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The effect of replacing the conventional uniform macroion surface charge density with discrete macroion charge distributions on structural properties of aqueous solutions of like-charged macroions has been investigated by Monte Carlo simulations. Two discrete charge distributions have been considered: point charges localized on the macroion surface and finite-sized charges protruding into the solu

AIM: To study the interactions between human gastric carcinoma cell (HGCC) and human vascular endothelial cell (HVEC), and if the expression of sphingosine kinase (SPK) gene was involved in these interactions. METHODS: The specific inhibitor to SPK, dimethyl sphingosine (DMS), was added acting on HGCC and HVEC, then the cell proliferation was measured by MTT. The conditioned mediums (CMs) of HGCC

Rheumatoid arthritis (RA) is associated with certain MHC class II alleles and is characterized by a chronic autoimmune response in the joints. Using transgenic mice expressing human DR4 (DRB1*0401) and human CD4, but lacking endogenous MHC class II, we show that posttranslational glycosylation of type II collagen (CII) influences the level of T cell tolerance to this candidate cartilage-specific a

Three models are used to study the effect of many-body polarization in the solvation of non-dipolar molecules and ions in water. Two of the models are very simplified and are used to show a number of basic principles of correlation of solvent degrees of freedom and asymmetric solvent structures. These principles are used to interpret results from the third model: an accurate simulation of para-ben

To evaluate the importance of tree leafing for the start of laying and clutch size of birds, we compared the breeding phenology of great tits Parus major and blue tits P. caeruleus between one coastal and two inland sites in the same geographical region. Because of the cooling influence of the sea, trees at the coastal site were known to initiate budburst about a week later than at the inland site

A modification of the constrained geometry optimization method by Anglada and Bofill (Anglada, J. M.; Bofill, J. M. J. Comput. Chem. 1997, 18, 992-1003) is designed and implemented. The changes include the choice of projection, quasi-line-search, and the use of a Rational Function optimization approach rather than a reduced-restricted-quasi-Newton-Raphson method in the optimization step. Furthermo

The laterally and mutually constrained inversion (LCI and MCI) techniques allow for the combined inversion of multiple geophysical datasets and provide a sensitivity analysis of all model parameters. The LCI and MCI work with few-layered models, and are restricted to quasi-layered geological environments. LCI is used successfully for inversion of surface wave (SW) seismic data and MCI for combined

Various transport phenomena occurring in an anode duct of medium temperature solid oxide fuel cell (SOFC) have been simulated and analyzed by a fully three-dimensional calculation method. The considered composite duct consists of a thick porous layer, the gas flow duct and solid current interconnector. Unique fuel cell boundary and interfacial conditions, such as the combined thermal boundary cond

We present QSim, a program for simulation of NMR experiments. Pulse sequences are implemented and analyzed in QSim using a mouse driven interface. QSim can handle almost any modern NMR experiment, using multiple channels, shaped pulses, mixing, decoupling, phase-cycling and pulsed field gradients. Any number of spins with any spin quantum number can, in theory, be used in simulations. Relaxation i

Functions of biologically active molecules are frequently initiated by elementary chemical reactions such as energy and electron transfer, cis-trans isomerizations, and proton transfer. The nature of these reactions generally makes them very fast and efficient, occurring on picosecond and femtosecond timescales. Ultrafast spectroscopy has played an important role in the study of a number of biolog