146 research outputs found
Conectividad molecular. Su aplicación a algunas propiedades físico-químicas de un grupo de alcoholes
Se ha aplicado el método de Conectividad Molecular a un grupo de alcoholes, usando como propiedades a correlacionar: la refracción molar, la entalpia de formación y la temperatura de ebullición, y como índices topológicos los de Kier y Hall y los geométricos. Los resultados indican que en estudios de relación estructura-actividad, así como en los de predicción, los índices geométricos son adecuados para propiedades moleculares (Rrn, ∆Hf), mientras que los de Kier y Hall lo son para propiedades molares (Te).Molecular connectlvlty method has been used for studying sorne physico chemical properties, such as molar refraction, heat of formation and boiling point,
in a group of alcohols, using the Kier and Hall's and geometrical indices.
The results indicate that these are the better for molecular properties (i.e. molar
refraction and heat of formation), while Kier and Hall's were for molar properties
(i.e. boiling temperature)
Productive evaluations of Aberdeen Angus and Argentina Criollo beef in two feeding systems in the northeast of The Pampa. Argentina
The objective of the study is to evaluate the productivity of two winter pastures under a rotational grazing system with and without energetic concentrates in the diet; in order to evaluate the productive behavior in Aberdeen Angus and Argentine Criollo beef. Sixty steer, castrated males of the breed Aberdeen Angus, of 6-7 months of age and 175 kg, and Argentine Criollo, at 8-9 months of age and 199 kg. The steer study were divided into four groups of 15 steer each. The study was conducted for 13 months in the first five months they grazed on oat farming (Avena sativa); and the following seven months on cebadilla (Bromus uniloides) and Lucerne (Medicago sativa) sown grassland, and the final month on oat. As a supplement they received ground grain sorghum (33 percent of the diet). The weight increment during the 13 months of the study went from 294,23 kg; 239,20 kg; 214,00 kg and 203,19 kg; an average weight gain of 0,754 kg/d; 0,613 kg/d; 0,549 kg/d and 0,520 kg/ d; a production per hectare of 374 kg/ha; 304 kg/ ha; 272 kg/ha and 258 kg/ha; and a stock efficiency of 77 percent, 67 percent, 59 percent, and 61 percent in the groups ACS, ASS, CCS and CSS, respectively.El objetivo del estudio es evaluar la productividad de dos invernadas pastoriles, bajo un sistema de pastoreo rotativo con y sin complemento de concentrados energéticos en la dieta; así como evaluar el comportamiento productivo de terneros Aberdeen Angus (AA) y Criollo Argentino (CA). Se cuenta con 60 terneros, machos castrados, de las razas Aberdeen Angus, con 6-7 meses de edad y 175 kg de peso, y Criollo Argentino, 8-9 meses de edad y 199 kg de peso. Se forman cuatro lotes de 15 terneros (ASS= Aberdeen sin complemento, ACS= Aberdeen con complemento, CSS= Criollo sin complemento y CCS= Criollo con complemento). El ensayo se realiza durante 13 meses: en los 5 primeros pastan en un cultivo de avena (Avena sativa) los siete meses siguientes en una pradera de alfalfa (Medicago sativa) y de cebadilla (Bromus uniloides) y en el último mes en un cultivo de avena. Como suplemento reciben grano de sorgo molido (33 p.100 de la dieta). El incremento medio de peso de los terneros, en los 13 meses de ensayo, fue 294,23 kg; 239,20 kg; 214,00 kg y 203,19 kg; la ganancia media de peso de 0,754 kg/d; 0,613 kg/d; 0,549 kg/d y 0,520 kg/d; la producción por hectárea de 374 kg/ ha, 304 kg/ha, 272kg/ha y 258 kg/ha; y la eficiencia en los lotes ACS, ASS, CCS y CSS, fue del 77, 67, 59 y 61 p.100, respectivamente
Conectividad molecular. Su aplicación a algunas propiedades físico-químicas de un grupo de alcoholes
Molecular connectlvlty method has been used for studying sorne physicochemical properties, such as molar refraction, heat of formation and boiling point, in a group of alcohols, using the Kier and Hall's and geometrical indices. The results indicate that these are the better for molecular properties (i.e. molar refraction and heat of formation), while Kier and Hall's were for molar properties (i.e. boiling temperature).Se ha aplicado el método de Conectividad Molecular a un grupo de alcoholes, usando como propiedades a correlacionar: la refracción molar, la entalpia de formación y la temperatura de ebullición, y como índices topológicos los de Kier y Hall y los geométricos. Los resultados indican que en estudios de relación estructura-actividad, así como en los de predicción, los índices geométricos son adecuados para propiedades moleculares (Rrn, ∆Hf), mientras que los de Kier y Hall lo son para propiedades molares (Te)
Nondecoupling effects from heavy Higgs bosons by matching 2HDM to HEFT amplitudes
In this work, we explore the low-energy effects induced from the integration of the heavy Higgs boson modes H, A, and H± within the two-Higgs-doublet model (2HDM) by assuming that the lightest Higgs boson h is the one observed experimentally at mh∼125 GeV. We work within the context of effective field theories, focusing on the Higgs effective field theory (HEFT), although some comparisons with the Standard Model effective field theory case are also discussed through this work. Our main focus is placed in the computation of the nondecoupling effects from the heavy Higgs bosons and the capture of such effects by means of the HEFT coefficients which are expressed in terms of the input parameters of the 2HDM. Our approach to solve this issue is by matching the amplitudes of the 2HDM and the HEFT for physical processes involving the light Higgs boson h in the external legs instead of the most frequently used matching procedure at the Lagrangian level. More concretely, we perform the matching at the amplitudes level for the following physical processes, including scattering and decays: h→WW∗→Wff′¯, h→ZZ∗→Zff¯, WW→hh, ZZ→hh, hh→hh, h→γγ, and h→γZ. One important point of this work is that the matching is required to happen at low energies compared to the heavy Higgs boson masses, and these are heavier than the other particle masses. The proper expansion for this heavy mass limit is also defined here, which provides the results for the nondecoupling effects presented in this work. We finally discuss the implications of the resulting effective coefficients and remark on the interesting correlations detected among themF. A., D. D., and M. J. H. acknowledge financial support from the grant IFT Centro de Excelencia Severo Ochoa CEX2020-001007-S funded by MCIN/AEI/10.13039/501100011033, from the Spanish “Agencia Estatal de Investigación” (AEI) and the EU “Fondo Europeo de Desarrollo Regional” (FEDER) through the project PID2019-108892RB-I00 funded by MCIN/AEI/10.13039/501100011033, and from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant agreement No. 860881-HIDDeN. F. A., D. D., and M. J. H. also acknowledge partial financial support by the Spanish Research Agency (Agencia Estatal de Investigación) through the Grant PID2022-137127NB-I00 funded by
MCIN/AEI/10.13039/501100011033/ FEDER, UE. The work of R. A. M. is also supported by CONICET and ANPCyT under projects PICT 2017-2751, PICT 2018- 03682 and PICT-2021-I-INVI-00374. The work of F. A. is also supported by the Grant PID2019-110058GB-C21 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe” and by the Spanish Ministry of Science and Innovation via an FPU Grant No. FPU18/0663
True prediction of lowest observed adverse effect levels
Summary A database of structurally heterogeneous chemical structures with their experimental values of Lowest Observed Adverse Effect Levels (LOAELs) was modeled using graph theoretical descriptors. Variable selection for multiple linear regression (MLR) and linear discriminant analysis (LDA) was accomplished by the Internal Test Set (ITS) method in order to achieve true predicted LOAEL values. The results obtained can be considered good if we take in count the structural diversity of the training set
Application of molecular topology to the prediction of antiparasitic activity against Giardia intestinalis and Trichomonas vaginalis of 2-Acylamino-nitro-1,3-thiazole products
Giardia intestinalis
y
Trichomonas vaginalis
destacan por su importancia clínica.
G. intestinalis
causa la giardiosis, una parasitosis de gran importancia epidemiológica y clínica por presentar una elevada prevalencia.
T. vaginalis
causa la tricomoniasis, la enfermedad de transmisión
sexual (ETS) no viral con mayor incidencia del mundo. Ambas parasitosis comparten el mismo tratamiento farmacológico: los nitroimidazoles. Se ha aplicado la topología molecular en
la búsqueda de derivados del 2-Acylamino-nitro-1,3-tiazol con actividad antiparasitaria frente
a
G. intestinalis
y
T. vaginalis
. Con el análisis lineal discriminante se obtuvo un modelo capaz
de clasificar correctamente el 92,85 % de los compuestos estudiados en ambos parásitos. Para
predecir la actividad antiparasitaria, se llevó a cabo un análisis de regresión multilineal capaz de
explicar el 83,2 % de la varianza en
G. intestinalis
, y el 89,4 % en
T. vaginalis
. Por último, se
llevó a cabo un cribado molecular para buscar nuevos compuestos potencialmente activos frente
a ambos parásitos.Giardia intestinalis
and
Trichomonas vaginalis
stand out for their clinical importance.
G. intestinalis
causes giardiasis, a parasitism of great epidemiological and clinical importance due to its
high prevalence.
T. vaginalis
causes trichomoniasis, the non-viral sexually transmitted disease
(STD) with the highest incidence in the world. Both parasitisms share the same pharmacological
treatment: nitroimidazoles. Molecular topology has been applied in searching for derivatives of
2-Acylamino-nitro-1,3-thiazole with antiparasitic activity against
G. intestinalis
and
T.
vaginalis. After using linear discriminant analyses, results show a model that could correctly classify the
activity of 92.85 % of the compounds studied in both parasites. To predict antiparasitic activity,
a multilinear regression analysis was carried out that could explain 83.2 % of the variance in
G.
intestinalis
, and 89.4 % in
T. vaginalis
. Finally, a molecular screening was carried out to look for
new potentially active compounds against both parasitesCiencias Experimentale
Application of molecular topology to the prediction of inhibition of Trypanosoma cruzi Hexokinase by bisphosphonates
Se ha desarrollado un modelo topológico-matemático para la búsqueda de nuevos derivados bisfosfonatos activos
frente a la hexokinasa de Trypanosoma cruzi. Utilizando el análisis lineal discriminante se ha seleccionado una función
con cuatro variables capaz de predecir adecuadamente la CI50 para cada compuesto de las series de entrenamiento
y test. El modelo propuesto se ha aplicado a una librería molecular y se han propuesto nuevas estructuras potencialmente activas frente a T. cruzi.A topological-mathematical model has been arranged to search for new derivatives of bisphosphonate compounds acting
as inhibitors against Trypanosoma cruzi hexokinase. By using linear discriminant analysis, a four-variable function was
achieved allowing an accurate prediction of the IC50 for each compound of the training and test series. After carrying
out a virtual screening based upon such a model, new structures potentially actives against T. cruzi are proposed.Este trabajo ha sido posible gracias al Fondo de Investigación Sanitaria, Ministerio de Sanidad, España (proyecto SAF2005-PIO52128) y al Máster Internacional en Enfermedades Parasitarias Tropicales, Universidad de Valencia
Aplicación de la topología molecular en la predicción de la inhibición de Trypanosoma cruzi Hexokinasa y un grupo de derivados bifosfonatos
A topological-mathematical model has been arranged to search for new derivatives of bisphosphonate compounds actingas inhibitors against Trypanosoma cruzi hexokinase. By using linear discriminant analysis, a four-variable function wasachieved allowing an accurate prediction of the IC50 for each compound of the training and test series. After carryingout a virtual screening based upon such a model, new structures potentially actives against T. cruzi are proposedSe ha desarrollado un modelo topológico-matemático para la búsqueda de nuevos derivados bisfosfonatos activosfrente a la hexokinasa de Trypanosoma cruzi. Utilizando el análisis lineal discriminante se ha seleccionado una funcióncon cuatro variables capaz de predecir adecuadamente la CI50 para cada compuesto de las series de entrenamientoy test. El modelo propuesto se ha aplicado a una librería molecular y se han propuesto nuevas estructuraspotencialmente activas frente a T. cruzi
Application of molecular topology to the prediction of antimalarial activity of 4-anilinoquinoline analogues
La malaria es una enfermedad parasitaria causada por protozoos del género
Plasmodium
y transmitida por vectores del género
Anopheles
. En 2019 esta enfermedad se cobró la vida de más de
400.000 personas, de las cuales un 94 % se concentraban en la región de África. Uno de los principales problemas en el control de la malaria es la aparición de resistencias frente a los diferentes
fármacos que existen, es por ello que es necesario el desarrollo de alternativas antimaláricas eficaces. En este estudio se ha aplicado la topología molecular a una serie de compuestos análogos
de la 4-anilinoquinolina con actividad inhibitoria de la proliferación de 3 cepas de
Plasmodium
falciparum, una sensible a la cloroquina (D6) y dos resistentes (W2 y C235); para así desarrollar
un modelo de relación cuantitativa estructura-actividad QSAR que permita predecir la actividad
de los compuestos frente a cada una de ellas. Utilizando el análisis lineal discriminante se seleccionaron tres funciones que clasificaron correctamente el 87
% de los compuestos analizados en
la cepa D6, en la W2 y en la C235, respectivamente. Para la validación del modelo se empleó
un test interno del tipo
leave some out
para cada una de las funciones. Por último, se aplicó el
modelo en la búsqueda de nuevos compuestos antimaláricos potencialmente activos frente a las
tres cepas.Malaria is a parasitic disease caused by the
Plasmodium
protozoa and transmitted by vector of
the genus
Anopheles
. In 2019, this disease claimed the lives of more than 400.000 people, of
which 94
% are concentrated in the African region. One of the main problems with malaria control is parasite resistance to the different drugs that exist, which is why it is necessary to develop
effective antimalarial alternatives. In this study, molecular topology was applied to 4-anilinoquinoline analogs with proliferation inhibitory activity of 3
Plasmodium falciparum
strains, one chloroquine sensitive (D6) and two chloroquine resistant (W2 and C235); in order to develop a
quantitative structure-activity (QSAR) model to predict the activity of the compounds against
each of them. Using linear discriminant analysis, three functions were selected that correctly
classified 87
% of the compounds analyzed in strain D6, W2 and C235, respectively. The
leave
some out
test was carried out to validate this model. Finally, the model was applied to search for
new antimalarial compounds potentially active against all three strains.Ciencias Experimentale
Application of molecular topology to the prediction of the repellent activity of a group of carboxyamides against Aedes aegypti
El mosquito Aedes aegypti presenta características biológicas que lo convierten en un vector importante en el ciclo de transmisión de diferentes patógenos, en especial arbovirus. Durante la última década, la carga de dengue y otras enfermedades tales como la fiebre del zika o fiebre chikungunya se han incrementado. La expansión de dengue ocasionada por este vector, principalmente en América, representa actualmente uno de los problemas más grandes de salud pública, siendo endémico en más de 30 países. Frente a la falta de tratamientos específicos para tratar las infecciones transmitidas por este mosquito, los esfuerzos por hacerle frente se han focalizado en el control vectorial, aplicando diversas estrategias de combate, entre las que se incluye la aplicación de insecticidas y larvicidas para conseguir su eliminación, así como el uso de repelentes como estrategia de protección individual. La búsqueda de nuevos repelentes puede realizarse mediante diferentes herramientas, donde se incluye la topología molecular. En este contexto, computacionalmente a través de un modelo topológico-matemático, evaluamos la potencial actividad repelente de una serie de carboxiamidas preseleccionadas mediante el uso de análisis discriminante lineal y de regresión multilineal. Tras este cribado virtual basado en el modelo seleccionado, proponemos nuevas estructuras químicas con una actividad potencialmente activa como repelentes contra Aedes aegypti.Due to its biological characteristics, the mosquito Aedes aegypti is an important vector in the transmission cycle of various pathogens, especially of arboviruses. The burden of dengue and
other diseases such as the Zika virus infection or the chikungunya fever has increased over the
last decade. The spread of dengue caused by this vector, mainly in America, represents one of
the greatest public health problems, being endemic in more than 30 countries. Faced with the
lack of specific treatments to treat the infections caused by this mosquito, efforts have focused on
controlling the vector, applying various combat strategies, including the application of Due to its biological characteristics, the mosquito Aedes aegypti is an important vector in the
transmission cycle of various pathogens, especially of arboviruses. The burden of dengue and
other diseases such as the Zika virus infection or the chikungunya fever has increased over the
last decade. The spread of dengue caused by this vector, mainly in America, represents one of
the greatest public health problems, being endemic in more than 30 countries. Faced with the
lack of specific treatments to treat the infections caused by this mosquito, efforts have focused on
controlling the vector, applying various combat strategies, including the application of insecticides
and larvicides to directly eliminate the mosquito population, as well as the use of repellants,
as an individual protection strategy. The search for new repellants can be done using different
tools, including molecular topology. In this context, using a topological-mathematical model, we
evaluated the potential repellent activity of a series of preselected carboxyamides by using linear
discriminant and multilinear regression analysis. After carrying out a virtual screening based on
the selected model, new chemical structures with potential activity as repellants against Aedes
aegypti are proposed.Ciencias Experimentale
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