146 research outputs found
Forest edge herbaceous vegetation (Trifolio-Geranietea) of northern Spain
A survey of the vegetation of forest (and hedge) fringes, classified within the Trifolio-Geranietea, in the Basque Country and the western and central Pyrenees (northern Spain) is presented. Three plant associations can be distinguished: the Centaureo nemoralis-Origanetum vulgaris, the Agrimonio-Trifolietum medii (both on limerich substrates) and the Hyperico androsaemi-Teucrietum scorodoniae (typical of siliceous soils). The Centaureo nemoralis-Origanetum vulgaris has already been known from the Atlantic zone of France. The Agrimonio-Trifolietum medii was described for Central Europe and it was also found to be widespread in the Pyrenees. The Hyperico androsaemi-Teucrietum scorodoniae is a new syntaxon (described in this paper) and occurs in coastal regions of the Atlantic Basque Country (Santanderino-Vizcaino Subsector)
The stabilisation of receptor structure in low cross-linked MIPs by an immobilised template
In molecularly imprinted polymers (MIPs) a high level of cross-linking is
usually important for preserving the receptor structure. We propose here an
alternative approach for stabilising binding sites, which involves the use of an
immobilised template. The idea is based on the assumption that an immobilised
template will ‘‘hold’’ polymeric chains and complementary functionalities
together, preventing the collapsing of the binding sites. To test this
postulate, a range of polymers was prepared using polymerisable (2,4-diamino-6-
(methacryloyloxy)ethyl-1,3,5-triazine) and non-polymerisable (or extractable)
(2,4-diamino-6-methyl-1,3,5-triazine) templates, methacrylic acid as functional
monomer and ethylene glycol dimethacrylate as cross-linker. The level of cross-
linking was varied from 12 to 80%. Polymerisations were performed in
acetonitrile using UV initiation. Binding properties of the synthesised
materials were characterised both by HPLC and equilibrium batch binding
experiments followed by HPLC-MS or UV-visible detection. The adsorption
isotherms of polymers were obtained and fitted to the Langmuir model to
calculate dissociation constant, Kd, and concentration of binding sites for each
material. The results strongly indicate that the presence of an immobilised
template improves the affinity of MIPs containing low percentages of cross-
linker. The low cross-linked MIPs synthesised with a polymerisable template also
retain a reasonable degree of selectivity. Low crosslinked MIPs with such
binding characteristics would be useful for the creation of new types of optical
and electrochemical sensors, where induced fit or the ‘‘gate effect’’ could be
used more effectively for generating and enhancin
Adiciones a la pteridoflora de Tabasco, México: la importancia del bosque mesófilo de montaña
Background and Aims: The ejido Villa de Guadalupe of the municipality of Huimanguillo, Tabasco, contains the only fragment of humid montane forest in the state, which has been little explored floristically. This study is an addition to those previously published, where reports of new records increase considerably the richness of fern species known so far for Tabasco state. The main objective is to update the knowledge of the pteridophyte flora of this state, emphasizing the importance of the humid montane forest.Methods: Epiphytic and terrestrial fern collections were made randomly on the north and northeast face of the Las Flores mountain (450-1000 m a.s.l.) in the municipality of Huimanguillo. Specimens were identified mainly by dichotomous keys and distributed to national and foreign herbaria.Key results: A total of 64 species of ferns and lycopods were recorded. The best represented families were Polypodiaceae, Dryopteridaceae and Hymenophyllaceae. We highlight the records of 30 species that had not previously been reported in the state of Tabasco. Even of the genera Cochlidium, Elaphoglossum, Hypolepis, Odontosoria, Parapolystichum, Polytaenium, Saccoloma and Sphaeropteris, this is the first report for the state.Conclusions: The new additions to the pteridophyte flora of Tabasco lead to a count of 169 species for the state, which updates the information known so far (137 species) and shows the need of continued regional floristic inventories. The present study represents one of the few published papers that document the richness of a specific taxonomic group in the humid montane forest of the state.Antecedentes y Objetivos: El ejido Villa de Guadalupe del municipio Huimanguillo, Tabasco, mantiene el único fragmento de bosque mesófilo de montaña en el estado, mismo que ha sido florísticamente poco explorado. Este estudio se suma a otros anteriormente publicados, donde los reportes de nuevos registros aumentan considerablemente la riqueza de especies de helechos y licopodios conocidas hasta ahora para Tabasco. El objetivo principal es actualizar el conocimiento de la pteridoflora de la entidad, enfatizando la importancia del bosque mesófilo de montaña.Métodos: Se realizaron colectas al azar de helechos epífitos y terrestres en la cara norte y noreste del cerro Las Flores (450-1000 m s.n.m.) en el municipio Huimanguillo. Los especímenes fueron identificados principalmente mediante claves taxonómicas y distribuidos en herbarios nacionales y extranjeros.Resultados clave: Se registraron en total 64 especies de helechos y licopodios. Las familias mejor representadas fueron Polypodiaceae, Dryopteridaceae e Hymenophyllaceae. Se destaca el registro de 30 especies que no habían sido reportadas previamente en el estado de Tabasco. Para los géneros Cochlidium, Elaphoglossum, Hypolepis, Odontosoria, Parapolystichum, Polytaenium, Saccoloma y Sphaeropteris, este es el primer reporte para la entidad.Conclusiones: Las nuevas adiciones a la pteridoflora de Tabasco proporcionan un recuento de 169 especies para el estado, lo cual actualiza la información conocida hasta ahora (137 especies) y manifiesta la necesidad de continuar con la realización de inventarios florísticos regionales. El presente estudio representa uno de los pocos trabajos publicados que documentan la riqueza de un grupo taxonómico en específico en el bosque mesófilo de montaña del estado
A Patterned Butyl Methacrylate-co-2-Hydroxyethyl Acrylate Copolymer with Softening Surface and Swelling Capacity
The tunable swelling and mechanical properties of nanostructures polymers are crucial parameters for the creation of adaptive devices to be used in diverse fields, such as drug delivery, nanomedicine, and tissue engineering. We present the use of anodic aluminum oxide templates as a nanoreactor to copolymerize butyl methacrylate and 2-hydroxyethyl acrylate under radical conditions. The copolymer obtained under confinement showed significant differences with respect to the same copolymer obtained in bulk conditions. Molecular weights, molecular weight dispersities, Young’s modulus, and wetting behaviors were significantly modified. The combination of selected monomers allowed us to obtain nanopillar structures with an interesting softening surface and extraordinary swelling capacity that could be of special interest to surface science and specifically, cell culture.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada
Scale-dependent plant diversity in Palaearctic grasslands: a comparative overview
Here we present an extensive overview of plant diversity values in Palaearctic grasslands for seven standard grain sizes from 0.0001 to 100 m². The data originate from 20 studies, including the Field Workshops of the Eurasian Dry Grassland Group (EDGG), ranging geographically from Spain in the west to Siberia in the east, from Sicily in the south to Estonia in the north and from the sea coast up to 3100 m a.s.l. The majority of data is from dry grasslands (Festuco-Brometea, Koelerio-Corynephoretea, Cleistogenetea squarrosae), but there are also some mesic, wet, saline, acidic, alpine and Mediterranean grasslands included. Among others, we compiled data from 1795 1-m², 1109 10-m² and 338 100-m² plots. In all cases we present mean, minimum and maximum richness for the seven grain sizes, plus, in cases where also terricolous bryophytes and lichens had been recorded, the same values for total “plant” species richness, non-vascular plant species richness and fraction of non-vascular plants. The maximum richness values were 82, 101 and 134 for all “plants”, and 79, 98 and 127 vascular plants at grain sizes of 1 m², 10 m² and 100 m², respectively (all in Transylvania, Romania). Our overview comprises new, hitherto unpublished world records of vascular plant species richness at the scales of 0.0001 m² (9) and 0.001 m² (19, both shoot presence), from meso-xeric, basiphilous grasslands in Navarre, Spain, which is much higher than the previously known maxima. The highest values of non-vascular plant richness at 1 m², 10 m² and 100 m², respectively, were 49, 64 and 64, respectively (all in Sedo-Scleranthenea communities of Öland, Sweden, and Saaremaa, Estonia). In general, the dry, alpine and Mediterranean grasslands were much richer than the studied mesic, wet or saline grasslands at any spatial scale. The presented set of mean, minimum and maximum values and their metadata is publically available and will be continuously updated. These data can serve as a reference of “normal” richness, both in fundamental and applied research. To facilitate the application, we provide an easy formula based on the power-law species-area relationship that allows the estimation of richness values at intermediate grain sizes not included in our dataset. In conclusion, our data emphasise the role of Palaearctic grasslands as global hotspot of small-scale vascular plant diversity, while at the same time highlighting that in some grassland types also the bryophyte and lichen diversity can be extraordinarily high
Optimisation of the synthesis of vancomycin-selective molecularly imprinted polymer nanoparticles using automatic photoreactor
Effect of SGLT2 inhibitors on stroke and atrial fibrillation in diabetic kidney disease: Results from the CREDENCE trial and meta-analysis
BACKGROUND AND PURPOSE: Chronic kidney disease with reduced estimated glomerular filtration rate or elevated albuminuria increases risk for ischemic and hemorrhagic stroke. This study assessed the effects of sodium glucose cotransporter 2 inhibitors (SGLT2i) on stroke and atrial fibrillation/flutter (AF/AFL) from CREDENCE (Canagliflozin and Renal Events in Diabetes With Established Nephropathy Clinical Evaluation) and a meta-Analysis of large cardiovascular outcome trials (CVOTs) of SGLT2i in type 2 diabetes mellitus. METHODS: CREDENCE randomized 4401 participants with type 2 diabetes mellitus and chronic kidney disease to canagliflozin or placebo. Post hoc, we estimated effects on fatal or nonfatal stroke, stroke subtypes, and intermediate markers of stroke risk including AF/AFL. Stroke and AF/AFL data from 3 other completed large CVOTs and CREDENCE were pooled using random-effects meta-Analysis. RESULTS: In CREDENCE, 142 participants experienced a stroke during follow-up (10.9/1000 patient-years with canagliflozin, 14.2/1000 patient-years with placebo; hazard ratio [HR], 0.77 [95% CI, 0.55-1.08]). Effects by stroke subtypes were: ischemic (HR, 0.88 [95% CI, 0.61-1.28]; n=111), hemorrhagic (HR, 0.50 [95% CI, 0.19-1.32]; n=18), and undetermined (HR, 0.54 [95% CI, 0.20-1.46]; n=17). There was no clear effect on AF/AFL (HR, 0.76 [95% CI, 0.53-1.10]; n=115). The overall effects in the 4 CVOTs combined were: Total stroke (HRpooled, 0.96 [95% CI, 0.82-1.12]), ischemic stroke (HRpooled, 1.01 [95% CI, 0.89-1.14]), hemorrhagic stroke (HRpooled, 0.50 [95% CI, 0.30-0.83]), undetermined stroke (HRpooled, 0.86 [95% CI, 0.49-1.51]), and AF/AFL (HRpooled, 0.81 [95% CI, 0.71-0.93]). There was evidence that SGLT2i effects on total stroke varied by baseline estimated glomerular filtration rate (P=0.01), with protection in the lowest estimated glomerular filtration rate (45 mL/min/1.73 m2]) subgroup (HRpooled, 0.50 [95% CI, 0.31-0.79]). CONCLUSIONS: Although we found no clear effect of SGLT2i on total stroke in CREDENCE or across trials combined, there was some evidence of benefit in preventing hemorrhagic stroke and AF/AFL, as well as total stroke for those with lowest estimated glomerular filtration rate. Future research should focus on confirming these data and exploring potential mechanisms
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