1,473 research outputs found

    catena-Poly[[(4-amino­benzoato)aqua­silver(I)]-μ-hexa­methyl­enetetramine]

    Get PDF
    In the title coordination polymer, [Ag(C7H6NO2)(C6H12N4)(H2O)]n, the AgI ion is five-coordinated by two carboxyl­ate O atoms from one 4-amino­benzoate anion (L), two N atoms from two different hexa­methyl­enetetramine (hmt) ligands, and one water O atom in a distorted square-pyramidal geometry. The metal atom lies on a mirror plane and the L anion, hmt ligand and water mol­ecule all lie across crystallographic mirror planes. Each hmt ligand bridges two neighboring AgI ions, resulting in the formation of a chain structure along the b axis. The chains are linked into a three-dimensional framework by N—H⋯O and O—H⋯O hydrogen bonds

    Research progress in targeted therapy for gastric cancer

    Get PDF
    Gastric cancer is a common malignant tumor worldwide, and its incidence rate and mortality have always been in the forefront. Most gastric cancer patients in China are diagnosed in the middle or late stages, with an unsatisfactory 5- year survival rate and poor prognosis. Prior to the emergence of targeted therapy, the combination chemotherapy of fluorouracil and platinum based drugs was considered a first- line treatment option, but the clinical benefits were limited. Targeted therapy, as a current research hotspot and new treatment method in the field of cancer treatment, has been proven by practice, clinical trials, and basic research to significantly improve the survival rate of gastric cancer patients, especially those in the middle and late stages. This article introduces the latest research progress in targeted therapy for gastric cancer, including human epidermal growth factor receptor- 2 (HER2), epidermal growth factor receptor (EGFR), fibroblast growth factor receptor (FGFR), etc., aiming to provide new ideas and directions for targeted therapy for gastric cancer

    The Research of Biology Coupling Characteristics on the Shells of Haliotis discus hannai Ino

    Get PDF
    The surface morphologies, structures and materials of Haliotis discus hannai Ino shells were qualitatively studied by means of a stereoscopic microscope,a field emission scanning electronic microscopy, energy dispersive spectrometer and X-ray diffractometer, and abrasive particle wear was qualitatively and quantitatively studied by means of a pin-on-disc apparatus. The results showed that the outer layer surface of Haliotis discus hannai Ino shells was non-smooth and had some strumae or similar parallel convex wave. The shells of Haliotis discus hannai Ino are polycrystalline composites of calcium carbonate and proteins and glycoproteins and consist of the periostracum, prismatic and nacreous layers with calcite in the outer prismatic layer and aragonite in the inner nacreous layer. Nacreous layer is a natural composite comprised of calcium carbonate in the aragonite polymorph with organic macromolecules sandwiched in between, and the coupling of platelet interlocks and organic materials makes nacreous layer to be strong and tough.The abrasive particle wear tests showed that the abrasion resistance was different on the different parts of the shells, and the left of the shells possessed the highest abrasion resistance and the abrasion resistance of the shells was the lowest on the edge of the right. The nacreous layer possessed higher abrasion resistance than prismatic layer because of the coupling of structure and materials of nacreous layer. Key words: Haliotis discus hannai Ino shells; morphology; structure; materials; anti-wear; biological character; couplin

    Unsupervised Deraining: Where Asymmetric Contrastive Learning Meets Self-similarity

    Full text link
    Most of the existing learning-based deraining methods are supervisedly trained on synthetic rainy-clean pairs. The domain gap between the synthetic and real rain makes them less generalized to complex real rainy scenes. Moreover, the existing methods mainly utilize the property of the image or rain layers independently, while few of them have considered their mutually exclusive relationship. To solve above dilemma, we explore the intrinsic intra-similarity within each layer and inter-exclusiveness between two layers and propose an unsupervised non-local contrastive learning (NLCL) deraining method. The non-local self-similarity image patches as the positives are tightly pulled together, rain patches as the negatives are remarkably pushed away, and vice versa. On one hand, the intrinsic self-similarity knowledge within positive/negative samples of each layer benefits us to discover more compact representation; on the other hand, the mutually exclusive property between the two layers enriches the discriminative decomposition. Thus, the internal self-similarity within each layer (similarity) and the external exclusive relationship of the two layers (dissimilarity) serving as a generic image prior jointly facilitate us to unsupervisedly differentiate the rain from clean image. We further discover that the intrinsic dimension of the non-local image patches is generally higher than that of the rain patches. This motivates us to design an asymmetric contrastive loss to precisely model the compactness discrepancy of the two layers for better discriminative decomposition. In addition, considering that the existing real rain datasets are of low quality, either small scale or downloaded from the internet, we collect a real large-scale dataset under various rainy kinds of weather that contains high-resolution rainy images.Comment: 16 pages, 15 figures. arXiv admin note: substantial text overlap with arXiv:2203.1150

    Study on the efficiency evolution trend of coordinated development of the human–earth system in minority areas of Yunnan, China

    Get PDF
    IntroductionImproving the development efficiency of human–earth systems is a practical requirement for achieving high-quality regional development.MethodsThe article designs a data envelopment analysis (DEA) model under the constraints of coordinated development degree from the perspective of the interaction of natural, economic and social systems to evaluate the development efficiency of human–earth systems and uses GA-BP neural network model for the prediction of the development efficiency of the human–earth system of each geographical unit from 2018 to 2025 based on the panel data of the 8 ethnic autonomous prefectures in Yunnan Province form 1995 to 2017.ResultsThe study found that from 1995 to 2017, the coordination degree and the coordinated development degree of the human–earth system in Yunnan minority areas were on the rise, but mainly manifested in the coordination of low development degree, and the average comprehensive efficiency value of input and output showed a downward trend. The prediction results for 2018–2025 showed that the human–earth system in Yunnan minority areas will be at a low efficient coordinated development level, and the coordinated development degree will show a downward trend. The development degree of natural subsystems in many ethnic minority areas showed negative growth and was negatively correlated with the development degree of economic and social subsystems. In 2025, except Honghe and Banna, the other six regions will be inefficient regions. Among these six inefficient regions, only Wenshan has input redundancy in the natural subsystem, but the phenomenon of input redundancy in the economic subsystem and insufficient output in the natural subsystem is common, indicating that industrial pollution has been controlled to a certain extent in most regions, but the economic investment mode and resource recycling efficiency need to be optimized and improved.DiscussionOur results could enrich the content of human–earth system characteristics in typical regions, and also provide theoretical support for regional coordinated development in China

    Nitrogen loss by anaerobic ammonium oxidation in a mangrove wetland of the Zhangjiang Estuary, China

    Get PDF
    Abstract(#br)Anaerobic ammonium oxidation (anammox), a microbial process in which NH 4 + is oxidized to N 2 gas, is considered a significant nitrogen cycle process, but its significance in mangrove wetland sediments, particularly its depth- and genus-specific distribution and activity have remained uncertain. Here we report the vertical distribution, abundance, activity and role of anammox bacteria in mangrove sediments of Zhangjiang Estuary, China. We used stable isotope-tracer techniques, 16S rRNA and anammox bacterial functional gene (Hydrazine synthase B: hzsB ) clone libraries and quantitative polymerase chain reaction (qPCR) assays, along with an assessment of nutrient profiles of sediment core samples. We observed a widespread occurrence of anammox bacteria at different depths of mangrove sediments. The abundance of anammox bacterial 16S rRNA and hzsB genes ranged from 0.41×10 7 to 9.74×10 7 and from 0.42×10 6 to 6.44×10 6 copies per gram of dry soil and peaked in the upper layer of mangrove sediments. We also verified the co-occurrence of different genera of anammox microorganisms in mangrove sediments, with Candidatus Scalindua and Candidatus Kuenenia being the dominant genera. Potential anammox rates ranged from 4.83 to 277.36 nmolN 2 ·g −1 ·d −1 at different depths of sediment cores, and the highest rates were found in the deeper layer (70–100cm) of mangrove sediments. Scaling our findings up to the entire mangrove system, we estimated that anammox hotspots accounted for a loss of 751 gN·m −2 ·y −1 , and contributed to over 12% of the nitrogen lost from the deeper layer of mangrove sediments in this region

    Nitrogen loss by anaerobic ammonium oxidation in a mangrove wetland of the Zhangjiang Estuary, China.

    Get PDF
    Anaerobic ammonium oxidation (anammox), a microbial process in which NH4+ is oxidized to N2 gas, is considered a significant nitrogen cycle process, but its significance in mangrove wetland sediments, particularly its depth- and genus-specific distribution and activity have remained uncertain. Here we report the vertical distribution, abundance, activity and role of anammox bacteria in mangrove sediments of Zhangjiang Estuary, China. We used stable isotope-tracer techniques, 16S rRNA and anammox bacterial functional gene (Hydrazine synthase B: hzsB) clone libraries and quantitative polymerase chain reaction (qPCR) assays, along with an assessment of nutrient profiles of sediment core samples. We observed a widespread occurrence of anammox bacteria at different depths of mangrove sediments. The abundance of anammox bacterial 16S rRNA and hzsB genes ranged from 0.41×107 to 9.74×107 and from 0.42×106 to 6.44×106 copies per gram of dry soil and peaked in the upper layer of mangrove sediments. We also verified the co-occurrence of different genera of anammox microorganisms in mangrove sediments, with Candidatus Scalindua and Candidatus Kuenenia being the dominant genera. Potential anammox rates ranged from 4.83 to 277.36 nmolN2·g-1·d-1 at different depths of sediment cores, and the highest rates were found in the deeper layer (70-100cm) of mangrove sediments. Scaling our findings up to the entire mangrove system, we estimated that anammox hotspots accounted for a loss of 751 gN·m-2·y-1, and contributed to over 12% of the nitrogen lost from the deeper layer of mangrove sediments in this region

    An emerging research: the role of hepatocellular carcinoma-derived exosomal circRNAs in the immune microenvironment

    Get PDF
    Hepatocellular carcinoma (HCC), the most common primary malignancy of the liver, is one of the leading causes of cancer-related death and is associated with a poor prognosis. The tumor microenvironment (TME) of HCC comprises immune, immunosuppressive, and interstitial cells with hypoxic, angiogenic, metabolic reprogramming, inflammatory, and immunosuppressive features. Exosomes are nanoscale extracellular vesicles that secrete biologically active signaling molecules such as deoxyribonucleic acid (DNA), messenger ribonucleic acid (mRNA), microribonucleic acid (miRNA), proteins, and lipids. These signaling molecules act as messengers in the tumor microenvironment, especially the tumor immunosuppressive microenvironment. Exosomal circRNAs reshape the tumor microenvironment by prompting hypoxic stress response, stimulating angiogenesis, contributing to metabolic reprogramming, facilitating inflammatory changes in the HCC cells and inducing tumor immunosuppression. The exosomes secreted by HCC cells carry circRNA into immune cells, which intervene in the activation of immune cells and promote the overexpression of immune checkpoints to regulate immune response, leading tumor cells to acquire immunosuppressive properties. Furthermore, immunosuppression is the final result of a combination of TME-related factors, including hypoxia, angiogenesis, metabolic reprogramming, and inflammation changes. In conclusion, exosomal circRNA accelerates the tumor progression by adjusting the phenotype of the tumor microenvironment and ultimately forming an immunosuppressive microenvironment. HCC-derived exosomal circRNA can affect HCC cell proliferation, invasion, metastasis, and induction of chemoresistance. Therefore, this review aimed to summarize the composition and function of these exosomes, the role that HCC-derived exosomal circRNAs play in microenvironment formation, and the interactions between exosomes and immune cells. This review outlines the role of exosomal circRNAs in the malignant phenotype of HCC and provides a preliminary exploration of the clinical utility of exosomal circRNAs
    corecore