Survey on blockchain-based non-fungible tokens: History,technologies, standards,and open challenges

This paper presents a survey of non-fungible tokens (NFTs), including its history, technologies, standards, and challenges in their development. An NFT is a unique digital entity that is created and maintained using blockchain technology. Each NFT is identified using a unique smart contract and a token ID, so the whole history of the NFT can be globally identified by its address and token ID. The blockchain information indelibly identifies the current owner of any asset, previous owners, and original creator. NFTs are used to manage ownership of digital and physical assets and cryptocurrencies. The prices of popular NFTs have become very high, and the market for them has overheated in recent years. NFT technology and its ecosystem have evolved since Quantum, the first NFT, was stored in the Namecoin blockchain. Ethereum has become the main platform for NFT projects because it provides support for smart contracts. Currently, almost all NFT projects are launched on the Ethereum blockchain. NFT has two major standards called ERC-721 and ERC-1155, which have had important functions in the development of NFT. Starting with these two standards, other standards for NFT continue to emerge; they expand the functionality of NFT such as by adding utility. However, NFT is a very early technology, and it has not been long after the NFT concept was created and used. So there are several challenges for further improving NFT technology, in terms of usability, interoperability, and evolution. This paper presents a survey of NFT, including its history, technologies, standards, and challenges of NFT.     

Morphological core/shell structure and dispersion stability of water-dispersible copolyester graft polymerized with acrylic acid and ethyl acrylate

Anionic water-dispersible copolyester was prepared by the polycondensation of dimethyl isophathalate (DMI)/5-sodium sulfo dimethyl isophathalate (DMS) with ethylene glycol (EG)/ diethylene glycol (DEG) to synthesize water-dispersible copolyester-g-AA/EAs by chemical method. In the case of graft polymerization of AA/EA onto DMI/DMS/EG/DEG copolyester does not. This is a result of the core/shell structure that was ascertained by the graft yield and the zeta potential of copolyester-g-AA/EAs. It appears that grafted AA/EA exists at the surface of copolyester-g-AA/EA particles, and the backbone polymer, i.e., DMI/DMS/EG/DEG copolyester, exists in the inner phase of the copolyester, -g-AA/EA particles. The complete solubility of copolyester-g-AA/EAs in 1N NaOH aqueous solution seems to come mainly from the electrostatic repulsion between  COOs that are present at the surface of copolyester-g-AA/EA particles due to AA grafting and  OHs that are present at the dispersion medium due to NaOH decomposition and which cause the hydrolytic breakage and consequently the coagulation of copolyesters in alkaline medium. © 1996 John Wiley & Sons, Inc.     

Dietary Mannan Oligosaccharides Modulate Gut Microbiota,Increase Fecal Bile Acid Excretion,and Decrease Plasma Cholesterol and Atherosclerosis Development

1 Scope

Mannan oligosaccharides (MOS) have proven effective at improving growth performance, while also reducing hyperlipidemia and inflammation. As atherosclerosis is accelerated both by hyperlipidemia and inflammation, we aim to determine the effect of dietary MOS on atherosclerosis development in hyperlipidemic ApoE*3‐Leiden.CETP (E3L.CETP) mice, a well‐established model for human‐like lipoprotein metabolism.

2 Methods and results

Female E3L.CETP mice were fed a high‐cholesterol diet, with or without 1% MOS for 14 weeks. MOS substantially decreased atherosclerotic lesions up to 54%, as assessed in the valve area of the aortic root. In blood, IL‐1RA, monocyte subtypes, lipids, and bile acids (BAs) were not affected by MOS. Gut microbiota composition was determined using 16S rRNA gene sequencing and MOS increased the abundance of cecal Bacteroides ovatus. MOS did not affect fecal excretion of cholesterol, but increased fecal BAs as well as butyrate in cecum as determined by gas chromatography mass spectrometry.

3 Conclusion

MOS decreased the onset of atherosclerosis development via lowering of plasma cholesterol levels. These effects were accompanied by increased cecal butyrate and fecal excretion of BAs, presumably mediated via interactions of MOS with the gut microbiota.     

Minimally processed ready-to-eat baby-leaf vegetables: Production,processing, storage,microbial safety,and nutritional potential

The market for minimally processed ready-to-eat (RTE) baby-leaf vegetables (BLVs) has been rapidly growing and offering to consumers convenient and appealing products, rich in health beneficial bioactive compounds. These vegetables are harvested at a very early stage of maturation and prepared with minimal processing methods such as cutting, washing, rinsing, and packaging with the modified atmosphere of O₂, CO₂, and relative humidity (RH). Maintenance of microbial safety, color, texture, aroma, and nutrients are the major problems associated with commercial production and marketing of BLVs. This review discusses the theoretical aspects and recent developments in the maintenance of nutritional quality and microbial safety during production, processing, sanitization, packaging, and storage of BLVs. The varietal improvements in BLVs for wider adaptability and disease resistance are also discussed. Additionally, future research challenges in these contexts are identified.     

Piezoelectric Microvibration Mitigates Estrogen Loss-Induced Osteoporosis and Promotes Piezo1, MicroRNA-29a,and Wnt3a Signaling in Osteoblasts

Biophysical stimulation alters bone-forming cell activity, bone formation and remodeling. The effect of piezoelectric microvibration stimulation (PMVS) intervention on osteoporosis development remains uncertain. We investigated whether 60 Hz, 120 Hz, and 180 Hz PMVS (0.05 g, 20 min/stimulation, 3 stimulations/week for 4 consecutive weeks) intervention affected bone integrity in ovariectomized (OVX) mice or osteoblastic activity. PMVS (120 Hz)-treated OVX mice developed fewer osteoporosis conditions, including bone mineral density loss and trabecular microstructure deterioration together with decreased serum resorption marker CTX-1 levels, as compared to control OVX animals. The biomechanical strength of skeletal tissue was improved upon 120 Hz PMVS intervention. This intervention compromised OVX-induced sparse trabecular bone morphology, osteoblast loss, osteoclast overburden, and osteoclast-promoting cytokine RANKL immunostaining and reversed osteoclast inhibitor OPG immunoreactivity. Osteoblasts in OVX mice upon PMVS intervention showed strong Wnt3a immunoreaction and weak Wnt inhibitor Dkk1 immunostaining. In vitro, PMVS reversed OVX-induced loss in von Kossa-stained mineralized nodule formation, Runx2, and osteocalcin expression in primary bone-marrow stromal cells. PMVS also promoted mechanoreceptor Piezo1 expression together with increased microRNA-29a and Wnt3a expression, whereas Dkk1 rather than SOST expression was repressed in MC3T3-E1 osteoblasts. Taken together, PMVS intervention promoted Piezo1, miR-29a, and Wnt signaling to upregulate osteogenic activity and repressed osteoclastic bone resorption, delaying estrogen deficiency-induced loss in bone mass and microstructure. This study highlights a new biophysical remedy for osteoporosis.     

土聚水泥技术在飞灰资源化中的应用

固体废物焚烧处理技术在我国日益得到推广应用,这导致我国垃圾焚烧飞灰产量巨大.垃圾焚烧飞灰中含有浸出毒性较高的重金属,属危险废弃物.但飞灰中含有丰富的活性组分,可以作为合成材料的原料而加以综合利用.飞灰基土聚水泥作为一种新型碱激活胶凝材料,可以大大降低飞灰中重金属的浸出毒性,同时具有较高的抗压强度.本文在介绍土聚水泥聚合机理的基础上,从飞灰预处理、外加硅铝原料的添加、碱激发剂浓度和掺量、水灰比、骨料、养护条件等方面阐述了对飞灰基土聚水泥强度和重金属浸出毒性的影响,最后对飞灰基土聚水泥重金属浸出毒性方面研究提出了建议.     

Antioxidant properties of 1,2,3,4,6-penta-O-galloyl-β-d-glucose from Elaeocarpus sylvestris var. ellipticus

The antioxidant potential of 1,2,3,4,6-penta-O-galloyl-β-d-glucose (PGG), isolated from Elaeocarpus sylvestris var. ellipticus, was investigated by various established systems based on cell-free and cell system experiments, such as radical detection, antioxidant enzyme assay, lipid peroxidation detection, and cell viability assay. PGG was found to quench the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and intracellular reactive oxygen species. PGG recovered the cellular antioxidant enzyme activities of superoxide dismutase, catalase, and glutathione peroxidase, which were reduced by H₂O₂ treatment, thereby resulting in the inhibition of lipid peroxidation. Cytoprotective effects of PGG were based on the results of DNA fragmentation, mitochondrial membrane potential (Δψ), apoptotic body formation, and caspase-3 activity. The results suggest that PGG protects cells against H₂O₂-induced cell damage via antioxidant properties.     

Effect of Neferine on DNCB-Induced Atopic Dermatitis in HaCaT Cells and BALB/c Mice

Atopic dermatitis (AD) is a chronic and persistent inflammatory skin disease characterized by eczematous lesions and itching, and it has become a serious health problem. However, the common clinical treatments provide limited relief and are accompanied by adverse effects. Therefore, there is a need to develop novel and effective therapies to treat AD. Neferine is a small molecule compound isolated from the green embryo of the mature seeds of lotus (Nelumbo nucifera). It has a bisbenzylisoquinoline alkaloid structure. Relevant studies have shown that neferine has many pharmacological and biological activities, including anti-inflammatory, anti-thrombotic, and anti-diabetic activities. However, there are very few studies on neferine in the skin, especially the related effects on inflammatory skin diseases. In this study, we proved that it has the potential to be used in the treatment of atopic dermatitis. Through in vitro studies, we found that neferine inhibited the expression of cytokines and chemokines in TNF-α/IFN-γ-stimulated human keratinocyte (HaCaT) cells, and it reduced the phosphorylation of MAPK and the NF-κB signaling pathway. Through in vivo experiments, we used 2,4-dinitrochlorobenzene (DNCB) to induce atopic dermatitis-like skin inflammation in a mouse model. Our results show that neferine significantly decreased the skin barrier damage, scratching responses, and epidermal hyperplasia induced by DNCB. It significantly decreased transepidermal water loss (TEWL), erythema, blood flow, and ear thickness and increased surface skin hydration. Moreover, it also inhibited the expression of cytokines and the activation of signaling pathways. These results indicate that neferine has good potential as an alternative medicine for the treatment of atopic dermatitis or other skin-related inflammatory diseases.