The first synthesis of MnO@Mn O nanoparticles embedded in an N-doped porous carbon framework (MnO@Mn O /NPCF) through pyrolysis of mixed-valent Mn clusters is reported. The unique features of MnO@Mn O /NPCF are derived from the distinct interfacial structure of the Mn clusters, implying a new methodological strategy for hybrids. The characteristics of MnO@Mn O are determined by conducting high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and electron energy loss spectroscopy (EELS) valence-state analyses. Due to the combined advantages of MnO@Mn O , the uniform distribution, and the NPCF, MnO@Mn O /NPCF displays unprecedented lithium-storage performance (1500 mA h g at 0.2 A g over 270 cycles). Quantitative analysis reveals that capacitance and diffusion mechanisms account for Li storage, wherein the former dominates. First-principles calculations highlight the strong affiliation of MnO@Mn O and the NPCF, which favor structural stability. Meanwhile, defects of the NPCF decrease the diffusion energy barrier, thus enhancing the Li pseudocapacitive process, reversible capacity, and long cycling performance. This work presents a new methodology to construct composites for energy storage and conversion.
As a critical internal RNA modification in higher eukaryotes, N 6-methyladenosine (m 6 A) has become the hotspot of epigenetics research in recent years. Extensive studies on messenger RNAs have revealed that m 6 A affects RNA fate and cell functions in various bioprocesses, such as RNA splicing, export, translation, and stability, some of which seem to be directly or indirectly regulated by noncoding RNAs. Intriguingly, abundant noncoding RNAs such as microRNAs, long noncoding RNAs, circular RNAs, small nuclear RNAs, and ribosomal RNAs are also highly modified with m 6 A and require m 6 A modification for their biogenesis and functions. Here, we discuss the interaction between m 6 A modification and noncoding RNAs by focusing on the functional relevance of m 6 A in cancer progression, metastasis, drug resistance, and immune response. Furthermore, the investigation of m 6 A regulatory proteins and its inhibitors provides new opportunities for early diagnosis and effective treatment of cancer, especially in combination with immunotherapy.
Sodium-ion batteries (SIBs) are considered promising next-generation energy storage devices. However, a lack of appropriate high-performance anode materials has prevented further improvements. Here, a hierarchical porous hybrid nanosheet composed of interconnected uniform TiO nanoparticles and nitrogen-doped graphene layer networks (TiO @NFG HPHNSs) that are synthesized using dual-functional C N nanosheets as both the self-sacrificing template and hybrid carbon source is reported. These HPHNSs deliver high reversible capacities of 146 mA h g at 5 C for 8000 cycles, 129 mA h g at 10 C for 20 000 cycles, and 116 mA h g at 20 C for 10 000 cycles, as well as an ultrahigh rate capability up to 60 C with a capacity of 101 mA h g . These results demonstrate the longest cyclabilities and best rate capability ever reported for TiO -based anode materials for SIBs. The unprecedented sodium storage performance of the TiO @NFG HPHNSs is due to their unique composition and hierarchical porous 2D structure.
Every year, hundreds of new compounds are discovered from the metabolites of marine organisms. Finding new and useful compounds is one of the crucial drivers for this field of research. Here we describe the statistics of bioactive compounds discovered from marine organisms from 1985 to 2012. This work is based on our database, which contains information on more than 15,000 chemical substances including 4196 bioactive marine natural products. We performed a comprehensive statistical analysis to understand the characteristics of the novel bioactive compounds and detail temporal trends, chemical structures, species distribution, and research progress. We hope this meta-analysis will provide useful information for research into the bioactivity of marine natural products and drug development.
Five unique metabolites, xyloketals A (1), B (2), C (3), D (4), and E (5), and the known 6 were isolated from mangrove fungus Xylaria sp. (no. 2508), obtained from the South China Sea. The structures of these compounds were elucidated by spectroscopic and X-ray diffraction experiments. Xyloketal A is a ketal compound with a C(3) symmetry and xyloketals B-E are its analogues. It was found that xytoketal C slowly rearranged to xytoketal B in DMSO-d(6)() solution at room temperature. Xyloketal A exhibited the activity of inhibiting acetylcholine esterase.
Since the 1960s, more than 20,000 compounds were discovered from marine organisms. In this paper we performed a quantitative analysis for the novel marine natural products reported between 1985 and 2008. The data was extracted mainly from the reviews of Faulkner and Blunt [1–26]. The organisms producing these marine natural products are divided into three major biological classes: marine microorganisms (including phytoplankton), marine algae and marine invertebrate. The marine natural products are divided into seven classes based on their chemical structure: terpenoids, steroids (including steroidal saponins), alkaloids, ethers (including ketals), phenols (including quinones), strigolactones, and peptides. The distribution and the temporal trend of these classes (biological classes and chemical structure classes) were investigated. We hope this article provides a comprehensive perspective on the research of marine natural products.
Oncolytic virotherapy is a growing treatment modality that uses replicating viruses as selective antineoplastic agents. Safety and efficacy considerations dictate that an ideal oncolytic agent would discriminate between normal and cancer cells on the basis of common genetic abnormalities in human cancers. Here, we identify a naturally occurring alphavirus (M1) as a novel selective killer targeting zinc-finger antiviral protein (ZAP)-deficient cancer cells. In vitro, in vivo, and ex vivo studies showed potent oncolytic efficacy and high tumor tropism of M1. We showed that the selectivity depends on ZAP deficiency by systematic identification. A large-scale multicenter pathology study using tissue microarrays reveals that ZAP is commonly deficient in human cancers, suggesting extensive application prospects for M1. Additionally, M1 killed cancer cells by inducing endoplasmic reticulum stress-mediated apoptosis. Our report provides novel insights into potentially personalized cancer therapy using oncolytic viruses.
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