2,245 research outputs found
5-Methyl-3,3-bis(4-methylpiperazin-1-yl)-1-[2-(4-methylpiperazin-1-yl)ethyl]indolin-2-one
In the title compound, C26H43N7O, each piperazine ring adopts a chair conformation. Two 1-methylpiperazine rings bond to one Csp
3 of the pyrrole ring via the piperazine N atoms, while the third one links to the N atom of the indolin-2-one unit through a flexible ethyl group with an almost syn conformation. In the crystal, molecules are connected through methylene–carbonyl C—H⋯O interactions into an infinite chain along the c axis. The almost parallel arrays are stacked, forming a three-dimensional framework
Progress and Development Trend of Space Intelligent Robot Technology
Since space intelligent robots are not restricted by physiological conditions, it is an attractive choice for the development of automation technology to use them for space exploration and utilization. It is currently the key development direction of the major space powers over the world. This paper first investigates the robotic manipulators and humanoid robot systems for space station applications and reviews theories and methods for robots to achieve large-range stable motion and intelligent dexterous manipulation. Then, the intelligent robot systems for on-orbit satellite maintenance are reviewed, and the related technologies of multirobot collaboration are analyzed. Finally, we investigate the intelligent robot systems for on-orbit assembly of large-scale spatial structures and summarize the technologies of modular assembly and on-orbit manufacture. Overall, this paper reviews the technological progress and development trends of space robots, which provides a good reference for further technical research in this field
ViT-CX: Causal Explanation of Vision Transformers
Despite the popularity of Vision Transformers (ViTs) and eXplainable AI
(XAI), only a few explanation methods have been proposed for ViTs thus far.
They use attention weights of the classification token on patch embeddings and
often produce unsatisfactory saliency maps. In this paper, we propose a novel
method for explaining ViTs called ViT-CX. It is based on patch embeddings,
rather than attentions paid to them, and their causal impacts on the model
output. ViT-CX can be used to explain different ViT models. Empirical results
show that, in comparison with previous methods, ViT-CX produces more meaningful
saliency maps and does a better job at revealing all the important evidence for
prediction. It is also significantly more faithful to the model as measured by
deletion AUC and insertion AUC
(E)-2-(Cyclohexylmethylene)succinic acid
The title compound, C11H16O4, crystallizes with three molecules in the asymmetric unit. The cyclohexane ring adopts a chair conformation. Intermolecular O—H⋯O hydrogen bonds are observed and these help to establish the crystal packing
Anti-tumor effects of ephedrine and anisodamine on SKBR3 human breast cancer cell line
Background: To investigate the effects of ephedrine and anisodamine on the proliferation of human breast cancer.Materials and Methods: SKBR3 cell was treated with or without ephedrine and / or anisodamine, respectively. The trypan blue exclusion assay was used to determine cell numbers. Flow cytometry was used to assess cell cycle distribution and apoptosis. The concentration of cAMP and cyclin D1 was analyzed by enzyme-linked immunosorbent assay. Western blot was used to measure PKA.Results: Ephedrine and anisodamine inhibited cell proliferation and arrested SKBR3 cells at G0/G1 phases. Ephedrine and anisodamine increased the level of CD1 in SKBR3 cells. Furthermore, significant change in intracellular cAMP concentration was found in SKBR3 cells treated with ephedrine and anisodamine. The phosphorylation of PKA substrate was not activated after 48 hours of treatment with ephedrine and anisodamine.Conclusion: Ephedrine and anisodamine inhibit the proliferation of SKBR3 cells via a significantly change of intracellular cAMP concentration.Key words: anisodamine, breast cancer, cyclic adenosine monophosphate, ephedrine, proliferation Abbreviations: cAMP, cyclic adenosine monophosphate; TCM, traditional Chinese medicine; ELISA, enzyme-linked immunosorbent assay; CD1, cyclin D1; SNS, sympathetic nervous system
Surface-Based Regional Homogeneity in First-Episode, Drug-Naive Major Depression: A Resting-State fMRI Study
Background. Previous volume-based regional homogeneity (ReHo) studies neglected the intersubject variability in cortical folding patterns. Recently, surface-based ReHo was developed to reduce the intersubject variability and to increase statistical power. The present study used this novel surface-based ReHo approach to explore the brain functional activity differences between first-episode, drug-naive MDD patients and healthy controls. Methods. Thirty-three first-episode, drug-naive MDD patients and 32 healthy controls participated in structural and resting-state fMRI scans. MDD patients were rated with a 17-item Hamilton Rating Scale for Depression prior to the scan. Results. In comparison with the healthy controls, MDD patients showed reduced surface-based ReHo in the left insula. There was no increase in surface-based ReHo in MDD patients. The surface-based ReHo value in the left insula was not significantly correlated with the clinical information or the depressive scores in the MDD group. Conclusions. The decreased surface-based ReHo in the left insula in MDD may lead to the abnormal top-down cortical-limbic regulation of emotional and cognitive information. The surface-based ReHo may be a useful index to explore the pathophysiological mechanism of MDD.</p
Optical loss compensation in a bulk left-handed metamaterial by the gain in quantum dots
A bulk left-handed metamaterial with fishnet structure is investigated to
show the optical loss compensation via surface plasmon amplification, with the
assistance of a Gaussian gain in PbS quantum dots. The optical resonance
enhancement around 200 THz is confirmed by the retrieval method. By exploring
the dependence of propagation loss on the gain coefficient and metamaterial
thickness, we verify numerically that the left-handed response can endure a
large propagation thickness with ultralow and stable loss under a certain gain
coefficient.Comment: 6 pages with 4 figure
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