Painlev\'e Analysis, Prelle-Singer Approach, Symmetries and Integrability of Damped H\'enon-Heiles System

We consider a modified damped version of H\'enon-Heiles system and investigate its integrability. By extending the Painlev\'e analysis of ordinary differential equations we find that the modified H\'enon-Heiles system possesses the Painlev\'e property for three distinct parametric restrictions. For each of the identified cases, we construct two independent integrals of motion using the well known Prelle-Singer method. We then derive a set of nontrivial non-point symmetries for each of the identified integrable cases of the modified H\'enon-Heiles system. We infer that the modified H\'enon-Heiles system is integrable for three distinct parametric restrictions. Exact solutions are given explicitly for two integrable cases.Comment: Accepted for publication in Journal of Mathematical Physic

Mechanical and kinetic effects of shortened tropomyosin reconstituted into myofibrils

The effects of tropomyosin on muscle mechanics and kinetics were examined in skeletal myofibrils using a novel method to remove tropomyosin (Tm) and troponin (Tn) and then replace these proteins with altered versions. Extraction employed a low ionic strength rigor solution, followed by sequential reconstitution at physiological ionic strength with Tm then Tn. SDS-PAGE analysis was consistent with full reconstitution, and fluorescence imaging after reconstitution using Oregon-green-labeled Tm indicated the expected localization. Myofibrils remained mechanically viable: maximum isometric forces of myofibrils after sTm/sTn reconstitution (control) were comparable (~84%) to the forces generated by non-reconstituted preparations, and the reconstitution minimally affected the rate of isometric activation (kact), calcium sensitivity (pCa50), and cooperativity (nH). Reconstitutions using various combinations of cardiac and skeletal Tm and Tn indicated that isoforms of both Tm and Tn influence calcium sensitivity of force development in opposite directions, but the isoforms do not otherwise alter cross-bridge kinetics. Myofibrils reconstituted with Δ23Tm, a deletion mutant lacking the second and third of Tm’s seven quasi-repeats, exhibited greatly depressed maximal force, moderately slower kact rates and reduced nH. Δ23Tm similarly decreased the cooperativity of calcium binding to the troponin regulatory sites of isolated thin filaments in solution. The mechanisms behind these effects of Δ23Tm also were investigated using Pi and ADP jumps. Pi and ADP kinetics were indistinguishable in Δ23Tm myofibrils compared to controls. The results suggest that the deleted region of tropomyosin is important for cooperative thin filament activation by calcium

A new facile strategy for higher loading of silver nanoparticles onto silica for efficient catalytic reduction of 4-nitrophenol

The facile route to higher loading of silver nanoparticles onto a silica support is useful for large-scale synthesis of efficient silver supported catalysts.</p

Polyaniline nanoflowers grafted onto nanodiamonds via a soft template-guided secondary nucleation process for high-performance glucose sensing

We demonstrated that the electrochemical glucose biosensor fabricated using glucose oxidase-immobilized polyaniline nanoflower-grafted nanodiamonds exhibits superior performances.</p