194 research outputs found
Asparagine promotes cancer cell proliferation through use as an amino acid exchange factor.
Cellular amino acid uptake is critical for mTOR complex 1 (mTORC1) activation and cell proliferation. However, the regulation of amino acid uptake is not well-understood. Here we describe a role for asparagine as an amino acid exchange factor: intracellular asparagine exchanges with extracellular amino acids. Through asparagine synthetase knockdown and altering of media asparagine concentrations, we show that intracellular asparagine levels regulate uptake of amino acids, especially serine, arginine and histidine. Through its exchange factor role, asparagine regulates mTORC1 activity and protein synthesis. In addition, we show that asparagine regulation of serine uptake influences serine metabolism and nucleotide synthesis, suggesting that asparagine is involved in coordinating protein and nucleotide synthesis. Finally, we show that maintenance of intracellular asparagine levels is critical for cancer cell growth. Collectively, our results indicate that asparagine is an important regulator of cancer cell amino acid homeostasis, anabolic metabolism and proliferation
Accurate Localization of 3D Objects from RGB-D Data Using Segmentation Hypotheses
In this paper we focus on the problem of detecting ob-jects in 3D from RGB-D images. We propose a novel frame-work that explores the compatibility between segmentation hypotheses of the object in the image and the corresponding 3D map. Our framework allows to discover the optimal lo-cation of the object using a generalization of the structural latent SVM formulation in 3D as well as the definition of a new loss function defined over the 3D space in training. We evaluate our method using two existing RGB-D datasets. Extensive quantitative and qualitative experimental results show that our proposed approach outperforms state-of-the-art as methods well as a number of baseline approaches for both 3D and 2D object recognition tasks. 1
Research on Adaptive Neural Network Control System Based on Nonlinear U-Model with Time-Varying Delay
U-model can approximate a large class of smooth nonlinear time-varying delay system to any accuracy by using time-varying delay parameters polynomial. This paper proposes a new approach, namely, U-model approach, to solving the problems of analysis and synthesis for nonlinear systems. Based on the idea of discrete-time U-model with time-varying delay, the identification algorithm of adaptive neural network is given for the nonlinear model. Then, the controller is designed by using the Newton-Raphson formula and the stability analysis is given for the closed-loop nonlinear systems. Finally, illustrative examples are given to show the validity and applicability of the obtained results
Comparisons of methods for linkage analysis and haplotype reconstruction using extended pedigree data
We compare and contrast the performance of SIMPLE, a Monte Carlo based software, with that of several other methods for linkage and haplotype analyses, focusing on the simulated data from the New York City population. First, a whole-genome scan study based on the microsatellite markers was performed using GENEHUNTER. Because GENEHUNTER had to drop individuals for many of the pedigrees, we performed a follow-up study focusing on several regions of interest using SIMPLE, which can handle all pedigrees in their entirety. Second, 3 haplotyping programs, including that in SIMPLE, were used to reconstruct haplotypic configurations in pedigrees. SIMPLE emerges clearly as a preferred tool, as it can handle large pedigrees and produces haplotypic configurations without double recombinant haplotypes. For this study, we had knowledge of the simulating models at the time we performed the analysis
Jasmine (Jasminum grandiflorum) Flower Extracts Ameliorate Tetradecanoylphorbol Acetate Induced Ear Edema in Mice
Published data from in vitro assays support the anti-inflammatory effects of jasmine (Jasminum grandiflorum Linn.) but limited studies are reported in animal models. Herein, the anti-inflammatory effects of jasmine flower extracts (JFEs) including ethanol extract (JF-EE), petroleum ether extract (JF-PEE), ethyl acetate extract (JF-EAE), and n-butanol extract (JF-BE) were evaluated in a mouse ear edema model. Acute mouse ear skin inflammation was induced by tetradecanoylphorbol acetate (TPA; 125 µg/mL) and then treated with JFEs (100 mg/mL) or dexamethasone (DEX; 6.25 mg/mL; as a positive control). Jasmine flower extracts alleviated ear edema by reducing TPA-increased ear thickness and ear weight by 30.8% to 64.1% and 24.0% to 47.1%, respectively, whereas DEX showed comparable activity (by 71.8% and 49.1%, respectively). Their anti-inflammatory effects were supported by data from the immunohistochemical assays. Jasmine flower extracts reduced the inflammatory cells (from 5.5- to 9.5-fold) and the expressions of inflammation related enzymes including cyclooxygenase-2 and inhibitor of kappa-B kinase (from 1.9- to 2.8-fold and from 7.1- to 11.0-fold, respectively). Findings from this study showed that JFEs were able to ameliorate TPA-induced mouse skin inflammation. However, future studies on the underlying mechanisms of jasmine flower’s anti-inflammatory effects are warranted
Adaptive Neural Back-Stepping Control with Constrains for a Flexible Air-Breathing Hypersonic Vehicle
The design of an adaptive neural back-stepping control for a flexible air-breathing hypersonic vehicle (AHV) in the presence of input constraint and aerodynamic uncertainty is discussed. Based on functional decomposition, the dynamics can be decomposed into the velocity subsystem and the altitude subsystem. To guarantee the exploited controller’s robustness with respect to parametric uncertainties, neural network (NN) is applied to approximate the lumped uncertainty of each subsystem of AHV model. The exceptional contribution is that novel auxiliary systems are introduced to compensate both the tracking errors and desired control laws, based on which the explored controller can still provide effective tracking of velocity and altitude commands when the actuators are saturated. Finally, simulation studies are made to illustrate the effectiveness of the proposed control approach in spite of the flexible effects, system uncertainties, and varying disturbances
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Chronic IL-1β-induced inflammation regulates epithelial-to-mesenchymal transition memory phenotypes via epigenetic modifications in non-small cell lung cancer.
Chronic inflammation facilitates tumor progression. We discovered that a subset of non-small cell lung cancer cells underwent a gradually progressing epithelial-to-mesenchymal (EMT) phenotype following a 21-day exposure to IL-1β, an abundant proinflammatory cytokine in the at-risk for lung cancer pulmonary and the lung tumor microenvironments. Pathway analysis of the gene expression profile and in vitro functional studies revealed that the EMT and EMT-associated phenotypes, including enhanced cell invasion, PD-L1 upregulation, and chemoresistance, were sustained in the absence of continuous IL-1β exposure. We referred to this phenomenon as EMT memory. Utilizing a doxycycline-controlled SLUG expression system, we found that high expression of the transcription factor SLUG was indispensable for the establishment of EMT memory. High SLUG expression in tumors of lung cancer patients was associated with poor survival. Chemical or genetic inhibition of SLUG upregulation prevented EMT following the acute IL-1β exposure but did not reverse EMT memory. Chromatin immunoprecipitation and methylation-specific PCR further revealed a SLUG-mediated temporal regulation of epigenetic modifications, including accumulation of H3K27, H3K9, and DNA methylation, in the CDH1 (E-cadherin) promoter following the chronic IL-1β exposure. Chemical inhibition of DNA methylation not only restored E-cadherin expression in EMT memory, but also primed cells for chemotherapy-induced apoptosis
Supercurrent, Multiple Andreev Reflections and Shapiro Steps in InAs Nanosheet Josephson Junctions
High-quality free-standing InAs nanosheets are emerging layered semiconductor
materials with potentials in designing planar Josephson junction devices for
novel physics studies due to their unique properties including strong
spin-orbit couplings, large Land\'e g-factors and the two dimensional nature.
Here, we report an experimental study of proximity induced superconductivity in
planar Josephson junction devices made from free-standing InAs nanosheets. The
nanosheets are grown by molecular beam epitaxy and the Josephson junction
devices are fabricated by directly contacting the nanosheets with
superconductor Al electrodes. The fabricated devices are explored by
low-temperature carrier transport measurements. The measurements show that the
devices exhibit a gate-tunable supercurrent, multiple Andreev reflections, and
a good quality superconductor-semiconductor interface. The superconducting
characteristics of the Josephson junctions are investigated at different
magnetic fields and temperatures, and are analyzed based on the
Bardeen-Cooper-Schrieffer (BCS) theory. The measurements of ac Josephson effect
are also conducted under microwave radiations with different radiation powers
and frequencies, and integer Shapiro steps are observed. Our work demonstrates
that InAs nanosheet based hybrid devices are desired systems for investigating
forefront physics, such as the two-dimensional topological superconductivity
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Author Correction: Chronic IL-1β-induced inflammation regulates epithelial-to-mesenchymal transition memory phenotypes via epigenetic modifications in non-small cell lung cancer.
An amendment to this paper has been published and can be accessed via a link at the top of the paper
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