The interplay among topology, crystal symmetry, magnetic order, and strong electron correlation can give rise to a plethora of exotic physical phenomena. The ZrSiS family is known as typical topological Dirac semimeta...
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The interplay among topology, crystal symmetry, magnetic order, and strong electron correlation can give rise to a plethora of exotic physical phenomena. The ZrSiS family is known as typical topological Dirac semimetals, among them LnSbTe (Ln denotes lanthanide) compounds exhibit intriguing characteristics due to the presence of Ln 4f electrons, resulting in quantum states and unique properties. In this paper, the topological electronic structure of PrSbTe is systematically studied by angle-resolved photoemission spectroscopy (ARPES), combined with magnetic, specific heat measurements, and band structure calculations. The detailed three-dimensional electronic structure of PrSbTe has been obtained, and a diamond-shaped Fermi surface and multiple Dirac nodal lines have been observed, which are in remarkable agreement with theoretical calculations. Moreover, the 4f electrons in PrSbTe are rather localized, which can be revealed by on-resonant ARPES data and further confirmed by the rather small Sommerfeld coefficient of γ=2.6231mJ/molK2. Our results provide more detailed information about the LnSbTe family, which gives a deeper understanding of the interaction between Ln 4f electrons and the topological states.
Manginoids A-G (1-7), seven monoterpene-shikimate-conjugated meroterpenoids with a spiro ring system, were isolated from Guignardia mangiferae. Compounds 1-4 are four isomers with epimeric and double-bond isomeric fea...
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Manginoids A-G (1-7), seven monoterpene-shikimate-conjugated meroterpenoids with a spiro ring system, were isolated from Guignardia mangiferae. Compounds 1-4 are four isomers with epimeric and double-bond isomeric features possessing a 6-oxaspiro[bicyclo[3.2.1]octane-3,5 '-indene] ring, which represent the first examples of spiro meroterpenoids bearing a bridged spirocyclohexanedione moiety. Compounds 5 and 6 possess an unexpected 2,4-dioxatricyclo[3.3.1.0(3,7)]nonane motif, which fuses with a 6-oxabicyclo[3.2.1]octane moiety. Compound 1 exhibits inhibitory activities against 11 beta-hydroxysteroid dehydrogenase type 1 with an IC50 value of 0.84 mu M.
Circulation of influenza A virus (IAV), especially within poultry and pigs, continues to threaten public health. A simple and universal detecting method is important for monitoring IAV infection in different species. ...
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Circulation of influenza A virus (IAV), especially within poultry and pigs, continues to threaten public health. A simple and universal detecting method is important for monitoring IAV infection in different species. Recently, nanobodies, which show advantages of easy gene editing and low cost of production, are a promising novel diagnostic tool for the monitoring and control of global IAVs. In the present study, five nanobodies against the nucleoprotein of H9N2 IAV were screened from the immunized Bactrian camel by phage display and modified with horseradish peroxidase (HRP) tags. Out of which, we determined that H9N2-NP-Nb5-HRP can crossreact with different subtypes of IAVs, and this reaction is also blocked by positive sera for antibodies against different IAV subtypes. Epitope mapping showed that the nanobody-HRP fusion recognized a conserved conformational epitope in all subtypes of IAVs. Subsequently, we developed a nanobody-based competitive ELISA (cELISA) for detecting anti-IAV antibodies in different species. The optimized amount of coating antigen and dilutions of the fusion and testing sera were 100 ng/well, 1:4000, and 1:10, respectively. The time for operating the cELISA was approximately 35 min. The cELISA showed high sensitivity, specificity, reproducibility, and stability. In addition, we found that the cELISA and hemagglutination inhibition test showed a consistency of 100% and 87.91% for clinical and challenged chicken sera, respectively. Furthermore, the agreement rates were 90.4% and 85.7% between the cELISA and commercial IEDXX ELISA kit. Collectively, our developed nanobody-HRP fusion–based cELISA is an ideal method for monitoring IAV infection in different species.
Arabidopsis WRKY15 functions upstream of VND7, an important regulator of tracheary element (TE) differentiation, to suppress TE formation during plant vascular development. Formation of the vascular cylinder, a struct...
Arabidopsis WRKY15 functions upstream of VND7, an important regulator of tracheary element (TE) differentiation, to suppress TE formation during plant vascular development. Formation of the vascular cylinder, a structure critical to water and nutrient transport in higher plants, is highly regulated. Here we identify WRKY15 as an important regulator that suppresses tracheary element (TE) differentiation in Arabidopsis (Arabidopsis thaliana). Overexpression of WRKY15 resulted in discontinuous protoxylem vessel files and TEs with reduced spiral wall thickening/lignification. Expression of a dominant-negative WRKY15 variant, WRKY15-EAR, led to extra protoxylem vessels and ectopic TEs with increased spiral wall thickening/lignification. Ectopic TE formation in the root cortex and hypocotyl/leaf epidermis reveals that the suppression of WRKY15 is sufficient to trigger the transdifferentiation of other types of cells to TEs. Expression profiling, RT-qPCR, and reporter analyses revealed that WRKY15 suppresses the expression of VASCULAR-RELATED NAC DOMAIN7 (VND7), a master transcriptional regulator that promotes TE differentiation. We propose that WRKY15 negatively regulates VND7 expression indirectly based on (1) the absence of a W-box in the promoter of VND7 and (2) the observation that WRKY15 and VND7 are expressed in different cells in the vascular cylinder, with WRKY15 expressed in the procambial cells and VND7 in the protoxylem poles of procambium and differentiating TEs. Future research is needed to reveal the details underlying the interaction of WRKY15 and VND7 in plant vascular development.
Understanding microbial diversity across different ecosystems is important for discerning the mechanisms shaping the microbial community assembly. However, knowledge on differentiations of microbial diversity in vario...
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Understanding microbial diversity across different ecosystems is important for discerning the mechanisms shaping the microbial community assembly. However, knowledge on differentiations of microbial diversity in various habitats especially engineered systems remains very limited. A comprehensive comparison of microbial diversity across natural and engineered environments, namely heavy metal polluted farm soil, forest, wastewater treatment plants (WWTPs), anaerobic digesters (ADs) and the Caspian Sea sediments, was made base on a collection of 115 samples from seven published 16S rRNA gene datasets generated by high-throughput sequencing. In each sample, 16,590 and 19,771 qualified sequences were detected, and they were classified into 615 to 3,162 operational taxonomic units (OTUs). The microbial communities in the engineered systems especially the AD showed relatively low alpha taxonomic and phylogenetic diversity. A total of 49 genera were present in more than 80% of the samples, accounting for 6.0% in population number and 25.6% in relative abundance (RA). The average abundance-weighted rRNA operon copy number of the communities from ADs and a food wastewater treatment plant (FW) was higher than that of others, suggesting that high loading rate of pollutants in ADs and FW resulted in relatively high abundance of r-strategists. Among 104 typical human bacterial pathogens (HBPs), 2 to 25 HBPs were detected in each sample, accounting for 0.05%-21.34% in RA. Mycobacterium phlei was widely present in 111 samples with an average RA of 0.12%. The number and RA of all the HBPs in each sample did not show an obvious ecosystem type related pattern. Results of detrended correspondence analysis (DCA) and cluster analysis showed that the microbial communities clustered based on habitat types. The communities of WWTPs and soil were very similar, falling into one cluster. For any two communities from the datasets, 75.6% of their beta nearest taxon index (beta NTI) values were h
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