Alpha-lipoic acid (ALA) ameliorates early brain injury after subarachnoid hemorrhage in Sprague-Dawley (SD) rats via inhibiting STING-NLRP3 inflammatory signaling.

Neuroinflammation is intimately associated with poor prognosis in patients with subarachnoid hemorrhage (SAH). Alpha-lipoic acid (ALA), a disulfide antioxidant, has been shown to be neuroprotective in an in vivo model of neurological injury; however, the role of ALA in SAH has never been evaluated. In this study, the Sprague-Dawley rats SAH model was induced by endovascular perforation method. ALA was transplanted intravenously into rats, and SR-717, a stimulator of interferon genes (STING) agonist, was injected intraperitoneally. The effects of ALA on early brain injury were assayed by neurological score, hematoxylin and eosin staining and Nissl staining. Immunohistochemistry staining and Western blotting were used to analyze various proteins. ALA significantly reduced STING- NLRP3 protein expression and decreased cell death, which in turn mitigated the neurobehavioral dysfunction following SAH. Furthermore, coadministration of ALA and SR-717 promoted STING-NLRP3 signaling pathway activation following SAH, which reversed the inhibitory effect of ALA on STING-NLRP3 protein activation and increased the neurological deficits. In conclusion, ALA may be a promising therapeutic strategy for alleviating early brain injury after SAH.

Supported Ruthenium Single-Atom and Clustered Catalysts Outperform Benchmark Pt for Alkaline Hydrogen Evolution.

Guaranteeing satisfactory catalytic behavior while ensuring high metal utilization has become the problem that needs to be addressed when designing noble-metal-based catalysts for electrochemical reactions. Here, well-dispersed ruthenium (Ru) based clusters with adjacent Ru single atoms (SAs) on layered sodium cobalt oxide (Ru/NC) are demonstrated as a superb electrocatalyst for alkaline HER. The Ru/NC catalyst demonstrates an activity increase by a factor of two relative to the commercial Pt/C. Operando characterizations in conjunction with density functional theory (DFT) simulations uncover the origin of the superior activity and establish a structure-performance relationship, that is, under HER condition, the real active species are Ru SAs and metallic Ru clusters supported on the NC substrate. The excellent alkaline HER activity of the Ru/NC catalyst can be understood by a spatially decoupled water dissociation and hydrogen desorption mechanism, where the NC substrate accelerates the water dissociation rate, and the generated H intermediates would then migrate to the Ru SAs or clusters and recombine to have H2 evolution. More importantly, comparing the two forms of Ru sites, it is the Ru cluster that dominates the HER activity.

Cross-Border E-Commerce Intelligent Information Recommendation System Based on Deep Learning.

In order to improve the effect of cross-border e-commerce intelligent information recommendation, this paper applies deep learning to the intelligent information processing and intelligent recommendation of e-commerce and proposes an improved version of the topic model to solve the problem of feature extraction of the text of the recommendation system. In order to deal with translation problems, this paper proposes an end-to-end sequence-to-sequence learning method. In addition, this study uses the long tail theory to excavate the mass commodities in the niche and recommends these products to users as suggestions. Finally, this paper proposes a niche product recommendation algorithm based on the graph search strategy based on the graph model. The experiment shows that the cross-border e-commerce intelligent information recommendation system based on deep learning proposed in this paper has a good recommendation effect and meets the recommendation needs of cross-border e-commerce.

Study on the Role of Quartz in the Bio-Oxidation of Sulfide Minerals From Mine Solid Waste.

Sulfide-containing mine waste was oxidized to produce acid mine drainage, which lead to acidification of surrounding soil and downstream rivers and posed a threat to the surrounding environment. Quartz often coexists with sulfide minerals and affects the oxidation of sulfide minerals. In order to explore the role of quartz in the bio-oxidation of sulfide minerals in mine solid waste, the mixed minerals of quartz and sulfide minerals were bio-oxidized by Acidithiobacillus ferrooxidans. The results showed that quartz could improve the microbial activity and increase the acid production of sulfide minerals. The larger the proportion of quartz in bio-oxidation of sulfide minerals, the less the production of secondary minerals such as jarosite, and the larger the leaching amount of iron and sulfate. This research provides new ideas for speeding up the bio-oxidation of sulfide mineral to remove iron and sulfate. It provides a new way to solve acid pollution caused by oxidation of sulfide minerals.

Revealing two important tryptophan residues with completely different roles in a dye-decolorizing peroxidase from Irpex lacteus F17.

BACKGROUND: Dye-decolorizing peroxidases (DyPs) represent a novel family of heme peroxidases that use H2O2 as the final electron acceptor to catalyze the oxidation of various organic compounds. A DyP from Irpex lacteus F17 (Il-DyP4, corresponding to GenBank MG209114), obtained by heterologous expression, exhibits a high catalytic efficiency for phenolic compounds and a strong decolorizing ability toward various synthetic dyes. However, the enzyme structure and the catalytic residues involved in substrate oxidation remain poorly understood. RESULTS: Here, we obtained a high-resolution structure (2.0 Å, PDB: 7D8M) of Il­DyP4 with α-helices, anti-parallel ß-sheets and one ferric heme cofactor sandwiched between two domains. The crystal structure of Il­DyP4 revealed two heme access channels leading from the enzyme molecular surface to its heme region, and also showed four conserved amino acid residues forming the pocket for the conversion of hydrogen peroxide into the water molecule. In addition, we found that Trp264 and Trp380, were two important residues with different roles in Il­DyP4, by using site-directed mutagenesis and an electron paramagnetic resonance (EPR) study. Trp264 is a noncatalytic residue that mainly is used for maintaining the normal spatial conformation of the heme region and the high-spin state of heme Fe3+ of Il­DyP4, while Trp380 serves as the surface-exposed radical-forming residue that is closely related to the oxidation of substrates including not only bulky dyes, but also simple phenols. CONCLUSIONS: This study is important for better understanding the catalytic properties of fungal DyPs and their structure-function relationships.

Construction of a combined enzyme system of graphene oxide and manganese peroxidase for efficient oxidation of aromatic compounds.

Manganese peroxidase (MnP) from Irpex lacteus F17 has potential use as a biocatalyst in the field of environmental biotechnology because of its unique properties and ability to decompose harmful aromatic compounds. However, its requirement of harsh acidic reaction conditions and its insufficient catalytic activity restrict its practical applications. Here, we combine graphene oxide (GO) and MnP to construct an efficient enzyme system (GO-MnP) with improved catalytic efficiencies and a wide pH range for the oxidation of aromatic substances and dye decolorization. We found that the Michaelis constant (Km) of GO-MnP for Mn2+ was 2.8 times lower and the catalytic efficiency (kcat/Km) of GO-MnP was 4.5 times higher than those of MnP, and that the decolorization of various dyes by GO-MnP was significantly improved over the pH range of 4.5-5.5. A comparison of the midpoint redox potentials also reflects the strong oxidation ability of GO-MnP. Furthermore, we demonstrated that, in the GO-MnP system, the MnP activity is mainly determined by the amounts of epoxy and carboxyl groups in GO, based on an analysis of the functional group changes in GO and reduced GO associated with different reduction degrees as shown by X-ray photoelectron spectroscopy.

Effects of dietary Cu and Zn on the accumulation, oxidative stress and the expressions of immune-related genes in the livers of Nile tilapia (Oreochromis niloticus).

Excess Cu and Zn can cause many adverse effects in fish. However, few studies have addressed the effects of dietary Cu and Zn on antioxidant physiology and immunity and the underlying mechanisms in fishes. In this study, accumulation of Cu and Zn, effects on the antioxidant enzymes and the transcriptional expressions of immune-related genes were examined in the Oreochromis niloticus fed the Cu and/or Zn enriched duckweed. The results showed that the liver and intestine had the highest accumulation of Cu2+ and Zn2+ while the muscle had the lowest accumulation of these two metals. The activities of SOD, CAT, GPx and the contents of GSH, GSSG in the liver of all treatment groups were significantly decreased compared to the control group. MDA content was significantly elevated in all treatment groups after feeding for 21 days, implying lipid peroxidation in the liver. In the Cu + Zn group, the activities of SOD, GPx and the GSSG content in the liver were significantly decreased. Compared with the Zn group, the LZM activity in the Cu + Zn group was reversed after feeding for 42 days (P < 0.05). The transcriptional expressions of immune-related genes (TNF-α, INF-γ and IL-1ß) in Cu, Zn, Cu + Zn groups were significantly inhibited compared with the control group after treatment for 21 days. Compared with the Cu + Zn group, the level of INF-γ transcripts was significantly reduced in the Cu and Zn group, while the TNF-α expression was elevated after treatment for 42 days. Cu and Zn had synergistic effects on the antioxidant system. Cu has greater effects than Zn on the immunity of O. niloticus. This study demonstrates that dietary Cu and Zn may pose a potential threat to the tilapia populations.

Catalytic properties of a short manganese peroxidase from Irpex lacteus F17 and the role of Glu166 in the Mn2+-independent activity.

Il-MnP1 (GenBank: AGO86670.2) has been confirmed by sequence analysis as a short manganese peroxidase (MnP) from Irpex lacteus F17 (CCTCC AF 2014020). To investigate the catalytic properties, the oxidation of typical aromatic substrates and the pathways of guaiacol oxidation by Il-MnP1, both in the presence and absence of Mn2+ at either pH 4.0 or pH 7.4, were analyzed. Results showed that Il-MnP1 exhibited higher oxidative activity in the presence of Mn2+ than in the absence of Mn2+ toward the majority of the selected substrates at pH 4.0. Additionally, the similar product compositions suggested that the oxidation of guaiacol mainly belongs to a series of polymeric reactions of radicals initiated by Il-MnP1, whether they were in the presence and absence of Mn2+ at either pH 4.0 or 7.4. Furthermore, two variants (E166G, E166Q) were found using site-directed mutagenesis, to improve the Mn2+-independent oxidative activity significantly. The catalytic efficiency (Kcat/Km) of E166G and E166Q in 2, 6-dimethoxyphenol oxidation was higher than Il-MnP1 by 170 and 34 times, respectively. The study revealed certain differences in catalytic properties between Mn2+ dependent and independent oxidation by Il-MnP1. More importantly, a residue (E166) was related to the Mn2+-independent activity of a short MnP.

Loading sulfur and nitrogen co-doped carbon dots onto g-C3N4 nanosheets for an efficient photocatalytic reduction of 4-nitrophenol.

A favorable interface for hybrid photocatalysts makes an important contribution in enhancing photocatalytic reactions. Herein we located sulfur and nitrogen co-doped carbon dots (SN-CDs) onto g-C3N4 nanosheets and achieved a novel SN-CD/g-C3N4 composite with a high visible-light photocatalytic reduction of 4-nitrophenol (4-NP). Compared to g-C3N4 nanosheets, the SN-CD/g-C3N4 composite possessed a wider light absorption. More importantly, the interaction of surface groups led to a favorable interfacial bonding between SN-CDs and g-C3N4 nanosheets, which facilitated the transfer of photoexcited electrons and holes, giving rise to an improved electron transport ability of the composite. In addition, the upward shift of the energy band of g-C3N4 nanosheets due to the location of SN-CDs led to a stronger reducibility of charge carriers. As a consequence, the photocatalytic performance of SN-CD/g-C3N4 has been remarkably improved in the photocatalytic reduction of 4-nitrophenol.

Fabrication of Fe3 O4 Dots Embedded in 3D Honeycomb-Like Carbon Based on Metallo-Organic Molecule with Superior Lithium Storage Performance.

A novel metallo-organic molecule, ferrocene, is selected as building block to construct Fe3 O4 dots embedded in 3D honeycomb-like carbon (Fe3 O4 dots/3DHC) by using SiO2 nanospheres as template. Unlike previously used inorganic Fe3 O4 sources, ferrocene simultaneously contains organic cyclopentadienyl groups and inorganic Fe atoms, which can be converted to carbon and Fe3 O4 , respectively. Atomic-scale Fe distribution in started building block leads to the formation of ultrasmall Fe3 O4 dots (≈3 nm). In addition, by well controlling the feed amount of ferrocene, Fe3 O4 dots/3DHC with well-defined honeycomb-like meso/macropore structure and ultrathin carbon wall can be obtained. Owing to unique structural features, Fe3 O4 dots/3DHC presents impressive lithium storage performance. The initial discharge and reversible capacities can reach 2047 and 1280 mAh g-1 at 0.05 A g-1 . With increasing the current density to 1 and 3 A g-1 , remarkable capacities of 963 and 731 mAh g-1 remain. Moreover, Fe3 O4 dots/3DHC also has superior cycling stability, after a long-term charge/discharge for 200 times, a high capacity of 1082 mAh g-1 can be maintained (80% against the capacity of the 2nd cycle).

Construction of Hierarchically One-Dimensional Core-Shell CNT@Microporous Carbon by Covalent Bond-Induced Surface-Confined Cross-Linking for High-Performance Supercapacitor.

A covalent bond-induced surface-confined cross-linking is reported to construct one-dimensional coaxial CNT@microporous carbon composite (CNT@micro-C). Octaphenyl polyhedral oligomeric silsesquioxane (Ph-POSS) composed of eight phenyls and a -Si8O12 cage was selected as precursor for microporous carbon. The layer-by-layer cross-linking of phenyl anchored Ph-POSS on the surface of CNT; after carbonization and etching of -Si8O12 cages, CNT@micro-C including CNT core and microporous carbon shell was harvested. The thickness of microporous carbon shell can be well tailored from 6.0 to 20.0 nm, and the surface area of CNT@micro-C can reach 1306 m2 g-1. CNT@micro-C combines the structural advantages of CNT and microporous carbon, presenting large surface area, high electrical conductivity, fast ion transfer speed, and short ion transfer distance. When used as electrode material, CNT@micro-C reveals superior supercapacitive performance; for example, its capacitance can reach 243 F g-1 at 0.5 A g-1 and slightly decreases to 209 F g-1 at 10 A g-1, indicating a capacitance retention of 86%. Even at a very high scan rate of 50 A g-1, a high capacitance of 177 F g-1 is retained, giving a capacitance retention of 73%.