scholarly journals On the Calcium Phosphate Banding in Silicic Acid Gel

1938 ◽  
Vol 13 (7) ◽  
pp. 493-504 ◽  
Author(s):  
Toshizo Isemura
Keyword(s):  
Calcium Phosphate ◽  
Silicic Acid ◽  
Acid Gel

scholarly journals Fine defective structure of silicon carbide powders obtained from different starting materials

2006 ◽  
Vol 38 (2) ◽  
pp. 177-181 ◽  
Author(s):  
T.V. Tomila ◽  
M.V. Vlasova ◽  
M.G. Kakazey ◽  
K.L. Vyshnyakova ◽  
A.V. Ragulya ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Carbon Black ◽  
Silicic Acid ◽  
Lattice Parameter ◽  
Ir Absorption ◽  
Defective Structure ◽  
Hydrated Cellulose ◽  
Sic Particles ◽  
Acid Gel ◽  
Absorption Characteristics

The fine defective structure of silicon carbide powders obtained from silicic acid-saccharose, aerosil-saccharose, aerosil-carbon black, and hydrated cellulose-silicic acid gel systems was investigated. The relation between IR absorption characteristics and the microstructure of SiC particles obtained from different starting materials was established. The numerical relationship between the lattice parameter a and the frequency ?TO is presented.

Viscosity of the Silicic Acid Gel-Forming Mixtures

1932 ◽  
Vol 36 (5) ◽  
pp. 1384-1390 ◽  
Author(s):  
Mata Prasad ◽  
S. M. Mehta ◽  
J. B. Desai
Keyword(s):  
Silicic Acid ◽  
Acid Gel

scholarly journals In Vitro Effects of Silicon on the Action Patterns of Sugarcane Acid Invertase

1969 ◽  
Vol 52 (4) ◽  
pp. 311-322
Author(s):  
Alex G. Alexander
Keyword(s):  
Silicic Acid ◽  
Structural Changes ◽  
Gel Filtration ◽  
Acid Invertase ◽  
Sucrose Hydrolysis ◽  
In Vitro Effects ◽  
Acid Gel ◽  
Living Tissues ◽  
Hydrolysis Of

In vitro studies of invertase action patterns were conducted in the presence of silicon (Si). This element is known to inhibit the enzyme both in living tissues and cell-free preparations. Substrates included sucrose, raffinose, stachyose, and turanose. Sugarcane acid invertase was prepared from lyophilized immature storage tissue and was partially purified by salt fractionation, dialysis, and gel filtration. Enzyme products were studied by paper chromatography. Two products, fructose and glucose, were quickly obtained in large quantity from sucrose. Against raffinose the reaction proceeded more slowly but yielded a total of four products. This suggests a powerful work potential of cane invertase since complete acid hydrolysis of raffinose gives only three products. It is proposed that both 1 —> 6 and 1 —> 2 linkages are broken. Fructose appears by direct hydrolysis of raffinose and by secondary attacks upon the intermediate product sucrose. Use of stachyose as substrate gave additional evidence for hydrolysis of the 1 —> 6 linkage. Three products were obtained in the presence of only one 1 —> 2 fructosidic linkage. Incorporation of Si into invertase digests abruptly terminated the reactions against sucrose, raffinose and stachyose. The effective Si concentration was slightly more than 3 µmoles of Si per milliliter of digest. Significance of the invertase inhibition is mentioned both from the standpoint of increasing sucrose yield and as an analytical indicator of silicic acid content of plant tissues. When the disaccharide turanose was employed as substrate, increasing Si levels gave additional products rather than suspended enyme action. Four products appeared in the presence of 9 µmoles of Si. The substrates sucrose and raffinose yielded masses of variably-staining products at Si levels above 27 µmoles per milliliter. The latter products were of low chromatographic mobility and resembled fragments of hydrolyzed starch. To account for Si action on invertase it is proposed that a silicic acid gel forms around the enzyme in direct proportion to Si concentration. Inhibition of sucrose hydrolysis does not stem from severe protein structural changes. Rather, the hypothetical, gel-encased enzyme might cease to function against one substrate while retaining or increasing its capacity to attack others.

Extinction Coefficients of the Silicic Acid Gel-Forming Mixtures

1932 ◽  
Vol 36 (4) ◽  
pp. 1324-1336 ◽  
Author(s):  
Mata Prasad ◽  
S. M. Mehta ◽  
J. B. Desai
Keyword(s):  
Silicic Acid ◽  
Extinction Coefficients ◽  
Acid Gel

Colloidal Silicic Acid for the Treatment of Psoriatic Skin Lesions, Arthropathy and Onychopathy. A Pilot Study

1997 ◽  
Vol 25 (4) ◽  
pp. 206-209 ◽  
Author(s):  
A Lassus
Keyword(s):  
Silicic Acid ◽  
Skin Irritation ◽  
Skin Lesions ◽  
Treated Group ◽  
Psoriatic Skin ◽  
Double Blind Study ◽  
Double Blind ◽  
Psoriatic Arthropathy ◽  
Plaque Type ◽  
Acid Gel

In a randomized, double-blind study, patients with chronic plaque-type psoriasis were either treated with 30 ml colloidal silicic acid gel, orally, daily, and topically with the same gel ( n = 15), or were treated identically with placebo gel ( n = 15) for 3 months. One stable psoriatic lesion on the knee or elbow was treated topically and followed throughout the study. Five patients in the treated group and seven controls had psoriatic arthropathy and 11 treated patients and 12 controls had psoriatic onychopathy. Three treated patients and six controls withdrew because of skin irritation or lack of efficacy. In the treated group there were clear improvements in scaling, induration and erythema after treatment. The nail changes were cured in five of 10 evaluable patients in the treated group and joint pain was reduced by almost half in the four evaluable patients with arthropathy. There were no such improvements in the placebo group.

The Effect of Silicic Acid on Calcium Phosphate Precipitation

1989 ◽  
Vol 68 (9) ◽  
pp. 1355-1359 ◽  
Author(s):  
J.J.M. Damen ◽  
J.M. Ten Cate
Keyword(s):  
Crystal Growth ◽  
Calcium Phosphate ◽  
Silicic Acid ◽  
Inhibitory Effect ◽  
Polysilicic Acid ◽  
Lag Period ◽  
Additional Support ◽  
Silica Suspensions ◽  
Calcium Phosphate Precipitation

So that a possible involvement in the mineralization of dental plaque could be investigated, the effects of silicic acid on calcium phosphate precipitation were assessed in vitro. By measuring the decrease in Ca2+ concentration (by means of ion-selective electrodes), we determined both spontaneous precipitation and seeded crystal growth from solutions that contained 1 mmol/L calcium, 7.5 mmol/L phosphate, 50 mmol/L Hepes pH 7.2, and various amounts of silicic acid. Polymerized silicic acid, but not its monomer, was found both to cause a 60% reduction in the lag period that precedes spontaneous precipitation and to enhance the growth rate of seeded hydroxyapatite crystals. Silica suspensions showed effects similar to those of polysilicic acid. In all cases, the precipitated material was found to be hydroxyapatite. Whereas seeded brushite crystals grew slowly without silicic acid, hydroxyapatite was the only mineral detected after crystal growth in the presence of silicic acid. Apparently, polysilicic acid acted as a substrate for hydroxyapatite nucleation, inducing secondary nuclei on both hydroxyapatite and brushite crystals. The finding that polysilicic acid could overcome part of the inhibitory effect of a phosphoprotein on calcium phosphate precipitation gave additional support for the idea that polysilicic acid and silica may promote the formation of dental calculus.

Osteoconductive Properties of β-Tricalcium Phosphate Matrix, Polylactic and Polyglycolic Acid Gel, and Calcium Phosphate Cement in Bone Defects

2012 ◽  
Vol 23 (5) ◽  
pp. e430-e433 ◽  
Author(s):  
Eloá R. Luvizuto ◽  
Thallita P. Queiroz ◽  
Rogério Margonar ◽  
Sônia R. Panzarini ◽  
Eduardo Hochuli-Vieira ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Calcium Phosphate Cement ◽  
Tricalcium Phosphate ◽  
Bone Defects ◽  
Polyglycolic Acid ◽  
Acid Gel

The Function of Water Present in Silicic Acid Gel-The Structure of Silicic Acid Gel

1927 ◽  
Vol 31 (8) ◽  
pp. 1230-1236 ◽  
Author(s):  
H. A. Fells ◽  
J. B. Firth
Keyword(s):  
Silicic Acid ◽  
Acid Gel
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