Nanoconfined Silver Nanoclusters Combined with X-Shaped DNA Recognizer-Triggered Cascade Amplification for Electrochemiluminescence Detection of APE1.

Apurinic/apyrimidinic endonuclease 1 (APE1), as a vital base excision repair enzyme, is essential for maintaining genomic integrity and stability, and its abnormal expression is closely associated with malignant tumors. Herein, we constructed an electrochemiluminescence (ECL) biosensor for detecting APE1 activity by combining nanoconfined ECL silver nanoclusters (Ag NCs) with X-shaped DNA recognizer-triggered cascade amplification. Specifically, the Ag NCs were prepared and confined in the glutaraldehyde-cross-linked chitosan hydrogel network using the one-pot method, resulting in a strong ECL response and exceptional stability in comparison with discrete Ag NCs. Furthermore, the self-assembled X-shaped DNA recognizers were designed for APE1 detection, which not only improved reaction kinetics due to the ordered arrangement of recognition sites but also achieved high sensitivity by utilizing the recognizer-triggered cascade amplification of strand displacement amplification (SDA) and DNAzyme catalysis. As expected, this biosensor achieved sensitive ECL detection of APE1 in the range of 1.0 × 10-3 U·µL-1 to 1.0 × 10-10 U·µL-1 with the detection limit of 2.21 × 10-11 U·µL-1, rendering it a desirable approach for biomarker detection.

Burnout among radiology residents: a systematic review and meta-analysis.

OBJECTIVE: To analyze the prevalence of burnout among radiology residents. METHOD: Five databases (PubMed, Web of Science, Embase, PsycINFO, and Scopus) were searched for studies reporting burnout in radiology residents for the period up to November 7, 2022. RESULTS: A total of 423 studies were identified, and eventually, 16 studies were selected for the qualitative analysis, of which 11 studies were used in the meta-analysis. There was a total of 2164 radiology residents. Six studies reported the prevalence of burnout but the data could not be pooled due to their inconsistent definitions of burnout. The mean scores of three burnout subscales indicated a moderate to high degree of severity: emotional exhaustion = 25.2 (95% CI, 22.1-28.3; I2 = 94.4%), depersonalization = 10.2 (95% CI, 8.5-11.9; I2 = 93.0%), and low perception of personal accomplishment = 32.9 (95% CI, 30.5-35.4; I2 = 94.4%). The pooled prevalence of high-degree emotional exhaustion was 49.9% (95% CI, 43.6-56.1%; I2 = 55.7%), high-degree depersonalization was 45.1% (95% CI, 38.3-52.0%; I2 = 63.2%), and high-degree diminished personal accomplishment was 58.2% (95% CI, 36.0-77.6%; I2 = 84.9%). The impact of the COVID-19 pandemic on radiology residents was not investigated. In addition, there are inconsistent findings on the effects of female sex, seniority, and social support on burnout. CONCLUSIONS: About half of the radiology residents showed at least one of the three burnout manifestations (emotional exhaustion, depersonalization, and personal accomplishment), with a moderate to high degree of severity. CLINICAL RELEVANCE STATEMENT: Such a high prevalence and severity of burnout among radiology residents warrant the attention of residency program directors. KEY POINTS: • Burnout, not uncommon among radiology residents, has not been effectively analyzed. • Nearly half of the radiology residents experience at least one of the three manifestations of burnout to a moderate to high degree. • The high prevalence and severe degree of burnout among radiology residents warrant the attention of residency program directors.

Mechanical guidance to self-organization and pattern formation of stem cells.

The self-organization of stem cells (SCs) constitutes the fundamental basis of the development of biological organs and structures. SC-driven patterns are essential for tissue engineering, yet unguided SCs tend to form chaotic patterns, impeding progress in biomedical engineering. Here, we show that simple geometric constraints can be used as an effective mechanical modulation approach that promotes the development of controlled self-organization and pattern formation of SCs. Using the applied SC guidance with geometric constraints, we experimentally uncover a remarkable deviation in cell aggregate orientation from a random direction to a specific orientation. Subsequently, we propose a dynamic mechanical framework, including cells, the extracellular matrix (ECM), and the culture environment, to characterize the specific orientation deflection of guided cell aggregates relative to initial geometric constraints, which agrees well with experimental observation. Based on this framework, we further devise various theoretical strategies to realize complex biological patterns, such as radial and concentric structures. Our study highlights the key role of mechanical factors and geometric constraints in governing SCs' self-organization. These findings yield critical insights into the regulation of SC-driven pattern formation and hold great promise for advancements in tissue engineering and bioactive material design for regenerative application.

High-Temperature Phase Transition with Switchable Dielectric Behavior and Significant Photoluminescence Changes in a Zero-Dimensional Hybrid SbBr6 Perovskite.

In the past decade, metal halide materials have been favored by many researchers because of their excellent physical and chemical properties under thermal, electrical, and light stimuli, such as ferroelectricity, dielectric, nonlinearity, fluorescence, and semiconductors, greatly promoting their application in optoelectronic devices. In this study, we successfully constructed an unleaded organic-inorganic hybrid perovskite crystal: [Cl-C6H4-(CH2)2NH3]3SbBr6 (1), which underwent a high-temperature reversible phase transition near Tp = 368 K. The phase transition behavior of 1 was characterized by differential scanning calorimetry, accompanied by a thermal hysteresis of 6 K. In addition, variable-temperature Raman spectroscopy analysis and PXRD further verified the sensitivity of 1 to temperature and the phase transition from low symmetry to high symmetry. Temperature-dependent dielectric testing shows that 1 can be a sensitive switching dielectric constant switching material. Remarkably, 1 exhibits strong photoluminescence emission with a wavelength of 478 nm and a narrow band gap of 2.7 eV in semiconductors. As the temperature increases and decreases, fluorescence undergoes significant changes, especially near Tc, which further confirms the reversible phase transition of 1. All of these findings provide new avenues for designing and assembling new phase change materials with high Tp and photoluminescence properties.

Effect of volatile versus propofol anaesthesia on major complications and mortality after cardiac surgery: a multicentre randomised trial.

BACKGROUND: The comparative effectiveness of volatile anaesthesia and total intravenous anaesthesia (TIVA) in terms of patient outcomes after cardiac surgery remains a topic of debate. METHODS: Multicentre randomised trial in 16 tertiary hospitals in China. Adult patients undergoing elective cardiac surgery were randomised in a 1:1 ratio to receive volatile anaesthesia (sevoflurane or desflurane) or propofol-based TIVA. The primary outcome was a composite of predefined major complications during hospitalisation and mortality 30 days after surgery. RESULTS: Of the 3123 randomised patients, 3083 (98.7%; mean age 55 yr; 1419 [46.0%] women) were included in the modified intention-to-treat analysis. The composite primary outcome was met by a similar number of patients in both groups (volatile group: 517 of 1531 (33.8%) patients vs TIVA group: 515 of 1552 (33.2%) patients; relative risk 1.02 [0.92-1.12]; P=0.76; adjusted odds ratio 1.05 [0.90-1.22]; P=0.57). Secondary outcomes including 6-month and 1-yr mortality, duration of mechanical ventilation, length of ICU and hospital stay, and healthcare costs, were also similar for the two groups. CONCLUSIONS: Among adults undergoing cardiac surgery, we found no difference in the clinical effectiveness of volatile anaesthesia and propofol-based TIVA. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR-IOR-17013578).

TWIK-related acid-sensitive potassium channels TASK-1 and TASK-3 may participate in the process of the coexistence of asthma and OSA.

OBJECTIVE: To investigate the role of TWIK-related acid-sensitive potassium channels TASK-1 and TASK-3 in the mechanism of asthma combined with obstructive sleep apnea (OSA) in mice. METHOD: C57BL/6 mice were randomly divided into four groups: control group (NS-RA), asthma group (OVA-RA), OSA group (NS-IH), and asthma combined with OSA group (OVA-IH). After monitoring lung function in each group, the expression levels of TASK-1 and TASK-3 mRNA and protein in lung tissues were measured, and the correlation between the changes of both and lung function was analyzed. RESULTS: A total of 64 male mice were studied. Penh, serum IgE concentrations, and the percentage of eosinophils in bronchoalveolar lavage fluid (BALF) were higher in OVA-RA and OVA-IH mice compared with NS-RA (P < 0.05),while the above indexes were slightly elevated in NS-IH mice compared with NS-RA (P > 0.05), where the Penh and the percentage of eosinophils in BALF was higher in OVA-IH mice than NS-IH (P < 0.05).Increased TASK-3 mRNA expression (P < 0.05) as well as TASK-1 and TASK-3 protein expression (P > 0.05) in lung tissues of OVA-RA and NS-IH mice compared with NS-RA, and TASK-3 mRNA expression was slightly more in the OVA-IH group compared with NS-RA (P > 0.05), but less compared with OVA-RA (P < 0.05) or NS-IH (P > 0.05), while TASK-1 and TASK-3 protein expression was increased in the OVA-IH group compared with the remaining three groups, and TASK-3 protein expression was associated with lung function impairment was positively correlated with the degree of lung function impairment (P < 0.05). CONCLUSION: Task-1 and Task-3 may be involved in the pathogenesis of asthma with OSA by affecting lung function.

[Oblique Lumbar Interbody Fusion Combined With 4-Screw Fixation for Treating Two-Level Degenerative Lumbar Diseases:A Finite Element Study].

Objective To demonstrate the feasibility of oblique lumbar interbody fusion (OLIF) combined with 4-screw fixation for treating two-level lumbar degenerative diseases.Methods An intact finite element model of L3-S1 (M0) was constructed and validated.Then,we constructed the M1 model by simulating OLIF surgery at L3/4 and L4/5 segments on the M0 model.By attachment of posterior 4-screw or 6-screw fixation to the M1 model,three 4-screw fixation models (M2-M4) and one 6-screw fixation model (M5) were established.The segmental and overall range of motion (ROM) and the peak von Mises stresses of superior endplate,cage,and posterior screw-rod were investigated under each implanted condition.Results Under the motion modes of forward flexion,backward extension,bilateral (left and right) flexion,and left and right rotation,the L3/4 ROM of M2 model and L4/5 ROM of M3 model increased,while the L3/4 and L4/5 ROM of M4 and M5 models significantly decreased compared with those of M1 model.Under all motion modes,the L4 superior endplate in M2 model and the L5 superior endplate in M3 model showed the maximum peak von Mises stress,and the peak von Mises stresses of L4 and L5 superior endplates in M4 and M5 models were close.The L3/4 cage in M2 model and the L4/5 cage in M3 model showcased the largest peak von Mises stress,and the peak von Mises stresses of cages in M4 and M5 models were close.The peak stresses of internal fixation in M2-M5 models were close.Conclusion Four-screw fixation can replace 6-screw fixation in the OLIF surgery for treating two-level degenerative lumbar diseases.

[Mechanism of traditional Chinese medicine in regulating NLRP3 inflammasomes to alleviate renal interstitial fibrosis in diabetic nephropathy: a review].

Diabetic nephropathy(DN), a progressive chronic kidney disease(CKD) induced by diabetes mellitus, is the main cause of end-stage renal disease. Renal interstitial fibrosis(RIF) is an irreversible factor in the progression and deterioration of the renal function in DN. Chronic inflammation has become a key link in the pathogenesis of DN-RIF. The NOD-like receptor thermal protein domain associated protein 3(NLRP3) inflammasome is an important inflammatory regulator regulated by a variety of signals. It promotes the production of pro-inflammatory cytokines and induces renal inflammatory cell infiltration to participate in the process of renal fibrosis, demonstrating a complex mechanism of action. In view of the important role of NLRP3 inflammasomes in the prevention and treatment of DN-RIF, a large number of experimental studies have demonstrated that traditional Chinese medicine(TCM) can reduce the inflammation by regulating the pathways involving NLRP3 inflammasome, thereby slowing down the progression of DN-RIF and improving the renal function. This paper reviews the relationship between NLRP3 inflammasomes and DN-RIF, and the research progress in the mechanism of TCM intervention in NLRP3 inflammasomes to alleviate DN-RIF, aiming to provide new ideas for the targeted treatment of DN-RIF.

Zero-Dimensional Sn-Based Enantiomeric Phase-Transition Materials with High-Tc and Dielectric Switching.

The combination of chirality and phase-transition materials has broad application prospects. Therefore, based on the quasi-spherical theory and the thought strategy of introducing chirality, we have successfully synthesized a pair of chiral enantiomeric ligands (R/S)-triethyl-(2-hydroxypropyl)ammonium iodide, which can be combined with a tin hexachloride anion to obtain a pair of new organic-inorganic hybrid enantiomeric high-temperature plastic phase-transition materials: (R/S)-[CH3 CH(OH)CH2 N(CH2 CH3 )3 ]2 SnCl6 (1-R/1-S), which have a high temperature phase transition of Tc =384 K, crystallize in the P21 chiral space group at room temperature, and have obvious CD signals. In addition, compounds 1-R and 1-S have a good low-loss dielectric switch and broadband gap. This work is conducive to the research into chiral high-temperature reversible plastic phase-transition materials, and promotes the development of multi-functional phase-transition materials.

Concentrations, Profiles, and Health Risks of Organic Ultraviolet Filters in Eight Food Categories Determined through the Sixth Chinese Total Diet Study.

Ultraviolet (UV) filters are emerging contaminants that have been found in high concentrations in human tissues. Food intake is generally considered to be the primary route of human exposure to contaminants. In this study, 184 composite food samples, prepared from 4268 individual samples in eight categories collected from 23 Chinese provinces for the sixth Chinese total diet study, were analyzed. The total and median UV filter concentrations in food samples were 1.5-68.3 and 7.9 ng/g wet weight, respectively. The highest median concentrations were found in decreasing order in meat, cereals, and legumes. In total, 15 UV filters were analyzed. 2-Ethylhexyl salicylate, homosalate, and 2-ethylhexyl-4-methoxycinnamate were dominant and made median contributions of 34.1%, 22.6%, and 14.5%, respectively, and 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol contributed the median of 0.03%, of the total UV filter concentrations. The estimated total daily UV filter intake in animal-origin foods and total UV filter concentration in human milk from the same province were significantly correlated (r = 0.44, p < 0.05). Predicted absorption, distribution, metabolism, and elimination properties led to 10 UV filters being prioritized as most likely to be retained in human tissues. The prioritization results and toxicity assessments indicated that octocrylene and 2-ethylhexyl-4-methoxycinnamate have stronger effects in vivo and therefore require more attention than others.

Health Risks Posed by Dermal and Inhalation Exposure to High Concentrations of Chlorinated Paraffins Found in Soft Poly(vinyl chloride) Curtains.

Chlorinated paraffins (CPs) are used in many products, including soft poly(vinyl chloride) curtains, which are used in many indoor environments. Health hazards posed by CPs in curtains are poorly understood. Here, chamber tests and an indoor fugacity model were used to predict CP emissions from soft poly(vinyl chloride) curtains, and dermal uptake through direct contact was assessed using surface wipes. Short-chain and medium-chain CPs accounted for 30% by weight of the curtains. Evaporation drives CP migration, like for other semivolatile organic plasticizers, at room temperature. The CP emission rate to air was 7.09 ng/(cm2 h), and the estimated short-chain and medium-chain CP concentrations were 583 and 95.3 ng/m3 in indoor air 21.2 and 172 µg/g in dust, respectively. Curtains could be important indoor sources of CPs to dust and air. The calculated total daily CP intakes from air and dust were 165 ng/(kg day) for an adult and 514 ng/(kg day) for a toddler, and an assessment of dermal intake through direct contact indicated that touching just once could increase intake by 274 µg. The results indicated that curtains, which are common in houses, could pose considerable health risks through inhalation of and dermal contact with CPs.

Enhanced Cell Wall and Cell Membrane Activity Promotes Heat Adaptation of Enterococcus faecium.

Enterococcus faecium (E. faecium) is widely used in foods and is known as a probiotic to treat or prevent diarrhea in pets and livestock. However, the poor resistance of E. faecium to high temperature processing procedures limits its use. Strain domestication is a low-cost and effective method to obtain high-temperature-resistant strains. In this study, heat treatment was performed from 45 °C to 70 °C and the temperature was gradually increased by 5 °C every 3 days. After domestication, the survival rates of the high temperature adaptation strain RS047-wl under 65 °C water bath for 40 min was 11.5 times higher than WT RS047. Moreover, the saturated fatty acid (SFA) contents in cell membrane and the cell volume significantly increased in the RS047-wl. The combined transcriptomic, metabolomic, and proteomics analysis results showed a significant enhancement of cell wall and membrane synthesis ability in the RS047-wl. In conclusion, one of the main factors contributing to the improved high temperature resistance of RS047-wl was its enhanced ability to synthesize cell wall and membrane, which helped maintain normal cell morphology. Developing a high-temperature-resistant strain and understanding its mechanism enables it to adapt to high temperatures. This lays the groundwork for its future development and application.

Germacrane Sesquiterpene Dilactones from Mikania micrantha and Their Antibacterial and Cytotoxic Activity.

Four new germacrane sesquiterpene dilactones, 2ß-hydroxyl-11ß,13-dihydrodeoxymikanolide (1), 3ß-hydroxyl-11ß,13-dihydrodeoxymikanolide (2), 1α,3ß-dihydroxy-4,9-germacradiene-12,8:15,6-diolide (3), and (11ß,13-dihydrodeoxymikanolide-13-yl)-adenine (4), together with five known ones (5-9) were isolated from the aerial parts of Mikania micrantha. Their structures were elucidated on the basis of extensive spectroscopic analysis. Compound 4 is featured with an adenine moiety in the molecule, which is the first nitrogen-containing sesquiterpenoid so far isolated from this plant species. These compounds were evaluated for their in vitro antibacterial activity against four Gram-(+) bacteria of Staphyloccocus aureus (SA), methicillin-resistant Staphylococcus aureus (MRSA), Bacillus cereus (BC) and Curtobacterium. flaccumfaciens (CF), and three Gram-(-) bacteria of Escherichia coli (EC), Salmonella. typhimurium (SA), and Pseudomonas Solanacearum (PS). Compounds 4 and 7-9 were found to show strong in vitro antibacterial activity toward all the tested bacteria with the MIC values ranging from 1.56 to 12.5 µg/mL. Notably, compounds 4 and 9 showed significant antibacterial activity against the drug-resistant bacterium of MRSA with MIC value 6.25 µg/mL, which was close to reference compound vancomycin (MIC 3.125 µg/mL). Compounds 4 and 7-9 were further revealed to show in vitro cytotoxic activity toward human tumor A549, HepG2, MCF-7, and HeLa cell lines, with IC50 values ranging from 8.97 to 27.39 µM. No antibacterial and cytotoxic activity were displayed for the other compounds. The present research provided new data to support that M. micrantha is rich in structurally diverse bioactive compounds worthy of further development for pharmaceutical applications and for crop protection in agricultural fields.

Influence of circulation types on temporal and spatial variations of ozone in Beijing.

This study analyzes the impact of circulation types (CTs) on ozone (O3) pollution in Beijing. The easterly high-pressure (SWW) circulation occurred most frequently (30%; 276 day), followed by northwesterly high-pressure (AN) circulation (24.3%; 224 day). The SWW type had the highest O3 anomaly of +17.28 µg/m3, which was caused by excellent photochemical reactions, poor diffusion ability and regional transport. Due to the higher humidity and precipitation in the low-pressure type (C), the O3 increase (+8.02 µg/m3) was less than that in the SWW type. Good diffusion/wet deposition and weak formation ability contributed to O3 decrease in AN (-12.54 µg/m3) and northerly high-pressure (ESN) CTs (-12.26 µg/m3). The intra-area transport of O3 was significant in polluted circulations (SWW- and C-CTs). In addition, higher temperature, radiation and less rainfall also contributed to higher O3 in northern Beijing under the SWW type. For the clean CTs (AN and ESN CTs), precursor amount and intra-area transport played a dominant role in O3 distribution. Under the northeasterly low-pressure CT, better formation conditions and higher precursor amount combined with the intra-area southerly transport to cause higher O3 values in the south than in the north. The higher O3 in the northwestern area under the northeasterly high-pressure type was influenced by weaker titration loss and high O3 concentration in previous day. Annual variation in the CTs contributed up to 86.1% of the annual variation in O3. About 78%-83% of the diurnal variation in O3 resulted from local meteorological factors.

[Application of Mecapegfilgrastim for Peripheral Blood Hematopoietic Stem Cell Mobilization in Patients With Hematologic Neoplasms and Analysis of Predictors for Poor Mobilization].

Objective: To evaluate the efficacy of applying mecapegfilgrastim for peripheral blood hematopoietic stem cell (PBSC) mobilization in patients with hematologic neoplasms, and to investigate the influencing factors of PBSC collection. Methods: Patients who underwent PBSC mobilization in the Department of Hematology, Mianyang Central Hospital between April 2016 and May 2022 were retrospectively analyzed. The CD34 + cell collection results of two groups, the mecapegfilgrastim group ( n=28), or the PEG group, and the recombinant human granulocyte colony-stimulating factor (rhG-CSF) group ( n=30), were compared, and the influencing factors of collection failure were analyzed. Results: The success rates of CD34 + cells collection in the PEG group and the rhG-CSF group were 75.0% and 63.3%, respectively ( P>0.05). The median CD34 + cell counts were 3.37×10 6/kg and 2.68×10 6/kg, respectively, showing no significant difference. After combined mobilization with plerixafor, the median counts of CD34 + cells collected in the PEG group and rhG-CSF group were 4.23×10 6/kg and 3.26×10 6/kg, respectively, showing no significant difference ( P>0.05). There was no significant difference in hematopoietic system reconstruction and infections between the two groups ( P>0.05). Multivariate analysis found non-plasma cell disease (odds ratio [ OR]=19.697, 95% confidence interval [ CI] : 1.501-258.537, P=0.023), anemia before collection ( OR=18.571, 95% CI: 1.354-254.775, P=0.029) and white blood cell count before collection under 32×10 9 L -1 ( OR=85.903, 95% CI: 4.947-1491.807, P=0.002) to be independent risk factors for PBSC collection failure. Conclusion: The effect of PBSC mobilization with mecapegfilgrastim was comparable to that of rhG-CSF in patients with hematologic neoplasms. Furthermore, combined mobilization with plerixafor was feasible and effective. Patients with leukemia or lymphoma, anemia, and WBC<32×10 9 L -1 before stem cell collection have a high probability of PBSC collection failure.

Quantitative Evaluation on the Degradation Process of the Pulmonary Surfactant Monolayer When Exposed to Low-Level Ozone of Ambient Environment.

Ozone is a potent environmental oxidant with high chemical reactivity and is present in the ambient environment at a low level of a few tens of ppb. However, only limited information is known about low-level ozone's influence on the respiratory system. In the present study, we systematically investigated the degradation of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), which is one of the major components of the pulmonary surfactant (PS), enabling breath function of the lung exposed to low ambient-level ozone (40 ± 10 ppb). Using the liquid chromatography-mass spectrometry technique combined with the Langmuir-Blodgett approach, we first tracked the degradation process of POPC molecules by determining the degradation products during exposure to the ambient environment. As a result, we found that the POPC molecules can be readily degraded from the C═C moiety in 45 min, yielding an aldehyde-type product of 1-palmitoyl-2-(9'-oxo-nonanoyl)-sn-glycero-3-phosphocholine (POnPC) and a trace amount of an acid-type one of 1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine (PAzPC), as well as a pair of secondary ozonide (SOZ) isomers. Furthermore, with prolonged exposure, the SOZ stayed constant but the yield of PAzPC significantly increased with the decrease in POnPC. The low-level ozone-induced oxidation mechanisms for unsaturated lipids are discussed based on the quantitative analyses of these experimental observations. The present results demonstrate that the ground-level ozone is strong enough to induce dramatic oxidation damage to the unsaturated lipids of the PS. These oxidized species may trigger the lung's inflammatory response and be used as biomarkers for oxidative stress and inflammation.

Recognition and Health Impacts of Organic Pollutants with Significantly Different Proportions in the Gas Phase and Size-Fractionated Particulate Phase in Ambient Air.

The distributions of organic pollutants in the gas phase and size-fractionated particle phases can largely affect human health risks posed by them. Gas-particle partitioning and particle-size distributions of some known pollutants have been investigated. However, the pollutants which are more likely to enter the human body and cause strong adverse effects may be neglected. In this study, a nontargeted screening approach combining comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry and chemometrics was developed. Eighty-eight compounds with markedly different proportions in the gas phase and PM1, as well as 50 contaminants with significant differences in PM1 and particles with diameters of 1-2.5 µm, were identified. Of these compounds, 18 were found in the air for the first time. There were obvious discrepancies between the measured and predicted gas-particle partitioning coefficients for some pollutants, suggesting unexpected environmental fates and health risks. The human daily intakes through inhalation and dermal exposure to these pollutants were estimated with the International Commission on Radiological Protection deposition model and transdermal permeability model. A risk-based prioritization was performed. The results indicated that adverse effects posed by 9H-fluoren-9-one, 2-ethylhexyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, p-cumenol, 2,4-diisocyanato-1-methyl-benzene, bis(2-ethylhexyl) phthalate, perylene, (E)-cinnamaldehyde, 4-methyl-2-nitro-phenol, benzoic acid, and bis(2-methylpropyl) ester hexanedioic acid in ambient air may be more severe than those posed by conventionally monitored pollutants. The findings would facilitate raising concerns about these pollutants before they cause further severe and widespread impacts.

Screening of ToxCast Chemicals Responsible for Human Adverse Outcomes with Exposure to Ambient Air.

Air pollution poses a major threat to global public health. Although there have been a few investigations into the relationships between organic pollutants and adverse outcomes, the responsible components and molecular mechanisms may be ignored. In this study, a suspect screening method combining comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOF MS) with the Toxicity Forecaster (ToxCast) database was applied to analyze complex hydrophobic compounds in ambient air and prospectively figure out toxicologically significant compounds. Seventy-six ToxCast compounds were screened, including seven pollutants receiving less attention and five chemicals never published in the air previously. Given the concentrations, bioactivities, as well as absorption, distribution, metabolism, and excretion properties in vivo, 29 contaminants were assigned high priority since they had active biological effects in the vascular, lung, liver, kidney, prostate, and bone tissues. Phenotypic linkages of key pollutants to potential mechanistic pathways were explored by systems toxicology. A total of 267 chemical-effect pathways involving 29 toxicants and 31 molecular targets were mapped in bipartite network, in which 12 key pathogenic pathways were clarified, which not only provided evidence supporting the previous hypothesis but also provided new insights into the molecular targets. The results would facilitate the development of pollutant priority control, population intervention, and clinical therapeutic strategies so as to substantially reduce human health hazards induced by urban air.

Concentrations, Compound Profiles, and Possible Sources of Organic UV Filters in Human Milk in China.

Ultraviolet (UV) filters are of great concern due to their wide occurrence, bioaccumulation, and toxicity. Little is known about human exposure to UV filters. A total of 3467 individual human milk samples from 24 Chinese provinces were collected during 2017-2019. The concentrations of 12 UV filters in 100 pooled milk samples were determined. The total UV filter concentration was 78-846 (mean 235 ± 120) ng/g lipid weight. The highest and lowest total mean concentrations were for samples from Qinghai and Sichuan provinces, respectively. A significant positive correlation was found between UV radiation levels and UV concentrations in the samples. The dominant UV filters were 2-(2-hydroxy-5-methylphenyl) benzotriazole (UV-P) and ethylhexyl methoxycinnamate (EHMC), which contributed means of 32 and 22%, respectively, to the total concentrations. Plastic products and sunscreens were probably the sources of UV-P and EHMC in the human milk from China, respectively. The mean 2-(3,5-di-tert-amyl-2-hydroxyphenyl) benzotriazole (UV-328) concentration was 2.6 ± 2.6 ng/g lipid weight. The UV filter profiles were similar to profiles for samples from Japan, the Philippines, and Switzerland but not for samples from Korea and Vietnam. The estimated daily UV filter intake for breastfed infants was below the corresponding reference dose. This was the first large-scale study of UV filters in human milk and will help assess the risks posed.

Screening organic contaminants in soil by two-dimensional gas chromatography high-resolution time-of-flight mass spectrometry: A non-target analysis strategy and contaminated area case study.

Thousands of organic substances that are used in industrial applications ultimately enter the soil and may negatively affect human health. Limited numbers of target pollutants are usually monitored in environmental media because of analytical limitations. In this study, a non-target screening method for quickly analyzing multiple soil samples from a contaminated area (a chemical industry park) by two-dimensional gas chromatography high-resolution time-of-flight mass spectrometry was developed. The types of compounds present in the soil samples were preliminarily analyzed through data simplification and visual assessment. A total of 81 organic compounds with detection frequencies ≥40% in the samples from the chemical industry park were selected for identification, including 38 PAHs, 26 oxygenated organic compounds, eight N-containing compounds, and nine other compounds. Potential sources of the organic compounds in the industrial park were investigated. Some pharmaceutical and organic synthetic intermediates in the soil were affected by nearby chemical plants. After assessing the relative abundances and detection frequencies, 36 pollutants that may pose potential risks to the environment were preliminarily identified. The results of the study were helpful for assessing environmental risks around Yangkou industrial park and they will be helpful when assessing risks in other contaminated areas.