The traditional learning style theory is being used in the development of e-learning materials pr... more The traditional learning style theory is being used in the development of e-learning materials progressively. Usually the process of working with learning styles begins with the development of tests or questionnaires that are focus on determining the preferences of students to learn, and then prepare the material according to them. But once the content is implemented there is no tool to measure or estimate if it complies with the desired learning styles. We use a different approach and in this paper we perform the evaluation of existing pedagogical materials in order to determine the dominant learning style theory if there is any. Then the experimental result shows the classification of all the contents.
Recent research on the learning process has shown that students tend to learn in different ways a... more Recent research on the learning process has shown that students tend to learn in different ways and that they prefer to use different teaching resources as well. Many researchers agree on the fact that learning materials shouldn't just reflect of the teacher's style, but should be designed for all kinds of students and all kind of learning styles. Even though they agree on the importance of applying these learning styles to different learning systems, various problems still need to be solved, such as matching teaching contents with the student's learning style. In this paper, we describe the design of a personalized teaching method that is based on an adaptive taxonomy using Felder and Silverman's learning styles and which is combined with the selection of the appropriate teaching strategy and the appropriate electronic media. Students are able to learn and to efficiently improve their learning process with such method.
The probable antipyretic, antiinflammatory, analgesic and antioxidant properties of Kageneckia ob... more The probable antipyretic, antiinflammatory, analgesic and antioxidant properties of Kageneckia oblonga, Rosaceae, were investigated and the major compounds of its active extracts were isolated. The study comprised the acute toxicity of the extracts of global methanol, hexane, dichloromethane and methanol. The cytotoxicity of global methanol extract was studied in three tumoral cell lines. All the extracts exhibited the pharmacological activities under study. Methanol and dichloromethane were the most toxic extracts. From the global methanol extract, isolations were performed of prunasin, 23,24-dihydro-cucurbitacin F, and a new cucurbitacin, 3 -( -d-glucosyloxy)-16α,23α-epoxycucurbita-5,24-diene-11-one. The cytotoxicity of both cucurbitacins on human neutrophils at the assayed concentrations was not statistically significant. In-vitro assays showed that both cucurbitacins can be partly responsible for the analgesic, antipyretic, and anti-inflammatory activities.
In a previous work, we investigated the effects of a series of dimethoxy- and trimethoxychalcone ... more In a previous work, we investigated the effects of a series of dimethoxy- and trimethoxychalcone derivatives, with various patterns of fluorination, on nitric oxide production in lipopolysaccharide-stimulated murine RAW 264.7 cells. The present study was designed to determine if 2,4,6-trimethoxy-2'-trifluoromethylchalcone (ttCH) could modulate the production of nitric oxide (NO) and/or prostaglandins in vitro and in vivo. On the mouse macrophage cell line RAW 264.7, ttCH inhibited dose-dependently NO and prostaglandin E(2) production, with IC(50) in the micromolar range. This compound had no direct inhibitory effect on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 activities. NO reduction was the consequence of inhibition of the expression of iNOS. This compound also exhibited in vivo an inhibitory behaviour on nitrite and prostaglandin E(2) levels. We have assessed the effect of ttCH in the treatment of acute and chronic inflammatory processes such as the mouse carrageenan paw oedema and the rat adjuvant-induced arthritis. The present study demonstrated that ttCH exerts acute and chronic anti-inflammatory effects that may be related with the inhibition of iNOS expression.
Naunyn-schmiedebergs Archives of Pharmacology, 2003
We have previously investigated the effects of a series of dimethoxy- and trimethoxychalcone deri... more We have previously investigated the effects of a series of dimethoxy- and trimethoxychalcone derivatives, with various patterns of fluorination, on nitric oxide production in LPS-stimulated murine RAW 264.7. The present study was designed to determine if 3,4,5-trimethoxy-4'-fluorochalcone (CH 17) could modulate the production of NO and/or prostaglandins in vivo. On the mouse macrophage cell line RAW 264.7 CH 17 inhibited dose-dependently NO production, with an IC50 value in the nanomolar range, and reduced PGE2 levels by a 58% at 10 μM. This compound had no direct inhibitory effect on iNOS and COX-2 activities. NO reduction was the consequence of inhibition of the expression of iNOS. In vitro experiments indicated that CH 17 is an inhibitor of the nuclear factor-κB (NF-κB) pathway of cellular activation in macrophages. This compound exhibited in vivo an inhibitory behaviour correlated with its in vitro results on nitrite and PGE2 accumulation. In the rat adjuvant-induced arthritis, oral administration of CH 17 (25 mg/kg) on days 17–24 after adjuvant injection, significantly inhibited paw oedema, protected from weight loss and reduced the levels of inflammatory mediators (nitrites and PGE2) in paw homogenates, without affecting PGE2 levels in stomach homogenates. The profile and potency of this compound, a selective inhibitor of iNOS expression that interferes with NF-κB activation, may have relevance for the inhibition of the inflammatory response, representing a new approach to the modulation of different inflammatory pathologies.
A series of nine dimethylamino-chalcone derivatives (1,3-diaryl-propenones) was synthesized and s... more A series of nine dimethylamino-chalcone derivatives (1,3-diaryl-propenones) was synthesized and screened as potential inhibitors of NO and PGE2 production in the RAW 264.7 macrophage cell line. 4-Dimethylamino-2′,5′-dimethoxychalcone (6) was found to be the most potent and dual inhibitor (IC50s in the submicromolar range) of NO and PGE2 production. 2′,6′-Dimethoxylation appeared to be an effective requirement for selective and potent inhibition of nitric oxide synthase induction as it was confirmed by Western blot analysis. Chalcone (6) at 25 mg kg−1 by oral route, inhibited significantly the formation of oedema in the carrageenan-induced model of inflammation in mice.
3-(3-Pyridyl)-2-hydroxy-2-phosphonopropanoic acid (3-PEHPC, 1) is a phosphonocarboxylate (PC) ana... more 3-(3-Pyridyl)-2-hydroxy-2-phosphonopropanoic acid (3-PEHPC, 1) is a phosphonocarboxylate (PC) analogue of 2-(3-pyridyl)-1-hydroxyethylidenebis(phosphonic acid) (risedronic acid, 2), an osteoporosis drug that decreases bone resorption by inhibiting farnesyl pyrophosphate synthase (FPPS) in osteoclasts, preventing protein prenylation. 1 has lower bone affinity than 2 and weakly inhibits Rab geranylgeranyl transferase (RGGT), selectively preventing prenylation of Rab GTPases. We report here the synthesis and biological studies of 2-hydroxy-3-imidazo[1,2-a]pyridin-3-yl-2-phosphonopropionic acid (3-IPEHPC, 3), the PC analogue of minodronic acid 4. Like 1, 3 selectively inhibited Rab11 vs. Rap 1A prenylation in J774 cells, and decreased cell viability, but was 33-60Â more active in these assays. After resolving 3 by chiral HPLC (>98% ee), we found that (þ)-3-E1 was much more potent than (-)-3-E2 in an isolated RGGT inhibition assay, ∼17Â more potent (LED 3 μM) than (-)-3-E2 in inhibiting Rab prenylation in J774 cells and >26Â more active in the cell viability assay. The enantiomers of 1 exhibited a 4-fold or smaller potency difference in the RGGT and prenylation inhibition assays.
Esta ficha de estudio intenta facilitar el acceso a la lectura del ensayo "Imaginarios Sociales y... more Esta ficha de estudio intenta facilitar el acceso a la lectura del ensayo "Imaginarios Sociales y Sustentabilidad" de Enrique Leff. Este ensayo fue seleccionado como material de lectura para IESCA por haber sido considerado relevante para introducir la idea de imaginario social 3 en el estudio de las relaciones entre sociedad-cultura-naturaleza.
En el agua el O esta unido mediante enlaces covalentes simples a 2 átomos de H. Como el O es mas ... more En el agua el O esta unido mediante enlaces covalentes simples a 2 átomos de H. Como el O es mas electronegativo que el H, el par de e-compartido está desplazado hacia el núcleo de O. Se crea una nube o densidad (-) alrededor del O y una nube o densidad (+) alrededor del H. Se forma un polo positivo y uno negativo: dipolo.
FICHA DE CÁTEDRA: APORTES DEL PSICOANALISIS A LA REFLEXION SOBRE LA CULTURA: "EL MALESTAR EN LA C... more FICHA DE CÁTEDRA: APORTES DEL PSICOANALISIS A LA REFLEXION SOBRE LA CULTURA: "EL MALESTAR EN LA CULTURA" Sigmund Freud
The traditional learning style theory is being used in the development of e-learning materials pr... more The traditional learning style theory is being used in the development of e-learning materials progressively. Usually the process of working with learning styles begins with the development of tests or questionnaires that are focus on determining the preferences of students to learn, and then prepare the material according to them. But once the content is implemented there is no tool to measure or estimate if it complies with the desired learning styles. We use a different approach and in this paper we perform the evaluation of existing pedagogical materials in order to determine the dominant learning style theory if there is any. Then the experimental result shows the classification of all the contents.
Recent research on the learning process has shown that students tend to learn in different ways a... more Recent research on the learning process has shown that students tend to learn in different ways and that they prefer to use different teaching resources as well. Many researchers agree on the fact that learning materials shouldn't just reflect of the teacher's style, but should be designed for all kinds of students and all kind of learning styles. Even though they agree on the importance of applying these learning styles to different learning systems, various problems still need to be solved, such as matching teaching contents with the student's learning style. In this paper, we describe the design of a personalized teaching method that is based on an adaptive taxonomy using Felder and Silverman's learning styles and which is combined with the selection of the appropriate teaching strategy and the appropriate electronic media. Students are able to learn and to efficiently improve their learning process with such method.
The probable antipyretic, antiinflammatory, analgesic and antioxidant properties of Kageneckia ob... more The probable antipyretic, antiinflammatory, analgesic and antioxidant properties of Kageneckia oblonga, Rosaceae, were investigated and the major compounds of its active extracts were isolated. The study comprised the acute toxicity of the extracts of global methanol, hexane, dichloromethane and methanol. The cytotoxicity of global methanol extract was studied in three tumoral cell lines. All the extracts exhibited the pharmacological activities under study. Methanol and dichloromethane were the most toxic extracts. From the global methanol extract, isolations were performed of prunasin, 23,24-dihydro-cucurbitacin F, and a new cucurbitacin, 3 -( -d-glucosyloxy)-16α,23α-epoxycucurbita-5,24-diene-11-one. The cytotoxicity of both cucurbitacins on human neutrophils at the assayed concentrations was not statistically significant. In-vitro assays showed that both cucurbitacins can be partly responsible for the analgesic, antipyretic, and anti-inflammatory activities.
In a previous work, we investigated the effects of a series of dimethoxy- and trimethoxychalcone ... more In a previous work, we investigated the effects of a series of dimethoxy- and trimethoxychalcone derivatives, with various patterns of fluorination, on nitric oxide production in lipopolysaccharide-stimulated murine RAW 264.7 cells. The present study was designed to determine if 2,4,6-trimethoxy-2'-trifluoromethylchalcone (ttCH) could modulate the production of nitric oxide (NO) and/or prostaglandins in vitro and in vivo. On the mouse macrophage cell line RAW 264.7, ttCH inhibited dose-dependently NO and prostaglandin E(2) production, with IC(50) in the micromolar range. This compound had no direct inhibitory effect on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 activities. NO reduction was the consequence of inhibition of the expression of iNOS. This compound also exhibited in vivo an inhibitory behaviour on nitrite and prostaglandin E(2) levels. We have assessed the effect of ttCH in the treatment of acute and chronic inflammatory processes such as the mouse carrageenan paw oedema and the rat adjuvant-induced arthritis. The present study demonstrated that ttCH exerts acute and chronic anti-inflammatory effects that may be related with the inhibition of iNOS expression.
Naunyn-schmiedebergs Archives of Pharmacology, 2003
We have previously investigated the effects of a series of dimethoxy- and trimethoxychalcone deri... more We have previously investigated the effects of a series of dimethoxy- and trimethoxychalcone derivatives, with various patterns of fluorination, on nitric oxide production in LPS-stimulated murine RAW 264.7. The present study was designed to determine if 3,4,5-trimethoxy-4'-fluorochalcone (CH 17) could modulate the production of NO and/or prostaglandins in vivo. On the mouse macrophage cell line RAW 264.7 CH 17 inhibited dose-dependently NO production, with an IC50 value in the nanomolar range, and reduced PGE2 levels by a 58% at 10 μM. This compound had no direct inhibitory effect on iNOS and COX-2 activities. NO reduction was the consequence of inhibition of the expression of iNOS. In vitro experiments indicated that CH 17 is an inhibitor of the nuclear factor-κB (NF-κB) pathway of cellular activation in macrophages. This compound exhibited in vivo an inhibitory behaviour correlated with its in vitro results on nitrite and PGE2 accumulation. In the rat adjuvant-induced arthritis, oral administration of CH 17 (25 mg/kg) on days 17–24 after adjuvant injection, significantly inhibited paw oedema, protected from weight loss and reduced the levels of inflammatory mediators (nitrites and PGE2) in paw homogenates, without affecting PGE2 levels in stomach homogenates. The profile and potency of this compound, a selective inhibitor of iNOS expression that interferes with NF-κB activation, may have relevance for the inhibition of the inflammatory response, representing a new approach to the modulation of different inflammatory pathologies.
A series of nine dimethylamino-chalcone derivatives (1,3-diaryl-propenones) was synthesized and s... more A series of nine dimethylamino-chalcone derivatives (1,3-diaryl-propenones) was synthesized and screened as potential inhibitors of NO and PGE2 production in the RAW 264.7 macrophage cell line. 4-Dimethylamino-2′,5′-dimethoxychalcone (6) was found to be the most potent and dual inhibitor (IC50s in the submicromolar range) of NO and PGE2 production. 2′,6′-Dimethoxylation appeared to be an effective requirement for selective and potent inhibition of nitric oxide synthase induction as it was confirmed by Western blot analysis. Chalcone (6) at 25 mg kg−1 by oral route, inhibited significantly the formation of oedema in the carrageenan-induced model of inflammation in mice.
3-(3-Pyridyl)-2-hydroxy-2-phosphonopropanoic acid (3-PEHPC, 1) is a phosphonocarboxylate (PC) ana... more 3-(3-Pyridyl)-2-hydroxy-2-phosphonopropanoic acid (3-PEHPC, 1) is a phosphonocarboxylate (PC) analogue of 2-(3-pyridyl)-1-hydroxyethylidenebis(phosphonic acid) (risedronic acid, 2), an osteoporosis drug that decreases bone resorption by inhibiting farnesyl pyrophosphate synthase (FPPS) in osteoclasts, preventing protein prenylation. 1 has lower bone affinity than 2 and weakly inhibits Rab geranylgeranyl transferase (RGGT), selectively preventing prenylation of Rab GTPases. We report here the synthesis and biological studies of 2-hydroxy-3-imidazo[1,2-a]pyridin-3-yl-2-phosphonopropionic acid (3-IPEHPC, 3), the PC analogue of minodronic acid 4. Like 1, 3 selectively inhibited Rab11 vs. Rap 1A prenylation in J774 cells, and decreased cell viability, but was 33-60Â more active in these assays. After resolving 3 by chiral HPLC (>98% ee), we found that (þ)-3-E1 was much more potent than (-)-3-E2 in an isolated RGGT inhibition assay, ∼17Â more potent (LED 3 μM) than (-)-3-E2 in inhibiting Rab prenylation in J774 cells and >26Â more active in the cell viability assay. The enantiomers of 1 exhibited a 4-fold or smaller potency difference in the RGGT and prenylation inhibition assays.
Esta ficha de estudio intenta facilitar el acceso a la lectura del ensayo "Imaginarios Sociales y... more Esta ficha de estudio intenta facilitar el acceso a la lectura del ensayo "Imaginarios Sociales y Sustentabilidad" de Enrique Leff. Este ensayo fue seleccionado como material de lectura para IESCA por haber sido considerado relevante para introducir la idea de imaginario social 3 en el estudio de las relaciones entre sociedad-cultura-naturaleza.
En el agua el O esta unido mediante enlaces covalentes simples a 2 átomos de H. Como el O es mas ... more En el agua el O esta unido mediante enlaces covalentes simples a 2 átomos de H. Como el O es mas electronegativo que el H, el par de e-compartido está desplazado hacia el núcleo de O. Se crea una nube o densidad (-) alrededor del O y una nube o densidad (+) alrededor del H. Se forma un polo positivo y uno negativo: dipolo.
FICHA DE CÁTEDRA: APORTES DEL PSICOANALISIS A LA REFLEXION SOBRE LA CULTURA: "EL MALESTAR EN LA C... more FICHA DE CÁTEDRA: APORTES DEL PSICOANALISIS A LA REFLEXION SOBRE LA CULTURA: "EL MALESTAR EN LA CULTURA" Sigmund Freud
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