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Sixteen parent PAHs and twelve nitro-PAHs were measured in PM2.5 samples collected over one year (2013–2014) at nine urban sites in China. During the sampling period, concentrations of individual nitro-PAHs were one or two orders of magnitude lower than their parent PAHs. Typical seasonal variations in parent PAH concentrations, which increased 10- to 80- fold in winter compared to summer, were observed in this study. Conversely, the mean atmospheric concentrations of nitro-PAHs were similar in all four seasons, with the exception of 9-nitroanthracene (9n-Ant). Compared to other nitro-PAHs which were secondary formation products, 9n-Ant had a higher concentration and made up a larger proportion of total nitro-PAHs. Positive matrix factorization results indicated that 9n-Ant sources included biomass burning (20%), vehicle exhaust emissions (43%), and secondary formation (30%). Overall, the elevated concentrations of parent PAHs observed in winter correlated with the contribution from coal combustion at all sites, especially in north China (>80%). The contribution of secondary formation products to total nitro-PAHs was measured during the summer, and was especially high in the larger cities such as Shanghai (84%), Beijing (76%), Guangzhou (60%), and Chengdu (64%), largely due to the summer concentrations of parent PAHs were markedly lower than in winter.

Incomplete understanding of the sources of secondary organic aerosol (SOA) leads to large uncertainty in both air quality management and in climate change assessment. Chemical reactions occurring in the atmospheric aqueous phase represent an important source of SOA mass, yet, the effects of anthropogenic emissions on the aqueous SOA (aqSOA) are not well constrained. Here we use compound-specific dual-carbon isotopic fingerprints (δ 13 C and Δ 14 C) of dominant aqSOA molecules, such as oxalic acid, to track the precursor sources and formation mechanisms of aqSOA. Substantial stable carbon isotope fractionation of aqSOA molecules provides robust evidence for extensive aqueous-phase processing. Contrary to the paradigm that these aqSOA compounds are largely biogenic, radiocarbon-based source apportionments show that fossil precursors produced over one-half of the aqSOA molecules. Large fractions of fossil-derived aqSOA contribute substantially to the total water-soluble organic aerosol load and hence impact projections of both air quality and anthropogenic radiative forcing. Our findings reveal the importance of fossil emissions for aqSOA with effects on climate and air quality. Isotope fingerprinting is used to track precursor sources and formation pathways of aqueous SOA, such as oxalic acid, finding that fossil fuel precursors contributions have largely been underestimated.

To develop, validate, and visualize a risk prediction model for postoperative shivering in patients undergoing video-assisted thoracoscopic (VATS) lobectomy, addressing the lack of individualized tools for this high-risk population. This retrospective study analyzed 530 patients undergoing VATS lobectomy from a tertiary hospital in Wuhan (January 2022–December 2023). The data were randomly divided into training set and validation set at a ratio of 7∶3. Patients were stratified into postoperative shivering ( n  = 198) and non-postoperative shivering ( n  = 332) groups based on Bedside Shivering Assessment Scale (BSAS) criteria. Logistic regression identified independent risk factors, and a nomograph was developed. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC), calibration curves, Hosmer-Lemeshow test, and decision curve analysis (DCA). An online visualization tool was created for clinical implementation. Postoperative shivering occurred in 198 of 530 patients undergoing VATS lobectomy (37.36%). The logistic regression analysis identified age < 60 years, intraoperative hypothermia, delayed anesthesia recovery, absence of postoperative analgesia, operation duration > 180 min and lower preoperative temperature as significant risk factors for postoperative shivering ( P  < 0.05). The resulting nomograph demonstrated strong discrimination with AUCs of 0.847 (95% CI : 0.809–0.885) in the training cohort ( n  = 424) and 0.836 (95% CI : 0.747–0.925) in validation ( n  = 106), while calibration curves and the Hosmer-Lemeshow test ( χ 2  = 13.123, P  = 0.108) confirmed model reliability. DCA demonstrated clinical utility across threshold probabilities of 0.20–0.98. In order to promote clinical implementation, deployment of the visualization tools online ( https://shivering.shinyapps.io/dynnomapp/ ), which supports dynamic risk assessment. This study established the first risk prediction model for postoperative shivering in patients undergoing VATS lobectomy, integrating six perioperative variables into a clinically applicable nomograph and online tool. The model facilitates identification of high-risk patients, enabling targeted interventions to mitigate shivering-related complications.

This study aimed to develop and internally validate a nomogram model for assessing the risk of intraoperative hypothermia in patients undergoing video-assisted thoracoscopic (VATS) lobectomy. This study is a retrospective study. A total of 530 patients who undergoing VATS lobectomy from January 2022 to December 2023 in a tertiary hospital in Wuhan were selected. Patients were divided into hypothermia group (n = 346) and non-hypothermia group (n = 184) according to whether hypothermia occurred during the operation. Lasso regression was used to screen the independent variables. Logistic regression was used to analyze the risk factors of hypothermia during operation, and a nomogram model was established. Bootstrap method was used to internally verify the nomogram model. Receiver operating characteristic (ROC) curve was used to evaluate the discrimination of the model. Calibration curve and Hosmer Lemeshow test were used to evaluate the accuracy of the model. Decision curve analysis (DCA) was used to evaluate the clinical utility of the model. Intraoperative hypothermia occurred in 346 of 530 patients undergoing VATS lobectomy (65.28%). Logistic regression analysis showed that age, serum total bilirubin, inhaled desflurane, anesthesia duration, intraoperative infusion volume, intraoperative blood loss and body mass index were risk factors for intraoperative hypothermia in patients undergoing VATS lobectomy ( P  < 0.05). The area under ROC curve was 0.757, 95% CI (0.714–0.799). The optimal cutoff value was 0.635, the sensitivity was 0.717, and the specificity was 0.658. These results suggested that the model was well discriminated. Calibration curve has shown that the actual values are generally in agreement with the predicted values. Hosmer–Lemeshow test showed that χ2 = 5.588, P  = 0.693, indicating that the model has a good accuracy. The DCA results confirmed that the model had high clinical utility. The nomogram model constructed in this study showed good discrimination, accuracy and clinical utility in predicting patients with intraoperative hypothermia, which can provide reference for medical staff to screen high-risk of intraoperative hypothermia in patients undergoing VATS lobectomy.

The occurrence and distribution of 11 antibiotics in multiple environmental media including river water, suspended particle, sediment, and soil of the East River catchment, South China, were systematically characterized from multiple spatial (area and point) and temporal (seasonal variation and diurnal variation) scales. The results indicated that six to eight antibiotics were detected in these media. The predominant antibiotics and their concentrations varied with environment media because of the varied contamination sources, physicochemical properties of antibiotics, and media. For their spatial distribution, the river environment including water phase, suspended particles, and sediments showed a similar feature with the rule of C delta  >  C lower reach  >  C middle reach , which may be related to the industrial level and population density. However, the antibiotics in the soils showed a close relationship with the land use types. A diurnal variation of antibiotics at river sections was mainly affected by the tidal change and diurnal domestic sewage discharge feature. Source analysis indicated that domestic sewage was the main source for antibiotic contamination in the river, while irrigation and fertilization using river water and animal wastes were the main reasons for antibiotic contamination in the soils. However, antibiotics may be redistributed in different media in a catchment.

Fine carbonaceous aerosols (CAs) is the key factor influencing the currently filthy air in megacities in China, yet few studies simultaneously focus on the origins of different CAs species using specific and powerful source tracers. Here, we present a detailed source apportionment for various CAs fractions, including organic carbon (OC), water-soluble OC (WSOC), water-insoluble OC (WIOC), elemental carbon (EC) and secondary OC (SOC) in the largest cities of North (Beijing, BJ) and South China (Guangzhou, GZ), using the measurements of radiocarbon and anhydrosugars. Results show that non-fossil fuel sources such as biomass burning and biogenic emission make a significant contribution to the total CAs in Chinese megacities: 56 ± 4 in BJ and 46 ± 5 % in GZ, respectively. The relative contributions of primary fossil carbon from coal and liquid petroleum combustions, primary non-fossil carbon and secondary organic carbon (SOC) to total carbon are 19, 28 and 54 % in BJ, and 40, 15 and 46 % in GZ, respectively. Non-fossil fuel sources account for 52 in BJ and 71 % in GZ of SOC, respectively. These results suggest that biomass burning has a greater influence on regional particulate air pollution in North China than in South China. We observed an unabridged haze bloom-decay process in South China, which illustrates that both primary and secondary matter from fossil sources played a key role in the blooming phase of the pollution episode, while haze phase is predominantly driven by fossil-derived secondary organic matter and nitrate.

We measured the radiocarbon isotope signals in various fractions of carbonaceous aerosols sampled across four seasons (Oct 2013−Jul 2014) in three megacities of China, viz., Beijing, Shanghai, and Guangzhou. The contributions of fossil fuel (FF) and non-fossil fuel (NF) to the carbonaceous aerosol were estimated based on the radiocarbon content in the organic carbon (OC), water-soluble organic carbon (WSOC), water-insoluble organic carbon (WIOC), and elemental carbon (EC). Although NF generated the primary share (> 55%) during autumn in all of the cities, the seasonal contributions of the sources differed by location during the rest of the year. During winter, FF emissions constituted the majority of the carbonaceous pollution (64%) in Beijing, probably as a result of increased coal combustion for heating. On average, the EC, WSOC, and WIOC generated by FF composed ~10%, 35%, and 19% of the total carbon (TC). Overall, NF was identified as the largest source of carbonaceous aerosol in Guangzhou (63%), whereas FF was the largest source, contributing slightly more than NF, in Shanghai (54%). During spring and summer, FF played a greater role than NF in Beijing (~55%) and Guangzhou (~63%); additionally, based on our limited number of samples, it contributed 71% in Shanghai during the latter season, with a significant portion due to fuel combustion (i.e., industrial, vehicular, fishing-boat, and large-vessel emissions).

Historical reconstructions of fossil fuel carbon dioxide emissions are vital to setting emission mitigation strategies, and tree-ring radiocarbon analysis provides a reliable approach. However, residual radiocarbon from past nuclear tests can distort the signal, and regional variations beyond the well-known latitudinal gradient remain underexplored. Here we analyzed tree-ring radiocarbon records from Nanling (1921–2020, this study) and published datasets to identify spatial patterns of bomb-derived fallout in China from 1965 to 1985. Compared to latitudinal compilations and European backgrounds, radiocarbon enhancements extended up to 3000 km from test sites, highlighting the dominant role of source characteristics. We further demonstrate that re-release of bomb radiocarbon from terrestrial ecosystems prolongs its regional atmospheric residence time to 5–20 years, introducing spatial variability that biases fossil fuel carbon dioxide reconstructions up to 5.4 ppm. These findings underscore the need to integrate source-specific fallout and atmospheric transport into regional radiocarbon interpretation frameworks. Residual radiocarbon emissions from past nuclear bomb testing can extend 3000 km and therefore skew tree-ring carbon dioxide reconstructions, according to analysis of tree-ring samples from China.

Water-insoluble organic carbon (WIOC) constitutes a substantial portion of organic carbon (OC) and contributes significantly to light absorption by brown carbon (BrC), playing pivotal roles in climate forcing. China is a hotspot region with high levels of OC and BrC, but information regarding the sources and light-absorbing properties of WIOC on a national scale remains scarce. Here, we investigated the light-absorbing properties and sources of WIOC in 10 representative urban cities in China. On average, WIOC made up 33.4 ± 7.66 % and 40.5 ± 9.73 % of concentrations and light absorption at 365 nm (Abs365) of extractable OC (EX-OC), which includes relatively hydrophobic OC (WIOC and humic-like substances, HULIS-C) and hydrophilic OC (non-humic-like substances, non-HULIS-C). The mass absorption efficiency of WIOC at 365 nm (MAE365) was (1.59 ± 0.55 m2 (g C)−1) comparable to that of HULIS (1.54 ± 0.57 m2 (g C)−1) but significantly higher than non-HULIS (0.71 ± 0.28 m2 (g C)−1), indicating that hydrophobic OC possesses a stronger light-absorbing capacity than hydrophilic OC. Biomass burning (31.0 %) and coal combustion (31.1 %) were the dominant sources of WIOC, with coal combustion sources exhibiting the strongest light-absorbing capacity. Moreover, employing the simple forcing efficiency (SFE300–700 nm) method, we observed that WIOC exhibited the highest SFE300–700 nm (6.57 ± 5.37 W g−1) among the EX-OC fractions. The radiative forcing of EX-OC was predominantly contributed by hydrophobic OC (WIOC – 39.4 ± 15.5 % and HULIS – 39.5 ± 12.1 %). Considering the aromaticity, sources, and atmospheric processes of different carbonaceous components, we propose a light-absorbing carbonaceous continuum, revealing that components enriched with fossil sources tend to possess stronger light-absorbing capacity, higher aromatic levels, increased molecular weights, and greater recalcitrance in the atmosphere. Reducing fossil fuel emissions emerges as an effective means of mitigating both gaseous (CO2) and particulate light-absorbing carbonaceous warming components.

Water-insoluble organic carbon (WIOC) constitutes a substantial portion of organic carbon (OC) and contributes significantly to light absorption by brown carbon (BrC), playing pivotal roles in climate forcing. China is a hotspot region with high levels of OC and BrC, but information regarding the sources and light-absorbing properties of WIOC on a national scale remains scarce. Here, we investigated the light-absorbing properties and sources of WIOC in 10 representative urban cities in China. On average, WIOC made up 33.4 ± 7.66 % and 40.5 ± 9.73 % of concentrations and light absorption at 365 nm (Abs.sub.365) of extractable OC (EX-OC), which includes relatively hydrophobic OC (WIOC and humic-like substances, HULIS-C) and hydrophilic OC (non-humic-like substances, non-HULIS-C). The mass absorption efficiency of WIOC at 365 nm (MAE.sub.365) was (1.59 ± 0.55 m.sup.2 (g C).sup.-1) comparable to that of HULIS (1.54 ± 0.57 m.sup.2 (g C).sup.-1) but significantly higher than non-HULIS (0.71 ± 0.28 m.sup.2 (g C).sup.-1 ), indicating that hydrophobic OC possesses a stronger light-absorbing capacity than hydrophilic OC. Biomass burning (31.0 %) and coal combustion (31.1 %) were the dominant sources of WIOC, with coal combustion sources exhibiting the strongest light-absorbing capacity. Moreover, employing the simple forcing efficiency (SFE.sub.300-700 nm) method, we observed that WIOC exhibited the highest SFE.sub.300-700 nm (6.57 ± 5.37 W g.sup.-1) among the EX-OC fractions. The radiative forcing of EX-OC was predominantly contributed by hydrophobic OC (WIOC - 39.4 ± 15.5 % and HULIS - 39.5 ± 12.1 %). Considering the aromaticity, sources, and atmospheric processes of different carbonaceous components, we propose a light-absorbing carbonaceous continuum, revealing that components enriched with fossil sources tend to possess stronger light-absorbing capacity, higher aromatic levels, increased molecular weights, and greater recalcitrance in the atmosphere. Reducing fossil fuel emissions emerges as an effective means of mitigating both gaseous (CO.sub.2) and particulate light-absorbing carbonaceous warming components.