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An optical system with aberrations on diffraction integrals written in terms of a generalized ABCD matrix

100%
Zhao C., Tan W.
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vol. 6
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issue 4
895-902
EN
Abstract: In this paper, we consider the transformation of a ray beam as it passes through an optical system containing a glass plate with parallel surfaces inclined to the optical axis at the Brewster’s angle, by investigating the effects of the optical system on amplitude and phase distributions. By applying generalized matrix optics and diffraction integrals and considering the influence of a quarter of a wavelength of aberration on the transmitted amplitude and phase distributions at the focus of a de-collimating lens, we find that the central peak amplitude descends from 1.0 to 0.8 and the phase distortion is less than π/2. The general feature of the amplitude distribution shows an elongation along the y-axis perpendicular to the optical axis in the direction of tilt of the inclined plate, and conforms to the inclination direction of the glass plate.
2
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An Outline of Cardiogenesis

88%
Piotrowski K., Mędrek K., Zajączek S.
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2014
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vol. 4
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issue 1
6-8
EN
The paper presents a description of the development of the human heart based on the present state of knowledge cytogenetics and molecular genetics. Despite the complexity of the genetic mechanisms described, the authors emphasize that it may be just a slice patterns in kardiogenezie. Aberrations and mutations lead to the formation of congenital heart defects in both isolated and components of genetic syndromes.
3
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Wigner transform approach to dynamic-variable partially coherent laser beam characterization

75%
Jabczyński J., Gontar P., Gorajek Ł.
Bulletin of the Polish Academy of Sciences: Technical Sciences
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2020
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issue 1
4
Content available remote

Antimutagenic effects of aqueous fraction of Myristica fragrans (Houtt.) leaves on Salmonella typhimurium and Mus musculus

75%
Akinboro A., Bin Mohamed K., Asmawi M., Yekeen T.
Acta Biochimica Polonica
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2014
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vol. 61
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issue 4
779-785
EN
Natural plant extracts offer a promising hope in the prevention/treatment of cancer arising from genetic mutations. This study evaluated in vitro and in vivo mutagenic and antimutagenic effects of aqueous fraction of Myristica fragrans (AFMF) leaves on TA100 strain of Salmonella typhimurium and Mus musculus (Male Swiss albino mice), respectively. The antioxidant activity of AFMF against 2,2-diphenyl-1-picrylhydrazyl (DPPH), total phenolic and flavonoid contents were determined, followed by its phytochemical elucidation using the Ultra Performance Liquid Chromatography technique (UPLC). The mutagenicity of AFMF at 4, 20, 50, 100, 200, 500, and 1000 µg/well was <2.0 in S. typhimurium and the induced micronucleated polychromatic and normochromatic erythrocytes at 500, 1000, 2000, and 4000 mg/kg were not significantly different from the negative control (p≥0.05). The mutagenic activity of benzo[a]pyrene and cyclophosphamide was significantly suppressed above 50.0% throughout the tested concentrations. Fifty percent of the free radicals from DPPH were scavenged by AFMF at 0.11 mg/ml. Total phenolic and flavonoid contents of AFMF were 51.0 mg GAE/g and 27 mg QE/g, respectively. Rutin was elucidated by the UPLC technique, and thereby suspected to be the phytochemical responsible for the observed antimutagenic activity. Thus far, AFMF seems to contain a promising chemotherapeutic agent for the prevention of genetic damage that is crucial for cancer development.
5
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Evaluation of antioxidant, antimutagenic, and lipid peroxidation inhibitory activities of selected fractions of Holarrhena floribunda (G. Don) leaves

75%
Badmus J., Odunola O., Yekeen T., Gbadegesin A., Fatoki J., Godo M., Oyebanjo K., Hiss D.
Acta Biochimica Polonica
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2013
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vol. 60
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issue 3
435-442
EN
Exposure to environmental pollutants often leads to an upsurge in the production of reactive oxygen species (ROS). ROS oxidize cellular fatty acids to produce lipid peroxyl radicals, subsequently transformed into lipid peroxides, which decrease membrane fluidity and increase the activity of various enzymes implicated in degenerative diseases and cancer formation. Edible plants that contain exogenous compounds like curcumeroid, β-carotene, turmeric, and so on, protect the aerobic cells from oxidation of free radicals. This study thus evaluates antioxidant and antimutagenic activities of ethyl acetate, aqueous and methanolic fractions of Holarrhena floribunda leaves. Inhibitory activities of the ethyl acetate fraction on Fe2+-induced lipid peroxidation in hen egg yolk; rat liver and brain tissues were also evaluated. The Allium cepa root assay was used to evaluate antimutagenic activity. Results showed that the ethyl acetate scavenged DPPH, OH•, and •O2- much stronger than other fractions, as evidenced by its lowest respective IC50 values. All the fractions displayed antimutagenic activities against cyclophosphamide-induced chromosomal aberrations. Likewise, all the fractions induced a reduction in mitotic index, a hallmark of cytotoxicity in the root meristem of Allium cepa. The decrease in mitotic index was most profound for the ethyl acetate fraction, which also demonstrated a significant lipid peroxidation inhibitory activity in the liver and brain homogenates, but not in egg yolk, compared with the ascorbic acid standard. In general, the results suggest that the ethyl acetate fraction might contain beneficial phytochemicals that should be explored as novel candidates for preclinical drug development.
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