Multi-objective evolutionary optimization for dimensionality reduction of texts represented by synsets.

Despite new developments in machine learning classification techniques, improving the accuracy of spam filtering is a difficult task due to linguistic phenomena that limit its effectiveness. In particular, we highlight polysemy, synonymy, the usage of hypernyms/hyponyms, and the presence of irrelevant/confusing words. These problems should be solved at the pre-processing stage to avoid using inconsistent information in the building of classification models. Previous studies have suggested that the use of synset-based representation strategies could be successfully used to solve synonymy and polysemy problems. Complementarily, it is possible to take advantage of hyponymy/hypernymy-based to implement dimensionality reduction strategies. These strategies could unify textual terms to model the intentions of the document without losing any information (e.g., bringing together the synsets "viagra", "ciallis", "levitra" and other representing similar drugs by using "virility drug" which is a hyponym for all of them). These feature reduction schemes are known as lossless strategies as the information is not removed but only generalised. However, in some types of text classification problems (such as spam filtering) it may not be worthwhile to keep all the information and let dimensionality reduction algorithms discard information that may be irrelevant or confusing. In this work, we are introducing the feature reduction as a multi-objective optimisation problem to be solved using a Multi-Objective Evolutionary Algorithm (MOEA). Our algorithm allows, with minor modifications, to implement lossless (using only semantic-based synset grouping), low-loss (discarding irrelevant information and using semantic-based synset grouping) or lossy (discarding only irrelevant information) strategies. The contribution of this study is two-fold: (i) to introduce different dimensionality reduction methods (lossless, low-loss and lossy) as an optimization problem that can be solved using MOEA and (ii) to provide an experimental comparison of lossless and low-loss schemes for text representation. The results obtained support the usefulness of the low-loss method to improve the efficiency of classifiers.

Bromelain-based enzymatic burn debridement: Spanish multidisciplinary consensus.

Background: Bromelain-based enzymatic debridement is gaining increased interest from burn specialists in the last few years. The objective of this manuscript is to update the previous, first Spanish consensus document from 2017 (Martínez-Méndez et al. 43:193-202, 2017), on the use of enzymatic debridement with NexoBrid® in burn injuries, adding the clinical experience of a larger panel of experts, integrating plastic surgeons, intensivists, and anesthesiologists. Methods: A consensus guideline was established by following a modified Delphi methodology of a 38-topic survey in two rounds of participation. Items were grouped in six domains: general indication, indication in critical patients, pain management, conditions for NexoBrid® application, NexoBrid® application technique, and post-debridement wound care. Results: In the first round, experts established consensus (strongly agree or agree) on 13 of the 38 statements. After the second round, a consensus was reached on 24 of the 25 remaining statements (97.2%). Conclusions: The present updated consensus document provides recommendations on the use of bromelain-based enzymatic debridement NexoBrid®, integrating the extensive clinical experience of plastic surgeons, intensivists, and anesthesiologists in Spain. Further clinical trials and studies are required to corroborate, modify, or fine tune the current statements.

Photochemical and electrochemical reduction of graphene oxide thin films: tuning the nature of surface defects.

Individual and combined photo(electro)chemical reduction treatments of graphene oxide thin films have been performed to modulate the type of defects introduced into the graphene sheets during the reduction. These were characterized by X-ray photoelectron and Raman spectroscopies, nuclear reaction analysis and electrochemical methods. Illumination of the graphene oxide thin film electrodes with low irradiance simulated solar light provoked the photoassisted reduction of the material with negligible photothermal effects. The photoreduced graphene oxide displayed a fragmented sp2 network due to the formation of a high density of defects (carbon vacancies) and the selective removal of epoxides and hydroxyl groups. In contrast, the electrochemical reduction under mild polarization conditions favored the formation of sp3 defects over vacancies, with a preferential removal of carbonyl and carboxyl groups over hydroxyl/epoxides. Used in conjunction, mild photochemical and electrochemical treatments allowed the obtainment of reduced graphene oxides with varied reduction degrees (ca. C/O ratio ranging from 4.9 to 2.2), and surface defects. Furthermore, the electrochemical reduction prevented the formation of vacancies during the subsequent illumination step. In contrast, both types of defects were accumulated when the GO electrode was first exposed to illumination and then polarized.

Synergistic effect of zeolite/chitosan in the removal of fluoride from aqueous solution.

Today, fluoride represents one of the most often found, and resilient, pollutants threatening the health of millions of people around the globe. The use of biosorbents is an interesting alternative technique for the removal of fluorine-ions. Chitosan is a natural biopolymer with surface groups capable of removing fluorine; however, their lack of mechanical stability restricts its application. In the present work, we proposed that such limitations can be overcame by forming a composite with zeolite (ZCC). A proper zeolite-to-chitosan ration must be kept to prevent a collapse of the material's capacity. Two ZCCs at ratios of 1:1 and 1:3 were formed and tested for the removal of fluoride from aqueous solution. The composites were characterized by Electron Microscopy, FT-IR, N2 physisorption, and potentiometric titration techniques. During fluoride adsorption studies, the effects of pH and temperature were analysed and thermodynamic parameters for adsorption were calculated. The results demonstrated that there is a chemical interaction between the zeolite and chitosan components leading to a superior adsorption performance than if there was a simple physical mixture of the precursors. Maximum adsorption capacities were reached using the composite material with the lowest chitosan content due to reduced constriction of the zeolite pores and a better dispersion of overall the adsorption sites. Both pH and temperature had a significant, and negative, impact on the adsorption; these effects were discussed. The present work represents an advance in the development of functional biocomposites for the removal of pollutants from aqueous solutions.

A multiple classifier system identifies novel cannabinoid CB2 receptor ligands.

Drugs have become an essential part of our lives due to their ability to improve people's health and quality of life. However, for many diseases, approved drugs are not yet available or existing drugs have undesirable side effects, making the pharmaceutical industry strive to discover new drugs and active compounds. The development of drugs is an expensive process, which typically starts with the detection of candidate molecules (screening) after a protein target has been identified. To this end, the use of high-performance screening techniques has become a critical issue in order to palliate the high costs. Therefore, the popularity of computer-based screening (often called virtual screening or in silico screening) has rapidly increased during the last decade. A wide variety of Machine Learning (ML) techniques has been used in conjunction with chemical structure and physicochemical properties for screening purposes including (i) simple classifiers, (ii) ensemble methods, and more recently (iii) Multiple Classifier Systems (MCS). Here, we apply an MCS for virtual screening (D2-MCS) using circular fingerprints. We applied our technique to a dataset of cannabinoid CB2 ligands obtained from the ChEMBL database. The HTS collection of Enamine (1,834,362 compounds), was virtually screened to identify 48,232 potential active molecules using D2-MCS. Identified molecules were ranked to select 21 promising novel compounds for in vitro evaluation. Experimental validation confirmed six highly active hits (> 50% displacement at 10 µM and subsequent Ki determination) and an additional five medium active hits (> 25% displacement at 10 µM). Hence, D2-MCS provided a hit rate of 29% for highly active compounds and an overall hit rate of 52%.

The adsorption kinetics of cadmium by three different types of carbon nanotubes.

Oxidized nitrogen-doped multiwall carbon nanotubes (ox-N-MWCNTs), oxidized multiwall carbon nanotubes (ox-MWCNTs), and oxidized single-wall carbon nanotubes (ox-SWCNTs) were evaluated via batch adsorption kinetic experiments to determine the effect of nanotube morphology on the adsorption rate of cadmium. The nanotubes were characterized by HRTEM, XRD and Raman spectroscopy. Cadmium adsorption isotherms were determined at pH 6. Analyses of the kinetic data with an external mass transport model and an intraparticle diffusion model considered two cases: (1) single nanotubes suspended in aqueous solution and (2) agglomerates of nanotubes suspended in aqueous solution. The intraparticle diffusion model produced the best fit to the experimental data. However, only the diffusivity coefficients for single nanotubes suspended in solution were similar to literature values: about 4×10(-9), 1×10(-9) and 2.4×10(-11) cm(2)/s for ox-N-MWCNTs, ox-MWCNTs and ox-SWCNTs, respectively. The morphology of the various carbon nanotubes might determine cadmium diffusivity. The high amount of sidewall pores observed in the single-walled carbon nanotubes could limit cadmium diffusion and account for the slow diffusion rate of 180 min. Conversely, the short length, small surface area and bamboo-type morphology observed with nitrogen-doped multiwall carbon nanotubes may account for the relatively fast adsorption rate of 15 min as this morphology prevents cadmium diffusion through the internal tubular space of these nanotubes.

Immediate breast reconstruction (IBR) with direct, anatomic, extra-projection prosthesis: 102 cases.

There are different methods described until now for immediate breast reconstruction. Despite the use of autologous flaps considered by many authors, implants are considered as an option by others. A prospective study of 102 clinical cases was designed, including a 1-year follow-up in which glands were reconstructed by immediate breast reconstruction (IBR) with direct, extra projection, anatomic prostheses located in a submuscular pocket after a skin-sparing mastectomy. The prosthesis coverage was made by the muscle in its upper two thirds and by using the skin from the mastectomy in its lower third. The cosmetic results obtained were evaluated according to the volume, form, and symmetry achieved using a linear numeric analogical score. This evaluation had an averaged value of 2.79 +/- 0.8 in our scale from poor (0) to excellent result (4). The overall rate of complications was 15.7% of the cases, with seroma being the most frequent. In conclusion, this preliminary study demonstrates that immediate breast reconstruction with a direct, extra projection, anatomic prosthesis is a good alternative. Nevertheless, more long-term studies with a higher number of patients and using an SF-36 for patient satisfaction are needed to confirm these results.

Litotricia biliar endoscópica y drenaje percutáneo endoscópico combinados en el manejo de la colangitis aguda: Primera experiencia en Panamá / Lithotripsy biliary endoscopic and percutaneous drainage endoscopic combined in the handling of the acute cholangitis: Firts experience in Panamá

Dos casos raros de colangitis aguda son estudiados. El uno tenía piedra de 3 cm. de diámetro en el colédoco, la cual fue fragmentada endoscópicamente con el lilotriptor mecánico. Al otro paciente se le había practicado una hemigastrectomía y anastomosis gastroduodenal tipo II; y después una colecistectomía. En esta ocasión, para extraerle los cálculos, hubo que efectuar el drenaje percutáneo- endoscópico y practicarle la espinterotomía

Helicobacter Pylori y patología gastroduodenal en la República de Panamá / Helicobacter Pylori and gastroduodenal pathology in the República de Panamá

Se estudió prospectivamente la infección por Helicobacter pylori en 129 panameños y norteamericanos que tenían dispepsia crónica. Se correlacionó con la patología gastroduodenal diagnosticada por endoscopía e histología. Se comparó la utilidad de la prueba rápida de la urea con el método de cultivo. La infección por H. pylori aumentó con la edad. En menores de 30 años : 37 (por ciento); de 31 a 40 años : 61 (por ciento); de 41 a 70 : 75 (por ciento). Fué más común en los panameños (70 por ciento) que en los norteamericanos (54 por ciento). Se encontró en 81 (por ciento), 75 (por ciento), 54 (por ciento) y 29 (por ciento) de pacientes con ulcera duodenal, gastritis crónica, duodenitis y en pacientes con endoscopía e histología normales, respectivamente. La prueba rápida de la urea sirvió para producir la positividad de la enfermedad en 98 (por ciento). Se discuten los resultados y se revisa la literatura