Adsorption and desorption behaviors of cationic liposome-DNA complexes upon lipofection in inside and outside biomembrane models using a dynamic quasi-elastic laser scattering method.

The dynamic behaviors of cationic liposome-DNA complexes in inside and outside biomembrane models upon lipofection were investigated using the time-resolved quasi-elastic laser scattering (QELS) method. Inside and outside biomembrane models with similar phospholipid compositions to those in living cells were formed at a tetradecane/phosphate buffered saline (TD/PBS) interface. Cationic liposome-DNA complexes were injected into the buffer subphase, and their adsorption/desorption behaviors at the biomembrane models were monitored through changes in the interfacial tension. We found that the adsorption rate of the complexes increased 2.6 times more in the outside model than in the inside one. The adsorption rate of DNA alone did not show a remarkable difference from one side to the other; however, the adsorption rate of the cationic liposome alone showed a similar tendency to that of the liposome-DNA complex. These results indicated that the difference in lipid composition induced a different dynamic behavior of exogenous biomolecules and that the cationic liposomes played an important role in the faster incorporation of DNA into cells upon lipofection.     

Effect of the Fermi motion on nuclear structure functions and the EMC effect

The effect of the Fermi motion on nuclear structure function at largeQ ² (the EMC effect) is discussed in detail. We especially study its dependences on the kinematics of interaction, the 4-momentum transferQ ², the nucleon momentum distribution inside nucleus and the nuclear mass number. Moreover the structure function of¹²C at very largex such asx>1 is evaluated by only the nuclear Fermi motion, and related problems are discussed. We also point out a new dynamical mechanism expected to produce the depletion of valence quark inside nucleus for intermediatex, which does not encroach upon the conventional nuclear physics, and discuss it along the line of scaling hypothesis proposed by Daté et al.     

Asymptotic behavior of solutions of reaction-diffusion equations with varying drift coefficients

The paper concerns the asymptotic behavior as of solutions u(t, x) of the Cauchy problem for the inhomogeneous equation , x>0, with a mass-preserving boundary condition at x=0. It is assumed that F C ¹[0, 1] F(0)=F(1)=0, and that one of the following conditions holds: (i) F has just one zero in (0, 1) and the derivative F is negative at 0 and 1, (ii) F is zero in (0, ) and positive in (, 1) with 0<<1, (iii) F is positive in (0, 1) and c ₀ ² >2F(0) (the pushed case). Here c ₀ is the minimum of possible speeds of travelling waves for the equation with k(x) replaced by zero. Under a natural restriction imposed on k(x) we prove, for a wide class of initial functions, that u(t, x) approaches w(x + m(t)) as uniformly in x>0, where w is a travelling wave with the speed c ₀ and m is a solution of dm/dt = c ₀-k(m). The result has immediate applications to the multidimensional non-linear diffusion equations arising in population genetics, combustion theory, etc.     

A Cell‐Targeted Non‐Cytotoxic Fluorescent Nanogel Thermometer Created with an Imidazolium‐Containing Cationic Radical Initiator

A cationic fluorescent nanogel thermometer based on thermo‐responsive N‐isopropylacrylamide and environment‐sensitive benzothiadiazole was developed with a new azo compound bearing imidazolium rings as the first cationic radical initiator. This cationic fluorescent nanogel thermometer showed an excellent ability to enter live mammalian cells in a short incubation period (10 min), a high sensitivity to temperature variations in live cells (temperature resolution of 0.02–0.84 °C in the range 20–40 °C), and remarkable non‐cytotoxicity, which permitted ordinary cell proliferation and even differentiation of primary cultured cells.     

One‐pot Annulation for Biaryl‐fused Monocarba‐closo‐dodecaborate through Aromatic B−H Bond Disconnection

We have developed a one‐pot annulation reaction of monocarba‐closo‐dodecaborate with cyclic diaryliodonium salts to afford biaryl‐fused derivatives. Aryl functionalities are introduced at both the 1‐carbon and unreactive ortho‐boron vertices of the “σ‐aromatic” carborane cage without the need for pre‐functionalization. DFT calculations revealed that the palladium‐catalyzed C?B bond‐formation step in this process proceeds through a concerted metalation–deprotonation (CMD)‐type pathway for the B?H bond disconnection on the aromatic cage, though such bonds are generally regarded as hydridic.     

Complete thermal-unfolding profiles of oxidized and reduced cytochromes C

The complete thermal-unfolding profiles of both oxidized and reduced forms of cytochrome c551 (PA) from mesophilic Pseudomonas aeruginosa and cytochrome c552 (HT) from thermophilic Hydrogenobacter thermophilus were obtained by the newly developed pressure-proof cell compartment installed in a circular dichroic spectrometer, which facilitates protein thermal-unfolding experiments up to 180 degrees C. The thermodynamic cycle, which relates protein stability and redox function, indicated that the redox potentials of PA and HT in the native state are regulated by the stability of the oxidized proteins rather than by that of the reduced ones.     

Cyclodextrin-modified monolithic columns for resolving dansyl amino acid enantiomers and positional isomers by capillary electrochromatography

We describe beta- and gamma-cyclodextrins (beta- and gamma-CD)-modified monolithic columns prepared by sol-gel process and chemical modifications. The monolithic silica column was fabricated inside a fused-silica capillary with 100 microm inner diameter by sol-gel process. The monolithic silica matrix was chemically modified chiral selectors of beta- or gamma-CDs with a spacer of 3-glycidoxypropyltrimethoxysilane by on-column reactions. Gamma-CD-modified monolithic column has successfully been applied for the separation of dansyl amino acid enantiomers. Beta-CD-modified monolithic column has been used for the separation of the positional isomers of o-, m-, and p-cresols and the enantioseparation of racemates of benzoin and several dansyl amino acids by capillary electrochromatography, respectively. For the separation of neutral positional isomers, a positive electric field was applied. However, for the separation of negatively charged analytes, a negative electric field was applied at the inlet of column. The separation efficiency of 5.0 x 10(4) theoretical plates/m for dansyl-L-threonine was obtained at electric field strength of -300 V/cm in the mobile phase of 50 mM 2-(N-morpholino)ethanesulfonic acid (MES)-Tris/methanol (70/30) buffer at pH 7.0. L-enantiomers were eluted as the first peak. Scanning electron micrograph showed that monolithic columns have the morphology of continuous skeleton and large through-pores.