Saint Elmo’s fire and lightning are two known forms of naturally occurring atmospheric pressure plasmas. As a technology, nonthermal plasmas are induced from artificially created electromagnetic or ...electrostatic fields. Here we report the observation of arguably a unique case of a naturally formed such plasma, created in air at room temperature without external electromagnetic action, by impinging a high-speed microjet of deionized water on a dielectric solid surface. We demonstrate that tribo-electrification from extreme and focused hydrodynamic shear is the driving mechanism for the generation of energetic free electrons. Air ionization results in a plasma that, unlike the general family, is topologically well defined in the form of a coherent toroidal structure. Possibly confined through its self-induced electromagnetic field, this plasmoid is shown to emit strong luminescence and discrete-frequency radio waves. Our experimental study suggests the discovery of a unique platform to support experimentation in low-temperature plasma science.
Erwinia psidii (Eps) is the causal agent of emerging diseases of eucalypt and guava; however, the mechanisms underlying its pathogenicity are not fully understood. Here, we predicted factors involved ...in the ability of Eps to cause disease on its host plants. For that, the genomes of four Eps strains exhibiting different virulence on eucalypt were sequenced, and hrp/hrc genes coding for the type III secretion system (T3SS), effectors injected into the plant cell cytoplasm through the T3SS (T3SEs) and their plant subcellular localizations, as well as proteins deployed to the host apoplast, were predicted. It was found that Eps possesses a complete hrp/hrc gene cluster based on comparison with Erwinia amylovora. A total of 18 T3SEs were predicted, 11 of which were shared among all strains, none were exclusive to any strain and seven were absent in at least one strain. No sequence variation among strains was found for five T3SE candidates whereas extensive variation was found for six, suggesting the latter may be determinants of virulence differences. The T3SE candidates are predicted to target the plant cell nucleus, cytoplasm, mitochondrion, chloroplast and peroxisome. The predicted apoplastic effector repertoire common to all four strains was over‐represented in proteins of unknown functions or predicted to possess enzymatic activities, among which the most abundant were oxidoreductases and peptidases. Proteins with lytic transglycosylase activity were predicted in strain‐specific apoplastic effector repertoires. These results provide an important framework for future research aimed at uncovering the factors underlying Eps pathogenicity.
Genome sequencing and bioinformatic analysis identified 18 type III and diverse apoplastic effectors with predicted unknown or enzymatic activities putatively associated with the ability of Erwinia psidii to infect its host plants.
This study aimed to identify the chemical composition of the
aqueous leaf and root extracts (EALST and EARST) and to evaluate their effect, comparatively, against opportunistic pathogenic fungi. ...Ultra-Performance Liquid Chromatography Coupled to a Quadrupole/Time of Flight System (UPLC-MS-ESI-QTOF) was employed for chemical analysis.
and
standard strains and clinical isolates were used (CA INCQS 40006, CT INCQS 40042, CA URM 5974, and CT URM 4262). The 50% Inhibitory Concentration for the fungal population (IC
) was determined for both the intrinsic action of the extracts and the extract/fluconazole (FCZ) associations. The determination of the Minimum Fungicidal Concentration (MFC) and the verification of effects over fungal morphological transitions were performed by subculture in Petri dishes and humid chambers, respectively, both based on micro-dilution. UPLC-MS-ESI-QTOF analysis revealed the presence of phenolic and flavonoid compounds. The association of the extracts with fluconazole, resulted in IC
values from 2.62 µg/mL to 308.96 µg/mL. The MFC of the extracts was ≥16,384 µg/mL for all tested strains, while fluconazole obtained an MFC of 8192 µg/mL against
strains. A reduction in MFC against CA URM 5974 (EALST: 2048 µg/mL and EARST: 1024 µg/mL) occurred in the extract/fluconazole association.
A scaled-model of a horizontal axis tidal current turbine (HATCT) is tested in the CNR-INM Circulating Water Channel. The experiments are designed to establish in the first place the performances of ...the turbine at different working settings. The second goal is to investigate the hydrodynamics generated by the turbine in the near wake using the Particle Image Velocimetry (PIV) technique. For this purpose, velocity measurements are performed in a longitudinal plane and phase-locked to the rotor angle in order to resolve the wake structure at different working regimes. The analysis of the axial and radial velocity fields reveals the flow features of the slipstream, as well as its expansion and dependence on the turbine operating parameters. Analysis of the non-diagonal terms of the Reynolds stress tensor provides insight into the onset of tip vortex pairing and of vortex instabilities. Furthermore the separate contributions of transport, production and dissipation to the turbulent kinetic energy in the wake field are discussed in detail. The vortex unsteadiness is captured and correlated with the evolution of the kinetic energy transport and production terms. Understanding these phenomenologies is an important step to develop computational tools able to estimate the radiated noise or the potential impact of turbulence on performances of further rotors placed in the wake, as in an array of tidal turbines.
•Topology of rotor wake is revealed via in-phase Particle Image Velocimetry (PIV).•Slipstream expansion is largest at maximum power coefficient.•Production and transport of turbulent kinetic energy are dominant in tip vortices.•Dissipation and viscous effects are negligible in the near wake.•Vorticity skewness is a probe into the spatial fluctuations of the tip vortex.
Abstract
Particle Image Velocimetry is employed to investigate the turbulence modulation induced by dispersed elongated, rod-like particles in a turbulent channel flow. Particles with two different ...aspect ratios AR=40,80 are tested, at a volume fraction of 10
-5
. Carrier flow velocimetry data and distribution and orientation data of dispersed particles are obtained by an ad-hoc single-camera phase-discrimination technique. Carrier flow data shows that in the near-wall region turbulence modulation by particle occurrs as well as a decrease of average streamwise velocity. Analysis of conditional probability density function of particles location reveals that particles locations statistically match flow regions with instantaneous low vorticity and high streamwise velocity, in particular in the near-wall region.
Due to the increase in fungal resistance to existing drugs, a need exists to search for new antifungals. This study aimed to evaluate the antifungal activity of α, β, and δ-damascone and inclusion ...complexes with β-cyclodextrin against different Candida spp. The inclusion complex of β-damascone was prepared by the co-evaporation method using three molar proportions (1:1; 2:1; 3:1 (βDA-βCD)) and analyzed using Fourier transform infrared spectroscopy (FTIR). Standard
Candida albicans
(CA INCQS 40,006),
Candida krusei
(CK INCQS 40,095), and
Candida tropicalis
(CT INCQS 40,042) strains were used to evaluate antifungal activity. The substances were tested individually or in association with fluconazole (FCZ). The IC
50
and cell viability curve constructions were performed using the microdilution method. The minimum fungicidal concentration (MFC) was determined by the subculture method in a solid medium. The α, β, and δ-DA isolated or in combination with fluconazole (FCZ) showed significant antifungal activity. β-damascone showed effective complexation in the three molar proportions assayed; however, none of the inclusion complexes was demonstrated clinically significant effects against the fungal tested. Then, all compounds have shown promising antifungal activities; however, in vivo assays are necessary to have therapeutical application in the future.
We have investigated Amblyomin-X-treated horse melanomas to better understand its mode of action through transcriptome analysis and the in vivo model. Amblyomin-X is a Kunitz-type homologous protein ...that selectively leads to the death of tumor cells via ER stress and apoptosis, currently under investigation as a new drug candidate for cancer treatment. Melanomas are immunogenic tumors, and a better understanding of the immune responses is warranted. Equine melanomas are spontaneous and not so aggressive as human melanomas are, as this study shows that the in vivo treatment of encapsulated horse melanoma tumors led to a significant reduction in the tumor size or even the complete disappearance of the tumor mass through intratumoral injections of Amblyomin-X. Transcriptome analysis identified ER- and mitochondria-stress, modulation of the innate immune system, apoptosis, and possibly immunogenic cell death activation. Interactome analysis showed that Amblyomin-X potentially interacts with key elements found in transcriptomics. Taken together, Amblyomin-X modulated the tumor immune microenvironment in different ways, at least contributing to induce tumor cell death.
A turbulent channel flow laden with elongated, fiber-like particles is investigated experimentally by optical techniques. The flow-particle inter-coupling is analyzed in the case of particles with an ...aspect ratio of 40 and 80, at two volume fractions, 10−5 and 10−4. An image processing technique is presented, which is employed to simultaneously obtain carrier flow velocimetry data and distribution and orientation data of dispersed particles. Turbulence enhancement is reported in the near-wall region, with a higher level of increase associated with higher aspect ratio particles. Comparison to fiber data suggests that this mechanism of turbulence modulation stems from a particles orientational behavior. The preferential particle distribution is reported to be dependent on the aspect ratio in the region close to the wall. The probability density function of the fibers’ orientation angle appears to be independent of the particle aspect ratio once it is conditioned to the fibers’ characteristic size.
Display omitted
•Cnidoscolus spp. is a novel plant source of medicinal purposes.•The main content of bioactive compounds were observed in the extracts from the whole plant.•Cnidoscolus spp. as ...pivotal sources of separation and identification of bioactive molecules with biotechnological applications
The application of medicinal plants are the most important biotechnological alternative in the treatment of numerous diseases, especially in developing countries, such as Brazil. Among them, we specified some specimens of the genus Cnidoscolus used as phytotherapies, with healing properties, analgesic, anti-inflammatory, antibiotic and diuretic, anticancer, among others. Such effects are possibly associated with the presence of terpenoids, alkaloids, coumarins, flavonoids phenolic compounds, among others. Thus, the objective of this work was to evaluate in the literature the studies on the phytochemical, ethnopharmacological and biotechnological applications of this genus, from 1998 to 2017. Among the sixty-one studies reported in this review, ten species are popularly utilized to pharmacological and/or biotechnological applications. Cnidoscolus aconitifolius and Cnidoscolus chayamansa are the most cited species, which were also supported by either animal or cellular investigations indicating some beneficial pharmacological actions like antioxidant, anti-inflammatory and potential cytotoxic activity. The plant parts of this genus under study are important as sources for the isolation and identification of bioactive molecules with biotechnological applications, among the many diseases treated with this phytotherapy. Given these verdicts, ethnopharmacological approaches are significant systematic tools in the determination of plant species that exhibit medicinal and nutritional purposes. The results presented here should further stimulate the development of validation studies to ensure the safe and effective use of these plant species.
The application of phytases for animal feed in developing countries is limited due to the high cost of these enzymes, determined by the importation fees and the expensive substrates used for their ...production. In this work, we have used agroindustrial byproducts for the production of extracts containing phytases, which were accessed for their stability focusing on the conditions found in the gastrointestinal tract of pigs. The fungus Acremonim zeae presented higher phytase production in medium containing cornmeal, while the yeast Kluyveromyces marxianus produced 10-fold more phytase when cultivated on rice bran. Process optimization increased the difference in productivity to more than 300 fold. The phytase from A. zeae was thermostable, with higher activity at neutral pH and 50 °C, but was inhibited at pH 2.5 and by various ions. The phytase activity in the K. marxianus extract was stable at a wide range of conditions, which indicates the presence of at least two enzymes. As far as we know, this manuscript describes for the first time the phytase production and the characteristics of the extracts produced by both these microbial species. These enzymes could be produced at low cost and have potential to replace enzymes currently imported for this purpose.
PDF
