Nitrogen and phosphorus emissions to water in agricultural crop-animal systems and driving forces in Hainan Island, China.

The NUFER (Nutrient Flow in food chains, Environment and Resources) model has been used to reliably quantify nitrogen (N) and phosphorus (P) emissions from agriculture land to water bodies. However, factors impacting agricultural N and P emissions at the island scale have rarely been studied due to the lack of high-resolution spatialization tools, which are critical for exploring mitigation options. Here, a high-resolution NUFER model was constructed based on geology, meteorology, land-use data, statistical data, and field investigation. The spatial characteristics of N and P emissions in Hainan Island, China, were quantified, and the driving forces were analyzed. We also explored effective measures to reduce emissions by 2035 using scenario analysis. Overall, 98 Gg N from agriculture entered water bodies in 2018, of which crop system contributed 70%; 15 Gg P entered water bodies, of which, animal system contributed 78%. Nitrate (NO3-) leaching (65%) and direct discharge of animal manure (69%) accounted for most of the N and P emissions, respectively. Plains contributed 89% of N and 92% of P emissions. Spatial overlay analysis showed that high N and P emissions were mainly concentrated in the western and northeastern plain areas. At the sub-basin scale, the Nandu River basin had the largest agricultural N and P emissions, accounting for more than 20% of all emissions. Scenario analysis showed that N and P emissions were significantly correlated with natural (e.g., elevation, slope, and soil texture) and anthropogenic (e.g., rural income, population density, planting structure, and livestock density) factors. We further analyzed the emissions of N and P can be reduced by 71 Gg and 14 Gg by 2035, respectively, via reducing food chain waste and consumption, importing more food, and improving production efficiency, but especially prohibiting the direct discharge of livestock manure. This high-resolution quantification of agricultural N and P emissions to the water bodies provides an exploration of the most effective options for reducing agricultural non-point source (ANPS) pollution at the island scale.

Spatiotemporal characteristics of agricultural nitrogen and phosphorus emissions to water and its source identification: A case in Bamen Bay，China.

The spatiotemporal characteristics and sources identification of agricultural nitrogen (N) and phosphorus (P) emissions to the gulf are rarely reported in tropical regions of China, mainly due to the lack of local reliable data and quantitative tools for spatiotemporal changes. In this study, we constructed a high-resolution NUFER (NUtrient Flow in food chains, Environment and Resources use) model based on geology, meteorology, land use data, statistical data, and field investigation to quantify the spatiotemporal characteristics and sources of N and P emissions. Bamen Bay (BMB), a bay with a mangrove national wetland Park in the Hainan Island, China, was chosen as a case study. The results showed that agricultural N emission to water in 2018 increased fivefold compared to 1990. Leaching was the main method of agricultural N emission and was mainly distributed in farms in the west and north. The contribution of N emission from crop system to water increased 20.3% in 28 years. Poultry and fruits have contributed the most to N output, and the trend is continuing. P emission to water increased sevenfold compared 1990. The contribution of P emission from animal system to water increased from 86.8% in 1990 to 90.1% in 2018 due to low removal rate of livestock manure. P emission was mainly via direct discharge of manure, mainly distributed in livestock breeding sites near the bay. Poultry has consistently contributed the most to P output in 28 years, accounting for 49.1% in 2018. Fertilizers and fodder were the largest sources of N and P. The average N and P loss rates of BMB were 5.32 t km2 yr-1 and 0.26 t km2 yr-1. The future agricultural transformation is essential, and it is necessary to reduce the application of N fertilizer and increase the removal rate of livestock manure. These results can provide reference for other typical agricultural pollution bays in exploring the spatiotemporal characteristics of N and P emissions to water and the identification of agricultural sources.

Alginate oligosaccharide improves lipid metabolism and inflammation by modulating gut microbiota in high-fat diet fed mice.

Alginate oligosaccharides are associated with some beneficial health effects. Gut microbiota is one of the most recently identified factors in the development of several metabolic diseases induced by high-fat diet. Our objective was to evaluate how alginate oligosaccharides impact on high-fat diet­induced features of metabolic disorders and whether this impact is related to modulations in the modulation of the gut microbiota. C57BL/6J mice were fed with chow diet, high-fat diet, or high-fat diet supplemented with alginate oligosaccharides for 10 weeks. Alginate oligosaccharide treatment improved lipid metabolism, such as reducing levels of TG and LDL-C and inhibiting expression of lipogenesis genes. Alginate oligosaccharide administration reduced the levels of fasting blood glucose and increased the levels of serum insulin. Alginate oligosaccharide treatment was found to lower the expression of markers of inflammation, including IL1ß and CD11c. Alginate oligosaccharide treatment modulated gut microbial communities and markedly prompted the growth of Akkermansia muciniphila, Lactobacillus reuteri, and Lactobacillus gasseri. Additionally, alginate oligosaccharide intervention significantly increased concentrations of short-chain fatty acids, such as acetic acid, propionic acid, and butyric acid, as well as decreased levels of endotoxin. Alginate oligosaccharides exert beneficial effects via alleviating metabolic metrics induced by high-fat diet, which is associated with increase in A. muciniphila, L. reuteri, and L. gasseri, as well as the release of microbiota-dependent short-chain fatty acids and inhibition of endotoxin levels.

Preparation of injectable temperature-sensitive chitosan-based hydrogel for combined hyperthermia and chemotherapy of colon cancer.

The purpose of this study was to design an injectable hydrogel with temperature-sensitive property for safe and high efficient in vivo colon cancer hyperthermia and chemotherapy. Chitosan (CS) solution was injected into the tumor at room temperature and automatically gelled after warming to body temperature in the present of ß-glycerophosphate (ß-GP). Combined localized tumor photothermal and chemotherapy were achieved by dissolving photothermal material MoS2/Bi2S3-PEG (MBP) nanosheets and drug molecule doxorubicin (DOX) into the hydrogel, and the gel system could encapsulate DOX and MBP nanosheets and prevent them from entering the blood circulation and damaging normal tissues and cells. More importantly, the CS/MBP/DOX (CMD) hydrogel exhibited a photothermal efficiency of 22.18% and 31.42% in the first and second near infrared light (NIR I and NIR II) biowindows respectively at a low MBP concentration (0.5 mg/mL). Besides, the release of the DOX from CMD hydrogel was controllable since the gel temperature could be governed by NIR laser irradiation. Moreover, the chitosan-based hydrogel had antibacterial effects. The designed composite hydrogel is anticipated to act as a platform for the high efficient treatment of tumors owing to the different penetration depths of NIR I and NIR II.

Photothermal transforming agent and chemotherapeutic co-loaded electrospun nanofibers for tumor treatment.

Background: Photothermal and chemotherapy treatment has been frequently studied for cancer therapy; however, chemotherapy is equally toxic to both normal and cancer cells. The clinical application value of most kinds of photothermal transforming agents remains limited, due to their poor degradation and minimal accumulation in tumors. Materials and methods: We reported the synthesis of photothermal transforming agents (MoS2) and chemotherapeutic (doxorubicin, DOX) co-loaded electrospun nanofibers using blend electrospinning for the treatment of postoperative tumor recurrence. Results: Under the irradiation of an 808 nm laser, the as-prepared chitosan/polyvinyl alcohol/MoS2/DOX nanofibers showed an admirable photothermal conversion capability with a photothermal conversion efficiency of 23.2%. These composite nanofibers are in vitro and in vivo biocompatible. In addition, they could control the sustained release of DOX and the generated heat can sensitize the chemotherapeutic efficacy of DOX via enhancing its release rate. Their chemo-/photothermal combined therapy efficiency was systematically studied in vitro and in vivo. Instead of circulating with the body fluid, MoS2 was trapped by the nanofibrous matrix in the tumor and so its tumor-killing ability was not compromised, thus rendering this composite nanofiber a promising alternative for future clinical translation within biomedical application fields. Conclusion: Chitosan/polyvinyl alcohol/MoS2/DOX nanofibers showed an excellent photothermal conversion capability with a photothermal conversion efficiency of 23.2% and can completely inhibit the postoperative tumor reoccurrence.

One-pot synthesis of polypyrrole nanoparticles with tunable photothermal conversion and drug loading capacity.

With an excellent near-infrared (NIR) light-responsive property, polypyrrole (PPy) nanoparticle has emerged as a promising NIR photothermal transducing agent for tumor photothermal therapy (PTT). Herein, we reported the PVP mediated one-pot synthesis of colloidal stable and biocompatible PPy nanoparticles (PPy-PVP NPs) for combined tumor photothermal-chemotherapy. The influence of molecular weight and PVP concentration on the spectroscopic characteristic, photothermal feature, drug loading performance, and antitumor efficiency of the resultant PPy-PVP NPs was systematically studied. By choosing PVP with a molecular weight of 360 kDa (concentration of 5 mg/mL) as the template and surface modifier during the synthesis, PPy-PVP NPs with optimal spectroscopic characteristic, photothermal feature, drug loading performance, and antitumor efficiency were synthesized. Findings in this study are anticipated to provide an in-depth understanding of the important character of surface engineering in the rational design and biomedical applications of PPy NPs.

Ginkgo biloba sarcotesta polysaccharide inhibits inflammatory responses through suppressing both NF-κB and MAPK signaling pathway.

BACKGROUND: Polysaccharides, common components of natural products extensively studied as dietary supplements and functional foods, have been found to have various activities. In the present study, a water-soluble polysaccharide, namely GBSP3a, was isolated and purified from G. biloba sarcotesta. The anti-inflammatory activity of GBSP3a in lipopolysaccharide (LPS)-induced RAW264.7 macrophages and the potential underlying molecular mechanisms were then assessed. RESULTS: GBSP3a exerted its anti-inflammatory effect by remarkably inhibiting the secretion of pro-inflammatory mediators and cytokines, including nitric oxide (NO), prostaglandin E2 (PGE2 ), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1ß (IL-1ß) in LPS-stimulated RAW264.7 macrophages. Excessive mRNA and protein expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were dose-dependently inhibited by GBSP3a in LPS-stimulated RAW264.7 cells. Further research suggested that the anti-inflammatory effect of GBSP3a can be attributed to the modulation of the NF-κB and MAPK signaling pathways. CONCLUSION: GBSP3a exhibits anti-inflammatory activity and exerts its anti-inflammatory effect probably through suppressing both NF-κB and MAPK signaling pathway, indicating that GBSP3a could be used for the development of anti-inflammatory agent or nutraceuticals. © 2018 Society of Chemical Industry.

Preparation of Poly(lactic-co-glycolic acid)-Based Composite Microfibers for Postoperative Treatment of Tumor in NIR I and NIR II Biowindows.

In this work, a novel kind of electrospun microfiber to deliver a photothermal agent and an anticancer drug to tumor sites is explored. Photothermal therapy agent (MoS2 nanosheets) and doxorubicin (DOX) are incorporated with poly(lactic-co-glycolic acid) (PLGA) microfiber via electrospinning a solution of PLGA, MoS2 , and DOX. The designed microfiber with uniform fibrous morphology and negligible in vitro/in vivo hemo-/histo-toxicity is used as a durable photothermal agent, which shows an excellent photothermal transform ability and acceptable photothermal stability in both the first and second near-infrared light (NIR I and II) biowindows. The synergistic in vivo tumor chemotherapy and photothermal therapy efficiency of the composite microfibers are studied in postoperative treatment of cancer. It is found that the tumor postoperative reoccurrence can be completely prohibited owing to the synergistic tumor therapy efficiency in both the NIR I and NIR II biowindows.

Design of Phase-Changeable and Injectable Alginate Hydrogel for Imaging-Guided Tumor Hyperthermia and Chemotherapy.

The objective of the present study was to construct an alginate (AG)-based phase-changeable and injectable hydrogel for imaging-guided tumor hyperthermia and chemotherapy. Based on the binding between the α-l-guluronic blocks of AG and calcium ions, the AG/MoS2/Bi2S3-poly(ethylene glycol) (MBP)/doxorubicin (DOX) solution formed a cross-linked hydrogel to simultaneously encapsulate MBP nanosheets and DOX within the hydrogel matrix. The in situ formed hydrogel can act as a reservoir to control the release of entrapped drug molecules, and the doped MBP nanosheets and DOX can realize computed tomography/photoacoustic dual-modal imaging-guided in vivo tumor photothermal therapy and chemotherapy, respectively. The AG/MBP/DOX hydrogel exhibited excellent photothermal conversion properties with mass extinction coefficient of 45.1 L/g/cm and photothermal conversion efficiency of 42.7%. Besides, the heat from the photothermal transformation of MBP can promote drug diffusion from the hydrogel to realize on-demand drug release. Additionally, the hydrogel system can restrain MBP and DOX from entering into the blood stream during therapy, and therefore substantially decrease their side effects on normal organs. More importantly, the drug loading of the AG hydrogel was general and can be extended to the encapsulation of antibiotics, such as amoxicillin, for the prevention of postoperative infections.