937 research outputs found
Effect of the fungicide Prochloraz-Mn on the cell wall structure of Verticillium fungicola
The chemical structure of the cell wall of two isolates of Verticillium fungicola collected from diseased fruit bodies of the commercial mushroom Agaricus bisporus treated with the fungicide Prochloraz-Mn was analyzed. The isolates were obtained during different periods of time and grown in the absence and presence of the LD50 values of the fungicide for V. fungicola. In addition, another V. fungicola isolate collected previous to the routine utilization of Prochloraz-Mn but grown under the same conditions was also analyzed. The overall chemical composition of the cell wall from the three isolates showed detectable differences in their basic components, with a significant decrease in the protein content in fungicide-treated cells. This inhibitory effect was partially compensated by an increase in neutral and/or aminated carbohydrates and was accompanied by appreciable modifications of polysaccharide structure, as deduced after methylation analysis and gas-liquid chromatography- mass spectrometry (GLC-MS). Moreover, differences in hyphal morphology caused by the fungicide were observed by transmission electron microscopy (TEM)
Initial pH as a determining factor of glucose consumption and lactic and acetic acid production in oral streptococci
Lactic and acetic acid production was evaluated from six strains of oral streptococci, viz Streptococcus gordonii, Streptococcus mutans, Streptococcus oralis, Streptococcus salivarius, Streptococcus sanguis and Streptococcus sobrinus cultured in the presence of 1, 5, 10 mM glucose and without glucose, at initial pH values of 5, 5.5, 6 and 7. S. sobrinus and S. salivarius caused the greatest decreases in pH. At pH values of 5 and 5.5, lactic acid and acetic acid production in the species tested was discordant with residual glucose levels. Acid production from protein was especially great in S. mutans and S. salivarius
Seed Size and Its Relationship with Crop Establishment, Productivity and Nutritive Value in Genotypes of Maize for Silage
For a high dry matter (DM) yield of forage maize an adequate population of plants is required, which is related to germination, vigour, and seed size (Ellis, 1992). The objective of the present study was to investigate seed size and its relationship to establishment, productive and nutritional potential of silage maize, which has not before been reported in the literature
CITOTOXICIDAD EN CÉLULAS HELA DE EXTRACTOS DE TRES ESPECIES DE PLANTAS MEDICINALES DE HIDALGO, MÉXICO
Ethanolic extracts of three medicinal plants,Juniperus deppeana, Solanum rostratumand Bidens odorata, which are used in folk medicine in Hidalgo, Mexico, for thetreatment of wounds, ulcers, tumors andcancer, were tested in a HeLa cell line toevaluate their cytotoxic activity. The highestcytotoxicity was found in the extract of J.deppeana (IC50 = 4.63 μg/ml); hence, thisextract was separated via chromatographyon a silica gel plate, from which the mainfraction (Rf = 0.28) showed strong cytotoxic activity (IC50 = 0.79 μg/ml). Whereasthe extract of S. rostratum also exhibitedcytotoxicity (IC50 = 127.5 μg/ml), that ofB. odorata was inactive.Se evaluó la citotoxicidad en cultivos decélulas HeLa de los extractos etanólicosde tres especies de plantas, Juniperus deppeana, Solanum rostratum y Bidens odorata, que se utilizan tradicionalmente en dosregiones del estado de Hidalgo, México,para el tratamiento de heridas, úlceras, tumores y cáncer de matriz. La citotoxicidadmás elevada la presentó el extracto de J.deppeana (CI50 = 4.63 μg/ml), el cual fueseparado por cromatografía en placa de gelde sílice y la fracción principal (Rf = 0.28 )mostró actividad citotóxica (CI50 = 0.79 μg/ml). Aunque menor, el extracto de S. rostratum también presentó citotoxicidad (CI50= 127.5 μg/ml). B. odorata fue inactiva
Steady-State 3D Trapping and Manipulation of Microbubbles Using Thermocapillary
[EN] An experimental and theoretical study on the 3D trapping and manipulation of microbubbles by means low power laser-induced temperature gradients induced in ethanol by bulk light absorption (¿ 1550 nm) is presented. Two optical fibers were used: One for bubble generation (OFG) and the other for both trapping and manipulation
(OFT). Light from a Q-switched pulsed laser (¿ 532 nm and pulse width ¿p 5 ns) propagates in fiber OFG and gets absorbed at silver nanoparticles (AgNPs), previously photodeposited, at the distal end of a fiber optic core, generating the microbubbles. In the fiber OFT, light of low power CW laser was used to trap and manipulate the bubbles by thermocapillary induced by light bulk absorption in ethanol. The microbubble generated on OFG migrates toward the fiber OFT. The equilibrium between the buoyancy force FB, drag force FD and the Marangoni force (also known as thermocapillary force) FM gives rise to a 3D stably trapping and manipulation of the microbubble for the best time to our best knowledge.This work was supported by CONACyT through the grant number A1-S-28440.Muñoz-Pérez, FM.; Ortega-Mendoza, JG.; Padilla-Vivanco, A.; Toxqui-Quitl, C.; Sarabia-Alonso, J.; Ramos-García, R. (2020). Steady-State 3D Trapping and Manipulation of Microbubbles Using Thermocapillary. Frontiers in Physics. 8. https://doi.org/10.3389/fphy.2020.585590
Recommended from our members
2D-cadmium MOF and gismondine-like zinc coordination network based on the N-(2-tetrazolethyl)-4′-glycine linker
We have designed and synthesized two new metal-organic-frameworks (MOFs) using the novel N-(2-tetrazolethyl)-4′-glycine spacer (TeGly)2−. These materials exhibit intense photoluminescence.This work was supported by the MEC of Spain (Project CTQ2011-24478) and the Junta de Andalucía (FQM-1484). D. F.-J. thanks the Royal Society for a University Research Fellowship.This is the author accepted manuscript. The final version is available from the Royal Society of Chemistry via http://dx.doi.org/10.1039/C5NJ00011
First survey of Wolf-Rayet star populations over the full extension of nearby galaxies observed with CALIFA
The search of extragalactic regions with conspicuous presence of Wolf-Rayet
(WR) stars outside the Local Group is challenging task due to the difficulties
in detecting their faint spectral features. In this exploratory work, we
develop a methodology to perform an automated search of WR signatures through a
pixel-by-pixel analysis of integral field spectroscopy (IFS) data belonging to
the Calar Alto Legacy Integral Field Area survey, CALIFA. This technique
allowed us to build the first catalogue of Wolf-Rayet rich regions with
spatially-resolved information, allowing to study the properties of these
complexes in a 2D context. The detection technique is based on the
identification of the blue WR bump (around He II 4686 {\AA}, mainly associated
to nitrogen-rich WR stars, WN) and the red WR bump (around C IV 5808 {\AA} and
associated to carbon-rich WR stars, WC) using a pixel-by-pixel analysis. We
identified 44 WR-rich regions with blue bumps distributed in 25 galaxies of a
total of 558. The red WR bump was identified only in 5 of those regions. We
found that the majority of the galaxies hosting WR populations in our sample
are involved in some kind of interaction process. Half of the host galaxies
share some properties with gamma-ray burst (GRB) hosts where WR stars, as
potential candidates to being the progenitors of GRBs, are found. We also
compared the WR properties derived from the CALIFA data with stellar population
synthesis models, and confirm that simple star models are generally not able to
reproduce the observations. We conclude that other effects, such as the binary
star channel (which could extend the WR phase up to 10 Myr), fast rotation or
other physical processes that causes the loss of observed Lyman continuum
photons, are very likely affecting the derived WR properties, and hence should
be considered when modelling the evolution of massive stars.Comment: 33 pages, accepted for publication in A&
- …