This paper proposes a framework to perform the sensor classification by using multivariate time series sensors data as inputs. The framework encodes multivariate time series data into two-dimensional ...colored images, and concatenate the images into one bigger image for classification through a Convolutional Neural Network (ConvNet). This study applied three transformation methods to encode time series into images: Gramian Angular Summation Field (GASF), Gramian Angular Difference Field (GADF), and Markov Transition Field (MTF). Two open multivariate datasets were used to evaluate the impact of using different transformation methods, the sequences of concatenating images, and the complexity of ConvNet architectures on classification accuracy. The results show that the selection of transformation methods and the sequence of concatenation do not affect the prediction outcome significantly. Surprisingly, the simple structure of ConvNet is sufficient enough for classification as it performed equally well with the complex structure of VGGNet. The results were also compared with other classification methods and found that the proposed framework outperformed other methods in terms of classification accuracy.
Reversible post-translational modifications represent a mechanism to control tumor metabolism. Here we show that mitochondrial Sirtuin5 (SIRT5), which mediates lysine desuccinylation, ...deglutarylation, and demalonylation, plays a role in colorectal cancer (CRC) glutamine metabolic rewiring. Metabolic profiling identifies that deletion of SIRT5 causes a marked decrease in
C-glutamine incorporation into tricarboxylic-acid (TCA) cycle intermediates and glutamine-derived non-essential amino acids. This reduces the building blocks required for rapid growth. Mechanistically, the direct interaction between SIRT5 and glutamate dehydrogenase 1 (GLUD1) causes deglutarylation and functional activation of GLUD1, a critical regulator of cellular glutaminolysis. Consistently, GLUD1 knockdown diminishes SIRT5-induced proliferation, both in vivo and in vitro. Clinically, overexpression of SIRT5 is significantly correlated with poor prognosis in CRC. Thus, SIRT5 supports the anaplerotic entry of glutamine into the TCA cycle in malignant phenotypes of CRC via activating GLUD1.
Tumor cells evade T cell-mediated immunosurveillance via the interaction between programmed death-1 (PD-1) ligand 1 (PD-L1) on tumor cells and PD-1 on T cells. Strategies disrupting PD-1/PD-L1 have ...shown clinical benefits in various cancers. However, the limited response rate prompts us to investigate the molecular regulation of PD-L1. Here, we identify trafficking protein particle complex subunit 4 (TRAPPC4), a major player in vesicular trafficking, as a crucial PD-L1 regulator. TRAPPC4 interacts with PD-L1 in recycling endosomes, acting as a scaffold between PD-L1 and RAB11, and promoting RAB11-mediated recycling of PD-L1, thus replenishing its distribution on the tumor cell surface. TRAPPC4 depletion leads to a significant reduction of PD-L1 expression in vivo and in vitro. This reduction in PD-L1 facilitates T cell-mediated cytotoxicity. Overexpression of Trappc4 sensitizes tumor cells to checkpoint therapy in murine tumor models, suggesting TRAPPC4 as a therapeutic target to enhance anti-tumor immunity.
Melatonin is a biological hormone that plays crucial roles in stress tolerance. In this study, we investigated the effect of exogenous melatonin on abiotic stress in the tea plant. Under cold, salt ...and drought stress, increasing malondialdehyde levels and decreasing maximum photochemical efficiency of PSII were observed in tea leaves. Meanwhile, the levels of reactive oxygen species (ROS) increased significantly under abiotic stress. Interestingly, pretreatment with melatonin on leaves alleviated ROS burst, decreased malondialdehyde levels and maintain high photosynthetic efficiency. Moreover, 100 μM melatonin-pretreated tea plants showed high levels of glutathione and ascorbic acid and increased the activities of superoxide dismutase, peroxidase, catalase and ascorbate peroxidase under abiotic stress. Notably, melatonin treatments can positively up-regulate the genes (
,
,
and
) expression of antioxidant enzyme biosynthesis. Taken together, our results confirmed that melatonin protects tea plants against abiotic stress-induced damages through detoxifying ROS and regulating antioxidant systems.
•A continuum model is proposed for the unusual mechanical behavior of liquid crystal elastomers based on dissipation principle for viscoelastic solids with micro order.•Contribution of ...Ericksen–Lesilie stress can make the total Cauchy stress asymmetric and result in a torque to reorient the alignment of liquid crystal.•The balance equations of momentum and micro order can be solved numerically using commercial finite element software without much difficulty.•Numerical solutions confirm the possible appearance of stripe domains and agree quite well with experiments.
Liquid crystal elastomers (LCEs) are special cross-linked polymer materials combining the large elastic deformability of elastomers with the orientational orders of liquid crystals. Here we develop a general framework of LCEs in the language of continuum mechanics to consider the interaction of polymer backbone and Liquid Crystal (LC) microstructure, which is suitable for large deformation and large director rotation. Based on the dissipation principle, the balance of momentum and the evolution equations of orientational order are obtained. In addition to the deformation and its time derivative, the basic kinematic ingredients of this theory are identical to those arising in the director theories and the order tensor theories for nematic fluids. The Cauchy stress consists of not only the bulk stress contribution of the backbone but also the Ericksen–Leslie stress of LC and the obtained rotational momentum balance implies the asymmetric Cauchy stress due to the inhomogeneous director rotation. Based on the principles of objectivity and symmetry, we present the general form of free energy densities and Rayleigh dissipation function and give some possible invariants of constitutive functions. Further, we propose a simple model to study the rate dependence of stretch induced reorientation processes for thin LCE films. Semi-analytical method is utilized to obtain the solutions of constrained uniaxial stretches and stretches with shear for homogenous deformations. The results indicate that the stress-deformation response and the director rotation are rate dependent and can be non-monotonic depending on the initial orientations. Finite element simulations are carried out to study the process of uniaxial stretches with fixed grips. Two different types of stress induced director reorientation processes are observed, one via stripe domains and the other via uniform rotations. We find that the appearance of the stripe domains has a strong dependence on aspect ratios and initial director orientation, which show good agreement with experiment results.
The metal-free graphitic carbon nitride is a promising photocatalyst for peroxymonosulfate (PMS) activation towards water decontamination, but bearing low efficiency due to its electronic structure ...and surface chemistry. Herein, the non-metallic element boron was adopted for catalyst development. The boron dopants and defects were simultaneously introduced by potassium borohydride, resulting in an excellent activity towards PMS activation. The dominant reactive oxygen species was singlet oxygen, which was determined to originate from PMS activation over photo-induced holes initiated by an electron transfer process. Calculations based on density functional theory revealed that at excited states, due to the dopants and defects, the electron-hole distribution was altered from an even population to a significant separation, which was beneficial for photocatalytic performance. Besides, the engineered electronic structure weakened the catalyst resistance to charge transfer, enabling easier electron transfer between the catalyst and the PMS. Moreover, the strengthened and enlarged positive electrostatic potential areas on heptazine rings oriented the electron transfer process from the negatively charged PMS to the catalyst, facilitating the generation of singlet oxygen. These findings provide underlying mechanism insights into the contribution of dopants and defects to catalytic performance on persulfate-based photocatalytic water treatment.
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•Boron dopants and defects were simultaneously introduced into g-CNU.•Singlet oxygen was generated from PMS activation over photo-induced holes.•DFT calculations were performed for catalytic mechanism study.•Boron dopants strengthen the positive electrostatic potential on catalyst surface.•Boron dopants and defects show a synergy on electron-hole separation.
Crawling by means of the traveling deformation of a soft body is a widespread mode of locomotion in nature—animals across scales, from microscopic nematodes to earthworms to gastropods, use it to ...move around challenging terrestrial environments. Snails, in particular, use mucus—a slippery, aqueous secretion—to enhance the interaction between their ventral foot and the contact surface. In this study, a millimeter‐scale soft crawling robot is demonstrated that uses a similar mechanism to move efficiently in a variety of configurations: on horizontal, vertical, as well as upside‐down surfaces; on smooth and rough surfaces; and through obstacles comparable in size to its dimensions. The traveling deformation of the robot soft body is generated via a local light‐induced phase transition in a liquid crystal elastomer and resembles the pedal waves of terrestrial gastropods. This work offers a new approach to micro‐engineering with smart materials as well as a tool to better understand this mode of locomotion in nature.
A millimeter‐scale crawling robot is demonstrated that uses a light‐induced traveling deformation of a soft liquid crystal elastomer body and artificial mucus for adhesive locomotion, similar to that of terrestrial gastropods. This work offers a new approach to soft robotics and micro‐engineering with smart materials as well as a tool to better understand this mode of locomotion in nature.
We herein describe the chiral diboron‐templated asymmetric homocoupling of aryl alkyl ketimines, providing for the first time a series of chiral vicinal tetrasubstituted diamines with excellent ee ...values and good to high yields. The powerful and efficient diboron‐participated 3,3‐sigmatropic rearrangement is successfully demonstrated by the homocoupling of a variety of ketimines thanks to the rational design and engineering of chiral diborons. Systematic DFT studies suggest that two chiral diborons adopt different conformational assembling strategies to couple the diboron template with ketimine substrates in their tight concerted transition states to ensure the excellent enantioselectivities. The synthetic value of chiral vicinal tetrasubstituted diamines is demonstrated by the asymmetric α‐bromination of aliphatic aldehydes by employing a chiral vicinal tetrasubstituted diamine‐based organocatalyst.
A series of chiral vicinal tetrasubstituted diamines are prepared with high ee values and good to excellent yields via an unprecedented chiral diboron‐templated asymmetric homocoupling of aryl alkyl ketimines. The synthetic value of these chiral vicinal tetrasubstituted diamines is demonstrated by the development of efficient organocatalysts for the asymmetric α‐bromination of aliphatic aldehydes.
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•Hollow shell-core Co@NC with exposed two different cobalt species (i.e., Co NPs and Co-Nx site) was prepared by on-step thermal conversion of ZIF-8@ZIF-67 precursor.•Cobalt species ...of Co@NC play a crucial role in the non-radical-dominated PMS activation and TCH degradation.•Co-Nx site could directly adsorb PMS (*PMS) and facilitate PMS decomposition to form 1O2 while Co NPs indirectly accelerate the generation of 1O2via electron transfer.•Good stability and reusability, high environmental robustness and universal adaptability were demonstrated in Co@NC/PMS system.
Cobalt species often play a crucial role in the sulfate radical (SO4−) generation during peroxymonosulfate (PMS) activation, but their roles in the formation of non-radical-dominated PMS activation are largely unclear. Here, shell-core hollow Co@NC with exposed two different cobalt species (i.e., Co nanoparticles and Co-Nx site) was prepared and used to activate PMS for tetracycline hydrochloride (TCH) degradation. The experimental results and theoretical calculations showed cobalt species play a crucial role in the 1O2-dominated TCH degradation in which Co-Nx directly served as active sites to adsorb PMS (*PMS) to facilitate PMS decomposition to form SO5−, and thereafter evolved into 1O2 by the rapid self-reaction of SO5−, while Co nanoparticles indirectly promote 1O2 generation via electron transfer due to their excellent conductivity. With exposed cobalt species and unique structure, Co@NC showed a remarkable catalytic activity for TCH degradation, outperforming the synthesized NC, Co-NC, and commercial Co3O4, Fe3O4 and MnO2. Meanwhile, the good stability and reusability, high environmental robustness and universal adaptability of Co@NC were demonstrated. The TCH degradation pathways including aniline ring oxidation, the cleavage of functional groups and ring-opening reactions were also proposed. The improved understanding on the roles of cobalt species in the non-radical-dominated PMS activation may inspire the development of efficient, selective, and robust cobalt-based catalysts.
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