Despite heightened awareness of the detrimental impact of hate speech on social media platforms on affected communities and public discourse, there is little consensus on approaches to mitigate it. While content moderation-either by governments or social media companies-can curb online hostility, such policies may suppress valuable as well as illicit speech and might disperse rather than reduce hate speech. As an alternative strategy, an increasing number of international and nongovernmental organizations (I/NGOs) are employing counterspeech to confront and reduce online hate speech.
View Article and Find Full Text PDFTo investigate the degree of conversion (DC), Martens hardness (HM), elastic indentation modulus (E), and flexural strength (FS) of veneering resin composites (SR Nexco Paste (NP), Ceramage Incisal (CI), Gradia Plus (GP); n=60/group) cured with different polymerization devices (bre.Lux Power Unit, Labolight DUO, Otoflash G171, LC-3DPrint Box, PCU LED; n=12/subgroup) after storage. Otoflash G171 and Labolight DUO showed increased DC/HM/E.
View Article and Find Full Text PDFThe variable configuration of Raman spectroscopic platforms is one of the major obstacles in establishing Raman spectroscopy as a valuable physicochemical method within real-world scenarios such as clinical diagnostics. For such real world applications like diagnostic classification, the models should ideally be usable to predict data from different setups. Whether it is done by training a rugged model with data from many setups or by a primary-replica strategy where models are developed on a 'primary' setup and the test data are generated on 'replicate' setups, this is only possible if the Raman spectra from different setups are consistent, reproducible, and comparable.
View Article and Find Full Text PDFBenthic grazing strongly controls periphyton biomass. The question therefore arises whether benthic grazing could be used as a tool to reduce excessive growth of periphyton in nutrient-enriched rivers. Although benthic invertebrate grazers reduce the growth of periphyton, this is highly context dependent.
View Article and Find Full Text PDFThe combination of scanning probe microscopy and Raman spectroscopy enables chemical characterization of surfaces at highest spatial resolution. This so-called tip-enhanced Raman scattering (TERS) can be employed for a variety of samples where a label-free characterization or identification of constituents on the nanometer scale is pursued. Present TERS setup geometries are always a compromise for specific dedicated applications and show different advantages and disadvantages: Transmission back-reflection setups, when using immersion objectives with a high numerical aperture, intrinsically provide the highest collection efficiency but cannot be applied for opaque samples.
View Article and Find Full Text PDFThe genotoxicity of bloom head (BHE) and leaf (LE) extracts from artichoke (Cynara scolymus L.), and their ability to modulate the mutagenicity and recombinogenicity of two alkylating agents (ethyl methanesulfonate - EMS and mitomycin C - MMC) and the intercalating agent bleomycin (BLM), were examined using the somatic mutation and recombination test (SMART) in Drosophila melanogaster. Neither the mutagenicity nor the recombinogenicity of BLM or MMC was modified by co- or post-treatment with BHE or LE.
View Article and Find Full Text PDFArrabidaea chica Verlot (Bignoniaceae) is an important folk medicine plant native to the Amazon region and used to treat anemia, hemorrhage, inflammation, intestinal colic, hepatitis, and skin affections. Although studies showed its therapeutic properties, little knowledge regarding genotoxic properties of this plant is available. The aim of this study was to determine the potential mutagenic and genotoxic/antigenotoxic effects of an A.
View Article and Find Full Text PDFUnlabelled: The Cynara scolymus (artichoke) is widely consumed as tea or food and shows important therapeutic properties. However, few studies have assessed the possible toxic effects of artichoke extracts. This study evaluates genotoxic and mutagenic activities of artichoke leaf aqueous extract in mice using the comet assay and the micronucleus test.
View Article and Find Full Text PDFMalpighia glabra L, popularly known as acerola, is considered a functional fruit and therefore is taken to prevent disease or as adjuvant to treatment strategies, since the fruit is an undeniable source of vitamin C, carotenoids, and flavonoids. Acerola is a natural source of vitamin C, flavonoids, and carotenoids. Its chemical composition is affected by genetic uniformity of the orchards and environmental factors.
View Article and Find Full Text PDFCroton cajucara Benth is a plant found in Amazonia, Brazil and the bark and leaf infusion of this plant have been popularly used to treat diabetes and hepatic disorders. The present study was designed to evaluate the oxidative stress as well as the therapeutic effect of Croton cajucara Benth (1.5 mL of the C.
View Article and Find Full Text PDFBenign prostatic hyperplasia (BPH) is the most common tumor in men over 40 years of age. Acute urinary retention (AUR) is regarded as the most serious hazard of untreated BPH. α-Blockers, such as doxazosin mesylate, and 5-α reductase inhibitors, such as finasteride, are frequently used because they decrease both AUR and the need for BPH-related surgery.
View Article and Find Full Text PDFGenotoxic and antigenotoxic effects of acerola fruit at two stages of ripeness were investigated using mice blood cells. The results show that no ripeness stage of acerola extracts presented any genotoxic potential to damage DNA (Comet assay) or cytotoxicity (MTT assay). When antigenotoxic activity was analyzed, unripe fruit presented higher DNA protection than ripe fruit (red color) extract.
View Article and Find Full Text PDFContext: Copaiba oil is an oleoresin made up of resin acids and volatile compounds, and it is obtained by tapping the trunks of trees that are members of the Copaifera L. (Leguminoseae) genus and are found in tropical parts of Latin America.
Objective: This study analyzed the chemical composition of Copaifera multijuga Hayne oil and conducted preclinical trials to investigate anti-inflammatory effects and any action it may have on the central nervous system (CNS) of rats.
The present study was designed to evaluate the oxidative stress as well as the therapeutic effect of Agaricus blazei Muril (A. Blazei) in rats with streptozotocin-induced diabetes. We used 25 Wistar rats, and DM was induced by injecting streptozotocin (70 mg/Kg i.
View Article and Find Full Text PDFA first vibrational mapping on the nanometer scale was performed on a protein (streptavidin) labelled supported phospholipid film by means of tip-enhanced Raman spectroscopy (TERS). For this purpose a TERS spectral map was measured on the biomembrane model, using a step size far below the diffraction limit. Considering the model composition, spectra were classified as either typical for lipids, proteins or both simultaneously, in a qualitative manner.
View Article and Find Full Text PDFEthnopharmacological Relevance: Baccharis trimera (Less.) (Asteraceae) is a native plant from Brazil. Also known as "carqueja", it is popularly used to treat liver diseases, diabetes, as well as digestive disorders, mainly by women with lower socioeconomic status.
View Article and Find Full Text PDFThe photoprotective effect of the methanolic extracts of three Antarctic plant species - Deschampsia antarctica Desv., Colobanthus quitensis (Kunth) Bartl., and Polytrichum juniperinum Hedw.
View Article and Find Full Text PDFRecent insights into the allosteric control of oxygen binding in the extracellular hemoglobin (Hb) of the tadpole shrimp Triops cancriformis raised the question about the physico-chemical properties of the protein's native environment. This study determined the cationic composition and acid-base state of the animal's extracellular fluid. The physiological concentrations of potential cationic effectors (calcium, magnesium) were more than one order of magnitude below the level effective to increase Hb oxygen affinity.
View Article and Find Full Text PDFThe goal of this paper is to optimize the pressurized liquid extraction (PLE) of vitamin E from grape seed oil from residues of the wine industry. For this purpose an experimental planning to optimize the extraction of Brazilian grape seed oil by means of PLE with hexane as solvent was applied and the results are compared with conventional methods (Soxhlet and mechanical press extraction). Vitamin E was separated and analyzed using HPLC with UV detection.
View Article and Find Full Text PDFPsychollatine is a monoterpene indole alkaloid produced and accumulated by Psychotria umbellata Vell. (Rubiaceae) leaves in relatively high amounts (approximately 3% of the dry weight). The alkaloid has been shown to display opioid-like analgesic, anxiolytic, antidepressive and antipsychotic activities in rodents.
View Article and Find Full Text PDFFreeze-dried extracts from Camellia sinensis var. assamica IAC-259 cultivar named Brazilian green tea were prepared by hot water and ultrasound-assisted extractions using leaves harvested in spring and summer. Their caffeine and catechin contents were measured by high performance liquid chromatography-diode array detector.
View Article and Find Full Text PDFToxicol In Vitro
December 2007
Plants of the genus Hibiscus thrives produce a diversity of molecules with bioactive properties. In a previous study of Hibiscus tiliaceus L. methanolic extract (HME) using bacteria and yeast, as test media, it has been shown that HME strongly inhibited the mutagenic action of H(2)O(2) or tert-butyl-hydroperoxide (t-BHP).
View Article and Find Full Text PDFThe beta-carboline alkaloids found in medical plants and in a variety of foods, beverages and cigarette smoke have a range of action in various biological systems. In vitro studies have demonstrated that these alkaloids can act as scavengers of reactive oxygen species. In this paper, we report the in vivo antioxidative properties of the aromatic (harmane, harmine, harmol) and dihydro-beta-carbolines (harmaline and harmalol) studied by using Saccharomyces cerevisiae strains proficient and deficient in antioxidant defenses.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
February 2005
Bombesin (BN) and its mammalian equivalent, gastrin-releasing peptide (GRP), stimulate cell proliferation and are involved in the pathogenesis of several types of human cancer. BN/GRP and their receptors were shown to be critical for the growth of various human malignancies, such as small-cell lung, prostate, ovary, stomach and breast cancers in the human tumor xenograft model. In the present study, a fast, sensitive, robust method was developed for the determination and quantification of a BN/GRP receptor antagonist RC-3095 (D-Tpi-Gln-Trp-Ala-Val-Gly-His-Leupsi(CH2NH)Leu-NH2), in human plasma by liquid chromatography coupled with tandem mass spectrometry.
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