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Injectable granular gels consisting of densely packed microgels serving as scaffolding biomaterial have recently shown great potential for applications in tissue regeneration, which allow administration via minimally invasive surgery, on-target cargo delivery, and high efficiency in nutrient/waste exchange. However, limitations such as insufficient mechanical strength, structural integrity, and uncontrollable differentiation of the encapsulated cells in the scaffolds hamper their further applications in the biomedical field. Herein, we developed a new class of granular gels via bottom-up assembly of cell-laden microgels via photo-triggered imine-crosslinking (PIC) chemistry based on the microfluidic technique. The particulate nature of the granular gels rendered them with shear-thinning and self-healing behavior, thereby functioning as an injectable and adaptable cellularized scaffold for bone tissue regeneration. Specifically, single cell-laden, monodisperse microgels composed of methacrylate- and o-nitrobenzene-functionalized hyaluronic acid and gelatin were prepared using a high-throughput microfluidic technique with a production rate up to 3.7 × 108 microgels/hr, wherein the PIC chemistry alleviated the oxygen inhibition on free-radical polymerization and facilitated enhanced fabrication accuracy, accelerated gelation rate, and improved network strength. Further in vitro and in vivo studies demonstrated that the microgels can serve as carriers to support the activity of the encapsulated mesenchymal stem cells; these cell-laden microgels can also be used as cellularized bone fillers to induce the regeneration of bone tissues as evidenced by the in vivo experiment using the rat femoral condyle defect model. In general, these results represent a significant step toward the precise fabrication of engineered tissue mimics with single-cell resolution and high cell-density and can potentially offer a powerful tool for the design and applications of a next generation of tissue engineering strategy. Statement of significance: Using microfluidic droplet-based technology, we hereby developed a new class of injectable and moldable granular gels via bottom-up assembly of cell-laden microgels as a versatile platform for tissue regeneration. Phototriggered imine-crosslinking chemistry was introduced for microgel cross-linkage, which allowed for the fabrication of microgels with improved matrix homogeneity, accelerated gelation process, and enhanced mechanical strength. We demonstrated that the microgel building blocks within the granular gels facilitated the proliferation and differentiation of the encapsulated mesenchymal stem cells, which can further serve as a cellularized scaffold for the treatment of bone defects.

Ultraviolet (UV) visualization has extensive applications in military and civil fields such as security monitoring, space communication, and wearable equipment for health monitoring in the internet of things (IoT). Due to their remarkable optoelectronic features, perovskite materials are regarded as promising candidates for UV light detecting and imaging. Herein, we report for the first time the excitation-dependent perovskite/polymer films with dynamically tunable fluorescence ranging from green to magenta by changing the UV excitation from 260 to 380 nm. And they still render dynamic multi-color UV light imaging with different polymer matrixes, halogen ratios, and cations of perovskite materials. The mechanism of its fluorescence change is related to the chloride vacancies in perovskite materials. A patterned multi-color ultraviolet visualization pad is also demonstrated for visible conversion of the UV region. This technique may provide a universal strategy for information securities, UV visualizations, and dynamic multi-color displays in the IoT.

Background Rapid diagnosis of microbes in the burn wound is a big challenge in the medical field. Traditional biochemical detection techniques take hours or days to identify the species of contaminating and drug-resistant microbes. Near-infrared spectroscopy (NIRS) is evaluated to address the need for a fast and sensitive method for the detection of bacterial contamination in liquids. Methods Herin, we developed a novel technique which by using NIRS together with supporting vector machine (SVM), to identify the microbial species and drug-resistant microbes in LB medium, and to diagnose the wound colonization and wound infection models of pigs. Results The device could recognize 100% of seven kinds of microbes and 99.47% of the multi-drug resistant Staphylococcus aureus (S. aureus), with a concentration of 109 cfu ml−1 in LB medium. The accuracy of the microbial identification in colonized and infected wounds in-situ was 100%. The detection limit of NIRS with SVM for the detection of S. aureus and Escherichia coli (E. coli) was 101 cfu ml−1 in LB medium. Identification time was less than 5 s. Conclusion Our findings validate for the first time a novel technique aimed at the rapid, noncontacted, highly sensitive, and specific recognition of several microbial species including drug-resistant ones. This technique could represent a promising approach to identify diverse microbial species and a potential bedside device to rapidly diagnose infected wounds.

Catalytic methane decomposition (CMD) is a promising route for H2 production. In this paper, MOF-derived hierarchical carbon catalysts were prepared by the carbonization of ZIF-8 with additional carbon source and used for CMD. The effects of carbonization temperature, reaction temperature, and the kinds of additional carbon sources on the structure of derived carbon materials and their catalytic performances were studied. The results showed that the morphology and textural properties can be improved by varying the carbonization temperature and additional carbon source. The specific surface area of the ZIF-derived carbon can be significantly increased, and the hierarchical pore structure with improved pore size distribution can be obtained, which leads to good performances for CMD. Catalytic performance can be obviously enhanced by increasing the reaction temperature. The C950-FA prepared by carbonization of ZIF-8 with furfuryl alcohol as additional carbon source exhibits the highest initial conversion of methane (64%) and good stability at 890 °C. About 11% methane conversion was kept after 2750 min. This study provides a new route for the preparation of carbon material catalysts to achieve high-efficient conversion of methane.

The pathophysiological mechanism underlying Graves' disease (GD) remains incompletely understood. Inhibitory receptors on B cells are critical for humoral immunity, which plays a key role in GD pathogenesis. This study aimed to investigate B cell subsets distribution and inhibitory receptor expression on these subsets in GD patients. Peripheral blood was drawn from 41 healthy controls and 46 GD patients (21 patients with moderate GD, 25 patients with severe GD). B cell subset distribution and CD22, CD32b and CD72 expression on B cells were analyzed by flow cytometry. Serum cytokines were examined by enzyme-linked immunosorbent assay (ELISA). Compared with healthy controls, the naïve B cell percentage was increased, while the preswitched memory and conventional memory B cell percentages were decreased. The inhibitory receptors expression, especially CD32b, on B cell subsets was significantly decreased in patients with GD. In addition, the inhibitory receptors expression on B cell subsets from severe GD patients exhibited a decreasing trend compared with those from moderate GD patients. These results suggest that abnormal B cell subset distribution occurs in GD. Impaired inhibitory receptors, in particular CD32b, play a crucial role in GD pathogenesis and might be a therapeutic target to rebuild self-immune tolerance in GD.

Smooth filtering, a common blurring and denoising operator, has often been utilized postoperatively to diminish the traces left by malicious manipulations. Most of the existing forensic methods only focus on one specific filtering artifact such as median filtering, which is insufficient to reveal the manipulation history of digital images. Unlike traditional convolutional neural network (CNN)-based networks, which normally introduce handcrafted features, including frequency domain features and median filtering residuals, into the preprocessing layer, this paper proposes an end-to-end deep learning model for robust smooth filtering identification. First, a distinctive network structure named the Squeeze-and-Excitation (SE) block is introduced to select discriminative features adaptively and suppress the irrelevant features to the smooth filtering effect. Then, as the network depth increases, multiple inception-residual blocks are stacked to extract discriminative features and reduce the information loss. Finally, different smooth filtering operations can be classified through learning hierarchical features. The experimental results on a composite database show that the proposed model outperforms the state-of-the-art methods, especially in small size and JPEG compression scenarios.

Co-pyrolysis of coke bottle (CB) with sawdust/cellulose/lignin was conducted at 700 °C in this study, aiming to understand the potential influence of interactions of the volatiles of the varied origins on properties of the char. The results indicated that the interaction of volatiles from CB with that from biomass enhanced cross-polymerization of the volatiles, decreasing the formation of gases while enhanced the formation of both char and oil. The cross-interactions of the intermediates also diminished the formation of π-conjugated organics. In addition, the varied volatiles from the pyrolysis of cellulose, lignin, or sawdust interacted with that from CB and affected the properties of char in different ways. The char from the co-pyrolysis of sawdust/CB was more aliphatic, and had a higher oxygen content (7.3%) and higher polarity but lower thermal stability. Additionally, the thermal stability, crystallinity as well as the evolution of functionalities of char versus increasing temperature were also significantly affected by the cross-interactions of the volatiles.