the paper deals with the analysis of the external factor (solar activity, volcanic eruptions) influence on tree growth at the kola peninsula, northwestern russia. pinus sylvestris l. (scots pine) tree-ring chronologies collected nearby the northern timberline (68.63n, 33.25e) include the oldest (1445-2005 ad) living pine tree found up to date in the kola peninsula. a total of 18 living trees p...

We present a statistical approach to protein structure by introducing a representation of protein folds based on simple observables defined as frequencies of oriented cycles in contact graphs. Motivated by the idea that these cycles may form a code of the entire protein structure we investigate its Shannon entropy. The latter surprisingly shows a characteristic transitory behavior when traced o...

Nature uses air as a carrier gas to desalinate seawater through evaporation and rain. Several investigators have previously studied desalination cycles based on carrier gas processes. However, single pressure carrier gas cycles suffer from low energy recovery and hence low performance. Here we discuss a novel carrier gas cycle which operates under varied pressure. This cycle operates the evapor...

V2O5 xerogel films were fabricated by casting V2O5 sols onto fluorine-doped tin oxide glass substrates at room temperature. Five, ten and twenty atomic layers of Al2O3 were grown onto as-fabricated films respectively. The bare film and Al2O3-deposited films all exhibited hydrous V2O5 phase only. Electrochemical impedance spectroscopy study revealed increased surface charge-transfer resistance o...

The present study investigated the mechanical properties of tendon fascicles from the anterior and posterior human patellar tendon. Collagen fascicles from the anterior and posterior human patellar tendon in healthy young men (mean +/- SD, 29.0 +/- 4.6 yr, n = 6) were tested in a mechanical rig. A stereoscopic microscope equipped with a digital camera recorded elongation. The fascicles were pre...

A nanoscale, visible-light, self-sensing stress probe would be highly desirable in a variety of biological, imaging, and materials engineering applications, especially a device that does not alter the mechanical properties of the material it seeks to probe. Here we present the CdSe-CdS tetrapod quantum dot, incorporated into polymer matrices via electrospinning, as an in situ luminescent stress...

This study deals with the effect of coupled thermal and cyclic mechanical loadings on the viscoelastic response of carbon black filled nitrile rubber. For this purpose, cyclic loading tests were performed at different temperatures by means of Dynamic Mechanical and Thermal Analysis (DMTA). The type and level of the thermomechanical loadings applied were chosen in order to determine the relative...

Constitutive models for soft biological tissues and in particular for human organs are required for medical applications such as surgery simulation, surgery planning, diagnosis. In the literature the mechanical properties of biosolids are generally presented in ”preconditioned” state, i.e. the stabilized conditions reached after several loading-unloading cycles. We hereby present experiments on...

Crouch gait deformity is common in children with cerebral palsy and often is associated with patella alta. Patellar tendon advancement typically is used to correct patella alta and restore normal knee mechanics. The purpose of this study was to determine the mechanical strength of surgical constructs used for fixation during patellar advancement procedures. This study used a cadaveric model to ...

BACKGROUND Repair of composite restorations is a conservative method that can increase the longevity and durability of restorations while preserving the tooth structure. Achieving a suitable bond between the old and new composite is difficult. To overcome this problem, some methods have been recommended to increase the repair bond strength of composite.This study aimed to assess the effect of a...