Ambient particulates of Shanghai with 5-stage particle sizes were firstly determined in spring, 2017. The particles’ mass concentrations were mainly observed in fine particle matter (PM
1.1
) and ...coarse particles (diameter > 7.0 μm). Water-soluble ionic contents were also more distributed in PM
1.1
with the great contents of secondary particles (NO
3
−
, SO
4
2−
, and NH
4
+
). Higher ratios of NO
2
/SO
2
and NO
3
−
/SO
4
2−
indicated that the vehicle emissions might be made more greater contribution rather than coal combustions to the fine particles. Crustal enrichment factors (EFcs) of trace elements (V, Cr, Ni, Zn, As, Se, Rb, Cd, Pb, and Bi) in PM
1.1
in that called slight air pollution events were always higher than those in that called severe air pollution events and EFcs of Se were up to 2.5 × 10
4
, while EFcs of Pb, Bi, and Cd were over 100. Based on kinds of elemental ratios in PM
1.1
and PM
1.1–2.0
, atmospheric pollutants in Shanghai might be mainly from coal and oil combustions, diesel, and gasoline vehicles. Air masses backward trajectories also showed that the air masses from the northern part of China were one important air pollutant origins, but other ones might be the local sources, such as traffic and industries. Based on carcinogenic risk analysis of PM
2.0
, it was considerable that 12–60 children and 37–87 adults among millions of people living in Shanghai might be attacked by cancer during their lifetime. Moreover, the great carcinogenic risk was also observed according to the high concentrations of elemental Cr and As in PM
1.1
.
Due to the COVID-19 pandemic, Bangladesh government took the measure like partial lockdown (PL) and complete lockdown (CL) to curb the spread. These measures gave a chance for environmental ...restoration. In this study, street dust samples were collected during PL and CL from four main urban land use categories in Dhaka city, such as industrial area (IA), commercial area (CA), public facilities area (PFA), and residential area (RA). Ten potentially toxic elements (Cr, Mn, Zn, Fe, Pb, Cu, Co, Ni, As, and Cd) in fine street dust particles (diameter < 20 μm) were determined following aqua-regia digestion and measured by inductively coupled plasma mass spectrometry (ICP-MS) to evaluate distribution, pollution sources, and potential risks to ecological systems and human health. Results showed that during PL, the concentrations of toxic elements in the dust were higher than that of CL. Cd and Fe were lowest and highest in concentration with 1.56 to 41,970 µg/g and 0.82 to 39,330 µg/g in partial and complete lockdown period respectively. All toxic elements were detected at high levels above background values where Fe with the highest and Cd with lowest concentrations, respectively. By land use, the levels of toxic elements pollution followed IA > PFA > RA > CA. Correlation analysis (CA), principal component analysis (PCA), and hierarchal cluster analysis (HCA) revealed that the sources of these analyzed toxic elements were mainly from anthropogenic which are related to industrial and vehicular or traffic emissions. Enrichment factor (EF), geoaccumulation index (
I
geo
), contamination factor (CF), and pollution load index (PLI) also suggested that the dust was more polluted during PL. Exposure of toxic elements to human was mainly via skin contact followed by ingestion and inhalation. Hazard quotient (HQ) values were < 1 except for Mn through dermal contact at all sites during partial and complete lockdown, similar to hazard index (HI), while Cr further showed high non-carcinogenic risks to children. Generally, children HI values were about 5–6 times higher than those of adults, suggesting a greater vulnerability of children to the health concerns caused by toxic elements in street dust. Carcinogenic risk (CR) values via ingestion pathway indicated all elements (except Pb) had significant health effect, while CR value by inhalation results showed no significant health effect. Cumulative carcinogenic risk (CCR) value had significant health effect except Pb in all land use categories. CCR values decreased during CL and reached at acceptable limit for most of the cases. This research provides a message to the local governments and environmental authorities to have a complete assessment of toxic elements in the street dust of Dhaka megacity in order to assuring public health safety and ecological sustainability.
Sorghum halepense
is a perennial invasive weed causing great harm worldwide, including various regions on Hainan island. In this study, using two approaches, we examined plant-soil feedback of ...different
S. halepense
populations. In the first, rhizosphere soil of
S. halepense
from the field was either sterilized or not to study the role of soil biota on
S. halepense
growth. In the second, we first let
S. halepense
plants condition the soil, and then regrow plants on these conditioned soil to study the role of overall changes in soil properties in plant-soil feedback. Sterilization increased the growth of
S. halepense
, indicating that soil biota inhibited the growth of
S. halepense
. Soil biota from some populations inhibited the growth of
S. halepense
more than that from others. In most cases, the relative response of a
S. halepense
population when associated with its own soil vs. when associated with other soils was similar to the relative response of other populations across the same soils. In the second approach, the effect of conditioning on most soil chemical properties were not different among populations. The interactive effect of conditioning population and replanting population on plant biomass was not significant, indicating that the performance of different
S. halepense
populations did not depend on the population of
S. halepense
that conditioned the soil. These results indicate that on Hainan island,
S. halepense
can outburst and proliferate despite negative feedback with soil biota, and populations of
S. halepense
differ little in their interactions with soil.
Gas spark switches had been applied extensively in the field of pulse power technology on account of the advantages of a simple structure, short breakdown time, and high through-current capability. ...This paper investigates the streamer breakdown process in a two-electrode switch in a nitrogen environment under atmospheric pressure using a numerical method. First, a two-dimensional fluid simulation was carried out for the streamer generated under the negative and positive trigger voltages, and the difference in the breakdown mechanism in the two modes was analyzed. The study showed that when a negative trigger voltage is applied to the rod electrode, a negative streamer from the cathode to the anode will first be formed, and then a positive streamer from the anode to the cathode will be formed. When a positive trigger voltage is applied to the rod electrode, the streamer propagation mechanism is significantly different from that obtained when a negative voltage is applied. In this case, the breakdown mode is a cathode-directed streamer. Finally, we investigated the effect of circuit parameters on the breakdown process. The time scale of breakdown varies greatly with the capacitance. The significant difference in the breakdown process may come from the charging process of the capacitor. The larger the capacitance is, the slower the charging process will be.
Per- and Polyfluoroalkyl Substances (PFAS) and microplastics (MPs) removal is one of the main technical measures in these emerging pollutant control and MPs can sorb PFAS acting as carriers. In order ...to explore the sorption process of polyethylene (PE MPs) for different PFAS, Grand Canonical Monte Carlo and molecular dynamics simulation was used. Seven commonly found PFAS compounds including PFNA (Perfluorononanoic acid), PFHxS (Perfluorohexanesulphonic acid), PFHxA (Perfluorohexanoic acid), PFDA (Perfluorodecanoic acid), PFOS (Perfluorooctanesulfonic acid), PFBS (Perfluorobutanesulfonic acid) and Perfluorooctanoic acid (PFOA) were selected. The sorption on PE MPs was based on fixed loading and the sorption (PE MPs+PFAS) average total energy for all simulation steps followed PFHxA (−29.17 kcal/mol) < PFBS (−52.71 kcal/mol) < PFOA (−57.12 kcal/mol) < PFNA (−70.58 kcal/mol) < PFDA (−78.27 kcal/mol) < PFHxS (−80.06 kcal/mol) < PFOS (−102.30 kcal/mol). However, the binding/interaction energies followed PFHxS > PFOS > PFNA > PFDA > PFOA > PFBS > PFHxA. The MD simulation was carried out under NVT ensemble at 298 K, the thermodynamic states and relaxation pretreatment procedures were then examined quantitatively by radial distribution function, X-ray scattering, relative concentration profile, mean square displacement and space time correlation function. The results show that effective sorption of PFAS molecule by PE MPs involves hydrogen or chemical bonding as well non-bond energy such as Van der Waals (VdW), electrostatic and intramolecular energies. The cell volume did not change during single and multicomponent sorption while the sorption density increased about threefold the single component (0.36 g/cm
3
), suggesting that as the pollutant number increased the sorption capacity increased. This study showed that PE MPs can used for single and multicomponent sorption of PFASs effectively and also provided theoretical support for our knowledge of the sorption mechanism at the molecular level, which will help in better understanding of PFAS removal by MPs.
Pollen allergens, widely present in the atmosphere, are the main cause of seasonal respiratory diseases that affect millions of people worldwide. Although previous studies have reported that nitrogen ...dioxide (NO2) and ozone (O3) promote pollen allergy, the specific biological processes and underlying mechanisms remain less understood. In this study, Platanus pollen grains were exposed to gaseous pollutants (NO2 and O3). We employed environmental electron microscopy, flow cytometry, western blot assay, enzyme-linked immunoassay, ultraviolet absorption spectrometry, circular dichroism, and protein mass spectrometry to characterise the subpollen particles (SPPs) released from pollen grains. Furthermore, we determined the immunogenicity and pathogenicity induced by Platanus pollen allergen a 3 (Pla a 3). Our results demonstrated that NO2 and O3 could damage the pollen cell membranes in SPPs and increase the amount of Pla a 3 allergen released into the atmosphere. Additionally, NO2 and O3 altered the structure of Pla a3 protein through nitrification and oxidation, which not only enhanced the immunogenicity of allergens but also increased the stability of the protein. In vivo analysis using an animal model indicated that NO2 and O3 greatly aggravated pollen-induced pneumonia. Thus, our study provides guidance for the prevention of pollen allergic diseases.
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•Allergenic protein (including Pla a3) found in subpollen particles (SPPs).•NO2 and O3 could damage the pollen cell membrane.•NO2 and O3 could change the structure of Pla a3 protein and aggravate pollen allergic reaction.
Group 1 protease allergens that persist in fecal particles from house dust mites (HDM) are the prevalent indoor aeroallergens and the primary triggers of dust mite allergy. Consequently, it is vital ...to discover a secure, efficient, affordable, and eco-friendly inhibitor to restrain these allergens. Herein, an assessment on the suppression of allergens Der f 1 and Der p 1 (predominant Group 1 allergens) with todomatsu oil derived from the remnants of Abies sachalinensis was performed using enzyme-linked immunosorbent assay (ELISA), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and molecular docking analysis in silico. The results demonstrated that todomatsu oil effectively suppresses allergens Der f 1 and Der p 1 by lowering their allergen contents, and the decline rate rises with increasing todomatsu oil concentration. The formation of alkyl hydrophobic interactions, pi-sigma bonds, and hydrogen bonds have been observed between oil ingredients and allergens Der f 1 and Der p 1. Intriguingly, the majority of oil ingredients prefer to dock on hydrophobic amino acids. Additionally, oil ingredients docked to the cysteine protease site on Der f 1 or IgG epitope on Der p 1 were discovered. Notably, the binding affinity (BA) score and inhibition constant (Ki) revealed that bornyl acetate, the component with the maximum relative proportion in todomatsu oil, is included in the top five ingredients with the best inhibition effectiveness. As a result, todomatsu oil has been identified as an efficient inhibitor against Group 1 HDM allergens and a viable measure to improve indoor air quality.
Pyrrolizidine alkaloids (PAs) are among the most hepatotoxic natural compounds that are widely distributed throughout the world. Most PAs are metabolically activated to trigger toxicity. Exposure to ...herbal medicine containing PAs and food supplements contaminated by PAs is considered to be one of the two main causes of hepatic sinusoidal obstruction syndrome (HSOS), which is a rare hepatic vascular disease with a high mortality rate. PAs-induced HSOS cases have been reported worldwide. However, there is no clinically effective therapy for PAs-induced HSOS, which is partially because the toxic mechanism is not fully understood. This review focuses on updating the information on the metabolism and the molecular mechanisms of PAs hepatotoxicity, including oxidative stress, apoptosis, and dysfunction of bile acid metabolism, and their interactions.
Immune checkpoint inhibitors were used for patients with advanced non-small cell lung cancer (NSCLC) more and more frequently and the effects were thrilling. Toripalimab as a new immune checkpoint ...inhibitor has been shown to be effective in patients with advanced NSCLC. However, data regarding the safety and feasibility of surgical resection after treatment with toripalimab for NSCLC remain scarce. Here, we present a case with locally advanced NSCLC that received video-assisted thoracic surgery (VATS) lobectomy after treatment with toripalimab in combination with chemotherapy.
A 62-year-old male patient with a history of coronary artery stenting operation for two times was found a 3.4 × 3.2 cm cavity mass in the upper lobe of the left lung and enlarged left hilar and mediastinal lymph nodes. Pathological results identified squamous cell carcinoma. The patient was diagnosed with a locally advanced NSCLC and received VATS left upper lobectomy and lymph node dissection after neoadjuvant chemotherapy plus toripalimab for 3 cycles. The postoperative pathological results showed complete tumor remission. Short-term follow-up results were excellent, and long-term results remain to be revealed.
Our preliminary results showed that the use of neoadjuvant toripalimab and chemotherapy for the locally advanced NSCLC before surgical resection is safe and feasible.
Ozone (O3) and nitrogen dioxide (NO2) are thought to play primary roles in aggravating air pollution-induced health problems. However, the effects of joint O3/NO2 on the allergenicity of pollen ...allergens are unclear. Humulus japonicus pollen allergen 1 (Hum j1) is a profilin protein that causes widespread pollinosis in eastern Asia. In order to study the effects of combined O3/NO2 on the allergenicity of Hum j1, tandem six-histidine peptide tag (His6)-fused recombinant Hum j1 (rHum j1) was expressed in a prokaryotic system and purified through His6 affinity chromatography. The purified rHum j1 was used to immunize SD rats. Rat sera with high titers of IgG and IgE antibodies against rHum j1 were used for allergenicity quantification. The rHum j1 was exposed to O3/NO2, and changes in allergenicity of the exposed rHum j1 were assayed using the immunized rat antibodies. Tandem LC-MS/LC (liquid chromatography-mass spectrometer/liquid chromatography spectrometer) chromatography and UV and circular dichroism (CD) spectroscopy were used to study the structural changes in rHum j1. Our data demonstrated that a novel disulfide bond between the sulfhydryl groups of two neighboring cysteine molecules was formed after the rHum j1 exposure to joint O3/NO2, and therefore IgE-binding affinity was increased and the allergenicity was reinforced. Our results provided clues to elucidate the mechanism behind air pollution-induced increase in pollinosis prevalence.
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•High titers of IgG and IgE antibodies induced by Humulus japonicus pollen allergen 1 (Hum j1) were prepared.•Combined O3/NO2 stabilizes allergens and increases their allergenicity.
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