Universidad de Buenos Aires
  • Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
Recent publications
Dried and milled eggplant fruit peel and calyces (PC) and mesocarp, placenta and core (Mes) were utilized as natural sources of valuable chemicals. Pectins were extracted with 0.1 M Na2CO3 (1 h; 23 °C). A high-power ultrasound (US) pretreatment (10 min net time; 12.76 W/cm2 power intensity) in 10:200 (g/mL) powder:water ratio led to the lowest solvent and energy consumptions after the subsequent 0.1 M Na2CO3 stirring, permitting the highest recoveries of uronic acid (UA) from PC and Mes (80.25 and 93.8 %, respectively). Homogalacturonans (>65 % w/w UA) of low degree of methylesterification, of acetylation, and 90,214-138,184 Da molecular weights with low polydispersity (≈1.32-1.40) were obtained. They included released ferulate (≈3.5 mg/100 g) esterified pectins. Antioxidants (caffeoylquinic acid, putrescine and spermidine derivatives, β-carotene, lutein) gave additional technological value to their thickening effect as pectins protected tryptophan, tyrosine, alkyl side chains and sulfhydryl of skim milk proteins from UV-C photo-oxidation.
Soils provide key ecosystem services and are crucial to combat climate change. Agriculture provides important ecosystem services but also causes negative environmental effects depending on agricultural management. In this regard, crop diversification is a promising sustainable land management strategy to combat soil erosion and degradation, mitigate climate change and ensure food security. Here, we assess the combined short-term effects of crop diversification and no tillage on several key soil physico-chemical parameters related to soil functioning as well as on crop yields in a rainfed almond (Prunus dulcis Mill.) orchard under semiarid Mediterranean conditions. Almond trees were inter-cropped with Capparis spinosa L. (caper) or Thymus hyemalis Lange (winter thyme) and compared with the almond monocrop system. The experimental design consisted of three plots in a randomized-block design, with three replicates for each crop management treatment (almond monocrop, almond inter-cropped with caper, and almond inter-cropped with winter thyme). Along with crop yields, the combined effects of crop diversification and no tillage on a range of soil quality and health indicators including soil physical (bulk density, aggregate stability, water retention and availability) and chemical (total and particulate organic carbon and nitrogen, ammonium and nitrate content, available macro- and micro-nutrients) properties were monitored in the topsoil and subsoil (at 0–10 and 10–30 cm depth, respectively) one and three years from establishment. Results from this study indicate that soil water retention capacity and water availability for plants were enhanced in both crop diversification systems after three years from their implementation at 0–30 cm depth. Likewise, improvements in particulate organic carbon and available N were observed in the subsoil of both crop diversifications. Crop diversification did not significantly affect the main crop yields, highlighting that crop diversification can be a promising sustainable management practice for improving soil health without compromising food security under semiarid Mediterranean conditions. Indeed, land equivalent ratios (LER) of almond trees inter-cropped with winter thyme were higher than those of their respective monocrop systems for two consecutive years, indicating that inter-cropping with aromatics can improve the productivity of rainfed woody monocrop systems under semiarid conditions. Our results emphasize the importance of selecting an appropriate secondary crop that ensures a permanent soil cover while contributes to enhance the agroecosystem productivity from the first year of establishment onwards to off-set plausible lower yields from the main crop. In this regard, preliminary assessments on soil condition and crop nutrient requirements are encouraged before designing and implementing a crop diversification in these low-input cropping systems. Likewise, long-term studies are needed to provide evidence on the stability of the production of diversified crop management, particularly in these low-input cropping systems under harsh environmental conditions.
Accumulating reports of negative impacts of tourist activities on wildlife emphasize the importance of closely monitoring focal populations. Although some effects are readily noticed, more subtle ones such as changes in physiological functions of individuals might go overlooked. Based on evidence of altered physiology associated with ecotourism on Magellanic penguins Spheniscus magellanicus, here we performed an integrated assessment using a diverse physiological toolkit together with more traditional fitness-related measures to better understand mechanisms and potential consequences. Chicks exposed to tourism showed altered immune parameters and elevated flea prevalence, reinforcing previous findings. Tourism-exposed female, but not male, chicks also showed relatively lower hematocrit and plasma protein levels, providing evidence consistent with a sex-specific response to tourist visitation. Physiological alterations detected in tourism-exposed young chicks (week 1-2) were maintained and the effect on flea infestation increased during the study period (week 4-5 of post-hatch). Despite the effects on physiology, these did not seem to translate into immediate fitness costs. No detectable tourism effects were found on brood sex ratios, chick growth and body condition, and survival until week 5-6 post-hatch. We detected no effects on reproductive output and only a marginal effect on nest survival during incubation despite previous reports of tourism-associated alterations in stress indices of adults. This disconnection could result if the physiological changes are not strong enough to impact fitness, if effects balance each other out, or if changes are part of a copying strategy. Alternatively, the physiological alterations might only show impacts later in the brooding cycle or even after chick emancipation from their parents. Our results suggest that integrative monitoring of potential anthropogenic impacts on wildlife should include evaluation of physiological mechanisms and individual-level responses in populations exposed to human activities.
In riverine floodplains, the hydrological connectivity of the aquatic habitats with the main channel is paramount for aquatic metacommunities, as it influences organism dispersal and the local environmental conditions. We assessed phytoplankton, rotifer and microcrustacean metacommunity structures and species richness along an empirical gradient of hydrological connectivity of the aquatic habitats with the main channel and compared them between high and low water levels of the main river. In addition to exploring the relative influence of hydrological connectivity, local environmental and spatial factors on metacommunity composition and the relationship between species richness and environmental and hydrological connectivity variables during both hydrological conditions. During high water levels, when high nutrient and suspended solid concentrations occurred in sites with higher hydrological connectivity and sites with opposite features and high macrophyte cover occurred in sites with lower connectivity, metacommunities showed Quasi-Nested structures (species-poor sites were subsets of species-richer sites). During low water levels, the environmental variation of the water bodies was not associated to the connectivity gradient and metacommunities showed Clementsian or Quasi-Clementsian structures: discrete groups of species replaced each other along the floodplain. Spatial factors generally were the most important for community composition; during high water levels the flood contributed to the spatial effect by transporting organisms among neighbor water sections, and during low waters it indicated dispersal limitation and/or unmeasured variables that are spatially structured. Species richness was not associated to the gradient of hydrological connectivity, no matter the hydrological condition, and showed stronger association with local factors during low than during high water levels, indicating a better match between organisms and the environment in the absence of recent floods. Our results show that the discharge regime of the river influences plankton metacommunities and their relationship with local environmental factors. This highlights the relevance of natural river water level fluctuations for aquatic communities in the present context of increasing river flow regulation worldwide.
In this work, we establish some abstract results on the perspective of the fractional Musielak–Sobolev spaces, such as: uniform convexity, Radon–Riesz property with respect to the modular function, (S+)-property, Brezis–Lieb type Lemma to the modular function and monotonicity results. Moreover, we apply the theory developed to study the existence of solutions to the following class of nonlocal problems (-Δ)Φx,ysu=f(x,u),inΩ,u=0,onRN\Ω,where N≥2, Ω⊂RN is a bounded domain with Lipschitz boundary ∂Ω and f:Ω×R→R is a Carathéodory function not necessarily satisfying the Ambrosetti–Rabinowitz condition. Such class of problems enables the presence of many particular operators, for instance, the fractional operator with variable exponent, double-phase and double-phase with variable exponent operators, anisotropic fractional p-Laplacian, among others.
Optical properties analysis is not included in biodiesel quality standards. However, it provides valuable information about biodiesel and its feedstocks. In particular, very accurate refractive index measurements can be carried out using low-cost (less than 1000 USD) and fast equipment (few seconds). Therefore, the most urgent question is to determine if the optical properties are a suitable tool for the biodiesel industry and in which applications they can currently be implemented. This work provides a comprehensive and systematic analysis of literature dealing with applications of refractive index measurements of biodiesel, its feedstocks, and its blends with other fuels. Experimental data, typical ranges of values, and mathematical models of refractive index are systematically presented and discussed, emphasizing biodiesel mixtures with diesel fossil fuel. Other applications, like transesterification monitoring, combustion, atomization, and aging are also reviewed. At the present state of knowledge, measurements of refractive index can be used to determine the proportion of diesel and biodiesel blends and monitor the transesterification reaction.
Chagas disease is an infection caused by the protozoan Trypanosoma cruzi, affecting 6-8 million people worldwide. Only two drugs are available for its treatment, having a limited efficacy and adverse side-effects. Estafietin is a sesquiterpene lactone isolated from Stevia alpina with in vitro activity against T. cruzi and low cytotoxicity against mammalian cells. The aim of this work was to predict the toxicologic profile of estafietin by in silico methods and assess its in vivo activity on a murine model of Chagas disease. Estafietin showed low toxicity according to pkCSM web tool and passed the PAINS filter from PAINS-remover web server. The treatment of infected mice with 1 mg/Kg/day of estafietin for five consecutive days administrated by intraperitoneal route significatively decreased parasitemia levels and reduced inflammatory infiltrates and myocyte damage on muscle tissue. These results suggest that estafietin had effect both on acute and chronic stages of the infection.
Psychedelics have attracted medical interest, but their effects on human brain function are incompletely understood. In a comprehensive, within-subjects, placebo-controlled design, we acquired multimodal neuroimaging [i.e., EEG-fMRI (electroencephalography-functional MRI)] data to assess the effects of intravenous (IV) N,N-Dimethyltryptamine (DMT) on brain function in 20 healthy volunteers. Simultaneous EEG-fMRI was acquired prior to, during, and after a bolus IV administration of 20 mg DMT, and, separately, placebo. At dosages consistent with the present study, DMT, a serotonin 2A receptor (5-HT2AR) agonist, induces a deeply immersive and radically altered state of consciousness. DMT is thus a useful research tool for probing the neural correlates of conscious experience. Here, fMRI results revealed robust increases in global functional connectivity (GFC), network disintegration and desegregation, and a compression of the principal cortical gradient under DMT. GFC × subjective intensity maps correlated with independent positron emission tomography (PET)-derived 5-HT2AR maps, and both overlapped with meta-analytical data implying human-specific psychological functions. Changes in major EEG-measured neurophysiological properties correlated with specific changes in various fMRI metrics, enriching our understanding of the neural basis of DMT's effects. The present findings advance on previous work by confirming a predominant action of DMT-and likely other 5-HT2AR agonist psychedelics-on the brain's transmodal association pole, i.e., the neurodevelopmentally and evolutionarily recent cortex that is associated with species-specific psychological advancements, and high expression of 5-HT2A receptors.
A method development aimed for high-throughput and automated antibody screening holds great potential for areas ranging from fundamental molecular interactions to the discovery of novel disease markers, therapeutic targets and monoclonal antibody engineering. Surface display techniques enable efficient manipulation of large molecular libraries in small volumes. Specifically, phage display appeared as a powerful technology for selecting peptides and proteins with enhanced, target-specific binding affinities. Here, we present a phage-selection microfluidic device wherein electrophoresis was performed under two orthogonal electric fields through an agarose gel functionalized with the respective antigen. This microdevice was capable of screening and sorting in a single round high affinity phage-displayed antibodies against virus glycoproteins, including Human Immunodeficiency Virus-1 (HIV-1) glycoprotein (gp120) or the Ebola Virus glycoprotein (EBOV-GP). Phages were differentially and laterally swept depending on their antigen affinity; the high affinity phages were recovered at channels proximal to the application site, whereas low affinity phages migrated distal after electrophoresis. These experiments proved that the microfluidic device specifically designed for phage-selection is rapid, sensitive and effective. Therefore, this is an efficient and cost-effective method that allowed highly controlled assay conditions for isolating and sorting high affinity ligands displayed in phages. This article is protected by copyright. All rights reserved.
Extracellular vesicles (EVs) are small, lipid-bilayer-bound particles released by cells that can contain important bioactive molecules, including lipids, RNAs, and proteins. Once released in the extracellular environment, EVs can act as messengers locally as well as to distant tissues to coordinate tissue homeostasis and systemic responses. There is a growing interest in not only understanding the physiology of EVs as signaling particles but also leveraging them as minimally invasive diagnostic and prognostic biomarkers (e.g., they can be found in biofluids) and drug-delivery vehicles. On October 30-November 2, 2022, researchers in the EV field convened for the Keystone symposium "Exosomes, Microvesicles, and Other Extracellular Vesicles" to discuss developing standardized language and methodology, new data on the basic biology of EVs and potential clinical utility, as well as novel technologies to isolate and characterize EVs.
The internal ultrastructure of the scolex and the histochemical composition of the apical glands of two South American proteocephalideans cestodes, Monticellia magna and Proteocephalus pimelodi, were described for the first time. The study included the use of scanning and transmission electron microscopy to observe the tegumental ultrastructure, and histochemical techniques to detect types of gland secretion. Two types of glands were found in the scolex of M. magna and P. pimelodi. The pattern of microtriches described for M. magna was confirmed and that of P. pimelodi was described for the first time. Also, the internal ultrastructure of the microtriches in both species was described. Indications of the presence of sensory receptors were also found in M. magna. Finally, the systematic value of the characters studied is discussed, such as the internal structure of the gladiate spinitriches and the apocrine gland of M. magna. This article is protected by copyright. All rights reserved.
We evaluated the induction of plant volatile organic compounds (VOCs) in maize after the attack of two piercing-sucking maize hoppers: the specialist Dalbulus maidis and the oligophagous Peregrinus maidis. We analyzed VOCs in plants after feeding and oviposition by females of both species. We also contrasted VOCs induced by D. maidis males with those induced by females’ infestation that comprised oviposition, to evaluate which VOC could be responsible for attracting an egg parasitoid. We quantified the damage performed by both hoppers and tested the behavioral response of the egg parasitoid Anagrus virlai to VOCs emitted by infested and healthy plants. Plants infested by D. maidis females released significantly more VOCs than the other treatments: healthy plants, plants infested by P. maidis females and plants infested by D. maidis males. β-Caryophyllene, α-bergamotene, β-farnesene and cis-3-hexenyl acetate dominated the volatile blend (46%) in plants infested by D. maidis females, while in those plants infested by P. maidis these compounds represented only 17%. Females of both hoppers inflicted a comparable amount of damage, in terms of feeding injuries and number of eggs laid. β-Caryophyllene and cis-3-hexenyl acetate were not induced in plants infested by D. maidis males, that had no oviposited eggs. Finally, females of the egg parasitoid oriented toward VOCs from plants infested by females of the specialist D. maidis, rather than those infested by the oligophagous P. maidis or those infested by D. maidis males.
In recent years, there has been great interest in developing minimally invasive strategies to enhance cognitive performance. This work aimed to evaluate the modulating effect of two interventions (stress and novelty, studies 1 and 2, respectively) on the emotional memory of adolescents. The sample included 128 participants aged between 12 and 17 years. The participants in both studies looked at 36 selected neutral and emotional pictures. Simultaneously, they rated the valence and arousal of each image (Acquisition Phase). Then, the adolescents in Study 1 performed a stressful (Experimental Group) or non-stressful (Control Group) task, while those in Study 2 watched a novel (Experimental Group) or non-novel (Control Group) video (Treatment Phase). Immediately afterward, recall and recognition were evaluated (immediate measures). A week later, free recall and recognition were tested again (deferred measures; Assessment Phase). In Study 1, the Experimental Group had better recall than the Control Group on both immediate and deferred measures, while in Study 2, the Experimental Group had better deferred recall for neutral images in comparison with the Control Group. In both studies, emotional images were more activating and better remembered than neutral ones (immediate and deferred tests). These findings suggest that the proposed interventions were beneficial in enhancing certain aspects of memory performance and could, therefore, be employed in different fields, mainly education, given that the intervention is applicable to the school-age population.
Published scientific evidence demonstrate the current spread of healthcare misinformation in the most popular social networks and unofficial communication channels. Up to 40% of the medical websites were identified reporting inappropriate information, moreover being shared more than 450,000 times in a 5-year-time frame. The phenomenon is particularly spread in infective diseases medicine, oncology and cardiovascular medicine. The present document is the result of a scientific and educational endeavor by a worldwide group of top experts who selected and analyzed the major issues and related evidence-based facts on vein and lymphatic management. A section of this work is entirely dedicated to the patients and therefore written in layman terms, with the aim of improving public vein-lymphatic awareness. The part dedicated to the medical professionals includes a revision of the current literature, summing up the statements that are fully evidence-based in venous and lymphatic disease management, and suggesting future lines of research to fulfill the still unmet needs. The document has been written following an intense digital interaction among dedicated working groups, leading to an institutional project presentation during the Universal Expo in Dubai, in the occasion of the v-WINter 2022 meeting.
Background: Implementation of international guidelines in Latin American settings requires additional considerations (i.e., values and preferences, resources, accessibility, feasibility, and impact on health equity). Objective: To provide evidence-based guidelines about diagnosis of VTE and management in children and during pregnancy. Methods: We used the GRADE ADOLOPMENT method to adapt recommendations from three American Society of Hematology, ASH, VTE guidelines (Diagnosis of VTE, VTE in Pregnancy and VTE in Pediatric population). ASH and 12 local hematology societies formed a guideline panel comprised of medical professionals from 10 countries in Latin America. Panelists prioritized 10 questions about VTE diagnosis and 18 about management in special populations that were relevant for the Latin American context. A knowledge synthesis team updated evidence reviews of health effects conducted for the original ASH guidelines and summarized information about factors specific to the Latin American context. Results: In comparison with the original guideline, there were significant changes in 2/10 diagnostic recommendations (changes in the diagnostic algorithms) and in 9/18 management recommendations (4 changed direction and 5 changed strength). Conclusions: This guideline ADOLOPMENT project highlighted the importance of contextualization of recommendations in other settings, based on differences in values, resources, feasibility and health equity impact.
Background: Patients with severe asthma may present with characteristics representing overlapping phenotypes, making them eligible for more than one class of biologic. Our aim was to describe the profile of adult patients with severe asthma eligible for both anti-IgE and anti-IL5/5R and to compare the effectiveness of both classes of treatment in real life. Methods: This was a prospective cohort study that included adult patients with severe asthma from 22 countries enrolled into the International Severe Asthma registry (ISAR) who were eligible for both anti-IgE and anti-IL5/5R. The effectiveness of anti-IgE and anti-IL5/5R was compared in a 1:1 matched cohort. Exacerbation rate was the primary effectiveness endpoint. Secondary endpoints included long-term-oral corticosteroid (LTOCS) use, asthma-related emergency room (ER) attendance and hospital admissions. Results: In the matched analysis (n=350/group), the mean annualized exacerbation rate decreased by 47.1% in the anti-IL5/5R group and 38.7% in the anti-IgE group. Patients treated with anti-IL5/5R were less likely to experience a future exacerbation (adjusted IRR 0.76; 95% CI 0.64, 0.89; p<0.001) and experienced a greater reduction in mean LTOCS dose than those treated with anti-IgE (37.44% vs 20.55% reduction; p=0.023).) There was some evidence to suggest that patients treated with anti-IL5/5R experienced fewer asthma-related hospitalizations (IRR 0.64; 95% CI 0.38, 1.08), but not ER visits (IRR 0.94, 95% CI 0.61, 1.43). Conclusions: In real life, both anti-IgE and anti-IL5/5R improve asthma outcomes in patients eligible for both biologic classes, however anti-IL5/5R was superior in terms of reducing asthma exacerbations and LTOCS use.
There are several plant below-ground biomass databases for grasslands, but the contribution from the southern hemisphere is minimal. Particularly, no study has compiled the published values of plant below-ground biomass for the temperate subhumid grasslands of South America. In these grasslands, called Río de la Plata grasslands, grazing is the most frequent disturbance. We set two objectives: 1) To compile and synthesize data of four variables: below-ground biomass, fraction of total biomass allocated below-ground, below-ground net primary productivity, and below-ground biomass turnover rate. 2) To estimate the effect of grazing exclusion on below-ground biomass by means of a meta-analysis. There are 15 studies published on six out of eight regional sub-divisions of the Río de la Plata grasslands. The most evaluated variable was below-ground biomass, followed by below-ground net primary productivity, while the other two variables were scarcely registered. Below-ground biomass in the shallow portion of the soil (0-10 cm) was on average 877 gr.m-2. Below-ground net primary productivity resulted in an average of 245 gr.m-2.y-1 (estimated using the ingrowth core method) or 560 gr.m-2.y-1 (core method). The fraction of total biomass allocated below-ground was on average 0.75. Below-ground biomass turnover rate presented an average of 2.5 years. On average, the effect of grazing exclusion on below-ground biomass depended on exclusion time. When exclusion time was shorter than or equal to three years, grazing exclusion did not affect below-ground biomass. In contrast, when exclusion time was longer than three years, grazing exclusion reduced below-ground biomass by 62% (0-10 cm depth) and by 40% (total depth). Excluding South American grasslands from the global databases may introduce some biases in the observed patterns.
The aim of this study was to assess the fatty acid percentage distribution in complex lipids of breast milk from mothers on a low docosahexaenoic acid (DHA) diet. We performed a descriptive, cross-sectional study of milk samples (n=14) collected 90 days after delivery and analyzed them using gas chromatography, thin-layer chromatography and the Fiske-Subbarow method. Complex lipid distribution was 40.70 ± 5.11% sphingomyelin (SM), 26.03 ± 5.98% phosphatidylethanolamine (PE), 21.12 ± 2.32% phosphatidylcholine, 7.94 ± 1.96% phosphatidylserine and 4.22 ± 1.25% phosphatidylinositol. Median DHA and arachidonic acid values were 0.13% (0.12; 0.18) and 0.42% (0.33; 0.53), respectively. Mean fatty acid percentage in SM and PE was as follows: palmitic acid, 34.45 ± 1.94% and 5.38 ± 0.94%; oleic acid, 16.50 ± 4.07% and 9.43 ± 4.05%; linoleic acid, 5.91 ± 4.69% and 9.05 ± 4.5%. DHA was not detectable in SM, but it was found in PE (55.33 ± 14.46). In conclusion, breast milk of mothers on a low DHA diet contained 55% DHA in PE, but no DHA in SM.
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12,345 members
Leandro Papinutti
  • Department of Biodiversity and Experimental Biology
Jeremías Incicco
  • Institute of Biological Chemistry and Physical Chemistry (IQUIFIB)
Javier Garcia-Fronti
  • Facultad de Ciencias Económicas
Daniel Gustavo Olmedo
  • Oral Pathology - School of Dentistry
Reconquista 444, , Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina