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Influenza A viruses (IAVs) pose a persistent potential threat to human health because of the spillover from avian and swine infections. Extensive surveillance was performed in 12 cities of Guangxi, China, during 2018 and 2023. A total of 2,540 samples (including 2,353 nasal swabs and 187 lung tissues) were collected from 18 pig farms with outbreaks of respiratory disease. From these, 192 IAV-positive samples and 19 genomic sequences were obtained. We found that the H1 and H3 swine influenza A viruses (swIAVs) of multiple lineages and genotypes have continued to co-cirulate during that time in this region. Genomic analysis revealed the Eurasian avian-like H1N1 swIAVs (G4) still remained predominant in pig populations. Strikingly, the novel multiple H3N2 genotypes were found to have been generated through repeated introduction of the early H3N2 North American triple reassortant viruses (TR H3N2 lineage) that emerged in USA and Canada in 1998 and 2005, respectivley. Notably, when the matrix gene segment derived from H9N2 avian influenza virus was introduced into endemic swIAVs, this produced a novel quadruple reassortant H1N2 swIAV that could pose a potential risk for zoonotic infection.

The levels of carbonyl compounds in Shanghai ambient air were measured in five periods from January 2007 to October 2007 (covering winter, high-air-pollution days, spring, summer and autumn). A total of 114 samples were collected and eighteen carbonyls were identified. Formaldehyde, acetaldehyde and acetone were the most abundant carbonyls and their mean concentrations of 19.40 ± 12.00, 15.92 ± 12.07 and 11.86 ± 7.04 μg m⁻³ respectively, in the daytime for five sampling periods. Formaldehyde and acetaldehyde showed similar diurnal profiles with peak mixing ratios in the morning and early afternoon during the daytime. Their mean concentrations were highest in summer and lowest in winter. Acetone showed reversed seasonal variation. The high molecular weight (HMW, >=C5) carbonyls also showed obvious diurnal variations with higher concentrations in the daytime in summer and autumn, while they were all not detected in winter. Formaldehyde and acetaldehyde played an important role in removing OH radicals in the atmosphere, but the contribution of acetone was below 1%. The carbonyls levels in high-air-pollution days were reported. More carbonyl species with higher concentrations were found in high-air-pollution days than in spring. These carbonyls were transported with other pollutants from north and northwest in March 27 to April 2, 2007 and then mixed with local sources. Comparing with Beijing and Guangzhou, the concentrations of formaldehyde and acetaldehyde in Shanghai were the highest, which indicated that the air pollution in Shanghai was even worse than expected.

Polychlorinated biphenyl (PCB) concentrations, profiles, and possible sources were determined in the atmosphere of Guangzhou, the largest city in south China. [summation operator]PCB concentrations ranged from 160 to 2720 pg/m³, which is comparable with values found by similar studies in North America, Europe, and Asia. The highest PCB concentrations were found in the old industrial district, suggesting it to be the principal emission source. The most important PCB homologue group was tetra-PCB, followed by tri- and penta-PCB. The PCBs' homologue composition differs from that found in Chinese transformer oils: Chinese PCB products (no. 1 PCB and no. 2 PCB), Aroclor1242, and Aroclor1254. However, it is similar in composition to that found in sediments and soils subjected to arbitrary disposal of used electronic appliances in this region. Our results suggest that volatilization from PCB-contaminated soils in the old urban center may be the major source of PCBs in the atmosphere of Guangzhou. Additional studies will be required to characterize the geochemical cycles of PCBs from the contaminated environmental “hot spots” during the typical subtropical climate conditions in the study regions.

Eight humic acid (HA) fractions obtained by repetitive base extraction of a peat soil were characterized in terms of chemical compositions, functionalities, and molecular sizes using an elemental analyzer, infrared spectrometry (IR), solid-state ^sup 13^C-nuclear magnetic resonance spectrometry (^sup 13^C-NMR), and high performance size-exclusion chromatography (HPSEC). Large variations in chemical, functional, and molecular properties were observed among the eight humic fractions. The elemental analysis data showed that, from the first (Fr1) to the eighth fraction (Fr8), the O/C atomic ratio decreased from 0.52 to 0.36 whereas the H/C atomic ratio increased from 1.1 to 1.5. The measured average apparent molecular size (M^sub w^) increases from 7.7 to 22.1 kDa as a function of the extent of extraction. Carbon-13 NMR and FTIR spectra of the fractions indicated that the contents of oxygen-containing and aromatic functional groups decreased and the contents of aliphatic groups increased from Fr1 to Fr8. The results suggested that two subunits of HAS might exist: an aliphatic subunit having larger apparent M^sub w^, and an aromatic subunit having smaller apparent M^sub w^. We proposed that each of the eight HA fractions is a mixture of these two subunits.

This study examines the effect of soil organic matter heterogeneity on equilibrium sorption and desorption of phenanthrene, naphthalene, 1,3,5‐trichlorobenzene (1,3,5‐TCB), and 1,2‐dichlorobenzene (1,2‐DCB) by soils and sediments. Two estuary sediments, a Pahokee peat (PP; Euic, hyperthermic Lithic Haplosaprist), and two subsamples (base‐ and acid‐treated peat [TP] and acid‐treated peat [FP]) of the peat were used as the sorbents. The contents of black carbon particles were quantified with a chemical extraction method. Petrographical examinations revealed the presence of the condensed soil and sediment organic matter (SOM) in Pahokee peat. The Freundlich isotherm model in two different forms was used to fit both sorption and desorption data. The results show that the sorption and desorption isotherms are generally nonlinear and that the apparent sorption–desorption hysteresis is present for phenanthrene and TCB. Detailed analysis of sorption data for the tested sorbent–sorbate systems indicates that black carbon is probably responsible for sorption isotherm nonlinearity for the two sediments, whereas the humic substances and kerogen may play the dominant role in nonlinear sorption by the peat. This investigation suggests that the microporosity of SOM is important for the hydrophobic organic contaminant (HOC) sorption capacity on the peat.

Sorption of organic pollutants by subsurface materials has been found to not only correlate with the total organic carbon (TOC) content, but also depend on the types of soil and sediment organic matter (SOM). Characterization of geochemically heterogeneous SOM is key to elucidating sorption mechanisms and predicting pollutant transport in ground water systems. In this study, kerogen, a nonextractable organic material, was isolated with an acid demineralization procedure from a sandy aquifer material (Borden, Ontario, Canada) having a TOC content of approximately 0.021% (w/w). Petrographical examinations reveal that the kerogen has three major types of macerals including bituminite (Kerogen Type I and II), vitrinite (Type III), and fusinite (Type IV or charred kerogen). The solid‐state 13C nuclear magnetic resonance (NMR) spectrum shows two dominant peaks, aliphatic and aromatic carbons, for the isolated material. Sorption isotherms measured using phenanthrene, naphthalene, 1,3,5‐trichlorobenzene (TCB), and 1,2‐dichlorobenzene (DCB) as sorbates showed that both the isolated kerogen and the original sand exhibited nonlinear sorption and that the phenanthrene and TCB isotherms measured for the kerogen material are more nonlinear than the respective isotherms for the original sand. The single‐point organic carbon–normalized sorption capacity measured for the isolated kerogen can be several times greater than that measured for the original sand for a given sorbate. The study suggests that kerogen plays a major role in overall sorption isotherm nonlinearity and could yield higher‐than‐predicted sorption capacities for the subsurface material even though the content of this organic material is very low.

Background, aim, and scope Carbonyl compounds have been paid more and more attention because some carbonyl species have been proven to be carcinogenic or a risk for human health. Plant leaves are both an important emission source and an important sink of carbonyl compounds. But the research on carbonyl compounds from plant leaves is very scarce. In order to make an approach to the emission mechanism of plant leaves, a new method was established to extract carbonyl compounds from fresh plant leaves. Materials, methods, and results The procedure combining derivatization with ultrasonication was developed for the fast extraction of carbonyl compounds from tree leaves. Fresh leaves (< 0.01 g) were minced and ultrasonicated in acidic 2,4-dinitrophenylhydrazine (DNPH)-acetonitrile solution for 30 min and then holding 30 min to allow aldehydes and ketones in leaves to react completely with DNPH. Conclusions The extraction process was performed under room temperature and only took 60 min. The advantages of this method were very little sample preparation, requiring short treatment time and usual equipment. Four greening trees, i.e., camphor tree ( Cinnamomum camphora ), sweet olive ( Osmanthus fragrans ), cedar ( Cedrus deodara ), and dawn redwood ( Metasequoia glyptostroboides ), were selected and extracted by this method. Seven carbonyl compounds, including formaldehyde, acetaldehyde, acetone, acrolein, p -tolualdehyde, m / o -tolualdehyde, and hexaldehyde were determined and quantified. The most common carbonyl species of the four tree leaves were formaldehyde, acrolein, and m / o -tolualdehyde. They accounted for 67.3% in cedar, 50.8% in sweet olive, 45.8% in dawn redwood, and 44.6% in camphor tree, respectively. Camphor tree had the highest leaf level of m / o -tolualdehyde with 15.0 ± 3.4 µg g −1 (fresh leaf weight), which indicated that camphor tree may be a bioindicator of the level of tolualdehyde or xylene in the atmosphere. By analyzing carbonyl compounds from different tree leaves, it is not only helpful for further studying the relationship between sink and emission of carbonyls from plants, but also helpful for exploring optimum plant population in urban greening.

The overall goal of the present study was to establish correlations between organic pollutant sorption and physicochemical properties of kerogen materials. Three coal samples, each representing a typical kerogen type, were used as the starting materials. A thermal technique was employed to treat the kerogen materials under seven different temperatures ranging from 200 to 500°C to simulate different diagenetic history. These samples were systematically characterized for their chemical compositions, functionalities, physical rigidity, and optical properties. The results showed that the chemical, spectroscopic, and optical microscopic properties of each kerogen series changed consistently as a function of treatment temperature or kerogen maturation. The oxygen-to-carbon atomic ratio decreased from 0.29, 0.12, and 0.07 for the original lignite (XF0), fusinite (HZ0), and lopinite (LP0) samples, respectively, to 0.07, 0.06, and 0.04 for XF7, HZ7, and LP7, respectively, that underwent the highest temperature treatment. The hydrogen-to-carbon atomic ratio exhibited similar reducing trend, which is consistent with the aromaticity increasing from 45 to 58% of the original samples to 76 to 81% of highly mature samples. Under the fluorescence microscope, the organic matrix changed from yellow (original lignite sample) and red-brown (original lopinite sample) to colorless for the samples of higher maturation. The measured reflecting index increased from the original samples to the highly mature samples. Moreover, the original and the slightly matured samples exhibited very different chemical compositions and structural units among the three types due to the difference in their source materials. As the kerogen maturation increased, such differences decreased, indicating highly mature kerogen became homogenized regardless of the source material.

Phenanthrene and naphthalene sorption isotherms were measured for three different series of kerogen materials using completely mixed batch reactors. Sorption isotherms were nonlinear for each sorbate-sorbent system, and the Freundlich isotherm equation fit the sorption data well. The Freundlich isotherm linearity parameter n ranged from 0.192 to 0.729 for phenanthrene and from 0.389 to 0.731 for naphthalene. The n values correlated linearly with rigidity and aromaticity of the kerogen matrix, but the single-point, organic carbon-normalized distribution coefficients varied dramatically among the tested sorbents. A dual-mode sorption equation consisting of a linear partitioning domain and a Langmuir adsorption domain adequately quantified the overall sorption equilibrium for each sorbent-sorbate system. Both models fit the data well, with r2 values of 0.965 to 0.996 for the Freundlich model and 0.963 to 0.997 for the dual-mode model for the phenanthrene sorption isotherms. The dual-mode model fitting results showed that as the rigidity and aromaticity of the kerogen matrix increased, the contribution of the linear partitioning domain to the overall sorption equilibrium decreased, whereas the contribution of the Langmuir adsorption domain increased. The present study suggested that kerogen materials found in soils and sediments should not be treated as a single, unified, carbonaceous sorbent phase.

Eight humic acid (HA) fractions obtained by repetitive base extraction of a peat soil were characterized in terms of chemical compositions, functionalities, and molecular sizes using an elemental analyzer, infrared spectrometry (IR), solid‐state 13C‐nuclear magnetic resonance spectrometry (13C‐NMR), and high performance size‐exclusion chromatography (HPSEC). Large variations in chemical, functional, and molecular properties were observed among the eight humic fractions. The elemental analysis data showed that, from the first (Fr1) to the eighth fraction (Fr8), the O/C atomic ratio decreased from 0.52 to 0.36 whereas the H/C atomic ratio increased from 1.1 to 1.5. The measured average apparent molecular size (Mw) increases from 7.7 to 22.1 kDa as a function of the extent of extraction. Carbon‐13 NMR and FTIR spectra of the fractions indicated that the contents of oxygen‐containing and aromatic functional groups decreased and the contents of aliphatic groups increased from Fr1 to Fr8. The results suggested that two subunits of HAs might exist: an aliphatic subunit having larger apparent Mw and an aromatic subunit having smaller apparent Mw We proposed that each of the eight HA fractions is a mixture of these two subunits.