28 research outputs found

    Antibacterial and antioxidant activities of Licania tomentosa (Benth.) fritsch (crhysobalanaceae)

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    This work describes the chemical composition, and evaluates the antimicrobial and antioxidant activities of a hydroalcoholic extract from the leaves of the Licania tomentosa. Gram positive and negative bacterial strains were used in this work. Examination of the phytochemical composition of L. tomentosa revealed the presence of secondary metabolites such as tannins, flavonoids, saponins, alkaloids, steroids and triterpenoids. An antibacterial assay pointed out that the extract had a lower minimal inhibitory concentration (MIC - 32 μg/mL) towards Staphylococcus aureus (ATCC12692). The extract also presented antibacterial activity against other assayed bacteria, with the MIC varying between 64 and 512 μg/ mL. Our findings reveal that the extract presented an antioxidative capacity lower than that of BHT at the same concentration, used as positive control. Our results suggest that the levels and combinations between the secondary metabolites of this plant should be investigated to explain the demonstrated antibacterial activity

    Design Specifications for an Auxiliary Incision Retractor in Dacryocystorhinostomy Surgeries

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    It is presented the design specifications for a Retractor Robotic System (RRS) based on the surgical necessities in the incisions procedure for a dacryocystorhinostomy. The specifications are conformed by a mathematical model, the experimental data measured, a modular flexible architecture, energy supplier system, the mechanical group, and the safety system. The specifications suggest that the use of flexible polymeric materials for the RRS provide a mayor adaptability of the system with the biological tissue; so a pneumatic actuator could be a suitable option.This research was funded by CONACYT (Consejo Nacional de Ciencia y Tecnología) Grant No. 86356

    UPLC-MS-ESI-QTOF analysis and antifungal activity of the spondias tuberosa arruda leaf and root hydroalcoholic extracts

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    The aim of this study was to identify and evaluate the chemical compositions and effects of the S. tuberosa leaf and root hydroalcoholic extracts (HELST and HERST) against different strains of Candida. Chemical analysis was performed by Ultra-Performance Liquid Chromatography Coupled to Quadrupole/Time of Flight System (UPLC-MS-ESI-QTOF). The Inhibitory Concentration of 50% of the growth (IC50) as well as the intrinsic and combined action of the extracts with the antifungal fluconazole (FCZ) were determined by the microdilution method while the minimum fungicidal concentrations (MFCs) and the effect on fungal morphological transitions were analyzed by subculture and in humid chambers, respectively. From the preliminary phytochemical analysis, the phenols and flavonoids were the most abundant. The intrinsic IC50 values for HELST ranged from 5716.3 to 7805.8 \ub5g/mL and from 6175.4 to 51070.9 \ub5g/mL for the HERST, whereas the combination of the extracts with fluconazole presented IC50 values from 2.65 to 278.41 \ub5g/mL. The MFC of the extracts, individually, for all the tested strains was 6516384 \ub5g/mL. When fluconazole was combined with each extract, the MFC against CA URM 5974 was reduced (HELST: 2048 and HERST: 4096 \ub5g/mL). Synergism was observed against standard C. albicans (CA) and C. tropicalis (CT) strains and with the root extract against the CT isolate. The leaf extract inhibited the morphological transition of all strains while the root extract inhibited only CT strains

    Photoinduced antibacterial activity of the essential oils from Eugenia brasiliensis lam and Piper mosenii C. DC. by blue led light

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    The objective of this work was to evaluate the phytochemical composition and the antibacterial and antibiotic-modulating activities of the essential oils of Eugenia brasiliensis Lam (OEEb) and Piper mosenii C. DC (OEPm) singly or in association with blue LED (Light-emitting diode) light. The antibacterial and antibiotic-modulatory activities of the essential oils on the activity of aminoglycosides were evaluated to determine the minimum inhibitory concentration (MIC, \u3bcg/mL) in the presence or absence of exposure to blue LED light. The chemical analysis showed \u3b1-pinene and bicyclogermacrene as major constituents of OEPm, whereas \u3b1-muurolol was the main compound of OEEb. Both OEEb and OEPm showed MIC 65 512 \u3bcg/mL against the strains under study. However, the association of these oils with the blue LED light enhanced the action of the aminoglycosides amikacin and gentamicin. In conclusion, the association of aminoglycosides with the blue LED light and essential oils was effective against resistant bacteria

    Search for dark mesons decaying to top and bottom quarks in proton-proton collisions at √s = 13 TeV with the ATLAS detector

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    A search for dark mesons originating from strongly-coupled, SU(2) dark favor symmetry conserving models and decaying gaugephobically to pure Standard Model final states containing top and bottom quarks is presented. The search targets fully hadronic final states and final states with exactly one electron or muon and multiple jets. The analyzed data sample corresponds to an integrated luminosity of 140 fb−1 of proton-proton collisions collected at √s = 13 TeV with the ATLAS detector at the Large Hadron Collider. No significant excess over the Standard Model background expectation is observed and the results are used to set the first direct constraints on this type of model. The two-dimensional signal space of dark pion masses mπD and dark rho-meson masses mρD is scanned. For mπD /mρD = 0.45, dark pions with masses mπD < 940 GeV are excluded at the 95% CL, while for mπD /mρD = 0.25 masses mπD < 740 GeV are excluded

    Combination of searches for Higgs boson decays into a photon and a massless dark photon using pp collisions at √s = 13 TeV with the ATLAS detector

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    A combination of searches for Higgs boson decays into a visible photon and a massless dark photon (H → γγd) is presented using 139 fb−1 of proton-proton collision data at a centre-of-mass energy of √s = 13 TeV recorded by the ATLAS detector at the Large Hadron Collider. The observed (expected) 95% confidence level upper limit on the Standard Model Higgs boson decay branching ratio is determined to be B(H → γγd) < 1.3% (1.5)%. The search is also sensitive to higher-mass Higgs bosons decaying into the same final state. The observed (expected) 95% confidence level limit on the cross-section times branching ratio ranges from 16 fb (20 fb) for mH = 400 GeV to 1.0 fb (1.5 fb) for mH = 3 TeV. Results are also interpreted in the context of a minimal simplified model

    Phytochemistry and Biological Activities of Amburana cearensis (Allemão) ACSm

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    Amburana cearensis (Allemão) ACSm. belongs to the Fabaceae family and occurs in the Brazilian semiarid, Argentina, Paraguay, Bolivia, and Peru. Numerous studies that portray its ethnobotany, use in popular medicine, chemical composition, and biological activities exist in the literature. This review aimed to provide an overview of the chemical composition, ethnopharmacology, and biological activities associated with A. cearensis and its isolated constituents. Information was collected from internet searches in the Scopus, Medline, PubMed, Google Scholar, and ScienceDirect databases were performed covering publications from 1997�2020. An ethnopharmacological literature analysis revealed that A. cearensis is used to treat a wide range of respiratory disorders in addition to intestinal, circulatory, and inflammatory problems. Coumarins, flavonoids, phenolic glycosides, phenolic acids, phenylpropanoid derivatives, and triterpenoids, among others, have been reported as active compounds, with High-Performance Liquid Chromatography (HPLC) being the main analytical technique used. The A. cearensis extracts and compounds presented several biological activities, including antimicrobial, antinociceptive, anti-inflammatory, antioxidant, neuroprotective, and myorelaxant activities, among others. This review provides a useful bibliography for future investigations and A. cearensis applications; however, future studies should focus on its toxic effects and the mechanisms of action of its extracts and isolated constituents to guide clinical applications. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

    Antiviral therapeutic potential of curcumin: An update

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    The treatment of viral disease has become a medical challenge because of the increasing incidence and prevalence of human viral pathogens, as well as the lack of viable treatment alternatives, including plant-derived strategies. This review attempts to investigate the trends of research on in vitro antiviral effects of curcumin against different classes of human viral pathogens worldwide. Various electronic databases, including PubMed, Scopus, Web of Science, and Google Scholar were searched for published English articles evaluating the anti-viral activity of curcumin. Data were then extracted and analyzed. The forty-three studies (published from 1993 to 2020) that were identified contain data for 24 different viruses. The 50 cytotoxic concentration (CC50), 50 effective/inhibitory concentration (EC50/IC50), and stimulation index (SI) parameters showed that curcumin had antiviral activity against viruses causing diseases in humans. Data presented in this review highlight the potential antiviral applications of curcumin and open new avenues for further experiments on the clinical applications of curcumin and its derivatives. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
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