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Potential Analyses (potential + analysis)
Selected AbstractsPreparation and cytocompatibility of chitosan-modified polylactideJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Yumei Xiao Abstract Chitosan-modified PLA (CMPLA) was fabricated to improve cytocompatibility of polylactide (PLA). PMAA-grafted PLA (PMAA-PLA) was obtained through ,-methacrylic acid (MAA) grafted polymerization on PLA surface with photooxidization and UV irradiation. Steady PMAA-PLA microparticle suspension with an average size as 172.8 ± 3.6 nm and zeta potential as ,95.0 ± 0.6 mV was prepared through solvent volatilization. By static electricity interaction and other interactions between PMAA-PLA microsparticles and chitosan molecules, CMPLA was obtained. FTIR, XPS, SEM, and zeta potential analyses indicated that CMPLA was modified with chitosan molecules uniformly. Compared with the PLA control, CMPLA adapted to supporting the attachment and proliferation of L929 cells better. The obtained CMPLA was expected to be used as perfect biomaterial for tissue regeneration. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] What do we learn from motor unit action potentials in surface electromyography?MUSCLE AND NERVE, Issue S11 2002Karin Roeleveld PhD Abstract This article gives an overview of what multichannel surface electromyography can teach us about a motor unit. Background information is given about the generation of surface electromyography in general and surface motor unit potentials in particular. Furthermore, we describe how surface motor unit potentials are related to several motor unit characteristics, such as size, location, neuromuscular junction position, fiber length, fiber type, and metabolic fiber properties. In addition, we show how the spatial characteristics of multichannel surface electromyography can be used to obtain single-surface motor unit potentials. The possibilities, challenges, and problems are discussed. Finally, several examples of surface motor unit potential analyses are given. © 2002 Wiley Periodicals, Inc. Muscle Nerve Supplement 11: S92,S97, 2002 [source] The cognitive consequences of emotion regulation: An ERP investigationPSYCHOPHYSIOLOGY, Issue 3 2008C.M. Deveney Abstract Increasing evidence suggests that emotion regulation (ER) strategies modulate encoding of information presented during regulation; however, no studies have assessed the impact of cognitive reappraisal ER strategies on the processing of stimuli presented after the ER period. Participants in the present study regulated emotions to unpleasant pictures and then judged whether a word was negative or neutral. Electromyographic measures (corrugator supercilli) confirmed that individuals increased and decreased negative affect according to ER condition. Event-related potential analyses revealed smallest N400 amplitudes to negative and neutral words presented after decreasing unpleasant emotions and smallest P300 amplitudes to words presented after increasing unpleasant emotions whereas reaction time data failed to show ER modulations. Results are discussed in the context of the developing ER literature, as well as theories of emotional incongruity (N400) and resource allocation (P300). [source] Charge density and electrostatic potential analyses in paracetamolACTA CRYSTALLOGRAPHICA SECTION B, Issue 3 2009Nouzha Bouhmaida The electron density of monoclinic paracetamol was derived from high-resolution X-ray diffraction at 100,K. The Hansen,Coppens multipole model was used to refine the experimental electron density. The topologies of the electron density and the electrostatic potential were carefully analyzed. Numerical and analytical procedures were used to derive the charges integrated over the atomic basins. The highest charge magnitude (,1.2,e) was found for the N atom of the paracetamol molecule, which is in agreement with the observed nucleophilic attack occurring in the biological media. The electric field generated by the paracetamol molecule was used to calculate the atomic charges using the divergence theorem. This was simultaneously applied to estimate the total electrostatic force exerted on each atom of the molecule by using the Maxwell stress tensor. The interaction electrostatic energy of dimers of paracetamol in the crystal lattice was also estimated. [source] Effect of antibody solution conditions on filter performance for virus removal filter PlanovaÔ 20NBIOTECHNOLOGY PROGRESS, Issue 4 2010Tomoko Hongo-Hirasaki Abstract We investigated the effect of antibody solution conditions (ionic strength, pH, IgG concentration, buffer composition, and aggregate level (dimer content)) on filter performance for a virus removal filtration process using the PlanovaÔ 20N, a virus removal filter. Ionic strength and pH affected the filter flux. A consistent high flux was maintained at an ionic strength greater than 10 mM and at pH 4,8 under a typical buffer composition (sodium chloride, citrate, acetate, and phosphate). Optimum IgG concentration was 10,20 mg/mL allowing for high throughput (kg/m2 of IgG). Dimer content negligibly affected the flux level. Under high throughput conditions, virus spiking did not affect flux whereas a parvovirus logarithmic reduction value greater than 5 was maintained. From the results of zeta potential analyses for IgG and the membrane, we considered that electrostatic interactions between antibodies and the membrane affect filter performance (flux level and throughput). These results indicate that the PlanovaÔ 20N filter is applicable for a wide range of solution conditions typically used in antibody processing. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Extended charge delocalization to 4-phenoxy substituent in benzhydryl solvolysis: possible contribution of non-canonical resonance structure in the cationic transition stateJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 1 2002Kwang-Ting Liu Abstract Solvolytic reactivities of 4-nitrobenzhydryl bromides (2b,5b) and chlorides (2c,5c) were studied using single- and dual-parameter Grunwald,Winstein-type correlation analyses with YBnX and YxBnX scales, respectively. Extended charge delocalization over two aryl rings at cationic transition states were found for 3 and 5, but not for 2 or 4. Calculations of the charge distributions in 3c and in the corresponding cation 3a were performed using a Hartree,Fock approximation (RHF/6-31G* basis set) and density functional models (pBP/DN** and other basis sets), respectively, on Mulliken population analysis and on electrostatic potential analysis. The possible contribution of non-canonical resonance structure is discussed. Copyright © 2001 John Wiley & Sons, Ltd. [source] | ||||||||||