Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 37
Filter
Add more filters










Publication year range
1.
Zootaxa ; 5264(3): 405-417, 2023 Apr 14.
Article in English | MEDLINE | ID: mdl-37518040

ABSTRACT

Microlia Casey is a genus of small rove beetles from the New World and Australasia. Many species are recorded to be associated with the flowers of Cucurbitaceae, Solanaceae, Asteraceae, and Monimiaceae. In this work, a new species from Brazil associated with flowers of Cayaponia (Cucurbitaceae), Microlia cayaponia Zilberman & Pires-Silva sp. nov., is described and illustrated. Aspects of its natural history are also investigated, with insights on foraging, reproduction, and the supposed impact on the plant and pollinator's fitness.


Subject(s)
Coleoptera , Cucurbitaceae , Animals , Brazil , Pollen , Reproduction
2.
Neotrop Entomol ; 52(5): 802-813, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37495766

ABSTRACT

Numerous staphylinid species can be found in termite nests. While the distributional range of termite hosts has been well studied, the same cannot be said for their associated fauna. There is a lack of comprehensive sampling even in areas where termite fauna has been well-sampled. In recent surveys in Southeastern Brazil, we collected a new species of termitophilous rove beetle from the tribe Termitohospitini (Aleocharinae): Termitosocius boraceiensis sp. nov., is herein described. The new species is the first termitophile found in Boracéia, SP, Brazil, even with decades of termite sampling in the place. Additionally, we discuss the diversity and description rate of neotropical Termitohospitini, and investigate the potential of cospeciation between termites and their termitophilous beetles on the Emerson-Kistner principle. Our findings suggest that the neotropical Termitohospitini may be more diverse than previously believed and that Termitosocius species are present in host species that are geographically separated, implying a cospeciation scenario. Additional sampling is required to fully comprehend the relationships between termitophiles and their termite hosts. The outcomes of this study provide new insights into the undersampling scenario and possibly cospeciation between termites and their termitophiles in the Neotropical region.


Subject(s)
Coleoptera , Isoptera , Animals , Brazil , Host Specificity , Surveys and Questionnaires
3.
Int J Mol Sci ; 24(8)2023 Apr 15.
Article in English | MEDLINE | ID: mdl-37108479

ABSTRACT

Molecular dynamics simulations employing the all-atom optimized potential for liquid simulations (OPLS-AA) force field were performed for determining self-diffusion coefficients (D11) of ethanol and tracer diffusion coefficients (D12) of solutes in ethanol at several temperature and pressure conditions. For simulations employing the original OPLS-AA diameter of ethanol's oxygen atom (σOH), calculated and experimental diffusivities of protic solutes differed by more than 25%. To correct this behavior, the σOH was reoptimized using the experimental D12 of quercetin and of gallic acid in liquid ethanol as benchmarks. A substantial improvement of the calculated diffusivities was found by changing σOH from its original value (0.312 nm) to 0.306 nm, with average absolute relative deviations (AARD) of 3.71% and 4.59% for quercetin and gallic acid, respectively. The new σOH value was further tested by computing D12 of ibuprofen and butan-1-ol in liquid ethanol with AARDs of 1.55% and 4.81%, respectively. A significant improvement was also obtained for the D11 of ethanol with AARD = 3.51%. It was also demonstrated that in the case of diffusion coefficients of non-polar solutes in ethanol, the original σOH=0.312 nm should be used for better agreement with experiment. If equilibrium properties such as enthalpy of vaporization and density are estimated, the original diameter should be once again adopted.


Subject(s)
Ethanol , Quercetin , Molecular Dynamics Simulation , Thermodynamics , Temperature
4.
Zootaxa ; 5230(4): 467-477, 2023 Jan 24.
Article in English | MEDLINE | ID: mdl-37044833

ABSTRACT

The tribe Placusini (Coleoptera: Staphylinidae) consists five genera with worldwide distribution. Despite great morphological diversity, the species are easily recognized by their 4-4-5 tarsal formula and the two-articulated labial palpi, along with a broad and rounded ligula. Several synapomorphies proposed by earlier authors, both for larvae and adults, have led to the conclusion that the tribe now is considered monophyletic within Aleocharinae. Herein, a new genus and species of Placusini from Brazil is described and illustrated. Euryachen seuzei gen. et sp. nov. presents all the proposed synapomorphies for the tribe, in addition to unique characters. An updated key for the genera in Placusini is also provided.


Subject(s)
Coleoptera , Animals , Brazil , Animal Distribution , Larva
5.
Zootaxa ; 5239(2): 247-264, 2023 Feb 09.
Article in English | MEDLINE | ID: mdl-37045100

ABSTRACT

Xenogaster Wasmann, 1891, is a Neotropical beetle genus of termitophilous beetles, comprising ten species disjunctly distributed. During the study of specimens of the Museu de Zoologia da Universidade de São Paulo, collected during expeditions to Southeastern Brazil, two new species were discovered. Xenogaster pseudonuda sp. nov. and X. kymopoleia sp. nov., are described and illustrated. A discussion is provided regarding the tarsal condition in Xenogaster and the coeloconic sensilla on antennomere III, constituting the first record for the subtribe Termitogastrina.


Subject(s)
Coleoptera , Expeditions , Animals , Brazil , Animal Distribution
6.
Sensors (Basel) ; 23(4)2023 Feb 17.
Article in English | MEDLINE | ID: mdl-36850872

ABSTRACT

Currently, few experimental methods exist that enable the mechanical characterization of adhesives under high strain rates. One such method is the Split Hopkinson Bar (SHB) test. The mechanical characterization of adhesives is performed using different specimen configurations, such as Single Lap Joint (SLJ) specimens. A gripping system, attached to the bars through threading, was conceived to enable the testing of SLJs. An optimization study for selecting the best thread was performed, analyzing the thread type, the nominal diameter, and the thread pitch. Afterwards, the gripping system geometry was numerically evaluated. The optimal threaded connection for the specimen consists of a trapezoidal thread with a 14 mm diameter and a 2 mm thread pitch. To validate the gripping system, the load-displacement (P-δ) curve of an SLJ, which was simulated as if it were tested on the SHB apparatus, was compared with an analogous curve from a validated drop-weight test numerical model.

7.
Zootaxa ; 5336(3): 424-432, 2023 Aug 23.
Article in English | MEDLINE | ID: mdl-38221085

ABSTRACT

Termitophilous rove beetles in Australia encompass diverse genera and species from several tribes in Aleocharinae. While some taxa have been well-documented, others remain poorly known due to the scarcity of available material. The existing knowledge of Austrospirachtha Watson for instance, is based solely on Austrospirachtha mimetes, described from two specimens collected in an old termite mound. The genus is known for its highly developed physogastry and potential mimicry adaptations. Herein, we present the description of a new species, Austrospirachtha carrijoi sp. nov., representing the second known species for the genus.


Subject(s)
Coleoptera , Isoptera , Animals , Animal Distribution , Australia
8.
Naturwissenschaften ; 109(6): 53, 2022 Nov 02.
Article in English | MEDLINE | ID: mdl-36322254

ABSTRACT

Among the termite-associated fauna, rove beetles of the subfamily Aleocharinae are distinguished by exhibiting the majority of convergent evolutions to this lifestyle. This phenomenon known as termitophily brings many advantages, including the care of nestmates and the exploitation of resources. While some mechanisms that ensure the integration of the termitophiles into the colony are well known, such as chemical mimicry, others remain unclear. In this article, we discuss the importance of termitophile behavior for the stability of interactions within termite colonies. We address behavioral mimicry as an important integration mechanism between termitophiles and termites. We compare both termitophile's and termite's behavioral repertoires and found no significant differences between them, suggesting that social parasites can mislead their host through their behavior in order to exploit the colony and to keep positive interactions with their hosts. In addition, we describe a new species of termitophile rove beetle from a highland humid forest in northeastern Brazil: Thyreoxenus alakazam sp. nov., with detailed illustrations and comments on post-imaginal growth in the context of our hypothesis of the post-imago phenotype, known as stenogastry, as a recapitulation of ancestral conditions in physogastric rove beetles.


Subject(s)
Coleoptera , Isoptera , Animals , Brazil , Animal Distribution , Biological Evolution
9.
Materials (Basel) ; 15(18)2022 Sep 15.
Article in English | MEDLINE | ID: mdl-36143725

ABSTRACT

In this work, a simple two-parameters correlation based on the Rice and Gray, Lennard-Jones, and Stockmayer theories was devised for the calculation of binary diffusion coefficients (D12) of any type of solutes at infinite dilution in polar and non-polar solvents. This equation can be relevant for systems with polar solvents, since most models in the literature fail when strong intermolecular forces predominate in solution. The new correlation embodies the Stockmayer potential without requiring the dipole moments of any component, which significantly enlarges its application. It was validated with the largest D12 database of polar and non-polar dense systems, with 8812 data points (NDP) spanning 553 systems, of which 133 have water as solvent (NDP = 1266), 89 contain polar solvents excluding water (NDP = 1405), 177 have supercritical carbon dioxide (SC-CO2) as solvent (NDP = 5028), and 154 have non-polar or weakly polar solvents excluding SC-CO2 (NDP = 1113). Overall, the model achieved an average deviation of only 3.43%, with accurate and unbiased behavior even for polar systems.

10.
Biomolecules ; 12(9)2022 09 12.
Article in English | MEDLINE | ID: mdl-36139123

ABSTRACT

Spent coffee grounds (SCGs) are a promising substrate that can be valorized by biotechnological processes, such as for short-chain organic acid (SCOA) production, but their complex structure implies the application of a pretreatment step to increase their biodegradability. Physicochemical pretreatments are widely studied but have multiple drawbacks. An alternative is the application of biological pretreatments that include using fungi Trametes versicolor and Paecilomyces variotii that naturally can degrade complex substrates such as SCGs. This study intended to compare acidic and basic hydrolysis and supercritical CO2 extraction with the application of these fungi. The highest concentration of SCOAs, 2.52 gCOD/L, was achieved after the acidification of SCGs pretreated with acid hydrolysis, but a very similar result, 2.44 gCOD/L, was obtained after submerged fermentation of SCGs by T. versicolor. This pretreatment also resulted in the best acidification degree, 48%, a very promising result compared to the 13% obtained with the control, untreated SCGs, highlighting the potential of biological pretreatments.


Subject(s)
Coffee , Trametes , Carbon Dioxide/metabolism , Coffee/chemistry , Fermentation , Hydrolysis , Trametes/metabolism
11.
Bioengineering (Basel) ; 9(8)2022 Aug 03.
Article in English | MEDLINE | ID: mdl-36004887

ABSTRACT

Acidogenic fermentation (AF) is often applied to wastes to produce short-chain organic acids (SCOAs)-molecules with applications in many industries. Spent coffee grounds (SCGs) are a residue from the coffee industry that is rich in carbohydrates, having the potential to be valorized by this process. However, given the recalcitrant nature of this waste, the addition of a pretreatment step can significantly improve AF. In this work, several pretreatment strategies were applied to SCGs (acidic hydrolysis, basic hydrolysis, hydrothermal, microwave, ultrasounds, and supercritical CO2 extraction), evaluated in terms of sugar and inhibitors release, and used in AF. Despite the low yields of sugar extracted, almost all pretreatments increased SCOAs production. Milder extraction conditions also resulted in lower concentrations of inhibitory compounds and, consequently, in a higher concentration of SCOAs. The best results were obtained with acidic hydrolysis of 5%, leading to a production of 1.33 gSCOAs/L, an increase of 185% compared with untreated SCGs.

12.
Materials (Basel) ; 15(6)2022 Mar 09.
Article in English | MEDLINE | ID: mdl-35329479

ABSTRACT

Increasing awareness regarding fossil fuel dependence, waste valorization, and greenhouse gas emissions have prompted the emergence of new solutions for numerous markets over the last decades. The tire industry is no exception to this, with a global production of more than 1.5 billion tires per year raising environmental concerns about their end-of-life recycling or disposal. Pyrolysis enables the recovery of both energy and material from end-of-life tires, yielding valuable gas, liquid, and solid fractions. The latter, known as recovered carbon black (rCB), has been extensively researched in the last few years to ensure its quality for market applications. These studies have shown that rCB quality depends on the feedstock composition and pyrolysis conditions such as type of reactor, temperature range, heating rate, and residence time. Recent developments of activation and demineralization techniques target the production of rCB with specific chemical, physical, and morphological properties for singular applications. The automotive industry, which is the highest consumer of carbon black, has set specific targets to incorporate recycled materials (such as rCB) following the principles of sustainability and a circular economy. This review summarizes the pyrolysis of end-of-life tires for the production of syngas, oil, and rCB, focusing on the process conditions and product yield and composition. A further analysis of the characteristics of the solid material is performed, including their influence on the rCB application as a substitute of commercial CB in the tire industry. Purification and modification post-treatment processes for rCB upgrading are also inspected.

13.
Mar Biotechnol (NY) ; 24(1): 40-54, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34855032

ABSTRACT

Aurantiochytrium sp. is an emerging alternative source of polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA), and squalene, playing an important role in the phasing out of traditional fish sources for these compounds. Novel lipid extraction techniques with a focus on sustainability and low environmental footprint are being developed for this organism, but the exploration of other added-value compounds within it is still very limited. In this work, a combination of novel green extraction techniques (high hydrostatic pressure extraction (HPE) and supercritical fluid extraction (SFE)) and traditional techniques (organic solvent Soxhlet extraction and hydrodistillation (HD)) was used to obtain lipophilic extracts of Aurantiochytrium sp., which were then screened for antioxidant (DPPH radical reduction capacity and ferric-reducing antioxidant potential (FRAP) assays), lipid oxidation protection, antimicrobial, anti-aging enzyme inhibition (collagenase, elastase and hyaluronidase), and anti-inflammatory (inhibition of NO production) activities. The screening revealed promising extracts in nearly all categories of biological activity tested, with only the enzymatic inhibition being low in all extracts. Powerful lipid oxidation protection and anti-inflammatory activity were observed in most SFE samples. Ethanolic HPEs inhibited both lipid oxidation reactions and microbial growth. The HD extract demonstrated high antioxidant, antimicrobial, and anti-inflammatory activities making, it a major contender for further studies aiming at the valorization of Aurantiochytrium sp. Taken together, this study presents compelling evidence of the bioactive potential of Aurantiochytrium sp. and encourages further exploration of its composition and application.


Subject(s)
Chromatography, Supercritical Fluid , Stramenopiles , Animals , Antioxidants/chemistry , Antioxidants/pharmacology , Chromatography, Supercritical Fluid/methods , Plant Extracts/chemistry , Solvents
14.
Zootaxa ; 5194(1): 122-132, 2022 Oct 04.
Article in English | MEDLINE | ID: mdl-37045341

ABSTRACT

The subtribe Termitonannina consists of eight genera of termitophilous rove beetles from the Neotropical region associated with termites of the subfamilies Apicotermitinae, Nasutitermitinae, Syntermitinae, and Termitinae. A new genus, Dilacera Zilberman & Pires-Silva gen. nov. is established, and a new species, Dilacera exokosmos Zilberman & Pires-Silva gen. et sp. nov., from the Brazilian Amazon, is described and illustrated, with its morphological distinctiveness within the subtribe, discussed. Remarks on the host relationship with Uncitermes teevani (Emerson, 1925) (Termitidae: Syntermitinae) are provided, with an updated checklist of termitophilous species and their associated hosts within Termitonannina, including a discussion on confusing nomenclatural takes on termite hosts.


Subject(s)
Coleoptera , Isoptera , Animals , Coleoptera/anatomy & histology
15.
Foods ; 10(12)2021 Dec 09.
Article in English | MEDLINE | ID: mdl-34945609

ABSTRACT

While Aurantiochytrium sp. is an increasingly popular source of polyunsaturated fatty acids (PUFAs), its extraction generates high amounts of waste, including the spent, defatted residue. The composition and bioactivities of this by-product could prove to be a major part of the sustainable valorisation of this organism within the framework of a circular economy. In this study, the defatted biomass of commercial Aurantiochytrium sp. was nutritionally characterised, and its amino acid profile was detailed. Additionally, the antioxidant and prebiotic potentials of an enzymatically digested sample of defatted Aurantiochytrium sp. were evaluated under a set of miniaturised in vitro assays. The nutritional profile of the spent Aurantiochytrium biomass revealed a protein and dietary-fibre rich product, with values reaching 26.7% and 31.0% for each, respectively. It also held high concentrations of glutamic and aspartic acid, as well as a favourable lysine/arginine ratio of 3.73. The digested samples demonstrated significant Weissela cibaria and Bifidobacterium bifidum growth-enhancing potential. Residual ferric reducing antioxidant power (FRAP) activity was likely attributed to antioxidant amino acids or peptides. The study demonstrated that some of the nutritional and functional potential that reside in the defatted Aurantiochytrium sp. waste encourages additional studies and the development of food supplements employing this resource's by-products under a biorefinery framework.

16.
Environ Sci Pollut Res Int ; 28(23): 30255-30266, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33586107

ABSTRACT

Mercury is a very toxic metal that persists and accumulates in the living organisms present in the aquatic systems and its elimination is an urgent need. Two green (Ulva intestinalis and Ulva lactuca), brown (Fucus spiralis and Fucus vesiculosus), and red (Gracilaria sp. and Osmundea pinnatifida) marine macroalgae were tested for mercury removal from saline waters. The ability of each species was evaluated to the initial mercury concentrations of 50, 200, and 500 µg dm-3 along 72 h. In general, all species exhibited good performances, removing 80.9-99.9% from solutions with 50 µg dm-3, 79.3-98.6% from solutions with 200 µg dm-3, and 69.8-97.7% from solutions containing 500 µg dm-3 of mercury. Among the macroalgae, Ulva intestinalis showed the highest affinity to mercury and it presented an uptake ability up to 1888 µg g-1 of Hg(II) and bioconcentration factors up to 3823, which proved its promising potential on Hg removal.


Subject(s)
Mercury , Seaweed , Ulva , Water Pollutants, Chemical , Bioaccumulation , Saline Waters , Water Pollutants, Chemical/analysis
17.
Materials (Basel) ; 14(3)2021 Jan 23.
Article in English | MEDLINE | ID: mdl-33498723

ABSTRACT

Experimental diffusivities are scarcely available, though their knowledge is essential to model rate-controlled processes. In this work various machine learning models to estimate diffusivities in polar and nonpolar solvents (except water and supercritical CO2) were developed. Such models were trained on a database of 90 polar systems (1431 points) and 154 nonpolar systems (1129 points) with data on 20 properties. Five machine learning algorithms were evaluated: multilinear regression, k-nearest neighbors, decision tree, and two ensemble methods (random forest and gradient boosted). For both polar and nonpolar data, the best results were found using the gradient boosted algorithm. The model for polar systems contains 6 variables/parameters (temperature, solvent viscosity, solute molar mass, solute critical pressure, solvent molar mass, and solvent Lennard-Jones energy constant) and showed an average deviation (AARD) of 5.07%. The nonpolar model requires five variables/parameters (the same of polar systems except the Lennard-Jones constant) and presents AARD = 5.86%. These results were compared with four classic models, including the 2-parameter correlation of Magalhães et al. (AARD = 5.19/6.19% for polar/nonpolar) and the predictive Wilke-Chang equation (AARD = 40.92/29.19%). Nonetheless Magalhães et al. requires two parameters per system that must be previously fitted to data. The developed models are coded and provided as command line program.

18.
3D Print Addit Manuf ; 8(4): 263-270, 2021 Aug 01.
Article in English | MEDLINE | ID: mdl-36654833

ABSTRACT

Defect detection in additive manufacturing (AM) is of paramount importance to improve the reliability of products. Nondestructive testing is not yet widely used for defect detection. The main challenges are a lack of standards and methods, the types and location of defects, and the complex geometry of many parts. During selective laser melting (SLM), several types of defects can occur such as porosity, cracking, and lack of fusion. In this study, several nondestructive tests were conducted in a highly complex shaped part in AISI 316L stainless steel with real defects manufactured by SLM. Two additional artificial defects (one horizontal and one flat bottom hole) were produced and the defect detectability was evaluated. The techniques used were as follows: dye penetrant, infrared thermography, immersion ultrasonic, eddy current, and X-ray microcomputed tomography to assess different types of defects in the as-built part. We conclude that no single technique can detect every type of defect, although multiple techniques provide complementary and redundant information to critically evaluate the integrity of the parts. This approach is fundamental for improving the reliability of defect detection, which will help expand the potential for using AM to produce parts for critical structural applications.

19.
Materials (Basel) ; 14(1)2020 Dec 22.
Article in English | MEDLINE | ID: mdl-33375164

ABSTRACT

The removal of the hazardous Hg2+ from aqueous solutions was studied by ion exchange using titanosilicate in sodium form (Na-ETS-4). Isothermal batch experiments at fixed pH were performed to measure equilibrium and kinetic data, considering two very distinct situations to assess the influence of competition effects: (i) the counter ions initially in solution are Na+ and Hg2+ (both are exchangeable); (ii) the initial counter ions in solution are tetrapropylammonium (TPA+) and Hg2+ (only Hg2+ is exchangeable, since TPA+ is larger than the ETS-4 micropores). The results confirmed that ETS-4 is highly selective for Hg2+, with more than 90% of the mercury being exchanged from the fluid phase. The final equilibrium attained under the presence of TPA+ or Na+ in solution was very similar, however, the Hg2+/Na+/ETS-4 system in the presence of Na+ required more 100 h to reach equilibrium than in the presence of TPA+. The Hg2+/Na+/ETS-4 system was modelled and analyzed in terms of equilibrium (mass action law) and mass transfer (Maxwell-Stefan (MS) formalism). Concerning equilibrium, no major deviations from ideality were found in the range of studied concentrations. On the other hand, the MS based model described successfully (average deviation of 5.81%) all kinetic curves of mercury removal.

20.
Sci Total Environ ; 724: 138133, 2020 Jul 01.
Article in English | MEDLINE | ID: mdl-32268287

ABSTRACT

Mercury (Hg) removal by six different living marine macroalgae, namely, Ulva intestinalis, Ulva lactuca, Fucus spiralis, Fucus vesiculosus, Gracilaria sp., and Osmundea pinnatifida was investigated in mono and multi-contamination scenarios. All macroalgae were tested under the same experimental conditions, evaluating the competition effects with all elements at the same initial molar concentration of 1 µmol dm-3. The presence of the main potentially toxic elements (Cd, Cr, Cu, Ni, and Pb) and rare earth elements (La, Ce, Pr, Nd, Eu, Gd, Tb, and Y) has not affected the removal of Hg. Characterizations of the macroalgae by FTIR before and after the biosorption/bioaccumulation assays suggest that Hg was mainly linked to sulfur-functional groups, while the removal of other elements was related with other functional groups. The mechanisms involved point to biosorption of Hg on the macroalgae surface followed by possible incorporation of this metal into the macroalgae by metabolically active processes. Globally, the green macroalgae (Ulva intestinalis, Ulva lactuca) showed the best performances for Hg, potential toxic elements and rare earth elements removal from synthetic seawater spiked with 1 µmol dm-3 of each element, at room temperature and pH 8.5.


Subject(s)
Mercury , Metals, Rare Earth , Seaweed , Water Pollutants, Chemical/analysis , Water Pollution
SELECTION OF CITATIONS
SEARCH DETAIL
...