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In this work, we study the mechanisms of X‐ray induced darkening in the Dy/Al/P co‐doped silica glasses at visible wavelengths and explore the role of P/Al ratio played in the enhancement of irradiation resistance. The absorption, emission spectra and lifetime, Raman, and electron paramagnetic resonance spectra of pristine and irradiated Dy‐silica glasses as a function of P/Al ratio were measured and analyzed. The Si‐related defects (Si‐E′ and non‐bridge oxygen hole center), Al‐related defects (Al‐E′ and Al‐related oxygen hole center), P‐related defects (P‐OHC and P2), and Dy2+ ions were studied and analyzed. Results demonstrate that increasing P/Al is efficient to suppress the photodarkening in Dy‐silica glasses at visible wavelengths. Results imply that Dy‐silica glasses with P/Al > 1 may be a promising candidate for efficient visible fiber lasers operated at around 575 nm wavelength. [ABSTRACT FROM AUTHOR]

Endoscopic submucosal dissection (ESD) is one of the most effective approaches for the minimally invasive treatment of early gastrointestinal cancers. Submucosal injections help safely and successfully remove lesions during ESD by elevating the mucosa and separating the submucosal muscle layer. Herein, we report dynamic injectable sodium alginate hydrogels (ISAHs) with shear-thinning for ESD surgery, which were easily fabricated by the sulfhydryl group of GSH-modified sodium alginate (SA-GSH) reacting with the aldehyde group of oxidized sodium alginate (OSA) at room temperature. ISAHs have advantageous self-healing abilities and antioxidant activity. Additionally, according to an in vitro test on porcine colorectal submucosal lifting, the submucosal elevation heights created by ISAHs were 13 % -18 % greater than those created by commercial ESD solutions (0.4 w / v % sodium hyaluronate). These properties and biocompatibility were confirmed in vitro and in vivo experiments. ISAHs will hopefully become a novel submucosal injectable hydrogel to assist ESD surgery. • ISAHs are shear-thinning and can be injected by an endoscopic injection needle. • ISAH have desirable self-healing properties and can effectively elevate lesions. • ISAHs with good antioxidant activity have the potential to reduce the inflammation. • ISAHs have more sustained submucosal lift than the commercial ESD solution. [ABSTRACT FROM AUTHOR]

In this work, we revealed the possible mechanisms of the photodarkening in Pr3+ ions singly doped and Pr3+/Ce3+ co‐doped silicate glasses and fibers induced by X‐ray and 488‐nm laser radiations and studied the role of Ce3+ in increasing radiation resistance in Pr3+‐doped silicate glasses and fibers. The absorption, emission, electron paramagnetic resonance (EPR), radiation induced attenuation spectra, and X‐ray photoelectron spectroscopy (XPS) of Pr3+ singly doped and Pr3+/Ce3+ co‐doped silicate glasses before and after X‐ray radiation were measured and analyzed. The fluorescence intensity and photoinduced attenuation of Pr3+ singly doped and Pr3+/Ce3+ co‐doped silicate fibers at visible wavelengths pumped by 488‐nm laser were measured and analyzed. The influence of Ce3+ ions co‐doping on the spectroscopic properties of Pr3+ ions as well as the radiation‐induced defects in silicate glasses was studied. Results demonstrate that both X‐ray and 488‐nm laser radiations will induce photodamage in Pr3+ ions‐doped silicate glasses and fibers. Co‐doping Ce3+ (by up to 1 mol%) is efficient to suppress the darkening induced by both X‐ray and 488‐nm laser radiations without influence on the luminescence behavior of Pr3+ ions in silicate glasses and fibers. Our studies demonstrate the promising potential of Pr3+/Ce3+ co‐doped silicate glasses for visible lasing applications. [ABSTRACT FROM AUTHOR]

In this study, we explore the photodarkening mechanisms of Tb3+-activated silica, phosphate, fluorophosphate, and fluoride glasses. The glasses were prepared by either conventional melting or sol-gel combined with high temperature sintering. The absorption, emission spectra, lifetime, and electron paramagnetic resonance (EPR) spectra of Tb3+-activated host glasses are systematically characterized before and after X-ray irradiation. The results show that the formation of Tb4+ ions and the oxygen-related hole defects are two key factors which led to the photodarkening in visible region of above glasses after X-ray irradiation. Evaluating from the change of absorption, emission intensity and lifetime at 540 nm, fluoride glass demonstrated a superior photodarkening resistance among four kinds of glasses. It is a preferred host material for lasing operation at visible wavelengths. Our findings offer insight into the photodarkening mechanism of different Tb3+-activated glasses which find applications in fiber lasers at visible wavelengths. • The photodarkening mechanism of Tb3+-activated different glasses was revealed. • Fluoride glass is optimal host material for Tb3+ ion visible laser was certified. • X-ray radiation induced defects in Tb3+-activated different glasses were studied. [ABSTRACT FROM AUTHOR]

• The photodarkening mechanism of Tb3+/Al3+ co-doped silica glasses was revealed. • Influence of Al3+ on optical properties of Tb3+ in silica glasses was studied. • X-ray radiation induced defects in Tb3+/Al3+ co-doped silica glasses were studied. • Valence changes behavior of Tb3+ ions and defects in silica glasses were revealed. In this work, Tb3+/Al3+ co-doped and Al3+ single doped silica glasses are taken as the research objects, and X-ray is used as the simulated light source to study the photodarkening mechanism. Detailed optical properties of the glasses before and after X-ray irradiation and the results of electron paramagnetic resonance (EPR) indicate that the photodarkening effect is attributed to the valence changes of Tb3+ ions and the energy transfer between Tb3+ ions and related defects. In addition, this work revealed the relationship between valence changes behavior of Tb3+ ions and various defects in glass matrix materials, deepening the understanding of the photodarkening mechanism in Tb3+ doped oxide glass. We envisage that our finding provides a depth-theoretical support for the synthesis of Tb3+-doped oxide matrix glass fibers with excellent optical and anti-photodarkening performance. [ABSTRACT FROM AUTHOR]

Tb3+ ions doped optical materials have emerged as gain media for green fiber lasers. Dy3+ ions were proposed as a sensitizer of Tb3+ ions in glasses to increase the excitation efficiency, yet a systematic understanding of the impact of Dy3+ doping on spectroscopic and physiochemical properties of glasses remains lacking. Here, using Tb3+/Dy3+ doped fluoride glass as a model system, we reveal that Dy3+ doping not only enhances Tb3+ emission intensity, but also increases the thermal stability of fluoride glasses. Detailed spectroscopic characterizations indicate that co-doping Dy3+ ions boosts visible luminescence intensity of Tb3+ ions in fluoride glasses due to sensitization of Tb3+ by Dy3+ ions. Importantly, we deeply research the energy transfer process, ascertain several important factors affecting energy transfer efficiency and propose optimal doping concentrations of Tb3+ and Dy3+ ions for visible emission. We envisage that our finding provides a new perspective for the synthesis of Tb3+-doped fluoride glasses with enhanced thermal stability, and may be extended for the fabrication of Tb3+-activated optical fibers. • Much enhanced visible emission of Tb3+ in ZBLAN glass is obtained. • Enhanced thermal stability after co-doping Dy3+ ions is observed. • Effect of sensitizer Dy3+ on visible emissions of Tb3+ ions is studied. • Detailed energy transfer mechanisms between Dy3+ and Tb3+ ions are performed. [ABSTRACT FROM AUTHOR]

Traditional submucosal filling materials frequently show insufficient lifting height and duration during clinical procedures. Here, the anionic polysaccharide polymer sodium carboxymethyl starch and cationic Laponite to prepare a hydrogel with excellent shear-thinning ability through physical cross-linking, so that it can achieve continuous improvement of the mucosal cushion through endoscopic injection. The results showed that the hydrogel (56.54 kPa) had a lower injection pressure compared to MucoUp (68.56 kPa). The height of submucosal lifting height produced by hydrogel was higher than MucoUp, and the height maintenance ability after 2 h was 3.20 times that of MucoUp. At the same time, the hydrogel also showed satisfactory degradability and biosafety, completely degrading within 200 h. The hemolysis rate is as low as 0.76 %, and the cell survival rate > 80 %. Subcutaneous implantation experiments confirmed that the hydrogel showed no obvious systemic toxicity. Animal experiments clearly demonstrated the in vivo feasibility of using hydrogels for submucosal uplift. Furthermore, successful endoscopic submucosal dissection was executed on a live pig stomach, affirming the capacity of hydrogel to safely and effectively facilitate submucosal dissection and mitigate adverse events, such as bleeding. These results indicate that shear-thinning hydrogels have a wide range applications as submucosal injection materials. [Display omitted] [ABSTRACT FROM AUTHOR]

The infection-prone wound pathology microenvironment leads to ulceration and difficult healing of diabetic wounds, which seriously affects the quality of survival of patients. In this study, natural polymer materials gelatin and polylysine were used as substrates. By introducing iron/tannic acid (FeIIITA) composite nanoparticles with excellent photothermal properties into the system, the glutamine residues of gelatin were crosslinked with the primary ammonia of polylysine by glutamine aminotransferase. A nanocomposite hydrogel with excellent antibacterial ability and NO production was constructed it was used to improve the clinical problems of diabetes wounds that were difficult to vascularize and easy to be infected. Under the premise of maintaining its structural stability, the hydrogel can be customized to meet the needs of different mechanical strengths by adjusting the ratios to match different diabetic wounds. Meanwhile, the photothermal effect of FeIIITA nanoparticles can synergize with the endogenous antibacterial ability of polylysine to improve the antibacterial efficacy of hydrogels. The potential of hydrogel to promote intracellular NO production was confirmed by fluorescent staining. Microneedle patches prepared from hydrogel can be applied to diabetic wounds, which can achieve NO deep release. Its anti-inflammatory and angiogenic abilities are also useful in achieving effective healing of diabetic wounds. [Display omitted] • A hydrogel-forming microneedle was designed for diabetic wound healing. • Enzyme-regulated for programmed NO sustained release • Endogenous/photodynamic synergistic and efficient antibacterial • Hydrogel-forming microneedles for deep subcutaneous release of NO • Microneedles promoted collagen deposition, vascular renewal, and anti-inflammatory. [ABSTRACT FROM AUTHOR]

One‐pot transformation of monomer mixtures into block copolymers remains a key challenge. Herein, a metal‐free route to prepare block copolymers from monomer mixtures by a hydroxyl functionalized ionic liquid of 3‐(2‐hydroxyl‐ethyl)‐1‐methylimidazolium bromide (HEMIMB) is described. HEMIMB can bridge two catalytic cycles including ring‐opening alternating copolymerization (ROAC) of phthalic anhydride (PA) with epoxides and ring‐opening polymerization (ROP) of L‐lactide (LA), and enable a selective copolymerization from PA, LA, and epoxides. The selective copolymerization depends on the presence of PA in mixed feedstocks, exhibits the first ROAC of PA with epoxides and then ROP of LA to the formation of block polyesters in one‐pot strategy. This work is beneficial to the development of metal‐free catalysts for sequence‐controlled polymerization that enable block architectures from mixtures of monomers. [ABSTRACT FROM AUTHOR]

In this work, we systematically study the spectroscopic properties of Tb3+/Dy3+ co‐doped phosphate glasses in the visible spectral region and explore the sensitization role of Dy3+ in the enhancement of visible fluorescence of Tb3+ ions. Judd‐Ofelt parameters Ω2 and Ω4/Ω6 of the phosphate glass as host for Tb3+ are calculated as 21.60 × 10‐20 cm2 and 0.73, respectively, based on the measured spectral absorption. Multiple energy transfer (ET) routes from Dy3+ to Tb3+ and their efficiencies are characterized, and the enhanced fluorescence properties of Tb3+ are investigated, including the emission spectral strength and the spontaneous emission lifetime as functions of Dy3+ doping concentration. The efficient nonradiative ET processes between Dy3+ and Tb3+ allow a moderate concentration level of Tb3+ to achieve favorably stronger spectral absorption at blue and ultraviolet wavelengths. Tb3+/Dy3+ co‐doped phosphate glass shows promising potential for phosphors and lasing operation at visible wavelengths. [ABSTRACT FROM AUTHOR]

[Display omitted] • The polysaccharide/protein dual network hydrogel mimics dynamic microenvironment. • Dual antibacterial mechanism reduces endocarditis after valve implantation. • Continuous release of NO and on-demand removal of highly expressed ROS in vivo. • Excellent anti-calcification, anti-inflammation, promote angiogenesis ability. • 3D printing technology to achieve valve structure highly bionic. Heart valve replacement have numerous problems, such as calcification, inflammation, and limited endothelialization. Herein, we used bio-degradable arginine-modified polylysine and oxidized hyaluronic acid as the substrate, expanding the advantages of rapid Schiff-base reaction of aldehydes and amino groups under physiological conditions to form dynamic acyl-hydrazone bonds. These were used to design dynamic adaptive hydrogels, and a polysaccharide/protein dual-network system that mimicked the extracellular matrix, realizing the excellent mechanical tunability and shear thinning properties of its hydrogel. The dual antibacterial mechanism effectively avoided the occurrence of infection-like inflammation after valve implantation. The hydrogel has great ability in promoting cellular proliferation, and can also promote cell migration through a potential cell recruitment mechanism. The hydrogel dynamically triggers and sustains NO release in vivo , removing highly expressed ROS in inflammatory site as needed. It further promotes angiogenesis, and provides targeted treatment for calcified aortic valve disease caused by oxidative stress signals. Furthermore, it exhibits exceptional anti-calcification properties and can enhance the upregulation of CD31 while suppressing the expression of IL-10 and TNF-α, thereby significantly promoting angiogenesis and reducing inflammation. Additionally, 3D printing technology enables the individualized customization of valves with diverse heterogeneous structures to achieve a high degree of biomimetic tissue. [ABSTRACT FROM AUTHOR]