Search

Purpose: The purpose of this study is to design and implement an intelligent online proctoring system (IOPS) by using the advantage of artificial intelligence technology in order to monitor the online exam, which is urgently needed in online learning settings worldwide. As a pilot application, the authors used this system in an authentic university online exam and checked the proctoring result. Design/methodology/approach: The IOPS adopts the B/S (Browser/Server) architecture. The server side is implemented with programming language C and Python and stores the identification data of all examinees and their important behavior change status, including facial expression, eye and mouth movement and speech. The browser side collects and analyzes multimodal data of the examinee writing the online test locally and transfers the examinee's most important behavior status change data to the server. Real-time face recognition and voice detection are implemented with the support of open-source software. Findings: The system was integrated into a Web-based intelligent tutoring system for school mathematics education. As a pilot application, the system was also used for online proctored exam in an undergraduate seminar in Peking University during the epidemic period in 2020. The recorded log data show that all students concentrated themselves on the exam and did not leave the camera and did not speak. Originality/value: During the epidemic period of the novel coronavirus outbreak, almost all educational institutions in the world use online learning as the best way to maintain the teaching and learning schedule for all students. However, current online instruction platforms lack the function to prevent the learners from cheating in online exams and cannot guarantee the integrity and equality for all examinees as in traditional classroom exams. The literature review shows that the online proctoring system should become an important component of online exams to tackle the growing online cheating problem. Although such proctoring systems have been developed and put on the market, the practical usage of such systems in authentic exams and its effect have not been reported. Those systems are heavyweight and commercial product and cannot be freely used in education. The light-weight IOPS developed by the authors could meet the need for online exam as a stable and practical approach and could contribute to the growing online learning and distance learning.

Background: The complications of large‐volume fat grafting (LVFG) for breast augmentation remain unpredictable and include palpable breast nodules, oil cysts, and calcifications. Aims: This study was aimed to provide an optimal treatment option for breast nodules after LVFG and evaluate their pathological characteristics. Patients/Methods: We effectively performed complete resection of breast nodules in 29 patients after LVFG using a minimal skin incision with the vacuum‐assisted breast biopsy (VABB) system under ultrasound guidance. And we further carried on histologic examination of excised nodules and evaluated their pathological characteristics. Results: The breast nodules were excised thoroughly with cosmetic effect satisfactorily. Interestingly, subsequent histologic examination showed that type I and VI collagens were strongly expressed in the fibrotic area and type IV collagen were positively expressed around the blood vessel. Furthermore, we found that the type VI collagen+ area appeared around mac2+ macrophages and α‐SMA+ myofibroblasts. Conclusions: The VABB system may be the optimal treatment option for breast nodules after LVFG. And type VI collagens may serve as a biomarker of grafted adipose tissue fibrosis. The relationship between macrophages, fibroblasts, and collagen formation may be therapeutic targets for regulating fibrosis. [ABSTRACT FROM AUTHOR]

Background: Skin filler is an option for treating skin aging and wrinkles; however, currently used fillers are limited by poor biocompatibility, rapid degradation, and possible hypersensitivity reactions. Autologous adipose tissue-derived products have been recognized as promising options for skin rejuvenation.Objectives: This study aimed to develop a novel adipose-derived product for skin filling.Methods: Adipose collagen fragment (ACF) was prepared through pulverization, filtration, and centrifugation. The macrography, structure, types of collagen, and cell viability of ACF were evaluated by immunostaining, western blotting, and cell culture assays. ACF, nanofat, and phosphate-buffered saline (9 spots/side, 0.01 mL/spot) were intradermally injected in the dorsal skin of 36 female BALB/c nude mice; the skin filling capacity and the collagen remodeling process were then investigated. Twenty-one female patients with fine rhytides in the infraorbital areas were enrolled and received clinical applications of ACF treatment. Therapeutic effects and patients' satisfaction scores were recorded.Results: The mean [standard deviation] yield of ACF from 50 mL of Coleman fat was 4.91 [0.25] mL. ACF contained nonviable cells and high levels of collagen I, collagen IV, and laminin. Fibroblasts and procollagen significantly increased in ACF and ACF-treated dermis (P < 0.05). Overall, 85.7% of patients were satisfied with the therapy results, and no infections, injection site nodules, or other unwanted side effects were observed.Conclusions: ACF significantly improved dermal thickness and collagen synthesis and may serve as a potential autologous skin filler. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus is a major cause of infectious disease. Macrophages can directly destroy most of the invading bacteria through the phagolysosomal pathway. E74‐like factor 4 (Elf4) is one of the important transcription factors that controls diverse pathogens, but the role of Elf4 in macrophage‐mediated S. aureus eradication is unknown. Our data show that Elf4 is induced by S. aureus in macrophages. Elevated expression of Elf4 results in decreased bacterial load and inflammatory responses during S. aureus infection in vivo and in vitro. Elf4‐overexpressed macrophages have decreased mTOR activity and increased lysosomal mass. Collectively, these results suggest that S. aureus induces Elf4 expression, which enhances lysosomal function and increases the capacity of macrophages to eliminate intracellular pathogens. [ABSTRACT FROM AUTHOR]

The next generation of wearable electronics for health monitoring, Internet‐of‐Things system, "interface‐on‐invisible," and green energy harvesting require electrically conductive material that is superiorly transparent, negligibly hysteretic, industrially feasible, and highly stretchable. The practical potential of ionic hydrogel is challenged with obvious hysteresis and a limited sensing range due to relative delamination and viscoelastic performance. Herein, a novel liquid conductor, termed as egg white liquid, is developed from self‐liquidation of egg white hydrogel, and the liquid not only inherits the designed architecture from a hydrogel predecessor but also achieves comparable conductivity (20.4 S m−1) to the ionic hydrogel and ultrahigh transparency (up to 99.8%). Moreover, the 3D‐printed liquid–elastomer hybrid exhibits excellent conformability, remarkable sensitivity with negligible hysteresis (0.77%), and the capability of monitoring human motions and dynamic moduli is further demonstrated. The liquid nature inspires a gesture‐controlled touchless user interface for front‐end electronic systems. Furthermore, mechanical energy harvesting and pressure sensing are evidenced by exploiting this liquid conductor into a triboelectric nanogenerator. Notably, the as‐prepared liquid via subsequent phase transition possessing superior transparency, ultralow hysteresis, economic benefit, and unique liquid phase may potentially fuel the development of a new class of wearable electronics, human–machine interface, and clean energy. [ABSTRACT FROM AUTHOR]

Chitosan is a promising natural biomaterial for biological application; however, the weak mechanical performance of pristine chitosan limits its further utilization in hard tissue (such as cartilage) engineering. In this study, a chitosan-based 3D printing bioink with suitable mechanical properties was developed as 3D bioprinting ink for chondrocyte support. Chitosan was first modified by ethylenediaminetetraacetic acid (EDTA) to provide more carboxyl groups followed by physical crosslinking with calcium to increase the hydrogel strength. Dynamic mechanical analysis was carried out to evaluate viscoelastic properties with the addition of modified chitosan. A bioink with a combination of modified and pristine chitosan was formulated for scaffold fabrication via 3D bioprinting technique. Furthermore, cell viability, cell proliferation, and expression of chondrogenic markers were evaluated in vitro in chondrocytes loaded on the bioink. The novel bioink exhibited a favorable mechanical property and promoted cell attachment and chondrogenic gene expression in chondrocytes. Based on these results, we can conclude that the presented bioink could qualify for use in 3D bioprinting in cartilage tissue engineering. [ABSTRACT FROM AUTHOR]

Electronic sensors mimicking the function of human skin are promising for the next generation of bionic skin. In this paper, we present a facile and novel approach to prepare an electronic sensor using a physically crosslinked protein hydrogel from egg white with the capability of incorporating conductive nanomaterials. The current strategy led to the formation of extraordinarily stretchable hydrogels in which their shear-thinning and self-healing properties further enabled direct ink writing 3D printing at room temperature, providing novel insights into the biosensor fabrication process. Furthermore, we enhanced the mechanical properties of these hydrogels by introducing secondary physical crosslinking to better resemble human skin. For electronic skin demonstration, a directly 3D printed sensor (EW–CNT sensor) was fabricated with embedding of carbon nanotubes and utilized to capture the delicate wrist pulse, distant reflection of index finger flexion, and respiration as well as vigorous finger bending. Notably, the radial augmentation index and stiffness index of the cardiovascular system could be clearly revealed by the EW–CNT sensor recording. Moreover, the EW hydrogel can be used to fabricate a reversible humidity actuator through a porous gradient architecture. The advantages of the current hydrogel platform including low cost, easy handling, and ease of fabrication for scale-up may open new horizons in the field of epidermal sensors and actuators. [ABSTRACT FROM AUTHOR]

Aim: We investigated the healing effects of conditioned medium (CM) derived from a physiological 3D culture system engineered to use an extracellular matrix/stromal vascular fraction (SVF) gel enriched for adipose on diabetic wounds in rats. This CM (Gel-CM) was compared with that from a 2D culture system that used SVF cells (SVF-CM). Materials & methods: Keratinocytes, fibroblasts and wounds were treated with Gel-CM and SVF-CM, and cytokine levels in the CM types were quantified. Results: Proliferation and migration of keratinocytes and fibroblasts were significantly higher after treatment with Gel-CM than with SVF-CM. Collagen secretion by fibroblasts and wound closure were highly stimulated by Gel-CM. Proteomic analyses revealed a higher concentration of growth factors in Gel-CM than in SVF-CM. Conclusion: Gel-CM is a promising therapeutic option for treating diabetic wounds. [ABSTRACT FROM AUTHOR]

Decellularized adipose tissue (DAT) represents a promising scaffold for adipose tissue engineering. However, the unique and prolonged lipid removal process required for adipose tissue can damage extracellular matrix (ECM) constituents. Moreover, inadequate vascularization limits the recellularization of DAT in vivo. We proposed a neo‐mechanical protocol for rapidly breaking adipocytes and removing lipid content from adipose tissue. The lipid‐depleted adipose tissue was then subjected to a fast and mild decellularization to fabricate high‐quality DAT (M‐DAT). Adipose liquid extract (ALE) derived from this mechanical process was collected and incorporated into M‐DAT to further optimize in vivo recellularization. Ordinary DAT was fabricated and served as a control. This developed strategy was evaluated based on decellularization efficiency, ECM quality, and recellularization efficiency. Angiogenic factor components and angiogenic potential of ALE were evaluated in vivo and in vitro. M‐DAT achieved the same decellularization efficiency, but exhibited better retention of ECM components and recellularization, compared with those with ordinary DAT. Protein quantification revealed considerable levels of angiogenic factors (basic fibroblast growth factor, epidermal growth factor, transforming growth factor‐β1, and vascular endothelial growth factor) in ALE. ALE promoted tube formation in vitro and induced intense angiogenesis in M‐DAT in vivo; furthermore, higher expression of the adipogenic factor PPARγ and greater numbers of adipocytes were evident following ALE treatment, compared with those in the M‐DAT group. Mechanical processing of adipose tissue led to the production of high‐quality M‐DAT and angiogenic factor‐enriched ALE. The combination of ALE and M‐DAT could be a promising strategy for engineered adipose tissue construction. [ABSTRACT FROM AUTHOR]

Autophagy is a highly conserved cellular process that degrades modified, surplus, or harmful cytoplasmic components by sequestering them in autophagosomes which then fuses with the lysosome for degradation. As a major intracellular degradation and recycling pathway, autophagy is crucial for maintaining cellular homeostasis, as well as for remodeling during normal development. Impairment of this process has been implicated in various diseases, in the pathogenic response to bacterial and viral infections, and in aging. Pluripotent stem cells, with their ability to self-replicate and to give rise to any specialized cell type, are very valuable resources for cell-based medical therapies and open a number of promising avenues for studying human development and disease. It has been suggested that autophagy is vital for the maintenance of cellular homeostasis in stem cells, and subsequently more in-depth knowledge about the regulation of autophagy in stem cell biology has been acquired recently. In this review, we describe the most significant advances in the understanding of autophagy regulation in hematopoietic and mesenchymal stem cells, as well as in induced pluripotent stem cells. In particular, we highlight the roles of various autophagy activities in the regulation of self-renewal and differentiation of these stem cells. [ABSTRACT FROM AUTHOR]

Abstract: Conditioned medium (CM) is a new treatment modality in regenerative medicine and has shown a successful outcome in wound healing. We recently introduced extracellular matrix/stromal vascular fraction gel (ECM/SVF‐gel), an adipose‐derived stem cell and adipose native extracellular matrix‐enriched product for cytotherapy. This study aimed to evaluate the effect of CM from ECM/SVF‐gel (Gel‐CM) on wound healing compared with the conventional CM from adipose tissue (Adi‐CM) and stem cell (SVF‐CM). In vitro wound healing effect of three CMs on keratinocytes and fibroblasts was evaluated in terms of proliferation property, migratory property, and extracellular matrix production. In vivo, two full‐thickness wounds were created on the back of each mice. The wounds were randomly divided to receive Gel‐CM, Adi‐CM, SVF‐CM, and PBS injection. Histologic observations and collagen content of wound skin were made. Growth factors concentration in three CMs was further quantified. In vitro, Gel‐CM promoted the proliferation and migration of keratinocytes and fibroblasts and enhanced collagen I synthesis in fibroblasts compared to Adi‐CM and SVF‐CM. In vivo, wound closure was faster, and dermal and epidermal regeneration was improved in the Gel‐CM‐treated mice compared to that in Adi‐CM and SVF‐CM‐treated mice. Moreover, The growth factors concentration (i.e., vascular endothelial growth factor, basic fibroblast growth factor, hepatocyte growth factor, and transforming growth factor‐β) in Gel‐CM were significantly higher than those in Adi‐CM and SVF‐CM. Gel‐CM generated under serum free conditions significantly enhanced wound healing effect compared to Adi‐CM and SVF‐CM by accelerating cell proliferation, migration, and production of ECM. This improved trophic effect may be attributed to the higher growth factors concentration in Gel‐CM. Gel‐CM shows potential as a novel and promising alternative to skin wound healing treatment. But limitations include the safety and immunogenicity studies of Gel‐CM still remain to be clearly clarified and more data on mechanism study are needed. [ABSTRACT FROM AUTHOR]

Autophagy related 16 like 1 (ATG16L1) is a crucial component of autophagy that regulates the formation of the autophagosome. In mammals, ATG16L1 also performs important roles in immunity, including controlling viral replication and regulating innate immune signaling; however, investigation on the role of piscine ATG16L1 in immunity is rare. In this report, the ATG16L1 homolog of black carp Mylopharyngodon piceus (bcATG16L1) was cloned and identified, and its negative regulatory role in mitochondrial antiviral signaling protein (MAVS)-mediated antiviral signaling was described. The coding region of bcATG16L1 consists of 1830 nucleotides and encodes 609 amino acids, including one coiled-coil domain at the N-terminus, three low complexity region domains in the middle, and seven WD40 domains at the C-terminus. By immunofluorescence assay and immunoblotting, we found that bcATG16L1 is a cytosolic protein with a molecular weight of ∼74 kDa. In addition, over-expression of bcATG16L1 suppressed bcMAVS-mediated bcIFNa and DrIFNφ1 promoters transcriptional activity and inhibited bcMAVS-mediated antiviral activity. We further confirmed the co-localization of bcATG16L1 and bcMAVS by immunofluorescence assay and verified the protein interaction between bcATG16L1 and bcMAVS by immunoprecipitation assay. Our results report for the first time that black carp ATG16L1 suppresses MAVS-mediated antiviral signaling in teleost fish. • bcATG16L1 interacts with bcMAVS. • bcATG16L1 suppresses bcMAVS-mediated activation of bcIFNa and DrIFNφ1 promoters. • bcATG16L1 negatively regulates bcMAVS-mediated antiviral activity. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells are an attractive cell type for cytotherapy in wound healing. The authors recently developed a novel, adipose-tissue-derived, injectable extracellular matrix/stromal vascular fraction gel (ECM/SVF-gel) for stem cell therapy. This study was designed to assess the therapeutic effects of ECM/SVF-gel on wound healing and potential mechanisms. ECM/SVF-gel was prepared for use in nude mouse excisional wound healing model. An SVF cell suspension and phosphate-buffered saline injection served as the control. The expression levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and monocyte chemotactic protein-1 (MCP-1) in ECM/SVF-gel were analyzed at different time points. Angiogenesis (tube formation) assays of ECM/SVF-gel extracts were evaluated, and vessels density in skin was determined. The ECM/SVF-gel extract promoted tube formation in vitro and increased the expression of the angiogenic factors VEGF and bFGF compared with those in the control. The expression of the inflammatory chemoattractant MCP-1 was high in ECM/SVF-gel at the early stage and decreased sharply during the late stage of wound healing. The potent angiogenic effects exerted by ECM/SVF-gel may contribute to the improvement of wound healing, and these effects could be related to the enhanced inflammatory response in ECM/SVF-gel during the early stage of wound healing. [ABSTRACT FROM AUTHOR]

Transparent Protein Hydrogels: Protein Gel Phase Transition: Toward Superiorly Transparent and Hysteresis-Free Wearable Electronics (Adv. Funct. Keywords: gesture-controlled consoles; hysteresis-free sensors; phase transition; transparent protein hydrogels; triboelectric nanogenerators EN gesture-controlled consoles hysteresis-free sensors phase transition transparent protein hydrogels triboelectric nanogenerators 1 1 1 07/04/20 20200702 NES 200702 In article number 1910080, Feng Lu, Malcolm Xing, and co-workers report a solid-liquid phase transition from egg white hydrogel; the resulting transparent liquid can be employed as an electric conductor for wearable electronics, and is hysteresis-free and velocity-insulating. Gesture-controlled consoles, hysteresis-free sensors, phase transition, transparent protein hydrogels, triboelectric nanogenerators. [Extracted from the article]

Correction for 'Hydrogels from natural egg white with extraordinary stretchability, direct-writing 3D printability and self-healing for fabrication of electronic sensors and actuators' by Qiang Chang et al., J. Mater. Chem. A, 2019, DOI: 10.1039/c9ta06233e. [ABSTRACT FROM AUTHOR]

Interferon regulatory factor 3 (IRF3) is activated by IκB kinase ε (IKKε) and Tank-binding kinase 1 (TBK1), which plays a crucial role in the interferon signaling in vertebrates. However, the regulation of teleost IRF3 by IKKε remains largely unknown. In this study, the IRF3 homologue (bcIRF3) of black carp (Mylopharyngodon piceus) has been cloned and characterized. The transcription of bcIRF3 was detected to increase in host cells in response to different stimuli. bcIRF3 distributed predominantly in the cytosolic area; however, translocated into nuclei after virus infection. bcIRF3 showed IFN-inducing ability in reporter assay and EPC cells expressing bcIRF3 showed enhanced antiviral ability against both grass carp reovirus (GCRV) and spring viremia of carp virus (SVCV). Moreover, knockdown of bcIRF3 reduced the antiviral ability of the host cells, and the transcription of antiviral-related cytokines was obviously lower in bcIRF3-deficient host cells than that of control cells. The data of reporter assay and plaque assay demonstrated that bcIKKε obviously enhanced bcIRF3-mediated IFN production and antiviral activity. Immunofluorescent staining and co-immunoprecipitation assay revealed that bcIKKε interacted with bcIRF3. It was interesting that the nuclear translocation of bcIRF3 and bcIKKε was enhanced by each other when these two molecules were co-expressed in the cells, however, the protein levels of bcIRF3 and bcIKKε were decreased mutually. Thus, our data support the conclusion that bcIKKε interacts with bcIRF3 and enhances bcIRF3-mediated antiviral signaling during host innate immune activation. • bcIKKε interacted with bcIRF3 and enhanced bcIRF3/IFN signaling. • The nuclear translocation of bcIRF3 and bcIKKε was enhanced by each other when co-expressed. • Knockdown of bcIRF3 led to the dampened antiviral activity of the host cells. [ABSTRACT FROM AUTHOR]

Xenotransplantation of acellular adipose matrix (AAM) has come to prominence as an intriguing option for soft tissue reconstruction. However, the presence of immunogenic antigens within AAM can trigger unfavorable immune reactions, leading to inadequate in vivo regeneration outcomes. Therefore, the development of advanced technology capable of modulating immune responses is crucial for the therapeutic implementation of AAM xenografts. In this work, an innovative technique is created to bypass the immune system by covering the surface of both AAM and Arg-Gly-Asp (RGD) peptide-modified AAM xenografts with autologous red blood cell (RBC) membrane. The RBC membrane coating remained persistent and exhibited no significant decline even after 21 days. Moreover, it effectively reduced the expression of antigen major histocompatibility complex class 1 (MHC1) on the AAM surface. Following xenogeneic transplantation, the RBC-coated xenografts demonstrated increased expression of the adipogenic factor PPAR-γ , Adipoq , Fabp4 , Fasn, and Plin1 and higher numbers of adipocytes. In addition, they exhibited decreased expression of immunological factors, including IL-6, IL-2 , IFN-γ , and TNF-α , and fewer inflammatory cells. These findings indicate that RBC membrane coating successfully suppressed immune responses and promoted increased adipogenesis in AAM xenografts. Therefore, AAM camouflage coating with RBC has a lot of potential as a biomaterial for soft tissue reconstruction in clinical settings.