Abstract Acellular porcine corneal stroma (APCS) has been proven to maintain the matrix microenvironment and is therefore an ideal biomaterial for the repair and reconstruction of corneal stroma. ...This study aims to develop a method to prepare cosmetic corneal lens implants for leukoma using genipin-crosslinked APCS (Gc-APCS). The Gc-APCS was prepared from APCS immersed in 1.0% genipin aqueous solution (pH 5.5) for 4 h at 37 °C, followed by lyophilization at −10 °C. The color of the Gc-APCS gradually deepened to dark-blue. The degree of crosslinking was 45.7 ± 4.6%, measured by the decrease of basic and hydroxy amino acids. The porous structure and ultrastructure of collagenous lamellae were maintained, and the porosity and BET SSA were 72.7 ± 4.6% and 23.01 ± 3.45 m2 /g, respectively. The Gc-APCS rehydrated to the physiological water content within 5 min and was highly resistant to collagenase digestion. There were no significant differences in the areal modulus and curvature variation between Gc-APCS and nature porcine cornea. The dark-blue pigments were stable to pH, light and implantation in vivo . Gc-APCS extracts had no inhibitory effects on the proliferation of keratocytes. Corneal neovascularization, graft degradation and corneal rejection were not observed within 6 months.
Developing scaffolds with appropriate mechanical/structural features as well as tunable bioactivities are indispensable in the field of tissue engineering. This study focused on one such attempt to ...electrospin the copolymer of L-lactic acid (L-LA) and functional monomer (3(S)- (benzyloxycarbony)methyl-1,4-dioxane-2,5-dione, BMD) with small peptide modifications for the purpose of neural tissue engineering. Scanning Electron Microscopy (SEM) micrographs showed fabricated electrospun copolymer as porous and uniform nanofibrous materials with diameter in the range of 800-1000 nm. In addition, the modified scaffolds displayed a lower contact angle than poly(L-lactide) (PLLA) indicating higher hydrophilicity. To further incorporate the bioactive functions, the nanofibers were chemically coupled with small peptide (isoleucine-lysine-valine-alanine-valine, IKVAV). The incorporation of IKVAV onto the electrospun fiber was confirmed by X-ray photoelectron spectroscopy (XPS) and such incorporation did not affect the surface morphology or fiber diameters. To demonstrate the potential of applying the designed scaffolds for nerve regeneration, dorsal root ganglion (DRG) neurons were cultured on the nanofibers to examine the impact on neurite outgrowth of DRGs. The results indicated that the fabricated nanofibrous matrix with small peptide might be a potential candidate for neural tissue engineering.
We developed a fixation method and evaluate bone regrowth in the cavities of a Ф4 mm× 8 mm titanium（Ti）tube through porous hydroxyapatite（HAP）/β-tricalcium phosphate（β-TCP）composite filling（group ...A）,chitosan/calcium phosphate composite filling（group B）,and HAP particle modification（group C）.After 2 and 5 months of implantation in dog tibia defects,new bone formation in the three groups was studied by histology and histomorphometry.Group A displayed the most bone regenerated area in both 2 and 5 months post-operation.The chitosan/calcium phosphate composite in group B mostly degraded 2 months after implantation,leading to fibrous tissue invasion after 5 months.By contrast,less bone formation was observed in group C.These results indicated that filling the cavities of metalprostheses with a porous HAP/β-TCP composite can be used for stable long-term fixation in clinicalsettings.
Traumatic bronchial rupture in infants usually necessitates surgical intervention, with few reports documenting instances of multiple cardiac arrests occurring during surgery under conditions of ...severe hypoxemia.
A 3-year-old boy after trauma presented with severe hypoxemia for 2 days and was urgently transferred to the operating room for surgery, 6 episodes of cardiac arrest happend during surgery.
The baby was diagnosed with bronchial rupture based on the history of trauma, clinica manifestations, and intraoperative findings.
Intrathoracic cardiac compression and intravenous adrenaline were administrated.
The normal sinus rhythm of the heart was successfully restored within 1 minute on each occasion, facilitating the smooth completion of the surgical procedure. By the end of surgery, SpO2 levels had rebounded to 95% and remained stable.
Inadequate management of bronchial ruptures in infants frequently coincides with severe hypoxemia, necessitating immediate surgical intervention. Prompt identification and management of cardiac arrest by anesthetists during surgery is imperative to reduce mortality.
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nanoprobes prepared by laser ablation in liquid can be used as magnetic resonance imaging contrast agent. However, their immunotoxicity in vivo remains unknown. In this article, the in vitro ...biocompatibility of the Gd
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nanoprobe was evaluated in terms of cell uptake, cell viability, and apoptosis. In vivo immunotoxicity was detected by monitoring the levels of the immunity mediator, cluster of differentiation (CD) markers in Balb/c mice. The results show that no in vitro cytotoxicity was observed, and no significant changes in the expression levels of CD206 and CD69 between the nanoprobe-injected group and the Gd-DTPA group in mice were observed. Importantly, the immunotoxicity data revealed significant differences in the expression levels of CD40, CD80, CD11b, and reactive oxygen species. In addition, transmission electron microscopy images showed that few Gd
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nanoprobes were localized in phagosomes by the endocytic pathway. In conclusion, the toxic effects of our Gd
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nanoprobe may be due to endocytosis during which the microstructure or ultrastructure of cells is slightly damaged and induces the generation of an oxidative stress reaction that further stimulates the innate immune response. Therefore, it is important to use a sensitive assay for the in vivo immunotoxicity measurements to evaluate the risk assessment of Gd
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We have successfully synthesized SiO2@(Y0.5Gd0.45Eu0.05)2O3 nanocomposites as a potential dual-modality nanoprobe for molecular imaging in vitro. However, their immunotoxicity assessment in vivo ...remains unknown. In this article, the in vitro biocompatibility of our dual-modality nanoprobes was assayed in terms of cell viability and apoptosis. In vivo immunotoxicity was investigated by monitoring the generation of reactive oxygen species (ROS), cluster of differentiation (CD) markers and cytokines in Balb/c mice. The data show that the in vitro biocompatibility was satisfactory. In addition, the immunotoxicity data revealed there are no significant changes in the expression levels of CD11b and CD71 between the nanoprobe group and the Gd in a diethylenetriaminepentaacetic acid (DTPA) chelator (Gd-DTPA) group 24 h after injection in Balb/c mice (p>0.05). Importantly, there are significant differences in the expression levels of CD206 and CD25 as well as the secretion of IL-4 and the generation of ROS 24 h after injection (p<0.05). Transmission electron microscopy (TEM) images showed that few nanoprobes were localized in the phagosomes of liver and lung. In conclusion, the toxic effects of our nanoprobes may mainly result from the aggregation of particles in phagosomes. This accumulation may damage the microstructure of the cells and generate oxidative stress reactions that further stimulate the immune response. Therefore, it is important to evaluate the in vivo immunotoxicity of these rare earth-based biomaterials at the molecular level before molecular imaging in vivo.
The structure of, and transitions between, liquids, crystals and glasses have commonly been studied with the hard-sphere model, in which the atoms are modelled as spheres that interact only through ...an infinite repulsion on contact. Suspensions of uniform colloidal polymer particles are good approximations to hard spheres, and so provide an experimental model system for investigating hard-sphere phases. They display a crystallization transition driven by entropy alone. Because the particles are much larger than atoms, and the crystals are weakly bound, gravity plays a significant role in the formation and structure of these colloidal crystals. Here we report the results of microgravity experiments performed on the Space Shuttle Columbia to elucidate the effects of gravity on colloidal crystallization. Whereas in normal gravity colloidal crystals grown just above the volume fraction at melting show a mixture of random stacking of hexagonally close-packed planes (r.h.c.p.) and face-centred cubic (f.c.c.) packing if allowed time to settle,, those in microgravity exhibit the r.h.c.p. structure alone, suggesting that the f.c.c. component may be induced by gravity-induced stresses. We also see dendritic growth instabilities that are not evident in normal gravity, presumably because they are disrupted by shear-induced stresses as the crystals settle under gravity. Finally, glassy samples at high volume fraction which fail to crystallize after more than a year on Earth crystallize fully in less than two weeks in microgravity. Clearly gravity masks or alters some of the intrinsic aspects of colloidal crystallization.
With the increasing number of ships on the sea, the frequency multi-ship encounters situation was becoming more common than two-ship encounter. The complexity and risk of the navigation will ...exponentially increase with the more ships involved. Relying solely on the International Regulations for Preventing Collisions at Sea (COLREGS) (objective knowledge) was insufficient to handle the multi-ship intelligent collision avoidance problem, also needed the ship officer's good seamanship (subjective knowledge). In this study, we propose a methodology that combines subjective insights from AIS big data with objective analysis through multi-ship encounters recognition with graph convolutional networks (GCN). (1) The ship encounter 8-azimuths map was utilized to identify the two-ship encounter situation (25 types) from the AIS data. (2) Identify the multi-ship encounters trajectory data by cross-matching the two-ship encounter data. (3) To handle the intricate relationship information between the multiple ships which were transformed into a graph structure using graph theory. (4) Finally, a spatial-temporal edge and node attention graph convolutional network (ST-ENAGCN) was proposed with the graph convolutional unit and long short-term memory (LSTM) unit. The 2022 Ningbo Sea area AIS big data was utilized to achieve graph-structured learning regarding human experiences during the multi-ship encounters situation. The results indicate that the ST-ENAGCN model can understand the complex marine traffic situation to make the own ship collision avoidance decisions. This study contributes significantly to the increased efficiency and safety of sea operations in complex marine traffic conditions and support autonomous navigation of swarm of MASSs under the human-machine hybrid (HMH) conditions to better understand the collision avoidance intention of the ship officer in the multi-ship encounters situation.
•The ship encounter 8-azimuths map was utilized to extract the data of 25 types of two-ships encounter modes from the AIS big data. Identify the multi-ships encounter trajectory data by cross-matching the two-ships encounter data.•The intricate relationships information between the multi-ship were transformed into a graph structure using graph theory.•A spatial temporal edge and node attention graph convolutional networks was proposed with the edge and node attention graph convolutional unit and long short-term memory unit, that was utilized to achieve graph structured learning regarding human experiences during the multi-ships encounter situation.
Neuroinflammation following peripheral surgery is a pivotal pathogenic mechanism of postoperative cognitive dysfunction (POCD). However, the key site of inflammation-mediated neural damage remains ...unclear. Impaired mitochondrial function is a vital feature of degenerated neurons. Dynamin-related protein 1 (DRP1), a crucial regulator of mitochondrial dynamics, has been shown to play an essential role in synapse formation. Here, we designed experiments to assess whether Drp1-regulated mitochondrial dynamics and function are involved in the pathological processes of POCD and elucidate its relationship with neuroinflammation. Aged mice were subjected to experimental laparotomy under isoflurane anesthesia. Primary neurons and SH-SY5Y cells were exposed to tumor necrosis factor (TNF). We found an increase in Drp1 activation as well as mitochondrial fragmentation both in the hippocampus of mice after surgery and primary neurons after TNF exposure. Pretreatment with Mdivi-1, a Drp1 specific inhibitor, reduced this mitochondrial fragmentation. Drp1 knockdown with small interfering RNA blocked TNF-induced mitochondrial fragmentation in SH-SY5Y cells. However, the application of Mdivi-1 exhibited a negative impact on mitochondrial function and neurite growth in primary neurons. Calcineurin activity was increased in primary neurons after TNF exposure and contributed to the Drp1 activation. The calcineurin inhibitor FK506 exhibited a Drp1-independent function that mitigated mitochondrial dysfunction. Finally, we found that FK506 pretreatment ameliorated the neurite growth in neurons treated with TNF and the learning ability of mice after surgery. Overall, our research indicated a crucial role of mitochondrial function in the pathological processes of POCD, and neuronal metabolic modulation may represent a novel and important target for POCD.
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•Drp1-mediated mitochondrial fission involved in the pathological processes of POCD.•Mitochondrial dysfunction occurred prior to fission under TNF stimulation.•Inhibiting fission worsened mitochondrial function and neural outcome.•Calcineurin mediated Drp1 activation in response to TNF stimulation.•Calcineurin inhibition may be a potential therapeutic strategy for POCD.
Electrical stimulation can facilitate wound healing with high efficiency and limited side effects. However, current electrical stimulation devices have poor conformability with wounds due to their ...bulky nature and the rigidity of electrodes utilized. Here, a flexible electrical patch (ePatch) made with conductive hydrogel as electrodes to improve wound management was reported. The conductive hydrogel was synthesized using silver nanowire (AgNW) and methacrylated alginate (MAA), with the former chosen as the electrode material considering its antibacterial properties, and the latter used due to its clinical suitability in wound healing. The composition of the hydrogel was optimized to enable printing on medical-grade patches for personalized wound treatment. The ePatch was shown to promote re-epithelization, enhance angiogenesis, mediate immune response, and prevent infection development in the wound microenvironment. In vitro studies indicated an elevated secretion of growth factors with enhanced cell proliferation and migration ability in response to electrical stimulation. An in vivo study in the Sprague-Dawley rat model revealed a rapid wound closure within 7 days compared to 20 days of usual healing process in rodents.
A flexible electrical patch (ePatch) with conductive hydrogel was designed to accelerate wound healing. The conductive hydrogel contains silver nanowire and methacrylated alginate, which endow antibacterial efficacy and printability to the ePatch. Healing speed was promoted in a Sprague Dawley rat-based wound model. Display omitted
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