1,805 research outputs found
Clays as Vehicles for Drug Photostability
This research was financially supported by Junta de Andalucia, under the project reference PT18 RT 3786.Clay minerals are often used due to their high adsorption capacity, which has sparked interest
in their biological applications to stabilize drugs and pharmaceutical products. This research aims
to summarize information about the stability of drugs, cosmetics, dermocosmetics, and pharmaceutical
compounds incorporated in the structure of different clay minerals. The databases used to search
the articles were Web of Science, Scopus, PubMed, and Science Direct. Photostabilization of these
compounds is reviewed and its importance demonstrated. For biological applications, the increase
in solubility and bioavailability of clay minerals has proven useful for them as drug carriers. While
their natural abundance, low toxicity, and accessible cost have contributed to classical applications
of clay minerals, a wide range of interesting new applications may be facilitated, mainly through
incorporating different organic molecules. The search for new functional materials is promising to
challenge research on clay minerals in biological or biotechnological approaches.Junta de Andalucia PT18 RT 378
Reproductive phenology of Carapa guianensis Aubl. (Meliaceae) in two forest areas of the Central Amazon
This article presents the phenological study of Carapa guianensis Aubl species from 1974 to 2000, in ADFR and TFES forests stations research in Central Amazon, Brazil. The objective was to analyze and compare the phenological pattern (flowering and fructification) and the influence of the climatic factors. The flowering in the TFES started in a higher precipitation season; meanwhile at ADFR it was irregular. The fruiting in both areas occurred more frequently rainiest season, but in the ADFR the mature fruits were more irregular. The frequency of occurrence was annual from âflower budâ to âimmature fruitâ phenophases in TFES, but was over-annual only in âmature fruitsâ. But in ADFR, was annual from âflower budâ to âanthesisâ and was over-annual in immature fruitâ and âmature fruitâ, both with irregular pattern and duration from intermediate to prolonged. The duration of the floral bud phenophase and anthesis was similar in the two areas; however, âimmature fruitsâ in the TFES, in general, was higher than in the ADFR. But âmature fruitsâ were higher in ADFR. The phenophases did not occurred at same time in all trees studied, possibly due the influence of the intraspecific genetic variability in interaction with the environment
InfluĂȘncia do nĂșmero de camadas na propriedade mecĂąnica de espĂ©cimes fabricados com atadura gessada usados para confeccionar splints ortopĂ©dicos
OBJECTIVE: To evaluate the effects of varying numbers of layers of plaster of Paris bandages on the mechanical properties of specimens used on the construction of orthopedic splints. METHODS: Rectangular plate-shaped and cylinder-shaped specimens were constructed and assigned to two groups simulating plaster slabs and cast and further divided into six subgroups according to the number of layers used: 3, 6, 8, 10, 12 and 14 layers. The specimens were subjected to either a three-point bending test (plates/slab) or compressive strength test (cylinders/cast). The following mechanical properties were evaluated: maximum load, elastic limit load and stiffness. Specimen weight was also calculated. Data was analyzed using Kruskal-Wallis and the least significant difference (LSD) tests. RESULTS: Pairwise comparisons of the subgroups 10x12 and 10x14 revealed significant differences for all mechanical properties (p<0.05). The results of this study suggest that when the goal is to construct appliances with high mechanical strength, regardless of weight, such as serial plaster slabs splints for stimulating tissue growth through the application of gradual load, splints made with plaster of Paris bandages with 12 or 14 layers should be preferred. For orthotic devices such as positioning orthotics, the use of 10 layers plaster bandages slab splints is advisable as they were found to have better correlation between mechanical strength and weight in comparison to those made wtih 6 or 8 layers. CONCLUSION: Based on the findings of this study, we suggest the use of 10 layers of plaster of Paris for the construction of orthopedic splints.OBJETIVO: Avaliar as propriedades mecĂąnicas de amostras fabricadas a partir de ataduras de gesso que sĂŁo utilizadas em Ăłrteses ortopĂ©dicas e que variam quanto ao nĂșmero de camadas. MĂTODOS: Foram confeccionados espĂ©cimes em forma de placa retangular e em forma cilĂndrica, divididos em dois grupos que simulavam splint e gesso circular, os quais foram divididos em seis subgrupos de acordo com o nĂșmero de camadas utilizadas, ou seja, trĂȘs, seis, oito, dez, 12 e 14 camadas. Os espĂ©cimes foram submetidos a um teste de inclinação de trĂȘs pontos (placas/splint) ou teste de resistĂȘncia Ă compressĂŁo (cilindros/gesso circular). As seguintes propriedades mecĂąnicas foram avaliadas: carga mĂĄxima e carga no limite de elasticidade e rigidez. O peso da amostra foi calculado. Os dados foram analisados estatisticamente pelos testes de Kruskal-Wallis e diferença mĂnima significativa (DMS). ComparaçÔes pareadas entre os subgrupos 10x12 e 10x14 revelaram diferenças significativas para todas as propriedades mecĂąnicas (p<0,05). RESULTADOS: Os resultados sugerem que, quando o objetivo Ă© construir aparelhos com alta resistĂȘncia mecĂąnica, independente do peso, tais como Ăłrteses seriadas de posicionamento para simular força gradual aplicada no tecido para a melhoria da amplitude de movimento, talas de 12 ou 14 camadas devem ser preferidas. Para os aparelhos ortopĂ©dicos que irĂŁo ser submetidos a esforços de baixa intensidade, aconselha-se a utilização de dez camadas para as Ăłrteses, porque houve uma melhor correlação entre a resistĂȘncia mecĂąnica e peso para as amostras fabricadas com dez camadas de atadura gessada comparadas com aquelas confeccionadas com seis ou oito camadas. CONCLUSĂO: Baseado nos achados deste estudo, sugere-se a utilização de dez camadas na confecção de Ăłrteses ortopĂ©dicas
Estudo reológico de polpa de caju em diferentes concentraçÔes.
Neste estudo foi avaliado o comportamento reolĂłgico de polpa de caju em diferentes concentraçÔes (5,5 a 25,0°Brix) na temperatura de 30°C. Os resultados indicaram um aumento da viscosidade com o aumento da concentração. A polpa de caju teve o comportamento de um fluido nĂŁo Newtoniano com caracterĂsticas pseudoplĂĄsticas. Palavras-chave: Anacardium occidentale L., reologia, viscosidade
Hydrodynamical simulations of the Sunyaev--Zel'dovich effect
We use a hydrodynamical N-body code to generate simulated maps, of size one
square degree, of the thermal SZ effect. We study three different cosmologies;
the currently-favoured low-density model with a cosmological constant, a
critical-density model and a low-density open model. We stack simulation boxes
corresponding to different redshifts in order to include contributions to the
Compton y-parameter out to the highest necessary redshifts. Our main results
are:
1. The mean y-distortion is around for low-density
cosmologies, and for critical density. These are below
current limits, but not by a wide margin in the former case.
2. In low-density cosmologies, the mean y-distortion comes from a broad range
of redshifts, the bulk coming from and a tail out to . For
critical-density models, most of the contribution comes from .
3. The number of SZ sources above a given depends strongly on instrument
resolution. For a one arcminute beam, there is around 0.1 sources per square
degree with in a critical-density Universe, and around 8 such
sources per square degree in low-density models. Low-density models with and
without a cosmological constant give very similar results.
4. We estimate that the {\sc Planck} satellite will be able to see of order
25000 SZ sources if the Universe has a low density, or around 10000 if it has
critical density.Comment: 9 pages LaTeX file with eleven figures (including four in colour)
incorporated (uses mn.sty and epsf). Further colour images and animations at
http://star-www.cpes.susx.ac.uk/~andrewl/sz/sz.html Updated to match
published versio
Islet neogenesis-associated protein signaling in neonatal pancreatic rat islets: Involvement of the cholinergic pathway
Islet neogenesis associated protein (INGAP) increases islet mass and insulin secretion in neonatal and adult rat islets. In the present study, we measured the short- and long-term effects of INGAP-PP (a pentadecapeptide having the 104-118 amino acid sequence of INGAP) upon islet protein expression and phosphorylation of components of the P13K, MAPK and cholinergic pathways, and on insulin secretion. Short-term exposure of neonatal islets to INGAP-PP (90 s, 5, 15, and 30 min) significantly increased Akt1-Ser473 and MAPK3/1-Thr202/ Tyr204 phosphorylation and INGAP-PP also acutely increased insulin secretion from islets perifused with 2 and 20 mM glucose. Islets cultured for 4 days in the presence of INGAP-PP showed an increased expression of Akt1, Frap1, and Mapk1 mRNAs as well as of the muscarinic M3 receptor subtype, and phospholipase C (PLC)-ÎČ2 proteins. These islets also showed increased Akt1 and MAPK3/1 protein phosphorylation. Brief exposure of INGAP-PP-treated islets to carbachol (Cch) significantly increased P70S6K-Thr389 and MAPK3/1 phosphorylation and these islets released more insulin when challenged with Cch that was prevented by the M3 receptor antagonist 4-DAMP, in a concentration-dependent manner. In conclusion, these data indicate that short- and long-term exposure to INGAP-PP significantly affects the expression and the phosphorylation of proteins involved in islet P13K and MAPK signaling pathways. The observations of INGAPP-PP-stimulated up-regulation of cholinergic M3 receptors and PLC- proteins, enhanced P70S6K and MAPK3/1 phosphorylation and Cch-induced insulin secretion suggest a participation of the cholinergic pathway in INGAP-PP-mediated effects.Facultad de Ciencias MĂ©dicasCentro de EndocrinologĂa Experimental y Aplicad
Hydrodynamical simulations of the SunyaevâZel'dovich effect: the kinetic effect
We use hydrodynamical N-body simulations to study the kinetic SunyaevâZel'dovich effect. We construct sets of maps, one square degree in size, in three different cosmological models. We confirm earlier calculations that on the scales studied the kinetic effect is much smaller than the thermal (except close to the thermal null point), with an rms dispersion smaller by about a factor of 5 in the RayleighâJeans region. We study the redshift dependence of the rms distortion and the pixel distribution at the present epoch. We compute the angular power spectra of the maps, including their redshift dependence, and compare them with the thermal SunyaevâZel'dovich effect and with the expected cosmic microwave background anisotropy spectrum as well as with determinations by other authors. We correlate the kinetic effect with the thermal effect both pixel-by-pixel and for identified thermal sources in the maps to assess the extent to which the kinetic effect is enhanced in locations of strong thermal signal
- âŠ