ChemInform Abstract: The Role of the Torsion of the Phenyl Moiety in the Mechanism of Stimulated UV Light Generation in 2-Phenylbenzazoles

ChemInform ◽  
2010 ◽  
Vol 23 (20) ◽  
pp. no-no
Author(s):  
J. CATALAN ◽  
E. MENA ◽  
F. FABERO ◽  
F. AMAT-GUERRI
Keyword(s):  
Uv Light ◽  
Light Generation ◽  
Phenyl Moiety

The role of the torsion of the phenyl moiety in the mechanism of stimulated ultraviolet light generation in 2‐phenylbenzazoles

1992 ◽  
Vol 96 (3) ◽  
pp. 2005-2016 ◽  
Author(s):  
Javier Catalán ◽  
Elena Mena ◽  
Fernando Fabero ◽  
Francisco Amat‐Guerri
Keyword(s):  
Ultraviolet Light ◽  
Light Generation ◽  
Phenyl Moiety

scholarly journals 1047 PSEUDOMONADS AND THE ROLE OF-THE ANTIBIOTICS IN THE CONTROL OF GREEN MOLD OF LEMONS.

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 578e-578
Author(s):  
J.S. Parham ◽  
J.L. Smilanick
Keyword(s):  
Uv Light ◽  
Inhibition Zone ◽  
Sulfanilic Acid ◽  
Pseudomonas Cepacia ◽  
E Coli ◽  
Green Mold ◽  
Tlc Plates ◽  
Stable Mutant ◽  
Inhibition Zones

Pseudomonas cepacia LT412W reduced green mold on lemons caused by Penicillium digitatum. It produces phenylpyrrole antibiotics which cause inhibition zones in co-culture with the pathogen. Their role in control of the disease was investigated. Mutagenesis of P. cepacia (rifampicin resistant) was performed by mating it with E. coli S-17 pSUP1021 (kanamycin resistant), which carries the transposon Tn5. Transconjugate selection and screening for absence of inhibition zones identified a stable mutant. Growth of parent and mutant were comparable. When the mutant was co-cultured with the pathogen on lemon albedo agar, no inhibition zone appeared. Similar co-culture on potato dextrose agar with tryptophan (0.05 g/L), a precursor of phenylpyrroles, did not induce inhibition zones. This suggests the mutation is not in tryptophan biosynthesis. Parent and mutant were assayed for phenylpyrroles. They were cultured in nutrient broth, centrifuged, and the cells extracted with acetone. The extract was dried and dissolved in chloroform. It was spotted on nano-SIL Cl8 TLC plates, run one hour (methanol:acetonitrile:water, 1:1:1), dried, developed with sulfanilic acid, and observed under UV light. The relative mobility of spots from extracts of the parent matched phenylpyrroles, whereas the mutant produced none. Control of decay by the mutant and parent were equal, suggesting no role for phenylpyrroles in suppression of the disease.

scholarly journals Computational study on the mechanism of metal-free photochemical borylation of aryl halides

2021 ◽  
Author(s):  
Chenhao Tu ◽  
Nana Ma ◽  
Qingli Xu ◽  
Wenyue Guo ◽  
Lanxin Zhou ◽  
...  
Keyword(s):  
Density Functional ◽  
Uv Light ◽  
Computational Study ◽  
Halogen Bond ◽  
Bond Cleavage ◽  
Aryl Halides ◽  
Homolytic Cleavage ◽  
Functional Theory ◽  
Aryl Radicals

C-radical borylation is an significant approach for the construction of carbon−boron bond. Photochemical borylation of aryl halides successfully applied this strategy. However, precise mechanisms, such as the generation of aryl radicals and the role of base additive(TMDAM) and water, remain controversy in these reactions. In this study, photochemical borylation of aryl halides has been researched by density functional theory (DFT) calculations. Indeed, the homolytic cleavage of the C−X bond under irradiation with UV-light is a key step for generation of aryl radicals. Nevertheless, the generation of aryl radicals may also undergo the process of single electron transfer and the heterolytic carbon-halogen bond cleavage sequence, and the latter is favorable during the reaction.

Role of ZnO Nanoparticles for improvement of Antibacterial Activity in Food Packaging

2021 ◽  
pp. 128-131
Author(s):  
Saira Sehar ◽  
Amiza Amiza ◽  
I. H Khan
Keyword(s):  
Antimicrobial Activity ◽  
Particle Size ◽  
Surface Area ◽  
Zno Nanoparticles ◽  
Food Packaging ◽  
Antimicrobial Agents ◽  
Uv Light ◽  
Zno Nps ◽  
Long Time

Nanotechnology advancement leads to development of antimicrobial agents like ZnO nanoparticles. These nanoparticle have their main applications in food packaging. when these nanoparticles incorporate into the food surface, it will kill all bacterias residing on the surface and food become free of bacteria. In this way, food can be stored for a long time because its shelf life is improved. Antimicrobial activity of ZnO nanoparticles can be improved by increasing surface area, reducing particle size and large concentration of ZnO –NPS. Antimicrobial activity increases by increasing intensity of UV light. As UV light fall on ZnO nanoparticles, it increases ZnO surface area and hence anrtimicrobial activity will be increased. Exact mechanism of Antimicrobial activity is still unknown but some processes have been presented.

Accumulation of soluble and nucleolar-associated p53 proteins following cellular stress

2001 ◽  
Vol 114 (10) ◽  
pp. 1867-1873 ◽  
Author(s):  
S.A. Klibanov ◽  
H.M. O'Hagan ◽  
M. Ljungman
Keyword(s):  
Target Genes ◽  
Uv Light ◽  
Human Fibroblasts ◽  
Proteasome Inhibition ◽  
Tumor Suppressor P53 ◽  
Mdm2 Protein ◽  
Transcription Inhibitor ◽  
Cellular Stresses ◽  
In Cells

The tumor suppressor p53 is a nucleocytoplasmic shuttling protein that accumulates in the nucleus of cells exposed to various cellular stresses. One important role of nuclear p53 is to mobilize a stress response by transactivating target genes such as the p21(Waf1) gene. In this study, we investigated more closely the localization of p53 in cells following various stresses. Immunocytochemistry of fixed human fibroblasts treated with either UV light, the kinase and transcription inhibitor DRB or the proteasome inhibitor MG132 revealed abundant p53 localized to the nucleus. When cells treated with UV or DRB were permeabilized prior to fixation to allow soluble proteins to diffuse, the nuclear p53 signal was abolished. However, in cells treated with MG132, residual p53 localized to distinct large foci. Furthermore, nucleolin co-localized with p53 to these foci, suggesting that these foci were nucleolar structures. Interestingly, the MDM2 protein was found to co-localize with p53 to nucleolar structures following proteasome inhibition. Our results suggest that the p53 proteins accumulating in the nucleus following UV-irradiation or blockage of transcription are freely soluble and, thus, should be able to roam the nucleus to ensure high occupancy of p53 binding sites. However, inhibition of proteasome activity may be a unique stress in that it leads to the sequestering of p53 proteins to the nucleolus, thereby blunting the p53-mediated transactivation of target genes.

scholarly journals The effect of temperature on persistence of SARS-CoV-2 on common surfaces

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Shane Riddell ◽  
Sarah Goldie ◽  
Andrew Hill ◽  
Debbie Eagles ◽  
Trevor W. Drew
Keyword(s):  
Uv Light ◽  
Risk Mitigation ◽  
Survival Rates ◽  
Environmental Stability ◽  
Effect Of Temperature ◽  
Viral Loads ◽  
Different Temperatures ◽  
C 30 ◽  
D Values

Abstract Background The rate at which COVID-19 has spread throughout the globe has been alarming. While the role of fomite transmission is not yet fully understood, precise data on the environmental stability of SARS-CoV-2 is required to determine the risks of fomite transmission from contaminated surfaces. Methods This study measured the survival rates of infectious SARS-CoV-2, suspended in a standard ASTM E2197 matrix, on several common surface types. All experiments were carried out in the dark, to negate any effects of UV light. Inoculated surfaces were incubated at 20 °C, 30 °C and 40 °C and sampled at various time points. Results Survival rates of SARS-CoV-2 were determined at different temperatures and D-values, Z-values and half-life were calculated. We obtained half lives of between 1.7 and 2.7 days at 20 °C, reducing to a few hours when temperature was elevated to 40 °C. With initial viral loads broadly equivalent to the highest titres excreted by infectious patients, viable virus was isolated for up to 28 days at 20 °C from common surfaces such as glass, stainless steel and both paper and polymer banknotes. Conversely, infectious virus survived less than 24 h at 40 °C on some surfaces. Conclusion These findings demonstrate SARS-CoV-2 can remain infectious for significantly longer time periods than generally considered possible. These results could be used to inform improved risk mitigation procedures to prevent the fomite spread of COVID-19.

scholarly journals The Drosophila Model: Exploring Novel Therapeutic Compounds against Neurodegenerative Diseases

Antioxidants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 623 ◽  
Author(s):  
Sun Joo Cha ◽  
Hyeon-Ah Do ◽  
Hyun-Jun Choi ◽  
Mihye Lee ◽  
Kiyoung Kim
Keyword(s):  
Neurodegenerative Diseases ◽  
Fruits And Vegetables ◽  
Uv Light ◽  
Dietary Polyphenols ◽  
Drosophila Model ◽  
Therapeutic Compounds ◽  
Novel Drug ◽  
And Oxidative Stress ◽  
Drosophila Models

Polyphenols are secondary metabolites of plants, fruits, and vegetables. They act as antioxidants against free radicals from UV light, pathogens, parasites, and oxidative stress. In Drosophila models, feeding with various polyphenols results in increased antioxidant capacity and prolonged lifespan. Therefore, dietary polyphenols have several health advantages for preventing many human diseases, including cardiovascular diseases, cancer, and neurodegenerative diseases. However, the exact role of polyphenols in neurodegenerative diseases is still yet to be completely defined. This review focuses on the most recent studies related to the therapeutic effect of polyphenols in neurodegenerative disease management and provides an overview of novel drug discovery from various polyphenols using the Drosophila model.

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