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Pterocaulon polystachyum is a species of pharmacological interest for providing volatile and non-volatile extracts with antifungal and amebicidal properties. The biological activities of non-volatile extracts may be related to the presence of coumarins, a promising group of secondary metabolites. In the present study, leaves and inflorescences previously used for the extraction of essential oils instead of being disposed of were subjected to extraction with supercritical CO2 after pretreatment with microwaves. An experimental design was followed to seek the best extraction condition with the objective function being the maximum total extract. Pressure and temperature were statistically significant factors, and the optimal extraction condition was 240 bar, 60 °C, and pretreatment at 30 °C. The applied mathematical models showed good adherence to the experimental data. The extracts obtained by supercritical CO2 were analyzed and the presence of coumarins was confirmed. The extract investigated for cytotoxicity against bladder tumor cells (T24) exhibited significant reduction in cell viability at concentrations between 6 and 12 μg/mL. The introduction of green technology, supercritical extraction, in the exploration of P. polystachyum as a source of coumarins represents a paradigm shift with regard to previous studies carried out with this species, which used organic solvents. Furthermore, the concept of circular bioeconomy was applied, i.e., the raw material used was the residue of a steam-distillation process. Therefore, the approach used here is in line with the sustainable exploitation of native plants to obtain extracts rich in coumarins with cytotoxic potential against cancer cells.

Background/Objectives: Degradation by physical and chemical agents affects the properties of essential oils; therefore, this study aimed to protect the volatile compounds present in essential oils through biopolymer encapsulation. Methods: The Achyrocline satureioides (Lam) DC. essential oil was obtained by steam distillation at 2.5 bar. The nano-sized physical coating of the active oil core resulted in an optimal polymer/oil ratio of 1:3 and particle diameter of 178 nm. The particle morphology was evaluated using scanning electron microscopy and transmission electron microscopy. The inclusion of the essential oil in the polymer was confirmed using thermogravimetric analysis. Results: The pH of the formulation remained stable for 90 days, and controlled release and encapsulation efficiencies were evaluated. Formulations were evaluated using the perfumery radar technique, which indicated a predominantly woody profile. The diffusion of fragrant compounds in the air was assessed over time and mathematically modeled. Conclusions: The produced nanostructures were efficient for the controlled release of volatile compounds from the essential oil of Achyrocline satureioides.

Nitrogen (N) availability plays a crucial role in plant development. However, studies indicate that the pathosystem of pathogenic fungi, such as Bipolaris maydis, which causes Southern Corn Leaf Blight (SCLB) in popcorn, interacts with N availability. Therefore, this study seeks to select popcorn inbred lines (ILs), considering contrasting environments regarding N availability (low N—LN and optimal N—ON). For this, 90 ILs from 16 populations from tropical and temperate climates from South America were evaluated in five experiments using a randomized complete block design (three replications), with four common controls. From the tests, the level of severity of the ILs to SCLB was evaluated. Three trials showed greater severity in ON, one trial had higher severity in LN, and one trial did not show significant differences. However, the genotype x nitrogen level (GxN) interaction was always present. Of the 90 ILs, 73 showed resistance in both N levels, three only in LN, and four only in ON, while 10 were susceptible in both environments. On average, the lines were more susceptible in ON, and the observed GxN interactions indicate that there is a distinct behavior of the genotypes regarding the response to N in the soil, which reinforces the importance of selection in contrasting environments.

The Great American Biotic Interchange (GABI) was greatly influenced by the completion of the Isthmus of Panama and impacted the composition of modern faunal assemblages in the Americas. However, the contribution of preceding events has been comparatively less explored, even though early immigrants in the fossil records are evidence for waif dispersals. The cricetid rodents of the subfamily Sigmodontinae are a classic example of a species-rich South American radiation resulting from an early episode of North American invasion. Here, we provide a temporal and spatial framework to address key aspects of the historical biogeography and diversification of this diverse mammal group by using mitochondrial and nuclear DNA datasets coupled with methods of divergence time estimation, ancestral area reconstruction and comparative phylogenetics. Relaxed-clock time estimates indicate that divergence of the Sigmodontinae began in the middle-late Miocene (ca. 12-9 Ma). Dispersal-vicariance analyses point to the arrival of a single lineage of northern invaders with a widespread ancestral distribution and imply that the initial differentiation between Central and South America gave rise to the most basal groups within the subfamily. These two major clades diversified in the late Miocene followed by the radiation of main tribes until the early Pliocene. Within the Oryzomyalia, tribes diverged initially in eastern South America whereas multiple dispersals into the Andes promoted further diversification of the majority of modern genera. A comparatively uniform background tempo of diversification explains the species richness of sigmodontines across most nodes, except for two akodontine genera with recent increases in diversification rates. The bridging of the Central American seaway and episodes of low sea levels likely facilitated the invasion of South America long before the onset of the post-Isthmian phase of the GABI.

Cellulose-based materials have been extensively investigated due to their abundance, renewable nature, and low abrasiveness and density. Cellulose nanocrystals (CNCs) stand out as nanometric particles of increasing technological interest, and also due to their potential use as nano-reinforcements to polymer composites. Since the effect of ultrasonic treatment on the structure and properties of CNCs is not yet fully understood, in this study the effect of ultrasonic output and hydrolysis time on yield and morphological, structural, and thermal properties of nanocrystals from microcrystalline cellulose (MCC) was studied. CNCs were prepared by conventional hydrolysis and compared to sonochemical extraction using 64 vol% H2SO4 at 45 °C. Sonication power varied from 50, 70 and 90%, and for each value a kinetic study was performed as a function of hydrolysis time until a colloidal gel suspension was obtained. Results showed that it was possible to obtain CNCs from MCC with reduced extraction time, whose thermal stability, aspect ratio and crystallinity index are comparable to those obtained by conventional acid hydrolysis. The ultrasound power intensity was the most important parameter to increase CNC sonochemical extraction productivity. The optimal CNC yield occurred at predetermined hydrolysis time intervals for each set of variables of low-intensity ultrasound-assisted hydrolysis. The disaggregation of freshly produced CNCs from MCC particles occurred simultaneously to size reduction of previously produced CNCs and conversion of amorphous phase into sugars. Due to the non-selective nature of sonochemical hydrolysis, it was proposed that hydrolysis proceeds regardless of the size and crystallinity degree of cellulose particles dispersed in the acidic medium. Therefore, there was an optimal hydrolysis time as a function of CNC yield for each set of hydrolysis parameters, since prolonged extraction times leaded to deterioration of the morphological and structural properties of CNCs.

The dust generated during the sandblasting process of the sandblasted and acid-etched (SLA) method, commonly used to treat the surface of Ti dental implants, poses significant challenges in maintaining a clean manufacturing environment and ensuring safe working conditions. Nevertheless, surface modification remains crucial for improved performance of Ti dental implants. To address this problem and propose a clean and simple surface modification process to potentially replace SLA modification, this study aimed to characterize the surfaces of commercially pure Ti (cp-Ti) samples treated by acid etching and compare them with SLA-treated samples in terms of surface roughness (Rq), wettability (assessed through contact angle measurements), mineralized matrix deposition (evaluated through simulated body fluid [SBF] soaking), cell viability, cell differentiation (assessed based on alkaline phosphatase activity), and mineralization (assessed using MTT assay). Acid-etched surfaces exhibited nano- and micro-roughness and higher hydrophilicity than SLA surfaces, which is conducive to forming a highly bioactive TiO2 surface. Moreover, acid-etched samples exhibited earlier hydroxyapatite deposition after SBF soaking than SLA samples. Furthermore, the acid-etched surfaces were nontoxic and displayed significantly higher cell viability and differentiation after seven days than SLA surfaces. These findings suggest that acid etching is a viable alternative to the SLA method, likely offering superior surface bioactivity and biocompatibility.

Pseudotrimezia juncifolia (Klatt) Lovo & A. Gil (Iridaceae) is a popularly known species with primarily ornamental economic interest. It has traditional uses as purgative, in conditions related to the menstrual cycle, for blood purification, as wound healing, and as anti-inflammatory. The anti-inflammatory and antinociceptive activities of the decoction from its aerial stems, corms, and stamens are described here with dereplication studies on LC-MS/MS supported by the GNPS platform, where phenolic compounds were annotated and correlated with its biological activity. The decoction was evaluated in chemical (formalin and capsaicin) and thermal (hot plate) induced nociception or carrageenan-induced inflammation in mice. Decoction (at 10, 30, or 100 mg/kg doses) significantly reduced formalin- or capsaicin-induced nociception. All doses also demonstrated an antinociceptive effect in the hot plate model increasing the time the animal spent in responding to thermal signal. Naloxone partially reversed the antinociceptive effect. An anti-inflammatory effect was observed since a reduction in cell migration, protein extravasation interleukin-1, and tumor necrosis factor production induced by carrageenan in the subcutaneous air pouch was quantified. Metabolomic analyses showed a predominance of phenolic substances, mainly flavonoids and chlorogenic acids. The literature showed that these two groups have significant anti-inflammatory and analgesic activity, and chemical data corroborate the pharmacological results observed.

Myelination by oligodendrocytes in the central nervous system is influenced by neuronal activity, but the molecular mechanisms by which this occurs have remained unclear. Here we employed pharmacological, genetic, functional imaging and optogenetic-stimulation approaches in zebrafish to assess activity-regulated myelination in vivo. Pharmacological inhibition and activation of metabotropic glutamate receptor 5 (mGluR5) impaired and promoted myelin sheath elongation, respectively, during development, without otherwise affecting the oligodendrocyte lineage. Correspondingly, mGluR5 loss-of-function mutants exhibit impaired myelin growth, while oligodendrocyte-specific mGluR5 gain of function promoted sheath elongation. Functional imaging and optogenetic-stimulation studies revealed that mGluR5 mediates activity-driven high-amplitude Ca 2+ transients in myelin. Furthermore, we found that long-term stimulation of neuronal activity drives myelin sheath elongation in an mGluR5-dependent manner. Together these data identify mGluR5 as a mediator of the influence of neuronal activity on myelination by oligodendrocytes in vivo, opening up opportunities to assess the functional relevance of activity-regulated myelination. Employing pharmacology, genetics and all-optical approaches in zebrafish, Braaker et al. find that neuronal activity influences the growth of myelin sheaths along axons by signaling through metabotropic glutamate receptor 5 on oligodendrocytes.

Background/Objectives: In recent years, silver nanoparticles (AgNPs) have garnered significant attention due to their potent antimicrobial properties, which hold promise for various applications. However, concerns about their potential toxicity have also emerged, particularly regarding their impact on human and animal health. This study investigates the acute toxicological effects of AgNPs synthesized using a green route with an aqueous extract of a native Cerrado plant (AgNPs-Cb) in mice. Methods: The AgNPs-Cb were intravenously administered at a concentration of 64 µM, and the mice were euthanized after 24 h for the collection of blood and organ samples (liver, spleen, kidneys, and lungs) for hematological, biochemical, and histological analyses. Results: Hematological analysis, including complete blood count (CBC) and differential leukocyte count, showed no statistically significant alterations in the groups treated with AgNPs-Cb, Cb extract, and Ag+, compared with the control group (p < 0.05). Notably, only the Ag+ group exhibited a significant increase in red blood cell count and hematocrit levels, suggesting that the nanoformulation of silver might mitigate the hematological impact seen with free silver ions. Biochemical analyses of liver and kidney function markers also revealed no significant differences across the treatment groups. Conclusions: These findings indicate that AgNPs-Cb may offer a safer alternative for antimicrobial applications, reducing the risk of acute toxicity in mammals while maintaining efficacy against pathogens. Further studies are needed to explore the underlying mechanisms and long-term effects of AgNPs-Cb exposure.

Tropical forests are often located in dicult-to-access areas, which make high-quality forest structure information dicult and expensive to obtain by traditional field-based approaches. LiDAR (acronym for Light Detection And Ranging) data have been used throughout the world to produce time-ecient and wall-to-wall structural parameter estimates for monitoring in native and commercial forests. In this study, we compare products and aboveground biomass (AGB) estimations from LiDAR data acquired using an aircraft-borne system in 2015 and data collected by the unmanned aerial vehicle (UAV)-based GatorEye Unmanned Flying Laboratory in 2017 for ten forest inventory plots located in the Chico Mendes Extractive Reserve in Acre state, southwestern Brazilian Amazon. The LiDAR products were similar and comparable among the two platforms and sensors. Principal dierences between derived products resulted from the GatorEye system flying lower and slower and having increased returns per second than the aircraft, resulting in a much higher point density overall (11.3 1.8 vs. 381.2 58 pts/m2). Dierences in ground point density, however, were much smaller among the systems, due to the larger pulse area and increased number of returns per pulse of the aircraft system, with the GatorEye showing an approximately 50% higher ground point density (0.27 0.09 vs. 0.42 0.09). The LiDAR models produced by both sensors presented similar results for digital elevation models and estimated AGB. Our results validate the ability for UAV-borne LiDAR sensors to accurately quantify AGB in dense high-leaf-area tropical forests in the Amazon. We also highlight new possibilities using the dense point clouds of UAV-borne systems for analyses of detailed crown structure and leaf area density distribution of the forest interior.