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991.
Polydatin or 3-O-β-d-resveratrol-glucopyranoside (PD), a stilbenoid component of Polygonum cuspicadum (Polygonaceae), has a variety of biological roles. In traditional Chinese medicine, P. cuspicadum extracts are used for the treatment of infections, inflammation, and cardiovascular disorders. Polydatin possesses a broad range of biological activities including antioxidant, anti-inflammatory, anticancer, and hepatoprotective, neuroprotective, and immunostimulatory effects. Currently, a major proportion of the population is victimized with cervical lung cancer, ovarian cancer and breast cancer. PD has been recognized as a potent anticancer agent. PD could effectively inhibit the migration and proliferation of ovarian cancer cells, as well as the expression of the PI3K protein. The malignancy of lung cancer cells was reduced after PD treatments via targeting caspase 3, arresting cancer cells at the S phase and inhibiting NLRP3 inflammasome by downregulation of the NF-κB pathway. This ceases cell cycle, inhibits VEGF, and counteracts ROS in breast cancer. It also prevents cervical cancer by regulating epithelial-to-mesenchymal transition (EMT), apoptosis, and the C-Myc gene. The objective of this review is thus to unveil the polydatin anticancer potential for the treatment of various tumors, as well as to examine the mechanisms of action of this compound.  相似文献   
992.
This study was designed to assess the susceptibility of various microorganisms and inhibition on heat-induced protein denaturation against diosgenin and santonin, isolated from Polygonatum verticillatum rhizomes. Both diosgenin and santonin showed significant zone of inhibition when studied against various Gram-positive (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus and Staphylococcus epidermidis) and Gram-negative bacteria (Escherichia coli and Salmonella typhi). In antifungal assay, only santonin exhibited profound sensitivity against various fungi (Aspergillus flavus, Aspergillus niger, Trichoderma harzianum and Fusarium oxysporum) used in the test. Both diosgenin and santonin also exhibited marked attenuation on heat-induced protein denaturation in a concentration-dependent manner with EC50 values of 375 and 310 μg/mL, respectively. In conclusion, both the isolated compounds have antimicrobial potential supported by strong inhibition on protein denaturation and thus support the antimicrobial uses of plant in traditional system of treatment.  相似文献   
993.
In this discussion, a new numerical algorithm focused on the Haar wavelet is used to solve linear and nonlinear inverse problems with unknown heat source. The heat source is dependent on time and space variables. These types of inverse problems are ill-posed and are challenging to solve accurately. The linearization technique converted the nonlinear problem into simple nonhomogeneous partial differential equation. In this Haar wavelet collocation method (HWCM), the time part is discretized by using finite difference approximation, and space variables are handled by Haar series approximation. The main contribution of the proposed method is transforming this ill-posed problem into well-conditioned algebraic equation with the help of Haar functions, and hence, there is no need to implement any sort of regularization technique. The results of numerical method are efficient and stable for this ill-posed problems containing different noisy levels. We have utilized the proposed method on several numerical examples and have valuable efficiency and accuracy.  相似文献   
994.
A kinetic formulation is developed to investigate low‐frequency dust ion acoustic waves (DIAWs) and dust acoustic waves (DAWs) as well as numerically for a four‐component, collisionless, unmagnetized dusty plasma, using the linearized Vlasov–Poisson model for species obeying the Maxwellian distribution. In particular, the dynamics of low‐frequency DIAWs is investigated by considering two cases. In the first case, ions and positive dust particles are assumed to be dynamically adiabatic while the negative dust particles are static in the background. In second case, the ions are taken adiabatic, while both positive and negative dust particles are static in the background. For DAWs, the ions are assumed to be isothermal, while both positive and negative dust species are considered adiabatic. Electrons are assumed to be isothermal in all cases. The linear characteristics and Landau damping rates for DIAWs and DAWs are investigated with effects of the dust particle concentrations and different temperature ratios. It is noted that for higher values of positive dust concentration, DIAWs (DAWs) are less (more) damped. It is also observed that the damping rate increases (decreases) as Ti approaches Te for DIAWs (DAWs). It is worth adding here that the theoretical results presented here are supported by numerical analyses and illustrations. The relevance of the study to laboratory and cosmic plasmas is also pointed out.  相似文献   
995.
In this paper, a new type of quaternionic partner curves is defined as generalized quaternionic involute-evolute curves or (0,2)-quaternionic involute– (1,3)-quaternionic evolute curves in the four-dimensional Euclidean space. The relations between the Frenet frames and curvatures of the quaternionic involute-evolute curve couple are introduced. Moreover, the necessary and sufficient conditions for a quaternionic curve to have a generalized involute are obtained.  相似文献   
996.
Journal of Optimization Theory and Applications - We propose an algorithm to generate inner and outer polyhedral approximations to the upper image of a bounded convex vector optimization problem....  相似文献   
997.
ABSTRACT

We present coarse-grained simulations to investigate folding and association of cyclin-dependent kinase 4 (CDK4) with cyclin D3. In our simulations, the Gō-like model and our coarse-grained model are applied to describe intramolecular and intermolecular interaction of protein molecules, respectively. We investigate conformational stability of each state of CDK4 with/without association to cyclin D3 on a single basin potential with reference to each state of CDK4. The results of simulations for the native CDK4 with cyclin D3 are consistent with an experimental observation. The open CDK4 may associate to cyclin D3 on a different interface from cyclin D3-native CDK4 complex structure. If the open CDK4 associates to cyclin D3, the open CDK4 can slightly fold and become smaller, suggesting an unfolded intermediate. After a double-basin potential with reference to the native and open states of CDK4 is given, the open CDK4 associated with cyclin D3 can smoothly shift to the native CDK4. We propose a structure of a potential candidate of an unfolded intermediate during activation of CDK4.  相似文献   
998.
By using internal combinatorial library we were able to identify (4R)-thiazolidines carboxylic acid and its 2-substituted analogs as active inhibitors of urease. Molecular modeling and virtual screening were utilized to find out potential compounds. Computational techniques were employed at database of 90,000 ligands and selected the structure representing the low energy conformations, Grid and FlexX docking algorithms were used and the top binding ligands were synthesized and screened in wet-lab.  相似文献   
999.
In this paper, we suggest and analyze a new two-step predictor–corrector type iterative method for solving nonlinear equations of the type f(x)=0. This new method includes the two-step Newton method as a special case. We show that this new two-step method is a sixth-order convergent method. Several examples are given to illustrate the efficiency of this new method and its comparison with other sixth-order methods. This method can be considered as a significant improvement of the Newton method and its variant forms.  相似文献   
1000.
We study the loading of sodium atoms into a magneto-optical trap from current-controlled sodium metal dispensers. Contrary to what was previously reported [V. Wippel, C. Binder, W. Huber, L. Windholz, M. Allegrini, F. Fuso, E. Arimondo, Eur. Phys. J. D 17 (2001) 285] we demonstrate a significantly higher number of trapped atoms that make Na dispensers a feasible source of atoms for cold-atom studies. The inherent rise in pressure that naturally arises from metal dispensers as they are heated to release atoms is partially controlled by placing the metal dispensers near the pumping port where an ion pump is connected. We also study the effects of placing the sodium dispensers at different distances from the main vacuum chamber where the atoms are trapped and the effectiveness of using a Zeeman slower to cool the atoms as they emerge from the dispensers. We observe trapping of up to 1.9 × 108 atoms, which is significantly higher by almost three orders of magnitude than previously reported experiments.  相似文献   
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