3,070 research outputs found
Theory of extraordinary transmission of light through quasiperiodic arrays of subwavelength holes
By using a theoretical formalism able to work in both real and k-spaces, the
physical origin of the phenomenon of extraordinary transmission of light
through quasi-periodic arrays of holes is revealed. Long-range order present in
a quasiperiodic array selects the wavevector(s) of the surface electromagnetic
mode(s) that allows an efficient transmission of light through subwavelength
holes.Comment: 4 pages, 4 figure
Highly perturbed molecular gas in infalling cluster galaxies : the case of CGCG97-079
Date of Acceptance: 14/07/2015We report on CO (J = 2 → 1) mapping with the IRAM 30-m HEtrodyne Receiver Array (HERA) of CGCG 97-079, an irregular galaxy in the merging galaxy cluster Abell 1367 (z = 0.022). We find that ˜80 per cent of the detected CO (J = 2 → 1) is projected within a 16 arcsec2 (6.5 kpc2) region to the north and west of the optical/NIR centre, with the intensity maximum offset ˜10 arcsec (4 kpc) NW of the optical/NIR centre and ˜7 arcsec (3 kpc) south-east of the H I intensity maximum. Evolutionary synthesis models indicate CGCG 97-079 experienced a burst of star formation ˜108 yr ago, most likely triggered by a tidal interaction with CGCG 97-073. For CGCG 97-079 we deduce an infall velocity to the cluster of ˜1000 km s-1 and moderate ram pressure (Pram ≈ 10-11 dyne cm-2). The observed offset in CGCG 97-079 of the highest density H I and CO (J = 2 → 1) from the stellar components has not previously been observed in galaxies currently undergoing ram pressure stripping, although previous detailed studies of gas morphology and kinematics during ram pressure stripping were restricted to significantly more massive galaxies with deeper gravitational potential wells. We conclude the observed cold gas density maxima offsets are most likely the result of ram pressure and/or the high-speed tidal interaction with CGCG 97-073. However ram pressure stripping is likely to be playing a major role in the perturbation of lower density gas.Peer reviewe
Nacimiento de una masa mixta: regeneración del pino salgareño tras aplicar resalveos de distinto peso en tallares envejecidos de encina en el centro peninsular
En este trabajo se presentan los resultados obtenidos tras ejecutar resalveos de conversion de diferente peso en un tallar envejecido de encina (Quercus ilex subsp. ballota) situado en Guadalajara. El dispositivo experimental se instaló e inventarió en 1994. En 1995 se aplicaron resalveos de pesos variables entre 0 % (control) y 100 % de area basimétrica extraída. En 2010 se han realizado nuevos inventarios, encontrando una abundante egeneración de Pinus nigra a partir de pinos adultos dispersos en la zona de estudio. Dicha regeneración está significativamente relacionada con los pesos de clara aplicados y con la proximidad de pinos adultos de grandes diámetros
Factores microclimáticos que afectan a la regeneración de Pinus pinaster Ait. en Tierra de Pinares (Segovia)
El objetivo de este estudio fue evaluar los factores micrometeorológicos que afectan a la regeneración del pino resinero en la Tierra de Pinares Segoviana. Se registró durante un período vegetativo completo la temperatura del suelo y la temperatura de la capa de aire más próximo al suelo. La temperatura del suelo alcanzó máximos de 56 ºC desde el mes de julio a septiembre, en períodos de más de 4 horas seguidas durante 2-5 días consecutivos y la temperatura del aire más próximo al suelo, donde viven las plántulas recién nacidas, alcanzó valores de hasta 56 ºC desde junio a septiembre, durante períodos de más de 4,5 horas en periodos de 7 días consecutivos. En las plántulas objeto de estudio se identificaron heridas en el cuello de la raíz lo que indica que las altas temperaturas producen cambios fisiológicos y morfológicos en las plántulas comprometiendo su supervivencia y la de la regeneración de estos montes. El análisis estadístico mostró que los puntos de muestreo seleccionados no presentaron grandes diferencias respecto a las variables microclimáticas consideradas
Low threshold lasing emissions from a single upconversion nanocrystal.
Cross-relaxation among neighboring emitters normally causes self-quenching and limits the brightness of luminescence. However, in nanomaterials, cross-relaxation could be well-controlled and employed for increasing the luminescence efficiency at specific wavelengths. Here we report that cross-relaxation can modulate both the brightness of single upconversion nanoparticles and the threshold to reach population inversion, and both are critical factors in producing the ultra-low threshold lasing emissions in a micro cavity laser. By homogenously coating a 5-μm cavity with a single layer of nanoparticles, we demonstrate that doping Tm3+ ions at 2% can facilitate the electron accumulation at the intermediate state of 3H4 level and efficiently decrease the lasing threshold by more than one order of magnitude. As a result, we demonstrate up-converted lasing emissions with an ultralow threshold of continuous-wave excitation of ~150 W/cm2 achieved at room temperature. A single nanoparticle can lase with a full width at half-maximum as narrow as ~0.45 nm
Use of cinacalcet for the management of hyperparathyroidism in patients with different degrees of renal failure
Background: The effects of cinacalcet in persistent and/or hypercalcaemia-associated secondary hyperparathyroidism (SHPT) have been described in patients on dialysis.
Objectives: To evaluate the efficacy and safety of cinacalcet in SHPT not on dialysis and its effects on bone turnover markers.
Methods: Non-randomised, longitudinal, observational, analytical study of patients with chronic kidney disease (CKD) and SHPT (PTH> 80 pg/mL) as well as normo- or hypercalcaemia (≥8.5mg/dL), treated with cinacalcet.
Results: Mean cinacalcet dose was 30mg/day in 66.7%. We studied 15 patients (10 women), aged 66.0±17.93years. The aetiology was unknown in 20% of cases. Sociodemographic variables and renal function parameters were recorded. We compared values at baseline as well as after 6 and 12 months. Calcium (10.3±0.55 vs. 9.4±1.04) and iPTH (392.4±317.65 vs. 141.8±59.26) levels decreased. Increased levels of phosphorus (3.7±1.06 vs. 3.9±0.85) and ß-CTX (884.2±797.22 vs. 1053.6±999.00) were detected, although there were no significant changes in GFR, urinary calcium or other bone markers. Two patients withdrew from the study (gastrointestinal intolerance and parathyroidectomy, respectively).
Conclusions: Cinacalcet at low doses is effective in the management of SHPT in CKD patients who are not on dialysis. Its use reduces iPTH and calcaemia, without causing serious side effects or significant changes in renal function.
Keywords: Bone turnover markers; Calcio; Calcium; Chronic kidney disease; Cinacalcet; Enfermedad renal crónica; Fósforo; Hiperparatiroidismo secundario; Hormona paratiroidea; Marcadores de recambio óseo; Parathyroid hormone; Phosphorus; Secondary hyperparathyroidism
Molecular Characterization of Growth Hormone-producing Tumors in the GC Rat Model of Acromegaly
D.A.C. was supported by the Nicolás Monardes
program of the Andalusian Ministry of Health (C-0015-2014) and by a grant from the Andalusian
Ministry of Science and Innovation (CTS-7478). A.S-M and A.L.C were supported by grants from
the ISCIII-Subdirección General de Evaluación y Fomento de la Investigación co-funded with Fondos
FEDER (PI12/0143 and PI13/02043, respectively) and the Andalusian Regional Government (CTS-444)
and a grant from Pfizer Spain. R.L.C. was supported by a grant from Andalusian Ministry of Health
(PI0302-2012). R.M.L. was supported by grants from Proyecto de Investigación en Salud (FIS) PI13-
00651 (funded by Instituto de Salud Carlos III), CTS-1406, PI-0639-2012, BIO-0139 (funded by Junta
de Andalucía) and by Ayuda Merck Serono 2013. J. P. C. was funded by a grant (BFU2013-43282-R)
from Ministerio de Economía y Competitividad. CIBER is an initiative of Instituto de Salud Carlos III,
Ministerio de Sanidad, Servicios Sociales e Igualdad, Spain. J.F.M.R. is supported by the “Sara Borrell”
program from the Instituto de Salud Carlos III. R.M. Luque and J.P. Castaño have received grants and
lecture fees from Ipsen and Novartis. E. Venegas-Moreno and A. Soto-Moreno received grants and lecture
fees from Ipsen, Novartis and Pfizer. A. Leal-Cerro received grants from Novartis and Pfizer. David
Cano received a grant from Novartis
Controlled delivery of tauroursodeoxycholic acid from biodegradable microspheres slows retinal degeneration and vision loss in P23H rats
Successful drug therapies for treating ocular diseases require effective concentrations of neuroprotective compounds maintained over time at the site of action. The purpose of this work was to assess the efficacy of intravitreal controlled delivery of tauroursodeoxycholic acid (TUDCA) encapsulated in poly(D, L-lactic-co-glycolic acid) (PLGA) microspheres for the treatment of the retina in a rat model of retinitis pigmentosa. PLGA microspheres (MSs) containing TUDCA were produced by the O/W emulsion-solvent evaporation technique. Particle size and morphology were assessed by light scattering and scanning electronic microscopy, respectively. Homozygous P23H line 3 rats received a treatment of intravitreal injections of TUDCA-PLGA MSs. Retinal function was assessed by electroretinography at P30, P60, P90 and P120. The density, structure and synaptic contacts of retinal neurons were analyzed using immunofluorescence and confocal microscopy at P90 and P120. TUDCA-loaded PLGA MSs were spherical, with a smooth surface. The production yield was 78%, the MSs mean particle size was 23 mu m and the drug loading resulted 12.5 +/- 0.8 mu g TUDCA/mg MSs. MSs were able to deliver the loaded active compound in a gradual and progressive manner over the 28-day in vitro release study. Scotopic electroretinografic responses showed increased ERG a- and b-wave amplitudes in TUDCA-PLGA-MSstreated eyes as compared to those injected with unloaded PLGA particles.TUDCA-PLGAMSs- treated eyes showed more photoreceptor rows than controls. The synaptic contacts of photoreceptors with bipolar and horizontal cells were also preserved in P23H rats treated with TUDCA-PLGA MSs. This work indicates that the slow and continuous delivery of TUDCA from PLGA-MSs has potential neuroprotective effects that could constitute a suitable therapy to prevent neurodegeneration and visual loss in retinitis pigmentosa
Community-curated and standardised metadata of published ancient metagenomic samples with AncientMetagenomeDir
Ancient DNA and RNA are valuable data sources for a wide range of disciplines. Within the field of ancient metagenomics, the number of published genetic datasets has risen dramatically in recent years, and tracking this data for reuse is particularly important for large-scale ecological and evolutionary studies of individual microbial taxa, microbial communities, and metagenomic assemblages. AncientMetagenomeDir (archived at https://doi.org/10.5281/zenodo.3980833) is a collection of indices of published genetic data deriving from ancient microbial samples that provides basic, standardised metadata and accession numbers to allow rapid data retrieval from online repositories. These collections are community-curated and span multiple sub-disciplines in order to ensure adequate breadth and consensus in metadata definitions, as well as longevity of the database. Internal guidelines and automated checks to facilitate compatibility with established sequence-read archives and term-ontologies ensure consistency and interoperability for future meta-analyses. This collection will also assist in standardising metadata reporting for future ancient metagenomic studies.Competing Interest StatementThe authors have declared no competing interest.Background & Summary Methods - Repository Structure - Data Acquisition - Data Validation Data Records Technical Validation Usage Note
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