pigment


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pigment

 [pig´ment]
1. any coloring matter of the body.
2. a stain or dyestuff.
3. a paintlike medicinal preparation applied to the skin. adj., adj pig´mentary.
bile pigment any of the coloring matters of the bile, derived from heme, including bilirubin, biliverdin, and several others.
blood pigment (hematogenous pigment) any of the pigments derived from hemoglobin, such as hematoidin, hematoporphyrin, hemofuscin, and methemoglobin.
lipid pigment any of various pigments having lipid characteristics, some of which also contain protein or iron, the most important one being lipofuscin.
respiratory p's substances, e.g., hemoglobin, myoglobin, or cytochromes, which take part in the oxidative processes of the animal body.
retinal p's the photopigments in retinal rods and cones that respond to certain colors of light and initiate the process of vision.

pig·ment

(pig'ment),
1. Any coloring matter, such as that in the red blood cells, hair, or iris, or in the stains used in histologic or bacteriologic work, or that in paint.
2. A medicinal preparation for external use, applied to the skin like paint, or coloring agents used in paints.
[L. pigmentum, paint]

pigment

(pĭg′mənt)
n.
1. A substance used as coloring.
2. A substance, such as chlorophyll or melanin, that produces a characteristic color in plant or animal tissue.
tr.v. pig·mented, pig·menting, pig·ments
To color with pigment.

pig′men·tar′y (pĭg′mən-tĕr′ē) adj.

pigment

Dermatology A substance that imparts color to tissue–eg, skin, eyes, hair. See Accessory pigment, Bile pigment, Malarial pigment, Tattoo, Tyndall.

pig·ment

(pig'mĕnt)
1. Any coloring matter, as, for example, that of the red blood cells, hair, or iris, or the stains used in histologic or bacteriologic work, or that in paints.
2. A medicinal preparation for external use, applied to the skin like paint or coloring agents used in paints.
[L. pigmentum, paint]

pigment 

A coloured substance (e.g. haemoglobin, melanin) found in cells or tissue.
pigment dispersion syndrome See pigment dispersion syndrome.
pigment epithelium See retinal pigment epithelium.
macular pigment A yellow pigment, insensitive to light with a maximum absorption around 460 nm, and located in the inner layers of the macular area of the retina. It extends over an area of about 12º in diameter. Its density declines markedly with eccentricity. The major components of this pigment are the carotenoids: lutein and zeaxanthin. These yellow pigments absorb blue light maximally. The macular pigment has been thought to mitigate the effect of chromatic aberration and to protect the retina against short wavelength radiations. Moreover, lutein and zeaxanthin are antioxidants, which help protect the macula from oxidative stress, and larger plasma concentrations of these pigments may lower the risk of age-related macular degeneration. See red filter; macula lutea; oxidative stress.
visual pigment Photosensitive pigment contained in the outer segments of both rods and cones. The chemical composition of the pigment in both cells is almost the same, there is only a slight difference in the protein opsin. The pigment in the rods is called rhodopsin. The cones contain three other types of pigments (one in each cone), which have spectral absorption curves with a maximum around 420, 530 and 560 nm. These three pigments form the basis of normal trichromatic colour vision. Syn. for cone visual pigments: cyanolabe, chlorolabe and erythrolabe, names sometimes used for the short-wave, middle-wave and long-wave sensitive cone pigments, respectively. Absorption of light by the visual pigments and the subsequent chemical changes that result in photoreceptor potentials represents the first stage in the visual process. Note: erythrolabe, meaning red pigment, has, in fact, its maximum spectral absorption around 560 nm, which is in the green-yellow portion of the visible spectrum. See bleaching; cone cell; rod cell; defective colour vision; retinal densitometry; iodopsin; porphyropsin; rhodopsin; photostress test; trichromatism; Young-Helmholtz theory; transduction.
Table P4 Cone pigments in normal and congenital dichromatic colour vision defects (excluding cases due to anomalies of the central visual pathway)
colour visionlong-wave sensitive (around 560 nm)middle-wave sensitive (around 530 nm)short-wave sensitive (around 420 nm)
normalpresentpresentpresent
protanopeabsent or abnormalpresentpresent
deuteranopepresentabsent or abnormalpresent
tritanopepresentpresentabsent or abnormal

pig·ment

(pig'mĕnt)
1. Any coloring matter, such as that in the red blood cells, hair, or iris, or in the stains used in histologic or bacteriologic work, or that in paint.
2. A medicinal preparation for external use, applied to the skin like paint.
[L. pigmentum, paint]
References in periodicals archive ?
Its main pigment at the show was a high resistant version of diketopyrrolopyrrol (DPP), one of the last major pigments inventions first developed in the early 1970s.
DIC Graphics' Karawang Plant, which is engaged primarily in the production of phthalocyanine blue pigments.
"One of the key factors resulting in the growth of the global pigments market is the increased demand for effect or solar-reflective pigments," says a new report from Techanavio.
Although China is by far the largest producer of synthetic iron oxides, with more than 50 percent of total global supply, the number of production locations for synthetic iron oxide pigments has dropped in half since 2008--particularly affecting red pigment supplies.
Konstanz, Germany, March 18, 2016 --(PR.com)-- The most important sales market for pigments is the production of paints and varnishes which accounts for 45% of total demand.
Lightfastness is determined by the pigment's molecu-lar/crystal structure and particle size.
The other two pigments are the newest additions to the Synergy line of proprietary pigments, which are created by optimizing organic and inorganic pigment chemistries around desired properties and are said to be economical alternatives to more costly pigments in the same color space.
To figure out the purpose of the red pigment, Hoch and his coworkers bred mutant plants that can't make anthocyanins and compared them with plants that do make anthocyanins.
demand for color pigments, including inorganic, organic and specialty types will increase 5.2% to reach $3.4 billion in 2009, according to a new study from the Freedonia Group, Inc.
Some other plant pigments emit fluorescent light in the ultraviolet range.
Also, developments with GCC as a high-brightness rotogravure coating pigment are gaining global acceptance.