Tissue absorption

Animal tissues, absorption and deposition of conjugated dienoic isomers of linoleic acid, 263-268 Anosmias, flavor chemicals, 19,2U Anticarcinogenic activity, conjugated dienoic derivatives of linoleic acid, 268-269... 

The Premere PFO occluder (Fig. 7) is another selfexpanding double disc device specifically designed for PFO closure. The right-sided anchor is constructed of nitinol between two layers of knitted polyester fabric connected by a flexible polyester braided tether to the left atrial anchor. The left atrial anchor consists of four radiating arms without polyester layers to improve tissue absorption and to minimize thrombus formation. Since the distance between the anchors... 

The aliphatic poly(ether lactonejs are a group of synthetic polymers with high elasticity and high tissue absorptivity [293]. The ether function in the polymer backbone adds flexibility to the ester chain. Ring-opening polymerization of l,4-dioxan-2-one yields an elastic polymer, polydioxanone, with a tensile strength similar to that of human tissue [294]. Polydioxanone has been successfully used to prepare monofilament sutures, with a flexibility superior to that of PGA sutures [294]. Recently, the lipase-catalyzed polymerization of polydioxanone was demonstrated [295]. 

Detection Kr6-1(T9 M Digitized images of tissues. Tissue absorption gives background. Final output 3-dimensional images... 

Chlordecone is readily absorbed (>90%) from the gastrointestinal tract. Absorbed chlordecone rapidly (within 24-48 h) establishes an equilibrium of distribution among most tissues. Absorption of chlordecone may also occur through skin, especially in patients with dermatitis or skin rash. Compared to... 

Totaro et al. published a detailed paper on the factors affecting measurement of cerebrovascular reactivity when measured by NIR [49]. Some of the points covered were the relative transparency of the skin, skull, and brain in the 700- to 1100-nm region and the oxygen-dependent tissue absorption changes of hemoglobin. Their study covered all relevant factors, such as age, sex, reproducibility (often neglected in many academic papers), and venous return. The test was based on a 3-min baseline, a 3-min hypercapnia (5% C02 in air), and a 2-min recovery period. 

OTHER COMMENTS substance is a mixture of alpha isomer (melting point 108-110°C) and beta isomer (melting point 208-210°C) carrier solvents used in commercial formulations may change physical and toxicological properties high toxic organochlorine pesticide that does not accumulate significantly in human tissue absorption is usually increased by alcohols, oil, and emulsifiers. 

The penetration depth depends on the tissue absorption and scattering in a well-determined way. To a first approximation ... 

Figure 15. Diffuse reflectance distributions used to measure tissue absorption and scattering properties non-invasively. (a,b) principle of the technique, showing light entering a point on the tissue surface and the measured radial distribution of the diffusely reflected (backscattered) light that depends on the tissue absorption and scattering properties, (c) external surface probe (courtesy Dr M. Patterson, Hamilton, Canada), (d) endoscopic probe (courtesy Dr R. Bays and colleagues, Lausanne, Switzerland) in this case the distribution is measured along the probe from light input at the end, with the probe placed flat on the tissue (e.g. esophagus) surface.

Thiodicarb was initially lost from skin at a rate similar to that of parathion and carbaryl. After 24 hr, the rate of loss decreased by a factor of 1/6. The initial loss of thiodicarb appears to be due to a combination of events which may include evaporative or other losses, the initial penetration of the dose into skin and rapid distribution to blood and other tissues. Absorption was slow after 24 hr as indicated by the t 1/2 for skin loss of 254 hr. Parathion and carbaryl, on the other hand, penetrated the skin and were absorbed at a more uniform rate after 24 hr according to the skin loss data. The plasma absorption-elimination curve for thiodicarb plateaued after 24 hr. The dose remaining on the surface of the skin acted as an infinite dose supplying the rat with a low but uniform amount of thiodicarb. 

Scattering in Biologic Tissue Absorption in Biologic Tissue... 

As with any modelling process, we have to reach a compromise between a model which accurately describes the phenomena in question, and one which is simple, effective and suited to praetieal needs. If we tried to capture every aspect of the vocal organs directly, we would have to accoimt for every muscle movement, articulator shape and tissue absorption characteristic directly, and then determine how each of these affected how speech production. This would be a huge undertaking, and even if an accurate description of all these factors could be determined, the result may be too complicated for useful analysis. We therefore have to make quite a niunber of simplifying assumptions in order to obtain a usable model. 

Encapsulation (blood non-contacting) —Neointima formation (blood contacting) —Calcification —Tissue Hyperplasia —Tissue absorption... 

Fig. 1 Left. Absorption profiles (logarithmic scale) of water (solid line) and two typical pigments found in biological tissue (dotted line oxyhaemoglobin, dashed line melanin), demonstrating the optical window existing in the near-infrared (NIR). Right Example of NIR transparency in biological tissue. Absorption spectra of the female breast on 44 year (filled squares) and 24 year (open squares) old volunteers. Reproduced from [1] with permission of The Royal Society of Qiemistry for the European Society for Photobiology, the European Photochemistry Association and the RSC...

NIR emission, to minimize the tissue absorption and scattering effects. High stability at physiological pH (6.0-7.4), to maintain chemical stability and photostability and resist non-specific binding to serum proteins. 

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