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Dissolved organic matter (DOM) in soils drives biogeochemical cycling and soil functions in different directions depending on its molecular signature. Notably, there is a distinct paucity of information concerning how the molecular signatures of soil DOM vary with different degrees of weathering across wide geographic scales. Herein, we resolved the DOM molecular signatures from 22 diverse Chinese reference soils and linked them with soil organic matter and weathering-related mineralogical properties. The mixed-effects models revealed that the yields of DOM were determined by soil organic carbon content, whereas the molecular signature of DOM was primarily constrained by the weathering-related dimension. The soil weathering index showed a positive effect on the lability and a negative effect on the aromaticity of DOM. Specifically, DOM in highly weathered acidic soils featured more amino sugars, carbohydrates, and aliphatics, as well as less O-rich polyphenols and condensed aromatics, thereby conferring a higher DOM biolability and lower DOM aromaticity. This study highlights the dominance of the weathering-related dimension in constraining the molecular signatures and potential functions of DOM in soils across a wide geographic scale.

Objective To discuss the current situation and challenge to the treatment strategy for elderly patients with advanced gastric cancer and provide reference for the exploration of ideal treatment methods. Methods Collect the clinical material of an elderly patient with advanced gastric cancer, and the relevant literatures were reviewed. Results A 79-year-old man was clinically diagnosed as adenocarcinoma on the fundus of stomach (cT4a-bN2Mx). After the third course of neo-adjuvant concurrent chemo-radiotherapy, a remarkable reduction and down-staging was achieved (cT3-4N1Mx), then followed by radical gastrectomy for gastric cancer. S1 was used alone for the postoperative chemotherapy. The patient received nutritional therapy in the full treatment course, and the physical condition was satisfactory without tumor metastasis and relapse two years and a half after the surgery. Conclusions The sequentially comprehensive therapy suggestes a treatment therapy for elderly patients with advanced gastric cancer, and deserves further verification and promotion clinically.

Flavonoids, which contain a benzo‐γ‐pyrone (C6–C3–C6) skeleton, have been reported to exhibit effective antioxidant ability. This study aimed to compare the antioxidant activities of 7,8‐dihydroxyflavone (7,8‐DHF) and 7‐hydroxyflavone (7‐HF) in H2O2, lipopolysaccharide (LPS), or tert‐butyl hydroperoxide (t‐BHP)‐induced RAW264.7 cells, respectively. The antioxidant capacities of 7,8‐DHF and 7‐HF were firstly evaluated by 2,2‐azinobis‐3‐ethyl‐benzothiazoline‐6‐sulphonic acid (ABTS), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Then, reactive oxygen species (ROS), super oxide dismutase (SOD), and malondialdehyde (MDA) productions in H2O2, LPS, or t‐BHP‐induced RAW264.7 cells were tested and compared, respectively. Finally, the antioxidant mechanisms of 7‐HF and 7,8‐DHF were initially investigated by western blot. Our results showed that 7,8‐DHF possessed stronger free‐radical scavenging capacity than 7‐HF. Both 7,8‐DHF and 7‐HF suppressed MDA production and ROS accumulation, improved the activity of SOD in H2O2, LPS, or t‐BHP‐induced RAW264.7 cells, respectively. And 7,8‐DHF exerted a better antioxidant effect than 7‐HF, especially in t‐BHP‐induced oxidative stress. Mechanically, 7,8‐DHF prevented the activation of poly ADP‐ribosepolymerase and caspase‐3, meanwhile markedly upregulated the expression of HO‐1 protein in t‐BHP‐induced oxidative stress. These results suggested that 7,8‐DHF might serve as a potential pharmaceutical drug against oxidative stress injury. [ABSTRACT FROM AUTHOR]

The antibacterial secondary metabolites of the fungus Penicillium chrysogenum associated with the beetle Aspongopus chinensis were investigated through chromatographic fractionation methods of ethyl acetate extracts of the fungal cultures. Five compounds were isolated, and their structures were determined as emodin, 4-(methoxymethyl)benzoic acid, isoochracinic acid, secalonic acid D, and dicerandrol A using mass spectroscopy and nuclear magnetic resonance spectroscopic analyses. Emodin exhibited strong antimicrobial activity, especially against Staphylococcus aureus even when growing on cooked pork, with a minimal inhibitory concentration (MIC) of 6.3 μg/mL. Dimeric tetrahydroxanthones, such as secalonic acid D and dicerandrol A, also exhibited potent activity, with MIC values ranging from 9.5 to 28.5 μg/mL. In summary, P. chrysogenum was isolated as a symbiotic fungus of the beetle A. chinensis for the first time and this strain could generate antibacterial secondary metabolites, which could potently inhibit gram-positive bacteria growth in vitro.