Guajamers A-I,Rearranged Polycyclic Phloroglucinol Meroterpenoids from Psidium guajava Leaves and Their Antibacterial Activity

Main observation and conclusion Eight new polycyclic phloroglucinol meroterpenoids guajamers A-H (1-8),a methylated benzoylphloroglucinol meroterpenoid guajamer...     

Base-Promoted Formylation and N-Difluoromethylation of Azaindoles with Ethyl Bromodifluoroacetate as a Carbon Source

Main observation and conclusion We reported for the first time that ethyl bromodifluoroacetate directly reacts with azaindole without transition metal catalysis...     

Thermodynamic Resolution of Pharmaceutical Precursor Modafinil Acid on the Basis of Chiral-at-Metal Strategy

Main observation and conclusion Chiral-at-metal strategy was developed to resolve the essential sulfoxide pharmaceutical intermediates R-modafinil acid and its ...     

Superhydrophobic Flexible Supercapacitors Formed by Integrating Hydrogel with Functional Carbon Nanomaterials

Main observation and conclusion With the rapid development of the wearable electronics,the flexible supercapacitor with high energy density has attracted more a...     

Estimation of biophysical properties of cell exposed to electric field

Excitable media,such as cells,can be polarized and magnetized in the presence of an external electromagnetic field.In fact,distinct geometric deformation can be induced by the external electromagnetic field,and also the capacitance of the membrane of cell can be changed to pump the field energy.Furthermore,the distribution of ion concentration inside and outside the cell can also be greatly adjusted.Based on the theory of bio-electromagnetism,the distribution of field energy and intracellular and extracellular ion concentrations in a single shell cell can be estimated in the case with or without external electric field.Also,the dependence of shape of cell on the applied electronic field is calculated.From the viewpoint of physics,the involvement of external electric field will change the gradient distribution of field energy blocked by the membrane.And the intracellular and extracellular ion concentration show a certain difference in generating timevarying membrane potential in the presence of electric field.When a constant electric field is applied to the cell,distinct geometric deformation is induced,and the cell triggers a transition from prolate to spherical and then to oblate ellipsoid shape.It is found that the critical frequency in the applied electric field for triggering the distinct transition from prolate to oblate ellipsoid shape obtains smaller value when larger dielectric constant of the cell membrane and intracellular medium,and smaller conductivity for the intracellular medium are used.Furthermore,the effect of cell deformation is estimated by analyzing the capacitance per unit area,the density of field energy,and the change of ion concentration on one side of cell membrane.The intensity of external applied electric field is further increased to detect the change of ion concentration.And the biophysical effect in the cell is discussed.So the deformation effect of cells in electric field should be considered when regulating and preventing harm to normal neural activities occurs in a nervous system.     

Theory and phenomenology for a variety of classical and quantum phase transitions

In this review, we first introduce recent progress in the mathematical structure of the three-dimensional Ising model, from the points of view of topologic, algebraic and geometric aspects. Then we discuss in turn Anderson localization due to disorder and then first- and second-order metal-insulator transitions, depending on electron correlation, with and without a magnetic field. Finally, we make intimate contact with the phase diagram showing the equilibrium between low temperature regimes of the magnetically induced Wigner electron solid and the so-called Laughlin electron liquid in the two-dimensional case.     

On the non-symmetric planar aligned NLC cell

The planar aligned nematic liquid crystal cell with different anchoring for the two substrates (i.e. a non-symmetric NLC cell) is investigated by an analytical method. We deduce the basic equations and the boundary conditions of the tilt angle θ of the LC director. Expressions for threshold and saturation magnetic field are obtained, and numerical results of these two quantities with variation in anchoring parameters of the two substrates are given. A symmetry breaking parameter Δ is introduced and the relations between Δ and applied field, as well as the two sets of anchoring parameters are discussed in detail. A feasible experimental plan for measurement of anchoring strengths of a series of different substrates is proposed.     

Effect of graft polymer prepared by living radical polymerisation on electro-optical properties of polymer dispersed liquid crystal

In this study, a graft polymer matrix prepared by living radical polymerisation had been incorporated into polymer dispersed liquid crystals (PDLCs). The electro-optical properties of the PDLCs were investigated. The results showed that the length and density of graft chain had a great influence on the memory effect of the PDLCs. Low-driving-voltage and weak-memory-effect PDLCs could easily be obtained with a graft polymer matrix.     

Preparation of sol–gel materials doped with ionic liquid and extractant for cerium(III) extraction

Silica materials (ILDEHPASGs) consisting of ionic liquids and di-(2-ethylhexyl)phosphoric acid (DEHPA) for Ce(III) extraction was prepared by a sol–gel method using the hydrophobic ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate ([C₈mim]PF₆) as porogen and solvent medium. The ILDEHPASGs were characterized by scanning electron microscopy, Brunauer–Emmett–Teller surface area, Fourier transform infrared, and thermogravimetric analyses. The results indicated the doping of DEHPA and [C₈mim]PF₆ in ILDEHPASG-3 would evidently affect the formation of porous structure of sol–gel materials. ILDEHPASG-3 also possessed more channels and macropores than the blank sorbent; the surface area and pore volume of ILDEHPASG-3 were 409 m² g^?1 and 0.444 cm³ g^?1, respectively. [C₈mim]PF₆ and DEHPA were only physically confined or entrapped in the growing covalent silica network rather than chemically bound to the inorganic matrix. The majority of [C₈mim]PF₆ and DEHPA were stably immobilized in the gel. Then, the effects of contact time and pH were determined. The results showed the sorption of Ce(III) strongly depended on the contact time and pH, and ILDEHPASGs had high sorption ability for Ce(III). The results were analyzed by both Langmuir and Freundlich adsorption isotherm models, and the latter was found to give a better fit.