457 research outputs found
Poly[[μ-aqua-bis(μ-4,4′-bipyridine-κ2 N:N′)bis(μ-3-hydroxyadamantane-1-carboxylato-κ2 O:O′)bis(3-hydroxyadamantane-1-carboxylato-κO)dicobalt(II)] heptahydrate]
The title coordination compound, {[Co(C11H15O3)4(C10H8N2)2(H2O)]·7H2O}n, consists of a pair of CoII atoms, four 3-hydroxyadamantane-1-carboxylate anions (L), one water molecule, two bridging 4,4′-bipyridine (4,4′-bpy) ligands and seven uncoordinated water molecules. Both of the CoII ions are coordinated in a distorted octahedral geometry. Four L ligands bind to each pair of CoII atoms in a plane, two of which bridge the two CoII atoms as bidentate groups while the other two coordinate to a single CoII atom in a monodentate mode. Two half-molecules of 4,4′-bipyridine coordinate the CoII atoms from the upside and underside. The packing features extensice O—H⋯O hydrogen bonding
The universal "heartbeat" oscillations in black hole systems accross the mass-scale
The hyperluminous X-ray source (HLX-1, the peak X-ray luminosity ) near the spiral galaxy ESO 243-49 is possibly the best
candidate for intermediate mass black hole (IMBH), which underwent recurrent
outbursts with a period of days. The physical reason for this
quasi-periodic variability is still unclear. We explore the possibility of
radiation-pressure instability in accretion disk by modeling the light curve of
HLX-1, and find that it can roughly reproduce the duration, period and
amplitude of the recurrent outbursts HLX-1 with an IMBH of ~10^5Msun. Our
result provides a possible mechanism to explain the recurrent outbursts in
HLX-1. We further find a universal correlation between the outburst duration
and the bolometric luminosity for the BH sources with a very broad mass range
(e.g., X-ray binaries, XRBs, HLX-1 and active galactic nuclei, AGNs), which is
roughly consistent with the prediction of radiation-pressure instability of the
accretion disk. These results imply that "heartbeat" oscillations triggered by
radiation-pressure instability may appears in different-scale BH systems.Comment: ApJ in press; 15 pages, 5 Figure
NG2 cells response to axonal alteration in the spinal cord white matter in mice with genetic disruption of neurofilament light subunit expression
<p>Abstract</p> <p>Background</p> <p>Chondroitin sulphate proteoglycan (NG2) expressing cells, morphologically characterized by multi-branched processes and small cell bodies, are the 4<sup>th </sup>commonest cell population of non-neuronal cell type in the central nervous system (CNS). They can interact with nodes of Ranvier, receive synaptic input, generate action potential and respond to some pathological stimuli, but the function of the cells is still unclear. We assumed the NG2 cells may play an active role in neuropathogenesis and aimed to determine if NG2 cells could sense and response to the alterations in the axonal contents caused by disruption of neurofilament light subunit (NFL) expression.</p> <p>Results</p> <p>In the early neuropathological development stage, our study showed that the diameter of axons of upper motor neurons of NFL-/- mice decreased significantly while the thickness of their myelin sheath increased remarkably. Although there was an obvious morphological distortion in axons with occasionally partial demyelination, no obvious changes in expression of myelin proteins was detected. Parallel to these changes in the axons and their myelination, the processes of NG2 cells were disconnected from the nodes of Ranvier and extended further, suggesting that these cells in the spinal cord white matter could sense the alteration in axonal contents caused by disruption of NFL expression before astrocytic and microglial activation.</p> <p>Conclusion</p> <p>The structural configuration determined by the NFL gene may be important for maintenance of normal morphology of myelinated axons. The NG2 cells might serve as an early sensor for the delivery of information from impaired neurons to the local environment.</p
The Online Data Quality Monitoring System at BESIII
The online Data Quality Monitoring (DQM) plays an important role in the data
taking process of HEP experiments. BESIII DQM samples data from online data
flow, reconstructs them with offline reconstruction software, and automatically
analyzes the reconstructed data with user-defined algorithms. The DQM software
is a scalable distributed system. The monitored results are gathered and
displayed in various formats, which provides the shifter with current run
information that can be used to find problems early. This paper gives an
overview of DQM system at BESIII.Comment: Already submit to Chinese Physics
ManagerTower: Aggregating the Insights of Uni-Modal Experts for Vision-Language Representation Learning
Two-Tower Vision-Language (VL) models have shown promising improvements on
various downstream VL tasks. Although the most advanced work improves
performance by building bridges between encoders, it suffers from ineffective
layer-by-layer utilization of uni-modal representations and cannot flexibly
exploit different levels of uni-modal semantic knowledge. In this work, we
propose ManagerTower, a novel VL model architecture that gathers and combines
the insights of pre-trained uni-modal experts at different levels. The managers
introduced in each cross-modal layer can adaptively aggregate uni-modal
semantic knowledge to facilitate more comprehensive cross-modal alignment and
fusion. ManagerTower outperforms previous strong baselines both with and
without Vision-Language Pre-training (VLP). With only 4M VLP data, ManagerTower
achieves superior performances on various downstream VL tasks, especially
79.15% accuracy on VQAv2 Test-Std, 86.56% IR@1 and 95.64% TR@1 on Flickr30K.
Code and checkpoints are available at https://github.com/LooperXX/ManagerTower.Comment: Accepted by ACL 2023 Main Conference, Ora
Rapid identification of micro and nanoplastics by line scan Raman micro-spectroscopy
Microplastic pollution has become an environmental problem that cannot be ignored in our society. Raman spectroscopy technology has been widely used in the field of microplastics detection due to its non-contact, non-destructive chemical specificity. Traditional point confocal Raman micro-spectroscopy technology uses single-point detection, resulting in long measurement times to scan the large areas of interest of typical samples. In this paper, we present a line scan confocal Raman micro-spectroscopy tool for fast detection and identification of microplastic particles. We show size and composition identification of particles and imaging over large areas. Compared with point confocal Raman imaging, the line scan confocal Raman technology increases the imaging speed by 1–2 orders of magnitude
A new species of the genus Achalinus (Squamata, Xenodermatidae) from southwest Hunan Province, China
A new species of xenodermid snake, Achalinus nanshanensis H. Li, L.-Q. Zhu, Z.-Q. Zhang &amp; X.-Y. Mo, sp. nov., is described based on three specimens collected from Nanshan National Park and Tongdao County of southwest Hunan Province. This new species is genetically distinct amongst its congeners with the mitochondrial COI uncorrected p-distance ranging from 4.4% (in A. yangdatongi) to 17.7% (in A. meiguensis). In addition, this new species can be distinguished from its congeners by a combination of the following morphological characters: (1) dorsal scales with 23 or 25 rows throughout and strongly keeled; (2) tail relatively longer so that TaL/ToL = 0.215–0.248; (3) length of suture between internasals significantly longer than that between prefrontals, LSBI/LSBP = 1.66–1.84; (4) single loreal scale present; (5) SPL 6 in number, with the fourth and fifth contacting eye; (6) IFL 6 in number, with the first three touching the first pair of chin shields; (7) TMP is 2-2-4/2-2(3)-4, with the anterior pair elongated and in contact with the eye; (8) ventrals 2 + 147–158; (9) subcaudals 64–77, unpaired; (10) dorsal body brownish black, with a bright yellow neck collar extending to the head and abdomen in the occipital region. The recognition of the new species increases the number of described Achalinus species to 28, of which 21 are found in China
Online quality control of panaxatriol saponins percolation extraction using near-infrared technology
Purpose: To establish a new prediction model for online quality control of the percolation extraction of panaxatriol saponins (PTS), viz, ginsenoside Rg1, ginsenoside Re and notoginsenoside R1, from notoginseng by near-infrared (NIR) technology coupled with partial least squares (PLS) analysis.Methods: Ten batches of PTS (420 samples) were collected and the constituents were determined using HPLC. The NIR spectroscopy of samples was determined using a Fourier-Transform nearinfrared spectrometer with an optical fiber transmission PbS detector. Eight sample batches were the calibration set, and two batches were the forecast set. Calibration models were established based on min-max normalization (MMN).Results: The root mean square errors of cross-validation (RMSECV) of Rg1, Re, and R1 were 0.798, 0.095, and 0.259 mg/mL, respectively. The root mean square errors of prediction (RMSEP) were 1.110, 0.496, and 0.390 mg/mL, respectively. The correlation coefficients (R2) of cross-validation were 0.9682, 0.9681, and 0.9626, respectively, while the correlation coefficients (R2) of prediction were 0.9831, 0.9198, and 0.9661, respectively.Conclusion: The results indicate that NIR is a quick and effective tool for online quality control of PTS (ginsenoside Rg1, ginsenoside Re, and notoginsenoside R1) in the percolation extraction process.Keywords: Online monitoring, Near infrared technology, Panaxatriol saponins, Partial least square
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KARR-seq reveals cellular higher-order RNA structures and RNA–RNA interactions
RNA fate and function are affected by their structures and interactomes. However, how RNA and RNA-binding proteins (RBPs) assemble into higher-order structures and how RNA molecules may interact with each other to facilitate functions remain largely unknown. Here we present KARR-seq, which uses N3-kethoxal labeling and multifunctional chemical crosslinkers to covalently trap and determine RNA–RNA interactions and higher-order RNA structures inside cells, independent of local protein binding to RNA. KARR-seq depicts higher-order RNA structure and detects widespread intermolecular RNA–RNA interactions with high sensitivity and accuracy. Using KARR-seq, we show that translation represses mRNA compaction under native and stress conditions. We determined the higher-order RNA structures of respiratory syncytial virus (RSV) and vesicular stomatitis virus (VSV) and identified RNA–RNA interactions between the viruses and the host RNAs that potentially regulate viral replication
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