, but the chemical constituents and pollution sources behind the association has been unclear. METHODS: We investigated the associations between various ambient air pollutants including gases and 31 chemical constituents and seven sources of fine particles (PM2.5) and biomarkers of endothelial function, including endothelin-1 (ET-1), E-selectin, soluble intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), based on 462 repeated measurements in a panel of 40 college students who were followed for three study periods before and after relocating from a suburban area to an urban area in Beijing, China in 2010-2011. Air pollution data were obtained from central air-monitoring stations. Linear mixed-effects models were used to estimate the changes in biomarkers associated with exposures. RESULTS: Total PM2.5 mass showed few appreciable associations with examined biomarkers. However, several PM2.5 constituents and related sources showed significant associations with examined biomarkers. PM2.5 from dust/soil and several crustal and transition metals, including strontium, iron, titanium, cobalt and magnesium, were significantly associated with increases in ET-1 at 1-day average; manganese and potassium were significantly associated with increases in ICAM-1 at 2-day average; and PM2.5 from industry and metal cadmium were significantly associated with decreases in VCAM-1 at 1-day average. In addition, carbon monoxide was significantly associated with increasing ICAM-1 at 1-day and 2-day averages, whereas nitric oxide was significantly associated with decreasing ICAM-1 at 1-day and 3-day averages. CONCLUSIONS: Our results suggest that certain PM2.5 metal constituents were more closely associated with circulating biomarkers of endothelial function than PM2.5, and therefore highlight the research necessity to examine pollution chemical constituents in future studies.

Novel redox species polyaniline derivative-Au/Pt as sensing platform for label-free electrochemical immunoassay of carbohydrate antigen 199.

A novel electrochemical redox-active nanocomposite was synthesized by a one-pot method using N,N'-diphenyl-p-phenylediamine as monomer, and HAuCl4 and K2PtCl4 as co-oxidizing agents. The as-prepared poly(N,N'-diphenyl-p-phenylediamine)-Au/Pt exhibited admirable electrochemical redox activity at 0.15 V, excellent H2O2 electrocatalytic ability and favorable electron transfer ability. Based on these, the evaluation of the composite as sensing substrate for label-free electrochemical immunosensing to the sensitive detection of carbohydrate antigen 199 was described. This technique proved to be a prospective detection tool with a wide liner range from 0.001 U mL(-1) to 40 U mL(-1), and a low detection limit of 2.3 × 10(-4) U mL(-1) (S/N = 3). In addition, this method was used for the analysis of human serum sample, and good agreement was obtained between the values and those of enzyme-linked immunosorbent assay, implying the potential application in clinical research. Importantly, the strategy of the present substrate could be extended to other polymer-based nanocomposites such as polypyrrole derivatives or polythiophene derivatives, and this could be of great significance for the electrochemical immunoassay.