Using machine learning to predict the bleeding risk for patients with cardiac valve replacement treated with warfarin in hospitalized.

BACKGROUND: Distinguishing warfarin-related bleeding risk at the bedside remains challenging. Studies indicate that warfarin therapy should be suspended when international normalized ratio (INR) ≥ 4.5, or it may sharply increase the risk of bleeding. We aim to develop and validate a model to predict the high bleeding risk in valve replacement patients during hospitalization. METHOD: Cardiac valve replacement patients from January 2016 to December 2021 across Nanjing First Hospital were collected. Five different machine-learning (ML) models were used to establish the prediction model. High bleeding risk was an INR ≥4.5. The area under the receiver operating characteristic curve (AUC) was used for evaluating the prediction performance of different models. The SHapley Additive exPlanations (SHAP) was used for interpreting the model. We also compared ML with ATRIA score and ORBIT score. RESULTS: A total of 2376 patients were finally enrolled in this model, 131 (5.5%) of whom experienced the high bleeding risk after anticoagulation therapy of warfarin during hospitalization. The extreme gradient boosting (XGBoost) exhibited the best overall prediction performance (AUC: 0.882, confidence interval [CI] 0.817-0.946, Brier score, 0.158) compared to other prediction models. It also shows superior performance compared with ATRIA score and ORBIT score. The top 5 most influential features in XGBoost model were platelet, thyroid stimulation hormone, body surface area, serum creatinine and white blood cell. CONCLUSION: A model for predicting high bleeding risk in valve replacement patients who treated with warfarin during hospitalization was successfully developed by using machine learning, which may well assist clinicians to identify patients at high risk of bleeding and allow timely adjust therapeutic strategies in evaluating individual patient.

[Characteristics and Cause of PM2.5 During Haze Pollution in Winter 2022 in Zhoukou, China].

The characteristics and main factors of causes of haze in Zhoukou in January 2022 were analyzed. Six air pollutants, water-soluble ions, elements, OC, EC, and other parameters in fine particulate matter were monitored and analyzed using a set of online high-time-resolution instruments in an urban area. The results showed that the secondary inorganic aerosols(SNA), carbonaceous aerosols(CA, including organic carbon OC and inorganic carbon EC), and reconstructed crustal materials(CM, such as Al2O3, SiO2, CaO, and Fe2O3, etc.) were the three main components, accounting for 61.3%, 24.3%, and 9.72% in PM2.5, respectively. The concentrations of SNA, CA, CM, and SOA were increased, accompanied with higher AQI. The sulfur oxidation rate(SOR) and nitrogen oxidation rate(NOR) in January were 0.53 and 0.46, respectively. The growth rates[µg·(m3·h)] of sulfate and nitrate were 0.027(-5.89-9.47, range) and 0.051(-23.1-12.4), respectively. During the haze period, the growth rates of sulfate and nitrate were 0.13 µg·(m3·h)-1and 0.24 µg·(m3·h)-1, which were 4.8 and 4.7 times higher than the average value of January, respectively. Although the sulfur oxidation rate was greater than the nitrogen oxidation rate, the growth rate of nitrate was approximately 1.8 times that of sulfate owing to the difference in the concentration of gaseous precursors and the influence of relative humidity. The growth rates of nitrate in SNA were significantly higher than those of sulfate on heavily polluted days. The values of SOR, NOR, and concentrations of SNA and SOA during higher AQI and humidity periods were higher than those in lower AQI and humidity periods. The Ox(NO2+O3) decreased with the increase in relative humidity. The SOA was higher at nighttime, increasing faster with the humidity than that in daytime. Under the situation of lower temperature, higher humidity, and lower wind speed, the emission of gaseous precursors of SNA requires further attention in Zhoukou in winter. Advanced control strategies of emissions of SO2 and NO2, such as mobile sources and coal-burning sources, could reduce the peak of haze in winter efficiently.

Bromodomain and extraterminal (BET) proteins: biological functions, diseases, and targeted therapy.

BET proteins, which influence gene expression and contribute to the development of cancer, are epigenetic interpreters. Thus, BET inhibitors represent a novel form of epigenetic anticancer treatment. Although preliminary clinical trials have shown the anticancer potential of BET inhibitors, it appears that these drugs have limited effectiveness when used alone. Therefore, given the limited monotherapeutic activity of BET inhibitors, their use in combination with other drugs warrants attention, including the meaningful variations in pharmacodynamic activity among chosen drug combinations. In this paper, we review the function of BET proteins, the preclinical justification for BET protein targeting in cancer, recent advances in small-molecule BET inhibitors, and preliminary clinical trial findings. We elucidate BET inhibitor resistance mechanisms, shed light on the associated adverse events, investigate the potential of combining these inhibitors with diverse therapeutic agents, present a comprehensive compilation of synergistic treatments involving BET inhibitors, and provide an outlook on their future prospects as potent antitumor agents. We conclude by suggesting that combining BET inhibitors with other anticancer drugs and innovative next-generation agents holds great potential for advancing the effective targeting of BET proteins as a promising anticancer strategy.

Interpretable Machine Learning Model Predicting Early Neurological Deterioration in Ischemic Stroke Patients Treated with Mechanical Thrombectomy: A Retrospective Study.

Early neurologic deterioration (END) is a common and feared complication for acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT). This study aimed to develop an interpretable machine learning (ML) model for individualized prediction to predict END in AIS patients treated with MT. The retrospective cohort of AIS patients who underwent MT was from two hospitals. ML methods applied include logistic regression (LR), random forest (RF), support vector machine (SVM), and extreme gradient boosting (XGBoost). The area under the receiver operating characteristic curve (AUC) was the main evaluation metric used. We also used Shapley Additive Explanation (SHAP) and Local Interpretable Model-Agnostic Explanations (LIME) to interpret the result of the prediction model. A total of 985 patients were enrolled in this study, and the development of END was noted in 157 patients (15.9%). Among the used models, XGBoost had the highest prediction power (AUC = 0.826, 95% CI 0.781-0.871). The Delong test and calibration curve indicated that XGBoost significantly surpassed those of the other models in prediction. In addition, the AUC in the validating set was 0.846, which showed a good performance of the XGBoost. The SHAP method revealed that blood glucose was the most important predictor variable. The constructed interpretable ML model can be used to predict the risk probability of END after MT in AIS patients. It may help clinical decision making in the perioperative period of AIS patients treated with MT.

Metastatic lymph nodes and prognosis assessed by the number of retrieved lymph nodes in gastric cancer.

BACKGROUND: The prognostic value of quantitative assessments of the number of retrieved lymph nodes (RLNs) in gastric cancer (GC) patients needs further study. AIM: To discuss how to obtain a more accurate count of metastatic lymph nodes (MLNs) based on RLNs in different pT stages and then to evaluate patient prognosis. METHODS: This study retrospectively analyzed patients who underwent GC radical surgery and D2/D2+ LN dissection at the Cancer Hospital of Harbin Medical University from January 2011 to May 2017. Locally weighted smoothing was used to analyze the relationship between RLNs and the number of MLNs. Restricted cubic splines were used to analyze the relationship between RLNs and hazard ratios (HRs), and X-tile was used to determine the optimal cutoff value for RLNs. Patient survival was analyzed with the Kaplan-Meier method and log-rank test. Finally, HRs and 95% confidence intervals were calculated using Cox proportional hazards models to analyze independent risk factors associated with patient outcomes. RESULTS: A total of 4968 patients were included in the training cohort, and 11154 patients were included in the validation cohort. The smooth curve showed that the number of MLNs increased with an increasing number of RLNs, and a nonlinear relationship between RLNs and HRs was observed. X-tile analysis showed that the optimal number of RLNs for pT1-pT4 stage GC patients was 26, 31, 39, and 45, respectively. A greater number of RLNs can reduce the risk of death in patients with pT1, pT2, and pT4 stage cancers but may not reduce the risk of death in patients with pT3 stage cancer. Multivariate analysis showed that RLNs were an independent risk factor associated with the prognosis of patients with pT1-pT4 stage cancer (P = 0.044, P = 0.037, P = 0.003, P < 0.001). CONCLUSION: A greater number of RLNs may not benefit the survival of patients with pT3 stage disease but can benefit the survival of patients with pT1, pT2, and pT4 stage disease. For the pT1, pT2, and pT4 stages, it is recommended to retrieve 26, 31 and 45 LNs, respectively.

[Characterization of Volatile Organic Compounds (VOCs) Using Mobile Monitoring Around the Industrial Parks in the Yangzte River Delta Region of China].

Volatile organic compounds (VOCs) play important roles in the formation of ozone and fine particles in the troposphere. Industrial parks emit significant amounts of VOCs in China, while few studies have characterized them. In the present study, a mobile platform was employed to measure the levels and composition VOCs around industrial parks in the Yangzte River Delta region. The average concentration of VOCs ranged from 39 µg·m-3 (5% percentile) to 533 µg·m-3 (95% percentile) with an average of 183 µg·m-3, which was three times that of ambient concentrations. Maximum VOC concentrations ranged from 307 µg·m-3 (5% percentile) to 12006 µg·m-3 (95% percentile) with an average of 2812 µg·m-3. The frequency of abnormal peak values was as high as 64% across all the industrial parks, of which toluene (32%), xylene (18%), benzene (9%), and>C9 aromatics (19%) were the most common species. Differences in VOC characteristics were observed among the different types of industrial parks. Specifically, highest concentrations of VOCs were observed in textile industrial parks followed by chemical, painting, and petrochemical industrial parks, and VOC concentrations in electronics industrial parks were the lowest. Importantly, species measured using the mobile platform only contributed~50% of VOCs present in ambient samples, indicating that the concentrations of VOCs in the industrial parks were underestimated overall. These results can inform measures to control VOC pollution in industrial parks in China.

Changing trends of clinicopathologic features and survival duration after surgery for gastric cancer in Northeast China.

BACKGROUND: Through analyzing the data from a single institution in Northeast China, this study revealed the possible clinicopathologic characteristics that influence the prognosis of patients with gastric cancer (GC). AIM: To evaluate the changing trends of clinicopathologic features and survival duration after surgery in patients with GC in Northeast China, which is a high-prevalence area of GC. METHODS: The study analyzed the difference in clinicopathologic features and survival duration after surgery of 5887 patients who were histologically diagnosed with GC at the Harbin Medical University Cancer Hospital. The study mainly analyzed the data in three periods, 2000 to 2004 (Phase 1), 2005 to 2009 (Phase 2), and 2010 to 2014 (Phase 3). RESULTS: Over time, the postoperative survival rate significantly increased from 2000 to 2014. In the past 15 years, compared with Phases 1 and 2, the tumor size was smaller in Phase 3 (P < 0.001), but the proportion of high-medium differentiated tumors increased (P < 0.001). The proportion of early GC gradually increased from 3.9% to 14.4% (P < 0.001). A surprising improvement was observed in the mean number of retrieved lymph nodes, ranging from 11.4 to 27.5 (P < 0.001). The overall 5-year survival rate increased from 24% in Phase 1 to 43.8% in Phase 3. Through multivariate analysis, it was found that age, tumor size, histologic type, tumor-node-metastasis stage, depth of invasion, lymph node metastasis, surgical approach, local infiltration, radical extent, number of retrieved lymph nodes, and age group were independent risk factors that influenced the prognosis of patients with GC. CONCLUSION: The clinical features of GC in Northeast China changed during the observation period. The increasing detection of early GC and more standardized surgical treatment effectively prolonged lifetimes.

Prognostic significance of Borrmann type combined with vessel invasion status in advanced gastric cancer.

BACKGROUND: Borrmann classification (types I-IV) for the detection of advanced gastric cancer has been accepted worldwide, and lymphatic and/or blood vessel invasion (LBVI) status is related to the poor prognosis after gastric cancer. AIM: To evaluate the significance of Borrmann type combined with LBVI status in predicting the prognosis of advanced gastric cancer. METHODS: We retrospectively studied the clinicopathological characteristics and long-term survival data of 2604 patients who were diagnosed with advanced gastric adenocarcinoma at Harbin Medical University Cancer Hospital from January 2009 to December 2013. Categorical variables were evaluated by the Pearson's χ 2 test, the Kaplan-Meier method was used to identify differences in cumulative survival rates, and the Cox proportional hazards model was used for multivariate prognostic analysis. RESULTS: A total of 2604 patients were included in this study. The presence of LVBI [LBVI (+)] and Borrmann type (P = 0.001), tumor location (P < 0.001), tumor size (P < 0.001), histological type (P < 0.001), tumor invasion depth (P < 0.001), number of metastatic lymph nodes (P < 0.001), and surgical method (P < 0.001) were significantly correlated with survival. When analyzing the combination of the Borrmann classification and LBVI status, we found that patients with Borrmann type III disease and LBVI (+) had a similar 5-year survival rate to those with Borrmann IV + LBVI (-) (16.4% vs 13.1%, P = 0.065) and those with Borrmann IV + LBVI (+) (16.4% vs 11.2%, P = 0.112). Subgroup analysis showed that the above results were true for any pT stage and any tumor location. Multivariate Cox regression analysis showed that Borrmann classification (P = 0.023), vascular infiltration (P < 0.001), tumor size (P = 0.012), pT stage (P < 0.001), pN stage (P < 0.001), and extent of radical surgery (P < 0.001) were independent prognostic factors for survival. CONCLUSION: Since patients with Borrmann III disease and LBVI (+) have the same poor prognosis as those with Borrmann IV disease, more attention should be paid to patients with Borrmann III disease and LBVI (+) during diagnosis and treatment, regardless of the pT stage and tumor location, to obtain better survival results.

[Audit Indicators and Suggested Ranges for Data Validation of Chemical Components in Ambient PM2.5: A Case Study of the Yangtze River Delta].

Diagnostic indicators for the validation of PM2.5 compositional data were calculated, based on the monitoring results of approximately 2100 ambient samples collected in the Yangzi River Delta from 2014 to 2017. According to the results of a correlation analysis, we propose that the audit indexes of the monitoring data of PM2.5 components in ambient air should include:equivalent ratios of anion-cation charge balance(A/C), the consistency between sum of all measured components(∑species) and weighed PM2.5, the consistency between mass reconstructed PM2.5(PM2.5, reconstructed) and weighed PM2.5, the chemical consistency between elemental S and water-soluble SO42-, elemental K and water-soluble K+, and the chemical consistency of theoretical and tested NH4+. The double-sided 95% reference ranges of anion-cation equivalent balance (A/C), ∑species/PM2.5, PM2.5, reconstructed/PM2.5, S/SO42-, and K/K+ ratios were determined in terms of P2.5 and P97.5 as follows:(0.82, 1.35), (0.63, 0.94), (0.62, 1.00), (0.28, 0.50), and (0.66, 2.31). These diagnostic indicators were helpful for judging the errors of chemical component analysis and retain seasonal variation stability. In most cases, NH4+ existed in the form of NH4NO3 and (NH4)2SO4 in spring and summer. With the approach of autumn and winter, it transformed to NH4NO3, (NH4)2SO4, and NH4Cl. The results of literature verification showed the pass rate of A/C was 87.1% and the rate of other indexes was 100%, indicating that the above audit indexes we propose could be applied to not only the Yangzi River Delta but the entire country. Furthermore, there were certain conditions in applying the diagnostic indicators. The S/SO42- ratio worked well with PM2.5 ≥ 40 µg·m-3 in summer and with 60 µg·m-3 ≤ PM2.5 ≤ 140 µg·m-3 in spring, autumn, and winter. Other audit indexes were available universally in all weathers under the condition of PM2.5 ≥ 60 µg·m-3.

[Observation of Aerosol Optical Properties and New Particle Formation in the Yangtze River Delta].

In a recent field campaign focused on air quality study, aerosol optical properties, particle number concentration, and PM2.5 components were monitored in Changzhou, Jiangsu Province, from May 27 to June 27, 2019. An array of instruments were deployed that included scanning mobility particle size spectrometer (SMPS), aethalometer (AE33), cavity attenuation phase shift single albedo monitor (CAPS-ALB), monitor for aerosols and gases in ambient air (MARGA) and RT-4 organic carbon/elemental carbon (OC/EC) carbon analyzer to study the ① changes in chemical composition and optical parameters of the new particles generated during the campaign period. ② comparison of the aerosol extinction coefficient recorded by these instruments and measured value in the reconstruction of IMPROVE (interagency monitoring of protected visual environment) and the calculated coefficient using MIE theory model were carried out. During the entire campaign, two new particle generation events were observed and also found that the particle size continued to increase from 4 nm to 64 nm. It was monitored that in the initial stage of new particle generation, sulfate contributed greatly. The measured average aerosol extinction coefficient during the period of particle generation, using these instruments was 95.40 Mm-1, while the average aerosol extinction reconstruction using the IMPROVE model was observed to be 140.20 Mm-1. The theoretical calculations based on Mie theory model yielded an average extinction coefficient of 93.54 Mm-1. It was found that the average aerosol extinction in Changzhou is lower than the average value of the urban aerosol extinction coefficient, which is measured to be 300 Mm-1 in China, during this period. The deployment of multiple instruments in a single campaign is more desirable because the combination of all observations helped in better characterization of the physicochemical properties of ambient aerosols from various aspects, including particle size spectrum and chemical composition.

Palladium-Catalyzed Synthesis and Anticancer Activity of Paclitaxel-Dehydroepiandrosterone Hybrids.

According to the activity-structure relationship of the C-13 side chain in paclitaxel or docetaxel, eighteen novel paclitaxel-dehydroepiandrosterone (DHEA) hybrids were designed and synthesized by Pd(II)-catalyzed Suzuki-Miyaura cross-coupling of 17-trifluoromethanesulfonic enolate-DHEA with different aryl boronic acids. The in vitro anticancer activity of the hybrids against a human liver cancer cell line (HepG-2) was evaluated by MTT assay, showing that most of these hybrids possessed moderate antiproliferative activity against the HepG-2 cancer cell line. Among these hybrids, three ones (7b, 7g, and 7i) with ortho-substituents in the phenyl group of the D-ring of DHEA analogues exhibited moderate anticancer activity. The optimal compound 7i showed superior anticancer activity against the HepG-2 cell line with an IC50 value of 26.39 µM.

[Secondary Aerosol Formation in Urban Shanghai: Insights into the Roles of Photochemical Oxidation and Aqueous-Phase Reaction].

Secondary species are one of the most important components of PM1 particles. To investigate the contributions as well as the factors that affect the formation of the secondary aerosols, a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS, AMS) was employed to characterize sub-micron particles (PM1) during spring and summer in urban Shanghai. Organics were dominant in PM1 particles and comprised around 55% of the total PM1 mass concentration, followed by sulfate (24%) and nitrate (10%). Positive matrix factorization was further applied to explore the sources of the organics. It was found that primary and secondary organic aerosols accounted for around 34% and 66% of the total organics, respectively. Three episodes were observed during the measurements, where secondary species increased substantially. Increases of secondary species were represented by increases of sulfate and LV-OOA1 in spring, especially during the noontime, thus indicating that their formation is promoted by photochemical oxidation; yet in summer, photochemical and aqueous chemistry together accelerate the formation of secondary species, as indicated by the good correlations between nitrate and aerosol liquid water as well as between SOA and Ox. Overall, we found that contributions from secondary organic and inorganic aerosols to total PM1 particles were 35.5% and 43%, respectively. This study highlights that the influence of photochemical and aqueous chemistry is significant in the promotion of secondary species formation in Shanghai.

Visible-Light-Mediated Oxidative Coupling of Vinylarenes with Bromocarboxylates Leading to γ-Ketoesters.

A photocatalytic strategy for the synthesis of γ-ketoesters was reported. Using DMSO as both the solvent and terminal oxidant, oxidative coupling of vinylarenes with bromocarboxylates proceeded readily, giving a variety of γ-ketoesters in good isolated yields and with a broad functional-group tolerance.

Cellular pharmacokinetics and pharmacodynamics mechanisms of ginkgo diterpene lactone and its modulation of P-glycoprotein expression in human SH-SY5Y cells.

Ginkgo diterpene lactone (GDL) is the raw material for ginkgo diterpene lactone meglumine injection, which is used for treating cerebral ischemia. The aims of this study were to explore the cellular pharmacokinetics of GDL in whole cells and subcellular fractions, and detect cellular pharmacodynamics on the human SH-SY5Y cells induced by oxygen-glucose deprivation and reoxygenation (OGD/R). Firstly, a simple, sensitive and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for assessing the amount of ginkgolide A (GA), B (GB) and K (GK) in cellular/subcellular samples. Then, phosphatidylserine and mitochondria membrane potential were assayed to evaluate the extent of apoptosis effect. The study showed that the cellular/subcellular accumulation of GA and GB were increased in a concentration-dependent manner; the levels of GA and GB in cytosol were the highest among these subcellular organelles. Meanwhile, GDL also attenuated the OGD/R-induced increases in the percentage of apoptotic and mitochondria membrane potential. In addition, verapamil increased the rate and amount of GA and GB entering cellular/subcellular compartments through inhibition of P-glycoprotein activity, and promoted the protective effect of GDL. The present study reports the cellular pharmacokinetics profiles of GA and GB in normal and OGD/R-induced SH-SY5Y cells in vitro for the first time, which provided valuable information for clinical safety application.

Preparation of oxazolines and oxazoles via a PhI(OAc)2-promoted cyclization of N-propargylamides.

A metal-free cyclization of N-propargylamides for the synthesis of various oxazolines and oxazoles via a 5-exo-dig process is presented. Using (diacetoxyiodo)benzene (PIDA) as a reaction promoter and lithium iodide (LiI) as an iodine source, intramolecular iodooxygenation of N-propargylamides proceeded readily, leading to the corresponding (E)-5-iodomethylene-2-oxazolines in good to excellent isolated yields. In addition, using the PhI(OAc)2/LiI system, N-propargylamides can be converted to the corresponding oxazole-5-carbaldehydes in the presence of oxygen under visible light irradiation. The resulting products can be further converted into various oxazoline and oxazole derivatives after simple derivatizations, and this method ultimately offers an efficient route to a variety of biologically active structures.

[Treatment Status and Emission Characteristics of Volatile Organic Compounds from Typical Industrial Sources].

The status of treatment equipment, the emission characteristics, and the ozone formation potential (OFP) of volatile organic compounds (VOCs) for 11 typical enterprises, which were categorized into the 8 major VOC emission industries identified by the emission inventory of a typical city in the Yangtze River Delta, are discussed in this paper. There was a large difference in the removal efficiency of non-methane hydrocarbon (NMHC) between different treatment techniques, and even an increase in concentration occurred after some of the treatments. The current treatment equipment for VOCs needs further optimization. The emissions of NMHC, benzene, toluene, and xylene in most of the surveyed enterprises exceeded their corresponding standards, with toluene the worst offender. The most abundant compounds in the eight emission industries were aromatic hydrocarbons and oxygenated VOCs, whereas aromatic hydrocarbons contributed the most to ozone formation potential. There were large differences in emission characteristics of VOCs from different industries. Priority should be placed on the industries that have large OFP when control strategies of VOCs are considered.

[Chemical Composition Characteristics of PM2.5 Emitted by Medium and Small Capacity Coal-fired Boilers in the Yangtze River Delta Region].

Seven small and medium coal-fired boilers were selected to analyze the emission factors and chemical composition characteristics of PM2.5, and the efficiency of the dust collection unit in removing PM2.5, OC, and EC of different particle sizes. At the outlet of the dust collection unit, PM2.5 mass emission factor was around 0.047-0.283 g·kg-1 with an average of (0.146±0.081) g·kg-1. SO42- was the most abundant ionic component, followed by NH4+ and Ca2+. S was the most abundant among all the elements, followed by Al, Ca, and Fe. The contents of OC and EC fluctuated greatly, and the ratio of OC and EC produced by each boiler was greater than one. In the range of the measured particle sizes, the mass concentration of PM2.5 showed a singlet or bimodal distribution, and the peak value appeared at 0.07-0.12 µm and greater than 1 µm in bimodal distribution. The mass concentration of OC showed a bimodal or trimodal distribution, and the peak value appeared at 0.04 µm, 0.20-0.31 µm, and greater than 1 µm in trimodal distribution. The efficiencies of the dust collection unit in removing PM2.5, OC, and EC were 66%, 53%, and 23%, respectively.

[Estimation of Fine Particle (PM2.5) Emission Inventory from Cooking: Case Study for Shanghai].

Cooking is one of important emission sources of fine particles (PM2.5). This study using the catering enterprises of Shanghai as an example, presents a method to estimate the PM2.5 emission inventory from cooking according to the number of stoves, cooking time, and number of customers. Based on in situ measurements, the concentrations of PM2.5 emissions ranged from 0.1 mg ·m-3 to 1.8 mg ·m-3, which exceeded the limit (1.0 mg ·m-3 for lampblack) in the national standard. Organic carbon dominated the PM2.5 emitted from cooking, accounting for more than 50%. Extremely high ratios of organic carbon to elemental carbon were observed, ranging from 58.8 to 752.3, which could be used as an indicator of cooking emissions. The emission factors of PM2.5 in the catering industry are closely related to the scale of the catering enterprises. The emission factors of large-and medium-sized enterprises are obviously higher than those of small and micro enterprises. The PM2.5 emissions of catering enterprises are mainly attributed to high emission loads of large enterprises and those for a large number of small and medium enterprises. The PM2.5 emission inventory of cooking in Shanghai was calculated according to the three emission factors above, and the results were very close. Therefore, the method for estimating the PM2.5 emission inventory for cooking presented in this study is helpful for other Chinese cities to calculate their PM2.5 emission inventory from cooking.

[Chemical Characterization, Spatial Distribution, and Source Identification of Organic Matter in PM2.5 in summertime Shanghai, China].

Particulate organic matter (POM) has attracted increasing attention recently due to its great contribution to fine particles (PM2.5) and complex components and sources. In the present study, 78 particulate organic compounds in PM2.5 were quantified at three sites in Shanghai during summer; these sites were located in urban (Xuhui), suburban (Qingpu), and coastal (Lin'gang) areas of the city. Accordingly, the chemical composition and spatial distribution were investigated and sources were explored based on the indicators and diagnostic ratios combined with backward trajectory. The results showed that during the period of observation, the quantified organic matter in the suburban area is about 319 ng ·m-3, close to the urban area but much higher than that of the coastal areas. Fatty acids were the largest contributors, followed by levoglucosan, polycyclic aromatic hydrocarbons (PAHs), n-alkanes, and hopanes. Source analysis based on tracer methods indicates that gasoline vehicle emissions were the main source of POM in Shanghai. Biomass burning from the northeast impacted somewhat on the urban area and western suburbs during the observation period. Terrestrial plant emissions played an important role in the source of fatty acids at Qingpu and Lin'gang, and emissions of marine phytoplankton and microorganisms were also important for fatty acids at Lin'gang. Coal combustion and motor vehicle exhaust made an important contribution to PAHs according to an analysis of diagnostic ratios. This study presented the characteristics and sources of POM in summertime Shanghai, which facilitates the development of an effective control strategy on PM2.5 pollution.

An ultra-sensitive Abbott ARCHITECT® assay for the detection of hepatitis B virus surface antigen (HBsAg).

BACKGROUND: Critical to the identification of HBV infection and the prevention of transfusion transmitted disease is the sensitive and accurate detection of Hepatitis B virus surface antigen (HBsAg). Improvements in HBsAg assay sensitivity approaching the performance of nucleic acid testing (NAT) are essential to further reduce the detection window for acute HBV infection in regions where NAT is not widely available. OBJECTIVES AND STUDY DESIGN: An improved HBsAg assay on the fully-automated Abbott ARCHITECT® platform was developed to improve sensitivity, mutant and genotype detection. RESULTS: The analytical sensitivity of the improved prototype assay is 5.2 mIU/ml, which is 3.86- to 14.54-fold more sensitive than comparator assays based on the WHO International Reference Standard. The enhanced sensitivity was also demonstrated with 27 HBV seroconversion panels, detecting more panel members (191 of 364) vs. the ARCHITECT® Qual I (144), Qual II (160) and PRISM® (148) HBsAg assays. Further, the assay detected 7 of 12 HBV DNA positive/HBsAg negative samples, and detected all evaluated mutants and genotypes with higher sensitivity than the comparator assays. The improvement in sensitivity did not diminish assay specificity, attaining 100% (95% CI, 99.97-100%) on 10,633 blood donors. CONCLUSIONS: An Abbott ARCHITECT® HBsAg assay with clinical performance approaching that of mini-pool NAT (approximately 100 copies/ml was developed. The assay has superior HBsAg mutant and genotype detection and specificity, all of which are important for the diagnosis and management of HBV infection.