Fifteen new diterpenoids, namely xishaklyanes A-O (
-
), along with three known related ones (
-
), were isolated from the soft coral
collected from Xisha Islands, South China Sea. The ...stereochemistry of the new compounds was elucidated by a combination of detailed spectroscopic analyses, chemical derivatization, quantum chemical calculations, and comparison with the reported data. The absolute configuration of compound
was established by the modified Mosher's method for the first time. In bioassay, some of these compounds exhibited considerable antibacterial activities on fish pathogenic bacteria, and compound
showed the most effective activity with MIC of 0.225 μg/mL against
.
Highlights • TLR4 expression was associated with the ability of invasion and migration in HCC. • TLR4 expression contributes to the stem-like properties of HCC cells. • The high expression of TLR4 is ...associated with clinicopathological characteristics and prognosis of HCC.
•This review introduces the molding method of multi-dimensional cellulose materials.•The current scenario of the preparation method of cellulose/carbon composites is summarized.•Applications of ...cellulose/carbon composites in environmental protection are described.•The progress and future potential of composites in water treatment are discussed.
Cellulose, as the most abundant natural polymer material on the earth, has attracted worldwide attention due to its characteristics of reproducibility, universality, low cost, biocompatibility and biodegradability. Cellulose-based materials have potential value in supercapacitors, environment and biomedicine. The combination of cellulose and carbon materials can further adjust the microstructure of the composite such as porosity (76–98.8%) and specific surface area (5.07–47.3 m2/g), and enhance the properties of the composite such as the adsorption rate (47–100%) and the degradation rate of pollutants (60–100%), the Young's modulus (1.14–16.6 GPa) and the tensile strength (23.1–277.5 MPa). Besides, composites have the advantages of high electronic transmission efficiency and good reusability, which broaden their applications in water treatment. This review summarizes the molding methods of multi-dimensional cellulose materials, as well as the development status, preparation and modification methods of composites formed by carbon materials such as graphene, carbon nanotubes, activated carbon and nanodiamonds with cellulose, analyzes the research progress and existing problems of the composites in water treatment fields such as adsorption, catalysis, membrane separation and microbial fuel cells, and finally, we make some perspectives for the future researches and applications.
Two new cembranoids, namely sarcoboettgerols D and E, together with four known related ones, have been isolated from the soft coral Sarcophyton boettgeri collected from Weizhou Island in the South ...China Sea. Their structures including absolute configurations were elucidated by extensive spectroscopic analysis, quantum mechanical nuclear magnetic resonance methods, time‐dependent density functional theory‐electronic circular dichroism calculations, as well as comparison with the reported data in the literature. A plausible biogenetic relationship of four cembranoids was proposed. In bioassays, sarcomililatin B exhibited cytotoxic activity against H1299 cell (IC50=35.0 μM), whereas sarcomililatin B and sarcomililatin A displayed moderate antibacterial activities (MIC 17.4–34.8 μg/mL).
Medium‐entropy (Ti,Zr,Hf)C ceramics were prepared by hot pressing a dual‐phase medium‐entropy carbide powder with low oxygen content (0.45 wt%). The results demonstrate that the medium‐entropy ...(Ti,Zr,Hf)C ceramics sintered at 2100°C had a relative density of 99.2% and an average grain size of 1.9 ± 0.6 μm. The flexural strength of (Ti,Zr,Hf)C carbide ceramics at room temperature was 579 ± 62 MPa. With an increase in temperature to 1600°C, the flexural strength showed an increase up to 619 ± 57 MPa, and had no significant degradation even up to 1800°C. The high‐temperature flexural strengths of (Ti,Zr,Hf)C were obviously higher than those of the monocarbide ceramics (TiC, ZrC, and HfC). The primary strengthening mechanism in (Ti,Zr,Hf)C could be attributed to the high lattice parameter mismatch effects between TiC and ZrC, which not only inhibited the fast grain coarsening of (Ti,Zr,Hf)C ceramics, but also increased the grain‐boundary strength of the obtained ceramics.
Chinese tree shrews (
) have become an increasingly important experimental animal in biomedical research due to their close relationship to primates. An accurately sequenced and assembled genome is ...essential for understanding the genetic features and biology of this animal. In this study, we used long-read single-molecule sequencing and high-throughput chromosome conformation capture (Hi-C) technology to obtain a high-qualitychromosome-scale scaffolding of the Chinese tree shrew genome. The new reference genome (KIZ version 2: TS_2.0) resolved problems in presently available tree shrew genomes and enabled accurate identification of large and complex repeat regions, gene structures, and species-specific genomic structural variants. In addition, by sequencing the genomes of six Chinese tree shrew individuals, we produced a comprehensive map of 12.8 M single nucleotide polymorphisms and confirmed that the major histocompatibility complex (MHC) loci and immunoglobulin gene family exhibited high nucleotide diversity in the tree shrew genome. We updated the tree shrew genome database (TreeshrewDB v2.0: http://www.treeshrewdb.org) to include the genome annotation information and genetic variations. The new high-quality reference genome of the Chinese tree shrew and the updated TreeshrewDB will facilitate the use of this animal in many different fields of research.
A new non-interpenetrated three-dimensional (3D) pillared-layered TPP-based LMOF Zn3(TPyTPP)0.5(BDC)3·8DMF (denoted as Zn-MOF 1) was successfully prepared (TPyTPP = ...tetrakis(4-(pyridin-4-yl)phenyl)pyrazine and H2BDC = 1,4-benzenedicarboxylic acid). Zn-MOF 1 was characterized by single-crystal X-ray diffraction, PXRD, IR, N2 adsorption, thermogravimetric analysis, and luminescent spectrum. Impressively, luminescent sensing studies reveal that activated Zn-MOF 1 not only displays excellent luminescence-quenching efficiency with the values of high K sv and low LODs toward 5-hydroxytryptamine (5-HT) and 5-hydroxyindole-3-acetic acid (5-HIAA), respectively, but also possesses outstanding sensing characteristics in terms of fast response, high sensitivity, and specific selectivity. Zn-MOF 1 performs as efficient sensing of carcinoid biomarkers to provide a fresh detection platform for the diagnosis of carcinoids. In addition, the sensing mechanism was also explored on the basis of ultraviolet–visible (UV–vis) absorption, DFT calculations, and structural analysis.
Currently, many catalysts are inconvenient to separate from water, and the solvents used in the preparation process are not environmentally friendly, resulting in low recovery efficiency and ...secondary pollution. In this study, the magnetic and porous regenerated cellulose/carbon nanotubes/Fe3O4 nanoparticles (RC/CNTs/Fe3O4 NPs) composites were synthesized for activation of peroxydisulfate (PDS) in a green alkaline-urea system. The RC/CNTs/Fe3O4 NPs-PDS system achieved 100% removal of bisphenol A compared with CNTs (~64.6%), RC (~0%) or Fe3O4 NPs (~0%), which was closely related to the introduction of defects and functional groups, nitrogen doping and conductive networks. Interestingly, the strong interaction between CNTs and the sheath-like protective layer formed by urea on the cellulose surface promotes the introduction of nitrogen into the composites at the preparation temperature of 70 °C. Moreover, the mechanism of the system was found to be a typical non-radical pathway. Fortunately, there is no leaching of iron ions in the system, and the effects of the actual waterbody, initial pH, and different anions are negligible. The recycling and separation experiments revealed the practicality and superiority of the composite. This work provides a feasible and sustainable strategy for the application of natural cellulose-supported catalysts.
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•Porous RC/CNTs/Fe3O4 NPs were prepared using natural cellulose as a support.•The catalyst exhibited excellent performance for activating PDS.•The enhanced activity stems from the synergistic effect of cellulose and CNTs.•A way of doping nitrogen with a temperature of 70 °C was discovered.•The non-radical mechanism of RC/CNTs/Fe3O4 NPs-PDS system was proposed.
Among 176 patients who had had severe acute respiratory syndrome (SARS), SARS-specific antibodies were maintained for an average of 2 years, and significant reduction of immunoglobulin G-positive ...percentage and titers occurred in the third year. Thus, SARS patients might be susceptible to reinfection >or=3 years after initial exposure.
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