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31.
Yu Chen Hengchang Guo Wei Gong Luye Qin Hossein Aleyasin Rajiv R Ratan Sunghee Cho Jianxin Chen Shusen Xie 《中国光学快报(英文版)》2013,(1):59-66
In the past two decades, two-photon microscopy (TPM) transforms biomedicalresearch, allowing nondestructive high-resolution fluorescent molecular imaging and label-free imaging in vivo and in real time. Here we review the recent advances of TPM technologyincluding novel laser sources, new image acquisition paradiams, and microendoscopicimaging systems. Then, we survey the capabilities of TPM imagingof biological relevant molecules such as nicotinamideadenine dinucleotide (NADH), flavin adenine dinucleotide (FAD),and reactive oxygen species (ROS). Biomedical applications of TPM in neuroscience and cancer detection are demonstrated. 相似文献
32.
Moumita Majumdar Arup Sinha Tapas Ghatak Sanjib K. Patra Nabanita Sadhukhan S. M. Wahidur Rahaman Jitendra K. Bera Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(8):2574-2585
The complete sequence of reactions in the base‐promoted reduction of [{RuII(CO)3Cl2}2] to [RuI2(CO)4]2+ has been unraveled. Several μ‐OH, μ:κ2‐CO2H‐bridged diruthenium(II) complexes have been synthesized; they are the direct results of the nucleophilic activation of metal‐coordinated carbonyls by hydroxides. The isolated compounds are [Ru2(CO)4(μ:κ2‐C,O‐CO2H)2(μ‐OH)(NPF‐Am)2][PF6] ( 1 ; NPF‐Am=2‐amino‐5,7‐trifluoromethyl‐1,8‐naphthyridine) and [Ru2(CO)4(μ:κ2‐C,O‐CO2H)(μ‐OH)(NP‐Me2)2][BF4]2 ( 2 ), secured by the applications of naphthyridine derivatives. In the absence of any capping ligand, a tetranuclear complex [Ru4(CO)8(H2O)2(μ3‐OH)2(μ:κ2‐C,O‐CO2H)4][CF3SO3]2 ( 3 ) is isolated. The bridging hydroxido ligand in 1 is readily replaced by a π‐donor chlorido ligand, which results in [Ru2(CO)4(μ:κ2‐C,O‐CO2H)2(μ‐Cl)(NP‐PhOMe)2][BF4] ( 4 ). The production of [Ru2(CO)4]2+ has been attributed to the thermally induced decarboxylation of a bis(hydroxycarbonyl)–diruthenium(II) complex to a dihydrido–diruthenium(II) species, followed by dinuclear reductive elimination of molecular hydrogen with the concomitant formation of the RuI? RuI single bond. This work was originally instituted to find a reliable synthetic protocol for the [Ru2(CO)4(CH3CN)6]2+ precursor. It is herein prescribed that at least four equivalents of base, complete removal of chlorido ligands by TlI salts, and heating at reflux in acetonitrile for a period of four hours are the conditions for the optimal conversion. Premature quenching of the reaction resulted in the isolation of a trinuclear RuI2RuII complex [{Ru(NP‐Am)2(CO)}{Ru2(NP‐Am)2(CO)2(μ‐CO)2}(μ3:κ3‐C,O,O′‐CO2)][BF4]2 ( 6 ). These unprecedented diruthenium compounds are the dinuclear congeners of the water–gas shift (WGS) intermediates. The possibility of a dinuclear pathway eliminates the inherent contradiction of pH demands in the WGS catalytic cycle in an alkaline medium. A cooperative binuclear elimination could be a viable route for hydrogen production in WGS chemistry. 相似文献
33.
D. Sadhukhan L. N. Sahoo B. Mondal M. Maiti 《Journal of Applied Mathematics and Computing》2010,34(1-2):1-18
A multispecies harvesting model with mutual interactions is formulated based on Lotka–Voltera model with three competing species which are affected not only by harvesting but also by the presence of prey, predator and the third species, which is super predator. In order to understand the dynamics of the system, it is assumed that the super predator follows the logistic growth. Further, there is demand for all the above three species in the market and hence harvesting of all species is performed. We derive the condition for global stability of the system using a suitable Lyapunov function. The possibility of existence of bioeconomic equilibrium is discussed. The optimal harvest policy is studied and the solution is derived under imprecise inflation in fuzzy environment using Pontryagin’s maximal principle. Finally some numerical examples are discussed to illustrate the model. 相似文献
34.
Noor-ul H. Khan S. Saravanan Rukhsana I. Kureshy Sayed H.R. Abdi Arghya Sadhukhan Hari C. Bajaj 《Journal of organometallic chemistry》2010,695(8):1133-6983
Chiral dimeric vanadium (V) salen complex (10 mol%) derived from 5,5-Methylene di-[(S,S)-{N-(3-tert-butyl salicylidine)-N′-(3′,5′-di-tert-butyl salicylidene)]-1,2-cyclohexanediamine] with vanadyl suphate followed by auto oxidation was used as efficient catalyst for enantioselective Strecker reaction of N-benzylimines with TMSCN at −30 °C. Excellent yield (92%) of α-aminonitrile and high chiral induction was achieved (ee up to 94%) in case of 2-methoxy substituted N-benzylimines in 10 h. The catalytic system worked well up to four cycles with retention of enantioselectivity. 相似文献
35.
Epibatidine (EPB) (1), an alkaloid isolated from the skin of the Ecuadorian poison frog, Epipedobates tricolor has attracted attention because of its exceptionally powerful analgesic properties: several hundred times greater than those of morphine, and the fact that it acts at nicotine rather than opiate receptors. Although the substance is toxic, it does serve as a lead compound in the development of drugs for pain relief as well as treatment of disorders whose pathogenesis involves nicotinic receptors. In this article, isolation, synthetic methods, effect on neuronal and neuromuscular nicotinic receptors, therapeutic potential, toxicity, nicotinic pharmacophore structural modifications related issues of 1 are discussed. 相似文献
36.
Pores and fractures in rocks are continually being reshaped through different chemical and physical processes. Fluids filling the pore space carry the different chemical species responsible for these changes. In the present work we study the relative effects of drift and diffusion of these particles, through a random walk. A bias imposed on the walker determines the competition between drift and diffusion, i.e. to a variation of the Peclet number. We find that the pore structure and hence permeability depends strongly on the bias. 相似文献
37.
This paper describes the method of calculation of the eigenvalues, eigenvectors of the Jacobian matrix of the Euler equations augmented by the convective part of k–ω turbulence model. The equations are 3D and values are expressed in terms of cell normals of a finite volume. The expressions for wave strengths are also found, which are also necessary to calculate the inter‐cell fluxes for Roe's scheme. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
38.
A method is described for determination of minoxidil in human plasma using high-performance liquid chromatography with electrochemical detection. The method is specific and sensitive (500 pg/ml), however, minoxidil and minoxidil sulfate cannot be differentiated due to rapid autohydrolysis of minoxidil sulfate to minoxidil. The extraction procedure employs a C18 preparatory column to remove endogenous plasma constituents which would interfere with the assays. The calibration curves are linear for concentrations from 500 pg to 10 ng/ml. Within-day and between-day reproducibility are satisfactory with coefficient of variation less than 5.7% for all concentrations. Sample recovery from extraction is consistent at 45 to 55% at low and high concentrations, respectively. A pharmacokinetic study in a hypertensive volunteer receiving two different oral doses of minoxidil (1.25 and 2.5 mg) on different occasions demonstrates the utility of the method. 相似文献
39.
Interference and measurement aspects for the double coil resonance experiment are reanalyzed. The resulting situation is analogous
to partial reduction of wave packet in quantum mechanics. Using convergence results of relative frequencies, magnitudes of
the intensity are calculated when prior probabilities are assigned to the coefficients associated with the states. 相似文献
40.
Evidence is presented which demonstrates that 13C-NMR. spectroscopy can be used with confidence in evaluating the configuration of R1R2CHOH centers at C(6) and C(8) of iridoid glucosides. 相似文献