138 research outputs found
Synthesis and systematic evaluation of dark resonance energy transfer (DRET)-based library and its application in cell imaging
10.1002/asia.201403257Chemistry - An Asian Chemistry103581-58
Dark to light! A new strategy for large Stokes shift dyes: coupling of dark donor with tunable high quantum yield acceptors
10.1039/c4sc01821dChemical Science5124812-481
Discovery of 21 New Changing-look AGNs in Northern Sky
The rare case of changing-look (CL) AGNs, with the appearance or
disappearance of broad Balmer emission lines within a few years, challenges our
understanding of the AGN unified model. We present a sample of 21 new CL AGNs
at , which doubles the number of such objects known to date. These
new CL AGNs were discovered by several ways, from (1) repeat spectra in the
SDSS, (2) repeat spectra in the Large Sky Area Multi-Object Fiber Spectroscopic
Telescope (LAMOST) and SDSS, and (3) photometric variability and new
spectroscopic observations. We use the photometric data from surveys, including
the SDSS imaging survey, the Pan-STARRS1, the DESI Legacy imaging survey, the
Wide-field Infrared Survey Explorer (WISE), the Catalina Real-time Transient
Survey, and the Palomar Transient Factory. The estimated upper limits of
transition timescale of the CL AGNs in this sample spans from 0.9 to 13 years
in the rest frame. The continuum flux in the optical and mid-infrared becomes
brighter when the CL AGNs turn on, or vice versa. Variations of more than 0.2
mag in band were detected in 15 CL AGNs during the transition. The optical
and mid-infrared variability is not consistent with the scenario of variable
obscuration in 10 CL AGNs at more than confidence level. We confirm a
bluer-when-brighter trend in the optical. However, the mid-infrared WISE colors
become redder when the objects become brighter in the band,
possibly due to a stronger hot dust contribution in the band when the AGN
activity becomes stronger. The physical mechanism of type transition is
important for understanding the evolution of AGNs.Comment: Accepted for publication in Ap
The C-terminal motif of SiAGO1b is required for the regulation of growth, development and stress responses in foxtail millet (\u3ci\u3eSetaria italica\u3c/i\u3e (L.) P. Beauv)
Foxtail millet (Setaria italica (L.) P. Beauv), which belongs to the Panicoideae tribe of the Poaceae, is an important grain crop widely grown in Northern China and India. It is currently developing into a novel model species for functional genomics of the Panicoideae as a result of its fully available reference genome sequence, small diploid genome (2n=18, ~510 Mb), short life cycle, small stature and prolific seed production. Argonaute 1 (AGO1), belonging to the argonaute (AGO) protein family, recruits small RNAs and regulates plant growth and development. Here, we characterized an AGO1 mutant (siago1b) in foxtail millet, which was induced by ethyl methanesulfonate treatment. The mutant exhibited pleiotropic developmental defects, including dwarfing stem, narrow and rolled leaves, smaller panicles and lower rates of seed setting. Map-based cloning analysis demonstrated that these phenotypic variations were attributed to a C–A transversion, and a 7-bp deletion in the C-terminus of the SiAGO1b gene in siago1b. Yeast two-hybrid assays and BiFC experiments revealed that the mutated region was an essential functional motif for the interaction between SiAGO1b and SiHYL1. Furthermore, 1598 differentially expressed genes were detected via RNAseq- based comparison of SiAGO1b and wild-type plants, which revealed that SiAGO1b mutation influenced multiple biological processes, including energy metabolism, cell growth, programmed death and abiotic stress responses in foxtail millet. This study may provide a better understanding of the mechanisms by which SiAGO1b regulates the growth and development of crops
The C-terminal motif of SiAGO1b is required for the regulation of growth, development and stress responses in foxtail millet (\u3ci\u3eSetaria italica\u3c/i\u3e (L.) P. Beauv)
Foxtail millet (Setaria italica (L.) P. Beauv), which belongs to the Panicoideae tribe of the Poaceae, is an important grain crop widely grown in Northern China and India. It is currently developing into a novel model species for functional genomics of the Panicoideae as a result of its fully available reference genome sequence, small diploid genome (2n=18, ~510 Mb), short life cycle, small stature and prolific seed production. Argonaute 1 (AGO1), belonging to the argonaute (AGO) protein family, recruits small RNAs and regulates plant growth and development. Here, we characterized an AGO1 mutant (siago1b) in foxtail millet, which was induced by ethyl methanesulfonate treatment. The mutant exhibited pleiotropic developmental defects, including dwarfing stem, narrow and rolled leaves, smaller panicles and lower rates of seed setting. Map-based cloning analysis demonstrated that these phenotypic variations were attributed to a C–A transversion, and a 7-bp deletion in the C-terminus of the SiAGO1b gene in siago1b. Yeast two-hybrid assays and BiFC experiments revealed that the mutated region was an essential functional motif for the interaction between SiAGO1b and SiHYL1. Furthermore, 1598 differentially expressed genes were detected via RNAseq- based comparison of SiAGO1b and wild-type plants, which revealed that SiAGO1b mutation influenced multiple biological processes, including energy metabolism, cell growth, programmed death and abiotic stress responses in foxtail millet. This study may provide a better understanding of the mechanisms by which SiAGO1b regulates the growth and development of crops
Valley-polarized Exitonic Mott Insulator in WS2/WSe2 Moir\'e Superlattice
Strongly enhanced electron-electron interaction in semiconducting moir\'e
superlattices formed by transition metal dichalcogenides (TMDCs) heterobilayers
has led to a plethora of intriguing fermionic correlated states. Meanwhile,
interlayer excitons in a type-II aligned TMDC heterobilayer moir\'e
superlattice, with electrons and holes separated in different layers, inherit
this enhanced interaction and strongly interact with each other, promising for
realizing tunable correlated bosonic quasiparticles with valley degree of
freedom. We employ photoluminescence spectroscopy to investigate the strong
repulsion between interlayer excitons and correlated electrons in a WS2/WSe2
moir\'e superlattice and combine with theoretical calculations to reveal the
spatial extent of interlayer excitons and the band hierarchy of correlated
states. We further find that an excitonic Mott insulator state emerges when one
interlayer exciton occupies one moir\'e cell, evidenced by emerging
photoluminescence peaks under increased optical excitation power. Double
occupancy of excitons in one unit cell requires overcoming the energy cost of
exciton-exciton repulsion of about 30-40 meV, depending on the stacking
configuration of the WS2/WSe2 heterobilayer. Further, the valley polarization
of the excitonic Mott insulator state is enhanced by nearly one order of
magnitude. Our study demonstrates the WS2/WSe2 moir\'e superlattice as a
promising platform for engineering and exploring new correlated states of
fermion, bosons, and a mixture of both
Calcium Supplementation Enhanced Adipogenesis and Improved Glucose Homeostasis Through Activation of Camkii and PI3K/Akt Signaling Pathway in Porcine Bone Marrow Mesenchymal Stem Cells (pBMSCs) and Mice Fed High Fat Diet (HFD)
Background/Aims: It has been implicated that calcium supplementation is involved in reducing body weight/fat and improving glucose homeostasis. However, the underlying mechanisms are still not fully understood. Here, we investigated the effects of calcium supplementation on adipogenesis and glucose homeostasis in porcine bone marrow mesenchymal stem cells (pBMSCs) and high fat diet (HFD)-fed mice and explored the involved signaling pathways. Methods: In vitro, pBMSCs were treated with 4 mM extracellular calcium ([Ca2+]o) and/or 1 μM nifedipine, 0.1 μM BAPTA-AM, 1 μM KN-93, 50 nM wortmannin for 10 days. The intracellular calcium ([Ca2+]i) levels were measured using Fluo 3-AM by flow cytometry. The adipogenic differentiation of pBMSCs was determined by Oil Red-O staining and triglyceride assay. The expression of marker genes involved in adipogenesis (peroxisome proliferator activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα)) and glucose uptake (glucose transporter 4 (GLUT4)), as well as the activation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) and PI3K/Akt-FoxO1/AS160 signaling pathways were determined by Western blotting. Glucose uptake and utilization were examined using 2-NBDG assay and glucose content assay, respectively. In vivo, C57BL/6J male mice were fed a HFD (containing 1.2% calcium) without or with 0.6% (w/w) calcium chloride in drinking water for 13 weeks. The adipogenesis, glucose homeostasis and the involvement of CaMKII and PI3K/Akt signaling pathway were also assessed. Results: In vitro, [Ca2+]o stimulated pBMSCs adipogenesis by increasing [Ca2+]i level and activating CaMKII and PI3K/Akt-FoxO1 pathways. In addition, [Ca2+]o promoted glucose uptake/utilization by enhancing AS160 phosphorylation, GLUT4 expression and translocation. However, the stimulating effects of [Ca2+]o on pBMSCs adipogenesis and glucose uptake/utilization were abolished by L-VGCC blocker Nifedipine, [Ca2+]i chelator BAPTA-AM, CaMKII inhibitor KN-93, or PI3K inhibitor Wortmannin. In vivo, calcium supplementation decreased body weight and fat content, increased adipocyte number, and improved glucose homeostasis, with elevated PPARγ and GLUT4 expression and PI3K/Akt activation in iWAT. Conclusion: calcium supplementation enhanced adipogenesis and glucose uptake in pBMSCs, which was coincident with the increased adipocyte number and improved glucose homeostasis in HFD-fed mice, and was associated with activation of CaMKII and PI3K/Akt-FoxO1/AS160 pathways. These data provided a broader understanding of the mechanisms underlying calcium-induced body weight/fat loss and glycemic control
Direct and indirect effects of climate on richness drive the latitudinal diversity gradient in forest trees
Data accessibility statement: Full census data are available upon reasonable request from the ForestGEO data portal, http://ctfs.si.edu/datarequest/ We thank Margie Mayfield, three anonymous reviewers and Jacob Weiner for constructive comments on the manuscript. This study was financially supported by the National Key R&D Program of China (2017YFC0506100), the National Natural Science Foundation of China (31622014 and 31570426), and the Fundamental Research Funds for the Central Universities (17lgzd24) to CC. XW was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB3103). DS was supported by the Czech Science Foundation (grant no. 16-26369S). Yves Rosseel provided us valuable suggestions on using the lavaan package conducting SEM analyses. Funding and citation information for each forest plot is available in the Supplementary Information Text 1.Peer reviewedPostprin
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