scholarly journals Photo- and thermoinduced ring opening reaction of 2[(1,3,3-trimethylindoline-2(1H)-yliden)propen-1-yl]-3,3-dimethylindolino[1,2-b]-oxazolidine in polymer films

2004 ◽  
Vol 2 (2) ◽  
pp. 290-301
Author(s):  
I. Petkov ◽  
F. Charra ◽  
J Nunzi ◽  
T. Deligeorgiev
Keyword(s):  
Polymer Films ◽  
Ring Opening ◽  
Uv Light ◽  
Absorption Peak ◽  
Ring Opening Reaction ◽  
Radiation Induced ◽  
Relationship Of ◽  
The Relationship

AbstractThe influence of UV light and temperature on poly(methylmethacrylate) (PMMA) and poly(vinylchloride) (PVC) films, doped with 2[(1,3,3-trimethylindoline-2(1H)-yliden)propen-1-yl]-3,3-dimethylindolino[1,2-b]-oxazolidine has been investigated. The radiation-induced colour was analyzed spectrophotometrically at the maximum of the absorption peak at 560 nm. The effect of the temperature on unirradiated and irradiated films was studied. The results demonstrate a strong photochromic and a weak thermochromic behaviour of the PMMA and PVC films. The relationship of photocolouration-thermal decolouration is discussed based on the spectral results reported here.

Evaluation of Reflectance Fluorodensitometry for Measuring Aflatoxins on Thin Layer Plates

1971 ◽  
Vol 54 (4) ◽  
pp. 870-873
Author(s):  
Walter A Pons
Keyword(s):  
Thin Layer ◽  
Silica Gel ◽  
Uv Light ◽  
Plate Surface ◽  
Coefficients Of Variation ◽  
Standard Application ◽  
Tlc Plates ◽  
Relationship Of ◽  
The Relationship

Abstract A reflectance fluorodensitometer employing illumination of chromatograms with longwave UV light at 45° angles to the plate surface and measurement of reflected fluorescence at 90° was found to be suitable for measuring aflatoxins on silica gel-coated thin layer plates. The relationship of peak area vs. concentration was linear for 1–20 ng aflatoxins B1 and G1/ spot. Degradation of aflatoxins was slight. Five repetitive scans of the same chromatogram containing 5 ng each of B1 and G1 reduced the recorded areas an average of 1% per scan. Consecutive scans of 8 identical standard chromatograms containing 5 ng each of B1 and G1 and 1.5 ng each of B2 and G2 showed a reproducibility, as measured by coefficients of variation, of ±4–5% (B1 and G1) and ±5–9% (B2 and G2), representing the combined errors of standard application, TLC development, and scanning. Analysis of aflatoxins in purified sample extracts from 6 contaminated oilseed meals, 3–500 μg afla toxins/kg, in which the same TLC plates were scanned by a transmission densitometer and the reflectance densitometer yielded essentially equivalent values.

Problem of the Relationship of the Developed Oncological Disease with Radiation in Conditions of Production

2021 ◽  
Vol 65 (6) ◽  
pp. 76-82
Author(s):  
I. Galstyan ◽  
V. Nugis ◽  
F. Torubarov ◽  
B. Kukhta ◽  
M. Konchalovsky ◽  
...  
Keyword(s):  
Russian Federation ◽  
Oncological Disease ◽  
Foreign Countries ◽  
Radiation Induced ◽  
The Russian Federation ◽  
Relationship Of ◽  
The Relationship

Introduction. Compensation programs for radiation-induced diseases in some foreign countries. The data presented in UN documents. The linkage between irradiation and certain diseases in the Russian Federation. Conclusion.

Synthesis, Photochromism and Fluorescent Switch of 1-(2-methyl-1-benzofuran-3-yl)-2-(2-methyl-5-(4-benzylamine)-3-thienyl)) perfluorocyclopentene

2014 ◽  
Vol 1003 ◽  
pp. 47-50 ◽  
Author(s):  
Zhao Yan Tian ◽  
Shi Qiang Cui ◽  
Shou Zhi Pu
Keyword(s):  
Response Time ◽  
Ring Opening ◽  
Color Change ◽  
Uv Light ◽  
Amorphous Film ◽  
Acetonitrile Solution ◽  
Fluorescent Properties ◽  
Photochromic Behavior ◽  
Fluorescent Switch ◽  
Ring Opening Reaction

A photochromic diarylethene of 1-(2-methyl-1-benzofuran-3-yl)-2-(2-methyl-5-(4-benzylamine)-3-thienyl)) perfluorocyclopentene was synthesized and characterized. Upon irradiation with UV light with the extended response time, the diarylethene underwent a ring opening reaction to produce opened forms and color change both in solution and in a PMMA amorphous film. Its properties, including photochromic behavior and fluorescent properties have been investigated. The results showed the compound exhibited good photochromism in acetonitrile solution and in PMMA amorphous film.

scholarly journals Oxidation Level and Glycidyl Ether Structure Determine Thermal Processability and Thermomechanical Properties of Arabinoxylan-Derived Thermoplastics

2020 ◽  
Author(s):  
Parveen Kumar Deralia ◽  
Aline Maire du Poset ◽  
Anja Lund ◽  
Anette Larsson ◽  
Anna Ström ◽  
...  
Keyword(s):  
Thermal Processing ◽  
Ring Opening ◽  
Glycidyl Ether ◽  
Thermomechanical Properties ◽  
Subsequent Reduction ◽  
Glycidyl Ethers ◽  
Dramatic Difference ◽  
Molar Substitution ◽  
Relationship Of ◽  
The Relationship

Herein we present arabinoxylan (AX)-based thermoplastics obtained by ring opening oxidation and subsequent reduction (dA-AX) combined with hydrophobization with three different glycidyl ethers [n-butyl (BuGE), isopropyl (iPrGE) and 2-ethylhexyl (EtHGE) glycidyl ether]. We also present the relationship of structural composition, thermal processing and thermomechanical properties. The BuGE and iPrGE etherified dA-AXs showed glass transition temperatures (T<sub>g</sub>) far below their degradation temperatures and gave thermoplastic materials when compression-molded at 140˚C. The BuGE (3 mole) etherified dA-AX films at 19 and 31 % oxidation levels exclusively exhibit 244 % (±42) and 267 % (±72) elongation. In contrast, iPrGE-dA-AX samples with shorter and branched terminals in the side chains had maximum 60 % (±19) elongation. The dramatic difference in elongation is assumed to be due to the presence of longer alkoxide chains, higher molar substitution and dual T<sub>g</sub> for the BuGE samples. Such superior elongation of AX thermoplastic films and its relationship with molar substitution and T<sub>g</sub> has not been reported before.

Photocatalytic Degradation of Carbaryl over Novel MWNT-TiO2 Nanocomposite under Visible Light Irradiation

2011 ◽  
Vol 233-235 ◽  
pp. 476-480
Author(s):  
Ke Dai ◽  
Hai Bo Chen ◽  
Xu Li ◽  
Hao Chen ◽  
Qiao Yun Huang
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Ring Opening ◽  
Uv Light ◽  
Light Irradiation ◽  
Photodegradation Efficiency ◽  
Uv Light Irradiation ◽  
Ring Opening Reaction ◽  
Visible Light Driven ◽  
Direct Growth

The MWNT-TiO2nanocomposite was synthesized via direct growth of TiO2nanoparticles on the surface of the functionalized MWNTs by the hydrothermal treatment and utilized as the photocatalyst in the carbaryl degradation under both visible light and UV light irradiation. Visible-light-driven activity and enhanced UV-light-driven activity are both achieved as the composite MWNTs with TiO2can efficiently enhance the light absorption and charge separation and then photocatalytic activity. The photodegradation efficiency of carbaryl was examined by HPLC and IC techniques, which demonstrates that carbaryl can be readily degraded under visible light irradiation. Based on the obtained experimental results, assisted with the computer simulation of carbaryl molecule on PM3 level, it is presumed that the degradation of carbaryl starts with the break of N21-C23 and C19-N21 bonds and ends in the generation of naphthalen-1-ol before the ring-opening reaction.

ANALYSIS OF THE LETHAL EFFECTS OF LOW-DOSE RADIATION ON GLIOMA CELLS: RELATIONSHIP OF THE BYSTANDER EFFECT AND METAL ELEMENTS

2011 ◽  
Vol 21 (01n02) ◽  
pp. 47-54 ◽  
Author(s):  
SEIICHI WADA ◽  
MAUKO SUDO ◽  
SAKIKO TAMURA ◽  
TAKEHIKO KAKIZAKI ◽  
NOBUHIKO ITO ◽  
...  
Keyword(s):  
Cell Death ◽  
Low Dose ◽  
Bystander Effect ◽  
Low Dose Radiation ◽  
Metal Elements ◽  
Zn Concentration ◽  
Radiation Induced ◽  
Radiation Induced Bystander Effect ◽  
Relationship Of ◽  
The Relationship

Investigation of the radiation-induced bystander effect plays an important role in the understanding of the mechanisms of radiation response after low-dose irradiation. Sphingomyelinase (SMase) was activated by radiation and required the metal element for its activation. For further elucidation of the bystander effect, we investigated the relationship between its induction by acid SMase and a factor secreted from the irradiated tumor cells. In the cell culture medium transfer experiment after irradiation at a dose of 0.1 Gy , cell death was induced in non-irradiated cells. However, when cells received prior treatment with SMase inhibitor, cell death was not induced. When fluctuations in the activation of SMase and metal elements were detected, both intracellularly and extracellularly after irradiation, an increase in SMase activity and Zn concentration occurred within the cells at 5 min and outside of the cells at 15 min after irradiation. This increase in zinc concentration at 15 min after irradiation was suppressed by treatment with SMase inhibitor. These results suggest that activation of SMase, which is related to the bystander effect, is dependent on zinc.

Synthesis and Properties of 1-(3,5-dimethyl-4-isoxazole)-2-(2-methyl-(5-ethynyl)-3-thienyl)perfluorocyclopentene

2014 ◽  
Vol 1078 ◽  
pp. 82-85
Author(s):  
Mei Li Cai ◽  
Zhao Yan Tian ◽  
Shi Qiang Cui ◽  
Shou Zhi Pu
Keyword(s):  
Response Time ◽  
Ring Opening ◽  
Color Change ◽  
Uv Light ◽  
Order Reaction ◽  
First Order Reaction ◽  
Fluorescence Properties ◽  
First Order ◽  
Ring Opening Reaction ◽  
Hexane Solution

A new photochromic diarylethene of 1-(3,5-dimethyl-4-isoxazole)-2- (2-methyl-(5-ethynyl)-3-thienyl) perfluorocyclopentene (1o) was synthesized. Its photochromic and fluorescence properties were investigated systematically. Upon irradiation with UV light with the extended response time, the diarylethene underwent a ring opening reaction to produce closed forms and color change in solution. The results showed the compound exhibited good photochromism in hexane solution. The kinetic experiments showed that the cyclization and cycloreversion processes were zeroth and first order reaction, respectively. Moreover, diarylethene1oalso exhibited obviously fluorescence switches along with the photochromism.

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