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排序方式: 共有145条查询结果,搜索用时 46 毫秒
41.
Jemini Jose Athimotlu Raju Rajamani Sreekanth Anandaram Sujin P. Jose Sebastian C. Peter Sreeja P B 《应用有机金属化学》2019,33(9)
Covalently anchored chromium complex on reduced graphene oxide (rGO‐Cr) is successfully synthesised through trimethoxy silyl propanamine (TMSPA) and phenyl azo salicylaldehyde (PAS) coupling. The rGO‐Cr is characterised by Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), electron dispersive analysis of X‐rays (EDAX), Raman spectroscopy, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). Absorption and emission properties of rGO‐TMSPA‐PAS are studied by excitation dependent photoluminescence emissions at room temperature. Electrochemical sensing activity of rGO‐Cr is monitored for paracetamol using modified glassy carbon electrode. Cyclic voltammetry measurements indicated that rGO‐Cr substantially enhance the eletrochemical response of paracetamol. The experimental factors are investigated and optimized. 相似文献
42.
Caussanel F Wang K Ramachandran SA Deslongchamps P 《The Journal of organic chemistry》2006,71(19):7370-7377
Total syntheses of two new (+/-)-kempane derivatives 30 and 47 were achieved with transannular Diels-Alder reaction (TADA) serving as the key step for the stereoselective formation of tricyclic [6.6.5] system 3. This synthetic approach also reveals that the geometry of the C3 group of such a tricyclic system plays an important role for the formation of the seven-membered kempane skeleton. 相似文献
43.
Maire P Königsmann M Sreekanth A Harmer J Schweiger A Grützmacher H 《Journal of the American Chemical Society》2006,128(20):6578-6580
A [16 + 1] valence electron configured rhodium aminyl radical complex could be synthesized and characterized in detail by pulse EPR spectroscopy and DFT calculations. The unpaired electron is delocalized over the metal center and two adjacent nitrogens. H-abstraction reactions from thiols and triethylsilane show that the spin density is predominantly localized on both nitrogens. 相似文献
44.
Sudib K. Mishra P.A. Deymier Krishna Muralidharan G. Frantziskonis Sreekanth Pannala Srdjan Simunovic 《Ultrasonics sonochemistry》2010,17(1):258-265
We introduce a model of cavitation based on the multiphase Lattice Boltzmann method (LBM) that allows for coupling between the hydrodynamics of a collapsing cavity and supported solute chemical species. We demonstrate that this model can also be coupled to deterministic or stochastic chemical reactions. In a two-species model of chemical reactions (with a major and a minor species), the major difference observed between the deterministic and stochastic reactions takes the form of random fluctuations in concentration of the minor species. We demonstrate that advection associated with the hydrodynamics of a collapsing cavity leads to highly inhomogeneous concentration of solutes. In turn these inhomogeneities in concentration may lead to significant increase in concentration-dependent reaction rates and can result in a local enhancement in the production of minor species. 相似文献
45.
A regio- and stereoselective preparation of chiral quaternary 1,2/1,3-diols from acyclic tri-substituted alkenes is disclosed. Optically active tertiary alcohols are the constituents of several bioactive natural products, pharmaceuticals and a general method for their preparation is desirable. A sulfinyl moiety has been utilized as an intramolecular nucleophile. 相似文献
46.
Bushra Y Ahmed Sridhara Chakravarthy Ruben Eggers Wim TJMC Hermens Jing Ying Zhang Simone P Niclou Christiaan Levelt Fred Sablitzky Patrick N Anderson AR Lieberman Joost Verhaagen 《BMC neuroscience》2004,5(1):1-11
Background
As development proceeds the human embryo attains an ever more complex three dimensional (3D) structure. Analyzing the gene expression patterns that underlie these changes and interpreting their significance depends on identifying the anatomical structures to which they map and following these patterns in developing 3D structures over time. The difficulty of this task greatly increases as more gene expression patterns are added, particularly in organs with complex 3D structures such as the brain. Optical Projection Tomography (OPT) is a new technology which has been developed for rapidly generating digital 3D models of intact specimens. We have assessed the resolution of unstained neuronal structures within a Carnegie Stage (CS)17 OPT model and tested its use as a framework onto which anatomical structures can be defined and gene expression data mapped.Results
Resolution of the OPT models was assessed by comparison of digital sections with physical sections stained, either with haematoxylin and eosin (H&E) or by immunocytochemistry for GAP43 or PAX6, to identify specific anatomical features. Despite the 3D models being of unstained tissue, peripheral nervous system structures from the trigeminal ganglion (~300 μm by ~150 μm) to the rootlets of cranial nerve XII (~20 μm in diameter) were clearly identifiable, as were structures in the developing neural tube such as the zona limitans intrathalamica (core is ~30 μm thick). Fourteen anatomical domains have been identified and visualised within the CS17 model. Two 3D gene expression domains, known to be defined by Pax6 expression in the mouse, were clearly visible when PAX6 data from 2D sections were mapped to the CS17 model. The feasibility of applying the OPT technology to all stages from CS12 to CS23, which encompasses the major period of organogenesis for the human developing central nervous system, was successfully demonstrated.Conclusion
In the CS17 model considerable detail is visible within the developing nervous system at a minimum resolution of ~20 μm and 3D anatomical and gene expression domains can be defined and visualised successfully. The OPT models and accompanying technologies for manipulating them provide a powerful approach to visualising and analysing gene expression and morphology during early human brain development. 相似文献47.
A. Sreekanth 《Journal of Molecular Structure》2003,655(1):47-58
Three Zn(II) complexes of di-2-pyridyl ketone thiosemicarbazone, an octahedral Ni(II) complex of 2-acetylpyridine hexamethyleneiminyl-3-thiosemicarbazone, and a V(V) complex of 2-acetylpyridine morpholyl-3-thiosemicarbazone were prepared and characterized. Crystal structure of Ni(II) and V(V) complexes are reported. The ligand in the nickel complex is found to coordinate in the thione form with a pseudo octahedral geometry and the vanadium(V) complex has trigonal bipyramidal geometry. 相似文献
48.
A kinetic method for the determination of 5.0 × 10-3–8.0 × 10-6 M silver ion is based on the catalysis by silver of the reaction between 1,2-diaminoethane and peroxodisulphate, and titration of the residual oxidant. Copper and manganese interfere at 10:1 mole ratios; zinc and iron are tolerated. 相似文献
49.
In this paper, we consider the equation x 2?L n x y+(?1) n y 2 = ±5 r and determine the values of n for which the equation has positive integer solutions x and y. Moreover, we give all positive integer solutions of the equation x 2?L n x y+(?1) n y 2 = ±5 r when the equation has positive integer solutions. 相似文献
50.
Eco‐Efficient Synthesis of New Pyrido [2, 3‐c] Coumarin Scaffolds Under Sonochemical Method
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Praveen Chidurala Venkateshwarlu Jetti Ramakanth Pagadala Jyotsna S. Meshram Sreekanth Jonnalagadda 《Journal of heterocyclic chemistry》2016,53(2):467-472
We have explored a green and simple approach to assembling of pyrido[2,3‐c]coumarin derivatives via one‐pot multi‐component condensation of 4‐hydroxy‐2H‐chromen‐2‐one, benzaldehyde, acetoacetanilide, and ammonium acetate in the absence of catalyst in ethanol under ultrasound irradiation. Compared with thermal method, this methodology has significant advantages, for example, it can be easily operated, it has an easy work‐up and short reaction times, and it produces satisfactory yields. 相似文献