2,996 research outputs found
Energy Interpretation of Solar Radiation Affects for Artemisa Province
Solar energy is one of the renewable sources with the best prospects for the future, which can have used directly in two fundamental ways: thermal energy and photovoltaic solar energy. Photovoltaic systems are a viable alternative to diversify the energy base worldwide, being able to inject electrical energy into the grid. The work shows the study of the energy interpretation of solar radiation that affects the province of Artemisa, for its possible use in the generation of electricity, based on the introduction of photovoltaic systems connected to the electricity grid. A theoretical analysis is made about the solar potential and the influence of the climatic variables in the use of it, the territory of the Artemisa province is characterized, where the solar radiation for the generation of electricity is valued, the energy impact is evaluated. Derives from the use of solar radiation that affects the territory to generate electrical energy
Adaptive fractional PID control of biped robots with time-delayed feedback
This paper presents the application of Fractional Order Time- Delay adaptive neural networks to the trajectory tracking for chaos synchronization between Fractional Order delayed plant, reference and Fractional Order Time-Delay adaptive neural networks. The proposed new control scheme is applied via simulations to control of a 4-DOF Biped Robot [1]. The main methodologies, on which the approach is based, are Fractional Order PID the Fractional Order Lyapunov-Krasovskii functions methodology. The structure of the biped robot is designed with two degrees of freedom per leg, corresponding to the knee and hip joints. Since torso and ankle are not considered, it is obtained a 4-DOF system, and each leg, we try to force this biped robot to track a reference signal given by undamped Duffing equation. The tracking error is globally asymptotically stabilized by two control laws derived based on a Lyapunov-Krasovski functional
18F-FDG-PET Imaging Patterns in Autoimmune Encephalitis: Impact of Image Analysis on the Results
Brain positron emission tomography imaging with 18Fluorine-fluorodeoxyglucose
(FDG-PET) has demonstrated utility in suspected autoimmune encephalitis. Visual and/or
assisted image reading is not well established to evaluate hypometabolism/hypermetabolism.
We retrospectively evaluated patients with autoimmune encephalitis between 2003 and 2018.
Patients underwent EEG, brain magnetic resonance imaging (MRI), cerebrospinal fluid (CSF)
sampling and autoantibodies testing. Individual FDG-PET images were evaluated by standard
visual reading and assisted by voxel-based analyses, compared to a normal database. For the
latter, three different methods were performed: two based on statistical surface projections (Siemens
syngo.via Database Comparison, and 3D-SSP Neurostat) and one based on statistical parametric
mapping (SPM12). Hypometabolic and hypermetabolic findings were grouped to identify specific
patterns. We found six cases with definite diagnosis of autoimmune encephalitis. Two cases had
anti-LGI1, one had anti-NMDA-R and two anti-CASPR2 antibodies, and one was seronegative.
18F-FDG-PET metabolic abnormalities were present in all cases, regardless of the method of analysis.
Medial–temporal and extra-limbic hypermetabolism were more clearly depicted by voxel-based
analyses. We found autoantibody-specific patterns in line with the literature. Statistical surface
projection (SSP) methods (Neurostat and syngo.via Database Comparison) were more sensitive
and localized larger hypermetabolic areas. As it may lead to comparable and accurate results,
visual analysis of FDG-PET studies for the diagnosis of autoimmune encephalitis benefits from
voxel-based analysis, beyond the approach based on MRI, CSF sample and EEG
A simple analytical method for heterogeneity corrections in low dose rate prostate brachytherapy
In low energy brachytherapy, the presence of tissue heterogeneities contributes significantly to the discrepancies observed between treatment plan and delivered dose. In this work, we present a simplified analytical dose calculation algorithm for heterogeneous tissue. We compare it with Monte Carlo computations and assess its suitability for integration in clinical treatment planning systems. The algorithm, named as RayStretch, is based on the classic equivalent path length method and TG-43 reference data. Analytical and Monte Carlo dose calculations using Penelope2008 are compared for a benchmark case: a prostate patient with calcifications. The results show a remarkable agreement between simulation and algorithm, the latter having, in addition, a high calculation speed. The proposed analytical model is compatible with clinical real-time treatment planning systems based on TG-43 consensus datasets for improving dose calculation and treatment quality in heterogeneous tissue. Moreover, the algorithm is applicable for any type of heterogeneities
Phase behaviour of Ag2CrO4 under compression: Structural, vibrational, and optical properties
This document is the Accepted Manuscript version of a Published Work that appeared in final form in
Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher.
To access the final edited and published work see http://dx.doi.org/10.1021/jp401524sWe have performed an experimental study of the crystal structure, lattice dynamics, and optical properties of silver chromate (Ag2CrO4) at ambient temperature and high pressures. In particular, the crystal structure, Raman-active phonons, and electronic band gap have been accurately determined. When the initial orthorhombic Pnma Ag2CrO4 structure (phase I) is compressed up to 4.5 GPa, a previously undetected phase (phase II) has been observed with a 0.95% volume collapse. The structure of phase II can be indexed to a similar orthorhombic cell as phase I, and the transition can be considered to be an isostructural transition. This collapse is mainly due to the drastic contraction of the a axis (1.3%). A second phase transition to phase III occurs at 13 GPa to a structure not yet determined. First-principles calculations have been unable to reproduce the isostructural phase transition, but they propose the stabilization of a spinel-type structure at 11 GPa. This phase is not detected in experiments probably because of the presence of kinetic barriers. Experiments and calculations therefore seem to indicate that a new structural and electronic description is required to model the properties of silver chromate.This study was supported by the Spanish government MEC under grants MAT2010-21270-C04-01/03/04 and CTQ2009-14596-C02-01, by the Comunidad de Madrid and European Social Fund (S2009/PPQ1551 4161893), by the MALTA Consolider Ingenio 2010 project (CSD2007-00045), and by the Vicerrectorado de Investigacion y Desarrollo of the Universidad Politecnica de Valencia (UPV2011-0914 PAID-05-11 and UPV2011-0966 PAID-06-11). A.M. and P.R.-H. acknowledge computing time provided by Red Espanola de Supercomputacion (RES) and MALTA-Cluster. J.A.S. acknowledges Juan de la Cierva Fellowship Program for its financial support. Diamond and ALBA Synchrotron Light Sources are acknowledged for provisions of beam time. We also thank Drs. Peral, Popescu, and Fauth for technical support.Santamaría Pérez, D.; Bandiello, E.; Errandonea, D.; Ruiz-Fuertes, J.; Gomis Hilario, O.; Sans, JÁ.; Manjón Herrera, FJ.... (2013). Phase behaviour of Ag2CrO4 under compression: Structural, vibrational, and optical properties. Journal of Physical Chemistry C. 117(23):12239-12248. https://doi.org/10.1021/jp401524sS12239122481172
Effect of ABCB1 and ABCC3 Polymorphisms on Osteosarcoma Survival after Chemotherapy: A Pharmacogenetic Study
Standard treatment for osteosarcoma patients consists of a
combination of cisplatin, adriamycin, and methotrexate before surgical resection
of the primary tumour, followed by postoperative chemotherapy including
vincristine and cyclophosphamide. Unfortunately, many patients still relapse or
suffer adverse events. We examined whether common germline polymorphisms in
chemotherapeutic transporter and metabolic pathway genes of the drugs used in
standard osteosarcoma treatment may predict treatment response.
METHODOLOGY/PRINCIPAL FINDINGS: In this study we screened 102 osteosarcoma
patients for 346 Single Nucleotide Polymorphisms (SNPs) and 2 Copy Number
Variants (CNVs) in 24 genes involved in the metabolism or transport of cisplatin,
adriamycin, methotrexate, vincristine, and cyclophosphamide. We studied the
association of the genotypes with tumour response and overall survival. We found
that four SNPs in two ATP-binding cassette genes were significantly associated
with overall survival: rs4148416 in ABCC3 (per-allele HR = 8.14, 95%CI =
2.73-20.2, p-value = 5.1x10(-)(5)), and three SNPs in ABCB1, rs4148737
(per-allele HR = 3.66, 95%CI = 1.85-6.11, p-value = 6.9x10(-)(5)), rs1128503 and
rs10276036 (r(2) = 1, per-allele HR = 0.24, 95%CI = 0.11-0.47 p-value =
7.9x10(-)(5)). Associations with these SNPs remained statistically significant
after correction for multiple testing (all corrected p-values [permutation test]
</= 0.03). CONCLUSIONS: Our findings suggest that these polymorphisms may affect
osteosarcoma treatment efficacy. If these associations are independently
validated, these variants could be used as genetic predictors of clinical outcome
in the treatment of osteosarcoma, helping in the design of individualized
therapy
Compressibility systematics of calcite-type borates : An experimental and theoretical structural study on ABO3 (A = Al, Sc, Fe and In)
This document is the Accepted Manuscript version of a Published Work that appeared in final form in
Journal of Physical Chemistry C , copyright © American Chemical Society after peer review and technical editing by the publisher.
To access the final edited and published work see http://dx.doi.org/10.1021/jp4124259The structural properties of calcite-type orthoborates ABO(3) (A = Al, Fe, Sc, and In) have been investigated at high pressures up to 32 GPa. They were studied experimentally using synchrotron powder X-ray diffraction and theoretically by means of ab initio total-energy calculations. We found that the calcite-type structure remains stable up to the highest pressure explored in the four studied compounds. Experimental and calculated static geometries (unit-cell parameters and internal coordinates), bulk moduli, and their pressure derivatives are in good agreement. The compressibility along the c axis is roughly three times that along the a axis. Our data clearly indicate that the compressibility of borates is dominated by that of the [AO(6)] octahedral group and depends on the size of the trivalent A cations. An analysis of the relationship between isomorphic borates and carbonates is also presented, which points to the potentiality of considering borates as chemical analogues of the carbonate mineral family.This study was supported by the Spanish government MEC under Grant Nos.: MAT2010-21270-C04-01/03/04 and CTQ2009-14596-C02-01, by MALTA Consolider Ingenio 2010 Project (CSD2007-00045), by Generalitat Valenciana (GVA-ACOMP-2013-1012), and by the Vicerrectorado de Investigacion y Desarrollo of the Universidad Politecnica de Valencia (UPV2011-0914 PAID-05-11 and UPV2011-0966 PAID-06-11). We thank ALBA and Diamond synchrotrons for providing beamtime for the XRD experiments. A.M. and P.R-H. acknowledge computing time provided by Red Espanola de Supercomputacion (RES) and MALTA-Cluster. J.A.S. and B.G.-D. acknowledge Juan de la Cierva fellowship and FPI programs for financial support. We are gratefully indebted to Dr. Capponi and Dr. Diehl for supplying us single crystals of AlBO3 and FeBO3, respectively.Santamaría Pérez, D.; Gomis Hilario, O.; Sans, JÁ.; Ortiz, HM.; Vegas, Á.; Errandonea, D.; Ruiz-Fuertes, J.... (2014). Compressibility systematics of calcite-type borates : An experimental and theoretical structural study on ABO3 (A = Al, Sc, Fe and In). Journal of Physical Chemistry C. 118(8):4354-4361. https://doi.org/10.1021/jp4124259S43544361118
LYACOLORE: synthetic datasets for current and future Lyman-alpha forest BAO surveys
The statistical power of Lyman-α forest Baryon Acoustic Oscillation (BAO) measurements is set to increase significantly in the coming years as new instruments such as the Dark Energy Spectroscopic Instrument deliver progressively more constraining data. Generating mock datasets for such measurements will be important for validating analysis pipelines and evaluating the effects of systematics. With such studies in mind, we present LyaCoLoRe: a package for producing synthetic Lyman-α forest survey datasets for BAO analyses. LyaCoLoRe transforms initial Gaussian random field skewers into skewers of transmitted flux fraction via a number of fast approximations. In this work we explain the methods of producing mock datasets used in LyaCoLoRe, and then measure correlation functions on a suite of realisations of such data. We demonstrate that we are able to recover the correct BAO signal, as well as large-scale bias parameters similar to literature values. Finally, we briefly describe methods to add further astrophysical effects to our skewers—high column density systems and metal absorbers—which act as potential complications for BAO analyses
Cyclodextrin-grafted TiO2 nanoparticles: synthesis, complexation capacity, and dispersion in polymeric matrices
The modification of the surface of titanium dioxide nanoparticles (TiO2 NPs) by the incorporation of cyclodextrins (CDs), cyclic oligosaccharides with a hydrophobic cavity, can largely improve the functionality of TiO2 by lodging molecules of interest in the CD to act directly on the surface of the nanoparticles or for further release. With this aim, we have synthesized beta CD-modified nanoparticles (beta CDTiO2 NPs) by a two-step reaction that involves the incorporation of a spacer and then the linking of the macrocycle, and characterized them by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The capacity of the functionalized structures to trap model compounds (Rhodamine and 1-naphthol) has been compared to that of bare TiO2 NPs by fluorescence and Ultraviolet-visible (UV-visible) spectroscopy. The presence of the CDs on the surface of the TiO2 avoids the photo-degradation of the guest, which is of interest in order to combine the photocatalytic activity of TiO2, one of its most interesting features for practical purposes, with the delivery of compounds susceptible of being photo-degraded. The beta CDTiO2 NPs have been dispersed in polymeric matrices of frequently used polymers, polyethylene (LDPE) and polyethylene oxide (PEO), by cryogenic high energy ball milling to produce nanocomposites in the form of films. The surface modification of the nanoparticles favors the homogenization of the filler in the matrix, while the nanoparticles, either in bare or functionalized form, do not seem to alter the crystallization properties of the polymer at least up to a 5% (w/w) load of filler
A model based on the quantification of complement C4c, CYFRA 21-1 and CRP exhibits high specificity for the early diagnosis of lung cancer
Lung cancer screening detects early-stage cancers, but also a large number of benign nodules. Molecular markers can help in the lung cancer screening process by refining inclusion criteria or guiding the management of indeterminate pulmonary nodules. In this study, we developed a diagnostic model based on the quantification in plasma of complement-derived fragment C4c, cytokeratin fragment 21-1 (CYFRA 21-1) and C-reactive protein (CRP). The model was first validated in two independent cohorts, and showed a good diagnostic performance across a range of lung tumor types, emphasizing its high specificity and positive predictive value. We next tested its utility in two clinically relevant contexts: assessment of lung cancer risk and nodule malignancy. The scores derived from the model were associated with a significantly higher risk of having lung cancer in asymptomatic individuals enrolled in a computed tomography (CT)-screening program (OR = 1.89; 95% CI = 1.20–2.97). Our model also served to discriminate between benign and malignant pulmonary nodules (AUC: 0.86; 95% CI = 0.80–0.92) with very good specificity (92%). Moreover, the model performed better in combination with clinical factors, and may be used to reclassify patients with intermediate-risk indeterminate pulmonary nodules into patients who require a more aggressive work-up. In conclusion, we propose a new diagnostic biomarker panel that may dictate which incidental or screening-detected pulmonary nodules require a more active work-up
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