198 research outputs found
First-principles Investigation of Thermodynamic Properties of CrNbO4 and CrTaO4
In the present study, the DFT+U method was employed to predict the
thermodynamic properties of Cr2O3, Nb2O5, and Ta2O5. Results were benchmarked
with experimental data showing high accuracy, except for the negative thermal
expansion (NTE) of Nb2O5, which is attributed to its polymorphic complexity.
Additionally, we extended our analysis to rutile-type oxides CrNbO4 and CrTaO4,
examining their entropy and heat capacity at finite temperatures. CrNbO4
displayed slightly higher entropy and heat capacity at high temperatures. The
mean linear thermal expansion coefficients for CrNbO4 and CrTaO4 from 500 K to
2000 K were predicted to be 6.00*10-6/K and 13.49*10-6/K, respectively,
corroborating with DFT predictions and experimental evidence. Our research
highlights the precision of the DFT+U and phonon methods in predicting the
thermodynamic properties of oxide materials, offering insights into the design
of corrosion-resistant materials
ARISTOLOCHIA BRACTEOLATE RETZ. ATTENUATES HYPERURICEMIA IN A METABOLIC ARTHRITIS RAT MODEL
Background: The leaves of Aristolochia bracteolata Retz. has been documented in the folk medicine literature for its anti-arthritic activity. The target of the research envisaged was to elucidate the activity of A. bracteolata extract on hyperuricemic condition in arthritis rat model.
Materials and Methods: Dried and powdered plant leaves were extracted using ether and chloroform. Potassium oxonate was injected intra-articularly to produce arthritis. The hyperuricemic effect, of A. bracteolate was analyzed by studying levels of uric acid in serum as well as in urine of arthritis induced rats. Effects of plant extracts were also studied on BUN (blood urea nitrogen) levels and fraction of uric acid excreted.
Results: Results indicate that administration of A. bracteolata presented substantial change in uric acid concentration, augmented by potassium oxonate administration in rats. The reduction in levels of uric acid levels was nearly same as allopurinol. The investigation also revealed that the primary plant extract has nephroprotective effect by enhancing the production of Prostaglandin E2 and Interleukin-1. Histological studies of rat kidney slices indicated the safety of the present plant extract.
Conclusion: The crude extract of A. bracteolate can be used to reduce hyperuricemia in metabolic arthritis produced in rat model, without inducing any potential damaging effects
Applying hybrid clustering in pulsar candidate sifting with multi-modality for FAST survey
Pulsar search is always the basis of pulsar navigation, gravitational wave
detection and other research topics. Currently, the volume of pulsar candidates
collected by Five-hundred-meter Aperture Spherical radio Telescope (FAST) shows
an explosive growth rate that has brought challenges for its pulsar candidate
filtering System. Particularly, the multi-view heterogeneous data and class
imbalance between true pulsars and non-pulsar candidates have negative effects
on traditional single-modal supervised classification methods. In this study, a
multi-modal and semi-supervised learning based pulsar candidate sifting
algorithm is presented, which adopts a hybrid ensemble clustering scheme of
density-based and partition-based methods combined with a feature-level fusion
strategy for input data and a data partition strategy for parallelization.
Experiments on both HTRU (The High Time Resolution Universe Survey) 2 and FAST
actual observation data demonstrate that the proposed algorithm could
excellently identify the pulsars: On HTRU2, the precision and recall rates of
its parallel mode reach 0.981 and 0.988. On FAST data, those of its parallel
mode reach 0.891 and 0.961, meanwhile, the running time also significantly
decrease with the increment of parallel nodes within limits. So, we can get the
conclusion that our algorithm could be a feasible idea for large scale pulsar
candidate sifting of FAST drift scan observation
The role of vimentin in regulating cell-invasive migration in dense cultures of breast carcinoma cells
Cell migration and mechanics are tightly regulated by the integrated
activities of the various cytoskeletal networks. In cancer cells, cytoskeletal
modulations have been implicated in the loss of tissue integrity, and
acquisition of an invasive phenotype. In epithelial cancers, for example,
increased expression of the cytoskeletal filament protein vimentin correlates
with metastatic potential. Nonetheless, the exact mechanism whereby vimentin
affects cell motility remains poorly understood. In this study, we measured the
effects of vimentin expression on the mechano-elastic and migratory properties
of the highly invasive breast carcinoma cell line MDA231. We demonstrate here
that vimentin stiffens cells and enhances cell migration in dense cultures, but
exerts little or no effect on the migration of sparsely plated cells. These
results suggest that cell-cell interactions play a key role in regulating cell
migration, and coordinating cell movement in dense cultures. Our findings pave
the way towards understanding the relationship between cell migration and
mechanics, in a biologically relevant context.Comment: 26+21 pages, 6+11 figures, supplementary movies available at
http://doi.org/10.6084/m9.figshare.5480149, submitted to Nano Letters journa
Manipulating spatial structure of high-order quantum coherence with entangled photons
High-order quantum coherence reveals the statistical correlation of quantum
particles. Manipulation of quantum coherence of light in temporal domain
enables to produce single-photon source, which has become one of the most
important quantum resources. High-order quantum coherence in spatial domain
plays a crucial role in a variety of applications, such as quantum imaging,
holography and microscopy. However, the active control of high-order spatial
quantum coherence remains a challenging task. Here we predict theoretically and
demonstrate experimentally the first active manipulation of high-order spatial
quantum coherence by mapping the entanglement of spatially structured photons.
Our results not only enable to inject new strength into current applications,
but also provide new possibilities towards more wide applications of high-order
quantum coherence.Comment: 11 pages, 5 figure
Comparison of Ultrasonic and CO2 Laser Pretreatment Methods on Enzyme Digestibility of Corn Stover
To decrease the cost of bioethanol production, biomass recalcitrance needs to be overcome so that the conversion of biomass to bioethanol becomes more efficient. CO2 laser irradiation can disrupt the lignocellulosic physical structure and reduce the average size of fiber. Analyses with Fourier transform infrared spectroscopy, specific surface area, and the microstructure of corn stover were used to elucidate the enhancement mechanism of the pretreatment process by CO2 laser irradiation. The present work demonstrated that the CO2 laser had potential to enhance the bioconversion efficiency of lignocellulosic waste to renewable bioethanol. The saccharification rate of the CO2 laser pretreatment was significantly higher than ultrasonic pretreatment, and reached 27.75% which was 1.34-fold of that of ultrasonic pretreatment. The results showed the impact of CO2 laser pretreatment on corn stover to be more effective than ultrasonic pretreatment
Human cytomegalovirus IE1 downregulates Hes1 in neural progenitor cells as a potential E3 ubiquitin ligase
This work was supported by: National Natural Science Foundation of China http://www.nsfc.gov.cn/; #81620108021: Fetal Brain Maldevelopment Caused by Sox2 Downregulation during Congenital Cytomegalovirus Infection; #31600145: The mechanism of HCMV-IE1 regulating Hes1 expression and rhythm in neural progenitor cells; #81571355: Construction of Murine Cytomegalovirus Derived viral tools for Specific Glia Tracing; #81271850: The regulation mechanism of HCMV infection on Notch signaling pathway in NPCs; and Sino-Africa Joint Research Center, Chinese Academy of Sciences http://www.sinafrica.cas.cn/; #SAJC201605: Geographical distribution and genetic variation of pathogens in Africa. This work is tightly linked to or is an important component of the above list projects, and is financially supported by all the fundings.Congenital human cytomegalovirus (HCMV) infection is the leading cause of neurological disabilities in children worldwide, but the mechanisms underlying these disorders are far from well-defined. HCMV infection has been shown to dysregulate the Notch signaling pathway in human neural progenitor cells (NPCs). As an important downstream effector of Notch signaling, the transcriptional regulator Hairy and Enhancer of Split 1 (Hes1) is essential for governing NPC fate and fetal brain development. In the present study, we report that HCMV infection downregulates Hes1 protein levels in infected NPCs. The HCMV 72-kDa immediate-early 1 protein (IE1) is involved in Hes1 degradation by assembling a ubiquitination complex and promoting Hes1 ubiquitination as a potential E3 ubiquitin ligase, followed by proteasomal degradation of Hes1. Sp100A, an important component of PML nuclear bodies, is identified to be another target of IE1-mediated ubiquitination. A C-terminal acidic region in IE1, spanning amino acids 451 to 475, is required for IE1/Hes1 physical interaction and IE1-mediated Hes1 ubiquitination, but is dispensable for IE1/Sp100A interaction and ubiquitination. Our study suggests a novel mechanism linking downregulation of Hes1 protein to neurodevelopmental disorders caused by HCMV infection. Our findings also complement the current knowledge of herpesviruses by identifying IE1 as the first potential HCMV-encoded E3 ubiquitin ligase.Publisher PDFPeer reviewe
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