24 research outputs found
Nonreciprocal Metasurface with Space-Time Phase Modulation
Creating materials with time-variant properties is critical for breaking
reciprocity that imposes fundamental limitations to wave propagation. However,
it is challenging to realize efficient and ultrafast temporal modulation in a
photonic system. Here, leveraging both spatial and temporal phase manipulation
offered by an ultrathin nonlinear metasurface, we experimentally demonstrated
nonreciprocal light reflection at wavelengths around 860 nm. The metasurface,
with traveling-wave modulation upon nonlinear Kerr building blocks, creates
spatial phase gradient and multi-terahertz temporal phase wobbling, which leads
to unidirectional photonic transitions in both momentum and energy spaces. We
observed completely asymmetric reflections in forward and backward light
propagations within a sub-wavelength interaction length of 150 nm. Our approach
pointed out a potential means for creating miniaturized and integratable
nonreciprocal optical components.Comment: 25 pages, 5 figure
Molding Free-Space Light with Guided-Wave-Driven Metasurfaces
Metasurfaces with unparalleled controllability of light have shown great
potential to revolutionize conventional optics. However, they mainly work with
free-space light input, which makes it difficult for full on-chip integration.
On the other hand, integrated photonics enables densely packed devices but has
limited free-space light controllability. Here, we show that judiciously
designed guided-wave-driven metasurfaces can mold guided waves into arbitrary
free-space modes to achieve complex free-space functions, such as beam steering
and focusing, with ultrasmall footprints and potentially no diffraction loss.
Based on the same concept together with broken inversion symmetry induced by
metasurfaces, we also realized direct orbital angular momentum (OAM) lasing
from a micro-ring resonator. Our study works towards complete control of light
across integrated photonics and free-space platforms, and paves new exciting
ways for creating multifunctional photonic integrated devices with agile access
to free space which could enable a plethora of applications in communications,
remote sensing, displays, and etc.Comment: 37 pages, 5 figure
SC1 Promotes MiR124-3p Expression to Maintain the Self-Renewal of Mouse Embryonic Stem Cells by Inhibiting the MEK/ERK Pathway
High Follicle-Stimulating Hormone Level Associated With Risk of Rheumatoid Arthritis and Disease Activity
BackgroundThe prevalence of rheumatoid arthritis (RA) has significant gender and age difference. The peak age of RA is consistent with the age of menopause, which is accompanied by a sharp increase in serum follicle-stimulating hormone (FSH) level. This study aims to identify the FSH levels in female RA patients and the relationship with diseases activity.MethodsIn total, 79 female RA patients and 50 age-matched controls were included in our study. Serum sex hormones levels were measured using chemiluminescence. RA patients were grouped by FSH quartile. Disease activity and inflammatory marks were analyzed among groups.ResultsLower sex hormones and higher gonadotropin were found in RA patients. Serum FSH level was significantly higher in RA patients than in the age-match controls (57.58 ± 15.94 vs. 43.11 ± 19.46, p=0.025). Even after adjusting for age (OR: 1.071; 95%CI: 1.006-1.139; p = 0.031), luteinizing hormone (LH), estradiol (E), and testosterone (T) OR: 1.066; 95%CI: 1.003-1.133; p = 0.039), the OR were still more than one. RA patients in the higher quartiles had higher ESR, DAS28-ESR and DAS28-CRP (p<0.05) than the lowest quartile. Besides, menopause age was significantly related with onset age in post-menopause RA patients (r = 0.432, p =0.008).ConclusionHigh FSH appears to be a risk factor for RA and is positively associated with their disease activity. Early menopause might be an essential factor of RA
Corrigendum: High follicle-stimulating hormone level associated with risk of rheumatoid arthritis and disease activity
Hepatotoxic Components Effect of <i>Chebulae Fructus</i> and Associated Molecular Mechanism by Integrated Transcriptome and Molecular Docking
Chebulae Fructus (CF) is a natural medicinal plant widely used for its various pharmacological properties. Natural products used to cure several diseases have been considered safe thanks to their little or no side effects. However, in recent years, a hepatotoxic effect has been found due to the abuse of herbal medicine. CF has been reported to have hepatotoxicity, but the mechanism is unclear. In this experiment, the toxic aspect and mechanism of CF action were evaluated by transcriptome analysis. Components of toxic CF fractions were identified by LC-MS, and hepatotoxic toxic components in toxic CF fractions were predicted by molecular docking. The results showed that the ethyl acetate part of CF was the main toxic fraction, and transcriptome analysis found that the toxic mechanism was highly related to lipid metabolism-related pathways, and CFEA could inhibit the PPAR signaling pathway. Molecular docking results showed that 3′-O-methyl-4-O-(n″-O-galloyl-β-d-xylopyranosyl) ellagic acid (n = 2, 3 or 4) and 4-O-(3″,4″-O-digalloyl-α-l-rhamnosyl) ellagic acid have better docking energies with PPARα protein and FABP protein than other components. In summary, 3′-O-methyl-4-O-(n″-O-galloyl-β-d-xylopyranosyl) ellagic acid (n = 2, 3 or 4) and 4-O-(3″,4″-O-digalloyl-α-l-rhamnosyl) ellagic acid were the main toxic components, which may play a toxic role by inhibiting the PPAR signaling pathway and affect lipid metabolism
SC1 Promotes MiR124-3p Expression to Maintain the Self-Renewal of Mouse Embryonic Stem Cells by Inhibiting the MEK/ERK Pathway
Background/Aims: Self-renewal is one of the most important features of embryonic stem (ES) cells. SC1 is a small molecule modulator that effectively maintains the self-renewal of mouse ES cells in the absence of leukemia inhibitory factor (LIF), serum and feeder cells. However, the mechanism by which SC1 maintains the undifferentiated state of mouse ES cells remains unclear. Methods: In this study, microarray and small RNA deep-sequencing experiments were performed on mouse ES cells treated with or without SC1 to identify the key genes and microRNAs that contributed to self-renewal. Results: SC1 regulates the expressions of pluripotency and differentiation factors, and antagonizes the retinoic acid (RA)-induced differentiation in the presence or absence of LIF. SC1 inhibits the MEK/ERK pathway through Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and pathway reporting experiments. Small RNA deep-sequencing revealed that SC1 significantly modulates the expression of multiple microRNAs with crucial functions in ES cells. The expression of miR124-3p is upregulated in SC1-treated ES cells, which significantly inhibits the MEK/ERK pathway by targeting Grb2, Sos2 and Egr1. Conclusion: SC1 enhances the self-renewal capacity of mouse ES cells by modulating the expression of key regulatory genes and pluripotency-associated microRNAs. SC1 significantly upregulates miR124-3p expression to further inhibit the MEK/ ERK pathway by targeting Grb2, Sos2 and Egr1