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Background: To study the possible dosimetric benefits of a Hybrid planning technique that consists of combining intensity modulated radiotherapy (IMRT) and volumetric arc therapy (VMAT) for whole brain radiation therapy hippocampal-sparing (WBRTHS). Materials and Methods: Three types of plans were made for 15 patients, namely Hybrid, pure IMRT, and pure VMAT and retrospectively compared. Each plan was made using contoured structures on computed tomographic (CT) images fused with magnetic resonance imaging (MRI). The homogeneity (HI) and conformity (CI) indices of the planning target volumes (PTVs) were calculated to establish the dosimetric quality in all plans. The dose received to organs at risk (OARs), number of monitor units (MUs) and treatment time were evaluated for each type of planning technique. Results: Hybrid plans showed superior homogeneity (p = 0.04) and conformity (p = 0.01) indices compared to IMRT and VMAT plans. In terms of hippocampus sparing, the Hybrid technique showed almost equal D100% and maximum dose (Dmax) values compared to the other techniques, but without statistical significance (p> 0.05); however, there was a significant difference for the left hippocampus, where the IMRT technique obtained the best result (p <0.001). Hybrid plan values for dose delivered to the remaining OARs, MUs and treatment times were intermediate between those of IMRT and VMAT. Conclusion: Compared to the IMRT and VMAT plans, the hybrid plan showed improved dosimetric plan quality along with intermediate dose values to the OARs. [ABSTRACT FROM AUTHOR]

In this paper, we present a Monte Carlo simulation study on the charge distribution and structure of a shape- and size-asymmetric electric double layer around a spherical colloid. Specifically, the macroparticle is surrounded by a binary electrolyte composed of spherical and spherocylindrical ions, where the excluded volume of the spherocylinders is considerably larger than that of the electrolytic spheres. We have used spherocylinders of low aspect ratio (L s c / D s c = 0.5) , a sphere-spherocylinder ionic size asymmetry of D s p / D s c = 0.5 and a colloid-spherocylinder size asymmetry of D M / D s c ≈ 4.7. Results are presented for the local integrated charge and the colloid-ion radial distribution functions, considering several salt concentrations and charged states of the macroparticle. The conditions used here produce integrated charge profiles that are strongly oscillatory, with alternating layering regions of very large charge reversal and charge amplification (or overcharging), in a sequence that depends on the ionic identity of the spherocylinders. Such phenomenology is particularly visible in the regime of low colloidal charge, and it is mainly driven by the characteristics of the non-spherical ions and the size asymmetry between the ionic species. For weakly electrified macroions, the innermost region of anomalous charge has the largest amplitude and reaches absolute values of more than 15 times the native colloidal charge. [ABSTRACT FROM AUTHOR]

Background: Indocyanine green has been widely employed as a secure and easy technique for sentinel lymph node mapping in different types of cancer. Nonetheless, the usage of Indocyanine green has not been fully implemented due to the heterogeneous results found in published studies. Thus, the objective of this meta-analysis is to evaluate the overall performance of Indocyanine green for sentinel lymph node mapping and node metastasis in patients undergoing colorectal cancer surgery.Methods: An extensive systematic search was performed to identify relevant studies in English and Spanish with no time limit restrictions. For the meta-analysis, a hierarchical summary receiver operating characteristic curve (HSROCs) was constructed, and quantitative data synthesis was performed using random effects models. Specificity, sensitivity, positive, and negative likelihood ratios were obtained from the corresponding HSROC. Between-study heterogeneity was visually evaluated using Galbraith plot, and publication bias was quantified using Deeks' method.Results: A total of 11 studies were included for analysis. The pooled detection rate for sentinel lymph node mapping was 91% (80-98%). Covariates significantly influencing the pooled detection rate were having colon cancer (estimate: 1.3001; 1.114 to 1.486; p < 0.001) and the usage of a laparoscopic approach (estimate: 1.3495; 1.1029 to 1.5961; p < 0.001). The performance of Indocyanine green for the detection of metastatic lymph nodes yielded an area under the roc curve of 66.5%, sensitivity of 64.3% (51-76%), and specificity of 65% (36-85%).Conclusions: Indocyanine green for the detection of sentinel lymph node mapping demonstrates better accuracy when used in colonic cancer and by a laparoscopic approach. Nevertheless, its overall performance for the detection of lymph node metastasis is poor. [ABSTRACT FROM AUTHOR]

The hypernetted-chain/mean spherical approximation (HNC/MSA) is employed to calculate the thermodynamic properties of the restricted primitive model (symmetric binary mixture of charged hard spheres) in the low density–high coupling region, where the gas–liquid phase transition is located. The spinodal curve is calculated from the virial and the compressibility equations. The HNC/MSA total correlation function does not show long-range behavior as the spinodal curve is approached. This is due to the hybrid nature of this approximation. However, a consistent HNC/MSA total correlation function is defined which does show the expected long-range behavior. This long-range behavior is found to be related to the phenomenon of ionic clustering, in accordance with previous studies. [ABSTRACT FROM AUTHOR]

Transparent Al-doped ZnO thin films have been prepared by rf magnetron sputtering using on glass and a flexible cellulose triacetate substrates. The morphological, structural, chemical, optical and electrical properties were characterized by scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, ultra violet-visible spectroscopy (UV-Vis) and the Van der Pauw techniques respectively. The morphological analysis showed that the samples deposited on both substrates presented densely compacted grains with regular shapes, with roughness values of ~30 nm. The hexagonal wurtzite structure was obtained in both types of substrates with a preferred orientation (002), crystallite sizes of ~20 nm and with positive induced stress in the unit cell. The chemical analysis revealed the presence of Zn, O and Al atoms. Transmittance values of ∼80%, with an optical bandgap of ~3.50 eV, were obtained. The resistivity in both types of films was in the range ~10−10 Ω-cm with a mobility of ~3.6 cmVs and a carrier concentration of ~10 cm. [ABSTRACT FROM AUTHOR]

Using the hypernetted-chain/mean spherical approximation (HNC/MSA) integral equations we study the electrical double layer inside and outside a model charged cylindrical vesicle (nanopore) immersed into a primitive model macroions solution, so that the macroions are only present outside the nanopore, i.e., the vesicle wall is impermeable only to the external macroions. We calculate the ionic and local linear charge density profiles inside and outside the vesicle, and find that the correlation between the inside and outside ionic distributions causes the phenomena of overcharging (also referred to as surface charge amplification) and/or charge reversal. This is the first time overcharging is predicted in an electrical double layer of cylindrical geometry. We also report the new phenomenon of double overcharging. The present results can be of consequence for relevant systems in physical-chemistry, energy storage and biology, e.g., nanofilters, capacitors and cell membranes. [ABSTRACT FROM AUTHOR]

ZnO thin films were deposited on ITO/glass substrates by pulsed laser deposition (PLD) using two different kinds of targets. One of the targets was made of pure ZnO powder and the other one consisted of a mixture of ZnO powder with cyanoacrylate glue. The structural and morphological properties of the films obtained using both targets were compared, in order to determine which one produces samples with properties more suitable for their use as buffer and antireflective layer in CdTe-based solar cells, also different heterostructures were deposited to study the optical properties of the obtained thin films and their utility in the applications mentioned before. The films deposited with the mixture powder target were polycrystalline with preferential orientations in the planes (100) and (101) with a high transmittance in the range of 70-90% in the 540-850 nm wavelength region and showed a high resistivity of ~1.30 × 102 &#937 cm-1 , such properties are considered to be appropriate for thin films that are wanted to be used as a buffer and antireflective layer in CdTe solar cells. [ABSTRACT FROM AUTHOR]

Understanding the genetic composition and population structure of plant species at a molecular level is essential for the development of adequate strategies aimed at enhancing the conservation and use of their genetic resources. In addition, such knowledge can help to plan ahead for a scenario under which wild and cultivated species come into contact with their genetically modified (GM) counterpart(s). Using ten simple sequence repeat markers, we genotyped 409 samples pertaining to the species in the Manihot genus known to occur in Colombia, i.e. cassava (Manihot esculenta) and its wild relatives Manihot brachyloba, Manihot carthaginensis and Manihot tristis. High genetic variation was observed in all the species (HE = 0.212-0.603), with cassava showing highest diversity. Most of the genetic variation was found within species populations. Our results suggest that outcrossing events among populations occur much more frequently in M. tristis and M. esculenta, and particularly so in the latter, where the exchange of varieties among local farmers plays a key role in maintaining and introducing new genetic diversity. The occurrence of gene flow within and among populations of Manihot species in Colombia becomes relevant in a biosafety context, where gene flow from GM cassava, if introduced to the country, might have detrimental effects on the structure and dynamics of populations of wild species. The baseline information on the genetic diversity and structure of the four Colombian species that we have presented here provides a first and indispensable step towards the development of targeted interventions necessary to preserve their genetic resources. [ABSTRACT FROM AUTHOR]

Abstract: For many decades, the Gouy–Chapman model, whose cornerstone is the Poisson–Boltzmann equation, has been the traditional approach to describing the electric double layer (EDL). Since the early 1980s, a great amount of theoretical work (mostly computer simulations and integral equation theories) has proved that this classical picture of the EDL presents severe failures in the case of electrolytes with multivalent ions, as a result of neglecting ion size correlations. The overlooking of the phenomenon of charge reversal is probably one of the most representative examples of such deficiencies. This work is a critical survey on the relevance of ion size correlations in real colloidal systems (focused mainly on solutions with multivalent counterions). A sophisticated electrophoresis theory (in which ionic steric correlations are taken into account) will be applied to analyze experimental data, which will be also compared with predictions of the classical approach. In addition, we will discuss to what extent ion size correlations contribute to charge reversal in colloids of biological nature and other real colloids. Unlike the classical Poisson–Boltzmann approach, the presented theory describes the charge inversion that occurs within aqueous latexes when increasing the trivalent aqueous electrolyte concentration well above the mmolar range. [Copyright &y& Elsevier]

In this work a virtual instrument was developed, of easy understanding, which allows the monitoring of the temperature with sensor integrated type. The objective is to obtain the heat of vaporization of the work substances automatically and to present the curves of heating of the same ones; also, it was carried out a control system to maintain constant the temperature. The program was developed in the language of graphic programming LabVIEW to facilitate the analysis, the treatment of the data and the data acquisition was made with the card USB6008 of National Instruments. In this article is included a description of the combined hardware and software of the control, the measures and the prosecution of the data of the developed system. [ABSTRACT FROM AUTHOR]

The Poisson–Boltzmann (PB) and modified Poisson–Boltzmann (MPB) theories are used to investigate the primitive model of ionic fluids in the low density–large coupling regime where the liquid–vapor transition is situated. The PB and MPB spinodal curves for the restricted primitive model are calculated from the virial route and compared with those from the mean spherical approximation (energy route) and the hybrid hypernetted-chain/mean spherical approximation (virial route). The effect of unequal ion sizes on the critical point and spinodal curves is also considered. [ABSTRACT FROM AUTHOR]

There are different standard procedures to measure 131I concentration in water samples. For environmental monitoring purposes the best radiochemical procedure is the one that optimizes the following criteria: (a) lowest detection limit; (b) quickest preparation time; (c) lowest cost of preparation; and (d) does not involve hazardous chemicals. Iodine can easily form simple compounds or bind to complex organic molecules, which can be problematic for obtaining precise activity measurements from radiochemical procedures. In this study, a comparative analysis of three different iodine determination techniques was performed to determine the most time and cost effective technique for environmental monitoring purposes. [ABSTRACT FROM AUTHOR]

At present, the research community recognises a complementary relationship between the semantic and the social web. The merging of these web instances could play an essential role in different knowledge domains. In this study, the authors promote a social-semantic web paradigm using software engineering as the knowledge domain specifically. The authors address a major problem - the difficulty for end-users in finding documentation related to software requirements proposed by them; this fact reduces their participation at the time of specifying the software requirements. Architecture is proposed for enhanced resources search, combining the strengths of the social (social annotations) and semantic (semantic metadata) technologies, which has been designed considering the search style of the information seekers. Such architecture is applied in a use-scenario, where the expert users who are not technicians have some restrictions and limitations to retrieve the documents they need. The preliminary results demonstrate that it is possible to take advantage of the defined infrastructure of the ontology to organise and integrate the metadata of resources which are in databases or existent files; this approach opens several possibilities as creation and validation of software requirements collaboratively among different expert-users. [ABSTRACT FROM AUTHOR]

Virtual tools were built to be used as educational support in the basic teaching of the thermodynamics in engineering degree of the Universidad de America. The programs have an excellent human machine interface that facilitates their use a lot on the part of inexpert students in the area and were designed by students of advanced courses of the Engineering. The impact of these tools was measured in a course of 25 students with obtaining excellent results. [ABSTRACT FROM AUTHOR]

A diversity survey was used to estimate allelic diversity and heterozygosity of 129 microsatellite markers in a panel of 44 common bean ( Phaseolus vulgaris L.) genotypes that have been used as parents of mapping populations. Two types of microsatellites were evaluated, based respectively on gene coding and genomic sequences. Genetic diversity was evaluated by estimating the polymorphism information content (PIC), as well as the distribution and range of alleles sizes. Gene-based microsatellites proved to be less polymorphic than genomic microsatellites in terms of both number of alleles (6.0 vs. 9.2) and PIC values (0.446 vs. 0.594) while greater size differences between the largest and the smallest allele were observed for the genomic microsatellites than for the gene-based microsatellites (31.4 vs. 19.1 bp). Markers that showed a high number of alleles were identified with a maximum of 28 alleles for the marker BMd1. The microsatellites were useful for distinguishing Andean and Mesoamerican genotypes, for uncovering the races within each genepool and for separating wild accessions from cultivars. Greater polymorphism and race structure was found within the Andean gene pool than within the Mesoamerican gene pool and polymorphism rate between genotypes was consistent with genepool and race identity. Comparisons between Andean genotypes had higher polymorphism (53.0%) on average than comparisons among Mesoamerican genotypes (33.4%). Within the Mesoamerican parental combinations, the intra-racial combinations between Mesoamerica and Durango or Jalisco race genotypes showed higher average rates of polymorphism (37.5%) than the within-race combinations between Mesoamerica race genotypes (31.7%). In multiple correspondance analysis we found two principal clusters of genotypes corresponding to the Mesoamerican and Andean gene pools and subgroups representing specific races especially for the Nueva Granada and Peru races of the Andean gene pool. Intra population diversity was higher within the Andean genepool than within the Mesoamerican genepool and this pattern was observed for both gene-based and genomic microsatellites. Furthermore, intra-population diversity within the Andean races (0.356 on average) was higher than within the Mesoamerican races (0.302). Within the Andean gene pool, race Peru had higher diversity compared to race Nueva Granada, while within the Mesoamerican gene pool, the races Durango, Guatemala and Jalisco had comparable levels of diversity which were below that of race Mesoamerica. [ABSTRACT FROM AUTHOR]

Reports on the molecular structure of substituted phenylamine benzoquinone derivatives synthesis and correlation of spectroscopic, electrochemical and theoretical parameters. Effect of a hydrogen bon between the alpha-hydroxy and carbonyl groups; Measurement of reduction potentials of compounds using cyclic voltammetry in anhydrous acetonitrile; Typical behavior of quinones, with or without alpha-phenotic protons.