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The soil environment plays an important role in urban ecosystems. To study the heavy metal contamination of soil in Beilun District, Ningbo, we collected soil samples from 60 points in urban and peri-urban areas of Beilun District and analyzed the spatiotemporal variation and sources of heavy metal pollution in various land-use types. The results shown that the heavy metal contents in 2015 and 2022 were higher than the background soil values of Ningbo city, and there was an accumulation of heavy metals over these 7 years. The contents of heavy metals in green belts and woodland in 2022 were higher than those in 2015, while there was no significant change in agricultural land. The heavy metal contents in both years were mainly in the order green belts > agricultural land > woodland. The spatiotemporal distribution of heavy metal content showed that heavy metal pollution in Beilun District was concentrated in five industrial areas, and there was a trend toward the disappearance of highly polluted points. But the single-factor pollution index, pollution load index (PLI), and geoaccumulation index (I geo ) indicated that there was no significant heavy metal pollution in Beilun District, and individual elements at specific points showed slight pollution. The source analysis results showed that the main source of Hg is chemical, As is mainly derived from agricultural, Cr, Ni and Cu are mainly derived from natural, the main sources of Zn and Cd are electroplating and machinery activities, and the main source of Pb is traffic. These results specify a reference for future investigation on urban soil heavy metals, and the source apportionment results provide a scientific foundation for subsequent soil heavy metal pollution treatment.

Polysaccharides are very promising molecules in the field of pharmacotherapy. Knowing this, the aim of this study was to extract, characterize, and evaluate the action of the polysaccharides in noni juice, using biological models of Type 2 diabetes mellitus processes. In this study, one polysaccharide named NJSPd−1 was separated from fermented noni fruit juice. The characterization assay showed that NJSPd−1 had a molecular weight (Mw) of 18,545 Da. NJSPd−1 consisted of galacturonic acid, galactose, rhamnose, and arabinose, with a molar ratio of 28.79:20.34:19.80:18.84 according to HPGPC analysis, and the glycosidic bond mainly included →4)-α-D-GalAp-(1→, 4)-β-D-Glcp-(1→, →2)-α-L-Rhap-(1→, and →3)-α-L-Araf-(1→. The prevention of oxidative stress activities by NJSPd−1 was evaluated using high-glucose-induced oxidative stress in HepG2 cells. In vitro results showed that NJSPd−1 influenced the downregulation of the proteins and genes Nrf2, Keap1, HO-1, and NQO1 in HepG2 cells. These results suggest that NJSPd−1 exerted a protective effect against oxidative stress in HepG2 cells by activating the Nrf2/HO-1/NQO1 signaling pathway.

E-waste generation has become a major environmental issue worldwide. Heavy metals (HMs) in e-waste can be released during inappropriate recycling processes. While their pollution characteristics have been studied, the migration and transformation of different multi-metal fractions in soil–plant system of e-waste dismantling sites is still unclear. In this study, pot experiments were conducted to investigate the migration and transformation of different multi-metal fractions (Cu, Pb, Zn and Al) in the soil–plant system using two Chinese cabbage cultivars (heavy metals low-accumulated variety of Z1 and non-low-accumulated Z2) treated with or without biochar. The result showed that the acid-soluble fraction of Cu, Pb, Zn and Al in soil decreased by 5.5%, 55.7%, 7.8% and 21.3%, but the residual fraction (ResF) of them increased by 48.5%, 1.8%, 30.9% and 43.1%, respectively, when treated with biochar and plants, compared to that of the blank soil (CK). In addition, Pb mainly existed as a reducible fraction, whereas Cu existed as an oxidisable fraction. Biochar combined with plants significantly increased the ResF of multi-metals, which reduced the migration ability of Pb among all other metals. The relative amount of labelled 13C in the soil of Z1 was higher than that of Z2 (25.4 fold); among them, the Gram-negative bacteria (18-1ω9c, 18-1ω7c) and fungi (18-2ω6c) were significantly labelled in the Z1-treated soil, and have high correlation with HM migration and transformation. In addition, Gemmatimonadete were significantly positive in the acid-soluble fraction of HMs, whereas Ascomycota mostly contributed to the immobilisation of HMs. Therefore, the distribution of fractions rather than the heavy metal type plays an important role in the HM migration in the soil–plant system of e-waste dismantling sites.

Middle East respiratory syndrome coronavirus (MERS-CoV) with potential to cause global pandemics remains a threat to the public health, security, and economy. In this review, we focus on advances in the research and development of small-molecule MERS-CoV inhibitors targeting different stages of the MERS-CoV life cycle, aiming to prevent or treat MERS-CoV infection.

Metal oxide nanoparticles (NPs) have been widely used in industrial and agricultural production and introduced into soils. The impact of these nanoparticles on soil nitrous oxide (N2O) emission is unclear. We conducted a microcosm experiment to investigate the effects of titanium oxide nanoparticles (TiO2 NPs), copper oxide nanoparticles (CuO NPs), and aluminum oxide nanoparticles (Al2O3 NPs) on soil N2O emissions and the abundance of functional genes related to N2O production/reduction. Compared to the soil without NPs addition, TiO2 NPs applied to the soil produced no significant effect on N2O emissions. The denitrification process in the soil exposed to CuO NPs was inhibited by reducing the functional genes related to nitrite reductase (nirK) and increasing N2O reductase (nosZ), while CuO NPs added to the soil stimulated the cumulative N2O emissions by 92.7%. After the application of Al2O3 NPs to the soil, the nitrification process was inhibited by inhibiting the functional genes of ammonia-oxidizing bacteria (AOB amoA), and soil N2O emission was reduced by 48.6%. Large-scale application of CuO NPs in agricultural soils may stimulate the N2O emissions resulting in potential environmental risks.

Hyperspectral remote sensing can be used to effectively identify contaminated elements in soil. However, in the field of monitoring soil heavy metal pollution, hyperspectral remote sensing has the characteristics of high dimensionality and high redundancy, which seriously affect the accuracy and stability of hyperspectral inversion models. To resolve the problem, a gradient boosting regression tree (GBRT) hyperspectral inversion algorithm for heavy metal (Arsenic (As)) content in soils based on Spearman’s rank correlation analysis (SCA) coupled with competitive adaptive reweighted sampling (CARS) is proposed in this paper. Firstly, the CARS algorithm is used to roughly select the original spectral data. Second derivative (SD), Gaussian filtering (GF), and min-max normalization (MMN) pretreatments are then used to improve the correlation between the spectra and As in the characteristic band enhancement stage. Finally, the low-correlation bands are removed using the SCA method, and a subset with absolute correlation values greater than 0.6 is retained as the optimal band subset after each pretreatment. For the modeling, the five most representative characteristic bands were selected in the Honghu area of China, and the nine most representative characteristic bands were selected in the Daye area of China. In order to verify the generalization ability of the proposed algorithm, 92 soil samples from the Honghu and Daye areas were selected as the research objects. With the use of support vector machine regression (SVMR), linear regression (LR), and random forest (RF) regression methods as comparative methods, all the models obtained a good prediction accuracy. However, among the different combinations, CARS-SCA-GBRT obtained the highest precision, which indicates that the proposed algorithm can select fewer characteristic bands to achieve a better inversion effect, and can thus provide accurate data support for the treatment and recovery of heavy metal pollution in soils.

With growing public concern about the health effects of low-dose radiation, numerous studies have demonstrated that low-dose radiation can cause damage to the immune system, making intervention measures essential. This study investigated the protective effects of silybin against low-dose radiation-induced immune system damage and its underlying mechanisms at both the cellular and animal levels. At the cellular level, CCK-8 assays, ROS measurements, and RT-qPCR analysis revealed that silybin alleviated the reduction in RAW264.7 cell proliferation, intracellular ROS levels, and inflammatory cytokine expression following low-dose radiation exposure. At the animal level, comparative analyses of post-irradiation body weight, peripheral blood cell counts, immune organ coefficients, spleen HE/IHC staining, and spleen immune cell numbers demonstrated that silybin mitigated the radiation-induced decrease in body weight, reduction in peripheral blood leukocyte counts, inflammatory cell infiltration in the spleen, decline in spleen immune cell numbers, and increase in cGAS protein-positive cells. These findings indicate that silybin exerts protective effects against low-dose radiation-induced immune system damage, potentially by regulating the cGAS signaling pathway to reduce radiation-induced cellular injury, thereby enhancing its radioprotective properties.

Background To investigate the epidemiology of Klebsiella pneumoniae ( K. pneumoniae ) inducing pyogenic liver abscess (PLA) in east China and the role of hypervirulent carbapenem-resistant K. pneumoniae (Hv-CRKP). Methods Forty-three K. pneumoniae strains were collected from 43 patients with PLA at Hangzhou, China in 2017. Antimicrobial susceptibility tests, string test, multilocus sequence typing, pulsed-field gel electrophoresis, mobile genetic elements typing, regular PCR and sequencing, and Galleria mellonella ( G. mellonella ) lethality test were used to elucidate the epidemiology. Clinical data were collected. Results K. pneumoniae strains with serotypes K1 and K2 accounted for 69.8%, which shared 46.5% and 23.3% respectively. K. pneumoniae strains with clonal group 23 were predominant with a rate of 34.9%. Such antimicrobials showed susceptible rates over 80.0%: cefuroxime, cefotaxime, gentamycin, ticarcillin/clavulanate, ceftazidime, cefoperazone/tazobactam, cefepime, aztreonam, imipenem, meropenem, amikacin, tobramycin, ciprofloxacin, levofloxacin, doxycycline, minocycline, tigecycline, chloramphenicol, and trimethoprim-sulfamethoxazole. PFGE dendrogram showed 29 clusters for the 43 K. pneumoniae strains. Three Hv-CRKP strains were confirmed by G. mellonella lethality test, showing a constituent ratio of 7.0% (3/43). Totally three deaths were found, presenting a rate of 7.0% (3/43). The three died patients were all infected with Hv-CRKP. Conclusions K1 and K2 are the leading serotypes of K. pneumoniae causing PLA, which show highly divergent genetic backgrounds. Aminoglycosides, Generation 2 nd to 4 th cephalosporins, β-lactamase/β-lactamase inhibitors, carbapenems, fluoroquinolones are empirical choices. Hv-CRKP may confer an urgent challenge in the future.

Polygonatum sibiricum polysaccharides (PSPs) have important biological functions, such as antioxidation, immunomodulatory, and hypolipidemic functions. Different extraction methods have effects on their structures and activities. In this study, six extraction methods, including hot water extraction (HWE), alkali extraction (AAE), ultrasound-assisted extraction (UAE), enzyme-assisted extraction (EAE), microwave-assisted extraction (MAE), and freeze–thaw-assisted extraction (FAE) were used to extract PSPs, and their structure–activity relationships were analyzed. The results showed that all six PSPs had similar functional group compositions, thermal stability, and glycosidic bond compositions. PSP-As (PSPs extracted by AAE) exhibited better rheological properties due to their higher molecular weight (Mw). PSP-Es (PSPs extracted by EAE) and PSP-Fs (PSPs extracted by FAE) had better lipid-lowering activity due to their lower Mw. PSP-Es and PSP-Ms (PSPs extracted by MAE), which do not contain uronic acid and have a moderate Mw, had better 1,1-diphenyl-2-picrylhydrazyl (DPPH)-radical-scavenging activity. On the contrary, PSP-Hs (PSPs extracted by HWE) and PSP-Fs, with the Mw of uronic acid, had the best OH-radical-scavenging activity. The high-Mw PSP-As had the best Fe2+-chelating ability. In addition, mannose (Man) may play an important role in the immunomodulatory activity. These results indicate that different extraction methods affect the structure and biological activity of polysaccharides to varying degrees, and these results are helpful for understanding the structure–activity relationship of PSPs.

Green-synthesized metal nanoparticles show promise in nanomedicine and material engineering. In this study, the polysaccharide of Zingiber officinale (ZOP) was used as a raw material. Through single-factor experiments and a response surface methodology, the optimum synthesis protocol of Zingiber officinale polysaccharide silver nanoparticles (ZOP-NPs-AgNPs) was determined as follows: V(AgNO3):V(ZOP) = 2.98:1, 59.79 °C, 3 h, pH 9, and 20 mL NaCl, achieving a 92.51% silver chelation rate. Structure analysis revealed that ZOP-NPs-AgNPs were spherical or quasi-spherical, with a particle size < 20 nm and a face-centered cubic crystal structure, which has good thermal stability. Subsequent studies explored the antibacterial and immunomodulatory effects of ZOP-NPs-AgNPs. The minimum inhibitory concentration (MIC) of ZOP-NPs-AgNPs against Escherichia coli and Staphylococcus aureus was determined to be 0.5000 mg/mL and 0.0310 mg/mL, respectively, while the minimum bactericidal concentration (MBC) was 0.5000 mg/mL and 0.0310 mg/mL, respectively. Additionally, ZOP-NPs-AgNPs significantly enhance RAW264.7 cell proliferation and phagocytosis and boost IL−1β, IL−6, NO, and TNF-α production. This confirms that ZOP can act as a green reductant and stabilizer, offering a new method for green nano-silver synthesis. This provides a sustainable way to produce antibacterial products and functional foods, and offers useful references for eco-friendly nano-silver applications.