Método híbrido para categorización de texto basado en aprendizaje y reglas

En este artículo se presenta un nuevo método híbrido de categorización automática de texto, que combina un algoritmo de aprendizaje computacional, que permite construir un modelo base de clasificación sin mucho esfuerzo a partir de un corpus etiquetado, con un sistema basado en reglas en cascada que se emplea para filtrar y reordenar los resultados de dicho modelo base. El modelo puede afinarse añadiendo reglas específicas para aquellas categorías difíciles que no se han entrenado de forma satisfactoria. Se describe una implementación realizada mediante el algoritmo kNN y un lenguaje básico de reglas basado en listas de términos que aparecen en el texto a clasificar. El sistema se ha evaluado en diferentes escenarios incluyendo el corpus de noticias Reuters-21578 para comparación con otros enfoques, y los modelos IPTC y EUROVOC. Los resultados demuestran que el sistema obtiene una precisión y cobertura comparables con las de los mejores métodos del estado del arte

Glutathione S-Transferase T1 Null Genotype is Associated with Susceptibility to Inflammatory Bowel Disease

Background: The published literature contains conflicting results regarding the impact of the glutathione S-transferase T1 (GSTT1) null genotype on the susceptibility to inflammatory bowel disease. Therefore, we conducted a meta-analysis of observational studies to assess the association. Methods: We searched four online databases for eligible studies. The odds ratio (OR) with 95% CI was used to assess the gene-disease association. We also performed subgroup analyses by type of inflammatory bowel disease and ethnicity. Results: There were 16 individual studies from 11 publications included in the analysis. There were 3366 cases with inflammatory bowel disease and 6013 controls. The meta-analysis of all 16 studies showed the GSTT1 null genotype was associated with increased susceptibility to inflammatory bowel disease (OR = 1.98, 95%CI 1.39-2.84, P < 0.001). The subgroup analysis by ethnicity further identified an association between the GSTT1 null genotype and inflammatory bowel disease in Caucasians, Asians, and Africans. The GSTT1 null genotype was associated with both ulcerative colitis (OR = 1.96, P = 0.004) and Crohn’s disease (OR = 2.01, P = 0.022). The GSTT1 null genotype was still significantly associated with ulcerative colitis (OR = 1.63, P < 0.0001) and Crohn’s disease (OR = 1.40, P = 0.023) after adjusting for study heterogeneity. Conclusion: The GSTT1 null genotype is significantly associated with an increased susceptibility to inflammatory bowel disease and is a risk factor for both ulcerative colitis and Crohn’s disease

Preparation of nano-sized calcium carbonate in solution mixing process

Discreet nano-sized precipitated calcium carbonate was prepared by a simple solution mixing process, in which sodium carbonate solution was injected into calcium chloride solution containing calcium hydroxide. The morphology, size, and structure of the as-prepared precipitated calcium carbonate and intermediate products were examined. The results indicated that the non-impurity additive of calcium hydroxide, temperature below 30 degrees C, and controlled injecting rate were essential to obtain nano-sized precipitated calcium carbonate in the solution mixing process. It was observed that the intermediate nanofibrils fragged into nanograins in the process. This method can provide a simpler method to study the formation mechanism of nano calcium carbonate

Simultaneous measurement of ionizing radiation and heart rate using a smartphone camera

Complementary metal oxide semiconductor (CMOS) cameras have been used to detect ionizing radiation when shaded from light or under the condition of static scenes. We propose a novel idea for simultaneous measurement of ionizing radiation and heart rate (HR) by using a smartphone with its CMOS camera lens covered by a finger in one measurement. Verified experiments were conducted: videos were recorded using a Xiaomi8 smartphone when the camera lens was covered by a finger and a light-tight tape for controlled experiment, with a ∼33 mCi 99mTc liquid radioactive source at six different distances (from 20 to 70 cm, step size 10 cm) from the camera. The exact HRs were measured using an oximeter at the same time. Image processing algorithm is proposed to extract radiation events and HR in the same videos. Results show that: (1) frame numbers containing radiation-related bright spots in two experiments have a linear relationship, and they are inversely proportional to the square of the distance between the camera and radiation source; (2) the HR difference between the video processing and the oximeter result is less than 2 beats per minute. In conclusion, it verifies that the proposed method is available to detect ionizing radiation and measure HR simultaneously with smartphone camera lens covered by a finger. We have been working on the development of an Android phone application based on the algorithms

Co-adsorption characteristics of antibiotics with different functional groups and cadmium combined contamination on activated carbon

International audienceDue to the diversity of functional groups of antibiotics, antibiotics are easy to complex with metals, thereby changing their migration and transformation behavior. The adsorption/complexation mechanism of three antibiotics co-adsorbed with Cd(Ⅱ) and systematic comparison were studied using Raman, FTIR, XPS and Materials Studio (norfloxacin (NOR), sulfamethazine (SMT) and tetracycline (TC)). We concluded that two NORs complexed with Cd(Ⅱ) through oxygen atoms from carboxylic acid and carbonyl in ketone group to form a six-membered ring chelate. The Cd(II)(NOR±)2+ showed a stronger adsorption coefficient than other forms of NOR, Cd(II)(NOR±)2+, NOR and Cd(Ⅱ) would compete the same permanent charge sites, thus exhibiting an inhibitory effect on NOR adsorption. Contrarily, one SMT molecule complexed with Cd(Ⅱ) through the N atom on pyrimidine ring and the -NH attached to the pyrimidine ring, forming an AC-Cd(Ⅱ)-SMT ternary complex on activated carbon (AC), and Cd(Ⅱ) acted as bridge. The bridging effect of Cd(Ⅱ) and multi-layer adsorption of SMT provided more adsorption sites for SMT, thus promoting the SMT adsorption. There was no complexation between TC and Cd(Ⅱ), and the addition of Cd(Ⅱ) had no significant effect on TC adsorption. The adsorption capacity of AC-Cd(Ⅱ)-SMT complex (107.4 mg·g−1) was stronger than NOR-Cd(Ⅱ) complex (40.2 mg·g−1), and the adsorption capacity of antibiotics was SMT>TC>NOR in all systems. The correlation analysis and molecular orbital calculation further supported the strong effect of complexation between Cd(Ⅱ) and antibiotics with different function groups on the adsorption, and the environmental behavior of system was jointly determined by complex structure and adsorption mechanism

Synthesis of high-performance La_0.6Sr_0.4CoO_3−δ nano-powder prepared via an acetic-acrylic method

A novel acetic-acrylic (AA) approach was developed to obtain La0.6Sr0.4CoO3−δ (LSC) using lanthanum oxide, acetate, and acrylic acid as the starting materials. We synthesized several LSC products with varying acrylic acid (L) and metal salt (M) molar ratios (L/M). The precursors and the final products were thoroughly characterized. When the L/M molar ratio is 0.9, the high-purity nano LSC powders were obtained by heating at 900 °C. The conductivity of LSC bulk sample was equal to 2534 and 2430 S cm−1 at 650 and 700 °C, respectively. This sintered LSC was used in a cathode with polarisation resistances (Rp) of 0.190 and 0.084 Ω·cm2 at 650 and 700 °C, respectively. It was observed that at 700 and 650 °C, the power density of an anode with a structure that might be defined as Ni-3YSZ/8YSZ/GDC/LSC-0.9 was 947 and 585 mW cm−2, respectively. Our results revealed that the high-performance LSC powders could be synthesized by the acetic-acrylic synthesis method, applicable to a large scale