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61.
Leaf extracts of Melicope lunu-ankenda were chemically studied and found to contain mixtures of hydrocarbons and squalene, fatty acids and esters. A geranylated coumaric acid was isolated as the major compound. The crude dichloromethane and methanol extracts of the leaves were found to be strongly larvicidal with LC50 values below 20 microg mL(-1). This is a first isolation of p-O-geranylcoumaric acid from this plant. 相似文献
62.
Epoxidized sunflower oil (ESO) was utilized as a plasticizer for polylactic acid (PLA) using chloroform as a solvent by a solution casting process at various ratios of PLA to ESO. Fourier-transform infrared (FTIR) spectroscopy was used to identify the functional groups of PLA, ESO, and PLA/ESO blends. Thermal stability and mechanical and morphological properties of the blends were investigated by thermogravimetric analysis, tensile property measurements, and scanning electron microscopy technique, respectively. The FTIR spectra indicate that there are some molecular interactions by intermolecular hydrogen bonding between PLA and ESO. PLA/ESO blends show high thermal stability and significant improvement of mechanical properties compared with pure PLA. The highest elongation at break was obtained when the ratio of the PLA/ESO blend was 80/20. Morphological results of PLA/ESO blends show that ESO was well miscible with PLA. 相似文献
63.
We construct quantum games from a table of non-factorizable joint probabilities, coupled with a symmetry constraint, requiring symmetrical payoffs between the players. We give the general result for a Nash equilibrium and payoff relations for a game based on non-factorizable joint probabilities, which embeds the classical game. We study a quantum version of Prisoners' Dilemma, Stag Hunt, and the Chicken game constructed from a given table of non-factorizable joint probabilities to find new outcomes in these games. We show that this approach provides a general framework for both classical and quantum games without recourse to the formalism of quantum mechanics. 相似文献
64.
The conducting polymer electrolyte films consisting of polyacrylonitrile (PAN) as the host polymer, lithium triflate (LiCF3SO3) and sodium triflate (NaCF3SO3) as inorganic salts were prepared by the solution-cast technique. The pure PAN film was prepared as a reference. The ionic
conductivity for the films is characterized using impedance spectroscopy. The room temperature conductivity for the PAN + 26 wt.%
LiCF3SO3 film and the PAN + 24 wt.% NaCF3SO3 film is 3.04 × 10−4 S cm−1 and 7.13 × 10−4 S cm−1, respectively. XRD studies show that the complexation that has occurred in the PAN containing salt films and complexes formed
are amorphous. The FTIR spectra results confirmed the complexation has taken place between the salt and the polymer. These
results correspond with surface morphology images obtained from SEM analysis. The conductivity–temperature dependence of the
highest conducting film from PAN + LiCF3SO3 and PAN + NaCF3SO3 systems follows Arrhenius equation in the temperature range of 303 to 353 K. The PAN containing 24 wt.% LiCF3SO3 film has a higher ionic conductivity and lower activation energy compared to the PAN containing 26 wt.%LiCF3SO3 film. These results can be explained based on the Lewis acidity of the alkali ions, i.e., the interaction between Li+ ion and the nitrogen atom of PAN is stronger than that of Na+ ion. 相似文献
65.
Syed Farooq Adil Mohamed E. Assal Mohammed Rafi Shaik Mufsir Kuniyil Azhar Hashmi Mujeeb Khan Aslam Khan Muhammad Nawaz Tahir Abdulrahman Al-Warthan Mohammed Rafiq H. Siddiqui 《应用有机金属化学》2020,34(8):e5718
Graphene–metal nanocomposites have been found to remarkably enhance the catalytic performance of metal nanoparticle-based catalysts. In continuation of our previous report, in which highly reduced graphene oxide (HRG)-based nanocomposites were synthesized and evaluated, we present nanocomposites of graphene oxide (GRO) and ZnO nanoparticle-doped MnCO3 ([ZnO–MnCO3/(1%)GRO]) synthesized via a facile, straightforward co-precipitation technique. Interestingly, it was noticed that the incorporation of GRO in the catalytic system could noticeably improve the catalytic efficiency compared to a catalyst (ZnO–MnCO3) without GRO, for aerial oxidation of benzyl alcohol (BzOH) employing O2 as a nature-friendly oxidant under base-free conditions. The impacts of various reaction factors were thoroughly explored to optimize reaction conditions using oxidation of BzOH to benzaldehyde (BzH) as a model substrate. The catalysts were characterized using X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, Energy dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET), and Raman spectroscopy. The (1%)ZnO–MnCO3/(1%)GRO exhibited significant specific activity (67 mmol.g−1.hr−1) with full convversion of BzOH and >99% BzH selectivity within just 6 min. The catalytic efficiency of the (1%)ZnO–MnCO3/(1%)GRO nanocomposite was significantly better than the (1%)ZnO–MnCO3/(1%)HRG and (1%)ZnO–MnCO3 catalysts, presumably due to the existence of oxygen-possessing groups on the GRO surface and as well as a very high surface area that could have been instrumental in uniformly dispersing the active sites of the catalyst, i.e., ZnO–MnCO3. Under optimum circumstances, various kinds of alcohols were selectively transformed to respective carbonyls with full convertibility over the (1%)ZnO–MnCO3/(1%)GRO catalyst. Furthermore, the highly effective (1%)ZnO–MnCO3/(1%)GRO catalyst could be successfully reused and recycled over five consecutive runs with a marginal reduction in its performance and selectivity. 相似文献
66.
Muhammad Ajmal Shah Ayesha Hamid Hafiza Ishmal Faheem Azhar Rasul Tourki A. S. Baokbah Muhammad Haris Rimsha Yousaf Uzma Saleem Shabnoor Iqbal Maria Silvana Alves Zahid Khan Ghulam Hussain Ifat Alsharfi Haroon Khan Philippe Jeandet 《Molecules (Basel, Switzerland)》2022,27(21)
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
67.
For any square-free positive integer m, let H(m) be the class-number of the field , where ζm is a primitive m-th root of unity. We show that if m = {3(8 g + 5)}2 ? 2 is a square-free integer, where g is a positive integer, then H(4 m) > 1. Similar result holds for a square-free integer m = {3(8 g +7)}2 ?2, where g is a positive integer. We also show that n|H(4 m) for certain positive integers m and n. 相似文献
68.
Azhar Mahmood Itrat Fatima Shaheen Kosar Rehana Ahmed Abdul Malik 《Magnetic resonance in chemistry : MRC》2010,48(2):151-154
Prunusins A (1) and B (2), the new C‐alkylated flavonoids, have been isolated from the seed kernels of Prunus domestica. Their structures were assigned from 1H and 13C nuclear magnetic resonating spectra, DEPT and by correlation spectroscopy, HMQC and HMBC experiments. 3, 5, 7, 4′‐Tetrahydroxyflavone (3) and 3, 5, 7‐trihydroxy‐8, 4′‐dimethoxyflavone (4) have also been reported from this species. Both compounds (1) and (2) showed significant antifungal activity against pathogenic fungus Trichophyton simmi. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
69.
The rate of formation and disappearance of phthalic anhydride (PAn) intermediate in the aqueous cleavage of N-methoxyphthalamic acid (NMPA) under acidic pH was studied spectrophotometrically in mixed CH3CN-H2O solvents. The rate of formation of PAn from NMPA is almost independent of the change in acetonitrile content from 20 to 70% v/v in mixed aqueous solvents. The rate constants for the formation of PAn from NMPA are approximately 10-fold smaller than the corresponding rate constants for the formation of PAn from o-carboxybenzohydroxamic acid (OCBA). These observations are ascribed to the consequence of the occurrence of slightly different mechanisms in these reactions. 相似文献
70.
Recent developments in the transformation of biobased 5-hydroxymethylfurfural (HMF) into a potential liquid fuel, 2,5-dimethylfuran (DMF), are summarised. This review focuses briefly on the history of HMF conversion to DMF in terms of the feedstock used and emphasises the ideal requirements in terms of the catalytic properties needed in HMF transformation into DMF. The recent state of the art and works on HMF transformation into DMF are discussed in comparison to noble metals and non-noble metals as well as bimetallic catalysts. The effect of the support used and the reaction conditions are also discussed. The recommendations for future work and challenges faced are specified. 相似文献