Synthesis, characterization, biological activity, and thermal stability of new styrenic polymer having pendant ketone and its some derivatives

2012 ◽  
Vol 53 (7) ◽  
pp. 1383-1393 ◽  
Author(s):  
Ibrahim Erol ◽  
Zehra Şahin ◽  
Levent Özcan
Keyword(s):  
Thermal Stability ◽  
Biological Activity ◽  
Styrenic Polymer ◽  
Thermal Stability Of

scholarly journals Influence of ZrO2 Addition on Structural and Biological Activity of Phosphate Glasses for Bone Regeneration

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4058
Author(s):  
M. Mohan Babu ◽  
P. Syam Prasad ◽  
P. Venkateswara Rao ◽  
S. Hima Bindu ◽  
A. Prasad ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Biological Activity ◽  
Incubation Time ◽  
Sample Surface ◽  
Glass Forming Ability ◽  
Phosphate Glasses ◽  
Bioactive Materials ◽  
Glass Forming ◽  
Before And After ◽  
Thermal Stability Of

Zirconium doped calcium phosphate-based bioglasses are the most prominent bioactive materials for bone and dental repair and regeneration implants. In the present study, a 8ZnO–22Na2O–(24 − x)CaO–46P2O5–xZrO2 (0.1 ≤ x ≤ 0.7, all are in mol%) bioglass system was synthesized by the conventional melt-quenching process at 1100 °C. The glass-forming ability and thermal stability of the glasses were determined by measuring the glass transition temperature (Tg), crystallization temperature (Tc), and melting temperature (Tm), using differential thermal analysis (DTA). The biological activity of the prepared samples was identified by analyzing X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy-energy dispersive spectra (SEM-EDS), before and after immersion in simulated body fluid (SBF) for various intervals of 0, 1 and 5 days, along with the magnitude of pH and the degradation of glasses also evaluated. The obtained results revealed that the glass-forming ability and thermal stability of glasses increased with the increase in zirconia mol%. The XRD, FTIR, and SEM-EDS data confirmed a thin hydroxyapatite (HAp) layer over the sample surface after incubation in SBF for 1 and 5 days. Furthermore, the development of layer found to be increased with the increase of incubation time. The degradation of the glasses in SBF increased with incubation time and decreased gradually with the increase content of ZrO2 mol% in the host glass matrix. A sudden rise in initial pH values of residual SBF for 1 day owing to ion leaching and increase of Ca2+ and PO43− ions and then decreased. These findings confirmed the suitability of choosing material for bone-related applications.

Thermal Stability of Enterotoxins in Food

1976 ◽  
Vol 39 (6) ◽  
pp. 432-438 ◽  
Author(s):  
S. R. TATINI
Keyword(s):  
Thermal Stability ◽  
Biological Activity ◽  
Food System ◽  
Detection System ◽  
Urea Treatment ◽  
Serological Assay ◽  
Proteose Peptone ◽  
Complete Destruction ◽  
Whole Milk ◽  
Thermal Stability Of

Biological and serological properties of staphylococcal enterotoxins exhibit remarkable thermal stability. The slope of the thermal destruction curve (z value) for enterotoxin A or D is 27–28 C and it is 32 C for enterotoxin B regardless of the initial concentration of enterotoxin, the heating medium, or the assay system used to detect the enterotoxin. Thermal stability of enterotoxins is influenced by the nature of the food, pH, presence of NaCl, etc., and the type of enterotoxin; enterotoxin A is relatively more stable to heat at pH 6.0 (or higher) than at pH 4.5–5.5. Enterotoxin D is relatively more stable at pH 4.5–5.5 than at pH 6.0 or greater. Heat treatments commonly used in food processing, that is pasteurization (72 C for 15 sec) or ultrahigh temperature heating (290 F for 9 sec) in a “Spiratherm” Unit of Fluid whole milk, or smoking and heating of cured sausage to 70–100 C, or heating of Cheddar cheese to 70–90 C, are not effective for complete destruction (to levels below detection by the microslide serological assay) of enterotoxin A or D when present initially at levels normally expected to be found in foods (0.5–1.0 μg per 100 ml or g). Enterotoxin A or B (30 μg/ml) heated at 100 C for 25 min in saline, containing 2% gelatin and 0.3% proteose peptone and at pH 7.0, retained biological activity toward humans with a suggestion of increased biological activity after heat treatment, especially with enterotoxin A. The length of time required at a given temperature for complete destruction of enterotoxin in a given food system depends upon the sensitivity of the detection system used and the amount of food sample used for recovery of the enterotoxin. Treatment of heated enterotoxin A or D with urea and its removal by dialysis before serological assay, increased the recovery of enterotoxin by almost 4-fold as compared to controls which were simply heated and were not treated with urea. Enterotoxin A or D present initially at 1 μg/ml in whole milk (using 2 ml for recovery of enterotoxin with urea treatment following heating and assay by the micro slide method of Casman and Bennett) was found to withstand heating of milk at 121.1 C for 15 min. In the absence of urea treatment of heated toxins in milk, both toxins were found to be inactivated (to less than 0.02 μg/ml (within 15 min at 121.1 C; between 13.8–14.8 min for toxin A and 12.8–13.8 min for toxin D.

Effect of PEG molecular weight and linking chemistry on the biological activity and thermal stability of PEGylated trypsin

2008 ◽  
Vol 357 (1-2) ◽  
pp. 252-259 ◽  
Author(s):  
Benjaporn Treetharnmathurot ◽  
Chitchamai Ovartlarnporn ◽  
Juraithip Wungsintaweekul ◽  
Ruth Duncan ◽  
Ruedeekorn Wiwattanapatapee
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Biological Activity ◽  
Thermal Stability Of

scholarly journals THERMAL STABILITY AS A PROGNOSTIC INDICATOR OF CONSERVATION OF LIVE EMBRYONIC SMALLPOX VACCINE (TEOVAC) DURING STORAGE

2016 ◽  
pp. 56-62
Author(s):  
V. A. Zhukov ◽  
S. V. Kokorev ◽  
S. V. Rogozhkina ◽  
D. G. Melnikov ◽  
A. I. Terentiev ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Biological Activity ◽  
Prognostic Indicator ◽  
Smallpox Vaccine ◽  
Stress Tests ◽  
Warranty Period ◽  
Thermal Stability Of

Aim. Determination of values of coefficients of thermal stability of TEOVac for prognosis of conservation of the vaccine (specific biological activity) during the process of warranty period storage. Materials and methods. TEOVac (masticatory tablets) in primary packaging was kept at increased temperature (accelerated and stress-tests) and at the conditions established by PAP for the preparation (long-term tests). Biological activity of the vaccine was determined by titration on 12-day chicken embryos. Results. A correlation between the value of coefficients of thermal stability and conservation of the prepared series of the condition preparation at the final date of storage was experimentally established. Conclusion. Coefficients of thermal stability could be used as a prognostic indicator of quality of the produced pelleted formulation of the preparation for evaluation of conservation of the vaccine during warranty period storage.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

Microstructure studies of tungsten silicide schottky contacts on Gaas

1987 ◽  
Vol 45 ◽  
pp. 328-329
Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie
Keyword(s):  
Thermal Stability ◽  
Field Effect Transistors ◽  
Schottky Contact ◽  
Schottky Contacts ◽  
Excellent Thermal Stability ◽  
Barrier Heights ◽  
Gaas Substrates ◽  
Film Adhesion ◽  
Threshold Voltages ◽  
Thermal Stability Of

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.

Thermal stability of Al-Cu-Fe icosahedral alloys

1991 ◽  
Vol 1 (12) ◽  
pp. 1823-1836 ◽  
Author(s):  
M. Bessière ◽  
A. Quivy ◽  
S. Lefebvre ◽  
J. Devaud-Rzepski ◽  
Y. Calvayrac
Keyword(s):  
Thermal Stability ◽  
Thermal Stability Of

Practical criteria for the thermal stability of a unidimensional superconductor

1994 ◽  
Vol 4 (4) ◽  
pp. 653-657
Author(s):  
B. Bonzi ◽  
M. El Khomssi ◽  
H. Lanchon-Ducauquis
Keyword(s):  
Thermal Stability ◽  
Thermal Stability Of

Time and thermal stability of magnetic properties of amorphous Fe80TM3B17 alloys

1998 ◽  
Vol 08 (PR2) ◽  
pp. Pr2-63-Pr2-66 ◽  
Author(s):  
R. Varga ◽  
P. Vojtaník ◽  
A. Lovas
Keyword(s):  
Thermal Stability ◽  
Magnetic Properties ◽  
Thermal Stability Of
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