75 research outputs found
Estimation of the solubility parameters of model plant surfaces and agrochemicals: a valuable tool for understanding plant surface interactions
Background
Most aerial plant parts are covered with a hydrophobic lipid-rich cuticle, which is the interface between the plant organs and the surrounding environment. Plant surfaces may have a high degree of hydrophobicity because of the combined effects of surface chemistry and roughness. The physical and chemical complexity of the plant cuticle limits the development of models that explain its internal structure and interactions with surface-applied agrochemicals. In this article we introduce a thermodynamic method for estimating the solubilities of model plant surface constituents and relating them to the effects of agrochemicals.
Results
Following the van Krevelen and Hoftyzer method, we calculated the solubility parameters of three model plant species and eight compounds that differ in hydrophobicity and polarity. In addition, intact tissues were examined by scanning electron microscopy and the surface free energy, polarity, solubility parameter and work of adhesion of each were calculated from contact angle measurements of three liquids with different polarities. By comparing the affinities between plant surface constituents and agrochemicals derived from (a) theoretical calculations and (b) contact angle measurements we were able to distinguish the physical effect of surface roughness from the effect of the chemical nature of the epicuticular waxes. A solubility parameter model for plant surfaces is proposed on the basis of an increasing gradient from the cuticular surface towards the underlying cell wall.
Conclusions
The procedure enabled us to predict the interactions among agrochemicals, plant surfaces, and cuticular and cell wall components, and promises to be a useful tool for improving our understanding of biological surface interactions
Lactose hydrolysis potential and thermal stability of commercial ÎČ-galactosidase in UHT and skimmed milk
The bioindicative potential evaluation of Tabebuia alba (Cham.) Sandwith, Bignoniaceae, in urban atmospheric pollution
Assessment of Skeletal Muscle Contractile Properties by Radial Displacement: The Case for Tensiomyography
Skeletal muscle operates as a near-constant volume system; as such muscle shortening during contraction is transversely linked to radial deformation. Therefore, to assess contractile properties of skeletal muscle, radial displacement can be evoked and measured. Mechanomyography measures muscle radial displacement and during the last 20 years, tensiomyography has become the most commonly used and widely reported technique among the various methodologies of mechanomyography. Tensiomyography has been demonstrated to reliably measure peak radial displacement during evoked muscle twitch, as well as muscle twitch speed. A number of parameters can be extracted from the tensiomyography displacement/time curve and the most commonly used and reliable appear to be peak radial displacement and contraction time. The latter has been described as a valid non-invasive means of characterising skeletal muscle, based on fibre-type composition. Over recent years, applications of tensiomyography measurement within sport and exercise have appeared, with applications relating to injury, recovery and performance. Within the present review, we evaluate the perceived strengths and weaknesses of tensiomyography with regard to its efficacy within applied sports medicine settings. We also highlight future tensiomyography areas that require further investigation. Therefore, the purpose of this review is to critically examine the existing evidence surrounding tensiomyography as a tool within the field of sports medicine
AlteraçÔes morfolĂłgicas e hemodinĂąmica tardias no territĂłrio esplĂȘnico de pacientes com esquitomosse mansĂŽnica hepatoesplĂȘnica pĂłs-anastomose esplenorrenal distal . (Estudo com ultra-som Doppler)
Enhancing energy expenditure and enjoyment of exercise during pregnancy through the addition of brief higher intensity intervals to traditional continuous moderate intensity cycling
Effect of exercise on the maternal outcome in pregnancy of spontaneously hypertensive rats
Methodological basic of programme of water retention increase in mazowieckie voivodship
W referacie przedstawiono podstawy teoretyczne opracowanego w 2007
roku âProgramu maĆej retencji dla WojewĂłdztwa Mazowieckiegoâ. SzczegĂłlnÄ
uwagÄ zwrĂłcono na zastosowanÄ
procedurÄ waloryzacji obszaru wojewĂłdztwa
pod wzglÄdem potrzeb zwiÄkszania retencji oraz zasady etapowania przedsiÄwziÄÄ
inwestycyjnych i prac modernizacyjnych. OmĂłwiono rĂłwnieĆŒ najwaĆŒniejsze zalecenia
realizacyjne dotyczÄ
ce zwiÄkszania retencji w obszarze wojewĂłdztwa.Paper presents theoretical background of âProgramme of water retention
increase in Mazowieckie Voivodshipâ. Special attention was paid on area evaluation
and proposal of investments order. Evaluation of the voivodship area was focused
on classification of regions, where increase of water retention is of high priority,
average priority or Iow priority. Order of investments (construction or
modernization) was based on evaluation results, but included additionally other
factors as water Ä
uality, presence of protected areas, streams continuity maintaining,
etc. Paper includes also guidelines for program implementation
The potential of bio-monitoring of air quality using leaf characteristics of white willow (**Salix alba** L.)
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