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31.
Inside Cover: tert‐Butyl Nitrite Mediated Regiospecific Nitration of (E)‐Azoarenes through Palladium‐Catalyzed Directed CH Activation (Chem. Eur. J. 32/2014)
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33.
Rai S Mukherjee K Mal M Wahile A Saha BP Mukherjee PK 《Journal of separation science》2006,29(15):2292-2295
A sensitive and accurate High-Performance TLC (HPTLC) method has been developed to determine the quantity of 6-gingerol in rhizomes of Zingiber officinale (family: Zingiberaceae), commonly known as ginger. Methanol extracts of rhizomes from three different sources were used for HPTLC, n-hexane, and diethyl ether (40:60 v/v) as the mobile phase. The Rf of 6-gingerol was found to be 0.40. The calibration plot was linear in the range of 250-1200 ng of 6-gingerol and the correlation coefficient of 0.9997 was indicative of good linear dependence of peak area on concentration. The mean quantity of 6-gingerol was found to be 60.44+/-2.53 mg/g of ginger extract. The method permits reliable quantification of 6-gingerol and good resolution and separation of 6-gingerol from other constituents of ginger. To study the accuracy and precision of the method, recovery studies were performed by the method of standard addition. Recovery values from 99.79 to 99.84% showed the excellent reliability and reproducibility of the method. The proposed HPTLC method for quantitative monitoring of 6-gingerol in ginger can be used for routine quality testing of ginger extracts. 相似文献
34.
A single-step melt-quench in situ thermochemical reduction technique has been used to synthesize a new series of Au° nanoparticles embedded antimony glass–ceramic (K2O–B2O3–Sb2O3–ZnO) dichroic nanocomposites. X-ray and selected area electron diffractions manifest growth of Au° nanoparticles along (2 0 0) planes. The particle sizes obtained from X-ray diffraction patterns are found to vary in the range 4–21 nm. Dichroic behavior is attributed to the elliptical shape gold nanoparticles having aspect ratio 1.2, as observed from the transmission electron microscopy (TEM) images. The Au° nanoparticles exhibit surface plasmon resonance band (SPR) around 600 nm, which experiences red-shifts with increasing Au concentration. These nanocomposites when co-doped with Sm2O3 and excited at 949 nm, exhibit 2-fold intensification of 636 nm red emission transition (4G5/2 → 6H9/2) due to SPR induced local field enhancement of Au° nanoparticles and are promising materials for display applications. 相似文献
35.
Biswanath Das Anjoy Majhi Joydeep Banerjee Nikhil Chowdhury 《Journal of molecular catalysis. A, Chemical》2006,260(1-2):32-34
The Baylis–Hillman adducts have efficiently been converted into the corresponding allyl amides in stereoselective manner by heating in acetonitrile under reflux in the presence of Amberlyst-15 as a catalyst. The catalyst works under heterogeneous conditions and can be recycled. 相似文献
36.
Dibyendu Dana Tuhin Das Athena Choi Ashif I. Bhuiyan Tirtha K. Das Tanaji T. Talele Sanjai K. Pathak 《Molecules (Basel, Switzerland)》2022,27(2)
Cell cycle kinases represent an important component of the cell machinery that controls signal transduction involved in cell proliferation, growth, and differentiation. Nek2 is a mitotic Ser/Thr kinase that localizes predominantly to centrosomes and kinetochores and orchestrates centrosome disjunction and faithful chromosomal segregation. Its activity is tightly regulated during the cell cycle with the help of other kinases and phosphatases and via proteasomal degradation. Increased levels of Nek2 kinase can promote centrosome amplification (CA), mitotic defects, chromosome instability (CIN), tumor growth, and cancer metastasis. While it remains a highly attractive target for the development of anti-cancer therapeutics, several new roles of the Nek2 enzyme have recently emerged: these include drug resistance, bone, ciliopathies, immune and kidney diseases, and parasitic diseases such as malaria. Therefore, Nek2 is at the interface of multiple cellular processes and can influence numerous cellular signaling networks. Herein, we provide a critical overview of Nek2 kinase biology and discuss the signaling roles it plays in both normal and diseased human physiology. While the majority of research efforts over the last two decades have focused on the roles of Nek2 kinase in tumor development and cancer metastasis, the signaling mechanisms involving the key players associated with several other notable human diseases are highlighted here. We summarize the efforts made so far to develop Nek2 inhibitory small molecules, illustrate their action modalities, and provide our opinion on the future of Nek2-targeted therapeutics. It is anticipated that the functional inhibition of Nek2 kinase will be a key strategy going forward in drug development, with applications across multiple human diseases. 相似文献
37.
A parting line for a polyhedron is a closed curve on its surface, which identifies the two halves of the polyhedron for which mold-boxes must be made. A parting line is undercut-free if the two halves that it generates do not contain facets that obstruct the de-molding of the polyhedron. Computing an undercut-free parting line that is as “flat” as possible is an important problem in mold design. In this paper, algorithms are presented to compute such a parting line for a convex polyhedron, based on different flatness criteria. 相似文献
38.
Biswanath Das Harish Holla Katta Venkateswarlu Anjoy Majhi 《Tetrahedron letters》2005,46(51):8895-8897
Treatment of Baylis-Hillman adducts with iodosobenzene (PhIO) in the presence of a catalytic amount of KBr in water at room temperature afforded the corresponding acyloxiranes in good yields. 相似文献
39.
[reaction: see text] Treatment of the acetyl derivatives of the Baylis-Hillman adducts 3-hydroxy-2-methylene-alkanoates and 3-hydroxy-2-methylene-alkanenitriles with unactivated alkyl halides in the presence of Zn in saturated aqueous NH(4)Cl solution at room temperature afforded (2E)-2-substituted-alk-2-enoates in the first case and (2Z)-2-substituted-alk-2-enenitriles with high (Z)-selectivity in the second case. 相似文献
40.
Torsional oscillation of rigid disk in infinite transversely isotropic elastic cylinder 总被引:1,自引:1,他引:0
Sakti Pada Barik Mridula Kanoria P. K. Chaudhuri 《应用数学和力学(英文版)》2006,27(7):911-917
In the present analysis torsional oscillation of a rigid disk in an infinite transversely isotropic elastic cylinder is considered. The effects of anisotropy in the stress intensity factor are shown graphically. 相似文献