Degradation kinetics of poly(lactic-co-glycolic) acid block copolymer cast films in phosphate buffer solution as revealed by infrared and Raman spectroscopies

2011 ◽  
Vol 96 (10) ◽  
pp. 1882-1889 ◽  
Author(s):  
Elisabeth Vey ◽  
Caroline Rodger ◽  
Jonathan Booth ◽  
Mike Claybourn ◽  
Aline F. Miller ◽  
...  
2008 ◽  
Vol 93 (10) ◽  
pp. 1869-1876 ◽  
Author(s):  
Elisabeth Vey ◽  
Caroline Roger ◽  
Liz Meehan ◽  
Jonathan Booth ◽  
Mike Claybourn ◽  
...  

Author(s):  
V. V. Skarga ◽  
E. V. Nevezhin ◽  
A. А. Matrosov ◽  
V. V. Negrebetsky ◽  
M. V. Malakhov

Photooxidized psoralen solutions possess a variety of biological effects, which implementation mechanism may presumably involve hydroperoxides. Here, the hydroperoxide content in photooxidized psoralen solutions was assessed using photometric FOX assay (from Ferrous Oxidation + Xylenol Orange). FOX reagent with 10× content of Xylenol Orange, modified for quantitative analysis of up to 50 μM of hydroperoxides in aqueous phase was used in experiments. During photooxidation of 0.1 mM psoralen in phosphate buffer solution, hydroperoxide production increases with dose of UVA irradiation (~2.5 μM eq. of H2O2 for dose of 252 kJ/m2 and ~11 μM eq. of H2O2 for dose of 1512 kJ/m2) and reaches ~16.5 μM eq. of H2O2 at the highest dose investigated (3024 kJ/m2). A comparison of kinetics of psoralen photolysis and hydroperoxide generation allows us to suggest that generation of hydroperoxide results from the secondary photochemical processes involving psoralen photoproducts, presumably from photoinduced autooxidation of aldehydic photoproducts of psoralen.


2011 ◽  
Vol 284-286 ◽  
pp. 1764-1769 ◽  
Author(s):  
Vitalijs Lakevics ◽  
Janis Locs ◽  
Dagnija Loca ◽  
Valentina Stepanova ◽  
Liga Berzina-Cimdina ◽  
...  

Sorption experiments of bovine serum albumin (BSA) on hydroxyapatite (HAp) ceramic granules, prepared at three temperatures 900°C, 1000°C and 1150°C were performed at room temperature 18,6 °C and phosphate buffer, pH 5,83; 6.38 and 7,39. Thermal treatment contributed to the decrease of bovine serum albumin immobilization indicating that sorption process depended on HAp ceramics specific surface area and pH values of phosphate buffer solution. However, it was confirmed that granule size was also an important parameter for bovine serum albumin adsorption. As a result of these experiments, the most appropriate adsorption conditions and phosphate buffer pH values influence on to BSA sorption were analyzed.


2000 ◽  
Vol 63 (6) ◽  
pp. 703-708 ◽  
Author(s):  
MARCY A. WISNIEWSKY ◽  
BONITA A. GLATZ ◽  
MARK L. GLEASON ◽  
CHERYLL A. REITMEIER

The objectives of this study were to determine if washing of whole apples with solutions of three different sanitizers (peroxyacetic acid, chlorine dioxide, or a chlorine-phosphate buffer solution) could reduce a contaminating nonpathogenic Escherichia coli O157:H7 population by 5 logs and at what sanitizer concentration and wash time such a reduction could be achieved. Sanitizers were tested at 1, 2, 4, 8, and 16 times the manufacturer's recommended concentration at wash times of 5, 10, and 15 min. Whole, sound Braeburn apples were inoculated with approximately 1 × 108 or 7 × 106 CFU per apple, stored for 24 h, then washed with sterile water (control) or with sanitizers for the prescribed time. Recovered bacteria were enumerated on trypticase soy agar. Washing with water alone reduced the recoverable population by almost 2 logs from the starting population; this can be attributed to physical removal of organisms from the apple surface. No sanitizer, when used at the recommended concentration, reduced the recovered E. coli population by 5 logs under the test conditions. The most effective sanitizer, peroxyacetic acid, achieved a 5-log reduction when used at 2.1 to 14 times its recommended concentration, depending on the length of the wash time. The chlorine-phosphate buffer solution reduced the population by 5 logs when used at 3 to 15 times its recommended concentration, depending on wash time. At no concentration or wash time tested did chlorine dioxide achieve the 5-log reduction.


2018 ◽  
Vol 10 (11) ◽  
pp. 1362-1371 ◽  
Author(s):  
Mallappa Mahanthappa ◽  
Nagaraju Kottam ◽  
Shivaraj Yellappa

The simultaneous electroanalysis of acetaminophen (AC), guanine (G) and adenine (A) was successfully achieved on the zinc sulphide nanoparticles-modified carbon paste electrode (ZnS NPs/CPE) in phosphate buffer solution (PBS).


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