Sponge

O All members of this large group share one common characteristic They do not have a backbone. In the coastal habitats of the intertidal zones, invertebrates such as sponges, corals, anemones, jellyfish, worms, clams, mussels, snails, and limpets make up the majority of the animals. Some are very primitive creatures whose bodies lack the simplest forms of organization. Others are more advanced, with organs and body systems that are highly sophisticated. 

The intertidal zone is a perfect home for many species of invertebrates. Because the area is rich in nutrients, oxygen, and light, it provides plenty of food for small animals who are filter feeders as well as those who are predators. The challenges of these environments require that the invertebrates who reside there be specialized. Pounding waves, periods of little or no water, extreme salinities, and varying temperatures are stressful environmental conditions for all inhabitants. 

Anatomically, sponges are made of only two layers of cells, an outer epidermis and an inner gastrodermis. Sandwiched between these two layers is a jellylike layer, the mesoglea. 

Sponges contain structures that support the cell layers and give the animals shape. In many types of sponges, these structures are small, mineralized needles called spicules that are scattered throughout the mesoglea. Instead of spicules, some species possess fibers made of a tough, rubbery protein called spongin. 

Sponges occur in a variety of forms. In the intertidal zone, their shapes are often dictated by the conditions in which they live. Sponges in high-energy water, where the wave action is strong, may be thin and flat. Those in quieter water may grow into vase or finger shapes. 

The flint boulders embedded at certain levels in chalk strata in England were apparently formed by the gradual syneresis of sponge skeletons. Each skeleton gradually shrank and turned into a rounded boulder. This is a remarkable example of the decrease in surface area even with only a very small decrease in interfacial surface energy over a period of 80 million years. Within the boulders trapped belemnites, oysters, and other debris have been noted by Her. 

The teeth of the limpet P. vulgata were shown to consist of 80 nm fibers rich in SiOs probably bonded together by FejOj (67). In the sea cucumber (Molpadia, intermedia, Holothurioidea) it is interesting that silica occurs in granules in the skin in the form of spheres 100-190 nm in diameter mixed with spherical particles of ferritin of the same size. The latter is a calcium-magnesium-basic iron phosphate (68). The biological role of the silica is unknown, but since the ferritin may serve as 

However, the difficulty of determining whether silica is directly affecting the plant itself or is merely modifying the environment is typified in the investigation by Onodera and Kageshima (76a) of the effect of colloidal silica on rice. The addition of colloidal silica to rice grown in nutrient solution appeared to make the plant more tolerant of potassium. However, it is equally possible that the silica acted as an ion adsorbent and therefore kept the potassium ions out of solution and away from the plants.  

The pollen of certain plants, such as Lychnis alba, has 0.8% silicon (about 2% SiO]) apparently concentrated in the outer structures to ithprove resistance to decay or weathering (76b). 

In many plants soluble silica appears to be taken into the plant merely as an inert component in the water and then deposited wherever it is concentrated as water 

Over 580 million years of evolution has followed the first suggestion of chemical differentiation resulting in an amazing number of biochemical tools for the production of secondary metabolites in marine invertebrates. 

1 Natural History of Sponges—a Primitive Phylum with Remarkable Biosynthetic Capabilities 

Animals of the phylum Porifera, meaning pore bearing, have an amazingly simple yet perfectly functional body plan which consists of collection of cells 

Deuterostomia Phyla Chordata, Echinodermata, Hemichordate, Xenoturbellida 

Current examination of the MarinLit database indicates that 6076 articles have been published with 6980 unique chemical structures from marine sponges.27 This accounts for approximately 22% of the estimated number of species available.27 The number of total structures in this well-known database has now reached over 20000 compounds. Of the marine phyla tested 

BIOINSPIRED AND BIOMIMETIC SYNTHESIS THE USE OF POLY (ALLYLAMEVE HYDROCHLORIDE) 

The growing silica nuclei/particles/sol contain negative charges at neutral pH. It is also known that the silaffins are cationically charged macromolecules, as discussed 

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CqHqIaNOi. Pale, straw-coloured needles, m.p. 198 C. Found in certain marihe organisms, such as corals and sponges, and in the thyroid gland. 

These fascinating bicontinuous or sponge phases have attracted considerable theoretical interest. Percolation theory [112] is an important component of such models as it can be used to describe conductivity and other physical properties of microemulsions. Topological analysis [113] and geometric models [114] are useful, as are thermodynamic analyses [115-118] balancing curvature elasticity and entropy. Similar elastic modulus considerations enter into models of the properties and stability of droplet phases [119-121] and phase behavior of microemulsions in general [97, 122]. 

Texter J, Antalek B and Williams A J 1997 Reverse micelle to sponge phase transition J. Chem. Phys. 106 7869-72... 

There is current interest in hydrogen sponge alloys containing lanthanum. These alloys take up to 400 times their own volume of hydrogen gas, and the process is reversible. Every time they take up the gas, heat energy is released therefore these alloys have possibilities in an energy conservation system. 

Finely divided hafnium is pyrophoric and can ignite spontaneously in air. Care should be taken when machining the metal or when handling hot sponge hafnium. 

Bubbler. I ve done it widening the end of a glass tube, then puting in the hole with pression a piece of glass sponge (for feet) and... 

Isomtriles are stable often naturally occumng compounds that contain a divalent carbon An example is axisonitnle 3 which can be isolated from a species of sponge and possesses anti malanal activity Write a resonance form for axisonitnle 3 that satisfies the octet rule Don t for get to include formal charges... 

I) Dissolve 2.465 g Na3lrCIg in water and dilute to volume. (2) Transfer 1.000 g Ir sponge to a glass tube, add 20 ml of HCI and 1 ml of HCIO4. Seal the tube and place in an oven at 300°C for 24 hr. Cool, break open the tube, transfer the solution to a volumetric flask, and dilute to volume. Observe all safety precautions in opening the glass tube. 

Iron silicate Iron-silicon alloys Iron-silicon-chromium Iron sponge... 

Animal aquaculture is concentrated on finfish, moUuscs, and cmstaceans. Sponges, echinoderms, tunicates, turtles, frogs, and alligators are being cultured, but production is insignificant in comparison with the three principal groups. Common and scientific names of many of the species of the finfish, moUuscs, and cmstaceans currently under culture are presented in Table 2. Included are examples of bait, recreational, and food animals. 

Iron Sponge. An old method for removal of sulfur compounds involves contacting gases containing H2S and H2O with CC- or y-ferric oxide... 

The first cellular synthetic plastic was an unwanted cellular phenol—formaldehyde resin produced by early workers in this field. The elimination of cell formation in these resins, as given by Baekeland in his 1909 heat and pressure patent (2), is generally considered the birth of the plastics industry. The first commercial cellular polymer was sponge mbber, introduced between 1910 and 1920 (3). 

Sintering has been used to produce a porous polytetrafluoroethylene (16). Cellulose sponges are the most familiar cellular polymers produced by the leaching process (123). Sodium sulfate crystals are dispersed in the viscose symp and subsequently leached out. Polyethylene (124) or poly(vinyl chloride) can also be produced in cellular form by the leaching process. The artificial leather-tike materials used for shoe uppers are rendered porous by extraction of salts (125) or by designing the polymers in such a way that they precipitate as a gel with many holes (126). 

Textile uses are a relatively stable area and consist of the lamination of polyester foams to textile products, usually by flame lamination or electronic heat sealing techniques. Flexible or semirigid foams are used in engineered packaging in the form of special slab material. Flexible foams are also used to make filters (reticulated foam), sponges, scmbbers, fabric softener carriers, squeegees, paint appHcators, and directly appHed foam carpet backing. 

Refining. KroU-process hafnium sponge and electrowon hafnium do not meet the performance requirements for the two principal uses of hafnium metal. Eurther purification is accompHshed by the van Arkel-de Boer, ie, iodide bar, process (18) and by electron beam melting. 

Impurities KroU process sponge Electrowon crystals Refined from KroU Electron beam ingot sponge Iodide bar... 

TiH2 is prepared on an industrial scale by dkect combination of hydrogen and the metal (sponge, ingot, scrap, etc) at 200—650°C, followed by cooling in an H2 atmosphere. An alternative method is the reduction of the oxide using calcium hydride under hydrogen ... 

Absorption. Some inks (eg, oil-based newspaper inks) dry by penetration or absorption into the pores of the printed stock, which has a blotter or sponge effect. This is accompHshed by the gross penetration of the ink vehicle into the pores of the substrate, the partial separation of the vehicle from the pigment, and the diffusion of the vehicle throughout the paper. The abiHty of an ink to penetrate into paper depends on the number and size of the air spaces present in the paper, the affinity or receptivity of the stock for the ink, and the mobiHty of the ink. 

Fig. 11. (a) Cross-sectional view of substrate with porous fibers and polyurethane sponge, (b) Cross-sectional view of substrate with bundle of microfibers... 

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