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Natural Properties (natural + property)

Distribution by Scientific Domains
Humanities and Social Sciences50%

Selected Abstracts

Assessment of bioactive and bio-adhesive therapies to enhance stem cell attachment to root surface dentine

INTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2009
M. A. Elseed
Abstract Aim, To compare bioactive and bio-adhesive therapies to enhance stem cell attachment to the root dentine of human teeth. Methodology, Dentine slabs (n = 72) were cut from the lower 3 mm of the roots of extracted human permanent teeth. The root dentine slabs were untreated, or coated with bio-adhesive, or human recombinant transforming growth factor-beta1 (hrTGF-B1), or human recombinant bone morphogenic protein-2 (hrBMP-2). The dentine slabs were placed with the root surface in contact with confluent periodontal stem cell (PSC) cultures using aseptic techniques. The cells and dentine slabs were submerged in culture media for 4, 24 and 72 h. The specimens were fixed in formalin, dehydrated and processed for scanning electron microscopy (SEM). Results, SEM micrographs at ×2000 magnification revealed PSC extensive adherence to root dentine for all of the bio-adhesive and bioactive treatments. The addition of bioactive molecules did not improve PSC attachment. Few cells attached to the negative control treatments. Conclusions, Bio-adhesive and bioactive growth factors were not needed to promote PSC attachment to the root dentine of human teeth, because it already appears to have good natural properties to promote PSC attachment. This suggests PSC can be used for the clinical replantation of avulsed teeth without the need for bio-adhesive and bioactive treatments. [source]

MORAL PERCEPTION AND THE CAUSAL OBJECTION

RATIO, Issue 3 2010
Justin P. McBrayer
One of the primary motivations behind moral anti-realism is a deep-rooted scepticism about moral knowledge. Moral realists attempt counter this worry by sketching a plausible moral epistemology. One of the most radical proposals in the recent literature is that we know moral facts by perception , we can literally see that an action is wrong, etc. A serious objection to moral perception is the causal objection. It is widely conceded that perception requires a causal connection between the perceived and the perceiver. But, the objection continues, we are not in appropriate causal contact with moral properties. Therefore, we cannot perceive moral properties. This papers demonstrates that the causal objection is unsound whether moral properties turn out to be secondary, natural properties; non-secondary, natural properties; or non-natural properties.1 [source]

THE REGRESS OF PURE POWERS?

THE PHILOSOPHICAL QUARTERLY, Issue 229 2007
Alexander Bird
Dispositional monism is the view that natural properties and relations are ,pure powers'. It is often objected that dispositional monism involves some kind of vicious or otherwise unpalatable regress or circularity. I examine ways of making this objection precise. The most pressing interpretation is that the theory fails to make the identities of powers determinate. I demonstrate that this objection is in error. It does, however, put certain constraints on what the structure of fundamental properties is like. I show what a satisfactory structure would be. [source]

Extraction of Proteins from Biological Fluids by Use of an Ionic Liquid/Aqueous Two-Phase System

CHEMISTRY - A EUROPEAN JOURNAL, Issue 7 2007
Zhuo Du
Abstract An ionic liquid/aqueous two-phase system based on the hydrophilic ionic liquid 1-butyl-3-methylimidazolium chloride (BmimCl) and K2HPO4 has been employed for direct extraction of proteins from human body fluids for the first time. Proteins present at low levels were quantitatively extracted into the BmimCl-rich upper phase with a distribution ratio of about 10 between the upper and lower phase and an enrichment factor of 5. Addition of an appropriate amount of K2HPO4 to the separated upper phase results in a further phase separation, giving rise to an improved enrichment factor of 20. FTIR and UV spectroscopy demonstrated that no chemical (bonding) interactions between the ionic liquid and the protein functional groups were identifiable, while no alterations of the natural properties of the proteins were observed. The partitioning of proteins in the two-phase system was assumed to have been facilitated by the electrostatic potential difference between the coexisting phases, as well as by salting out effects. The system could be applied successfully for the quantification of proteins in human urine after on-line phase separation in a flow system. The use of an ionic liquid, as a green solvent, offers clear advantages over traditional liquid,liquid extractions, in which the use of toxic organic solvents is unavoidable. [source]