Carbonized cellulose microspheres loaded with Pd NPs as catalyst in p-nitrophenol reduction and Suzuki-Miyaura coupling reaction.

Catalytic reduction of p-nitrophenol is usually carried out using transition metal nanoparticles such as gold, palladium, silver, and copper, especially palladium nanoparticles (Pd NPs), which are characterized by fast reaction rate, high turnover frequency, good selectivity, and high yield. However, the aggregation and precipitation of the metals lead to the decomposition of the catalyst, which results in a significant reduction of the catalytic activity. Therefore, the preparation of homogeneous stabilized palladium nanoparticles catalysts has been widely studied. Stabilized palladium nanoparticles mainly use synthetic polymers. Cellulose microspheres, as a natural polymer material with low-cost and porous fiber network structure, are excellent carriers for stabilizing metal nanoparticles. Cellulose microspheres impregnated with palladium metal nanoparticles were carbonized to have a larger specific surface area and highly dispersed palladium nanoparticles, which exhibited excellent catalytic activity in the catalytic reduction of p-nitrophenol. In this work, the cellulose carbon-based microspheres palladium (Pd@CCM) catalysts were designed and characterized by SEM, TEM, EDS, XRD, FTIR, XPS, TGA, BET, and so on. Furthermore, the catalytic performance of Pd@CCM catalysts was investigated via p-nitrophenol reduction, which showed high catalytic activity. This catalyst also exhibited excellent catalytic performance in the Suzuki-Miyaura coupling reaction. Linking aromatic monomer and benzene through Suzuki-Miyaura coupling was presented as an effective route to obtaining biaryls, and the synthesis method is low-cost and simple. In addition, Pd@CCM showed desirable recyclability while maintaining its catalytic activity even after five recycles. This work is highly suggestive of the design and application of the heterogeneous catalyst.

Double pyramid stacked CoO nano-crystals induced by graphene at low temperatures as highly efficient Fenton-like catalysts.

Transition metal oxides are widely used as Fenton-like catalysts in the treatment of organic pollutants, but their synthesis usually requires a high temperature. Herein, an all-solid-state synthesis method controlled by graphene was used to prepare a double pyramid stacked CoO nano-crystal at a low temperature. The preparation temperature decreased by 200 °C (over 30% reduction) due to the introduction of graphene, largely reducing the reaction energy barrier. Interestingly, the corresponding degradation rate constants (kobs) of this graphene-supported pyramid CoO nano-crystals for organic molecules after their adsorption were over 2.5 and 35 times higher than that before adsorption and that of free CoO, respectively. This high catalytic efficiency is attributed to the adsorption of pollutants at the surface by supporting graphene layers, while free radicals activated by CoO can directly and rapidly contact and degrade them. These findings provide a new strategy to prepare low carbon-consuming transition metal oxides for highly efficient Fenton-like catalysts.

Mitigation Effects of Bentonite and Yeast Cell Wall Binders on AFB1, DON, and OTA Induced Changes in Laying Hen Performance, Egg Quality, and Health.

The objective of this study was to evaluate the efficacy of mycotoxin binders in reducing the adverse effects of co-occurring dietary aflatoxin B1 (AFB1), deoxynivalenol (DON) and ochratoxin A (OTA) on laying hens. Three hundred and sixty 26-week-old Roman laying hens were randomly allocated into four experimental groups with 10 replicates of nine birds each. The four groups received either a basal diet (BD; Control), a BD supplemented with 0.15 mg/kg AFB1 + 1.5 mg/kg DON + 0.12 mg/kg OTA (Toxins), a BD + Toxins with Toxo-HP binder (Toxins + HP), or a BD + Toxins with TOXO XL binder (Toxins + XL) for 12 weeks. Compared to the control, dietary supplementation of mycotoxins decreased (P < 0.10) total feed intake, total egg weight, and egg-laying rate, but increased feed/egg ratio by 2.5-6.1% and mortality during various experimental periods. These alterations induced by mycotoxins were alleviated by supplementation with both TOXO HP and XL binders (P < 0.10). Furthermore, dietary mycotoxins reduced (P < 0.05) eggshell strength by 12.3% and caused an accumulation of 249 µg/kg of DON in eggs at week 12, while dietary supplementation with TOXO HP or XL mitigated DON-induced changes on eggshell strength and prevented accumulation of DON in eggs (P < 0.05). Moreover, dietary mycotoxins increased relative liver weight, but decreased spleen and proventriculus relative weights by 11.6-22.4% (P < 0.05). Mycotoxin exposure also increased alanine aminotransferase activity and reduced immunoglobulin (Ig) A, IgM, and IgG concentrations in serum by 9.2-26.1% (P < 0.05). Additionally, mycotoxin exposure induced histopathological damage and reduced villus height, villus height/crypt depth, and crypt depth in duodenum, jejunum and (or) ileum (P < 0.05). Notably, most of these histological changes were mitigated by supplementation with both TOXO HP and XL (P < 0.05). In conclusion, the present study demonstrated that the mycotoxin binders TOXO HP and XL can help to mitigate the combined effects of AFB1, DON, and OTA on laying hen performance, egg quality, and health.

Recent Progress in High-Strength and Robust Regenerated Cellulose Materials.

High-strength petroleum-based materials like plastics have been widely used in various fields, but their nonbiodegradability has caused serious pollution problems. Cellulose, as the most abundant sustainable polymer, has a great chance to act as the ideal substitute for plastics due to its low cost, wide availability, biodegradability, etc. Herein, the recent achievements for developing cellulose "green" solvents and regenerated cellulose materials with high strength via the "bottom-up" route are presented. Cellulose can be regenerated to produce films/membranes, hydrogels/aerogels, filaments/fibers, microspheres/beads, bioplastics, etc., which show potential applications in textiles, biomedicine, energy storage, packaging, etc. Importantly, these cellulose-based materials can be biodegraded in soil and oceans, reducing environmental pollution. The cellulose solvents, dissolving mechanism, and strategies for constructing the regenerated cellulose functional materials with high strength and performances, together with the current achievements and urgent challenges are summarized, and some perspectives are also proposed. The near future will be an exciting era for high-strength biodegradable and renewable materials. The hope is that many environmentally friendly materials with good properties and low cost will be produced for commercial use, which will be beneficial for sustainable development in the world.

Highly substituted decoupled gelatin methacrylamide free of hydrolabile methacrylate impurities: An optimum choice for long-term stability and cytocompatibility.

Gelatin methacryloyl (GelMA; GM) contains impurities, including hydrolabile photosensitive methacrylate groups or soluble methacrylic acid (MA), which could be potentially detrimental to its in vitro and in vivo applications. To date, the influence of GM photocurable side chains on the cytotoxicity and ambient structural stability has remained to be investigated. Here, we successfully separated highly substituted decoupled gelatin methacrylamide (DGM) from GM via removing methacrylate impurities in order to evaluate its stability, cell viability, and cell toxicity, compared to GM, DGM plus soluble MA, and soluble MA. The photocurable methacrylate groups in GM were hydrolytically labile in neutral solutions, changing into soluble MA over time; on the other hand, the photocurable methacrylamide groups in DGM remained intact under the same conditions. Soluble MA was found to decrease cell viability in a dose dependent manner and caused severe cell toxicity at above 10 mg/mL. DGM plus MA started to impair cell viability at a 25 mg/mL concentration. DGM exhibited excellent cell viability and little cell toxicity across the treated concentrations (0.1-25 mg/mL). DGM without hydrolabile methacrylate and cytotoxic MA impurities could be a better choice for long term stability and good cell compatibility for bioapplications including bioprinting and cell encapsulation.

Effect of deoxynivalenol on the porcine acquired immune response and potential remediation by a novel modified HSCAS adsorbent.

The objective of this study was to determine the immunotoxic effects of deoxynivalenol (DON) in weaning piglets, and potential efficacy of a modified hydrated sodium calcium aluminosilicate (HSCAS) adsorbent to reduce DON toxicity. Four groups of 21-day-old male piglets (n = 7/group) were fed a control diet or diet containing 1.0 or 3.0 mg DON/kg, or 3.0 mg DON/kg plus 0.05% modified HSCAS for 4 weeks. Compared to the control, the DON diets decreased serum porcine circovirus antibody titer and the dermal hypersensitivity response to OVA at day 21 or 28. DON also induced focal necrosis and proliferation of cortical lymphocytes and apoptosis and increased the total antioxidant capacity and reduced glutathione, protein carbonyl concentrations in thymus. DON increased thymus mRNA, protein and (or) enzyme levels, cytokines (IL-6, IL-10, and TNF-α) and apoptosis-related genes (Caspase-3), while hematopoietic cell kinase (HCK) decreased. Intriguingly, the modified HSCAS alleviated the DON-induced changes on serum antibody titer, and thymic histopathology, apoptosis, redox status, inflammation and apoptosis signaling. In conclusion, these findings help to explain the toxic effects and mechanisms of DON and demonstrated the modified HSCAS adsorbent could be used to reduce the toxicity of DON in weaning piglets.

Photocurable Albumin Methacryloyl Hydrogels as a Versatile Platform for Tissue Engineering.

Photopolymerization of protein-derived polymers functionalized with methacryloyl groups has been increasingly used to fabricate three-dimensional tissue constructs for biomedical applications because photocurable protein-based polymers (e.g., gelatin and collagen methacryloyl) feature spatial-temporal controllability of engineering complex constructs as well as inherent biological properties. Herein, we report photocurable albumin-based hydrogels. First, photocurable bovine serum albumin methacryloyl (BSA-MA) with different degrees of substitution (DM) was successfully synthesized in a precise manner, without substantially altering BSA native secondary structure. Resultant photocurable BSA-MA hydrogels exhibited tunable physio-biochemical properties over the swelling, degradation, and mechanical properties. Moreover, photo-cross-linked BSA-MA hydrogels provided a permissible environment to support cell viability and functionality both in two- and three-dimensional culture systems. Photocurable BSA-MA hydrogels may be used as a versatile platform for various bioapplications including tissue engineering and 3D bioprinting.

Gelatin methacryloyl and its hydrogels with an exceptional degree of controllability and batch-to-batch consistency.

Gelatin methacryloyl (GelMA) is a versatile material for a wide range of bioapplications. There is an intense interest in developing effective chemical strategies to prepare GelMA with a high degree of batch-to-batch consistency and controllability in terms of methacryloyl functionalization and physiochemical properties. Herein, we systematically investigated the batch-to-batch reproducibility and controllability of producing GelMA (target highly and lowly substituted versions) via a one-pot strategy. To assess the GelMA product, several parameters were evaluated, including the degree of methacryloylation, secondary structure, and enzymatic degradation, along with the mechanical properties and cell viability of GelMA hydrogels. The results showed that two types of target GelMA with five batches exhibited a high degree of controllability and reproducibility in compositional, structural, and functional properties owing to the highly controllable one-pot strategy.

Thermoresponsive Polymers with Lower Critical Solution Temperature- or Upper Critical Solution Temperature-Type Phase Behaviour Do Not Induce Toxicity to Human Endothelial Cells.

Thermoresponsive polymers have gained extensive attention as biomedical materials especially for targeted drug delivery systems. We have recently developed water-soluble polypeptide-based thermoresponsive polymers that exhibit lower critical solution temperature (LCST)- or upper critical solution temperature (UCST)-type phase behaviours. In this study, the toxicity of these polymers to human umbilical vein endothelial cells (HUVECs) was investigated to assess the safety and biocompatibility. Up to 100 µg/ml, thermoresponsive polymers did not induce cytotoxicity to HUVECs, showing as unaltered mitochondrial viability assessed as cell counting kit-8 (CCK-8) assay and membrane integrity assessed as lactate dehydrogenase (LDH) assay. Inflammatory response, assessed as the release of chemokine-soluble monocyte chemotactic protein 1 (sMCP-1) and interleukin-8 (IL-8) as well as cytokine IL-6, was not significantly affected by the polymers. In addition, 1 µM thapsigargin (TG), an endoplasmic reticulum (ER) stress inducer, significantly decreased mitochondrial viability, but did not affect membrane integrity or inflammatory response. The presence of thermoresponsive polymers with LCST-type phase behaviour did not further affect the effects of TG. In conclusion, the thermoresponsive polymers used in this study are not toxic to endothelial cells and therefore could be further considered as safe materials for biomedical applications.

[Dioxin Pollution and Occupational Inhalation Exposure of PCDD/Fs in Municipal Solid Waste Incinerator].

To assess the pollution levels, characteristics, and the pollution sources and occupational inhalation exposure of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)in the workshops,ambient air samples in different types of incinerators of two municipal solid waste incinerators(MSWI) were collected and analyzed. The results showed that ① The I-TEQ concentration ranged from 0.034-2.152 pg·m-3in the two waste incineration plants, and the most sites' I-TEQ exceeded the ambient air quality standard. Besides, the I-TEQ concentration behind the incineration plant was higher than others. ② The dioxins in incineration plant were dominated by OCDD and 1,2,3,4,6,7,8-HpCDD. For MSWI A, the flue gas and the fly ash had major effect on PCDD/Fs, while the dioxins pollution in MSWI B was only affected by the fly ash. ③ Occupational inhalation exposure of PCDD/Fs was 0.01-1.10 pg·(kg·d)-1 in incineration plant, some occupational inhalation exposure values exceeded the evaluation standard, and the areas behind the incinerators were evaluated to have a high exposure risk.