7,537 results on '"Luis A. García"'
Search Results
2. Multiple sclerosis in Central America and Caribbean countries: frequency and clinical characterization of an emergent disease
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Fernando Gracia, Deyanira A. Ramírez Navarro, Nicia E. Ramírez Sánchez, Roberto Weiser, Alexander Parajeles-Vindas, Ligia I. Portillo Rivera, Ericka López Torres, Luis A. García Valle, Alfredo Sanabria-Castro, César Abdón López, Pahola Araujo, Maria J. Ayerdis Zamora, Andrea Balmaceda-Meza, Aron Benzadon Cohen, Awilda Candelario Cueto, Diego Castillo, Romy Castro-Escobar, Karla Z. Corea Urbina, Anyeri de Peña Rivas, Octavio Duarte Sotelo, Temís Enamorado Claros, José L. Giroud Benítez, Karla Gracia, Mario Larreategui, Jorge A. Martínez Cerrato, Josmarlin P. Medina Báez, Carlos E. Menjivar Samayoa, Gustavo Miranda-Loria, Priscilla Monterrey-Alvarez, Lilliam A. Morales Arguello, Michelle Ortiz, Carlos D. Pérez Baldioceda, Lizeth Pinilla Aguilar, Luis C. Rodríguez Salinas, Virginia Rodríguez-Moreno, Sebastián Rojas-Chaves, Norbel Román-Garita, Biany Santos Pujols, Carlos Valderrama, Ivonne Van Sijtveld, Indhira Zabala Angeles, Victor M. Rivera, and Blas Armien
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multiple sclerosis ,incidence ,prevalence ,Mestizos ,Central America ,Caribbean ,Infectious and parasitic diseases ,RC109-216 - Abstract
BackgroundMultiple Sclerosis (MS) is a common neurological disease among white populations of European origin. Frequencies among Latin Americans continue to be studied, however, epidemiologic, and clinical characterization studies lack from Central American and Caribbean countries. Ethnicity in these countries is uniformly similar with a prevalent Mestizo population.Methods and resultsData from January 2014 to December 2019 from Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Dominican Republic, and Aruba on demographic, clinical, MRI and phenotypic traits were determined in coordinated studies: ENHANCE, a population-based, retrospective, observational study on incidence and clinical characteristics, and from the subgroup with MS national registries (Aruba, Dominican Republic, Honduras, and Panama), data on prevalence, phenotypes and demographics. Expanded Disability Status Scale (EDSS), and therapeutic schemes were included. ENHANCE data from 758 patients disclosed 79.8% of Mestizo ethnicity; 72.4% female; median age at onset 31.0 years and 33.2 at diagnosis. The highest incidence rate was from Aruba, 2.3–3.5 × 100,000 inhabitants, and the lowest, 0.07–0.15 × 100,000, from Honduras. Crude prevalence rates per 100,000 inhabitants fluctuated from 27.3 (Aruba) to 1.0 (Honduras). Relapsing MS accounted for 87.4% of cases; EDSS
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- 2024
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3. Modeling and optimization of microwave-assisted extraction of total phenolics content from mango (Mangifera indica) peel using response surface methodology (RSM) and artificial neural networks (ANN)
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David Ramírez-Brewer, Somaris E. Quintana, and Luis A. García-Zapateiro
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Mango peel ,Natural extracts ,Microwave-assisted extraction ,Artificial neural network ,Response surface methodology ,Nutrition. Foods and food supply ,TX341-641 ,Food processing and manufacture ,TP368-456 - Abstract
Mango (Mangifera indica) is a fruit highly consumed for its flavor and nutrient content. The mango peel is rich in compounds with biological functionality, such as antioxidant activity among others. The influence of microwave-assisted extraction variables on total phenol compounds (TPC) and antioxidant activity (TEAC) of natural extracts obtained from mango peel var. Tommy and Sugar were studied using a response surface methodology (RSM) and Artificial Neural Networks (ANN). TPC of mango peel extract var. Tommy was significantly influenced by time extraction (X1), solvent/plant ratio (X2) and concentration of ethanol (X3) and while mango peel extract var. Sugar was influenced by X2. TEAC by ABTS was significantly influenced by X3. Maximum of TPC (121.3 mg GAE / g of extract) and TEAC (1185.9 μmol Trolox/g extract) for mango peel extract var. Tommy were obtained at X1=23.9s, X2=12.6mL/gand X3=63.2%, and for mango peel extract var. Sugar, the maximum content of TPC (224.86 mg GAE/g extract) and TEAC (2117.7 μmol Trolox/g extract) were obtained at X1=40s, X2=10mL/g and X3=74.9%. The ANN model presented a higher predictive capacity than the RSM (RANN2>RRSM2,RMSEANN
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- 2024
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4. Exploring Heavy Metal and Metalloid Exposure in Children: A Pilot Biomonitoring Study near a Sugarcane Mill
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Oliver Mendoza-Cano, Agustin Lugo-Radillo, Mónica Ríos-Silva, Irma Elizabeth Gonzalez-Curiel, Jaime Alberto Bricio-Barrios, Arlette A. Camacho-delaCruz, María Fernanda Romo-García, Herguin Benjamín Cuevas-Arellano, Ana Luz Quintanilla-Montoya, Ramón Solano-Barajas, Juan Manuel Uribe-Ramos, Luis A. García-Solórzano, Ángel Gabriel Hilerio-López, Alma Alejandra Solano-Mendoza, Rogelio Danis-Romero, and Efrén Murillo-Zamora
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child ,metals ,heavy ,metalloids ,environmental exposure ,Chemical technology ,TP1-1185 - Abstract
Sugarcane production has been linked to the release of heavy metals and metalloids (HM/MTs) into the environment, raising concerns about potential health risks. This study aimed to assess the levels of 19 HM/MTs in children living near a sugarcane mill through a pilot biomonitoring investigation. We investigated sex-related differences in these element levels and their correlations. A cross-sectional study was conducted, analyzing data from 20 children in the latter part of 2023. Spearman correlation coefficients with 95% confidence intervals (CIs) were used to assess the relationships between urinary HM/MT levels. Detectable levels of 17 out of the 19 HM/MTs were found across the entire study sample, with arsenic and copper detectable in 95% of the children. Titanium exhibited higher levels in boys compared to girls (p = 0.017). We identified 56 statistically significant correlations, with 51 of them being positive, while the remaining coefficients indicated negative relationships. This study characterized HM/MT levels in school-aged children residing near a sugarcane mill through a pilot biomonitoring investigation. Further research employing larger sample sizes and longitudinal assessments would enhance our understanding of the dynamics and health impacts of HM/MT exposure in this vulnerable population.
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- 2024
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5. A new species of spiny-backed tree frog, genus Osteocephalus (Anura, Hylidae), from the Yanachaga Chemillén National Park in central Peru
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Pablo J. Venegas, Luis A. García-Ayachi, Eduardo Toral, José Malqui, and Santiago R. Ron
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Evolution ,QH359-425 ,Life ,QH501-531 - Abstract
We describe a new species of Osteocephalus Fitzinger, 1843 using morphological traits of adult frogs and its larvae, as well as molecular evidence. The new species occurs in the premontane forest of the Cordillera del Yanachaga in the Andes of central Peru, at elevations between 1000 and 1150 m a.s.l. It belongs to the Osteocephalus mimeticus species group and is the sister species of O. mimeticus. It is most similar to three species with predominantly dark irises, tuberculate dorsal skin, and brown dorsal coloration: O. festae Peracca, 1904, O. mimeticus Melin, 1941, and O. verruciger Werner, 1901. Of these three species, the most similar is O. mimeticus. However, the new species can be easily distinguished from O. mimeticus by having a cream or creamy-tan venter with a well-defined pattern of brown chocolate blotches and flecks (venter cream, tan, or brown without marks in O. mimeticus). The tadpoles of O. vasquezi sp. nov. are strikingly different from the tadpoles of O. mimeticus by having a larger oral disk with nine lower labial tooth rows (only six in O. mimeticus). Tadpoles of the new species and those of O. festae are unique among Osteocephalus by belonging to the suctorial ecomorphological guild as shown by their large oral disks. Our time tree suggest that the new species diverged from its sister species at the beginning of the Pleistocene, ~2.5 million years ago.
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- 2023
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6. A New Species of Terrestrial-Breeding Frog, Genus Pristimantis (Anura: Strabomantidae), from the Peruvian Yungas of Central Peru
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Pablo J. Venegas, Luis A. García-Ayachi, Axel Marchelie, Jesús R. Ormeño, and Alessandro Catenazzi
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advertisement call ,new species ,Pampa Hermosa River ,Pristimantis albertus ,taxonomy ,Biology (General) ,QH301-705.5 - Abstract
We describe a new species of terrestrial-breeding frog of the genus Pristimantis from the Peruvian Yungas ecoregion of central Peru, Junin Department. The description is based on the observation of morphological features, color patterns of fourteen specimens, bioacoustic traits of the advertisement calls, and a phylogenetic analysis using a sequence fragment of 16S rRNA. The new species is mainly characterized by having a rounded or truncate snout in dorsal view, presence of dorsolateral folds, tympanic membrane and annulus distinct, absence of flash marks on the hidden surfaces of flanks and hindlimbs, and a small size (maximum SVL 15.6 mm in males and 19.3 mm in females). We provide diagnostic traits to differentiate the new species from phylogenetically close relatives, as well as morphologically similar and sympatric species of Pristimantis.
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- 2023
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7. Los más antiguos orígenes de nuestra Monarquía española. Mito, leyenda y realidad
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Luis A. García Moreno
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monarquía ,instituciones ,constitución ,mito ,History (General) and history of Europe - Abstract
En este artículo abordamos el origen de la monarquía española. Así pues, la monarquía que había propiciado los éxitos de Pelayo y de los primeros principes astures tenía mucho más de autóctono y de imitación franca que de auténtica continuidad, y menos todavía restauración, goda. Eso sería cosa de más adelante en el terreno ideológico, aunque de una enorme fuerza al convertirse en el auténtico “mito-motor” de la etnia, posterior nación, hispana.
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- 2023
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8. Rising from the ashes: A new treefrog (Anura, Hylidae, Scinax) from a wildfire-threatened area in the Amazon lowlands of central Peru
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Germán Chávez, Wilmar Aznaran, Luis A. García-Ayachi, and Alessandro Catenazzi
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Evolution ,QH359-425 ,Life ,QH501-531 - Abstract
We describe a new species of tree frog from the middle Ucayali River, Peru. Scinax pyroinguinis sp. nov. is known from two males found in a patch of Amazon rainforest at 160 masl. Externally, the new species is similar to those in the Scinax rostratus group but it differs from all members by having a rounded head from dorsal view without proboscis or pointed tubercle on the tip of the snout, large conical tubercles on upper eyelids and heels, and bright orange blotches and spots on groins, posterior surface of thighs, and shanks. Genetic analysis supports our morphological study and confirms S. pyroinguinis sp nov as a new species, being tentatively the most basal member of the S. rostratus group. The new species is only known from the type locality that is currently threatened by habitat loss caused by wildfires.
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- 2023
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9. A new species of Microteiid Lizard (Gymnophthalmidae, Cercosaurini, Selvasaura) from a remote area in the Peruvian Andes
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Germán Chávez, Luis A. García-Ayachi, and Alessandro Catenazzi
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Evolution ,QH359-425 ,Life ,QH501-531 - Abstract
We describe a new species of Selvasaura lizard from the western slopes of the eastern Andes of central Peru. Among other characters, the new species differs from congeners in having keeled dorsal scales and more transverse rows of scales on dorsum. We present a phylogeny as additional evidence supporting delimitation of the new species.
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- 2023
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10. A new species of frog (Terrarana, Strabomantidae, Phrynopus) from the Peruvian Andean Grasslands
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Germán Chávez, Luis A. García-Ayachi, and Alessandro Catenazzi
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Evolution ,QH359-425 ,Life ,QH501-531 - Abstract
We describe a new terrestrial frog from the puna grasslands adjacent to the Mantaro dry valley in southern Peru. Phrynopus apumantarum sp. nov. is similar in appearence to P. bufoides but is differentiable by lacking discoidal fold and enlarged warts on dorsum, lacking a prominent post ocular fold and having canthal and post ocular stripe. Lastly, we propose to place the new species under the Vulnerable (VU) category of the IUCN Red List, due its small distribution and habitat loss recorded at the type locality.
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- 2023
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11. Use of Residual Malt from an Artisanal Beer Brewing Process in the Biosynthesis of Silver Nanoparticles Mediated by Nucleating and Structure-Directing Agents
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César A. Dueñas-Bolaños, Margarita Cid-Hernández, Gilberto Velázquez-Juárez, Luis A. García-Casillas, Luis J. González-Ortiz, María Judith Sánchez-Peña, Azucena Herrera-González, Oscar Guillermo Zúñiga-González, and Edgar J. López-Naranjo
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biosynthesis ,silver nanoparticles ,malt extract ,morphological change ,green chemistry ,Organic chemistry ,QD241-441 - Abstract
Biosynthesized silver nanoparticles (AgNPs) are widely used in varied applications, which are morphology dependent. Consequently, a morphology-controlled synthesis is mandatory. Although there are several studies focused on the plant extract-based biosynthesis of metallic nanoparticles, the use of extracts obtained from agro-wastes is scant. Furthermore, information regarding morphology modification through the use of additional agents is even more scarce. Thus, in this study, AgNPs were synthesized using a malt extract (ME) obtained from an artisanal beer brewing process residue. Additionally, sodium chloride (NaCl), gum arabic (GA), and talc (T) were used in an attempt to modify the morphology of AgNPs. XRD, DLS, SEM, and TEM results demonstrate that stable AgNPs of different sizes and shapes were synthesized. FTIR, HPLC analysis, and the quantification of total proteins, free amino acids, reducing sugars, and total polyphenols before and after AgNPs synthesis showed that ME biomolecules allowed them to act as a source of reducing and stabilizing agents. Therefore, this study provides evidence that ME can be successfully used to biosynthesize AgNPs. Additionally, the antibacterial activity of AgNPs against Gram-negative and Gram-positive bacteria was evaluated. Results indicate that AgNPs show a higher antibacterial activity against Gram-positive bacteria.
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- 2024
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12. Quantitative Proteomics Reveal That CB2R Agonist JWH-133 Downregulates NF-κB Activation, Oxidative Stress, and Lysosomal Exocytosis from HIV-Infected Macrophages
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Lester J. Rosario-Rodríguez, Yadira M. Cantres-Rosario, Kelvin Carrasquillo-Carrión, Ana E. Rodríguez-De Jesús, Luz J. Cartagena-Isern, Luis A. García-Requena, Abiel Roche-Lima, and Loyda M. Meléndez
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CATB ,HIV ,MDM ,CB2R ,NF-κB ,Nrf2 ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
HIV-associated neurocognitive disorders (HAND) affect 15–55% of HIV-positive patients and effective therapies are unavailable. HIV-infected monocyte-derived macrophages (MDM) invade the brain of these individuals, promoting neurotoxicity. We demonstrated an increased expression of cathepsin B (CATB), a lysosomal protease, in monocytes and post-mortem brain tissues of women with HAND. Increased CATB release from HIV-infected MDM leads to neurotoxicity, and their secretion is associated with NF-κB activation, oxidative stress, and lysosomal exocytosis. Cannabinoid receptor 2 (CB2R) agonist, JWH-133, decreases HIV-1 replication, CATB secretion, and neurotoxicity from HIV-infected MDM, but the mechanisms are not entirely understood. We hypothesized that HIV-1 infection upregulates the expression of proteins associated with oxidative stress and that a CB2R agonist could reverse these effects. MDM were isolated from healthy women donors (n = 3), infected with HIV-1ADA, and treated with JWH-133. After 13 days post-infection, cell lysates were labeled by Tandem Mass Tag (TMT) and analyzed by LC/MS/MS quantitative proteomics bioinformatics. While HIV-1 infection upregulated CATB, NF-κB signaling, Nrf2-mediated oxidative stress response, and lysosomal exocytosis, JWH-133 treatment downregulated the expression of the proteins involved in these pathways. Our results suggest that JWH-133 is a potential alternative therapy against HIV-induced neurotoxicity and warrant in vivo studies to test its potential against HAND.
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- 2024
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13. Applicability of the Cox–Merz Relationship for Mayonnaise Enriched with Natural Extracts
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Somaris E. Quintana, Maria Zuñiga-Navarro, David Ramirez-Brewer, and Luis A. García-Zapateiro
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mayonnaise ,natural extracts ,viscoelastic properties ,rheology ,Cox–Merz rule ,Thermodynamics ,QC310.15-319 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
The Cox and Merz rules are empirical correlations between the apparent viscosity of polymers with the effect of shear rate and the complex dynamic viscosity with the effect of frequency. In this study, the rheological properties of mayonnaise-type emulsions enriched with Averrhoa carambola extracts were investigated using small-amplitude oscillatory shear (SAOS) and steady shear flow. The results showed that the shear-thinning behavior of the samples was non-Newtonian with yield stress and had time-dependent characteristics, as evidenced by curves from non-oscillatory measurements. It was observed that the experimental data on the complex and apparent viscosity of the samples obeyed the Cox–Merz rule.
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- 2023
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14. Yogurt Enriched with Mango Peel Extracts (Mangifera indica) in Chitosan–Xanthan Gum Dispersions: Physicochemical, Rheological, Stability, and Antioxidant Activity
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Santander E. Lastra-Ripoll, Somaris E. Quintana, and Luis A. García-Zapateiro
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antioxidant activity ,bioactive compounds ,rheological properties ,yield stress ,yogurt ,Thermodynamics ,QC310.15-319 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
Different strategies have been developed to incorporate bioactive compounds into food products to improve their biological activity against degradation effects. The aim of this study was to develop natural yogurt enriched with mango (Mangifera indica) peel extracts (MPEs) in chitosan–xanthan gum dispersions and to evaluate their physicochemical, rheological, and antioxidant activity. A hydroethanolic extract of mango peel was obtained, with a yield of 33.24 ± 1.27%, a total content of phenolic compounds of 305.04 ± 10.70 mg GAE/g, and an antioxidant activity of 1470.41 ± 59.75 μMol Trolox/g. The encapsulation of the extracts was achieved using a chitosan–xanthan gum dispersion, resulting in the rheological characteristic of a strong gel. The incorporation of dispersions into yogurt did not modify the physicochemical properties and increased their bioactive properties. The rheological properties show samples with double yield points and a decrease in viscoelastic parameters. These results show dispersions as a strategy to incorporate bioactive compounds into dairy products, preserve the physicochemical and rheological properties of yogurt, and improve their biological activities (such as antioxidant activity) and activities related to the compounds found in the MPE.
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- 2023
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15. Investigating the Water Relations in Aqueous Extract Powders of Mango (Mangifera indica) Peel and Seed Waste for Their Use in Food Matrices as a Value-Added By-Product
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Ronald Marsiglia-Fuentes, Amparo Chiralt, and Luis A. García-Zapateiro
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mango (Mangifera indica) ,waste products ,aqueous extracts ,glass transition ,functionality ,Chemical technology ,TP1-1185 - Abstract
This study investigated the potential uses of discarded mango peel and seed parts by analyzing their water sorption behavior, hydration kinetics, and stability when converted into extract powders at pH 3 and 10. The results revealed that peel extracts had a higher water adsorption capacity compared with seed extracts due to differences in their composition. Peel extracts were primarily composed of carbohydrates (approximately 75%) with a low protein content, while seed extracts contained fewer carbohydrates (less than 30%) but higher levels of proteins (more than 30%) and lipids. The critical water content for maintaining the glassy state of peel extract powders during storage was found to be 0.025 and 0.032 g of water/g for extracts obtained at pH 3 and 10, respectively. In contrast, the Tg values of seed extracts remained relatively unchanged across different water content levels, suggesting that proteins and lipids inhibited the water’s plasticizing effect in the solid matrix. These findings indicate that both mango waste fractions exhibit distinct hygroscopic behaviors, necessitating different approaches to processing and utilization. These extracts hold potential applications for various food products such as beverages, gels, sauces, or emulsions, contributing to the reduction in waste and the creation of value-added products from mango residues.
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- 2023
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16. Cannabinoid receptor type 2 agonist JWH-133 decreases cathepsin B secretion and neurotoxicity from HIV-infected macrophages
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Lester J. Rosario-Rodríguez, Yamil Gerena, Luis A. García-Requena, Luz J. Cartagena-Isern, Juan C. Cuadrado-Ruiz, Gabriel Borges-Vélez, and Loyda M. Meléndez
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Medicine ,Science - Abstract
Abstract HIV-associated neurocognitive disorders (HAND) are prevalent despite combined antiretroviral therapy (cART), affecting 52% of people living with HIV. Our laboratory has demonstrated increased expression of cathepsin B (CATB) in postmortem brain tissue with HAND. Increased secretion of CATB from in vitro HIV-infected monocyte-derived macrophages (MDM) induces neurotoxicity. Activation of cannabinoid receptor type 2 (CB2R) inhibits HIV-1 replication in macrophages and the neurotoxicity induced by viral proteins. However, it is unknown if CB2R agonists affect CATB secretion and neurotoxicity in HIV-infected MDM. We hypothesized that HIV-infected MDM exposed to CB2R agonists decrease CATB secretion and neurotoxicity. Primary MDM were inoculated with HIV-1ADA and treated with selective CB2R agonists JWH-133 and HU-308. HIV-1 p24 and CATB levels were determined from supernatants using ELISA. MDM were pre-treated with a selective CB2R antagonist SR144528 before JWH-133 treatment to determine if CB2R activation is responsible for the effects. Neuronal apoptosis was assessed using a TUNEL assay. Results show that both agonists reduce HIV-1 replication and CATB secretion from MDM in a time and dose-dependent manner and that CB2R activation is responsible for these effects. Finally, JWH-133 decreased HIV/MDM-CATB induced neuronal apoptosis. Our results suggest that agonists of CB2R represent a potential therapeutic strategy against HIV/MDM-induced neurotoxicity.
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- 2022
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17. Two New Species of Pristimantis (Anura: Strabomantidae) from Amazonas Department in Northeastern Peru
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Pablo J. Venegas, Luis A. García-Ayachi, and Alessandro Catenazzi
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advertisement call ,cloud forest ,Cordillera de Colán ,montane forest ,new species ,Peruvian Yungas ,Biology (General) ,QH301-705.5 - Abstract
We describe two new species of terrestrial-breeding frogs in the genus Pristimantis from the Andes of northeastern Peru, Amazonas Department. Both species share several characters with other congeners from northern Peru, such as the presence of prominent conical tubercles on their eyelids and heel, prominent conical tubercles along the outer edge of the tarsus, and discs on fingers and toes widely expanded. However, both species can be diagnosed from morphologically similar Pristimantis in the region. Pristimantis kiruhampatu has axillae, groins, and hidden surfaces of hindlimbs that are cherry with white minute flecks, tympanic membrane and tympanic annulus evident, conical tubercles along the edge of snout and outer edge of tibia, and \/ shaped folds in the scapular region. Pristimantis paulpittmani has yellow or dirty cream groins and hidden surfaces of hindlimbs, whitish cream irises with scattered dark brown reticulations, and a thin vertical dark brown streak at the middle of the eye, snout subacuminate with a conical tubercle at the tip, and lacks a tympanic annulus and membrane. Additionally, we provide a short description of the advertisement call of P. kiruhampatu.
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- 2021
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18. Natural products, including a new caboxamycin, from Streptomyces and other Actinobacteria isolated in Spain from storm clouds transported by Northern winds of Arctic origin
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Aida Sarmiento-Vizcaíno, Jesús Martín, Francisco Javier Ortiz-López, Fernando Reyes, Luis A. García, and Gloria Blanco
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caboxamycin B ,antibiotic ,antitumor ,streptomyces ,micromonospora ,nocardiopsis ,Chemistry ,QD1-999 - Abstract
Actinobacteria, mostly Streptomyces species, are the main source of natural products essential in medicine. While the majority of producer microorganisms of secondary metabolite are reported from terrestrial or marine environments, there are limited reports of their isolation from atmospheric precipitations. Clouds are considered as atmospheric oases for microorganisms and there is a recent paradigm shift whereby atmospheric-derived Actinobacteria emerge as an alternative source for drug discovery. In this context, we studied a total of 18 bioactive Actinobacteria strains, isolated by sampling nine precipitation events with prevailing Northern winds in the Cantabrian Sea coast, Northern Spain. Backward trajectories meteorological analyses indicate that air masses were originated mostly in the Arctic Ocean, and their trajectory to downwind areas involved the Atlantic Ocean and also terrestrial sources from continental Europe, and in some events from Canada, Greenland, Mauritania and Canary Islands. Taxonomic identification of the isolates, by 16S rRNA gene sequencing and phylogenetic analyses, revealed that they are members of three Actinobacteria genera. Fifteen of the isolates are Streptomyces species, thus increasing the number of bioactive species of this genus in the atmosphere to a 6.8% of the total currently validated species. In addition, two of the strains belong to the genus Micromonospora and one to genus Nocardiopsis. These findings reinforce a previous atmospheric dispersal model, extended herein to the genus Micromonospora. Production of bioactive secondary metabolites was screened in ethyl acetate extracts of the strains by LC-UV-MS and a total of 94 secondary metabolites were detected after LC/MS dereplication. Comparative analyses with natural products databases allowed the identification of 69 structurally diverse natural products with contrasted biological activities, mostly as antibiotics and antitumor agents, but also anti-inflammatory, antiviral, antiparasitic, immunosuppressant and neuroprotective among others. The molecular formulae of the 25 remaining compounds were determined by HRMS. None of these molecules had been previously reported in natural product databases indicating potentially novel metabolites. As a proof of concept, a new metabolite caboxamycin B (1) was isolated from the culture broth of Streptomyces sp. A-177 and its structure was determined by various spectrometric methods. To the best of our knowledge, this is the first novel natural product obtained from an atmospheric Streptomyces, thus pointing out precipitations as an innovative source for discovering new pharmaceutical natural products.
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- 2022
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19. Chemical, technological, and rheological properties of hydrocolloids from sesame (Sesamum indicum) with potential food applications
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Santander E. Lastra-Ripoll, Somaris E. Quintana, and Luis A. García-Zapateiro
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Sesame ,Hydrocolloids ,Rheology ,Carreau-Yasuda ,Functional properties ,Chemistry ,QD1-999 - Abstract
Background: Hydrocolloids are hydrophilic biopolymers which are widely used in the food industry due to their functional properties. In the present study, sesame hydrocolloids (Sesamum indicum) were obtained and, consequently, their physicochemical, proximal composition, functional, and rheological properties were evaluated to establish their potential applications in the food industry. Methods: Hydrocolloids were obtained from sesame seeds at 80 °C on evaluating the pH at 3, 7, and 10 and specific flour: water ratios during the solubilization process. Results: The hydrocolloids obtained had a good relationship between carbohydrates and proteins, which increased their potential use in the development of colloidal systems. The samples had high water holding capacity, solubility, and appropriate emulsifying and foaming properties. The hydrocolloids showed non-Newtonian shear-thinning behavior, adjusted to the Carreau-Yasuda model. Based on the dynamic viscoelastic rheological test, samples were characterized as a gel-like state when storage modulus values were higher than the loss modulus in the frequency and temperature ranges investigated. Conclusion: The findings revealed that sesame seeds can be considered appropriate raw material for extracting hydrocolloids as an alternative for obtaining natural food ingredients with interesting functional and rheological properties, with further applications in the development and formulation of micro-structured products.
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- 2022
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20. Significant rise in SARS-CoV-2 reinfection rate in vaccinated Hospital workers during the omicron wave: A prospective cohort study
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Eric Ochoa-Hein, Patricia E. Leal-Morán, Karen A. Nava-Guzmán, Abril T. Vargas-Fernández, José F. Vargas-Fernández, Fabricio Díaz-Rodríguez, Joel Armando Rayas-Bernal, Ricardo González-González, Pavel Vázquez-González, Martha A. Huertas-Jiménez, Sandra Rajme-López, Pilar Ramos-Cervantes, Violeta Ibarra-González, Luis A. García-Andrade, Fernando Ledesma-Barrientos, Alfredo Ponce-de-León, José Sifuentes-Osornio, and Arturo Galindo-Fraga
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COVID-19 ,SARS-CoV-2 ,Reinfection ,Health personnel ,Omicron. ,Internal medicine ,RC31-1245 - Abstract
Background: Relatively low SARS-CoV-2 reinfection rates have been reported in vaccinated individuals, but updates considering the Omicron variant are lacking. Objective: The objective of the study was to provide a current estimate of the SARS-CoV-2 reinfection rate in a highly immunized population. Methods: A prospective cohort of Mexican hospital workers was followed (March 2020-February 2022). Reinfection was defined as the occurrence of two or more episodes of COVID-19 separated by a period of ≥ 90 days without symptoms. The reinfection rate was calculated as the number of reinfection episodes per 100,000 persons per day. Results: A total of 3732 medical consultations were provided to 2700 workers, of whom 1388 (51.4%) were confirmed COVID-19 cases. A total of 73 reinfection cases were identified, of whom 71 (97.3%) had completed their primary vaccination series and 22 (30.1%) had had a booster dose before the second episode. The overall reinfection rate was 23.1 per 100,000 persons per day (as compared to a rate of 1.9 per 100,000 persons per day before the Omicron wave). Conclusions: The SARS-CoV-2 reinfection rate rose significantly during the Omicron wave despite a high primary vaccination coverage rate. Almost one-third of reinfected workers had a vaccine booster ≥ 14 days before the last COVID-19 episode.
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- 2022
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21. A new species of wood lizard (Hoplocercinae, Enyalioides) from the Río Huallaga Basin in Central Peru
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Pablo J. Venegas, Germán Chávez, Luis A. García-Ayachi, Vilma Duran, and Omar Torres-Carvajal
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Evolution ,QH359-425 ,Life ,QH501-531 - Abstract
We report the discovery of a new species of Enyalioides from the premontane forest of the Río Huallaga basin in central Peru. The most similar and phylogenetically related species are E. binzayedi and E. rudolfarndti. However, the new species differs from E. binzayedi (state of character in parentheses) by having dorsal scales strongly keeled on paravertebral region and feebly keeled or smooth elsewhere (prominent medial keel on each dorsal scale), more dorsals in transverse row between dorsolateral crests at midbody 26–39, x̄ = 30.44 (22–31, x̄ = 27.57), and a conspicuous posteromedial black patch in the gular region of males (absent). Contrarily, adult males of the new species and E. rudolfarndti are readily distinguished by having a conspicuous posteromedial black patch in the gular region, absent in E. rudolfarndti, and by lacking a conspicuous orange blotch (faint if present) on the antehumeral region, as in E. rudolfarndti. We also present an updated molecular phylogenetic tree of hoplocercines, which strongly supports both referral of the newly discovered species to Enyalioides and its status as distinct from those recognized previously.
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- 2021
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22. A New Species of Toad (Anura: Bufonidae: Rhinella) from Northern Peru
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Edgar Lehr, Juan C. Cusi, Lily O. Rodriguez, Pablo J. Venegas, Luis A. García-Ayachi, and Alessandro Catenazzi
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amphibia ,Rhinella festae species Group ,earless ,cloud forest ,Departamento Amazonas ,Departamento San Martín ,Biology (General) ,QH301-705.5 - Abstract
We describe a new species of Rhinella from montane forests between 1788 and 2305 m a.s.l. in the Departamentos Amazonas and San Martín, Peru. We tentatively assign the new species to the Rhinella festae species Group based on morphological similarities with its other 19 members. It is characterised by large size (maximum SVL 91.6 mm in females), a pointed and protruding snout that is posteroventrally inclined, absence of a visible tympanic annulus and tympanic membrane, long parotoid glands in contact with upper eyelid, presence of a dorsolateral row of enlarged tubercles, outer dorsolateral tarsus surface with a subconical ridge of fused tubercles, and absence of subgular vocal sac and vocal slits in males. One specimen from Departamento Amazonas tested positive for Batrachochytrium dendrobatidis.
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- 2021
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23. An elusive new species of gymnophthalmid lizard (Cercosaurinae, Selvasaura) from the Andes of northern Peru
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Lourdes Y. Echevarría, Pablo J. Venegas, Luis A. García-Ayachi, and Pedro M. Sales Nunes
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Evolution ,QH359-425 ,Life ,QH501-531 - Abstract
We describe a new species of Selvasaura from the montane forests of the eastern slopes of the Andes in northern Peru, based on external and hemipenial morphological characters and previous phylogenetic analyses. The new species can be differentiated from the other two Selvasaura species in having keeled dorsal scales usually flanked by longitudinal striations, in adults and juveniles; adult males with a yellow vertebral stripe bordered by broad dark brown stripes on each side and a unilobed hemipenis surrounded by the branches of the sulcus spermaticus. The description of the new species contributes information about new states of diagnostic characters of Selvasaura and natural history.
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- 2021
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24. Beauty is in the eye of the beholder: Cruciform eye reveals new species of direct-developing frog (Strabomantidae, Pristimantis) in the Amazonian Andes
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Germán Chávez, Luis A. García-Ayachi, and Alessandro Catenazzi
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Evolution ,QH359-425 ,Life ,QH501-531 - Abstract
We describe a new species of frog from the eastern slopes of the Andes in central Peru. Pristimantis sira sp. nov. has a distinctive crossing mark on the iris and no tympanum. The new species is closely related to P. antisuyu Catenazzi & Lehr, 2018, P. cruciocularis Lehr, Lundberg, Aguilar & von May, 2006, and P. erythroinguinis Catenazzi & Lehr, 2018, but is easily differentiable by lacking colour blotches on groins. Pristimantis sira sp. nov. inhabits the mountain forests from 1550 to 2200 m a.s.l., inside a national reserve threatened by illegal mining.
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- 2021
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25. A new species of marsupial frog (Anura; Gastrotheca) from the Cordillera de Colán in northeastern Peru
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Pablo J. Venegas, Luis A. García-Ayachi, Lourdes Y. Echevarría, Daniel J. Paluh, Juan C. Chávez–Arribasplata, Axel Marchelie, and Alessandro Catenazzi
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Zoology ,QL1-991 - Abstract
We describe a new species of marsupial frog, genus Gastrotheca, using morphological characters and molecular data as lines of evidence. The new species was discovered in the páramo and the ecotone between páramo and humid montane forest of Cordillera de Colán, at elevations between 3136 and 3179 m a.s.l., in northeastern Peru. The new species is distinguished from all its congeners by the combination of the following characters: coarsely granular skin on dorsum, a green dorsal coloration without pattern, finger I shorter than finger II, turquoise iris, and a venter without blotches, flecks or dots. Furthermore, we include a detailed osteological description of the new Gastrotheca species based on Micro-CT scanning. Based on our phylogenetic analyses, the new species belongs to the Gastrotheca marsupiata species group, is sister to G. oresbios and closely related to G. psychrophila, G. spectabilis, G. stictopleura and one undescribed species. Additionally, we test for the presence of the fungal pathogen Batrachochytrium dendrobatidis (Bd). No Bd infection was detected for G. gemma sp. nov. specimens but Bd prevalence was detected among syntopic frogs.
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- 2021
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26. Fully metallic geodesic lenses as analog electromagnetic models of static and spherically symmetric gravitational fields
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Falcón-Gómez, Enderson, De Falco, Vittorio, Abdalmalak, Kerlos Atia, Amor-Martín, Adrián, De La Rubia, Valentín, Santamaría-Botello, Gabriel, and Muñoz, Luis Enrique García
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General Relativity and Quantum Cosmology ,High Energy Physics - Theory - Abstract
We demonstrate that a fully metallic and air-filled geodesic waveguide can be employed as an analog electromagnetic model of a static and spherically symmetric gravitational field. By following the Plebanski formalism, a space-time metric of the aforementioned type is firstly encoded into the electromagnetic properties of a flat space-time region in the form of an isotropic and radially varying refractive index distribution. Then, a three-dimensional, air-filled, and axially symmetric waveguide, composed of two equally spaced and curved metallic surfaces, is employed. Its shape is tailored such that the effective paths, followed by transverse electromagnetic beams of microwave radiation within this waveguide, result equivalent to null-geodesics taking place in the aforementioned refractive medium. This strategy avoids the need for a refractive medium, although it only allows to reproduce the space-time metric on the invariant plane. Two analog electromagnetic models of gravity, using the proposed approach, are designed to reproduce the metric of both a Schwarzschild black hole and a Morris-Thorne wormhole. The results from full-wave simulations demonstrate that a one-dimensional Gaussian beam faithfully follows a path completely equivalent to general relativistic null geodesics with a mean relative error within 4%., Comment: 16 pages, 6 figures, accepted for publication in Physical Review D
- Published
- 2024
27. Positive Steady-State Varieties of Small Chemical Reaction Networks
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Curiel, Maize, Farr, Elise, Fries, Galileo, Puente, Luis David García, Hutchins, Julian, and Hoang, Vuong Nguyen
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Mathematics - Algebraic Geometry ,65H10, 92E20, 12D10 - Abstract
Chemical reaction network theory is a field of applied mathematics concerned with modeling chemical systems, and can be used in other contexts such as in systems biology to study cellular signaling pathways or epidemiology to study the effect of human interaction on the spread of disease. In this paper, we seek to understand a chemical reaction network's equilibrium points through the lens of algebraic geometry by computing the positive part of the steady-state variety defined by polynomial equations arising from the assumption of mass-action kinetics. We provide a systematic classification of positive steady-state varieties produced by 2-species, 2-reaction networks, grounded in combinatorial and algebraic properties. While some (restricted) techniques exist to fully understand the ideal defining the positive steady-state variety, this computation presents a significant challenge in general. Our classification theorems provide a simplification of previous criteria, and aim to provide a foundation for future analysis of larger networks.
- Published
- 2024
28. Four new species of Stenocercus Duméril & Bibron, 1837 (Squamata, Iguania) from the Department of Amazonas in northeastern Peru
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Pablo J. Venegas, Luis A. García-Ayachi, Juan C. Chávez-Arribasplata, Germán Chávez, Iván Wong, and Antonio García-Bravo
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Evolution ,QH359-425 ,Life ,QH501-531 - Abstract
The tropical Andes are known to be the richest and most diverse place on earth. This mountainous region covers almost one third of the Peruvian territory, and its herpetofauna remains poorly known. The lizard genus Stenocercus Duméril & Bibron, 1837 contains 69 species and most of them occur in the tropical Andes, although some exist as high as 4000 m a.s.l. The examination of newly collected material from the Andes of northern Peru in the Department of Amazonas reveals four new species of Stenocercus which we describe below. Of these four new species, three inhabit the ecoregion of Peruvian Yungas at elevations of 1460 to 2370 m a.s.l., and one the Marañón dry forest ecoregion at elevations of 1340 to 1470 m a.s.l. Additionally, we provide new data about coloration, natural history and distribution of the poorly known S. aculeatus O’Shaughnessy, 1879; and discuss the identity of some populations of S. prionotus Cadle, 2001 and S. scapularis Boulenger, 1901.
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- 2020
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29. Feasibility study to identify women of childbearing age at risk of pregnancy not using any contraception in The Health Improvement Network (THIN) database
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Lucía Cea Soriano, Alex Asiimwe, Mieke Van Hemelrijck, Cecilia Bosco, and Luis A. García Rodríguez
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Database ,Pregnancy ,Feasibility ,Contraception ,THIN ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
Abstract Background Worldwide the rate of unplanned pregnancies is more than 40%. Identifying women at risk of pregnancy can help prevent negative outcomes and also reduce healthcare costs of potential complications. It can also allow the investigation of the natural history of pregnancy outcomes, such as ectopic pregnancies or miscarriages. The use of medical records databases has been a crucial development in the field of pharmacoepidemiology – e.g. The Health Improvement Network (THIN) database is a validated database representative of the UK population. This project aimed to test the feasibility of identifying a population of women of childbearing age who are at risk of pregnancy not using any contraception in THIN database. Methods First a cohort of women of childbearing age (15-45yo) was identified. By applying a computer-based algorithm, containing codes for contraception methods or other suggestion of contraception, the risk of pregnancy was then ascertained. Next, two validation steps were implemented: 1) Revision of medical records/free text and 2) Questionnaires were sent to primary care practitioners (PCP) of women whose medical records had been reviewed. Positive predicted values (PPV) were calculated. Results A total of 266,433 women were identified in THIN. For the first validation step, 123 records were reviewed, with a PPV of 99.2% (95%CI: 95.5–99.9). For the questionnaires step, the PPV was of 82.3% (95%CI: 70–91.1). Information on sexual behaviour and attitudes towards conception was not captured by THIN. Conclusion This study shows that by applying a comprehensive computer-based algorithm, THIN can be used to identify women at risk of pregnancy.
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- 2020
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30. Comparación de la castración quirúrgica al nacimiento versus inmunocastration sobre las características de la canal y carne en machos Holstein
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Jorge A. Cervantes-Cazares, Cristina Pérez-Linares, Fernando Figueroa-Saavedra, Alma R. Tamayo-Sosa, Alberto Barreras-Serrano, Francisco G. Ríos-Rincón, Eduardo Sánchez-López, Isaa C. García-Reynoso, Pedro Mendoza Peraza, Angelina León Villanueva, and Luis A. García-Vega
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inmunocastración ,machos holstein ,evaluación de la canal ,Animal culture ,SF1-1100 ,Veterinary medicine ,SF600-1100 - Abstract
El objetivo fue comparar el efecto de la castración quirúrgica al nacimiento vs inmunocastración, sobre las características de la canal y carne en machos Holstein en engorda; se utilizaron 720 machos Holstein aproximadamente de 7 a 8 meses de edad con peso inicial de 240.82 kg. Se formaron 2 tratamientos con 4 corrales de 90 animales en cada uno: toros castrados quirúrgicamente que fueron castrados 24 h después del nacimiento y toros inmunocastrados vacunados con Bopriva aplicando cuatro dosis, al día 1, 21, 101 y 181 de engorda. Se tomaron pesos individuales en cada vacunación. Los animales se sacrificaron a los 242 días de engorda. A partir de la segunda vacunación se observaron diferencias (P0.05) entre tratamientos mientras que los valores de b*, C* y H* fueron más altos (P
- Published
- 2020
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31. Author's reply to SARS-CoV-2 reinfection rate in vaccinated hospital workers: correspondence
- Author
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Eric Ochoa-Hein, Patricia E. Leal-Morán, Karen A. Nava-Guzmán, Abril T. Vargas-Fernández, José F. Vargas-Fernández, Fabricio Díaz-Rodríguez, Joel Armando Rayas-Bernal, Ricardo González-González, Pavel Vázquez-González, Martha A. Huertas-Jiménez, Sandra Rajme-López, Pilar Ramos-Cervantes, Violeta Ibarra-González, Luis A. García-Andrade, Fernando Ledesma-Barrientos, Alfredo Ponce-de-León, José Sifuentes-Osornio, and Arturo Galindo-Fraga
- Subjects
Internal medicine ,RC31-1245 - Published
- 2022
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32. Ultrasound-Assisted Extraction of Mango (Mangifera indica) Kernel Starch: Chemical, Techno-Functional, and Pasting Properties
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Luis Mieles-Gómez, Somaris E. Quintana, and Luis A. García-Zapateiro
- Subjects
mango kernel starch ,ultrasound ,techno-functional properties ,chemical properties ,pasting properties ,Science ,Chemistry ,QD1-999 ,Inorganic chemistry ,QD146-197 ,General. Including alchemy ,QD1-65 - Abstract
(1) Background: Starch is the main component of mango (Mangifera indica) kernel, making it an alternative to obtain an ingredient from a non-conventional source with potential application in food and other industrial applications; however, reports on the use of new extraction techniques for this material are scarce. The main objective of this research was to evaluate the effect of ultrasound-assisted extraction (UAE) on the yield, chemical, techno-functional, rheological, and pasting properties of starch isolated from a non-conventional source such as a mango kernel. (2) Methods: Different power sonication conditions (120, 300, and 480 W) and sonication time (10, 20, and 30 min) were evaluated along with a control treatment (extracted by the wet milling method). (3) Results: Ultrasound-assisted extraction increases starch yield, with the highest values (54%) at 480 W and 20 min. A significant increase in the amylose content, water-holding capacity, oil-holding capacity, solubility, and swelling power of ultrasonically extracted starches was observed. Similarly, mango kernel starch (MKS) exhibited interesting antioxidant properties. The sol-gel transition temperature and pasting parameters, such as the breakdown viscosity (BD) and the setback viscosity (SB), decreased with ultrasound application; (4) Conclusion: indicating that ultrasound caused changes in physical, chemical, techno-functional, rheological, and pasting properties, depending on the power and time of sonication, so it can be used as an alternative starch extraction and modification technique, for example, for potential application in thermally processed food products such as baked goods, canned foods, and frozen foods.
- Published
- 2023
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33. Embedded-AMP: A Multi-Thread Computational Method for the Systematic Identification of Antimicrobial Peptides Embedded in Proteome Sequences
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Germán Meléndrez Carballo, Karen Guerrero Vázquez, Luis A. García-González, Gabriel Del Rio, and Carlos A. Brizuela
- Subjects
antimicrobial peptides ,embedded peptides ,machine learning ,autophagy ,longevity ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Antimicrobial peptides (AMPs) have gained the attention of the research community for being an alternative to conventional antimicrobials to fight antibiotic resistance and for displaying other pharmacologically relevant activities, such as cell penetration, autophagy induction, immunomodulation, among others. The identification of AMPs had been accomplished by combining computational and experimental approaches and have been mostly restricted to self-contained peptides despite accumulated evidence indicating AMPs may be found embedded within proteins, the functions of which are not necessarily associated with antimicrobials. To address this limitation, we propose a machine-learning (ML)-based pipeline to identify AMPs that are embedded in proteomes. Our method performs an in-silico digestion of every protein in the proteome to generate unique k-mers of different lengths, computes a set of molecular descriptors for each k-mer, and performs an antimicrobial activity prediction. To show the efficiency of the method we used the shrimp proteome, and the pipeline analyzed all k-mers between 10 and 60 amino acids in length to predict all AMPs in less than 20 min. As an application example we predicted AMPs in different rodents (common cuy, common rat, and naked mole rat) with different reported longevities and found a relation between species longevity and the number of predicted AMPs. The analysis shows as the longevity of the species is higher, the number of predicted AMPs is also higher. The pipeline is available as a web service.
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- 2023
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34. Mechanosynthesis of Mesoporous Bi-Doped TiO2: The Effect of Bismuth Doping and Ball Milling on the Crystal Structure, Optical Properties, and Photocatalytic Activity
- Author
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Sofía Estrada-Flores, Catalina M. Pérez-Berumen, Tirso E. Flores-Guia, Luis A. García-Cerda, Joelis Rodríguez-Hernández, Tzipatly A. Esquivel-Castro, and Antonia Martínez-Luévanos
- Subjects
bismuth-doped TiO2 ,crystal structure ,mechanosynthesis ,optical properties ,photocatalytic activity ,Crystallography ,QD901-999 - Abstract
In this work, we reported obtaining mesoporous Bi-doped TiO2 by mechanosynthesis and bismuth loading of 0%, 1%, 3%, 5%, and 10% (milled TiO2, TiO2 Bi 1%, TiO2 Bi 3% TiO2 Bi 5%, and TiO2 Bi 10%, respectively). The effect of bismuth doping and ball milling on the crystal structure, optical properties, and photocatalytic performance of Bi-doped TiO2 mesoporous samples under UV, visible, and sun irradiation was investigated. According to the results of the Rietveld refinement, the estimated chemical formulas for the TiO2 Bi 1%, TiO2 Bi 3%, TiO2 Bi 5%, and TiO2 Bi10% samples were Ti0.99Bi0.01O2, Ti0.97Bi0.03O2, Ti0.96Bi0.04O2, and Ti0.91Bi0.09O2 respectively. The incorporation of Bi into the TiO2 lattice causes the crystallite size to decrease and, consequently, the absorption spectrum of TiO2 to extend into the visible region of the electromagnetic spectrum, resulting in a lower band gap (Eg) value. Bi-doped TiO2 mesoporous samples had Eg values of 2.90 eV, 2.83 eV, 2.77 eV, and 2.70 eV for the TiO2 Bi 1%, TiO2 Bi 3%, TiO2 Bi 5%, and TiO2 Bi 10% samples, respectively. Photocatalytic removal of methylene blue (MB) data fit well for second-order kinetics. Photocatalytic activity increase followed the order of TiO2 Bi 5% > TiO2 Bi 10% > TiO2 Bi 3% > TiO2 Bi 1% > pristine TiO2. The TiO2 Bi 5% sample exhibited excellent photocatalytic performance for MB photodegradation under natural sunlight (89.2%).
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- 2022
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35. Bioactive Natural Products in Actinobacteria Isolated in Rainwater From Storm Clouds Transported by Western Winds in Spain
- Author
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Aida Sarmiento-Vizcaíno, Jesús Martín, Fernando Reyes, Luis A. García, and Gloria Blanco
- Subjects
Streptomyces ,Nocardiopsis ,actinomycetes ,antibiotic ,antimicrobial ,antitumor ,Microbiology ,QR1-502 - Abstract
Actinobacteria are the main producers of bioactive natural products essential for human health. Although their diversity in the atmosphere remains largely unexplored, using a multidisciplinary approach, we studied here 27 antibiotic producing Actinobacteria strains, isolated from 13 different precipitation events at three locations in Northern and Southern Spain. Rain samples were collected throughout 2013–2016, from events with prevailing Western winds. NOAA HYSPLIT meteorological analyses were used to estimate the sources and trajectories of the air-mass that caused the rainfall events. Five-day backward air masses trajectories of the diverse events reveals a main oceanic source from the North Atlantic Ocean, and in some events long range transport from the Pacific and the Arctic Oceans; terrestrial sources from continental North America and Western Europe were also estimated. Different strains were isolated depending on the precipitation event and the latitude of the sampling site. Taxonomic identification by 16S rRNA sequencing and phylogenetic analysis revealed these strains to belong to two Actinobacteria genera. Most of the isolates belong to the genus Streptomyces, thus increasing the number of species of this genus isolated from the atmosphere. Furthermore, five strains belonging to the rare Actinobacterial genus Nocardiopsis were isolated in some events. These results reinforce our previous Streptomyces atmospheric dispersion model, which we extend herein to the genus Nocardiopsis. Production of bioactive secondary metabolites was analyzed by LC-UV-MS. Comparative analyses of Streptomyces and Nocardiopsis metabolites with natural product databases led to the identification of multiple, chemically diverse, compounds. Among bioactive natural products identified 55% are antibiotics, both antibacterial and antifungal, and 23% have antitumor or cytotoxic properties; also compounds with antiparasitic, anti-inflammatory, immunosuppressive, antiviral, insecticidal, neuroprotective, anti-arthritic activities were found. Our findings suggest that over time, through samples collected from different precipitation events, and space, in different sampling places, we can have access to a great diversity of Actinobacteria producing an extraordinary reservoir of bioactive natural products, from remote and very distant origins, thus highlighting the atmosphere as a contrasted source for the discovery of novel compounds of relevance in medicine and biotechnology.
- Published
- 2021
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36. Development of new eggplant spread product: A rheological and chemical characterization
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Luis Mieles-Gómez, Somaris E. Quintana, and Luis A. García-Zapateiro
- Subjects
Eggplant (Solanum melongena) ,Food paste ,Sensory evaluation ,Rheology ,Spreadability ,Viscoelasticity ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Eggplant (Solanum melongena) is an important vegetable of the Nightshade family with high demand due to its nutritional value and medicinal properties. The principal objective of this work was to develop and standardize a spread eggplant paste (SEP) with the addition of guar gum and evaluate its physicochemical, bromatological, sensory, and rheological characteristics. A two-factor factorial design with three levels was used for the formulation, evaluating the percentage of guar gum and oil. Flow curves in steady-state and small-amplitude oscillatory shear tests were performed to evaluate the rheological properties of the pastes. Sensorial analysis was performed using descriptive analysis. The standardized eggplant showed no signs of phase separation being stable during storage. Samples presented a non-Newtonian shear-thinning behavior described by Ostwald de-Waele model (R2 > 0.969). The products exhibit more elastic than viscous behavior, with a higher storage modulus than loss modulus in the evaluated frequency range, where the modules could be well described by a power function of the oscillatory frequency. The sensory evaluation revealed that the product color, odor, taste, and spreadability were acceptable, being an alternative for the transformation and agro-industrial use of eggplant for production chain development.
- Published
- 2021
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37. PCR utility over conventional tests for detection of Mycobacterium spp. in patients with mastitis and granulomatous lymphadenitis: Case series
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José J. Márquez-Barajas, Manuel Solano-Genesta, Leonora Valdez-Rojas, Johana J. Garnica-Vázquez, José F. Anaya-Gómez, Sergio A. Trujillo-Vega, Oscar Bañuelos-Robles, Guillermo E. Juárez-López, Estefania N. Valdés-Peregrina, Cristina A. Luna-González, and Luis A. García-González
- Subjects
Quantitative polymerase chain reaction. Mycobacterium spp. Granulomatous mastitis. Granulomatous lymphadenitis. ,Medicine (General) ,R5-920 - Abstract
Objective: The present study aims to highlight the utility of quantitative polymerase chain reaction (qPCR) as a method for identifying typical and atypical mycobacterial infections in patients with mastitis and granulomatous lymphadenitis. Materials and methods: A total of five patients initially diagnosed with mastitis or granulomatous lymphadenitis based on their clinical characteristics in whom conventional tests were used as a diagnostic method were selected. Conclusion: The present study showed that the routine performance of qPCR for typical and atypical mycobacteria allows for improved diagnosis.
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- 2021
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38. Reseñas
- Author
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Miguel Ángel Ladero Quesada, Luis A. García Moreno, José Antonio Pizarro Pizarro, Stéphane Boissellier, José Ángel García de Cortázar, Flocel Sabaté, María Martínez, María Asenjo González, Pablo Ortego Rico, José Javier Ruiz Ibáñez, Marco Antonio Coronel Ramos, Hilario Casado Alonso, David González Cruz, Rafael M. Girón Pascual, Ana Crespo Solana, Antoni Picazo Muntaner, David Alonso García, Francisco Andújar Castillo, Manuel Bustos Rodríguez, Carsten Humlebæk, Ignacio Olábarri Gortázar, Sergio Valero Gómez, Ángeles González-Fernández, Steven Forti, Fernando del Rey, Guillermo Á. Pérez Sánchez, Francisco Cobo Romero, Antonio Míguez Macho, Pere Ysàs, Mª Carmen Cánovas Ortega, and José Antonio Parejo Fernández
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Social Sciences - Published
- 2019
39. Low-dose aspirin and risk of upper/lower gastrointestinal bleeding by bleed severity: a cohort study with nested case-control analysis using primary care electronic health records from the United Kingdom
- Author
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Luis A. García Rodríguez, Angel Lanas, Montse Soriano-Gabarró, and Lucía Cea Soriano
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Upper gastrointestinal bleeding ,lower gastrointestinal bleeding ,aspirin ,Medicine - Abstract
Introduction Risks of low-dose aspirin-associated upper and lower gastrointestinal bleeds (UGIB/LGIB) may vary by severity and presence of cardiovascular disease (CVD). No study has quantified these risks for UGIB and LGIB in the same real-world study population.Patients and methods Using UK primary care data, 199,049 new users of low-dose aspirin (75–300 mg/day) and 1:1 matched non-users were followed to identify incident UGIB (N = 1843)/LGIB (N = 2763) cases. Nested case-control analyses compared current low-dose aspirin vs. non-use on UGIB/LGIB risk.Results Adjusted incidence rate ratios (ORs; 95% CIs) were 1.62 (1.42–1.86) for non-fatal UGIB, 1.63 (1.47–1.81) for non-fatal LGIB, 0.77 (0.51–1.16) for fatal UGIB, 1.29 (0.50–3.36) for fatal LGIB. For hospitalizations, adjusted ORs (95% CIs) were 1.55 (1.32–1.81) for UGIB and 1.89 (1.58–2.27) for LGIB; for referred only cases, they were 1.52 (1.26–1.84) for UGIB and 1.54 (1.37–1.73) for LGIB. In primary CVD prevention, adjusted ORs (95% CI) were 1.62 (1.38–1.90) for UGIB and 1.60 (1.42–1.81) for LGIB; in secondary CVD prevention, they were 1.16 (0.89–1.50) for UGIB and 1.67 (1.34–2.09) for LGIB.Conclusion Low-dose aspirin was associated with increased risks of non-fatal but not fatal UGIB/LGIB.Key messageLow-dose aspirin is associated with an increased risks of non-fatal UGIB/LGIB but not fatal UGIB/LGIB.
- Published
- 2019
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40. Feasibility and validity of The Health Improvement Network database of primary care electronic health records to identify and characterise patients with small cell lung cancer in the United Kingdom
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Lucía Cea Soriano, Jihong Zong, and Luis A. García Rodríguez
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Small cell lung carcinoma ,Database ,Incidence ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Epidemiological research on small cell lung cancer (SCLC) is limited and based on cancer registry data. We evaluated the feasibility and validity of using primary care electronic health records (The Health Improvement Network [THIN]) in the UK to identify and characterise SCLC. Methods We searched THIN records of individuals aged 18–89 years between 2000 and 2014 for a first diagnostic code suggestive of lung cancer (group 1) or small cell cancer (SCC; group 2) and for text strings among free text comments to identify and characterise incident SCLC cases. We validated our case identification strategy by manual review of patient EHRs, including free text comments, for a random sample of 400 individuals initially detected with a diagnostic code (300 from group 1 and 100 from group 2). Results Twenty five thousand two hundred fourty one individuals had a code for lung cancer (n = 24,508 [97.1%]) or SCC (733 [2.9%]). Following free-text searches, there were 3530 incident SCLC cases (2956 from group 1; 574 from group 2) corresponding to an incidence rate of 1.01 per 10,000 person-years. In the validation exercise, SCLC confirmation rates were 99% (group 1) and 85% (group 2). Mean age at diagnosis among confirmed cases was 68.5 years; staging information was present in 63.5% of cases of whom 17.8% had limited disease and 82.2% had extensive disease. The majority (84.5%) had a recorded symptom suggestive of lung cancer; chest infection was the most common (18%) followed by cough (15.8%) and chest/abdominal/back pain (15.2%). The first year crude mortality rates was 9.9 per 100 person-months (95% confidence interval [CI] 9.5–10.4), was higher among men and those aged 80 years and above. A total of 144 (37.8%) confirmed cases had metastases recorded. Median survival among the whole study cohort was 7.37 months. Conclusions Our SCLC case identification method appears to be valid and could potentially be adapted to identify other cancer types. However, complete characterisation of staging requires information from additional data sources including cancer registries.
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- 2019
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41. Novel Hydrocolloids Obtained from Mango (Mangifera indica) var. Hilaza: Chemical, Physicochemical, Techno-Functional, and Structural Characteristics
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Ronald Marsiglia-Fuentes, Somaris E. Quintana, and Luis A. García Zapateiro
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mango (Mangifera indica) var. hilaza ,waste products ,agroindustry ,hydrocolloids ,structure ,functionality ,Science ,Chemistry ,QD1-999 ,Inorganic chemistry ,QD146-197 ,General. Including alchemy ,QD1-65 - Abstract
Background: Hydrocolloids are ingredients used to improve the technological properties of products; currently, there is a growing demand from the food industry and consumers to use natural ingredients and reduce the environmental impact. Methods: This work evaluated the effect of pH on hydrocolloid extraction from the pulp, seed, and peel of mango (Mangifera indica) var. hilaza and their chemical, physicochemical, techno-functional, and structural properties. Results: The main component of the hydrocolloid was the carbohydrates for pulp (22.59%) and peel (24.05%), and the protein for seed (21.48%) was corroborated by NIR spectra and associated with the technological and functional properties. The solubility increases with the temperature presenting values higher than 75% at 80 °C; the swelling index was higher than 30%, while the water holding capacity was higher in samples with higher carbohydrate content (110–121%). Moreover, a higher content of total phenolic compounds (21.61 ± 0.39–51.77 ± 2.48 mg GAE/g) and antioxidant activity (≥193.82 μMol Trolox/g) was obtained. The pH of extraction changes the color parameters and microstructural properties. Conclusions: Novel ingredients from mango pulp, seed, and peel at different pH levels have technological and functional properties that are potential use in the food industry as an alternative to the development of microstructural products.
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- 2022
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42. Diseño de un dispositivo de asistencia ventilatoria temporal de lazo cerrado basado en bolsa válvula-mascarilla
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Jorge A. Balsells, Luis G. García, Iván Morales, Víctor López, Víctor Carranza, Saúl López, Astric C. Villatoro, Luis A. García, Juan C. Castillo, Hasel Nájera, and Héctor Cabrera
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Asistencia respiratoria automatizada ,bajo costo ,Animal culture ,SF1-1100 ,Medicine (General) ,R5-920 ,Science (General) ,Q1-390 - Abstract
Desde inicios del 2020, el mundo se ha visto afectado por la COVID-19 causada por el SARS-CoV-2, que en agosto lo padecen más de 31 millones de pacientes, algunos de los cuales presentan el síndrome de distrés respiratorio, que requiere de ventilación mecánica. Por el alto número de contagios, la disponibilidad de ventiladores para el tratamiento es escasa. Se presenta la descripción de un prototipo de un dispositivo de asistencia ventilatoria temporal de lazo cerrado de bajo costo; el AR_CODEX, basado en una bolsa válvula-mascarilla (BVM), que contribuye al mantenimiento ventilatorio mínimo del paciente durante un tiempo corto en casos donde no hay disponibilidad de ventiladores mecánicos. Para esto, se diseñó y construyó un sistema mecánico ajustable que compresiona la bolsa de ventilación, el cual cuenta con sensores de flujo y presión. Además, se elaboró una interfaz gráfica para un adecuado monitoreo del paciente y un sistema de control para variables como volumen, presión máxima, frecuencia respiratoria y relación inspiración:espiración. Por otro lado, existe un problema de sensibilidad en el sensor de flujo debido a varios factores, como la variación del voltaje en los motores. Adicionalmente, la implementación de un lazo cerrado es importante para compensar variaciones aleatorias en el funcionamiento del dispositivo. Es necesario realizar pruebas en animales para evaluar el correcto funcionamiento de AR_CODEX en seres vivos.
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- 2020
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43. Development of Dressing-Type Emulsion with Hydrocolloids from Butternut Squash Seed: Effect of Additives on Emulsion Stability
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Somaris E. Quintana, Edilbert Torregroza-Fuentes, and Luis A. García Zapateiro
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butternut squash seed ,hydrocolloids ,dressing-type emulsion ,rheological properties ,Science ,Chemistry ,QD1-999 ,Inorganic chemistry ,QD146-197 ,General. Including alchemy ,QD1-65 - Abstract
Background: Natural ingredients have been employed to develop food products. Methods: Hydrocolloids from butternut squash seeds (HBSSs) were extracted with water at pH 3, 7, and 10 and characterized bromatologically and rheologically; then these HBSSs were used to stabilize the dressing-type emulsion by evaluating its physicochemical, rheological, and microstructural properties. Results: Hydrocolloids presented higher protein (from 20.43 to 39.39%) and carbohydrate (from 50.05 to 52.68%) content and rheological properties with a predominant elastic modulus. HBSSs extracted at pH 10 were used for the development of the dressing-type emulsion. The samples were stable during the storage period (15 days), with a good microstructural organization showing non-Newtonian fluid properties with shear-thinning behavior when the pseudoplasticity and the oil droplet size decreased with the addition of HBSS. Conclusions: Hydrocolloid constituents were detected surrounding the droplets of the emulsions, intensifying the effects of inner droplet interaction due to depletion events and a strong influence on the structure and physical stability. The hydrocolloids used to stabilize the dressing-type emulsions are additively promising in microstructured food design.
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- 2022
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44. Trends in the contemporary incidence of colorectal cancer and patient characteristics in the United Kingdom: a population-based cohort study using The Health Improvement Network
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Lucía Cea Soriano, Montse Soriano-Gabarró, and Luis A. García Rodríguez
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Colorectal cancer ,Incidence ,United Kingdom ,Comorbidities ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Cancer registry data show that survival of colorectal cancer (CRC) in the United Kingdom is poor compared with other European countries and the United States, yet these data sources lack information on patient comorbidities and medication use, which could help explain these differences. Methods Among individuals aged 40–89 years in The Health Improvement Network (2000–2014), we identified first ever cases of CRC and calculated incidence rates with 95% confidence intervals (CIs). For CRC cases and non-cases in two separate calendar years (2002 and 2014), we evaluated patient demographics, lifestyle factors, comorbidities and medication use and bowel screening. Results The incidence of CRC remained relatively constant across the study period; incidence rates per 10,000 person-years (95% CIs) were 9.27 (8.59–1.01) in 2000, 10.65 (10.15–11.18) in 2007 and 8.37 (7.93–8.83) in 2014. Incidence rates per 10,000 person-years were higher in men than women at 11.44 (95% CI: 10.35-12.66) vs. 7.40 (95% CI: 6.59–8.32) in 2000, and 9.39 (95% CI: 8.74–10.10) vs. 7.38 (95% CI: 6.81–8.00) in 2014. An increase was seen in the proportion of CRC cases diagnosed at age
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- 2018
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45. Adaptive Artificial Immune Networks for Mitigating DoS flooding Attacks
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Vidal, Jorge Maestre, Orozco, Ana Lucila Sandoval, and Villalba, Luis Javier García
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Computer Science - Cryptography and Security - Abstract
Denial of service attacks pose a threat in constant growth. This is mainly due to their tendency to gain in sophistication, ease of implementation, obfuscation and the recent improvements in occultation of fingerprints. On the other hand, progress towards self-organizing networks, and the different techniques involved in their development, such as software-defined networking, network-function virtualization, artificial intelligence or cloud computing, facilitates the design of new defensive strategies, more complete, consistent and able to adapt the defensive deployment to the current status of the network. In order to contribute to their development, in this paper, the use of artificial immune systems to mitigate denial of service attacks is proposed. The approach is based on building networks of distributed sensors suited to the requirements of the monitored environment. These components are capable of identifying threats and reacting according to the behavior of the biological defense mechanisms in human beings. It is accomplished by emulating the different immune reactions, the establishment of quarantine areas and the construction of immune memory. For their assessment, experiments with public domain datasets (KDD'99, CAIDA'07 and CAIDA'08) and simulations on various network configurations based on traffic samples gathered by the University Complutense of Madrid and flooding attacks generated by the tool DDoSIM were performed.
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- 2024
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46. Compression effects and scene details on the source camera identification of digital videos
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López, Raquel Ramos, Orozco, Ana Lucila Sandoval, and Villalba, Luis Javier García
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Computer Science - Cryptography and Security - Abstract
The continuous growth of technologies like 4G or 5G has led to a massive use of mobile devices such as smartphones and tablets. This phenomenon, combined with the fact that people use mobile phones for a longer period of time, results in mobile phones becoming the main source of creation of visual information. However, its reliability as a true representation of reality cannot be taken for granted due to the constant increase in editing software. This makes it easier to alter original content without leaving a noticeable trace in the modification. Therefore, it is essential to introduce forensic analysis mechanisms to guarantee the authenticity or integrity of a certain digital video, particularly if it may be considered as evidence in legal proceedings. This paper explains the branch of multimedia forensic analysis that allows to determine the identification of the source of acquisition of a certain video by exploiting the unique traces left by the camera sensor of the mobile device in visual content. To do this, a technique that performs the identification of the source of acquisition of digital videos from mobile devices is presented. It involves 3 stages: (1) Extraction of the sensor fingerprint by applying the block-based technique. (2) Filtering the strong component of the PRNU signal to improve the quality of the sensor fingerprint. (3) Classification of digital videos in an open scenario, that is, where the forensic analyst does not need to have access to the device that recorded the video to find out the origin of the video. The main contribution of the proposed technique eliminates the details of the scene to improve the PRNU fingerprint. It should be noted that these techniques are applied to digital images and not to digital videos.
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- 2024
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47. Authentication and integrity of smartphone videos through multimedia container structure analysis
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Huamán, Carlos Quinto, Orozco, Ana Lucila Sandoval, and Villalba, Luis Javier García
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Computer Science - Cryptography and Security ,Computer Science - Machine Learning ,Computer Science - Multimedia ,Electrical Engineering and Systems Science - Image and Video Processing - Abstract
Nowadays, mobile devices have become the natural substitute for the digital camera, as they capture everyday situations easily and quickly, encouraging users to express themselves through images and videos. These videos can be shared across different platforms exposing them to any kind of intentional manipulation by criminals who are aware of the weaknesses of forensic techniques to accuse an innocent person or exonerate a guilty person in a judicial process. Commonly, manufacturers do not comply 100% with the specifications of the standards for the creation of videos. Also, videos shared on social networks, and instant messaging applications go through filtering and compression processes to reduce their size, facilitate their transfer, and optimize storage on their platforms. The omission of specifications and results of transformations carried out by the platforms embed a features pattern in the multimedia container of the videos. These patterns make it possible to distinguish the brand of the device that generated the video, social network, and instant messaging application that was used for the transfer. Research in recent years has focused on the analysis of AVI containers and tiny video datasets. This work presents a novel technique to detect possible attacks against MP4, MOV, and 3GP format videos that affect their integrity and authenticity. The method is based on the analysis of the structure of video containers generated by mobile devices and their behavior when shared through social networks, instant messaging applications, or manipulated by editing programs. The objectives of the proposal are to verify the integrity of videos, identify the source of acquisition and distinguish between original and manipulated videos.
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- 2024
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48. A novel pattern recognition system for detecting Android malware by analyzing suspicious boot sequences
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Vidal, Jorge Maestre, Monge, Marco Antonio Sotelo, and Villalba, Luis Javier García
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Computer Science - Cryptography and Security - Abstract
This paper introduces a malware detection system for smartphones based on studying the dynamic behavior of suspicious applications. The main goal is to prevent the installation of the malicious software on the victim systems. The approach focuses on identifying malware addressed against the Android platform. For that purpose, only the system calls performed during the boot process of the recently installed applications are studied. Thereby the amount of information to be considered is reduced, since only activities related with their initialization are taken into account. The proposal defines a pattern recognition system with three processing layers: monitoring, analysis and decision-making. First, in order to extract the sequences of system calls, the potentially compromised applications are executed on a safe and isolated environment. Then the analysis step generates the metrics required for decision-making. This level combines sequence alignment algorithms with bagging, which allow scoring the similarity between the extracted sequences considering their regions of greatest resemblance. At the decision-making stage, the Wilcoxon signed-rank test is implemented, which determines if the new software is labeled as legitimate or malicious. The proposal has been tested in different experiments that include an in-depth study of a particular use case, and the evaluation of its effectiveness when analyzing samples of well-known public datasets. Promising experimental results have been shown, hence demonstrating that the approach is a good complement to the strategies of the bibliography.
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- 2024
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49. A security framework for Ethereum smart contracts
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Vivar, Antonio López, Orozco, Ana Lucila Sandoval, and Villalba, Luis Javier García
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Computer Science - Cryptography and Security - Abstract
The use of blockchain and smart contracts have not stopped growing in recent years. Like all software that begins to expand its use, it is also beginning to be targeted by hackers who will try to exploit vulnerabilities in both the underlying technology and the smart contract code itself. While many tools already exist for analyzing vulnerabilities in smart contracts, the heterogeneity and variety of approaches and differences in providing the analysis data makes the learning curve for the smart contract developer steep. In this article the authors present ESAF (Ethereum Security Analysis Framework), a framework for analysis of smart contracts that aims to unify and facilitate the task of analyzing smart contract vulnerabilities which can be used as a persistent security monitoring tool for a set of target contracts as well as a classic vulnerability analysis tool among other uses.
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- 2024
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50. Digital Video Manipulation Detection Technique Based on Compression Algorithms
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Fernandez, Edgar Gonzalez, Orozco, Ana Lucila Sandoval, and Villalba, Luis Javier Garcia
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Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Cryptography and Security ,Computer Science - Machine Learning - Abstract
Digital images and videos play a very important role in everyday life. Nowadays, people have access the affordable mobile devices equipped with advanced integrated cameras and powerful image processing applications. Technological development facilitates not only the generation of multimedia content, but also the intentional modification of it, either with recreational or malicious purposes. This is where forensic techniques to detect manipulation of images and videos become essential. This paper proposes a forensic technique by analysing compression algorithms used by the H.264 coding. The presence of recompression uses information of macroblocks, a characteristic of the H.264-MPEG4 standard, and motion vectors. A Vector Support Machine is used to create the model that allows to accurately detect if a video has been recompressed.
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- 2024
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