Publications by authors named "CALIXTO S"

For most patients admitted to a hospital, it is a requirement to continuously monitor their vital signs. Among these are the waveforms from ECG and the pulmonary arterial pulse. At present, there are several electronic devices that can measure the arterial pulse waveform.

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Article Synopsis
  • *Chemical analysis has revealed a variety of beneficial compounds, and extracts have demonstrated antibacterial, antifungal, and larvicidal properties.
  • *This study is the first to investigate the bioactive compounds in extracts from L. grown in agroecological conditions, identifying 83 compounds and highlighting the potential of its ethyl acetate partition for therapeutic applications.*
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Antifungal resistance poses a significant challenge to disease management, necessitating the development of novel drugs. Antimicrobial peptides offer potential solutions. This study focused on extraction and characterization of peptides from Adenanthera pavonina seeds with activity against Candida species, Mycobacterium tuberculosis, proteases, and α-amylases.

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This paper describes the use of an optical instrument, the Fabry-Perot interferometer, adapted to measure very low pressures. The interferometer consists of two high-reflectance flat mirrors placed one in front of another. In addition, a metallic chamber contains air or a gas.

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In 2020, humanity experienced one of the most complex situations in history: The COVID-19 pandemic, which caused significant social, economic, and educational consequences. Nevertheless, countries and people generally survived. Why? Resilience and the ability to cope are fundamental elements in human, community, and national survival.

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The use of surface relief structures is increasing in the field of optics. A study of photoinduced relief using dichromated gelatin films with different thickness is described in this paper. Two light sources were used: a laser (λ = 468 nm) and an ultraviolet mercury-metal halide lamp.

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Tuberculosis (TB) remains a serious public health problem and one of the main concern is the emergence of multidrug-resistant and extensively resistant TB. Hyper-reactive patients develop inflammatory necrotic lung lesions that aggravate the pathology and facilitate transmission of mycobacteria. Treatment of severe TB is a major clinical challenge that has few effective solutions and patients face a poor prognosis, years of treatment and different adverse drug reactions.

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Objectives: This study aimed to evaluate endophytic fungi isolated from Tocoyena bullata and Humiria balsamifera plant species for their antimycobacterial and anti-inflammatory activities, focusing on severe pulmonary tuberculosis cases which are often associated with exacerbated inflammation.

Methods: Mycobacterium suspensions were incubated with the samples for 5 days. RAW 264.

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Among non-tuberculous mycobacteria, is one of the most pathogenic, able to cause pulmonary disease indistinguishable from tuberculosis in immunocompetent susceptible adults. The lack of animal models that reproduce human-like lung disease, associated with the necrotic lung pathology, impairs studies of virulence and pathogenicity. In this study, we examined the ability of the C57BL/6 mice, intratracheally infected with highly virulent strains, to produce a chronic infection and necrotic lung pathology.

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Microbial resistance to available drugs is a growing health threat imposing the need for the development of new drugs. The scaffold of plant defensins, including their γ-cores, are particularly good candidates for drug design. This work aimed to improve the antifungal activity of a previous design peptide, named A,,γVuDef (for short DD) against yeasts by altering its biochemical parameters.

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A set of parallel microfluidic channels behaving as a diffraction grating operating in the Raman-Nath regime has been fabricated and studied. The diffraction efficiency of such structure can be tuned by selecting a liquid with a particular refractive index and/or optical anisotropy. Alternatively the optical properties of the liquid can be characterised by measuring the diffraction efficiency and the state of polarization of the diffracted beam.

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Scientific advances have not been enough to combat the growing resistance to antimicrobial medicines. Antimicrobial peptides (AMPs) are effector molecules of the innate immune defense system in plants and could provide an important source of new antimicrobial drugs. The aim of this work was to extract, purify, characterize, and evaluate the antifungal activities present in fractions obtained from Capsicum annum fruits through reversed-phase chromatography.

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We developed two versions of refractometers to measure the refractive index of liquids. One refractometer comprises a glass cell with a surface relief grating on the inner face of one of its walls, while the other one is a microfluidic channel in the form of serpentine that behaves as a grating. Measurements of the liquid refractive index were performed by sensing the first order intensity.

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A phytochemical study of leaves and twigs of resulted in 19 compounds, including five indole alkaloids, ,,-trimethyltryptamine, lyaloside, strictosamide, strictosidine, and 5α-carboxystrictosidine; two flavonolignans, cinchonain Ia and cinchonain Ib; an iridoid, roseoside; a sugar, lawsofructose; a coumarin, scopoletin; a diterpene, phytol; three triterpenes, pomolic acid, spinosic acid, and rotungenic acid; and five steroids, sitosterol, stigmasterol, campesterol, -sitosterol-3---d-glucoside, and -stigmasterol-3---d-glucoside. Some compounds were evaluated for their in vitro activity against and their ability to inhibit NO production by macrophages stimulated by lipopolysaccharide (LPS). The compounds pomolic acid, spinosic acid, strictosidine, and 5α-carboxystrictosidine displayed antimycobacterial activity with minimum inhibitory concentrations ranging from 7.

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The use of electronic devices to measure Relative Humidity (RH) is widespread. However, under certain circumstances, for example when explosive gases are present, a spark-free method should be used. Here we suggest the use of stimuli-responsive materials, like gelatin and interpenetrated polymers, to detect RH with an optical method.

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Because this issue journal is dedicated to Gelatin, here we present a few applications of gelatin in the field of optics. Optics is the science that studies the production, propagation, interaction and detection of light. Various materials sensitive to light (photosensitive) are used for detection of light, such as photomultipliers, CCDs, crystals, two dimensional (2D) materials and more.

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Article Synopsis
  • The search for new leishmaniasis treatments focuses on finding alternatives to current drugs, which have issues like high toxicity and cost.
  • A study explored the effectiveness of specific steroid derivatives from cholesterol and bile acids against the Leishmania parasite, finding that some had promising antileishmanial activity with low toxicity to host cells.
  • The best compound, DOCAD5, showed potential for oral administration and worked by disrupting the parasite's mitochondrial function and cycling, making it a strong candidate for further development.
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Leishmaniases are infectious diseases, caused by protozoa of the Leishmania genus. These drugs present high toxicity, long-term administration, many adverse effects and are expensive, besides the identification of resistant parasites. In this work, the antileishmanial activity of quinoline derivative salts (QDS) was evaluated, as well as the toxicity on mammalian cells and the mechanism of action of the most promising compound.

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Polarimeters are useful instruments that measure concentrations of optically active substances in a given solution. The conventional polarimetric principle consists of measuring the rotation angle of linearly polarized light. Here, we present a novel polarimeter based on the study of interference patterns.

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Leishmaniasis has become a significant public health issue in several countries in the world. New products have been identified to treat against the disease; however, toxicity and/or high cost is a limitation. The present work evaluated the antileishmanial activity of a new naphthoquinone derivate, Flau-A [2-(2,3,4-tri-O-acetyl-6-deoxy-β-L-galactopyranosyloxy)-1,4-naphthoquinone], against promastigote and amastigote-like stages of Leishmania amazonensis and L.

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Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis (Mtb) that in most cases induces irreversible necrosis of lung tissue as a result of excessive inflammatory reactions. The murine model of TB in resistant C57BL/6 mice infected with reference Mtb strains is widely used in TB studies; however, these mice do not show a necrotic pathology, which restricts their use in studies of irreversible tissue damage. Recently, we demonstrated that necrotic lung lesions could be induced in the C57BL/6 mice by highly virulent Mtb strains belonging to the modern Beijing sublineage.

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This paper describes the design, fabrication, and testing of two hollow prisms. One is a prism with a grating glued to its hypotenuse. This ensemble, prism + grating, is called a grism.

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The Mueller matrices associated to six homemade special index-guiding microstructured fibers are determined at a transmission wavelength of 1550 nm. Diattenuation, polarizance, and polarization-dependent loss, among other polarimetric parameters, are determined from the Mueller matrix associated to a 2 m length of each fiber studied here. Results show that the fiber fabrication parameters have a clear effect on the output degree of polarization (DoP), providing an inverse relationship between the DoP output and the relative hole diameter, the d/Λ value.

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