2,798 research outputs found
The Effect of Nano-Aluminumpowder on the Characteristic of RDX based Aluminized Explosives Underwater Close-Filed Explosion
In order to investigate the effect of nano-aluminum powder on the characteristic of RDX based aluminized explosives underwater closed-filed explosions, the scanning photographs along the radial of the charges were gained by a high speed scanning camera. The photographs of two different aluminized explosives underwater explosion have been analyzed, the shock wave curves and expand curves of detonation products were obtained, furthermore the change rules of shock waves propagation velocity, shock front pressure and expansion of detonation products of two aluminized explosives were investigated, and also the parameters of two aluminized explosives were contrasted. The results show that the aluminized explosive which with nano-aluminum whose initial shock waves pressure propagation velocity, shock front pressure are smaller than the aluminized explosive without nano-aluminum and has lower decrease rate attenuation of energy
Dynamic Evolution of Eukaryotic Mitochondrial and Nuclear Genomes: A Case Study in the Gourmet Pine Mushroom Tricholoma matsutake
Fungi, as eukaryotic organisms, contain two genomes, the mitochondrial genome and the nuclear genome, in their cells. How the two genomes evolve and correlate to each other is debated. Herein, taking the gourmet pine mushroom Tricholoma matsutake as an example, we performed comparative mitogenomic analysis using samples collected from diverse locations and compared the evolution of the two genomes. The T. matsutake mitogenome encodes 49 genes and is rich of repetitive and non-coding DNAs. Six genes were invaded by up to 11 group I introns, with one cox1 intron cox1P372 showing presence/absence dynamics among different samples. Bioinformatic analyses suggested limited or no evidence of mitochondrial heteroplasmy. Interestingly, hundreds of mitochondrial DNA fragments were found in the nuclear genome, with several larger than 500 nt confirmed by PCR assays and read count comparisons, indicating clear evidence of transfer of mitochondrial DNA into the nuclear genome. Nuclear DNA of T. matsutake showed a higher mutation rate than mitochondrial DNA. Furthermore, we found evidence of incongruence between phylogenetic trees derived from mitogenome and nuclear DNA sequences. Together, our results reveal the dynamic genome evolution of the gourmet pine mushroom.Peer reviewe
AquaÂ[1-(1,10-phenanthrolin-2-yl-κ2 N,N′)-1H-pyrazol-3-amine-κN 2](sulfato-κO)copper(II) methanol monosolvate dihydrate
In the title compound, [Cu(SO4)(C15H11N5)(H2O)]·CH3OH·2H2O, the CuII ion is in a distorted square-pyramidal geometry, in which three N atoms from the chelating 1-(1,10-phenanthrolin-2-yl)-1H-pyrazol-3-amine ligand and one O atom from a sulfate anion define the basal plane and the O atom from the coordinating water molÂecule is located at the apex. In the crystal, hydrogen-bonding interÂactions involving the coordinating and solvent water molÂecules, the methanol solvent molÂecule and the amine group (one with an intraÂmolecular interÂaction to one of the sulfate O atoms) of the complex are observed. π–π interÂactions between symmetry-related phenantroline moieties, with a shortest centroid–centroid interÂaction of 3.573 (2)°, are also present
Recent progress in metabolic reprogramming in gestational diabetes mellitus: a review
Gestational diabetes mellitus is a prevalent metabolic disease that can impact the normal course of pregnancy and delivery, leading to adverse outcomes for both mother and child. Its pathogenesis is complex and involves various factors, such as insulin resistance and β-cell dysfunction. Metabolic reprogramming, which involves mitochondrial oxidative phosphorylation and glycolysis, is crucial for maintaining human metabolic balance and is involved in the pathogenesis and progression of gestational diabetes mellitus. However, research on the link and metabolic pathways between metabolic reprogramming and gestational diabetes mellitus is limited. Therefore, we reviewed the relationship between metabolic reprogramming and gestational diabetes mellitus to provide new therapeutic strategies for maternal health during pregnancy and reduce the risk of developing gestational diabetes mellitus
Phylogenetic Analyses of Plastid-Originated Proteins Imply Universal Endosymbiosis in Ancestors of Animals and Fungi
We searched and analyzed cyanobacteria-originated metazoa/fungi proteins (COPs) by phylogenetic analyses. Analysis of them showed that for millions of years universal plastid endosymbiosis and gene transfer occurred in ancestors of metazoa/fungi, and some transferred fragments have been reserved until now even in modern mammals. Most eukaryotes contained plastids in the ancient era, and some of them lost them later. Functions of homologues in cyanobacterial genomes and eukaryotic genomes are in consensus, and most are involved in the organic compound metabolism. With emergence of organelles and subcellular structure in eukaryotic cells, the locations of these proteins diversified. Furthermore, some novel functions were endowed for COPs, especially in vertebrates
Growth factor receptor-Src-mediated suppression of GRK6 dysregulates CXCR4 signaling and promotes medulloblastoma migration
BACKGROUND: Metastasis in medulloblastoma (MB) is associated with poor survival. Recent genetic studies revealed MB to comprise distinct molecular subgroups, including the sonic hedgehog (SHH) subgroup that exhibits a relatively high rate of progression. To identify targeted therapeutics against metastasis, a better understanding of the regulation of MB cell migration is needed. G protein-coupled receptor kinases (GRKs) have been implicated in cancer metastasis through their regulation of G-protein coupled receptors (GPCRs) involved in growth factor (GF)-mediated cell migration. However, the specific roles and regulation of GRKs in MB have not been investigated. METHODS: Microarray mRNA analysis was performed for GRKs, GPCRs, and GFs in 29 human MB, and real time RT-PCR was used to detect GRK6 expression in MB cells. Lenti- or retro-virus infection, and siRNA or shRNA transfection, of MB cells was used to overexpress and knockdown target genes, respectively. Western blot was used to confirm altered expression of proteins. The effect of altered target protein on cell migration was determined by Boyden chamber assay and xCELLigence migration assays. RESULTS: We observed co-overexpression of PDGFRA, CXCR4, and CXCL12 in the SHH MB subtype compared to non-SHH MB (5, 7, and 5-fold higher, respectively). GRK6, which typically acts as a negative regulator of CXCR4 signaling, is downregulated in MB, relative to other GRKs, while the percentage of GRK6 expression is lower in MB tumors with metastasis (22%), compared to those without metastasis (43%). In SHH-responsive MB cells, functional blockade of PDGFR abolished CXCR4-mediated signaling. shPDGFR transfected MB cells demonstrated increased GRK6 expression, while PDGF or 10% FBS treatment of native MB cells reduced the stability of GRK6 by inducing its proteosomal degradation. Overexpression or downregulation of Src, a key mediator of GF receptor/PDGFR signaling, similarly inhibited or induced GRK6 expression, respectively. siRNA downregulation of GRK6 enhanced CXCR4 signaling and promoted MB migration, while lentiviral-GRK6 overexpression suppressed CXCR4 signaling, potentiated the effect of AMD3100, a CXCR4 antagonist, and impaired migration. CONCLUSIONS: Our findings demonstrate a novel mechanism of GF receptor/PDGFR-Src-mediated dysregulation of CXCR4 signaling that promotes MB cell migration, which could potentially be exploited for therapeutic targeting in SHH MB
Prediction of Giant Tunneling Magnetoresistance in RuO/TiO/RuO (110) Antiferromagnetic Tunnel Junctions
Using first-principles quantum-transport calculations, we investigate
spin-dependent electronic and transport properties of antiferromagnetic tunnel
junctions (AFMTJs) that consist of (110)-oriented antiferromagnetic (AFM) metal
RuO electrodes and an insulating TiO tunneling barrier. We predict
the emergence of a giant tunneling magnetoresistance (TMR) effect in a wide
energy window, a series of barrier layer thicknesses, and different interface
terminations, indicating the robustness of this effect. We show that the
predicted TMR cannot be explained in terms of the global transport
spin-polarization of RuO (110) but is well understood based on matching
the momentum-dependent spin-polarized conduction channels of the two RuO
(110) electrodes. We predict oscillations of TMR with increasing barrier
thickness, indicating a non-negligible contribution from the perfectly
epitaxial interfaces. Our work helps the understanding of the physics of TMR in
AFMTJs and aids in realizing efficient AFM spintronic devices
Antibacterial Activity and Mode of Action of Mentha arvensis Ethanol Extract against Multidrug-Resistant Acinetobacter baumannii
Purpose: To evaluate the antibacterial effect of ethanol extract of Mentha arvensis against multi-drug resistant Acinetobacter baumannii using liquid chromatography–mass spectrometry (LC-ESI-MS).Methods: Disc diffusion and microdilution assays were used to evaluate the antibacterial effect of the extract by measuring the zone of inhibition, minimum inhibitory concentration (MIC) and and minimum bacteriocidal concentration (MBC) of the extract against the test bacteria. Scanning electron microscopy (SEM) was employed to evaluate the morphological changes induced by the extract in cellular membrane of the bacteria. Reactive oxygen species (ROS) generation and protein leakage from the bacterial cells induced by the extract were also evaluated.Results: The extract showed dose-dependent growth inhibitory effects against A. baumannii with MIC and MBC of 23.5 and 72.1 μg/mL, respectively. The extract also induced potent ROS generation and protein leakage in A. baumannii bacterial cells. SEM findings revealed that the extract induced potential cellular damage which increased with increasing extract concentration.Conclusion: The ethanol extract of Mentha arvensis is a potent antibacterial agent against A. baumannii and acts by inducing lethal cellular damage to the bacterium.Keywords: Mentha arvensis, Acinetobacter baumannii, Reactive oxygen species, Antibacterial activity, Cellular membrane damag
SGDFormer: One-stage Transformer-based Architecture for Cross-Spectral Stereo Image Guided Denoising
Cross-spectral image guided denoising has shown its great potential in
recovering clean images with rich details, such as using the near-infrared
image to guide the denoising process of the visible one. To obtain such image
pairs, a feasible and economical way is to employ a stereo system, which is
widely used on mobile devices. Current works attempt to generate an aligned
guidance image to handle the disparity between two images. However, due to
occlusion, spectral differences and noise degradation, the aligned guidance
image generally exists ghosting and artifacts, leading to an unsatisfactory
denoised result. To address this issue, we propose a one-stage
transformer-based architecture, named SGDFormer, for cross-spectral Stereo
image Guided Denoising. The architecture integrates the correspondence modeling
and feature fusion of stereo images into a unified network. Our transformer
block contains a noise-robust cross-attention (NRCA) module and a spatially
variant feature fusion (SVFF) module. The NRCA module captures the long-range
correspondence of two images in a coarse-to-fine manner to alleviate the
interference of noise. The SVFF module further enhances salient structures and
suppresses harmful artifacts through dynamically selecting useful information.
Thanks to the above design, our SGDFormer can restore artifact-free images with
fine structures, and achieves state-of-the-art performance on various datasets.
Additionally, our SGDFormer can be extended to handle other unaligned
cross-model guided restoration tasks such as guided depth super-resolution
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