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Morphine is a widely used opioid for treatment of pain. The attendant problems including morphine tolerance and morphine dependence pose a major public health challenge. In recent years, there has been increasing interest in the gastrointestinal microbiota in many physiological and pathophysiological processes. The connectivity network between the gut microbiota and the brain is involved in multiple biological systems, and bidirectional communication between them is critical in gastrointestinal tract homeostasis, the central nervous system, and the microbial system. Many research have previously shown that morphine has a variety of effects on the gastrointestinal tract, but none have determined the function of intestinal microbiota in morphine tolerance. This study reviewed the mechanisms of morphine tolerance from the perspective of dysregulation of microbiota-gut-brain axis homeostasis, by summarizing the possible mechanisms originating from the gut that may affect morphine tolerance and the improvement of morphine tolerance through the gut microbiota.

Colorectal cancer (CRC) is one of the leading causes of cancer death worldwide, with high morbidity and mortality rates worldwide. Therefore, there is an urgent need to develop more effective treatments for CRC patients. In recent years, there has been some success in the immunotherapy of tumors, and immunotherapy has been used in many solid tumors including CRC. To date, the clinical efficacy of immunotherapy for CRC is limited, so more effective immunotherapy methods need to be explored. In patients with CRC, the CC chemokine CCL5 plays a role in the development of CRC and the recruitment and activation of immune cells, suggesting that it has potential for immunotherapy. This review mainly introduces the latest advances in the study of CCL5 acting as a marker of CRC and related mechanisms of immunotherapy, as well as the latest understanding of how CCL5 is involved in the invasion and development of CRC.

Methamphetamine (METH) is an illegal drug widely abused in many countries. Methamphetamine abuse is a major health and social problem all over the world. However, the effects of METH on the digestive system have rarely been reported. Previous studies and clinical cases have shown that METH use can lead to the impaired intestinal barrier function and severe digestive diseases. METH can cause multiple organ dysfunction, especially in the central nervous system (CNS). The gut microbiota are involved in the development of various CNS-related diseases via the gut-brain axis (GBA). Here, we describe the related effects of METH on the intestinal barrier via cytokines and the underlying mechanisms by which METH may occur in the brain-gut axis.

With rapid development of global marine aquaculture, large amounts of waste shellfish as an aquaculture by-product are generated after consumption. At present, waste seashell powder (WSP) as fillers mixed with polymers is a potentially efficient method to add-value recycle WSP, but the poorly compatibility and seriously agglomeration of WSP results in the low mechanical properties and then reduces the value of recycled shell-based products. In this study, a facile ball-milling exfoliation method with the assistance of polyethyleneimine (PEI) to exfoliate shell materials into high-quality shell nanosheets (SNs) is present. In this case, PEI macromolecular had dual function: it not only acted as a buffer between milling balls and WSP to prevent excessive breaking of the WSP, but also interacted with active bonds on the surface to functionalize the SNs. As a demonstration, the high quality SNs achieve an average lateral size of 414 nm and thickness of 5 nm. Furthermore, the grafting of hydroxyl and amine functional groups onto the SNs, along with the low surface energy of the resulting SNs, has the potential to enhance interfacial interactions with the polymer matrix, thus promoting the overall performance of shell-based composites. This work presents a green and scalable approach for the value-added recycling of waste seashells, offering a sustainable solution to address the environmental impact of aquaculture by-products.

Due to the rare earth supply shortage, ThMn12-type RFe12-based (R is the rare earth element) magnets with lean rare earth content are gaining more concern. Most ThMn12-type RFe12 structures are thermodynamically metastable and require doping of the stabilizing element Ti. However, the Ti-doping effects on the hard magnetic properties of RFe11Ti have not been thoroughly investigated. Herein, based on density functional theory calculations, we report the Ti-doping effects on the phase stability, intrinsic hard magnetic properties and electronic structures of RFe11Ti (R = La, Ce, Pr, Nd, Sm, Y, Zr). Our results indicate that Ti-doping not only increases their phase stability, but also enhances the magnetic hardness of ground-state RFe12 phases. Particularly, it leads to the transition of CeFe11Ti and PrFe11Ti from easy-plane to easy-axis anisotropy. Charge density distributions demonstrate that Ti-doping breaks the original symmetry of the R-site crystal field, which alters the magnetic anisotropy of RFe11Ti. Projected densities of states reveal that the addition of Ti results in the shift of occupied and unoccupied f-electron energy levels of rare earth elements, affecting their magnetic exchange. This study provides an insight into regulating the hard magnetic properties of RFe12-based magnets by Ti-doping.

Interventional catheter is the essential assembly part of interventional therapy. Confronted with complex channels, the catheter suffers from weak mechanical property, high catheter-tissue friction and inferior biocompatibility. Herein, the robust mechanical, lubricated and biocompatible molybdenum disulfide (MoS2)/polypropylene (PPR) catheter was fabricated via flow-directed preferential alignment and fluorination treatment. By rotating the mandrel and die, a dual-directional flow field was constructed and the two-dimensional MoS2 plates aligned preferentially with the planar surface perpendicular to the radial direction of the catheter. Benefiting from the preferential alignment of MoS2 plates, the tensile strength of the rotationally-extruded MoS2/PPR catheter increased by 25.1% compared to the pristine PPR catheter. Furthermore, the direct fluorination treatment was applied to endow the optimized tribology performance and biocompatibility. As a result, the MoS2/PPR catheter with excellent comprehensive performance was prepared by bulk morphology and surface manipulation strategy, which was suitable for industrial scale preparation.

In this paper, the preparation of polypeptides and the synthesis of polypeptide metal chelates from American red fish（Sciaenops ocellatus ）scales were studied and optimized. Polypeptides were prepared from the scales of American red fish. The molecular weight of the peptides was analyzed by gel chromatography. Polypeptide metal chelates were synthesized by water system method and the metal chelating rate was determined by EDTA complexometric titration method. L9(34) orthogonal test was used to optimize the processing conditions of polypeptide metal chelates. The binding of polypeptide to metal was verified by detecting polypeptide and metal chelate by infrared spectroscopy. The molecular weight of polypeptide was about 1~6 kDa by gel chromatography analysis. The preparation conditions of polypeptide zinc chelate were obtained by orthogonal experiment, that is, the mass ratio of zinc chelate was 2:1, pH5.5, temperature 55℃, time 60 min. The optimal chelating conditions were mass ratio 2:1, pH6.0, temperature 35℃ and time 55 min. Under the optimized condition, the chelate ratio of zinc and copper were 78.21% and 91.24% respectively. The infrared absorption spectra showed that Zn2+, Cu2+ and -NH2 were successfully combined. The results showed that the chelation rate was significantly improved under the condition of this process, and it was rich in metal ions, low cost and promising market prospect, which would be conducive to the high-value application of marine fishery processing by-products and promote the technological upgrading of fishery processing industry.

An obese mouse model induced by high-fat diet (HFD) feeding was used to reveal the role of piperine in modulating gut microbiota (GM). Piperine was administrated at 20 and 40 mg/kg body weight every day. As a result, piperine at 40 mg/kg significantly decreased body weight, liver weight, perirenal fat weight, and lowered serum triglycerides, total cholesterol, low-density lipoprotein cholesterol, and glucose levels in HFD-fed mice. Additionally, piperine significantly attenuated fatty liver and modulated hepatic mRNA expressions of SREBP-1c, SREBP2, and HMGCR. In perirenal fat, FAS, C/EBPα, MCP1, and IL-6 expressions were significantly downregulated by piperine. 16S rRNA sequencing revealed that piperine elevated GM diversity. The relative abundance of Muribaculaceae and Ruminococcaceae were significantly elevated, while Dubosiella and Enterorhabdus genera were suppressed by piperine. The Pearson correlation analysis showed that the altered phylotypes were highly correlated with obesity phenotypes. These findings suggest that piperine modulates energy homeostasis and inflammation to alleviate obesity associated with GM regulation.

Flexible piezoelectric devices for energy harvesting have long been attractive in the field of collecting distributed mechanical sources. However, the piezoelectric performance of the state-of-art piezoelectric devices were still limited by poor strain accumulation effect of traditional film or fiber based piezoelectric energy harvesters. Herein, flexible poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF)/barium titanate (BT) three-dimensional (3D) porous composite foam with perfected interface and controlled porosity was prepared via supercritical carbon dioxide (scCO2) foaming technology and surface modification. By manipulating foaming conditions, PVDF foams with uniform cellular structures were successfully obtained. The further introduction of surface coating of polydopamine (PDA) onto BT optimized distribution of BT and foaming behaviors of the composites, and thus by synergetic effect of BT and modulated 3D porous structure, the piezoelectric output was finally improved to ∼12.5 V and ∼150 nA with a peak output power density of ∼0.15 μW/cm2, which was ∼25 times of that of flat-film. Taking advantages of the comprehensive electromechanical performance, the integrated piezoelectric devices can be applied to collect micro sources from use of keyboard and power micro-electronics. Our work provides a simple microstructure design strategy for modulating the porosity to boost the piezoelectric output.

Abstract A novel hybrid flame retardant combining graphene oxide (GO) with long-chain phosphaphenanthrene was fabricated via surface grafting reaction. Taking advantageous of the double barrier effects, including the physical shield contributed by graphene nanoplates during the initial stage and the chemical char contributed by phosphaphenanthrene during the later stage, greatly decreased the release rate of decomposed volatiles from the resin, as well as minimized the release of oxygen and combustion heat. Hence, such hybrid flame retardant can overcome the shortcomings of early acid catalyzed degradation effects caused by conventional flame retardants containing phosphorus. Satisfactory flame retardance was achieved (UL94 V-0 rating) with only 4% addition of the hybrid flame retardant to the epoxy resin laminate. Due to the long-chain and bulky phosphaphenanthrene groups, the interlayer attractive forces of the modified GO were effectively weakened, thus favoring the exfoliation and dispersion of graphene sheets. As a result, the incorporation of the flame retardant slightly enhanced the mechanical properties of the polymer composites, rather than deteriorating them, as occurs with traditional additive flame retardants. As a potential application for graphene, it is believed that the reported hybrid flame retardant has promising future prospect.