2,318 research outputs found
A CRY-BIC negative-feedback circuitry regulating blue light sensitivity of Arabidopsis.
Cryptochromes are blue light receptors that regulate various light responses in plants. Arabidopsis cryptochrome 1 (CRY1) and cryptochrome 2 (CRY2) mediate blue light inhibition of hypocotyl elongation and long-day (LD) promotion of floral initiation. It has been reported recently that two negative regulators of Arabidopsis cryptochromes, Blue light Inhibitors of Cryptochromes 1 and 2 (BIC1 and BIC2), inhibit cryptochrome function by blocking blue light-dependent cryptochrome dimerization. However, it remained unclear how cryptochromes regulate the BIC gene activity. Here we show that cryptochromes mediate light activation of transcription of the BIC genes, by suppressing the activity of CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), resulting in activation of the transcription activator ELONGATED HYPOCOTYL 5 (HY5) that is associated with chromatins of the BIC promoters. These results demonstrate a CRY-BIC negative-feedback circuitry that regulates the activity of each other. Surprisingly, phytochromes also mediate light activation of BIC transcription, suggesting a novel photoreceptor co-action mechanism to sustain blue light sensitivity of plants under the broad spectra of solar radiation in nature
The CDEX-1 1 kg Point-Contact Germanium Detector for Low Mass Dark Matter Searches
The CDEX Collaboration has been established for direct detection of light
dark matter particles, using ultra-low energy threshold p-type point-contact
germanium detectors, in China JinPing underground Laboratory (CJPL). The first
1 kg point-contact germanium detector with a sub-keV energy threshold has been
tested in a passive shielding system located in CJPL. The outputs from both the
point-contact p+ electrode and the outside n+ electrode make it possible to
scan the lower energy range of less than 1 keV and at the same time to detect
the higher energy range up to 3 MeV. The outputs from both p+ and n+ electrode
may also provide a more powerful method for signal discrimination for dark
matter experiment. Some key parameters, including energy resolution, dead time,
decay times of internal X-rays, and system stability, have been tested and
measured. The results show that the 1 kg point-contact germanium detector,
together with its shielding system and electronics, can run smoothly with good
performances. This detector system will be deployed for dark matter search
experiments.Comment: 6 pages, 8 figure
Microvesicles secreted by macrophages shuttle invasion-potentiating microRNAs into breast cancer cells
<p>Abstract</p> <p>Background</p> <p>Tumor-associated macrophages (TAMs) are alternatively activated cells induced by interleukin-4 (IL-4)-releasing CD4<sup>+ </sup>T cells. TAMs promote breast cancer invasion and metastasis; however, the mechanisms underlying these interactions between macrophages and tumor cells that lead to cancer metastasis remain elusive. Previous studies have found microRNAs (miRNAs) circulating in the peripheral blood and have identified microvesicles, or exosomes, as mediators of cell-cell communication. Therefore, one alternative mechanism for the promotion of breast cancer cell invasion by TAMs may be through macrophage-secreted exosomes, which would deliver invasion-potentiating miRNAs to breast cancer cells.</p> <p>Results</p> <p>We utilized a co-culture system with IL-4-activated macrophages and breast cancer cells to verify that miRNAs are transported from macrophages to breast cancer cells. The shuttling of fluorescently-labeled exogenous miRNAs from IL-4-activated macrophages to co-cultivated breast cancer cells without direct cell-cell contact was observed. miR-223, a miRNA specific for IL-4-activated macrophages, was detected within the exosomes released by macrophages and was significantly elevated in the co-cultivated SKBR3 and MDA-MB-231 cells. The invasiveness of the co-cultivated breast cancer cells decreased when the IL-4-activated macrophages were treated with a miR-223 antisense oligonucleotide (ASO) that would inhibit miR-223 expression. Furthermore, results from a functional assay revealed that miR-223 promoted the invasion of breast cancer cells via the Mef2c-β-catenin pathway.</p> <p>Conclusions</p> <p>We conclude that macrophages regulate the invasiveness of breast cancer cells through exosome-mediated delivery of oncogenic miRNAs. Our data provide insight into the mechanisms underlying the metastasis-promoting interactions between macrophages and breast cancer cells.</p
Texture Classification Network Integrating Adaptive Wavelet Transform
Graves' disease is a common condition that is diagnosed clinically by
determining the smoothness of the thyroid texture and its morphology in
ultrasound images. Currently, the most widely used approach for the automated
diagnosis of Graves' disease utilizes Convolutional Neural Networks (CNNs) for
both feature extraction and classification. However, these methods demonstrate
limited efficacy in capturing texture features. Given the high capacity of
wavelets in describing texture features, this research integrates learnable
wavelet modules utilizing the Lifting Scheme into CNNs and incorporates a
parallel wavelet branch into the ResNet18 model to enhance texture feature
extraction. Our model can analyze texture features in spatial and frequency
domains simultaneously, leading to optimized classification accuracy. We
conducted experiments on collected ultrasound datasets and publicly available
natural image texture datasets, our proposed network achieved 97.27% accuracy
and 95.60% recall on ultrasound datasets, 60.765% accuracy on natural image
texture datasets, surpassing the accuracy of ResNet and conrming the
effectiveness of our approach
Reconfigurable Meta-Radiator Based on Flexible Mechanically Controlled Current Distribution in Three-dimensional Space
In this paper, we provide an experimental proof-of-concept of this dynamic 3D
current manipulation through a 3D-printed reconfigurable meta-radiator with
periodically slotted current elements. By utilizing the working frequency and
the mechanical configuration comprehensively, the radiation pattern can be
switched among 12 states. Inspired by maximum likelihood method in digital
communications, a robustness-analysis method is proposed to evaluate the
potential error ratio between ideal cases and practice. Our work provides a
previously unidentified model for next-generation information distribution and
terahertz-infrared wireless communications
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