2,635 research outputs found
ProducciĂłn de bovinos en la Argentina : de carne somos
Fil: Demarco, Diego. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: de la Orden, Jorge L. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Cervini, Lourdes M. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Gil, Susana. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaA pesar que desde 1990 el stock ganadero ha permanecido relativamente estancado,\nfundamentalmente por la competencia de la actividad agrĂcola, con mejores márgenes\neconĂłmicos, Argentina sigue siendo un importantĂsimo productor de carne vacuna, de\nexcelente calidad, el octavo exportador mundial y, por supuesto, el lĂder en el consumo\nper cápita
A combined experimental and theoretical study of the supramolecular self-assembly of the natural benzopyran 2,2-dimethyl-3-hydroxy-6-acetyl-chromane and its isomeric benzofuran 10,11-dihydro-10-hydroxytremetone
Epoxidation of 4HMBA, the main metabolite of the medicinal plant Sencecionutans, produces an unstable epoxide eventually giving rise to a mixture of four derivatives, three of them previously reported as natural products. The epoxide product easily undergoes an intra-molecular attack of the phenolic hydroxyl against the epoxide group carbons to produce either a benzofuran or a chromane derivative. When dissolved in methanol-water mixture at room temperature the epoxide is completely solvolyzed to give the corresponding diol (hydrolysis) or vicinal hydroxyl-methoxy (methanolysis) derivative. All the compounds involved in the above reactions were characterized by IR, Raman, H NMR and UV–vis spectroscopies, and by mass spectrometry. Density functional theory (DFT) computations were used to optimize the structure conformations. The optimized structures were further subjected to a Natural Bond Orbital (NBO) and electrostatic potentials analysis. The crystal structures of the title compounds (for short, 3 and 4 respectively) were determined by X-ray diffraction methods. Compound 3 crystallizes in the triclinic P-1 space group with a = 6.4289 (6) Ă…, b = 8.7120 (6) Ă…, c = 10.952 (1) Ă…, α = 92.280 (7)°, β = 95.738 (7)°, Îł = 103.973 (7)°, and Z = 2 molecules per unit cell and 4 in the monoclinic P21/c space group with a = 11.2891 (6) Ă…, b = 9.1902 (4) Ă…, c = 12.4272 (7) Ă…. Î’ = 113.689 (7)°, and Z = 4. In 3 neighboring molecules are linked to each other by OHâ‹ŻO (keto) bonds giving rise to a polymeric structure. In 4 the OH group is a bifurcate H-bond donor. It forms a weak intra-molecular OHâ‹ŻO (furan) bond and also a much stronger inter-molecular OHâ‹ŻO (keto) bond giving rise to a zig-zag polymeric structure. A detailed analysis of the solid state molecular interactions of compounds 3 and 4 has been performed using Hirshfeld surface analysis and their associated 2D fingerprint plots.Instituto de FĂsica La Plat
A combined experimental and theoretical study of the supramolecular self-assembly of the natural benzopyran 2,2-dimethyl-3-hydroxy-6-acetyl-chromane and its isomeric benzofuran 10,11-dihydro-10-hydroxytremetone
Epoxidation of 4HMBA, the main metabolite of the medicinal plant Sencecionutans, produces an unstable epoxide eventually giving rise to a mixture of four derivatives, three of them previously reported as natural products. The epoxide product easily undergoes an intra-molecular attack of the phenolic hydroxyl against the epoxide group carbons to produce either a benzofuran or a chromane derivative. When dissolved in methanol-water mixture at room temperature the epoxide is completely solvolyzed to give the corresponding diol (hydrolysis) or vicinal hydroxyl-methoxy (methanolysis) derivative. All the compounds involved in the above reactions were characterized by IR, Raman, H NMR and UV–vis spectroscopies, and by mass spectrometry. Density functional theory (DFT) computations were used to optimize the structure conformations. The optimized structures were further subjected to a Natural Bond Orbital (NBO) and electrostatic potentials analysis. The crystal structures of the title compounds (for short, 3 and 4 respectively) were determined by X-ray diffraction methods. Compound 3 crystallizes in the triclinic P-1 space group with a = 6.4289 (6) Ă…, b = 8.7120 (6) Ă…, c = 10.952 (1) Ă…, α = 92.280 (7)°, β = 95.738 (7)°, Îł = 103.973 (7)°, and Z = 2 molecules per unit cell and 4 in the monoclinic P21/c space group with a = 11.2891 (6) Ă…, b = 9.1902 (4) Ă…, c = 12.4272 (7) Ă…. Î’ = 113.689 (7)°, and Z = 4. In 3 neighboring molecules are linked to each other by OHâ‹ŻO (keto) bonds giving rise to a polymeric structure. In 4 the OH group is a bifurcate H-bond donor. It forms a weak intra-molecular OHâ‹ŻO (furan) bond and also a much stronger inter-molecular OHâ‹ŻO (keto) bond giving rise to a zig-zag polymeric structure. A detailed analysis of the solid state molecular interactions of compounds 3 and 4 has been performed using Hirshfeld surface analysis and their associated 2D fingerprint plots.Instituto de FĂsica La Plat
Knowledge and Impact of COVID-19 on Middle-Aged and Older People Living with HIV in Lima, Peru
COVID-19 has had an unprecedented worldwide impact, and Peru has had one of the highest COVID-19 case rates despite implementation of an early strict nationwide quarantine. Repercussions on Peru's healthcare system may impact vulnerable populations, particularly people with HIV (PWH). We explored knowledge of COVID-19 and the socioeconomic and health impact of the pandemic among middle-aged and older PWH. A cross-sectional telephone survey was administered to 156 PWH age ≥40 years receiving care in one of two large HIV clinics in Lima, Peru. The majority of PWH (age 52 ± 7.7 years, 41% female, 65% completed secondary school or less) were knowledgeable regarding COVID-19 symptoms and prevention methods. Nearly half of those employed prior to the pandemic reported job loss. Female sex (unadjusted prevalence ratio [PR] 1.85 [95%CI 1.27-2.69]), low educational level (PR 1.62 [1.06-2.48]) and informal work (PR 1.58 [1.06-2.36]) were risk factors for unemployment but not in adjusted models. Increased anxiety was reported in 64% and stress in 77%. COVID-19 has had a substantial socioeconomic and mental health impact on PWH living in Lima, Peru, particularly those with lower educational levels and informal workers. Efforts are needed to ensure continued medical care and socioeconomic support of PWH in Peru
Inflammatory biomarkers and brain health indicators in children with overweight and obesity: The ActiveBrains project
INTRODUCTION: Chronic inflammation plays an important role on the pathogenesis of several cardiovascular and metabolic diseases, as well as on brain function and behaviour. The aim of the present study was to examine the associations between inflammatory biomarkers and a wide range of brain health indicators (i.e., academic performance, executive function, behavioural and emotional functioning, and brain volume) in children with overweight/obesity.
METHODS: A total of 107 children (10.0 ± 1.1 years, 41% girls) from the ActiveBrains project were included in the analysis. Five inflammatory biomarkers were analysed in plasma: white blood cell (WBC) count, interleukin-6 (IL-6), interleukin-1beta, tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP). Academic performance was assessed by Woodcock-Munoz Tests of Achievement. Executive function was assessed through the Design Fluency Test for cognitive flexibility, the Stroop test for cognitive inhibition, and the Delayed Non-Match-to-Sample task for working memory. Behavioural and emotional functioning was evaluated through the Behavior Assessment System for Children (BASC) questionnaire. Total and regional brain volume was assessed by magnetic resonance imaging.
RESULTS: IL-6 was inversely associated with adaptive skills (beta = -0.228; p = 0.030), while TNF-alpha was related to mathematics (beta = -0.198; p = 0.034). In addition, CRP was positively associated with externalizing (beta = 0.246; p = 0.046) and internalizing problems (beta = 0.234; p = 0.039), as well as the behavioural symptoms index (beta = 0.236; p = 0.047). However, these significant associations disappeared after multiple comparisons correction. Inflammatory biomarkers were not associated with executive function and total brain volumes. Regarding regional brain analyses, WBC was positively associated with gray matter volume in the left middle temporal gyrus (beta = 0.387; p < 0.001, k = 44), and CRP was positively associated with gray matter volume in the right superior temporal gyrus (beta = 0.439; p < 0.001, k = 29). Additionally, when adjusting by total brain volume, CRP was positively associated with gray matter volume in the right supplementary motor cortex (beta = 0.453; p < 0.001, k = 51). Moreover, both, IL-6 (beta = 0.366; p < 0.001, k = 81) and TNF-alpha (beta = 0.368; p < 0.001, k = 62) were positively associated with white matter volume around the right inferior frontal gyrus pars opercularis, while CRP was inversely associated with white matter volume around the left superior frontal gyrus (beta = -0.482; p < 0.001, k = 82). After adjusting by total brain volume, CRP was also inversely associated with white matter volume in 3 additional clusters (beta ranging from -0.473 to -0.404; p < 0.001, k = 87).
CONCLUSIONS: Inflammation was slightly associated with brain health (i.e., academic performance, behavioural and emotional functioning and regional brain volume) in children with overweight or obesity. Further larger longitudinal and interventional studies are warranted to elucidate the short-term and long-term effect of systemic low-grade inflammation on children's brain health
Deciphering the H-Bonding Preference on Nucleoside Molecular Recognition through Model Copper(II) Compounds
The synthetic nucleoside acyclovir is considered an outstanding model of the natural nucleoside guanosine. With the purpose of deepening on the influence and nature of non-covalent interactions regarding molecular recognition patterns, three novel Cu(II) complexes, involving acyclovir (acv) and the ligand receptor N-(2-hydroxyethyl)ethylenediamine (hen), have been synthesized and thoroughly characterized. The three novel compounds introduce none, one or two acyclovir molecules, respectively. Molecular recognition has been evaluated using single crystal X-ray diffraction. Furthermore, theoretical calculations and other physical methods such as thermogravimetric analysis, infrared and UV-Vis spectroscopy, electron paramagnetic resonance and magnetic measurements have been used. Theoretical calculations are in line with experimental results, supporting the relevance of the [metal-N7(acv) + H-bond] molecular recognition pattern. It was also shown that (hen)O-H group is used as preferred H-donor when it is found within the basal coordination plane, since the higher polarity of the terminal (hen)O-H versus the N-H group favours its implication. Otherwise, when (hen)O-H occupies the distal coordination site, (hen)N-H groups can take overThis research was funded by Agencia Estatal de InvestigaciĂłn, Ministerio de Ciencia, InnovaciĂłn y Universidades (MICIU) from Spain and co-funded with FEDER-EU (Projects No. PGC2018-102047-B-I00 and CTQ2017-85821-R); Junta de AndalucĂa (FQM-283), and University of Granada (Project ref. PPJIA2019-03)S
IntroducciĂłn a la remociĂłn selectiva de caries en patologĂa y terapĂ©utica dental I mediante la subida de contenido online a la plataforma virtual
Memoria ID2022-065. Ayudas de la Universidad de Salamanca para la innovaciĂłn docente, curso 2022-2023
Structural basis for assembly of vertical single β-barrel viruses
The vertical double beta-barrel major capsid protein (MCP) fold, fingerprint of the PRD1-adeno viral lineage, is widespread in many viruses infecting organisms across the three domains of life. The discovery of PRD1-like viruses with two MCPs challenged the known assembly principles. Here, we present the cryo-electron microscopy (cryo-EM) structures of the archaeal, halophilic, internal membrane-containing Haloarcula californiae icosahedral virus 1 (HCIV-1) and Haloarcula hispanica icosahedral virus 2 (HHIV-2) at 3.7 and 3.8 angstrom resolution, respectively. Our structures reveal proteins located beneath the morphologically distinct two- and three-tower capsomers and homopentameric membrane proteins at the vertices that orchestrate the positioning of pre-formed vertical single beta-barrel MCP heterodimers. The cryo-EM based structures together with the proteomics data provide insights into the assembly mechanism of this type of viruses and into those with membrane-less double beta-barrel MCPs.Peer reviewe
Chronic administration of the angiotensin type 2 receptor agonist C21 improves insulin sensitivity in C57BL/6 mice
The renin–angiotensin system modulates insulin action. Angiotensin type 1 receptor exerts a deleterious effect, whereas the angiotensin type 2 receptor (AT2R) appears to have beneficial effects providing protection against insulin resistance and type 2 diabetes. To further explore the role of the AT2R on insulin action and glucose homeostasis, in this study we administered C57Bl/6 mice with the synthetic agonist of the AT2R C21 for 12 weeks (1 mg/kg per day; ip). Vehicle-treated animals were used as control. Metabolic parameters, glucose, and insulin tolerance, in vivo insulin signaling in main insulin-target tissues as well as adipose tissue levels of adiponectin, and TNF-α were assessed. C21-treated animals displayed decreased glycemia together with unaltered insulinemia, increased insulin sensitivity, and increased glucose tolerance compared to nontreated controls. This was accompanied by a significant decrease in adipocytes size in epididymal adipose tissue and significant increases in both adiponectin and UCP-1 expression in this tissue. C21-treated mice showed an increase in both basal Akt and ERK1/2 phosphorylation levels in the liver, and increased insulin-stimulated Akt activation in adipose tissue. This positive modulation of insulin action induced by C21 appeared not to involve the insulin receptor. In C21-treated mice, adipose tissue and skeletal muscle became unresponsive to insulin in terms of ERK1/2 phosphorylation levels. Present data show that chronic pharmacological activation of AT2R with C21 increases insulin sensitivity in mice and indicate that the AT2R has a physiological role in the conservation of insulin action.Fil: Quiroga, Diego Tomás. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de QuĂmica BiolĂłgica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; ArgentinaFil: Muñoz, Marina Cecilia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de QuĂmica BiolĂłgica; ArgentinaFil: Gil, Carolina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de QuĂmica BiolĂłgica; ArgentinaFil: Pffeifer, Marlies. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de QuĂmica BiolĂłgica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; ArgentinaFil: Toblli, Jorge Eduardo. Hospital Aleman. Laboratorio de Medicina Experimental; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Steckelings, Ulrike M.. Southern Denmark University; DinamarcaFil: Giani, Jorge Fernando. Cedars Sinai Medical Center; Estados Unidos. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Dominici, Fernando Pablo. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de QuĂmica BiolĂłgica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; Argentin
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