scholarly journals The Size Stability of Alginate Beads by Different Ionic Crosslinkers

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Shu-Ling Huang ◽  
Yung-Sheng Lin
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
Alginate Bead ◽  
Alginate Beads ◽  
Size Reduction ◽  
Ionic Gelation ◽  
Gelation Process ◽  
Size Stability ◽  
The Stability ◽  
Gelling Time

Few studies have discussed the stability of gelled alginate bead size. Therefore, the present study investigated the dynamic shrinkage of gelled alginate beads affected by two common ionic crosslinkers at different concentrations and temperatures. The results indicate that the gelled alginate beads gradually shrank with longer gelling times. The beads incubated in a Ca2+ solution shrank more dramatically than those incubated in a Ba2+ solution. Those incubated at room temperature exhibited greater shrinkage than those incubated at a low temperature. A 25% size reduction occurred in the 1% Ca2+ solution at room temperature after 300 minutes of gelling time. The alginate beads gelled took at least 120 minutes to become stable after the ionic gelation process.

scholarly journals Investigation of the Influence of Calcium Salts and Gelling Time on the Structural Mechanical Properties of Fruit Jam

2020 ◽  
Vol 77 (2) ◽  
pp. 88
Author(s):  
Zdravko MANEV ◽  
Nadezhda PETKOVA
Keyword(s):  
Calcium Ion ◽  
Alginate Beads ◽  
Rupture Force ◽  
Practical Application ◽  
Bioactive Substances ◽  
Calcium Salts ◽  
Alginate Concentration ◽  
Different Types ◽  
The Stability ◽  
Gelling Time

Alginate beads attract attention as a encapsulation matrix of bioactive substances in food. However, the stability of beads depends on calcium ion and sodium alginate concentration, gelling time and others factors. The aim of this study is to investigate the influence of different types of calcium salts on the structural and mechanical parameters - the rupture force and rupture deformation at different gelling times of the pear jam prepared with soluble dietary fibers and inulin. The relationships between the rupture force and rupture deformation of the fruit jams were established. By increasing the gelling time from 24 hours to 48 hours, the rupture deformation of jams with 7% calcium lactate were reduced and in those with 7% CaCl2 the rupture forces increases. Any change in rupture force was observed for the jam with 3.5% CaCl2. This study demonstrated the practical application of different calcium salts for preparation of stable pear jam.

Stability and Relaxation of Point Defects in amorphous silicon

1992 ◽  
Vol 279 ◽  
Author(s):  
Raymond Lutz ◽  
Laurent J. Lewis
Keyword(s):  
Molecular Dynamics ◽  
Low Temperature ◽  
Amorphous Silicon ◽  
Point Defects ◽  
Room Temperature ◽  
Empirical Potential ◽  
The Stability

ABSTRACTWe have used molecular-dynamics to investigate the stability and relaxation of point defects — vacancies and interstitials — in a model of amorphous silicon, with the interactions between atoms described by the Stillinger-Weber empirical potential. The annihila-tion of point defects has been proposed as an important mechanism by which relaxation proceeds in amorphous silicon. Starting with a Wooten-Winer-Weaire model of a-Si, we “manually” create vacancies in the structure by removing a number of randomly-selected four-fold coordinated atoms. The system is then allowed to relax. Our calculations reveal unambiguously that, of a number of vacancies introduced in the model at low temperature, roughly a third are stable; these anneal out upon heating at room temperature. The vacancies seem, in most cases, to consist of a relatively large empty volume bounded by four atoms of which at least one is undercoordinated. Our study of interstitials seems to indicate that they diffuse through a “jump-and-bump” process, eventually annihilating when a large enough, properly coordinated, vacant volume is encountered.

Effect of pH Value of the Broth on the Gelled Microspheres Containing Zirconium Prepared by Internal Gelation Process

2014 ◽  
Vol 602-603 ◽  
pp. 155-158 ◽  
Author(s):  
Yong Gao ◽  
Jing Tao Ma ◽  
Xing Yu Zhao ◽  
Shao Chang Hao ◽  
Chang Sheng Deng
Keyword(s):  
Room Temperature ◽  
Ph Value ◽  
Internal Gelation ◽  
Uniform Size ◽  
Effect Of Ph ◽  
Gelation Process ◽  
The Stability

The internal gelation process was used to produce gel microspheres containing Zr. The effect of the broth composition particularly pH value on the stability of the broth and morphology of the dried spheres was investigated. The results indicated that the stability of the broth at room temperature increased with the decrease of the pH of the broth. When the pH of the broth was in the range of 1 to 2 the spheres obtained had good sphericity and uniform size and at pH of 1.35 the spheres were transparent.

THE STABILITY OF ENDOGENOUS AND EXOGENOUS CORTICOTROPHIN IN RAT PLASMA AS ESTABLISHED BY A BIOASSAY IN INTACT RATS

1968 ◽  
Vol 41 (4) ◽  
pp. 491-497 ◽  
Author(s):  
H. D. PURVES ◽  
NANCY E. SIRETT
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
Rat Plasma ◽  
Significant Loss ◽  
Working Standard ◽  
The Stability ◽  
Saline Medium ◽  
Intact Rats

SUMMARY Corticotrophin (ACTH) activity in rat plasma, both endogenous (adrenalectomized rat plasma) and exogenous (International Working Standard, 1962), has been assayed in dexamethasone-treated rats and the stability studied under various conditions of storage. Exogenous ACTH added to rat plasma and assayed immediately had only 76% of the activity of the same ACTH dissolved in gelatine acid saline medium. This difference is ascribed to the effects of the medium and not to inactivation. When allowance was made for the effects of the medium on potency, added ACTH showed a similar stability on incubation or storage to endogenous ACTH. For endogenous ACTH the following loss of activity was found in vitro: after 45 min. at 37°, 64%; after 1 day at room temperature, more than 85%; after 1 day at 3°, 58%. No loss of potency was detected on storage at −17° for 18 months. It is concluded that plasma can be frozen, stored at low temperature, and thawed without significant loss of corticotrophic potency provided that the blood is chilled as soon as drawn and the subsequent operations performed expeditiously.

Methods for the Concentration of Bovine Ac-Globulin (Factor V)

1961 ◽  
Vol 06 (03) ◽  
pp. 435-444 ◽  
Author(s):  
Ricardo H. Landaburu ◽  
Walter H. Seegers
Keyword(s):  
Room Temperature ◽  
Barium Carbonate ◽  
Deae Cellulose ◽  
Reducing Agents ◽  
Factor V ◽  
Isoelectric Precipitation ◽  
Stabilizing Agent ◽  
Bovine Plasma ◽  
The Stability

SummaryAn attempt was made to obtain Ac-globulin from bovine plasma. The concentrates contain mostly protein, and phosphorus is also present. The stability characteristics vary from one preparation to another, but in general there was no loss before 1 month in a deep freeze or before 1 week in an icebox, or before 5 hours at room temperature. Reducing agents destroy the activity rapidly. S-acetylmercaptosuccinic anhydride is an effective stabilizing agent. Greatest stability was at pH 6.0.In the purification bovine plasma is adsorbed with barium carbonate and diluted 6-fold with water. Protein is removed at pH 6.0 and the Ac-globulin is precipitated at pH 5.0. Rivanol and alcohol fractionation is followed by chromatography on Amberlite IRC-50 or DEAE-cellulose. The final product is obtained by isoelectric precipitation.

Survival of mouse blastocysts after low-temperature preservation under high pressure

2004 ◽  
Vol 52 (4) ◽  
pp. 479-487 ◽  
Author(s):  
Cs. Pribenszky ◽  
M. Molnár ◽  
S. Cseh ◽  
L. Solti
Keyword(s):  
Phase Transition ◽  
Hydrostatic Pressure ◽  
Low Temperature ◽  
High Hydrostatic Pressure ◽  
Room Temperature ◽  
Freezing Point ◽  
Significant Loss ◽  
Embryo Cryopreservation ◽  
Subzero Temperatures ◽  
Survival Capacity

Cryoinjuries are almost inevitable during the freezing of embryos. The present study examines the possibility of using high hydrostatic pressure to reduce substantially the freezing point of the embryo-holding solution, in order to preserve embryos at subzero temperatures, thus avoiding all the disadvantages of freezing. The pressure of 210 MPa lowers the phase transition temperature of water to -21°C. According to the results of this study, embryos can survive in high hydrostatic pressure environment at room temperature; the time embryos spend under pressure without significant loss in their survival could be lengthened by gradual decompression. Pressurisation at 0°C significantly reduced the survival capacity of the embryos; gradual decompression had no beneficial effect on survival at that stage. Based on the findings, the use of the phenomena is not applicable in this form, since pressure and low temperature together proved to be lethal to the embryos in these experiments. The application of hydrostatic pressure in embryo cryopreservation requires more detailed research, although the experience gained in this study can be applied usefully in different circumstances.

Tyrosine-Selective Bioconjugation with Iminoxyl Radicals

2020 ◽  
Author(s):  
Katsuya Maruyama ◽  
Takashi Ishiyama ◽  
Yohei Seki ◽  
Kounosuke Oisaki ◽  
Motomu Kanai
Keyword(s):  
Reaction Time ◽  
Steric Hindrance ◽  
Room Temperature ◽  
Water Soluble ◽  
Light Irradiation ◽  
Sodium Ascorbate ◽  
Iminoxyl Radical ◽  
Short Reaction Time ◽  
Modified Peptides ◽  
The Stability

A novel Tyr-selective protein bioconjugation using the water-soluble persistent iminoxyl radical is described. The conjugation proceeded with high Tyr-selectivity and short reaction time under biocompatible conditions (room temperature in buffered media under air). The stability of the conjugates was tunable depending on the steric hindrance of iminoxyl. The presence of sodium ascorbate and/or light irradiation promoted traceless deconjugation, restoring the native Tyr structure. The method is applied to the synthesis of a protein-dye conjugate and further derivatization to azobenzene-modified peptides.

Circular dichroism and infrared study of β-turn formation in repeat peptides of elastin

1987 ◽  
Vol 52 (5) ◽  
pp. 1356-1361
Author(s):  
S. Abdel Rahman ◽  
M. Elsafty ◽  
A. Hattaba
Keyword(s):  
Circular Dichroism ◽  
Solid State ◽  
Ir Spectra ◽  
Chain Length ◽  
Room Temperature ◽  
Infrared Study ◽  
Feature Characteristic ◽  
C 50 ◽  
The Stability ◽  
Circular Dichroïsm

The conformation of elastin-like peptides Boc-Ala-Pro-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM were examined in solution using circular dichroism at 30 °C, 50 °C, and 70 °C and in solid state by IR at room temperature. The studies show that the β-turn is a significant conformational feature for peptides under investigation in solution at 30 °C and 50 °C, but at 70 °C the tetra, hexa, and decapeptides show the CD feature characteristic of the β-structure while the dodecapeptide spectra show the presence of β-turn which indicates the stability of the β-turn at this chain length. The IR spectra show that in the solid state at room temperature all investigated peptides assume essentially a β-turn except the tetrapeptide which present evidence of antiparallel β-structure. The β-turn contribution in the IR spectra increases with the increase of the chain length of the peptide.

Cholesterol in Serum and Lipoprotein Fractions

1956 ◽  
Vol 2 (3) ◽  
pp. 145-159 ◽  
Author(s):  
Joseph T Anderson ◽  
Ancel Keys
Keyword(s):  
Human Serum ◽  
Total Cholesterol ◽  
Filter Paper ◽  
Room Temperature ◽  
Paper Electrophoresis ◽  
Cholesterol Content ◽  
Intraindividual Variability ◽  
Detailed Data ◽  
The Stability ◽  
Source Of Error

Abstract 1. Methods are described for the separation, by paper electrophoresis and by cold ethanol, of α- and β-lipoproteins in 0.1 ml. of serum, with subsequent analysis of cholesterol in the separated portions. 2. It is shown that both methods of separation yield separated fractions containing substantially the same amounts of cholesterol. 3. Detailed data are given on the errors of measurement for total cholesterol and for cholesterol in the separated lipoprotein fractions. 4. Studies are reported on the stability of cholesterol in stored serum and on paper electrophoresis strips. It is shown that simple drying on filter paper causes no change in cholesterol content and yields a product that is stable for many weeks at ordinary room temperature. 5. The sources of variability in human serum cholesterol values are examined and it is shown that spontaneous intraindividual variability is a much greater source of error than the errors of measurement with these methods.

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