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101.
Flávio A. Carvalho Fernando B. Oda Eduardo J. Crevelin Antônio E. M. Crotti André G. dos Santos 《化学与生物多样性》2021,18(6):e2000880
Casearia sylvestris is an endemic tree of the Latin America that the essential oil (EO) has anti-inflammatory and gastroprotective actions. This study evaluates the chemical composition of the EO from the volatile fractions of in natura, fresh, and dried C. sylvestris var. sylvestris and var. lingua leaves. For both varieties, the dried leaves presented higher EO yield as compared to fresh leaves. The major EO chemical components were (E)-caryophyllene, α-humulene, germacrene D, bicyclogermacrene, spathulenol, caryophyllene oxide, and humulene epoxide II. In both varieties, the content of sesquiterpene hydrocarbons decreased and oxygenated sesquiterpenes increased on going from in natura to fresh and dried leaves, which indicated that leaf drying and hydrodistillation modified the volatile composition. The results also suggested that bicyclogermacrene and (E)-caryophyllene were oxidized during processing, to generate spathulenol and caryophyllene oxide, respectively. C. sylvestris varieties and in natura, fresh, and dried leaves differed in terms of the chemical composition of volatiles, which could affect the EO biological activities. 相似文献
102.
Jardón-Valadez Eduardo Chen Charles H. García-Garibay Mariano Jiménez-Guzmán Judith Ulmschneider Martin B. 《Food biophysics》2021,16(1):70-83
Food Biophysics - Absorption of bioactive peptides in the intestinal epithelium take place in the apical or the basolateral tight junctions of the cells. Depending on the peptide size and... 相似文献
103.
Calmasini Fabiano B. Alexandre Eduardo C. Oliveira Mariana G. Silva Fábio H. Soares António G. Costa Soraia K.P. Antunes Edson 《Journal of physiology and biochemistry》2021,77(4):557-564
Journal of Physiology and Biochemistry - Lipopolysaccharide (LPS) is a component of gram-negative bacteria wall that elicits inflammatory response in the host through the toll-like receptor 4... 相似文献
104.
105.
María Victoria Martin Diego Fernando Fiol Venkatesan Sundaresan Eduardo Julián Zabaleta Gabriela Carolina Pagnussat 《The Plant cell》2013,25(5):1573-1591
Reactive oxygen species (ROS) can function as signaling molecules, regulating key aspects of plant development, or as toxic compounds leading to oxidative damage. In this article, we show that the regulation of ROS production during megagametogenesis is largely dependent on MSD1, a mitochondrial Mn-superoxide dismutase. Wild-type mature embryo sacs show ROS exclusively in the central cell, which appears to be the main source of ROS before pollination. Accordingly, MSD1 shows a complementary expression pattern. MSD1 expression is elevated in the egg apparatus at maturity but is downregulated in the central cell. The oiwa mutants are characterized by high levels of ROS detectable in both the central cell and the micropylar cells. Remarkably, egg apparatus cells in oiwa show central cell features, indicating that high levels of ROS result in the expression of central cell characteristic genes. Notably, ROS are detected in synergid cells after pollination. This ROS burst depends on stigma pollination but precedes fertilization, suggesting that embryo sacs sense the imminent arrival of pollen tubes and respond by generating an oxidative environment. Altogether, we show that ROS play a crucial role during female gametogenesis and fertilization. MSD1 activity seems critical for maintaining ROS localization and important for embryo sac patterning. 相似文献
106.
A comparative study was performed on lysozyme modification after exposure to Fenton reagent (Fe(II)/H 2 O 2 ) or hydroxyl radicals produced by n radiation. The conditions were adjusted to obtain, with both systems, a 50% loss of activity of the modified ensemble. n radiation modified almost all types of amino acid residues in the enzyme, with little specificity. The modification order was Tyr > Met=Cys > Lys > Ile+Leu > Gly > Pro=Phe>Thr+Ala>Trp=Ser>Arg>Asp+Glu, with 42 mol of modified residues per initial mole of native enzyme. In contrast, when the enzyme was exposed to the Fenton reaction, only some types of amino acids were modified. Furthermore, a smaller number of residues (13.5) were damaged per initial mole of enzyme. The order of the modified residues was Tyr > Cys > Trp > Met >His > Ile+Leu > Val > Arg. These results demonstrate that the modifications elicited by these two free radical sources follow different mechanisms. An intramolecular free radical chain reaction is proposed to play a dominant role in the oxidative modification of the protein promoted by n radiation. 相似文献
107.
Dr Julio J. Ochoa Francisco Contreras-Chova Sergio Muñoz Eduardo Araujo-Nepomuceno Antonio Bonillo Antonio Molina-Carballo 《Free radical research》2013,47(9):1035-1040
Objective: To study the evolution of lipid peroxidation, enzymatic antioxidants response, lipid profile and membrane fluidity in erythrocytes from very low birth weight (VLBW) infants during their first 7 days of extra-uterine life.Study design: One hundred and twenty infants were selected and divided in two groups according to their weight and gestational age. Hydroperoxides, fatty-acid profile, fluidity (DPH and TMA-DPH) and catalase, SOD and GPx activities were measured in erythrocytes.Results: VLBW group showed higher concentration of hydroperoxides and lower membrane fluidity during the first 72 h, lower SOD activity during the first 3 h and higher GPx activity during the first 7 days of life. Also, this group showed lower n-3 polyunsaturated fatty-acids percentage with respect to the term group.Conclusion: Erythrocytes from VLBW infants showed higher oxidative damage and lower fluidity in their membranes, at least during the first 3 days of extra-uterine life, which may cause alterations in their functions and flexibility. 相似文献
108.
Raquel Bridi Alexandra Latini César A. Braum Giovanni K. Zorzi Moacir Wajner Eduardo Lissi 《Free radical research》2013,47(1):71-79
Maple syrup urine disease (MSUD) is a metabolic disorder caused by the deficiency of the activity of the mitochondrial enzyme complex branched-chain l-2-keto acid dehydrogenase. The metabolic block results in tissue and body fluid accumulation of the branched-chain amino acids leucine (Leu), isoleucine and valine, as well as of their respective α-keto acids. Neurological sequelae are usually present in MSUD, but the pathophysiologic mechanisms of neurotoxicity are still poorly known. It was previously demonstrated that Leu elicits oxidative stress in rat brain. In the present study we investigated the possible mechanisms involved in Leu-induced oxidative damage. We observed a significant attenuation of Leu-elicited increase of thiobarbituric acid-reactive substances (TBA-RS) measurement when cortical homogenates were incubated in the presence of the free radical scavengers ascorbic acid plus trolox, dithiothreitol, glutathione, and superoxide dismutase, suggesting a probable involvement of superoxide and hydroxyl radicals in this effect. In contrast, the use of Nω-nitro-l-arginine methyl ester or catalase (CAT) did not affect TBA-RS values. We also demonstrated an inhibitory effect of Leu on the activities of the antioxidant enzymes CAT and gluthathione peroxidase, as well as a significant reduction in the membrane-protein thiol content from mitochondrial enriched preparations. Furthermore, dichlorofluorescein levels were increased although not significantly by Leu. Taken together, our present data indicate that an unbalance between free radical formation and inhibition of critical enzyme activities may explain the mechanisms involved in the Leu-induced oxidative damage. 相似文献
109.
110.
Mauro Tambasco Ian Nygren Eric Yorke-Slader J. Eduardo Villarreal-Barajas 《Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB)》2013,29(5):537-544
The authors develop and investigate a user-friendly computational tool (FracMod) to quantify modulation complexity in planned IMRT fields.FracMod comprises a graphical user interface and variogram fractal dimension (FD) analysis tool developed by the authors using MATLAB®, and made freely available at http://www.medphysfiles.com/index.php. FracMod is investigated for its ability to identify overly-modulated dynamic IMRT fields designed for prostatic carcinoma treatments. A set of 5 prostate alone plans and 5 prostate plus pelvic node plans were used to choose FD cut-points that ensure no false positives in distinguishing between moderate and high field modulation. IMRT quality control (QC) was performed on all the treatment fields using Varian® Portal Dosimetry and MapCHECK?. Receiver operating characteristic analysis was used to quantitatively compare the classification performance of FD and the number of monitor units (MUs). The effect of dose rate on the average leaf pair opening (ALPO) and the number of MUs delivered was also investigated.The variogram FD performed better than the number of MUs in identifying overly-modulated fields.FD thresholds >2.15 for prostate alone and >2.20 for prostate plus pelvic nodes correctly identified 75% and 100% of the high modulation fields, respectively, with no false positives. With appropriate cut-points, MapCHECK? identified the most highly modulated IMRT fields, whereas Varian® Portal Dosimetry could not. As expected, ALPO decreases with increasing modulation and increasing dose rate.FracMod is a user-friendly tool that allows one to accurately quantify and identify overly-modulated IMRT fields at the treatment planning stage before they are sent for patient-specific QC. 相似文献