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As functional materials and nano-catalysts, Pd nanoparticles (NPs) are often used to modify two-dimensional (2D) materials. In the heterostructures of metal NPs and 2D transition metal dichalcogenides, the interface atomic configuration and interface effect greatly affect material properties and stability. Therefore, the rational design of interface structures and in-depth analysis of interface interactions are of vital importance for the preparation of specific functional devices. In this work, Pd NPs were deposited on mechanically exfoliated MoS2 flakes and the epitaxial relationship between Pd and MoS2 was observed, accompanied by distinct moiré patterns. Raman spectra of the Pd NPs/MoS2 heterostructure showed an E12g' vibration mode indicative of the local strain in MoS2. A new vibration mode A'1g appeared in the higher-frequency direction compared with the pristine A1g peak. Combined with X-ray photoelectron spectra and density functional theory calculations, the new vibration mode can be attributed to the bonding between Pd and MoS2. Besides, graphene was inserted between Pd NPs and MoS2, and the decoupling of the interfacial effect by graphene was investigated. This study will help deepen our understanding on the interaction mechanism between metals and MoS2, thereby enabling the modulation of optoelectronic properties and the performance of these hybrid materials.
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We introduce a variational formulation for simulating sticky interactions between elastoplastic solids. Our method brings a wider range of material behaviors into the reach of the Incremental Potential Contact (IPC) solver recently developed by [1]. Extending IPC requires several contributions. We first augment IPC with the classical Raous-Cangemi-Cocou (RCC) adhesion model. This allows us to robustly simulate the sticky interactions between arbitrary codimensional-0, 1, and 2 geometries. To enable user-friendly practical adoptions of our method, we further introduce a physically parametrized, easily controllable normal adhesion formulation based on the unsigned distance, which is fully compatible with IPC's barrier formulation. Furthermore, we propose a smoothly clamped tangential adhesion model that naturally models intricate behaviors including debonding. Lastly, we perform benchmark studies comparing our method with the classical models as well as real-world experimental results to demonstrate the efficacy of our method.
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Interfacial atomic configuration and its evolution play critical roles in the structural stability and functionality of mixed zero-dimensional (0D) metal nanoparticles (NPs) and two-dimensional (2D) semiconductors. In situ observation of the interface evolution at atomic resolution is a vital method. Herein, the directional migration and structural evolution of Au NPs on anisotropic ReS2 were investigated in situ by aberration-corrected transmission electron microscopy. Statistically, the migration of Au NPs with diameters below 3 nm on ReS2 takes priority with greater probability along the b-axis direction. Density functional theory calculations suggest that the lower diffusion energy barrier enables the directional migration. The coalescence kinetics of Au NPs is quantitatively described by the relation of neck radius (r) and time (t), expressed as r2=Kt. Our work provides an atomic-resolved dynamic analysis method to study the interfacial structural evolution of metal/2D materials, which is essential to the study of the stability of nanodevices based on mixed-dimensional nanomaterials.
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Diabetic nephropathy (DN) endangers health and is a high financial public burden worldwide. Risk of DN is positively correlated with high levels of reactive oxygen species (ROS). Carnosine, an antioxidant, actively regulates cell function and has the potential to reduce the occurrence of DN. Here, we explored whether carnosine could prevent oxidative stress in human kidney tubular epithelial (HK2) cells and, if so, the mechanisms underlying this effect. HK2 cells were cultured with the ROS hydrogen peroxide (H2O2) for 24 h and then treated with carnosine. In H2O2-damaged HK2 cells, carnosine significantly increased cell viability, assessed using a Cell Counting Kit 8, increased total superoxide dismutase (T-SOD) activity, assessed using a T-SOD activity detection kit, but decreased ROS levels, assessed using a ROS-sensitive fluorescent probe. Western blotting analyses to determine the protein expression levels of BAX, BCL-2, caspase 3, and the NADPH oxidase isoforms NOX2 and NOX4, as well as confocal laser scanning microscopy to assess changes in the mitochondrial membrane potential and the relative position of mitochondria to cytochrome c, indicated that carnosine inhibited apoptosis via the mitochondrial pathway in H2O2-damaged HK2 cells. Significantly decreased NOX4 expression and increased T-SOD activity in the presence of carnosine reduced the production of intracellular ROS, relieving oxidative stress to inhibit apoptosis via the mitochondrial pathway. These findings provide molecular mechanistic insights underlying the effects of carnosine, particularly as a potential therapeutic in DN.
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Carnosina/farmacología , Túbulos Renales Proximales/efectos de los fármacos , Túbulos Renales Proximales/metabolismo , Estrés Oxidativo/efectos de los fármacos , Apoptosis/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Nefropatías Diabéticas/tratamiento farmacológico , Nefropatías Diabéticas/metabolismo , Nefropatías Diabéticas/patología , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Células Epiteliales/patología , Humanos , Peróxido de Hidrógeno/toxicidad , Túbulos Renales Proximales/patología , Potencial de la Membrana Mitocondrial/efectos de los fármacos , NADPH Oxidasa 4/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacos , Superóxido Dismutasa/metabolismoRESUMEN
BACKGROUND: Patients with diabetic cutaneous ulcers experience financial burden and a lower quality of life and life expectancy. Endothelial progenitor cell (EPC)-derived exosomes facilitate skin wound healing by positively modulating vascular endothelial cell function. Exosomes play their important regulatory role through microRNA (miRNA). We explored the potential role and molecular mechanisms of miRNA in EPC-derived exosome healing of diabetic skin wounds. METHODS: Exosomes were isolated from the media of EPCs derived from mice bone marrow. High-throughput sequencing was used to detect the expression of exosome miRNA, and miRNA target genes were predicted using online databases. A diabetic mouse skin wound model was established, and wounds were treated with exosomes, miRNA-221-3p, or phosphate-buffered saline. RESULTS: Exosomes from EPCs accelerated skin wound healing in both control and diabetic mice. High-throughput sequencing showed that miRNA-221-3p was highly expressed in EPC-derived exosomes. Skin wound healing in control and diabetic mice was significantly enhanced by EPC-derived exosomes and miRNA-221-3p administration. Immunohistochemical analyses showed that EPC-derived exosomes and miRNA-221-3p increased protein expression levels of the angiogenesis-related factors VEGF, CD31 and cell proliferation marker Ki67. Bioinformatics analyses indicated that miRNA-221-3p may be involved in the AGE-RAGE signaling pathway in diabetic complications, cell cycle, and the p53 signaling pathway. CONCLUSION: We concluded that miRNA-221-3p is one of the high-expressed miRNAs in EPC-derived exosomes and promoted skin wound healing in diabetic mice. The finding uncovers the molecular mechanism of EPC-derived exosomes and provides a potential novel approach to the clinical treatment of diabetic skin wounds.
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In recent years,the number of patent applications for traditional Chinese medicine( TCM) inventions has increased rapidly,but the authorization rate has declined. Listed TCM enterprises are a group of active innovators in this field,so this paper analyzes their patent quality by combining patent application and authorization with R&D investment of enterprises in order to explore a practical way to improve the quality of TCM patents. The conclusions are as follows: the R&D investment of listed TCM enterprises is insufficient and the gap between enterprises is large; the number of patent applications is within a reasonable range,but some enterprises still have abnormal patent applications,and patent quality needs to be improved; in addition,the patent operation capacity of enterprises still needs to be improved. In this phenomenon,enterprises should improve R&D investment,strengthen the level of technological innovation,improve the ability of patent operation,and consciously eliminate the output of " abnormal patents"; the patent administrative department should optimize policy direction which is beneficial to the improvement of patent quality,grasp the normal and reasonable examination scale,and jointly improve the quality of TCM patents.
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Medicamentos Herbarios Chinos , Medicina Tradicional China , InvencionesRESUMEN
The United States Patent and Trademark Office(USPTO) issued Interim Guidance on Patent Subject Matter Eligibility on December 16ï¼ 2014ï¼ bringing certain effects to the review rules on patent application of Chinese medicine compositions. Based on the Interim Guidanceï¼ cases analysis was used in this paper to analyze the patent subject matter issues of traditional Chinese medicine compositions in the United States. The researches have shown that the application documents should be properly written in the United States when the patent for Chinese medicine compositions is appliedï¼ which can improve the probability of authorization.