RESUMEN

In the present study, both short-range and long-range structural features of an ionic bridged silsesquioxane, specifically one containing the 1,4-diazoniabicyclo[2.2.2]octane chloride group (ISSQ), were elucidated. This ionic silsesquioxane was synthesized via direct polycondensation of a bridged organosilane precursor, without any additional functionalization step. Si-O-Si cage structures typical of Polyhedral Oligomeric Silsesquioxanes (POSS) were identified. The average interatomic distances of the POSS cages, including the open T8 cage and the T12 cage for the ISSQ, as well as the T8 cage for a commercially available pendant POSS were determined. It is the first report of the interatomic distance determination of POSS cage; achieved by using total pair distribution function G(r) values obtained through high-resolution synchrotron X-ray diffraction combined with density functional theory (DFT) calculations. The application of DFT was crucial for accurately assigning X-ray peaks and verifying structural details. Furthermore, the analysis of X-ray diffraction peaks and the examination of crystalline domains via transmission electron microscopy enabled the proposal of a hexagonal arrangement of Si-O-Si cages over long ranges within the ionic bridged silsesquioxane. This proposed arrangement highlights a distinctive structural organization that could impact the material's properties and applications.

RESUMEN

The presence of humans frequently modifies the behavior of animals, particularly their foraging patterns, compromising energetic demands. The fiddler crab Leptuca leptodactyla inhabits mangroves with high degrees of anthropogenic influence. Thus, we tested if populations living in highly anthropized mangroves respond differently from those living in more protected areas. We predict that individuals from touristy areas will be more tolerant to humans and will resume their activities sooner after disturbance. To do so, we conducted an experiment that consisted in the approach of an observer to the burrows, recording the response of individuals to the stimuli. The experiment took place in July 2022, in Ubatuba, São Paulo, Brazil. We analysed the duration and latency of various behaviors of a total of 80 adult males from two populations (high and low anthropogenic influence). Contrary to our predictions, individuals from the anthropized population were less tolerant, spending more time inside their burrows and taking longer to resume their activities. Therefore, fiddler crabs were not habituated to human presence. These results help us understand the learning process in invertebrates and their ability to select stimuli, contributing to understanding the impacts of human-wildlife interactions.

Asunto(s)

RESUMEN

Malaria is a dangerous tropical disease, with high morbidity in developing countries. The responsible parasite has developed resistance to the existing drugs; therefore, new drug delivery systems are being studied to increase efficacy by targeting hemozoin, a parasite paramagnetic metabolite. Herein, magnetic mesoporous silica (magMCM) was synthesized using iron oxide particles dispersed in the silica structure for magnetically driven behavior. The X-ray diffractogram (XRD) and Mössbauer spectra show patterns corresponding to magnetite and maghemite. Furthermore, Mössbauer spectroscopy revealed superparamagnetic behavior, attributed to single magnetic domains in particles smaller than 10 nm. Even in the presence of iron oxide particles, the hexagonal structure of MCM is clearly identified in XRD (low-angle region) and the channels are visible in TEM images. The drug chloroquine (CQ) was encapsulated by incipient wetness impregnation (magMCM-CQ). The N2 adsorption-desorption isotherms show that CQ molecules were encapsulated in the pores, without completely filling the mesopores. BET surface area values were 630 m2 g-1 (magMCM) and 467 m2 g-1 (magMCM-CQ). Encapsulated CQ exhibited rapid delivery (99% in 3 h) in buffer medium and improved solubility compared to the non-encapsulated drug, attributed to CQ encapsulation in amorphous form. The biocompatibility assessment of magMCM, magMCM-CQ, and CQ against MRC5 non-tumoral lung fibroblasts using the MTT assay after 24 h revealed no toxicity associated with magMCM. On the other hand, the non-encapsulated CQ and magMCM-CQ exhibited comparable dose-response activity, indicating a similar cytotoxic effect.

RESUMEN

Among the most important sources of ß-glucans are edible and medicinal mushrooms. These molecules are components of the cellular wall of basidiomycete fungi (mushrooms) and can be extracted even from the basidiocarp as the mycelium and its cultivation extracts or biomasses. Mushroom ß-glucans are recognized by their potential effects as immunostimulants and immunosuppressants. They are highlighted as anticholesterolemic, anti-inflammatory, adjuvant in diabetes mellitus, mycotherapy for cancer treatment, as well as adjuvants for COVID-19 vaccines. Due to their relevance, several techniques of ß-glucans extraction, purification, and analysis have already been described. Despite the previous knowledge of ß-glucans' benefits for human nutrition and health, the main information about this topic refers to the molecular identification, properties, and benefits, as well as their synthesis and action on cells. Studies on biotechnology industry applications (product development) and the registered products of ß-glucans from mushrooms are still limited and more common for feed and healthcare. In this context, this paper reviews the biotechnological production of food products containing ß-glucans from basidiomycete fungi, focusing on food enrichment, and presents a new perspective on fungi ß-glucans' use as potential immunotherapy agents. KEY POINTS: • Mushrooms' ß-glucans for product development in the biotechnology industry • Biotechnological production of food products containing mushrooms' ß-glucans • Basidiomycete fungi ß-glucans are used as potential immunotherapy agents.

Asunto(s)

RESUMEN

Despite knowledge on the therapeutic properties of fungal bio-compounds, few studies have been reported on their anti-parasitic activities. The anti-parasitic activity (APA) of mycelial extracts from seven medicinal agaricomycetous mushrooms (Polyporus lipsiensis, Ganoderma applanatum, Pleurotus ostreatus, P. flabellatus, Oudemansiella canarii, Lentinula edodes, and Pycnoporus sanguineus) against Giardia duodenalis, and identification of chemical compounds produced by mycelium P. lipsiensis mycelium, have been reported. The extracts of mycelia and fermented culture broths of tested mushroom species were evaluated against G. duodenalis by biological assays. P. lipsiensis showed the highest APA. The chemical analysis of mycelial extract of P. lipsiensis by gas chromatography-mass spectrometry (GC-MS) identified 73 molecules, including steroids, terpenes, and lipids. According to literature data, among these molecules, 11 possess APA. The present study revealed the diversity of compounds with anti-protozoal potential produced by mycelia of Agaricomycetes mushrooms, particularly P. lipsiensis against G. duodenalis.

Asunto(s)

RESUMEN

The alliance between 3D printing and nanomaterials brings versatile properties to pharmaceuticals, but few studies have explored this approach in the development of skin delivery formulations. In this study, clobetasol propionate (CP) was loaded (about 25% w/w) in mesoporous silica nanomaterial (MSN) to formulate novel bioadhesive and hydrophilic skin delivery films composed of pectin (5% w/v) and carboxymethylcellulose (5% w/v) by 3D printing. As a hydrophobic model drug, CP was encapsulated in MSN at a 3:1 (w/w) ratio, resulting in a decrease of CP crystallinity and an increase of its dissolution efficiency after 72 h (65.70 ± 6.52%) as compared to CP dispersion (40.79 ± 4.75%), explained by its partial change to an amorphous form. The CP-loaded MSN was incorporated in an innovative hydrophilic 3D-printable ink composed of carboxymethylcellulose and pectin (1:1, w/w), which showed high tensile strength (3.613 ± 0.38 N, a homogenous drug dose (0.48 ± 0.032 mg/g per film) and complete CP release after 10 h. Moreover, the presence of pectin in the ink increased the skin adhesion of the films (work of adhesion of 782 ± 105 mN·mm). Therefore, the alliance between MSN and the novel printable ink composed of carboxymethylcellulose and pectin represents a new platform for the production of 3D-printed bioadhesive films, opening a new era in the development of skin delivery systems.

RESUMEN

Abstract In this study we survey and analyze 300 projects related to marine biodiversity funded by FAPESP from 1972 to 2021, of which 46 were nested in the BIOTA Program. From a unique project in the 1970's, the number gradually increased until 2009, when BIOTA promoted a call on marine biodiversity, which led to a boost in the number of funded projects in the subsequent years. The geographical range of the projects expanded over the years and, from studies based on the coast of São Paulo State, the focus gradually shifted to broader areas of the Brazilian coast, then to other areas of the Atlantic, and eventually became global. The majority of projects focused on coastal benthic organisms living on hard-bottom. In terms of taxa, six groups accounted for about 60% of the projects (viz. Crustacea, Actinopterygii, Mollusca, Chondrichthyes, Cnidaria, and Rhodophyta), but it is observed an increase in the number of groups studied over the decades. The 300 projects refer to a set of 82 different topics, of which the top five are taxonomy, phylogeny, community, "omics", and pollution. The analyses show a long-standing effort in marine biodiversity surveys, with ongoing updated approaches regarding scope and methods. Research on strategic areas is discussed, including deep-sea and marine microbiota. Climate change and the increasing pressure of human activity on the ocean, including pollution, acidification and invasive species, are among the main challenges for the future. Projects producing and using basic research data in an integrative and transdisciplinary way offer multiple perspectives in understanding changes in ecosystem functioning and, consequently, are essential to support public policies for the conservation and sustainable use of marine biodiversity at different scales. UNESCO's Decade of Ocean (starting 2021) is a window of opportunity to strengthen marine research, to promote national and international collaboration, to build up networks involving the public and private sector, but particularly to draw society's attention to the importance of knowing marine environments and using ocean resources in a sustainable way. The advancement of ocean literacy is one of the main legacies for future generations promoted by integrated research programs such as BIOTA-FAPESP.

Resumo Neste estudo levantamos e analisamos 300 projetos relacionados à biodiversidade marinha financiados pela FAPESP entre 1972 a 2021, dos quais 46 foram realizados no Programa BIOTA. De um projeto único na década de 1970, o número foi aumentando gradativamente até 2009, quando o BIOTA promoveu uma chamada sobre biodiversidade marinha, o que impulsionou o número de projetos financiados nos anos seguintes. A abrangência geográfica dos projetos se expandiu ao longo dos anos e, a partir de estudos baseados no litoral do Estado de São Paulo, o foco gradualmente se deslocou para áreas mais amplas da costa brasileira, depois para outras áreas do Atlântico, e acabou se tornando global. A maioria dos projetos se concentrou em organismos costeiros, bentônicos, em substrato consolidado. Em termos de táxons, seis grupos responderam por cerca de 60% dos projetos (Crustacea, Actinopterygii, Mollusca, Chondrichthyes, Cnidaria e Rhodophyta), mas observa-se um aumento no número de grupos estudados ao longo das décadas. Os 300 projetos referem-se a um conjunto de 82 temas diferentes, dos quais os cinco principais são taxonomia, filogenia, comunidade, "ômicas" e poluição. As análises mostram um esforço de longa data em pesquisas de biodiversidade marinha, com abordagens atualizadas em relação ao escopo e métodos. A pesquisa em áreas estratégicas é discutida, incluindo os estudos sobre a microbiota marinha e em águas profundas. As mudanças climáticas e a crescente pressão da atividade humana sobre o oceano, incluindo poluição, acidificação e espécies invasoras, estão entre os principais desafios para o futuro. Projetos de produção e uso de dados de pesquisa básica de forma integrada e transdisciplinar oferecem múltiplas perspectivas de compreensão das mudanças no funcionamento dos ecossistemas e, consequentemente, são essenciais para subsidiar políticas públicas de conservação e uso sustentável da biodiversidade marinha em diferentes escalas. A Década do Oceano da UNESCO (a partir de 2021) é uma janela de oportunidade para fortalecer a pesquisa marinha, promover a colaboração nacional e internacional, construir redes envolvendo os setores público e privado, mas principalmente para chamar a atenção da sociedade para a importância de conhecer os ambientes marinhos e utilizar os recursos oceânicos de forma sustentável. O avanço da "alfabetização" oceânica é um dos principais legados para as gerações futuras promovidos por programas integrados de pesquisa como o BIOTA-FAPESP.

RESUMEN

O zebrafish (Danio rerio) foi descrito pela primeira vez pelo escocês e zoólogo Francis Hamilton, sendo uma das mais de 20 espécies do gênero Danio e uma das mais de 4.000 espécies dentro da ordem Cypriniformes. Na década de 80, o biólogo George Streisinger, professor do Instituto de Biologia Molecular da Universidade de Oregon - Estados Unidos é reconhecido como o fundador do modelo animal zebrafish, ele utilizou-o para explorar a base genética do desenvolvimento neural dos vertebrados, estudo esse publicado no periódico Nature. O zebrafish tem uma série de atributos que o torna um excelente modelo de pesquisa, cerca de 70% de seus genes são ortólogos aos genes humanos, sendo que destes, 82% possuem relevância a doenças humanas. Trabalhar com o zebrafish possibilita mais praticidade por ser eficiente e com baixo custo, vem substituindo cada vez mais as pesquisas realizadas com roedores. Inicialmente tornou-se popular como modelo de desenvolvimento de vertebrados, pelos embriões serem transparentes e por desenvolverem rapidamente. Na atualidade, a pesquisa está se expandindo para áreas, como farmacologia, pesquisa clínica como modelo de diversas doenças, descoberta de medicamentos e estudos toxicológicos, sendo esse último um dos campos onde se concentra uma parte significativa da produção científica brasileira. As pesquisas crescem para o aperfeiçoamento dos dados já existentes, reiterar as semelhanças com a biologia humana e para a descoberta de novos conhecimentos, que expandirão de forma positiva nosso desenvolvimento na saúde animal e humana.

RESUMEN

INTRODUCTION: Improved recovery protocols were implemented in surgical specialties over the last decade, which decreased anesthetic and surgical stress and the incidence of perioperative complications. However, these recovery protocols were introduced more slowly for cardiac surgeries. The most frequent complications in cardiac surgery are related to patient clinical status and the characteristics of the surgical procedures involved, which are becoming more varied and complex every day. The first version of the enhanced recovery program for cardiac surgery was published in 2019, but its recommendations were based on only a few studies, and scant research has evaluated its implementation. Randomized and controlled clinical trials for these protocols are scarce, so research that summarizes the results of studies with other methodological designs are useful in demonstrating their benefits in cardiovascular surgery services in Cuba and in other limited-resource settings. OBJECTIVE: Estimate the effectiveness of improved recovery protocols in the perioperative evolution of patients undergoing cardiac surgery. METHODS: We performed a systematic review and meta-analysis according to the guidelines of manual 5.1.0 for reviews of the Cochrane library. We included observational and quasi-experimental studies published from January 2015 through May 2020 that compared enhanced recovery protocols with conventional treatments in patients older than 18 years, and used a quality score to evaluate them. We used the following sources: the Cochrane Library, PubMed, LILACS, SciELO, EBSCO, Google Scholar, Web of Science, Clinical Key, ResearchGate and HINARI. The following keywords were used for the database searches in English: ERAS, protocols and cardiac surgery, enhanced recovery after cardiac surgery, ERACS, clinical pathway recovery and cardiac surgery, perioperative care and cardiac surgery. We used the following search terms for databases in Spanish: protocolos de recuperación precoz and cirugía cardiaca, protocolos de recuperación mejorada and cirugía cardiaca, cuidados perioperatorios and cirugía cardiaca, programas de recuperación precoz and cirugía cardiovascular. Methodological quality of included investigations was evaluated using the surgical research methodology scale. Meta-analyses were performed for perioperative complications, intensive care unit and hospital stays, and hospital readmission within 30 days of surgery. We calculated effect sizes of the interventions and the corresponding 95% confidence intervals. We used mean differences and confidence intervals for continuous variables, and for qualitative variables we calculated relative risk (RR). Random effects analysis was used. Heterogeneity of the studies was assessed using the Q statistic and the I2 statistic. RESULTS: We selected 15 studies (a total of 5059 patients: study group, n = 1706; control group, n = 3353). The average quality score for the 15 articles included was 18.9 (out of a maximum of 36 according to the scale) and 66.6% had a score =18. With improved recovery protocols in cardiac surgery, the incidence of perioperative complications decreased (RR = 0.73; 95% CI 0.52-0.98) as did hospital readmission within 30 days after surgery (RR = 0.51; 95% CI 95% CI: 0.31-0.86). Differences in extubation time, hospital stay and length of stay in intensive care units were less marked, but always favored the group in which the enhanced protocols were implemented. CONCLUSIONS: Improved recovery protocols in cardiac surgery increase quality of care evidenced by reductions in perioperative complications and decreased incidence of hospital readmission in the month following surgery.

Asunto(s)

RESUMEN

Fiddler crab males present a hypertrophied claw, which is used for sexual and aggressive displays, fights with competitors, and has been proposed as an important thermoregulatory organ for heat control. Two claw morphologies can be observed within fiddler crab populations: brachychelous claws (unregenerated) and leptochelous claws (regenerated). The leptochelous morphotype presents less muscle mass and longer fingers, resulting in a less advantageous weapon in fights. Considering their slender shape, we hypothesized that the leptochelous morphotype would present lower thermal inertia and be more efficient at body heat dissipation. We evaluated the role of the fiddler crabs' claw shape as a heat sink and how this influences their distribution between unshaded and shaded microhabitats. We tested in the field whether the proportion of adult male Leptuca uruguayensis with leptochelous claws was higher in unshaded microhabitats than shaded ones. In the laboratory, we tested if heat transfer between the body and claw is higher in leptochelous males than in brachychelous males. Spontaneous waving behaviour and active time above the surface were compared between both morphotypes in the field during the hottest period of the day. Leptuca uruguayensis with regenerated claws comprised more than 60% of the sampled male population of unshaded microhabitats compared to 18% in shaded microhabitats. Leptochelous males showed a mean heat transfer between body to claw 35% higher than that observed for brachychelous males. During the hottest period of the day, brachychelous males waved approximately 28% more than leptochelous males. Moreover, brachychelous males spent less time under the sediment surface since the surface temperature increased, while activity of leptochelous males was not associated with a temperature increase. Therefore, regenerated claws may be advantageous for the establishment of L. uruguayensis males in warmer and unshaded microhabitats because they are more efficient for heat loss and allow crabs to cool down, spending less time waving. Our study shows the relevant context of winners and losers in the face of climate change and highlights the importance of morphological variations in thermoregulatory structures for the occupation of thermal niches.

Asunto(s)

RESUMEN

The aim of this study was to synthesize iron magnetic nanoparticles functionalized with histidine and nickel (Fe3O4-His-Ni) to be used as support materials for oriented immobilization of His-tagged recombinant enzymes of high molecular weight, using ß-galactosidase as a model. The texture, morphology, magnetism, thermal stability, pH and temperature reaction conditions, and the kinetic parameters of the biocatalyst obtained were assessed. In addition, the operational stability of the biocatalyst in the lactose hydrolysis of cheese whey and skim milk by batch processes was also assessed. The load of 600 Uenzyme/gsupport showed the highest recovered activity value (~50%). After the immobilization process, the recombinant ß-galactosidase (HisGal) showed increased substrate affinity and greater thermal stability (~50×) compared to the free enzyme. The immobilized ß-galactosidase was employed in batch processes for lactose hydrolysis of skim milk and cheese whey, resulting in hydrolysis rates higher than 50% after 15 cycles of reuse. The support used was obtained in the present study without modifying chemical agents. The support easily recovered from the reaction medium due to its magnetic characteristics. The iron nanoparticles functionalized with histidine and nickel were efficient in the oriented immobilization of the recombinant ß-galactosidase, showing its potential application in other high-molecular-weight enzymes.

Asunto(s)

RESUMEN

In agreement with other fungal infections, immunoprotection in pulmonary paracoccidioidomycosis (PCM) is mediated by Th1/Th17 cells whereas disease progression by prevalent Th2/Th9 immunity. Treg cells play a dual role, suppressing immunity but also controlling excessive tissue inflammation. Our recent studies have demonstrated that the enzyme indoleamine 2,3 dioxygenase (IDO) and the transcription factor aryl hydrocarbon receptor (AhR) play an important role in the immunoregulation of PCM. To further evaluate the immunomodulatory activity of AhR in this fungal infection, Paracoccidioides brasiliensis infected mice were treated with two different AhR agonists, L-Kynurenin (L-Kyn) or 6-formylindole [3,2-b] carbazole (FICZ), and one AhR specific antagonist (CH223191). The disease severity and immune response of treated and untreated mice were assessed 96 hours and 2 weeks after infection. Some similar effects on host response were shared by FICZ and L-Kyn, such as the reduced fungal loads, decreased numbers of CD11c+ lung myeloid cells expressing activation markers (IA, CD40, CD80, CD86), and early increased expression of IDO and AhR. In contrast, the AhR antagonist CH223191 induced increased fungal loads, increased number of pulmonary CD11c+ leukocytes expressing activation markers, and a reduction in AhR and IDO production. While FICZ treatment promoted large increases in ILC3, L-Kyn and CH223191 significantly reduced this cell population. Each of these AhR ligands induced a characteristic adaptive immunity. The large expansion of FICZ-induced myeloid, lymphoid, and plasmacytoid dendritic cells (DCs) led to the increased expansion of all CD4+ T cell subpopulations (Th1, Th2, Th17, Th22, and Treg), but with a clear predominance of Th17 and Th22 subsets. On the other hand, L-Kyn, that preferentially activated plasmacytoid DCs, reduced Th1/Th22 development but caused a robust expansion of Treg cells. The AhR antagonist CH223191 induced a preferential expansion of myeloid DCs, reduced the number of Th1, Th22, and Treg cells, but increased Th17 differentiation. In conclusion, the present study showed that the pathogen loads and the immune response in pulmonary PCM can be modulated by AhR ligands. However, further studies are needed to define the possible use of these compounds as adjuvant therapy for this fungal infection.

Asunto(s)

RESUMEN

Invariant Natural Killer T (iNKT) cells are key players in the immunity to several pathogens; however, their involvement in the resistance to Paracoccidioides brasiliensis infection remains unknown. Using splenocytes from CD1d (CD1d-/-) and iNKT-deficient (Jα18-/-) mice, we found that iNKT cells are the innate source of IFN-γ after P. brasiliensis infection and are required to potentiate macrophage oxidative burst and control fungal growth. To determine whether iNKT cells contribute in vivo to host resistance against P. brasiliensis infection, we infected intratracheally wild-type and Jα18-/- C57BL/6 mouse strains with the virulent Pb18 isolate. iNKT cell deficiency impaired the airway acute inflammatory response, resulting in decreased airway neutrophilia and reduced IFN-γ, KC, and nitric oxide (NO) production. The deficient innate immune response of Jα18-/- mice to Pb18 infection resulted in increased fungal burden in the lungs and spleen. Besides, the activation of iNKT cells in vivo by administration of the exogenous iNKT ligand α-galactosylceramide (α-GalCer) improved host resistance to P. brasiliensis infection. Although the mechanisms responsible for this phenomenon remain to be clarified, α-GalCer treatment boosted the local inflammatory response and reduced pulmonary fungal burden. In conclusion, our study is the first evidence that iNKT cells are important for the protective immunity to P. brasiliensis infection and their activation by an exogenous ligand is sufficient to improve the host resistance to this fungal infection.

Asunto(s)

RESUMEN

A new support for the immobilization of ß-d-galactosidase from Kluyveromyces lactis was developed, consisting of mesoporous silica/titania with a chitosan coating. This support presents a high available surface area and adequate pore size for optimizing the immobilization efficiency of the enzyme and, furthermore, maintaining its activity. The obtained supported biocatalyst was applied in enzyme hydrolytic activity tests with o-NPG, showing high activity 1223 Ug-1, excellent efficiency (74%), and activity recovery (54%). Tests of lactose hydrolysis in a continuous flow reactor showed that during 14 days operation, the biocatalyst maintained full enzymatic activity. In a batch system, after 15 cycles, it retained approximately 90% of its initial catalytic activity and attained full conversion of the lactose 100% (±12%). Additionally, with the use of the mesoporous silica/titania support, the biocatalyst presented no deformation and fragmentation, in both systems, demonstrating high operational stability and appropriate properties for applications in food manufacturing.

Asunto(s)

RESUMEN

An amorphous and mesoporous silica/titania (SiTi) material was synthesized by sol-gel method and its surface was modified with gold nanoparticles (AuNP) previously stabilized in a chitosan solution. The presence of small AuNP, with diameter lower than 10 nm was confirmed by transmission electron microscopy (TEM) and UV-Vis spectroscopy. Carbon paste electrodes were prepared to test the electrochemical properties by using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in [Fe(CN)6]3-/4- solution probe whereby the material silica-titania/gold nanoparticles (SiTi/AuNP) showed a huge improvement in the redox peak current and low charge transfer resistance. This electrode presented a good response for both norepinephrine and dopamine by means of square wave voltammetry (SWV) measurements; great sensitivity for both analytes, in an extensive linear range, was obtained. The limits of detection were 0.35 µmol L-1 and 0.57 µmol L-1 for norepinephrine and dopamine, respectively. Additionally, this electrode showed high selectivity for both analytes and it was applied in the simultaneous determination of norepinephrine and dopamine. The sensor was also tested in simulated biological fluids presenting a good recovery. The SWV electrochemical response of norepinephrine was also investigated in the presence of possible interferers such as uric acid, ascorbic acid and glucose and there was no significant interference. The prepared electrode also exhibits good reproducibility for norepinephrine detection, with relative standard deviation of 5.19%.

Asunto(s)

RESUMEN

Natural antiparasitic agents are used as a strategy for advances in the treatment of neglected tropical diseases (NTDs), such as giardiasis. The present paper identified the compounds produced by Ganoderma lipsiense mycelium grown in submerged fermentation and investigated the antigiardial activity potential of extracts in vitro. G. lipsiense mycelium crude extract (CE) was obtained by the maceration process and after purification in column, thirty compounds were identified by gas chromatography - mass spectrometry (GC-MS) in hexane sub-fraction (HSF). To determine the antigiardial potential, different parts of the purified CE have been evaluated, where hexane (HEXf) and dichloromethane (DCMf) fractions showed in vitro reduction levels higher than 90% of the Giardia duodenalis trophozoites at 100 µg mL-1. This antigiardial activity was investigated aiming to explore the possibility of G. lipsiense mycelium extract as a novel antigiardial compound to the treatment of human giardiasis.

Asunto(s)

RESUMEN

We investigated the changes in the physical structure of cellulose recovered from soybean and rice hulls treated with the ionic liquids 1-butyl-3-methylimidazolium chloride ([bmim][Cl]) and 1-butyl-3-methylimidazolium acetate ([bmim][Ac]). The characterization was carried out by a combination of thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Regenerated cellulose from soybean hull showed loss of crystallinity and high structural disruption caused by both ionic liquid treatments as compared to the untreated material. In contrast, rice hull presented only a small structural disruption when treated with [bmim][Ac] and was practically unaffected by [bmim][Cl], showing that this biomass residue is recalcitrance towards physico-chemical treatments, possibly as a consequence of its high composition content in silica. These results suggest the use of soybean hull as a substrate to be treated with ionic liquids in the preparation of lignocellulosic hydrolysates to be used in second-generation ethanol production, whereas other methods should be considered to treat rice hull biomass.

Asunto(s)

RESUMEN

Genus Arachis comprises 82 species distributed into nine taxonomic sections. Most Arachis species are wild and those from Arachis section have been evaluated for many traits, since they can be used in peanut breeding. Most of the remaining species have been neglected and understudied. Recently, resveratrol content and expression of a resveratrol synthase gene were analyzed in wild Arachis species. Our aim was to expand the knowledge about resveratrol in Arachis, analyzing species from five sections and evaluating the expression of a resveratrol synthase (RS) gene responsive to ultraviolet light (UV) along the time. In a first experiment, the resveratrol content after UV induction was analyzed on detached leaves of 12 species from five sections. Variation was observed among species and accessions of the same species. The highest contents were found in A. lignosa (843.9 µg/g) and A. triseminata (745.4 µg/g). In a second experiment, RS expression and resveratrol content in four species and one synthetic amphidiploid were analyzed at 0, 7, 15 and 24 h pos induction (hpi) with UV. In most genotypes, the highest RS expression level was at 0 hpi, whereas the highest resveratrol content was at 15 hpi. Our results suggested that resveratrol is ubiquitously present in the genus Arachis with different capacities of synthesis among species and accessions in response to ultraviolet treatment. Presence of resveratrol in wild Arachis species adds new value to these genetic resources.

Asunto(s)

RESUMEN

A mesoporous, magnetic, and hydrophobic material was designed step by step to act as a support for lipase immobilization. Its pore size (8.0 nm) is compatible with the size of lipase from Thermomyces lanuginosus (TLL), and its hydrophobic surface (contact angle of a water drop = 125°) was planned to interact with lipase on its interfacially activated form (open conformation). The presence of magnetite particles provides magnetic retrieval of the material and enables recyclability of the biocatalysts. Regarding immobilization parameters, the hydrophobic support was tested in comparison to the unmodified hydrophilic support in phosphate buffer solution (50 mmol L-1, pH 7.5) at 25 °C. Hydrophobicity was found to be critical for the amount of immobilized TLL (immobilization yield of 97% versus 36% for the hydrophilic support), whereas the hydrophilic support favors the native conformational state and substrate access to the enzyme's catalytic site (specific activity of 5.7 versus 4.7 U g-1 for the hydrophobic support, even when it has higher TLL content). Therefore, the hydrophobic support immobilizes higher amounts of TLL and the hydrophilic support keeps the enzyme hyperactivated. Last, due to the stronger interactions of TLL with hydrophobic surfaces, the hydrophobic support offers better preservation of enzyme activity in repeated cycles (76% of activity retained after three cycles versus 50% for the hydrophilic support).

Asunto(s)

RESUMEN

The prior residence effect consists of a higher probability of territory owners to win a fight against intruders, as observed in several territorial species across animal kingdom. However, in investigations on territorial behavior, intruder traits have been assumed as fixed. Thus, we used a territorial species as experimental model to evaluate the effect of intruder traits on aggressive behavior of territory owners. During fights staged between territory owners and intruders, intruder traits, linked with visual signals of social status (dominant-subordinate position), modulate fighting behavior of territory owners, but prior residence effect still occurred. Intruder traits must be addressed more effectively for improving the theoretical understanding of territoriality.

Asunto(s)