13 research outputs found
Multiphoton Quantum Optics and Quantum State Engineering
We present a review of theoretical and experimental aspects of multiphoton
quantum optics. Multiphoton processes occur and are important for many aspects
of matter-radiation interactions that include the efficient ionization of atoms
and molecules, and, more generally, atomic transition mechanisms;
system-environment couplings and dissipative quantum dynamics; laser physics,
optical parametric processes, and interferometry. A single review cannot
account for all aspects of such an enormously vast subject. Here we choose to
concentrate our attention on parametric processes in nonlinear media, with
special emphasis on the engineering of nonclassical states of photons and
atoms. We present a detailed analysis of the methods and techniques for the
production of genuinely quantum multiphoton processes in nonlinear media, and
the corresponding models of multiphoton effective interactions. We review
existing proposals for the classification, engineering, and manipulation of
nonclassical states, including Fock states, macroscopic superposition states,
and multiphoton generalized coherent states. We introduce and discuss the
structure of canonical multiphoton quantum optics and the associated one- and
two-mode canonical multiphoton squeezed states. This framework provides a
consistent multiphoton generalization of two-photon quantum optics and a
consistent Hamiltonian description of multiphoton processes associated to
higher-order nonlinearities. Finally, we discuss very recent advances that by
combining linear and nonlinear optical devices allow to realize multiphoton
entangled states of the electromnagnetic field, that are relevant for
applications to efficient quantum computation, quantum teleportation, and
related problems in quantum communication and information.Comment: 198 pages, 36 eps figure
Design, Synthesis, Biological Evaluation, and Molecular Modeling of 2-Difluoromethylbenzimidazole Derivatives as Potential PI3Kα Inhibitors
PI3Kα is one of the potential targets for novel anticancer drugs. In this study, a series of 2-difluoromethylbenzimidazole derivatives were studied based on the combination of molecular modeling techniques 3D-QSAR, molecular docking, and molecular dynamics. The results showed that the best comparative molecular field analysis (CoMFA) model had q2 = 0.797 and r2 = 0.996 and the best comparative molecular similarity indices analysis (CoMSIA) model had q2 = 0.567 and r2 = 0.960. It was indicated that these 3D-QSAR models have good verification and excellent prediction capabilities. The binding mode of the compound 29 and 4YKN was explored using molecular docking and a molecular dynamics simulation. Ultimately, five new PI3Kα inhibitors were designed and screened by these models. Then, two of them (86, 87) were selected to be synthesized and biologically evaluated, with a satisfying result (22.8 nM for 86 and 33.6 nM for 87)
Release Behavior of Folic Acid Grafted Hollow Hydroxyapatite as Drug Carrier
Based on the formation of carbodiimide compounds between carboxyl and primary amines, hollow microspheres arising from the folic acid (folate-FA) grafted onto the surface of the modified hydroxyapatite were successfully prepared. The hollow morphology and composition of the FA-grafted hydroxyapatite microspheres were confirmed by scanning electron microscopy (SEM) and other characterizations. Brunauer-Emmett-Teller (BET) assay revealed the specific surface area and average pore size of the microspheres were 34.58m2/g and 17.80 nm, respectively. As a drug carrier, the kinetic investigation of doxorubicin (DOX) loaded shows that the adsorbed behavior of drug on the adsorbent is more suitable to be described with pseudo-first-order model. Furthermore, the release rate can reach 83% at pH 5.7, which is greater than the release of 39% at pH 7.4, indicating an excellent performance of controlled drug release for response pH. The release mechanism of DOX coincides with Fickian diffusion as a result of Korsmeyer-Peppas model analysis and the release phenomena can be well explained by Fickian diffusion second law
Semipinacol Rearrangement of Iododifluorohomoallyl Alcohols and Its Application in the Allylic CâH Esterification Reactions
We herein present a study on the
Ag(I)-mediated semipinacol
rearrangement
of iododifluorohomoallyl alcohols, the resulting allylic difluoromethyl
ketones underwent oxidative allylic CâH esterification under
palladium catalysis in the absence of external ligand. This process
yielded a range of difluoromethyl ketones derived from allyl esters
in a single operation. The reaction features broad scope of o-nitrobenzoic acids and homoallylic iododifluoroalcohols
affording the targeted molecules in synthetically useful yields. Control
experiments illustrated that the silver salt acted as not only a Lewis
acid to promote the cleavage of a CâI bond and furnish the
semipinacol rearrangement but also a co-oxidant in the catalytic cycle
for the allylic CâH esterification
Discovery of potent and selective urea-based ROCK inhibitors: Exploring the inhibitorâs potency and ROCK2/PKA selectivity by 3D-QSAR, molecular docking and molecular dynamics simulations
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An activity model and a selectivity model from 3D-QSAR studies were established by CoMFA and CoMSIA to explore the SAR. Then docking was used to study the binding modes between ligand and kinases (ROCK2 and PKA), and the molecular docking results were further validated by MD simulations. Computational results suggested that substitution containing positive charge attached to the middle phenyl ring, or electropositive group in urea linker was favored for both activity and ROCK2/PKA selectivity. Finally, three compounds were designed, and biological evaluation demonstrated that these molecular models were effective for guiding the design of potent and selective ROCK inhibitors
A metal-free and recyclable synthesis of benzothiazoles using thiourea as a sulfur surrogate
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Using odorless thiourea as the S source, benzothiazoles and asymmetric disulfides could be obtained from thioformanilides through the tandem cyclization/nucleophilic addition/hydrolysis/nucleophilic substitution reaction. Furthermore, the obtained asymmetric disulfides could readily transfer to benzothiazoles after nitro-reduction and amide formation reaction. This metal-free and recyclable synthetic methodology offered a time-efficient, less expensive, and environmentally friendly alternative to multifunctional benzothiazoles