862 research outputs found
trans-TetraÂkis(1-allyl-1H-imidazole-κN 3)bisÂ(thioÂcyanato-κN)nickel(II)
The structure of the title compound, [Ni(NCS)2(C6H8N2)4], consists of isolated molÂecules of [Ni(NCS)2(Aim)4] (Aim = 1-allylÂimidazole), which contain a distorted octaÂhedral NiN6 chromophore. The NCS− anions are trans and four N atoms from the 1-allylÂimidazole ligands define the equatorial plane. The mean Mn—N(Aim) and Mn—N(NCS) distances are 2.105 (2) and 2.098 (2) Å, respectively. Weak C—H⋯N interÂactions contribute to the crystal packing stability
Local electrochemical impedance spectroscopy: A review and some recent developments
Local electrochemical impedance spectroscopy (LEIS), which provides a powerful tool for exploration of electrode heterogeneity, has its roots in the development of electrochemical techniques employing scanning of microelectrodes. The historical development of local impedance spectroscopy measurements is reviewed, and guidelines are presented for implementation of LEIS. The factors which control the limiting spatial resolution of the technique are identified. The mathematical foundation for the technique is reviewed, including definitions of interfacial and local Ohmic impedances on both local and global scales. Experimental results for the reduction of ferricyanide show the correspondence between local and global impedances. Simulations for a single Faradaic reaction on a disk electrode embedded in an insulator are used to show that the Ohmic contribution, traditionally considered to be a real value, can have complex character in certain frequency ranges
COCA: Classifier-Oriented Calibration for Source-Free Universal Domain Adaptation via Textual Prototype
Universal Domain Adaptation (UniDA) aims to distinguish common and private
classes between the source and target domains where domain shift exists.
Recently, due to more stringent data restrictions, researchers have introduced
Source-Free UniDA (SF-UniDA) in more realistic scenarios. SF-UniDA methods
eliminate the need for direct access to source samples when performing
adaptation to the target domain. However, existing SF-UniDA methods still
require an extensive quantity of labeled source samples to train a source
model, resulting in significant labeling costs. To tackle this issue, we
present a novel Classifier-Oriented Calibration (COCA) method. This method,
which leverages textual prototypes, is formulated for the source model based on
few-shot learning. Specifically, we propose studying few-shot learning, usually
explored for closed-set scenarios, to identify common and domain-private
classes despite a significant domain shift between source and target domains.
Essentially, we present a novel paradigm based on the vision-language model to
learn SF-UniDA and hugely reduce the labeling costs on the source domain.
Experimental results demonstrate that our approach outperforms state-of-the-art
UniDA and SF-UniDA models
Dual-Octave Convolution for Accelerated Parallel MR Image Reconstruction
Magnetic resonance (MR) image acquisition is an inherently prolonged process,
whose acceleration by obtaining multiple undersampled images simultaneously
through parallel imaging has always been the subject of research. In this
paper, we propose the Dual-Octave Convolution (Dual-OctConv), which is capable
of learning multi-scale spatial-frequency features from both real and imaginary
components, for fast parallel MR image reconstruction. By reformulating the
complex operations using octave convolutions, our model shows a strong ability
to capture richer representations of MR images, while at the same time greatly
reducing the spatial redundancy. More specifically, the input feature maps and
convolutional kernels are first split into two components (i.e., real and
imaginary), which are then divided into four groups according to their spatial
frequencies. Then, our Dual-OctConv conducts intra-group information updating
and inter-group information exchange to aggregate the contextual information
across different groups. Our framework provides two appealing benefits: (i) it
encourages interactions between real and imaginary components at various
spatial frequencies to achieve richer representational capacity, and (ii) it
enlarges the receptive field by learning multiple spatial-frequency features of
both the real and imaginary components. We evaluate the performance of the
proposed model on the acceleration of multi-coil MR image reconstruction.
Extensive experiments are conducted on an {in vivo} knee dataset under
different undersampling patterns and acceleration factors. The experimental
results demonstrate the superiority of our model in accelerated parallel MR
image reconstruction. Our code is available at:
github.com/chunmeifeng/Dual-OctConv.Comment: Proceedings of the 35th AAAI Conference on Artificial Intelligence
(AAAI) 202
N′2,N′5-Bis[(E)-2-hyÂdroxyÂbenzylÂidene]-3,4-dimethylÂthioÂphene-2,5-dicarbohydrazide
In the title molÂecule, C22H20N4O4S, both C=N bonds are in an E conformation. The benzene rings form dihedral angles of 12.10 (13) and 25.17 (12)° with the thioÂphene ring. The dihedral angle between the two benzene rings is 17.59 (14)°. There are two intraÂmolecular O—H⋯N hydrogen bonds. In the crystal, N—H⋯O hydrogen bonds connect molÂecules into chains along [010]
Recombinant VP1, an Akt Inhibitor, Suppresses Progression of Hepatocellular Carcinoma by Inducing Apoptosis and Modulation of CCL2 Production
BACKGROUND: The application of viral elements in tumor therapy is one facet of cancer research. Recombinant capsid protein VP1 (rVP1) of foot-and-mouth disease virus has previously been demonstrated to induce apoptosis in cancer cell lines. Here, we aim to further investigate its apoptotic mechanism and possible anti-metastatic effect in murine models of hepatocellular carcinoma (HCC), one of the most common human cancers worldwide. METHODOLOGY/PRINCIPAL FINDINGS: Treatment with rVP1 inhibited cell proliferation in two murine HCC cell lines, BNL and Hepa1-6, with IC₅₀ values in the range of 0.1-0.2 µM. rVP1 also induced apoptosis in these cells, which was mediated by Akt deactivation and dissociation of Ku70-Bax, and resulted in conformational changes and mitochondrial translocation of Bax, leading to the activation of caspases-9, -3 and -7. Treatment with 0.025 µM rVP1, which did not affect the viability of normal hepatocytes, suppressed cell migration and invasion via attenuating CCL2 production. The production of CCL2 was modulated by Akt-dependent NF-κB activation that was decreased after rVP1 treatment. The in vivo antitumor effects of rVP1 were assessed in both subcutaneous and orthotopic mouse models of HCC in immune-competent BALB/c mice. Intratumoral delivery of rVP1 inhibited subcutaneous tumor growth as a result of increased apoptosis. Intravenous administration of rVP1 in an orthotopic HCC model suppressed tumor growth, inhibited intra-hepatic metastasis, and prolonged survival. Furthermore, a decrease in the serum level of CCL2 was observed in rVP1-treated mice. CONCLUSIONS/SIGNIFICANCE: The data presented herein suggest that, via inhibiting Akt phosphorylation, rVP1 suppresses the growth, migration, and invasion of murine HCC cells by inducing apoptosis and attenuating CCL2 production both in vitro and in vivo. Recombinant protein VP1 thus has the potential to be developed as a new therapeutic agent for HCC
Dimension Increase via Hierarchical Hydrogen Bonding from Simple Pincer-like Mononuclear complexes
A tetradentate symmetric ligand bearing both coordination and hydrogen bonding sites, N1,N3-bis(1-(1H-benzimidazol-2-yl)-ethylidene)propane-1,3-diamine (H2bbepd) was utilized to synthesize a series of transition metal complexes, namely [Co(H2bbepd)(H2O)2]·2ClO4
(1), [Cu(H2bbepd)(OTs-)]·OTs- (2),[Cu(bbepd)(CH3OH)] (3), [Cd(H2bbepd)(NO3)2]·CH3OH (4), [Cd(H2bbepd)(CH3OH)Cl]·Cl (5), and
[Cd(bbepd)(CH3OH)2] (6). These complexes show similar discrete pincer-like coordination units, possessing different arrangements of hydrogen bonding donor and acceptor sites. With or without the aid of uncoordinated anions and solvent molecules, such mononuclear
units have been effectively involved in the construction of hierarchical hydrogen bonding assemblies (successively via level I and level II), leading to discrete binuclear ring (complex 2), one-dimensional chain or ribbon (complexes 3, 4 and 6) and
two-dimensional layer (complexes 1 and 5) aggregates
Prosecution records reveal pangolin trading networks in China, 2014–2019
In a precautionary response to the current coronavirus (COVID-19) pandemic, China’s Ministries permanently banned eating and trading in terrestrial wild (non-livestock) animals on 24 February 2020, and extensively updated the list of Fauna under Special State Protection (LFSSP) in 2020 and 2021, in which pangolins (Manidae spp.) were upgraded to the highest protection level. Examining 509 pangolin prosecution records from China Judgements online prior to these changes (01/01/14–31/12/19), we identified that Guangdong, Guangxi and Yunnan Provinces were hotspots for trade in whole pangolins and their scales. Interrupting trade in these three principal southern provinces would substantially fragment the pangolin trade network and reduce supply of imports from other south-east Asian countries. In the context of the revised legislation and strategies intended to prevent wildlife trade, we conclude that targeting interventions at key trade nodes could significantly reduce illegal trade in pangolins, and that this approach could also be effective with other taxa
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