Eggshell membranes

Choi [59] l-Lactate Dairy products L-Lactate oxidase/with chitosan in an eggshell membrane Oxygen electrode -... 

All animal fibrous proteins tested accumulated gold-cyanide ion from aqueous solution. Adsorption was highest at pH 2 accumulations were up to 9.8% of the DW for wool, 8.6% for eggshell membrane, 7.1% for chicken feathers, and <3.9% for other materials. In the case of eggshell membrane, adsorbed gold was desorbed with 0.1 M NaOH and the material can be used repeatedly. Eggshell membrane could remove gold-cyanide ion at concentrations near 1.0p,g/L. 

PANI/egg shell membrane or PVA Nanotubes Cond. 53 = 9 100 ppm 100 ppm 200 s Electrospun fiber template, eggshell membrane template, chemical polymerization [5]... 

Blood-free tissues could be stored for up to 24 months in 95% ethanol at 4-22 C [3]. Then the tissues should be grounded in a homogenizer, disintegrator or ball mill in order to afford maximum extraction. Different solvents could be used for extraction, including distilled water at different temperatures, salt solutions and aqueous-organic mixtures. Several of the most common methods of the production of hyaluronic acid from the rooster comb are presented in the Table 3.2, although one method describes production from the eggshell membrane. 

Wet eggshell membrane is treated with a yeast enzyme complex to reduce the eggshell membrane particles to a thick, almost clear slurry. The slurry is diafiltered using a 20000 molecular weight cut-off membrane. 

Figure 17.13 Scanning electron micrographs of (a) TiOj-BC hybrid membrane and (b) TiO network templated by BC. (c) Comparison of photocatalytic degradation of rhodamine B by TiO synthesized using BC and eggshell membrane as templates.

After removing the membranes from an eggshell, the shell is dried and its mass recorded as 5.613 g. The eggshell is transferred to a 250-mL beaker and dissolved in 25 mL of 6 M HCl. After filtering, the solution containing the dissolved eggshell is diluted to 250 mL in a volumetric flask. A 10.00-... 

A variety of other calcium transport systems are associated with Ca21-activated ATPases. The extraembryonic structure, the chorioallantoic membrane, of the chick embryo is responsible for the translocation of over 120 mg of eggshell calcium into (he embryo during development. The enzyme responsible for this is a (Ca2+, Mg2+)-ATPase with Km values for Ca2+ of 30 p,mol dm-3 and 0.3 mmol dm-3, and a molecular weight of 170 000. The enzyme can be crossiinked and co-isolated with a calcium-binding protein.158 Transport of Ca2+ is also associated with (Ca2+, Mg2+)-ATPases in neutrophil plasma membranes,159 transverse tubule membranes from rabbit skeletal muscle,160 rabbit myocardial membrane,161 endoplasmic reticulum,162 sar-colemma,163 brain microsomes,164 the Golgi apparatus165 and rat liver plasma membranes.166... 

Sodium, potassium and chloride are the primary dietary ions that influence the electrolytic balance and acid-base status, and the proper dietary balance of sodium, potassium and chloride is necessary for growth, bone development, eggshell quality and AA utilization. Potassium is the third most abundant mineral in the body after calcium and phosphorus, and is the most abundant mineral in muscle tissue. It is involved in electrolyte balance and neuromuscular function. The content of potassium in poultry diets is usually adequate. Chloride is present in gastric juice and chlorine is part of the HC1 molecule which assists in the breakdown of feed in the proventriculus. Sodium is essential for nerve membrane stimulation and ionic transport across cell membranes. Signs of sodium, potassium or chloride deficiency include reduced appetite, poor growth, dehydration and increased mortality. 

Eggshells vary in composition depending on the animal species. Eggs held within the mothers body are surrounded by organic membranes, but those that are deposited outside the body usually have a protective shell. Eggs that are to be externally fertilized or that will be buried are usually soft or pliable. Those laid by animals that will sit on them or stay with them, like most birds, have hard shells. Bird eggshells are mostly calcite (calcium carbonate), mixed with some keratin. 

FIG. 15.1 Electron micrograph of the eggshell of the nematode Haemonchus contortus (from sheep) showing the vitelline (v), chitin (ch) and lipid (1) layers and the embryo bounded by the embryonic membrane (em). 

Two protocols are provided for fixation of Drosophila embryos. Because these embryos are surrounded by both a chorion (eggshell) and an impermeable vitelline membrane, they require special steps to remove these barriers prior to immunostaining or in situ hybridization. Typically, the chorion is dissolved by treatment with sodium hypochlorite (commercial bleach) and the vitelline membrane is removed, either concomitant with or after fixation, by a combination of temperature and osmotic shock. The heptane in these procedures permits the fixative to pass through the vitelline membrane. 

Fig. 2.39 The schematic structure of an egg I eggshell, 2 outer membrane, 3 inner membrane, 4 Chalaza, 5 exterior albumen (outer thin albumen), 6 middle albumen (inner thick albumen), 7 vitelline membrane, 8 nucleus of pander, 9 germinal disk (blastoderm), 10 yellow yolk, 11 white yolk, 12 internal albumen, 13 chalaza, 14 air cell, 15 Cuticle. (Copyright-free Wikipedia picture)...

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