Studies of Serpulid Tube Formation

1956 ◽  
Vol s3-97 (39) ◽  
pp. 411-419
Author(s):  
R. H. HEDLEY
Keyword(s):  
Calcium Carbonate ◽  
Epithelial Cells ◽  
Phosphoric Acid ◽  
Organic Material ◽  
Ferric Iron ◽  
Tube Formation ◽  
Low Ph ◽  
Basic Dyes ◽  
Histochemical Tests ◽  
Heparin Preparation

Calcium carbonate, in a finely granular form, is secreted into the fold of the peristomial collar by a pair of tubulo-racemose glands in the peristomium. Most of the organic material of the tube is secreted by the ventro-lateral epithelial cells which surround the main ducts of the calcium-secreting glands. These cells are always filled with a basiphil mucigen which contains some free a-glycol groups. This material retains its affinity for basic dyes and for ferric iron at a low pH. The affinity for iron is retained when the pH is low enough to exclude carboxyl and phosphoric acid groups from the reaction and it is probable that the sulphuric acid groups are responsible. The reactions of this mucigen to histochemical tests together with the similarity in behaviour of a precipitated heparin preparation make it likely that the material is a sulphomucopolysaccharide.

Calcium pyrophosphate powder synthesized from phosphoric acid and calcium carbonate

2020 ◽  
pp. 42-48
Author(s):  
Tatiana Safronova ◽  
◽  
Tatiana Shatalova ◽  
Snezhana Tikhonova ◽  
Yaroslav Filippov ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Phosphoric Acid ◽  
Functional Materials ◽  
Bone Defects ◽  
Thermal Conversion ◽  
Calcium Pyrophosphate ◽  
Molar Ratio

Powders of calcium pyrophosphate Ca2P2O7 in the form of γ- и β-modifications have been produced as a result of thermal conversion of brushite CaHPO4∙2H2O synthesized from phosphoric acid H3PO4 and calcium carbonate CaCO3 at the molar ratio P / Ca = 1.1. The resulting powders can be used for production of various functional materials including biocompatible and bioresorbable ones for the treatment of bone defects.

INFLUENCE OF STICKY RICE AND ANIONIC POLYACRYLAMIDE ON THE CRYSTALLIZATION OF CALCIUM CARBONATE IN CHINESE ORGANIC SANHETU

2015 ◽  
Vol 22 (06) ◽  
pp. 1550073 ◽  
Author(s):  
HUI LIU ◽  
CHANGSHENG PENG ◽  
MIN DAI ◽  
QINGBAO GU ◽  
SHAOXIAN SONG
Keyword(s):  
Reaction Time ◽  
Calcium Carbonate ◽  
Organic Material ◽  
Organic Materials ◽  
Experimental Results ◽  
Additive Concentration ◽  
Reactant Concentration ◽  
Natural Organic Material ◽  
Anionic Polyacrylamide

The crystallization of calcium carbonate ( CaCO 3) in soil controlled by natural organic material was considered a very important reason to enhance the property of ancient Chinese organic Sanhetu (COS), but how the organic material affected the crystallization of CaCO 3 in COS is still unclear. In this paper, a natural organic material (sticky rice, SR) and a synthetic organic material (anionic polyacrylamide, APAM) were selected as additives to investigate their effect on the crystallization of CaCO 3. The experimental results showed that the morphology and size of CaCO 3 crystals could be affected by the concentration of additives and reaction time, while only the size of CaCO 3 crystals could be affected by the concentration of reactant. Although the morphology and size of CaCO 3 crystals varied greatly with the variation of additive concentration, reactant concentration and reaction time, the polymorph of CaCO 3 crystals were always calcite, according to SEM/EDX, XRD and FTIR analyses. This study may help us to better understand the mechanism of the influence of organic materials on CaCO 3 crystallization and properties of COS.

scholarly journals Insufficient Acidification of Autophagosomes Facilitates Group A Streptococcus Survival and Growth in Endothelial Cells

mBio ◽  
2015 ◽  
Vol 6 (5) ◽  
Author(s):  
Shiou-Ling Lu ◽  
Chih-Feng Kuo ◽  
Hao-Wen Chen ◽  
Yi-Shuan Yang ◽  
Ching-Chuan Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Epithelial Cells ◽  
Bacterial Growth ◽  
Group A Streptococcus ◽  
Multiorgan Failure ◽  
Specific Inhibitor ◽  
Low Ph ◽  
Bafilomycin A1 ◽  
Group A

ABSTRACTGroup A streptococcus (GAS) is an important human pathogen, and its invasion via blood vessels is critically important in serious events such as bacteremia or multiorgan failure. Although GAS was identified as an extracellular bacterium, the internalization of GAS into nonphagocytic cells may provide a strategy to escape from immune surveillance and antibiotic killing. However, GAS has also been reported to induce autophagy and is efficiently killed within lysosome-fused autophagosomes in epithelial cells. In this study, we show that GAS can replicate in endothelial cells and that streptolysin O is required for GAS growth. Bacterial replication can be suppressed by altering GAS gene expression in an acidic medium before internalization into endothelial cells. The inhibitory effect on GAS replication can be reversed by treatment with bafilomycin A1, a specific inhibitor of vacuolar-type H+-ATPase. Compared with epithelial cells in which acidification causes autophagy-mediated clearance of GAS, there was a defect in acidification of GAS-containing vesicles in endothelial cells. Consequently, endothelial cells fail to maintain low pH in GAS-containing autophagosomes, thereby permitting GAS replication inside LAMP-1- and LC3-positive vesicles. Furthermore, treatment of epithelial cells with bafilomycin A1 resulted in defective GAS clearance by autophagy, with subsequent bacterial growth intracellularly. Therefore, low pH is a key factor for autophagy-mediated suppression of GAS growth inside epithelial cells, while defective acidification of GAS-containing vesicles results in bacterial growth in endothelial cells.IMPORTANCEPrevious reports showed that GAS can induce autophagy and is efficiently killed within lysosome-fused autophagosomes in epithelial cells. In endothelial cells, in contrast, induction of autophagy is not sufficient for GAS killing. In this study, we provide the first evidence that low pH is required to prevent intracellular growth of GAS in epithelial cells and that this mechanism is defective in endothelial cells. Treatment of GAS with low pH altered GAS growth rate and gene expression of virulence factors and resulted in enhanced susceptibility of GAS to intracellular lysosomal killing. Our findings reveal the existence of different mechanisms of host defense against GAS invasion between epithelial and endothelial cells.

scholarly journals ISOELECTRIC POINTS FOR THE MYCELIUM OF FUNGI

1924 ◽  
Vol 6 (3) ◽  
pp. 259-271 ◽  
Author(s):  
William J. Robbins
Keyword(s):  
Phosphoric Acid ◽  
Sodium Hydroxide ◽  
Isoelectric Point ◽  
Dry Matter ◽  
Colony Growth ◽  
Potato Dextrose Broth ◽  
Rhizopus Nigricans ◽  
Basic Dyes ◽  
Isoelectric Points ◽  
Initial Ph

1. Mycelium of Rhizopus nigricans when stained with certain acid and basic dyes and washed with buffer mixtures of 0.1 M phosphoric acid and sodium hydroxide responded much like an amphoteric colloid with an isoelectric point near pH 5.0. 2. When grown on potato dextrose agar the reaction of which was varied with phosphoric acid the extent of colony growth of Rhizopus nigricans plotted against the initial Sörensen value of the agar produced a double maximum curve with the minimum between the two maxima at initial pH 5.2. 3. When grown in potato dextrose broth the reaction of which was varied with phosphoric acid the dry matter produced by Rhizopus nigricans plotted against the Sörensen value of the broth produced a double maximum curve with the minimum between the two maxima at initial pH 5.2 or average pH 4.9. 4. Mycelium of Rhizopus nigricans placed in buffer mixtures of 0.01 M phosphoric acid and sodium hydroxide of pH 4.1 to 6.3, changed the reaction in most cases toward greater alkalinity. 5. Mycelium of Fusarium lycopersici stained with certain acid and basic dyes and washed with buffer mixtures of 0.1 M phosphoric acid and sodium hydroxide responded much like an amphoteric colloid with an isoelectric point near pH 5.5.

The Loess Modified Methods for Defending Seismic Loading and its Microstructure Analysis

2013 ◽  
Vol 838-841 ◽  
pp. 1600-1608 ◽  
Author(s):  
Jin Deng ◽  
Lan Min Wang ◽  
Jin Jie Sun
Keyword(s):  
Calcium Carbonate ◽  
Phosphoric Acid ◽  
Dynamic Deformation ◽  
Dynamic Strength ◽  
Seismic Loading ◽  
Loading Test ◽  
Talcum Powder ◽  
Filling Materials ◽  
Seismic Deformation ◽  
Barium Metaborate

Loess with large thickness is widely distributed mainly in Gansu provinces of China. The kind of loess has special microstructure to induce lower dynamic strength and larger seismic deformation. It brings to difficult loess processing challenges for engineering building foundations or high way and railway constructions. The large deformation dangers could induce to serious seismic subsidence, watering deformation or loess landslip. There have been series problems of how to change its natural microstructure for engineering demanded which is major concerned in this paper. We put forward Phosphoric modified methods to treat loess problems. By changing different proportions of adding filling materials, such as Calcium carbonate, barite, talcum powder, and others auxiliaries including phosphoric acid and barium metaborate, found it get to be better effect. It’s dynamic deformation coefficients dropped lower than 2‰. After loading test, the methods prove to be greatly enhanced loading strength and changed its unreasonable microstructure. Because of no toxicity materials be adopted and produced during course, the method can be popularized and applied.

Sign in / Sign up

Export Citation Format

Share Document