3,835 research outputs found
(6E)-N-[(4Z)-2,5-Dimethyl-4-(p-tolylimino)cyclohexa-2,5-dienylidene]-4-methylaniline
The title compound, C22H22N2, was prepared by the reaction of 4-aminotoluene with sodium carbonate, sodium hydroxide and potassium permanganate. The molecule is disposed about a crystallographic inversion centre with one half-molecule comprising the asymmetric unit. The dihedral angle between the terminal and central benzene rings is 88.05 (1)°. The crystal packing is stabilized by van der Waals forces
An optimal scaling scheme for DCO-OFDM based visible light communications
DC-biased optical orthogonal frequency-division multiplexing (DCO-OFDM) is widely used in visible light communication (VLC) systems to provide high data rate transmission. As intensity modulation with direct detection (IM/DD) is employed to modulate the OFDM signal, scale up the amplitude of the signal can increase the effective transmitted electrical power whereas more signals are likely to be clipped due to the limited dynamic range of LEDs, resulting in severe clipping distortion. Thus, it is crucial to scale the signal to find a tradeoff between the effective electrical power and the clipping distortion. In this paper, an optimal scaling scheme is proposed to maximize the received signal-to-noise-plus-distortion ratio (SNDR) with the constraint of the radiated optical power in a practical scenario where DC bias is fixed for a desired dimming level. Simulation results show that the system with the optimal scaling factor outperforms that with fixed scaling factor under different equivalent noise power in terms of the bit error ratio (BER) performance
The physical properties of Fermi-4LAC low-synchrotron-peaked BL Lac objects
Previous studies on the fitting of spectral energy distributions (SEDs) often
apply the external-Compton process to interpret the high-energy peak of
low-synchrotron-peaked (LSP) BL Lac objects (LBLs), despite the lack of strong
broad emission lines observed for LBLs. In this work, we collect
quasi-simultaneous multi-wavelength data of 15 LBLs from the Fermi fourth LAT
AGN catalog (4LAC). We propose an analytical method to assess the necessity of
external photon fields in the framework of one-zone scenario. Following derived
analytical results, we fit the SEDs of these LBLs with the conventional
one-zone leptonic model and study their jet physical properties. Our main
results can be summarized as follows. (1)We find that most LBLs cannot be
fitted by the one-zone synchrotron self-Compton (SSC) model. This indicates
that external photons play a crucial role in the high-energy emission of LBLs,
therefore we suggest that LBLs are masquerading BL Lacs. (2) We suggest that
the -ray emitting regions of LBLs are located outside the broad-line
region and within the dusty torus. (3) By extending the analytical method to
all types of LSPs in Fermi-4LAC (using historical data), we find that the
high-energy peaks of some flat spectrum radio quasars and blazar candidates of
unknown types can be attributed to the SSC emission, implying that the
importance of external photons could be minor. We suggest that the variability
timescale may help distinguish the origin of the high-energy peak.Comment: Accepted for publication in MNRAS (14 pages, 7 figures, 2 tables
GOPlan: Goal-conditioned Offline Reinforcement Learning by Planning with Learned Models
Offline goal-conditioned RL (GCRL) offers a feasible paradigm to learn
general-purpose policies from diverse and multi-task offline datasets. Despite
notable recent progress, the predominant offline GCRL methods have been
restricted to model-free approaches, constraining their capacity to tackle
limited data budgets and unseen goal generalization. In this work, we propose a
novel two-stage model-based framework, Goal-conditioned Offline Planning
(GOPlan), including (1) pretraining a prior policy capable of capturing
multi-modal action distribution within the multi-goal dataset; (2) employing
the reanalysis method with planning to generate imagined trajectories for
funetuning policies. Specifically, the prior policy is based on an
advantage-weighted Conditioned Generative Adversarial Networks that exhibits
distinct mode separation to overcome the pitfalls of out-of-distribution (OOD)
actions. For further policy optimization, the reanalysis method generates
high-quality imaginary data by planning with learned models for both
intra-trajectory and inter-trajectory goals. Through experimental evaluations,
we demonstrate that GOPlan achieves state-of-the-art performance on various
offline multi-goal manipulation tasks. Moreover, our results highlight the
superior ability of GOPlan to handle small data budgets and generalize to OOD
goals.Comment: Spotlight Presentation at Goal-conditioned Reinforcement Learning
Workshop at NeurIPS, 202
Scoulerine promotes cytotoxicity and attenuates stemness in ovarian cancer by targeting PI3K/AKT/mTOR axis
In women, ovarian cancer is a common gynecological cancer associated with poor prognosis, reoccurrence and chemoresistance. Scoulerine, a benzylisoquinoline alkaloid, has been reported effective against several carcinomas. Thus, we investigated the impact of scoulerine on ovarian cancer cells (OVCAR3). Cell viability was assessed by MTT assay, migration was determined by Boyden Chamber assay, while the invasion was monitored by Boyden Chamber assay using the matrigel. The stemness properties of OVCAR3 cells were observed by tumorsphere assay. Epithelial to mesenchymal transition (EMT) and stemness-related protein markers were monitored by real-time PCR analysis and immunoblotting. Scoulerine inhibits the viability of OVCAR3 cells with the IC50 observed at 10 µmol L–1 after 48 h treatment. Scoulerine inhibited the colony-forming ability, migration and invasiveness of OVCAR3 cells in a dose-dependent fashion. Scoulerine treatment also drastically reduced the spheroid-forming ability of OVCAR3 cells. The mesenchymal and stemness-related markers like N-cadherin, vimentin, CD-44, Oct-4, Sox-2 and Aldh1A1 were downregulated, whereas the epithelial markers like E-cadherin and CD-24 were upregulated in scoulerine-treated cells. The upstream PI3K/Akt/mTOR-axis was downregulated in scoulerine-treated cells. We concluded that scoulerine successfully perturbs the cancerous properties of OVCAR3 cells by targeting the PI3K/Akt/mTOR axis. In vivo studies revealed a substantial decrease in tumor mass and volume after scoulerine treatment. Furthermore, scoulerine treatment was found to decrease oxidative stress factors in ovarian cancer mice model. Scoulerine is a potential anticancer agent against ovarian cancer and can be considered as a lead molecule for this malignancy, provided further investigations are performed
First-principles design of ferromagnetic monolayer MnO at the complex interface
Rapidly increasing interest in low-dimensional materials is driven by the
emerging requirement to develop nanoscale
solid-state devices with novel functional properties that are not available
in three-dimensional bulk phases.
Among the well-known low-dimensional systems, complex transition metal oxide
interface holds promise for broad
applications in electronic and spintronics devices. Herein, intriguing
metal-insulator and
ferromagnetic-antiferromagnetic transitions are achieved in monolayer MnO
that is sandwiched into
SrTiO-based heterointerface systems through interface engineering.
By using first-principles calculations, we modeled three types of
SrTiO-based heterointerface systems with different interface terminations
and performed a comparative study on the spin-dependent magnetic and electronic
properties that are established in the confined MnO monolayer.
First-principles study predicts that metal-insulator transition and magnetic
transition in the monolayer MnO are independent on the thickness of capping
layers. Moreover, 100 spin-polarized two-dimensional electron gases
accompanied by robust room temperature magnetism are uncovered in the monolayer
MnO. Not only is the buried MnO monolayer a new interface phase of
fundamental physical interest, but it is also a promising candidate material
for nanoscale spintronics applications. Our study suggests interface
engineering at complex oxide interfaces is an alternative approach to designing
high-performance two-dimensional materials.Comment: 24 pages, 7 figure
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