We performed a time-resolved spectroscopic study of the VUV/UV scintillation of gaseous argon as a function of pressure and electric field, by means of a wavelength sensitive detector operated with ...different radioactive sources. Our work conveys new evidence of distinctive features of the argon light which are in contrast with the general assumption that, for particle detection purposes, the scintillation can be considered to be largely monochromatic at 128 nm (second continuum). The wavelength and time-resolved analysis of the photon emission reveal that the dominant component of the argon scintillation during the first tens of ns is in the range 160, 325 nm. This light is consistent with the third continuum emission from highly charged argon ions/molecules. This component of the scintillation is field-independent up to 25 V/cm/bar and shows a very mild dependence with pressure in the range 1, 16 bar. The dynamics of the second continuum emission is dominated by the excimer formation time, whose variation as a function of pressure has been measured. Additionally, the time and pressure-dependent features of electron-ion recombination, in the second continuum band, have been measured. This study opens new paths toward a novel particle identification technique based on the spectral information of the noble-elements scintillation light.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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In the recent decades, various controlled delivery systems have been introduced with the aim to improve solubility, stability and bioavailability of poorly absorbed drugs. Among all, ...lipid nanoparticles gather interesting properties as drug or gene delivery carriers. These systems, composed either of solid lipids (SLN) or of solid and liquid lipids (NLC) stabilized with surfactants, combine the advantages of other colloidal particles such as polymeric nanoparticles, fat emulsions and liposomes avoiding their main disadvantages. Lipid nanoparticles represent an interesting approach for eye drug delivery as they can improve the corneal absorption of drugs enhancing their bioavailability. The Generally Recognized as Safe status of formulation excipients, the scaling-up facilities and the possibility of sterilization, make them suitable for industrial production. In this review, the latest findings, potential applications, and challenges related to the use of lipid nanoparticles for ocular drug delivery are comprehensively discussed.
Abstract
The Physics of the Accelerating Universe Survey (PAUS) is an innovative photometric survey with 40 narrow-bands at the William Herschel Telescope (WHT). The narrow-bands are spaced at 100 Å ...intervals covering the range 4500–8500 Å and, in combination with standard broad-bands, enable excellent redshift precision. This paper describes the technique, galaxy templates, and additional photometric calibration used to determine early photometric redshifts from PAUS. Using bcnz2, a new photometric redshift code developed for this purpose, we characterize the photometric redshift performance using PAUS data on the COSMOS field. Comparison to secure spectra from zCOSMOS DR3 shows that PAUS achieves σ68/(1 + $z$) = 0.0037 to iAB < 22.5 for the redshift range 0 < $z$ < 1.2, when selecting the best 50 per cent of the sources based on a photometric redshift quality cut. Furthermore, a higher photo-z precision σ68/(1 + $z$) ∼ 0.001 is obtained for a bright and high-quality selection, which is driven by the identification of emission lines. We conclude that PAUS meets its design goals, opening up a hitherto uncharted regime of deep, wide, and dense galaxy survey with precise redshifts that will provide unique insights into the formation, evolution, and clustering of galaxies, as well as their intrinsic alignments.
Conventional mode locking is characterized by the generation of a stable train of optical pulses. Even in the noise-like pulsing regime of fiber lasers, sometimes described as partial mode locking, a ...periodic train of waveforms is still generated. In this work we study the dynamics of a figure-eight fiber laser away from the stable noise-like pulsing regime. By analyzing sequences of time-domain measurements performed with ns resolution, we reveal a wide range of puzzling dynamics, in which sub-structures emerge and drift away from the main bunch, decay or grow in a step-like manner, before vanishing abruptly. In some cases, sub-packets also concentrate in the central part of the period, forming one or multiple wide clouds that merge or split over time scales of seconds or minutes. Spontaneous transitions between these multiple states occur in a non-periodic manner, so that no quasi-stationary behavior is found over long time scales. These results provide a dramatic illustration of the extremely rich dynamics taking place in fiber lasers at the frontier of mode locking.
En las sociedades desarrolladas existe una aceleración secular del crecimiento. Entre los años 2000 y 2004 hemos valorado el crecimiento en una población caucásica española procedente de Andalucía, ...Barcelona, Bilbao y Zaragoza y hemos comparado los resultados con estudios españoles realizados antes de 1988 en poblaciones caucásicas de Bilbao (BIB 88) y Cataluña (CAT 87).
Estudio transversal que valora el peso, la longitud y el índice de masa corporal (IMC) en 32.064 sujetos (16.607 varones y 15.457 mujeres) desde el nacimiento a la talla adulta: a) 5.796 son recién nacidos a término (2.974 varones y 2.822 mujeres) hijos de madres sanas, de gestaciones únicas; b) 23.701 son niños y adolescentes (12.358 varones y 11.343 mujeres) de 0,25 a 18 años de edad ambos inclusive, y c) 2.567 son adultos jóvenes (1.275 varones y 1.292 mujeres) de 18,1 a 24 años de edad. Todos estaban sanos, eran de raza caucásica y sus padres, de origen español. La distribución percentilada, el valor z-score y el diseño de las gráficas se ha realizado según el método LMS.
Se expresan los valores de la media, desviación estándar, coeficiente de Skewness y percentiles desde el nacimiento la edad adulta, en intervalos de 0,25-0,50 años. Existe un dimorfismo sexual y un incremento en los valores de peso y talla de todos los percentiles respecto a los estudios BIB 88 y CAT 87. Los valores de los percentiles 3, 50 y 97 de la talla adulta son superiores en 1,8, 1,4 y 3,3 cm respecto a BIB 88, y en 2,5, 3,3 y 3,8 cm respecto a CAT 87 en los varones, y 3,5, 2,5 y 4,2 cm respecto a BIB 88 y 3,5, 3,1 y 3,9 cm respecto a CAT 87 en las mujeres. Los correspondientes valores de peso son 5,4, 6,2 y 11,7 kg superiors a los de BIB 88 y 6,7, 6,3 y 10,1 kg superiores a los de CAT 87 en los varones y 1,7, 2,2 y 8,3 kg superiores a los de BIB 88, y 1,8, 2,4 y 3,6 kg superiores CAT 87 en las mujeres. Los respectivos incrementos en el IMC son 2,0, 1,4 y 3,9 respecto a BIB 88 y −0,1, −0,2 y 5,3 respecto a CAT 87 en los varones y 0,9, 0,4 y 3,7 respecto a BIB 88 y −1,8, −0,1 y 4,0 respecto a CAT 87, en las mujeres. Los valores del IMC de 25 y 30 “en la edad adulta” corresponden a los percentiles 80 y 97 en los varones y 85 y 97 en las mujeres.
En ambos sexos los valores de la talla media adulta son similares a los observados en otros estudios longitudinales y transversales españoles recientes y a los observados en estudios europeos y americanos, aunque inferiores a los de la población alemana, sueca y holandesa.
Con relación a estudios españoles previos, existe una aceleración secular de peso y talla, con un incremento desproporcionado en los valores del IMC correspondientes al percentil 75 o superiores, y de forma marcada en los del percentil 97. Este estudio muestra la necesidad de actualizar periódicamente los datos de referencia utilizados en la valoración del crecimiento durante la infancia y adolescencia.
In developed countries a secular trend in growth has been reported. Our aim was to evaluate weight, height and body mass index (BMI) values in a Spanish population coming from Andalusia, Barcelona, Bilbao and Zaragoza, and to compare these values with those obtained before 1988 (BIB 88 and CAT 87 studies).
Cross-sectional evaluation of height, weight and BMI in 32,064 subjects (16,607 males and 15,457 females) from birth to adulthood between the years 2000 and 2004. Three subpopulations were evaluated: a) 5,796 (2,974 males, 2,822 females) newborns at term from normal gestations; b) 23,701 (12,358 males; 11,343 females) children and adolescents 0.25-18 years old, and c) 2,567 (1,275 males, 1,292 females) young adults 18.1-24 years of age. All were healthy caucasians, and their parents from Spanish origin. The LSM method was used.
Mean, standard deviation, Skewness index and percentiles values with a 0.25-0.5 year-period intervals from birth to adulthood are reported. As regards the data obtained previously in Spanish populations, an increase of 1.8 cm, 1.4 cm and 3.3 cm were observed in adult height for percetiles 3, 50 and 97 in males respect to BIB 88 and 2.5 cm, 3.3 cm and 3.8 respect to CAT 87. In females these values were 3.5 cm, 2.5 cm and 4.2 cm respect to BIB 88 and 3.5 cm, 3.1 cm and 3.9 cm respect to CAT 87. The corresponding values for weight, in males, were increased in 5.4 kg, 6.2 kg and 11.7 kg respect to BIB 88 and 6.7 kg, 6.3 kg and 10.1 kg respect to CAT 87; in females these increased were 1.7 kg, 2,2 kg and 8.3 kg respect to BIB 88 and 1.8 kg, 2.4 kg and 3.6 kg respect to CAT 87. The corresponding increased for BMI values, in males, were 2.0, 1.4 and 3.9 respect to BIB 88 and −0.1, −0.2 and 5.3 respect to CAT 87; in females these values were 0.9, 0.4 and 3.7 respect to BIB 88 and −1.8, −0.1 and 4 respect to CAT 87. In young adults, 25 and 30 BMI values correspond to percentiles 80 and 97 in males, and 85 and 97 in females.
Mean values of adult height were similar to those observed in other longitudinal and cross-sectional Spanish, European, and American studies, but lower than those reported for German, Swedish and Netherlands populations.
A secular trend of growth was observed in our population with a non-proportional increased of weight to height ratio (BMI) values, particularly for those corresponding to the 97 percentile. The need of periodical updates of growth data used in the evaluation of children and adolescents is required.
To determine if a novel analysis method will increase the diagnostic value of the multifocal electroretinogram (mfERG) in diagnosing early-stage multiple sclerosis (MS).
We studied the mfERG signals ...of OD (Oculus Dexter) eyes of fifteen patients diagnosed with early-stage MS (in all cases < 12 months) and without a history of optic neuritis (ON) (F:M = 11:4), and those of six controls (F:M = 3:3). We obtained values of amplitude and latency of N1 and P1 waves, and a method to assess normalized root-mean-square error (FNRMSE) between model signals and mfERG recordings was used. Responses of each eye were analysed at a global level, and by rings, quadrants and hemispheres. AUC (area under the ROC curve) is used as discriminant factor.
The standard method of analysis obtains further discrimination between controls and MS in ring R3 (AUC = 0.82), analysing N1 waves amplitudes. In all of the retina analysis regions, FNRMSE value shows a greater discriminating power than the standard method. The highest AUC value (AUC = 0.91) was in the superior temporal quadrant.
By analysing mfERG recordings and contrasting them with those of healthy controls it is possible to detect early-stage MS in patients without a previous history of ON.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Al7075–graphite composites were synthesized by mechanical alloying and hot extrusion.•Effects of graphite content and milling time on the mechanical and wear properties of fabricated composites were ...analyzed.•Microstructure and worn surfaces of samples were studied by transmission and scanning electron microscope.•The friction coefficient, wear rate and debris thickness of fabricated composite were investigated.
Aluminum matrix composites (AMCs) are candidate materials for aerospace and automotive industry owing to their large elastic modulus, improved strength and low wear rate. A simple method for fabrication of Al7075–graphite composites produced by mechanical alloying (MI) and hot extrusion is described in this paper. Effects of milling time (0–10h) and graphite concentration (0–1.5wt.%) on friction, hardness and wear resistance of the AMC were investigated. Wear resistance was determined by the pin-on-disk wear method using 20 and 40N normal loads at a 0.367m/s sliding velocity. The worn surfaces were examined by scanning electron microscopy (SEM) to identify distinct topographical features for elucidation of the prevailing wear mechanisms. Experimental results indicated considerable improvement in AMC hardness and wear resistance by adding 1.5% G (wt.) and 10h of milling, showing homogenous distribution of the reinforcement particles in the Al-base metal-matrix composite. It was found that abrasion is the dominant wear mechanism in all extruded composites, whilst a combination of adhesion and delamination seems to be the governing mechanism for the 7075 aluminum alloy.
Little is known about targeting the metabolome in non-cancer conditions. Choline kinase (ChoKα), an essential enzyme for phosphatidylcholine biosynthesis, is required for cell proliferation and has ...been implicated in cancer invasiveness. Aggressive behaviour of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA) led us to evaluate whether this metabolic pathway could play a role in RA FLS function and joint damage.
Choline metabolic profile of FLS cells was determined by (1)H magnetic resonance spectroscopy ((1)HMRS) under conditions of ChoKα inhibition. FLS function was evaluated using the ChoKα inhibitor MN58b (IC₅₀=4.2 μM). For arthritis experiments, mice were injected with K/BxN sera. MN58b (3 mg/kg) was injected daily intraperitoneal beginning on day 0 or day 4 after serum administration.
The enzyme is expressed in synovial tissue and in cultured RA FLS. Tumour necrosis factor (TNF) and platelet-derived growth factor (PDGF) stimulation increased ChoKα expression and levels of phosphocholine in FLS measured by Western Blot (WB) and metabolomic studies of choline-containing compounds in cultured RA FLS extracts respectively, suggesting activation of this pathway in RA synovial environment. A ChoKα inhibitor also suppressed the behaviour of cultured FLS, including cell migration and resistance to apoptosis, which might contribute to cartilage destruction in RA. In a passive K/BxN arthritis model, pharmacologic ChoKα inhibition significantly decreased arthritis in pretreatment protocols as well as in established disease.
These data suggest that ChoKα inhibition could be an effective strategy in inflammatory arthritis. It also suggests that targeting the metabolome can be a new treatment strategy in non-cancer conditions.
An investigation was conducted on aluminum samples (AA1050) to study the microstructure and hardness evolution during processing by High Pressure Torsion Extrusion (HPTE). The equivalent strain ...accumulated in the samples after one pass of HPTE varied in a wide range between 0.9 and 65.5, depending on the processing parameters. HPTE led to the formation of a gradient microstructure in which the grain size decreased by increasing the distance from the central axis of the billets. This gradient decreased significantly by increasing the ratio of rotational speed to extrusion speed. Most of the grain refinement and hardness-increase occurred up to the equivalent strain of ~5 but saturation level was achieved at the strain of ~20. Saturation levels in grain size and hardness were ~0.7 μm and ~67 HV, respectively. HPTE technique can provide similar saturation in microstructure and hardness as those obtained by HPT but in much larger samples. Therefore, HPTE can be a named as a suitable candidate for practical applications to produce bulk ultrafine-grained materials with considerable enhancement in hardness.
ABSTRACT
In this paper, we introduce the deepz deep learning photometric redshift (photo-z) code. As a test case, we apply the code to the PAU survey (PAUS) data in the COSMOS field. deepz reduces ...the σ68 scatter statistic by 50 per cent at iAB = 22.5 compared to existing algorithms. This improvement is achieved through various methods, including transfer learning from simulations where the training set consists of simulations as well as observations, which reduces the need for training data. The redshift probability distribution is estimated with a mixture density network (MDN), which produces accurate redshift distributions. Our code includes an autoencoder to reduce noise and extract features from the galaxy SEDs. It also benefits from combining multiple networks, which lowers the photo-z scatter by 10 per cent. Furthermore, training with randomly constructed coadded fluxes adds information about individual exposures, reducing the impact of photometric outliers. In addition to opening up the route for higher redshift precision with narrow bands, these machine learning techniques can also be valuable for broad-band surveys.
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