Revisited and innovative perspectives of oral ulcer: from biological specificity to local treatment.

Mouth ulcers, a highly prevalent ailment affecting the oral mucosa, leading to pain and discomfort, significantly impacting the patient's daily life. The development of innovative approaches for oral ulcer treatment is of great importance. Moreover, a deeper and more comprehensive understanding of mouth ulcers will facilitate the development of innovative therapeutic strategies. The oral environment possesses distinct traits as it serves as the gateway to the digestive and respiratory systems. The permeability of various epithelial layers can influence drug absorption. Moreover, oral mucosal injuries exhibit distinct healing patterns compared to cutaneous lesions, influenced by various inherent and extrinsic factors. Furthermore, the moist and dynamic oral environment, influenced by saliva and daily physiological functions like chewing and speaking, presents additional challenges in local therapy. Also, suitable mucosal adhesion materials are crucial to alleviate pain and promote healing process. To this end, the review comprehensively examines the anatomical and structural aspects of the oral cavity, elucidates the healing mechanisms of oral ulcers, explores the factors contributing to scar-free healing in the oral mucosa, and investigates the application of mucosal adhesive materials as drug delivery systems. This endeavor seeks to offer novel insights and perspectives for the treatment of oral ulcers.

A hypoxia-activatable theranostic agent with intrinsic endoplasmic reticulum affinity and type-I photosensitivity.

A unique photosensitizer (PS), ERPS, with intrinsic endoplasmic reticulum (ER)-targeting ability and low oxygen-depletion type-I photosensitivity, is developed and used as a scaffold to construct an activatable theranostic agent for precise photodynamic therapy (PDT). The ER-targeted feature coupled with type-I photosensitivity endows ERPS with high phototoxicity toward tumor cells under both normoxic and hypoxic conditions. In addition, caging the phenol group of ERPS with a nitroreductase-sensitive triggering group provided a hypoxia-activatable PS (ERPSIm) that is encapsulated within a polymeric micelle to obtain a water-stable Im@NP nanoparticle for in vivo applications. After intravenous administration to 4T1 tumor-bearing BALB/c mice, Im@NP demonstrated highly efficient imaging-guided PDT ablation of implanted tumors. This is because the delivered ERPSIm cargos of Im@NP are specifically activated in the hypoxic microenvironment of solid tumor, and the activated ERPS molecules have efficient ER-targeted type-I photosensitivity.

Reconfigurable spot size converter for the silicon photonics integrated circuit.

Spot size converter (SSC) plays a role of paramount importance in the silicon photonics integrated circuit. In this article, we report the design of a reconfigurable spot size converter used in the hybrid integration of a DFB laser diode with a silicon photonic waveguide. Our SSC consists of subwavelength gratings and thermal phase shifters. Four subwavelength grating tips are used to improve horizontal misalignment tolerance. Meanwhile, the phase mismatch between two input waveguides is compensated by phase shifters to minimize insertion losses. Our simulated result has yielded a minimum insertion loss of 0.63 dB and an improvement of the horizontal misalignment from ±0.65 µm to ±1.69 µm for 1 dB excess insertion loss at the wavelength of 1310 nm. The phase shifters are designed to compensate any phase error in both the fabrication and bonding processes, which provides a completely new edge-coupling strategy for the silicon photonics integrated circuit.

Core bacterial community driven the conversion of fulvic acid components during composting with adding manganese dioxide.

Here, we revealed the effects of microbes on fulvic acid (FA) formation in composting by adding MnO2. The results showed that the MnO2 promoted the formation of highly humified components (79.2% increased for component 2, and 45.8% increased for component 3) in FA. Additionally, core bacteria involved in FA transformation were identified, the MnO2 increased the relative abundance of core bacteria. Notably, two different core bacteria types were identified: "transforming bacteria" and "processing bacteria". The "transforming bacteria" dominated (about 40% contribution) in the formation of FA components with a high humification degree. The structural equation model confirmed that "transforming bacteria" could convert partly FA components with low humification into highly humified components, and the "transforming bacteria" could be regulated by environmental factors. These findings provided a new insight to manage FA humification degree during composting and helped to improve the application value of FA.

Factoring distinct materials and nitrogen-related microbes into assessments of nitrogen pollution risks during composting.

The aim of this study was to evaluate nitrogen pollution risks from distinct materials composting with the discrepancy of component, including chicken manure, municipal solid and straw waste (CM, MSW, SW). Results showed total nitrogen maximum mean concentrations were observed in CM (39.57 g/kg). Pollution risks in CM were continuous, while MSW and SW mainly concentrated during heating phases. Microbial analysis confirmed that pollution risks from ammonification and nitrification were more prevalent in CM. The risks of pollution caused by nitrate reduction accompanied N2O were the most serious in MSW. The multifunctional nitrogen-related microbes Pseudomonas and Bacillus were affected by microenvironments and contributed to different pollution risks. Furthermore, PICRUSt analysis identified the "inferred" key genes (pmoC-amoC, nrfH, nifD etc.) related to nitrogen pollution risks. This study evaluated nitrogen pollution risks and proposed the future directions, providing theoretical basis and feasible optimization measures for the mitigation of nitrogen pollution during composting.

A Supramolecular Strategy to Engineering a Non-photobleaching and Near-Infrared Absorbing Nano-J-Aggregate for Efficient Photothermal Therapy.

The design of organic photothermal agents (PTAs) for in vivo applications face a demanding set of performance requirements, especially intense NIR-absorptivity and sufficient photobleaching resistance. J-aggregation offers a facile way to tune the optical properties of dyes, thus providing a general design platform for organic PTAs with the desired performance. Herein, we present a supramolecular strategy to build a water-stable, nonphotobleaching, and NIR-absorbing nano-PTA (J-NP) from J-aggregation of halogenated BODIPY dyes (BDP) for efficient in vivo photothermal therapy. Multiple intermolecular halogen-bonding and π-π stacking interactions triggered the formation of BDP J-aggregate, which adsorbed amphiphilic polymer chains on the surface to provide PEGylated sheetlike nano-J-aggregate (J-NS). We serendipitously discovered that the architecture of J-NS was remodeled during a long-time ultrafiltration process, generating a discrete spherical nano-J-aggregate (J-NP) with controlled size. Compared with J-NS, the remodeled J-NP significantly improved cellular uptake efficiency. J-aggregation brought J-NP striking photothermal performance, such as strong NIR-absorptivity, high photothermal conversion efficiency up to 72.0%, and favorable nonphotobleaching ability. PEGylation and shape-remodeling imparted by the polymer coating enabled J-NP to hold biocompatibility and stability in vivo, thereby exhibiting efficient antitumor photothermal activities. This work not only presents a facile J-aggregation strategy for preparing PTAs with high photothermal performance but also establishes a supramolecular platform that enables the appealing optical functions derived from J-aggregation to be applied in vivo.

Halogen Effects-Induced Bright D-π-A Fluorophore as Scaffold for NIR Fluorogenic Probes with High Contrast.

Endowing fluorogenic probes with ultrahigh contrast is essential to increasing the accuracy of fluorescence sensing and imaging. Phenolate-based D-π-A fluorophores (A-DOH) belong to a big family of fluorophores and have attracted increasing attention in fluorogenic probe design. However, the intrinsic dilemma of weak intracellular emission of traditional A-DOH fluorophores resulted in low contrast during live cell imaging. Herein, we present a general and robust approach to preparing novel A-DOH fluorophores with bright NIR fluorescence in living cells based on the unique halogen effects. The reported chlorinated A-DOH fluorophore (A1-2ClOH) has an extremely strong fluorescence in an aqueous solution of pH 7.4 and living cells, which is 194 and 30 times higher than that of the traditional halogen-free analogue (A1-OH), respectively. We systematically investigated and demonstrated that the distinct -I and +M halogen effects, which led to a drastic decrease in the pKa value and a significant enhancement in the fluorescence quantum yield, respectively, should be responsible for the tremendous fluorescence enhancement. The flexible phenol caging chemistry allows one to prepare multiple NIR fluorogenic probes based on the A1-2ClOH scaffold with high contrast for live cell imaging of a variety of analytes by introducing a corresponding triggering moiety. Moreover, the conjugated azide group of A1-2ClOH enables the integration of more functions as desired through a facile click reaction. A fluorogenic probe (mitoProbe-PN) was synthesized as a paradigm by equipping the A1-2ClOH scaffold with a mitochondria-targeting moiety and a peroxynitrite-responsive triggering group and demonstrated specific high-contrast fluorescence imaging of endogenous OONO- in mitochondria of living macrophages.

Universal Scaffold for an Activatable Photosensitizer with Completely Inhibited Photosensitivity.

Activatable photosensitizers (aPSs) sensitive to specific stimuli hold potential for targeting multiple disease biomarkers and are desirable for photodynamic therapy (PDT). Presented herein is the design of aPSs that can be activated and fully recover from an inhibited state in the presence of specific biomarker. A designed long-wavelength D-π-A photosensitizer, PSSe-I , with highly efficient photosensitivity for generation of 1 O2 was used. Caging of the phenolate donor of PSSe-I with a biomarker-sensitive group provided ALP PS, and the drastic activation of its photosensitivity was demonstrated intracellularly. To enhance the flexibility of the design strategy, a clickable azide group was introduced into the scaffold to allow integration of more functionality. Modularly derived mito-PN PS, equipped with a mitochondria-targeting group and a specific peroxynitrite-reactive trigger, was synthesized and demonstrated superior performance in cells. This strategy could lead to customization of aPSs applicable to a specific PDT.

Centimeter-scale 2D perovskite (PEA)2PbBr4 single crystal plates grown by a seeded solution method for photodetectors.

Large-sized single-crystal two-dimensional (2D) perovskites are highly desirable owing to their fundamental properties and intriguing ability to boost devices. Herein, 2-phenylethylammonium lead bromide [(PEA)2PbBr4] single crystals, which are a violet-light-emitting 2D perovskite material, with typical lateral sizes of about one centimeter were successfully grown using a seeded solution method. The single-crystal plates showed a well-defined shape (rectangle or hexagon), a natural thickness (300-500 µm) similar to that of conventional silicon and InP wafers, a large aspect ratio of ∼20, and a smooth surface (root mean square, ∼0.7 nm). We integrated these single crystal plates into an ultraviolet photodetector, achieving a low dark current of ∼10-13 A and an efficient photoresponse (on/off ratio, ∼103). This experiment could easily be extended to grow freestanding 2D perovskite single crystals on a wafer scale for practical integrated optoelectronics.

Low-threshold room-temperature continuous-wave optical lasing of single-crystalline perovskite in a distributed reflector microcavity.

Organic-inorganic halide perovskites have achieved remarkable success in various optoelectronic devices. A high-quality CH3NH3PbBr3 single-crystalline thin film has been directly grown in a micrometer gap between a pair of distributed reflectors with over 99.9% reflectivity, which naturally form a vertical cavity surface-emitting laser device with a single mode or several modes. The single-crystalline perovskite has an exciton lifetime of 426 ns and evidence of the exciton-photon coupling is observed. At room temperature and under continuous-wave optical pumping conditions, this device lases at a threshold of 34 mW cm-2 in the green gap. The extremely low lasing threshold suggests that polariton lasing may occur in the strongly confined optical cavity comprising the high-quality single-crystalline perovskite.

Acetone vapour-assisted growth of 2D single-crystalline organic lead halide perovskite microplates and their temperature-enhanced photoluminescence.

We adopt an acetone vapour-assisted method to grow high quality single-crystalline microplates of two-dimensional (2D) perovskite, 2-phenylethylammonium lead bromide [(C6H5C2H4NH3)2PbBr4]. The microplates, converted from the spin-coated films, are well-defined rectangles. Temperature dependent photoluminescence (PL) spectroscopy shows that the band gap PL is enhanced markedly with increasing temperature up to 218 K, accompanied by the quenching of the PL related to the trap states, which perhaps results from the exciton-phonon couplings. The optical phonon energy around 50 meV and the exciton binding energy around 120 meV are derived by fitting the band gap PL linewidths and intensities at different temperatures, respectively.

A General Strategy Toward Highly Fluorogenic Bioprobes Emitting across the Visible Spectrum.

A general approach toward highly fluorogenic probes across the visible spectrum for various analytes offers significant potential for engineering a wide range of bioprobes with diverse sensing and imaging functions. Here we show a facile and general strategy that involves introducing a new fluorogenic mechanism in boron dipyrromethene (BODIPY) dyes, based on the principle of stimuli-triggered dramatic reduction in the electron-withdrawing capabilities of the meso-substituents of BODIPYs. The fluorogenic mechanism has been demonstrated to be applicable in various BODIPYs with emission maxima ranging from green to far red (509, 585, and 660 nm), and the synthetic strategy allows access to a panel of highly fluorogenic bioprobes for various biomolecules and enzymes (H2O2, H2S, and protease) via introducing specific triggering motifs. The potency of the general design strategy is exemplified by its application to develop a mitochondria-targeting far-red probe capable of imaging of endogenous H2O2 in living cells.

Fully Transparent Quantum Dot Light-Emitting Diode with a Laminated Top Graphene Anode.

A new method to employ graphene as top electrode was introduced, and based on that, fully transparent quantum dot light-emitting diodes (T-QLEDs) were successfully fabricated through a lamination process. We adopted the widely used wet transfer method to transfer bilayer graphene (BG) on polydimethylsiloxane/polyethylene terephthalate (PDMS/PET) substrate. The sheet resistance of graphene reduced to ∼540 Ω/□ through transferring BG for 3 times on the PDMS/PET. The T-QLED has an inverted device structure of glass/indium tin oxide (ITO)/ZnO nanoparticles/(CdSSe/ZnS quantum dots (QDs))/1,1-bis[(di-4-tolylamino)phenyl] cyclohexane (TAPC)/MoO3/graphene/PDMS/PET. The graphene anode on PDMS/PET substrate can be directly laminated on the MoO3/TAPC/(CdSSe/ZnS QDs)/ZnO nanoparticles/ITO/glass, which relied on the van der Waals interaction between the graphene/PDMS and the MoO3. The transmittance of the T-QLED is 79.4% at its main electroluminescence peak wavelength of 622 nm.

Ultrasensitive Near-Infrared Photodetectors Based on a Graphene-MoTe2-Graphene Vertical van der Waals Heterostructure.

Graphene and other layered materials, such as transition metal dichalcogenides, have rapidly established themselves as exceptional building blocks for optoelectronic applications because of their unique properties and atomically thin nature. The ability to stack them into van der Waals (vdWs) heterostructures with new functionality has opened a new platform for fundamental research and device applications. Nevertheless, near-infrared (NIR) photodetectors based on layered semiconductors are rarely realized. In this work, we fabricate a graphene-MoTe2-graphene vertical vdWs heterostructure on a SiO2/p+-Si substrate by a facile and reliable site-controllable transfer method and apply it for photodetection from the visible to NIR wavelength range. Compared to the layered semiconductor photodetectors reported thus far, the graphene-MoTe2-graphene photodetector has a superior performance, including high photoresponsivity (∼110 mA W-1 at 1064 nm and 205 mA W-1 at 473 nm), high external quantum efficiency (EQE; ∼12.9% at 1064 nm and ∼53.8% at 473 nm), rapid response and recovery processes (a rise time of 24 µs and a fall time of 46 µs under 1064 nm illumination), and free from an external source-drain power supply. We have employed scanning photocurrent microscopy to investigate the photocurrent generation in this heterostructure under various back-gate voltages and found that the two Schottky barriers between the graphenes and MoTe2 play an important role in the photocurrent generation. In addition, the vdWs heterostructure has a uniform photoresponsive area. The photoresponsivity and EQE of the photodetector can be modulated by the back-gate (p+-Si) voltage. We compared the responsivities of thin and thick flakes and found that the responsivity had a strong dependence on the thickness. The heterostructure has promising applications in future novel optoelectronic devices, enabling next-generation high-responsivity, high-speed, flexible, and transparent NIR devices.

[A brief analysis on the on-duty systems and dispatching systems in the Imperial Academy of Medicine of the Qing Dynasty].

The "on-duty systems" and "dispatching systems" in the Tai yi yuan (Imperial Academy of Medicine) of the Qing Dynasty served as the "prelude" of the medical officials to carry out their diagnoses and treatments. Mainly serving in the royal court, the "on-duty systems" included 3 sorts, viz., "specially selected on-duty", "interior on-duty" and "exterior on-duty". In addition to providing medical services in the royal court, Imperial Academy of Medicine also served other royal members in the Capital, the ministers, the military, the civilians, the metropolitan examinations and the prisons. Thus, the "dispatching systems" was established, also included 3 sorts, viz., "special dispatchments", "dispatchments through reporting to the emperor" and "dispatchments through official communication".