269 research outputs found
Micrografía cuantitativa y perfiles de HPLC y FTIR de Melissa officinalis y Nepeta cataria (Lamiaceae) de Argentina
Melissa officinalis L., so called "Melissa" or "Toronjil", is a perennial aromatic herb, whose leaves are used in traditional medicine as a carminative, digestive and sedative, both in simple as in mixtures. Meanwhile, Nepeta cataria L., commonly called "Cat mint" or "Toronjil", with some similar properties, often replacing M. officinalis in the market, although their chemical composition is not completely matched, and contains an iridoid potentially toxic (nepetalactone). It is therefore necessary to establish diacritic parameters to differentiate these species, both at crude drug level, mixtures and extracts. Samples from various sources in Argentina were studied and documental specimens are preserved in the Herbarium UNSL. Anatomical sections were analyzed, and quantitative micrographic parameters were obtained, together with HPLC and FTIR spectra from methanolic and aqueous lyophilized extracts. Significant differences were detected in the prevailing smell foliage, morphology of leaves and inflorescences, trichomata type, palisade ratio, veinlet termination number, rosmarinic acid concentration (with distinctive HPLC profiles), and the CO/CH relationships obtained by FTIR from the extracts, that together allow adequate differentiation of both drugs, even when they were ground or powdered.Melissa officinalis L., llamada vulgarmente "melisa" o "toronjil", es una hierba perenne, aromática, cuyas hojas son empleadas en medicina popular como carminativo, digestivo y sedante, tanto en droga simple como en asociación. Por su parte Nepeta cataria L., llamada vulgarmente "menta de los gatos" y también "toronjil", con algunas propiedades similares, sustituye con frecuencia a M. officinalis en el mercado, aunque su composición química no es del todo coincidente y contiene un iridoide potencialmente tóxico (nepetalactona). Por ello es necesario establecer parámetros diacríticos para diferenciar ambas especies, a nivel de droga cruda, mezclas y extractos. Fueron estudiados especímenes de diversas procedencias en Argentina, y los ejemplares documentales son conservados en el Herbario UNSL. Se analizaron cortes anatómicos, se registraron los parámetros micrográficos cuantitativos y se obtuvieron espectros de HPLC y FTIR a partir de extractos metanólicos y acuosos liofilizados. Fueron detectadas diferencias significativas entre ambas especies en cuanto al aroma prevaleciente del follaje, la exomorfología de hojas e inflorescencias, los tipos tricomáticos, la relación de empalizada, el número de terminales de nerviación, la concentración de ácido rosmarínico (con perfiles HPLC distintivos), y las relaciones CO/CH obtenidas por FTIR a partir de los extractos, caracteres que en conjunto permiten una diferenciación adecuada de ambas drogas, aún cuando se presenten molidas o reducidas a polvo.Fil: Petenatti, Marta E.. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Gette, Maria de Los Angeles. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Camí, Gerardo Enrique. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Popovich, Mariana C.. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Marchevsky, Eduardo Jorge. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: del Vitto, Luis Angel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Petenatti, Elisa Margarita. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentin
Experimental Demonstration of Nanolaser with sub-A Threshold Current
We demonstrate a photonic crystal nanolaser exhibiting an ultra-low threshold
of 730 nA at telecom wavelengths. The laser can be directly modulated at 3 GHz
at an energy cost of 1 fJ/bit. This is the lowest threshold reported for any
laser operating at room temperature and facilitates low-energy on-chip links.Comment: 3 pages with 2 figure
Micrografía cuantitativa y perfiles de HPLC y FTIR de Melissa officinalis y Nepeta cataria (Lamiaceae) de Argentina
Melissa officinalis L., so called "Melissa" or "Toronjil", is a perennial aromatic herb, whose leaves are used in traditional medicine as a carminative, digestive and sedative, both in simple as in mixtures. Meanwhile, Nepeta cataria L., commonly called "Cat mint" or "Toronjil", with some similar properties, often replacing M. officinalis in the market, although their chemical composition is not completely matched, and contains an iridoid potentially toxic (nepetalactone). It is therefore necessary to establish diacritic parameters to differentiate these species, both at crude drug level, mixtures and extracts. Samples from various sources in Argentina were studied and documental specimens are preserved in the Herbarium UNSL. Anatomical sections were analyzed, and quantitative micrographic parameters were obtained, together with HPLC and FTIR spectra from methanolic and aqueous lyophilized extracts. Significant differences were detected in the prevailing smell foliage, morphology of leaves and inflorescences, trichomata type, palisade ratio, veinlet termination number, rosmarinic acid concentration (with distinctive HPLC profiles), and the CO/CH relationships obtained by FTIR from the extracts, that together allow adequate differentiation of both drugs, even when they were ground or powdered.Melissa officinalis L., llamada vulgarmente "melisa" o "toronjil", es una hierba perenne, aromática, cuyas hojas son empleadas en medicina popular como carminativo, digestivo y sedante, tanto en droga simple como en asociación. Por su parte Nepeta cataria L., llamada vulgarmente "menta de los gatos" y también "toronjil", con algunas propiedades similares, sustituye con frecuencia a M. officinalis
en el mercado, aunque su composición química no es del todo coincidente y contiene un iridoide potencialmente tóxico (nepetalactona). Por ello es necesario establecer parámetros diacríticos para diferenciar ambas especies, a nivel de droga cruda, mezclas y extractos. Fueron estudiados especímenes de diversas procedencias en
Argentina, y los ejemplares documentales son conservados en el Herbario UNSL.
Se analizaron cortes anatómicos, se registraron los parámetros micrográficos cuantitativos y se obtuvieron espectros de HPLC y FTIR a partir de extractos metanólicos y acuosos liofilizados. Fueron detectadas diferencias significativas
entre ambas especies en cuanto al aroma prevaleciente del follaje, la exomorfología de hojas e inflorescencias, los tipos tricomáticos, la relación de empalizada, el número de terminales de nerviación, la concentración de ácido rosmarínico (con perfiles HPLC distintivos), y las relaciones CO/CH obtenidas por FTIR a partir de los extractos, caracteres que en conjunto permiten una diferenciación adecuada de ambas drogas, aún cuando se presenten molidas o reducidas a polvo.Fil: Petenatti, Marta E..
Universidad Nacional de San LuisFil: Gette, María A..
Universidad Nacional de San LuisFil: Camí, Gerardo E..
Universidad Nacional de San LuisFil: Popovich, Mariana C..
Universidad Nacional de San LuisFil: Marchevsky, Eduardo J..
Universidad Nacional de San LuisFil: Del Vitto, Luis A..
Universidad Nacional de San LuisFil: Petenatti, Elisa M..
Universidad Nacional de San Lui
V-I characteristics in the vicinity of order-disorder transition in vortex matter
The shape of the V-I characteristics leading to a peak in the differential
resistance r_d=dV/dI in the vicinity of the order-disorder transition in NbSe2
is investigated. r_d is large when measured by dc current. However, for a small
Iac on a dc bias r_d decreases rapidly with frequency, even at a few Hz, and
displays a large out-of-phase signal. In contrast, the ac response increases
with frequency in the absence of dc bias. These surprisingly opposite phenomena
and the peak in r_d are shown to result from a dynamic coexistence of two
vortex matter phases rather than from the commonly assumed plastic depinning.Comment: 12 pages 4 figures. Accepted for publication in PRB rapi
Flow Induced Organization and Memory of a Vortex Lattice
We report on experiments probing the evolution of a vortex state in response
to a driving current in 2H-NbSe crystals. By following the vortex motion
with fast transport measurements we find that the current enables the system to
reorganize and access new configurations. During this process the system
exhibits a long-term memory: if the current is turned off the vortices freeze
in place remembering their prior motion. When the current is restored the
motion resumes where it stopped. The experiments provide evidence for a
dynamically driven structural change of the vortex lattice and a corresponding
dynamic phase diagram that contains a previously unknown regime where the
critical current can be either or by applying an
appropriate driving current.Comment: 5 pages, 4figure
Composición multielemental y valor nutricional de "dumosa" (Ilex dumosa), "yerba mate" (I. paraguariensis) y su mezcla comercial en diferentes formas de uso
The multielement composition and nutritional value of "dumosa" (Ilex dumosa) (ID),
"yerba mate" (I. paraguariensis) (IP) and their commercial 70:30 mixture (ID:IP, w/w)
in crude drug, brewed mate and tea-bag-like infusion were studied by ICP-OES. This
method allowed the detection of an unprecedented number of elements for these
species. The order was K>Ca>Mg>P>Mn>Al>Na>Si>Fe in crude drug. IP showed higher
concentration of minerals than ID, but most extractability in the latter largely offset its
shortcomings. Brewed mate had higher nutritional value than mate tea because their
higher solute/solvent ratio. A portion of brewed mate of both species exceeded the daily
recommended intake (DRI) of Mn, and providing Mg, Cu, Fe, Zn and K, too. The portions of
mate tea not contribute significantly to the DRI. Some essential trace elements and many
ultra-traces ones that exist in crude drug were not detected in aqueous extracts. Most of
the heavy metals were not leached into extracts, and in any case never exceeded international
safety limits. Therefore, the aqueous extracts of ID and IP and its mixture are
interesting from the nutritional point of view in minerales, and safe in terms of health.La composición multielemental y el valor nutricional de "dumosa" (Ilex dumosa) (ID),
"yerba mate" (I. paraguariensis) (IP) y su mezcla comercial 70:30 (ID:IP, p/p) fue estudiada
por ICP-OES en droga cruda y dos formas de consumo: "cebadura" y "mate cocido". Este
método permitió detectar un número sin precedentes de elementos en estas especies. En
droga cruda, el orden resultó K>Ca>Mg>P>Mn>Al>Na>Si>Fe. IP mostró mayor concentración
de minerales que ID, pero la mayor extractabilidad en esta última compensó
en gran medida sus deficiencias. La cebadura mostró mayor valor nutricional que la
infusión, a causa de su mayor relación soluto/disolvente. La porción de cebadura de
ambas especies superó la ingesta diaria recomendada (IDR) de Mn, aportando también
Mg, Cu, Fe, Zn y K. La porción de mate cocido no contribuyó significativamente a la IDR.
Algunos elementos traza esenciales y muchos ultra-trazas presentes en droga cruda no
fueron detectados en los extractos acuosos. La mayoría de los metales pesados no fueron
lixiviados hacia los extractos, y en todo caso nunca excedieron los límites de seguridad
internacionales. Por ello, los extractos acuosos de ID e IP y sus mezclas son interesantes
desde el punto de vista nutricional y son seguros en cuanto a la salud.Fil: Maiocchi, Marcos G..
Universidad Nacional del NordesteFil: Del Vitto, Luis A..
Universidad Nacional de San LuisFil: Petenatti, Marta E..
Universidad Nacional de San LuisFil: Avanza, María V..
Universidad Nacional del NordesteFil: Pellerano, Roberto G..
Universidad Nacional del NordesteFil: Petenatti, Elisa M..
Universidad Nacional de San LuisFil: Marchevsky, Eduardo J.
Evaluation of macro and microminerals in crude drugs and infusions of five herbs widely used as sedatives
It has been determined the concentration of fourteen micro and macrominerals (Al, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, P, Se, and Zn) in both crude drugs and infusions of Melissa officinalis L., Lamiaceae, Nepeta cataria L., Lamiaceae, Passiflora caerulea L., Passifloraceae, Tilia x moltkei Späth ex C.K. Schneid., Tiliaceae, and Valeriana officinalis L., Caprifoliaceae. These herbs are widely consumed by its sedative properties, either alone or in herb mixtures. All measurements were performed using an inductively coupled plasma optical emission spectrometer (ICP-OES). The products were obtained from regional markets, mainly in San Luis province (Argentina). The estimated daily intake was compared with current recommendations. All products and its infusions were included within the upper tolerable limits for minerals, in trace elements such as toxic elements present at low levels
Multielemental composition and nutritional value of "dumosa" (Ilex dumosa), "yerba mate" (I. paraguariensis) and their commercial mixture in different forms of use
La composición multielemental y el valor nutricional de "dumosa" (Ilex dumosa) (ID),"yerba mate" (I. paraguariensis) (IP) y su mezcla comercial 70:30 (ID:IP, p/p) fue estudiadapor ICP-OES en droga cruda y dos formas de consumo: "cebadura" y "mate cocido". Estemétodo permitió detectar un número sin precedentes de elementos en estas especies. Endroga cruda, el orden resultó K;Ca;Mg;P;Mn;Al;Na;Si;Fe. IP mostró mayor concentraciónde minerales que ID, pero la mayor extractabilidad en esta última compensóen gran medida sus deficiencias. La cebadura mostró mayor valor nutricional que lainfusión, a causa de su mayor relación soluto/disolvente. La porción de cebadura deambas especies superó la ingesta diaria recomendada (IDR) de Mn, aportando tambiénMg, Cu, Fe, Zn y K. La porción de mate cocido no contribuyó significativamente a la IDR. Algunos elementos traza esenciales y muchos ultra-trazas presentes en droga cruda nofueron detectados en los extractos acuosos. La mayoría de los metales pesados no fueronlixiviados hacia los extractos, y en todo caso nunca excedieron los límites de seguridadinternacionales. Por ello, los extractos acuosos de ID e IP y sus mezclas son interesantesdesde el punto de vista nutricional y son seguros en cuanto a la saludThe multielement composition and nutritional value of "dumosa" (Ilex dumosa) (ID),"yerba mate" (I. paraguariensis) (IP) and their commercial 70:30 mixture (ID:IP, w/w) in crude drug, brewed mate and tea-bag-like infusion were studied by ICP-OES. Thismethod allowed the detection of an unprecedented number of elements for thesespecies. The order was K;Ca;Mg;P;Mn;Al;Na;Si;Fe in crude drug. IP showed higherconcentration of minerals than ID, but most extractability in the latter largely offset itsshortcomings. Brewed mate had higher nutritional value than mate tea because theirhigher solute/solvent ratio. A portion of brewed mate of both species exceeded the dailyrecommended intake (DRI) of Mn, and providing Mg, Cu, Fe, Zn and K, too. The portions ofmate tea not contribute significantly to the DRI. Some essential trace elements and manyultra-traces ones that exist in crude drug were not detected in aqueous extracts. Most ofthe heavy metals were not leached into extracts, and in any case never exceeded internationalsafety limits. Therefore, the aqueous extracts of ID and IP and its mixture areinteresting from the nutritional point of view in minerales, and safe in terms of health
Zinc recovery during refractory ore biooxidation by an indigenous consortium
Two enrichment cultures (one iron oxidizing and one sulfur oxidizing) obtained from an acid mine drainage were physiological and molecular characterized; the first of them showed 99% 16S rRNA gene sequence similarity with Leptospirillum ferrooxidans, while the sulfur oxidizing species was highly related to Acidithiobacillus ferrooxidans and Acidithiobacillus ferrivorans sequences although, unlike them, the species in the enrichment culture does not seem to be able to oxidize iron. The consortium constituted by both enrichment cultures achieved a successful biooxidation of Hualilan ore allowing the increase of gold recovery up to 96.4 % in the best culture condition (low pulp density in 1K medium). At the same time, this condition showed an effective zinc bioleaching (up to 86 %) although the recovery was much higher in cultures with initially supplemented iron; kinetics studies suggested that bioleaching rate in 1K medium at low pulp densities is controlled by diffusion through a layer mainly constituted by jarosite (rather than sulfur) which was detected in X-ray diffraction diagrams. The recovery of zinc as subproduct of the pretreatment to optimize gold recovery would also allow decrease the metallic charge of the leachates from the biooxidation tanks which is an environmental advantage.Centro de Investigación y Desarrollo en Fermentaciones Industriale
Dynamical Phases of Driven Vortices Interacting with Periodic Pinning
The finite temperature dynamical phases of vortices in films driven by a
uniform force and interacting with the periodic pinning potential of a square
lattice of columnar defects are investigated by Langevin dynamics simulations
of a London model. Vortices driven along the [0,1] direction and at densities
for which there are more vortices than columnar defects () are
considered. At low temperatures, two new dynamical phases, elastic flow and
plastic flow, and a sharp transition between them are identified and
characterized according to the behavior of the vortex spatial order, velocity
distribution and frequency-dependent velocity correlationComment: 4 pages with 4 figures. To be published in Phys. Rev. B Rapid
Communication
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