Optogenetics is a powerful technique that allows target-specific spatiotemporal manipulation of neuronal activity for dissection of neural circuits and therapeutic interventions. Recent advances in ...wireless optogenetics technologies have enabled investigation of brain circuits in more natural conditions by releasing animals from tethered optical fibers. However, current wireless implants, which are largely based on battery-powered or battery-free designs, still limit the full potential of in vivo optogenetics in freely moving animals by requiring intermittent battery replacement or a special, bulky wireless power transfer system for continuous device operation, respectively. To address these limitations, here we present a wirelessly rechargeable, fully implantable, soft optoelectronic system that can be remotely and selectively controlled using a smartphone. Combining advantageous features of both battery-powered and battery-free designs, this device system enables seamless full implantation into animals, reliable ubiquitous operation, and intervention-free wireless charging, all of which are desired for chronic in vivo optogenetics. Successful demonstration of the unique capabilities of this device in freely behaving rats forecasts its broad and practical utilities in various neuroscience research and clinical applications.
In this study, a quasi-autonomous vision-based method is newly proposed for detecting loosened bolts in critical connections. The main idea of the approach is to estimate the rotational angles of ...bolts from the connection images by integrating deep learning technology with image processing techniques. Firstly, a regional convolutional neural network (RCNN)-based deep learning algorithm is developed to automatically detect and crop plausible bolts in the connection image. Also, the Hough line transform (HLT)-based image processing algorithm is designed to automatically estimate the bolt angles from the cropped bolt images. Secondly, the proposed vision-based approach is validated for bolt-loosening detection in a lab-scale girder connection using images captured by a smartphone camera. The accuracy of the RCNN-based bolt detector and the HLT-based bolt angle estimator are examined under different levels of perspective distortion and shooting distance. Finally, the practicality of the proposed vision-based method is verified on a real-scale girder bridge connection containing numerous bolts. The images of the connection are captured by an unmanned aerial vehicle and transferred to a computer where a quasi-autonomous bolt-loosening detection process is performed via the proposed algorithm. The experimental results demonstrate potentials of the proposed approach for quasi real-time bolt-loosening monitoring of large bolted connections. The results show that the perspective angle should not go beyond 40 degrees to ensure the accuracy of the detection results.
•A vision-based bolt-loosening detection method is newly proposed.•The method integrates deep learning with Hough transform to estimate bolt rotations.•The method can identify bolts in an image captured under an arbitrary perspective.•The method is robust in detecting small bolt-loosening severities.•The method is suitable for monitoring realistic and large bolted connections.
The outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in China and rapidly spread worldwide. To prevent SARS-CoV-2 ...dissemination, understanding the in vivo characteristics of SARS-CoV-2 is a high priority. We report a ferret model of SARS-CoV-2 infection and transmission that recapitulates aspects of human disease. SARS-CoV-2-infected ferrets exhibit elevated body temperatures and virus replication. Although fatalities were not observed, SARS-CoV-2-infected ferrets shed virus in nasal washes, saliva, urine, and feces up to 8 days post-infection. At 2 days post-contact, SARS-CoV-2 was detected in all naive direct contact ferrets. Furthermore, a few naive indirect contact ferrets were positive for viral RNA, suggesting airborne transmission. Viral antigens were detected in nasal turbinate, trachea, lungs, and intestine with acute bronchiolitis present in infected lungs. Thus, ferrets represent an infection and transmission animal model of COVID-19 that may facilitate development of SARS-CoV-2 therapeutics and vaccines.
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•SARS-CoV-2-infected ferrets exhibit elevated body temperature and virus replication•SARS-CoV-2 is shed in nasal washes, saliva, urine and feces•SARS-CoV-2 is effectively transmitted to naive ferrets by direct contact•SARS-CoV-2 infection leads acute bronchiolitis in infected ferrets
The outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly spreads, leading to a pandemic infection. Kim et al. show that ferrets are highly susceptible to SARS-CoV-2 infection and effectively transmit the virus by direct or indirect contact, recapitulating human infection and transmission.
Summary
miR156 and its target SQUAMOSA PROMOTER BINDING PROTEIN‐LIKE (SPL) genes constitute an endogenous flowering pathway in Arabidopsis. The SPL genes are regulated post‐transcriptionally by ...miR156, and incorporate endogenous aging signals into floral gene networks. Intriguingly, the SPL genes are also regulated transcriptionally by FLOWERING LOCUS T (FT)‐mediated photoperiod signals. However, it is unknown how photoperiod regulates the SPL genes. Here, we show that SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) and FT regulate the SPL3, SPL4 and SPL5 genes by directly binding to the gene promoters in response to photoperiod signals. Notably, the SOC1 regulation of the SPL genes, termed the SOC1‐SPL module, also mediates gibberellic acid (GA) signals to promote flowering under non‐inductive short days (SDs). Under SDs, the inductive effects of GA on the SPL genes disappeared in the soc1‐2 mutant, and the flowering of SPL3‐overexpressing transgenic plants (35S:SPL3) was less sensitive to GA. In addition, the 35S:SPL3 × soc1‐2 plants flowered much earlier than the soc1‐2 mutant, supporting SOC1 regulation of the SPL genes. Our observations indicate that the SOC1‐SPL module serves as a molecular link that integrates photoperiod and GA signals to promote flowering in Arabidopsis.
Localization of messenger ribonucleoproteins (mRNPs) plays an essential role in the regulation of gene expression for long-term memory formation and neuronal development. Knowledge concerning the ...nature of neuronal mRNP transport is thus crucial for understanding how mRNPs are delivered to their target synapses. Here, we report experimental and theoretical evidence that the active transport dynamics of neuronal mRNPs, which is distinct from the previously reported motor-driven transport, follows an aging Lévy walk. Such nonergodic, transient superdiffusion occurs because of two competing dynamic phases: the motor-involved ballistic run and static localization of mRNPs. Our proposed Lévy walk model reproduces the experimentally extracted key dynamic characteristics of mRNPs with quantitative accuracy. Moreover, the aging status of mRNP particles in an experiment is inferred from the model. This study provides a predictive theoretical model for neuronal mRNP transport and offers insight into the active target search mechanism of mRNP particles in vivo.
•Biogenic amine content of fermented soybeans were compared to recommended limits.•Most fermented soybean foods contained potentially hazardous biogenic amine content.•Regulation of biogenic amines ...in fermented soybean foods are currently insufficient.•Control of biogenic amines is necessary to produce safe fermented soybean foods.
Biogenic amines are harmful substances generated during the fermentation process. Regulations on biogenic amine content in fermented foods are currently insufficient in comparison to the popularity of fermented food consumption in Asian countries. The current review evaluated the biogenic amine content of fermented soybean-based Asian foods to determine whether the food products are safe for consumption. Though the reported ranges of biogenic amine content in fermented soybean foods varied widely, most products contained biogenic amine concentrations at potentially hazardous levels. To ensure the safety of fermented soybean food products, further efforts are required in the improvement of the food manufacturing process, as well as the establishment of regulations on managing biogenic amine content.
X-ray coronary angiography is a primary imaging technique for diagnosing coronary diseases. Although quantitative coronary angiography (QCA) provides morphological information of coronary arteries ...with objective quantitative measures, considerable training is required to identify the target vessels and understand the tree structure of coronary arteries. Despite the use of computer-aided tools, such as the edge-detection method, manual correction is necessary for accurate segmentation of coronary vessels. In the present study, we proposed a robust method for major vessel segmentation using deep learning models with fully convolutional networks. When angiographic images of 3302 diseased major vessels from 2042 patients were tested, deep learning networks accurately identified and segmented the major vessels in X-ray coronary angiography. The average F1 score reached 0.917, and 93.7% of the images exhibited a high F1 score > 0.8. The most narrowed region at the stenosis was distinctly captured with high connectivity. Robust predictability was validated for the external dataset with different image characteristics. For major vessel segmentation, our approach demonstrated that prediction could be completed in real time with minimal image preprocessing. By applying deep learning segmentation, QCA analysis could be further automated, thereby facilitating the use of QCA-based diagnostic methods.
Stomata are epidermal openings that facilitate plant-atmosphere gas exchange during photosynthesis, respiration, and water evaporation. Stomatal differentiation and patterning are spatially and ...temporally regulated by the master regulators SPEECHLESS (SPCH), MUTE, and FAMA, which constitute a central gene regulatory network along with Inducer of CBF Expression (ICE) transcription factors for this developmental process. Stomatal development is also profoundly influenced by environmental conditions, such as light, temperature, and humidity. Light induces stomatal development, and various photoreceptors modulate this response. However, it is unknown how light is functionally linked with the master regulatory network. Here, we demonstrate that, under dark conditions, the E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) degrades ICE proteins through ubiquitination pathways in leaf abaxial epidermal cells in Arabidopsis thaliana. Accordingly, the ICE proteins accumulate in the nuclei of leaf abaxial epidermal cells in COP1-defective mutants, which constitutively produce stomata. Notably, light in the blue, red, and far-red wavelength ranges suppresses the COP1-mediated degradation of the ICE proteins to induce stomatal development. These observations indicate that light is directly linked with the ICE-directed signaling module, via the COP1-mediated protein surveillance system, in the modulation of stomatal development.
Localization of messenger RNA (mRNA) in dendrites is crucial for regulating gene expression during long-term memory formation. mRNA binds to RNA-binding proteins (RBPs) to form messenger ...ribonucleoprotein (mRNP) complexes that are transported by motor proteins along microtubules to their target synapses. However, the dynamics by which mRNPs find their target locations in the dendrite have not been well understood. Here, we investigated the motion of endogenous β-actin and Arc mRNPs in dissociated mouse hippocampal neurons using the MS2 and PP7 stem-loop systems, respectively. By evaluating the statistical properties of mRNP movement, we found that the aging Lévy walk model effectively describes both β-actin and Arc mRNP transport in proximal dendrites. A critical difference between β-actin and Arc mRNPs was the aging time, the time lag between transport initiation and measurement initiation. The longer mean aging time of β-actin mRNP (~100 s) compared with that of Arc mRNP (~30 s) reflects the longer half-life of constitutively expressed β-actin mRNP. Furthermore, our model also permitted us to estimate the ratio of newly generated and pre-existing β-actin mRNPs in the dendrites. This study offers a robust theoretical framework for mRNP transport, which provides insight into how mRNPs locate their targets in neurons.
Hypoxia, a condition in which the tissue is deprived of adequate oxygen supply, is a salient feature of various intractable diseases, including rheumatoid arthritis, ischemic stroke, and solid ...tumors. In particular, hypoxic regions in tumors are often associated with invasiveness, metastasis, and resistance to radiotherapy and chemotherapy. Given its unique role in tumor progression, hypoxia has been considered to be a primary target for the diagnosis and treatment of cancer. Owing to their sizes and tailorable physicochemical characteristics, nanocarriers are an emerging class of materials that are increasingly utilized in biomedical applications. Particularly, stimuli-responsive nanocarriers, which release their payloads specifically at the tumor-microenvironment, are materials of interest. Owing to the aberrant vascular properties of tumors, the transportation of anticancer drugs to hypoxic regions is challenging because they are distant from blood vessels. In addition, hypoxia upregulates various genes involved in drug resistance such as P-glycoprotein. To surmount the issues associated with hypoxia, nanocarriers that can release imaging agents or anticancer drugs in hypoxic regions must be developed. This review focuses on recently developed hypoxia-responsive conjugates or nanocarriers and their potential applications in cancer imaging and therapy. Low oxygen levels bring forth conformational changes in hypoxia-responsive nanocarriers through the cleavage or reduction of hypoxia-responsive functional groups. A greater understanding of these changes will help to design more efficient nanocarriers to address the challenges encountered with hypoxia in conventional chemotherapy.
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