[en] Basic feature of sedimentology and petrology and lithogeochemistry of middle Jurassic Xishanyao formation were discussed for Shihongtan uranium deposit in the paper. The relation between host rock and ore formation was analysed. It is indicated that the formation of Shihongtan uranium deposit de-ponds on the following host features in sedimentology, petrology, lithogeochemistry and the intense oxidized epigenetic alteration under hot dry climate condition during the formation of peneplain caused by the slow tilting uplift. (authors)

[en] Electrospinning technology can easily produce different shaped fibrous structures, making them highly valuable to various biomedical applications. However, surface contamination of biomolecules, cells, or blood has emerged as a significant challenge to the success of electrospun devices, especially artificial blood vessels, catheters and wound dressings etc. Many efforts have been made to resist the surface non-specific biomolecules or cells adsorption, but most of them require complex pre-treatment processes, hard-to-remove metal catalysts or rigorous reaction conditions. In addition, the stability of antifouling coatings, especially in complex conditions, is still a major concern. In this work, inspired by the interpenetrating polymer network and reinforced concrete structure, an efficient and facile strategy for modifying hydrophobic electrospun meshes and tubes with antifouling zwitterionic hydrogels has been introduced. The resulting products could efficiently resist the adhesion of proteins, cells, or even fresh whole blood. Meanwhile, they could maintain the shapes and mechanical strength of the original electrospun structures. Furthermore, the hydrogel structures could retain stable in a physiological condition for at least 3 months. This paper provided a general antifouling and hydrophilicity surface modification strategy for various fibrous structures, and could be of great value for many biomedical applications where antifouling properties are critical. (paper)

[en] An investigation was made into the effect of doping with the elemental crystal Ge or/and GeO_2 on the TiO_2−V_2O_5−Y_2O_3 varistor ceramics. The result shows that as the doping contents of V_2O_5 and Y_2O_3 are 0.5 mol%, respectively, co-doping with 0.3 mol% Ge and 0.9 mol% GeO_2 makes the highest α value (α = 12.8), the lowest breakdown voltage V_1_m_A (V_1_m_A = 15.8 V/mm) and the highest grain boundary barrier Φ_B (Φ_B = 1.48 eV), which is remarkably superior to the TiO_2−V_2O_5−Y_2O_3 varistor ceramics undoped with Ge and GeO_2 and mono-doped with Ge or GeO_2. The TiO_2−V_2O_5−Y_2O_3−Ge−GeO_2 ceramic has the prospect of becoming a novel varistor ceramic with excellent electrical properties. (paper)

[en] The use of implants or indwelling medical devices has greatly enhanced the quality and efficacy of health care. However, foreign-body reactions (FBRs) and infections can lead to potential failure or removal of the devices, or increased morbidity and mortality of patients. Herein, we develop a silver nanoparticle (AgNP) loaded poly(hydroxyethyl methacrylate) hydrogel with spherical, interconnected 40 μm pores. The resulting hydrogels displayed good antibacterial properties regarding both gram positive bacteria (Staphylococcus aureus) and gram negative bacteria (Escherichia coli (E. coli)) in vitro and were highly efficient at inhibiting bacterial cell growth. Moreover, they exhibited an in vivo resistance to FBRs by reducing the immune responses, and completely prevented the formation of collagen capsules. Finally, in vivo studies of the E. coli infected mouse model demonstrated that the AgNP loaded porous hydrogels were highly efficient at resisting the bacterial FBRs and infections, while they promoted cell mitigation and infiltration. Findings from this work suggest that AgNP loaded porous hydrogels hold promise in various biomedical applications including in the new generation of implantable biomedical devices and tissue engineering scaffolds. (paper)

[en] Zwitterionic materials have been attracting significant attentions due to their excellent non-fouling and biocompatible properties and thus have been widely used in many biomedical applications. However, differences among different types of zwitterionic materials have rarely been investigated and compared. In this work, four types of zwitterionic monomers were systematically studied and compared by testing the properties of the hydrogels. Their hydration, diffusion coefficient of water and mechanical properties were evaluated and analyzed. It was found that poly(carboxybetaine methacrylate) (PCBMA) hydrogel possessed the strongest compressive modulus, while poly(carboxybetaine acrylamide) (PCBAA) hydrogel showed the highest diffusion coefficient of water and highest hydration of water. Compared with other hydrogels, the mesh size of poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) hydrogel was the largest. Furthermore, poly(sulfobetaine methacrylate) (PSBMA) hydrogel with disulfide crosslinker degraded faster than the others. Findings in this work provided insights and guidance for the selection of different zwitterionic polymers to suit different applications.

[en] An ultra-sensitive glyphosate nanosensor, based on carbon dots (CDs), was successfully developed with excellent long-wavelength emission (530 nm), a high quantum yield (41.3%), and an impressive detection limit (0.8 ng·mL⁻¹). This is the lowest value for glyphosate detection achieved by CD-based fluorescence analysis. The sensor was derived from a separate precursor, 1,4-dihydroxyanthraquinone, and was based on the “off-on” fluorescence analysis, where Cu²⁺ acts as a dynamic quencher and glyphosate as a fluorescence restorer (excitation wavelength 460 nm). Trace detection of glyphosate is possible with a wide detection range of 50–1300 ng·mL⁻¹ and spiked recoveries between 93.3 and 110.0%. Exploration in depth confirmed that (1) the fluorescence of CDs was derived from the carbon core, (2) the large sp² conjugated domain consisting of graphitic carbon and nitrogen contributed to the long-wavelength emission, and (3) CDs had an impressive binding interaction with Cu²⁺, which endow high sensitivity to glyphosate detection. The nanosensor has also be used as a dual-mode visual sensor and a smart sensing membrane that can identify glyphosate on the surface of vegetables, thus showing good practical applicability.

[en] Highlights: • A biomimetic IVD composite with circumferentially oriented poly(ε-caprolactone) microfibers alginate hydrogel was constructed. • The IVD implants showed progressive tissue formation after subcutaneous implantation in nude mice. • The biomimetic IVD composites have potential application for IVD replacement. -- Abstract: Tissue engineering technology provides a promising alternative to restore physiological functionality of damaged intervertebral disc (IVD). Advanced tissue engineering strategies for IVD have increasingly focused on engineering IVD regions combined the inner nucleus pulposus (NP) and surrounding annulus fibrosus (AF) tissue. However, simulating the cellular and matrix structures and function of the complex structure of IVD is still a critical challenge. Toward this goal, this study engineered a biomimetic AF-NP composite with circumferentially oriented poly(ε-caprolactone) microfibers seeded with AF cells, with an alginate hydrogel encapsulating NP cells as a core. Fluorescent imaging and histological analysis showed that AF cells spread along the circumferentially oriented PCL microfibers and NP cells colonized in the alginate hydrogel similar to native IVD, without obvious migration and mixing between the AF and NP region. Engineered IVD implants showed progressive tissue formation over time after subcutaneous implantation in nude mice, which were indicated by deposition and organization of extracellular matrix and enhanced mechanical properties. In terms of form and function of IVD-like tissue, our engineered biomimetic AF-NP composites have potential application for IVD replacement.

[en] Intervertebral discs (IVDs) are structurally complex tissue that hold the vertebrae together and provide mobility to spine. The nucleus pulposus (NP) degeneration often results in degenerative IVD disease that is one of the most common causes of back and neck pain. Tissue engineered nucleus pulposus offers an alternative approach to regain the function of the degenerative IVD. The aim of this study is to determine the feasibility of porous silk fibroin (SF) scaffolds fabricated by paraffin-sphere-leaching methods with freeze-drying in the application of nucleus pulposus regeneration. The prepared scaffold possessed high porosity of 92.38 ± 5.12% and pore size of 165.00 ± 8.25 μm as well as high pore interconnectivity and appropriate mechanical properties. Rabbit NP cells were seeded and cultured on the SF scaffolds. Scanning electron microscopy, histology, biochemical assays and mechanical tests revealed that the porous scaffolds could provide an appropriate microstructure and environment to support adhesion, proliferation and infiltration of NP cells in vitro as well as the generation of extracellular matrix. The NP cell–scaffold construction could be preliminarily formed after subcutaneously implanted in a nude mice model. In conclusion, The SF porous scaffold offers a potential candidate for tissue engineered NP tissue. - Highlights: • Paraffin microsphere-leaching method is used to fabricate silk fibroin scaffold. • The scaffold has appropriate mechanical property, porosity and pore size • The scaffold supports growth and infiltration of nucleus pulposus cells. • Nucleus pulposus cells can secrete extracellular matrix in the scaffolds. • The scaffold is a potential candidate for tissue engineered nucleus pulposus

[en] Highlights: • Antifouling hydrogel achieved by balancing oppositely charged polyelectrolytes. • Hydrogel can resist protein, bacteria adhesion and induce negligible inflammation. • Hydrogel dressing can rapidly and effectively promote IR-induced injury healing. • Hydrogel dressing is promising for treatment of ionizing radiation-induced injury. Skin injury caused by large doses of ionizing radiation is the common and severe side effect of radiotherapy. However, its therapeutic efficacy is always hindered by early reactive oxygen species generation, repetitive inflammatory microenvironment and bacterial infection risk. Herein, we report an anti-biofouling hydrogel with anti-inflammation and anti-oxidative properties for the treatment of irradiation-induced skin injury. The anti-biofouling hydrogel can be achieved by balancing oppositely charged alginate, hyaluronic acid (HA) and polylysine (PLL) at the optimal ratio, which effectively resist protein and bacterial adhesion, and evades immune response. Moreover, curcumin and epigallocatechin gallate (EGCG) can be facially encapsulated and substantially released from the hydrogel. Results showed that the resulting AHP-Cur/EGCG hydrogel can significantly weaken the development of skin injury and accelerate its healing process by alleviating inflammation, scavenging ROS and promoting angiogenesis. Therefore, the findings presented in this work provide an effective strategy for clinical management and treatment of ionizing radiation-induced skin injury.