501 research outputs found
Effects of Myofascial Release and Dynamic Warm-up on Exercise Performance
Color poster with text, tables, and graphs.The purpose of this study was to compare the use of foam-rolling to dynamic warm-up on flexibility, power, speed, endurance, and balance in young recreationally active adults.University of Wisconsin--Eau Claire Office of Research and Sponsored Programs
A Brief Review of the Genus Polypedilum in Ohio, With Keys to Known Stages of Species Ocurring in Northeastern United States (Diptera, Chironomidae)
Author Institution: Zoology Department, Miami UniversityOf the 25 species recorded for the northeastern states, only four are abundant: Polypedilum scalaenum, with larvae occurring commonly among algae in streams and lotic situations in lakes; P. convictum, highly variable, with larvae occurring widely in rocky streams and in lake localities subject to wave action; P. halterak, sometimes regarded as a nuisance species and a pioneer in silting new reservoirs, present in shallower water of eutrophic lakes and ponds; and P. illinoense, with larvae commonly associated with vegetation {Potamogeton, Nelumbo, Myriophyllum, moss) in relatively quiet and unpolluted water. Less abundant but present in Ohio are the following: P. albicorne, P. tritum, P. sordens, P. fallax, P. calopterus, P. Ontario, P. albinodus, P. acifer, P. trigonus, P. opbioides and P. aviceps. Not yet recorded for Ohio are P. nubeculosum, P. laetum, P. braseniae, P. artifer, P. apicatum, P. parvum, P. gomphus, P. vibex, P. pedatum and P. angustum. Adults of Polypedilum have been collected from May to October in Ohio. Larvae vary from pale yellow to bright red and occupy a wide range of habitats from swift streams to ponds and leaf litter. Generally they form silken tubes in silt or sand or in plant tissues, feeding principally on plankton but larvae are known to occupy cases of caddisworms. Typically late-instar larvae overwinter. Larvae show a wide range of response to organic and industrial pollution. Immatures for 14 of the 25 northeastern species are known
Degradation studies of hydrophilic, partially degradable and bioactive cements (HDBCs) incorporating chemically modified starch
The degradation rate in Hydrophilic, Degradable and Bioactive Cements (HDBCs) containing starch/cellulose acetate blends (SCA) is still low. In order to increase degradation, higher amounts of starch are required to exceed the percolation threshold. In this work, gelatinization, acetylation and methacrylation of corn starch were performed and assessed as candidates to replace SCA in HDBCs. Formulations containing methacrylated starch were prepared with different molar ratios of 2-hydroxyethyl methacrylate and methyl methacrylate in the liquid component and the amount of residual monomer released into water was evaluated. The concentration of reducing sugars, percentage of weight loss and morphologic analyses after degradation all confirmed increased degradation of HDBC with alpha-amylase, with the appearance of pores and voids from enzymatic action. Methacrylated starch therefore is a better alternative to be used as the solid component of HDBC then SCA, since it leads to the formation of cements with a lower release of toxic monomers and more prone to hydrolytic degradation while keeping the other advantages of HDBCs.The authors acknowledge to Foundation for Science and Technology (FCT), who supported this study through funds from project Concept2Cement (POCTI/CTM/60735/2004)
The in vitro bioactivity of two novel hydrophilic, partially degradable bone cements
Composite bone cements were prepared with bioactive glasses (MgO–SiO2–3CaO Æ P2O5) of different reactivities. The matrix of these
so-called hydrophilic, partially degradable and bioactive cements was composed of a starch/cellulose acetate blend and poly(2-hydroxyethyl
methacrylate). The addition of 30 wt.% of glasses to this system made them bioactive in acellular medium: a dense apatite layer
formed on the surface after 7 days of immersion in simulated body fluid. This was demonstrated both by microscopic and infrared spectroscopic
techniques. The composition of the glass and, consequently, its structure was found to have important effects on the rate of the
apatite formation. The combination of reactivity obtained by one formulation with the hydrophilic and degradable character of these
cements makes them a very promising alternative to conventional acrylic bone cements, by allowing a better stabilization of the implant
and a stronger adhesion to the bone
The effect of water uptake on the behaviour of hydrophilic cements in confined environments
Physiological fluids will be in contact with the implant components from the first moments after a surgery. Therefore, the study of the
effect of water on the properties of the bone cements that are part of the arthroplasty procedure is of critical importance to predict the
long-term performance of the whole system. In our research group, we have developed a novel concept, the hydrophilic, partially
degradable and bioactive cements which uptake considerably more water than standard bone cements. In this paper, we aimed to study the
effect of water uptake (WU) by these cements on their behaviour. The tests were carried out in confined cavities, which represent more
accurately the in vivo situation the cement will face (constrained by the bone and prosthesis surfaces). We observed that the equilibrium
WU decreased up to 60% (as compared to non-confined situations), depending of the formulation. This decrease resulted in a latent
tendency of the cements to swell, and the hindering of such swelling generated a swelling pressure against the constraining walls. The
pressure, and consequent press-fitting effect, could be controlled by a number of mechanisms, and resulted in higher stability of the
hydrophilic cements, expressed as an increase in the push-out force, required to extract the specimens from such constrained cavities. This
effect was only observed in hydrophilic cements, not in commercial, hydrophobic ones used as controls. We conclude that such cements
will provide an additional and very useful source of immediate adhesion in the short-term after surgery: water induced press fitting
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