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Clinical and demographic features of patients undergoing videocapsule endoscopy management:A descriptive study

World Journal of Gastrointestinal Endoscopy 2024年第7期16卷 424-431页

作者： María C Mejía Luis G Piñeros Luis M Pombo Laura A León Jenny A Velásquez Aníbal A Teherán Karen P Ayala Research Center Fundación Universitaria Juan N.CorpasBogotá111321Colombia Fundación Universitaria Juan N.Corpas Bogotá111321Colombia Department of Gastroenterology Universidad Militar Nueva GranadaBogotá111711Colombia Department of Gastroenterology Hospital Universitario Clínica San RafaelBogotá111711Colombia

BACKGROUND Video-capsule endoscopy(VCE)is an efficient tool that has proven to be highly useful in approaching several gastrointestinal *** was implemented in Colombia in 2003,however current characterization of patients undergoing VCE in Colombia is limited,and mainly comes from two investigations conducted before the SARS-CoV-2 pandemic *** To describe the characteristics of patients undergoing VCEs and establish the main indications,findings,technical limitations,and other outstanding *** A descriptive study was carried out using data from reports of VCE(PillCam SB3 system)use in a Gastroenterology Unit in Bogotá,Colombia between September 2019 and January *** and clinical variables such as indication for the VCE,gastric and small bowel transit times(GTT,SBTT),endoscopic preparation quality,and limitations were described[n(%),median(IQR)].RESULTS A total of 133 VCE reports were *** were in men with a median age of 70 *** majority had good preparation(96.2%),and there were technical limitations in 15.8%of *** main indications were unexplained anemia(91%)or occult bleeding(23.3%).The median GTT and SBTT were 14 and 30 minutes,*** frequencies of bleeding stigma(3.79%)and active bleeding(9.09%)were low,and the most frequent abnormal findings were red spots(28.3%),erosions(17.6%),and vascular ectasias(12.5%).CONCLUSION VCE showed high-level *** main indication was unexplained *** bleeding was the most frequent *** with artificial intelligence,VCE can improve diagnostic precision and targeted therapeutic interventions.

关键词： Endoscopy Video-capsule endoscopy Capsule endoscopy Gastrointestinal diseases Observational study Gastrointestinal bleeding

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Prediction of environment variables in precision agriculture using a sparse model as data fusion strategy

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Information Processing in Agriculture 2022年第2期9卷 171-183页

作者： L.Mancipe-Castro R.E.Gutierrez-Carvajal Multimedia Engineering Program/universidad Militar nueva granada Bogota 110111Colombia

Precision agriculture seeks to optimize production processes by monitoring and analyzingenvironmental variables. For example, establishing farming actions on the crop requiresanalyzing variables such as temperature, ambient humidity, soil moisture, solar irradiance,and Rainfall. Although these signals might contain valuable information, it is vital to mixup the monitored signals and analyze them as a whole to provide more accurate information than analyzing the signals separately. Unfortunately, monitoring all these variablesresults in high costs. Hence it is necessary to establish an appropriate method that allowsthe infer variables behavior without the direct measurement of all of *** paper introduces a multi-sensor data fusion technique, based on a sparse representation, to find the most straightforward and complete linear equation to predict and understand a particular variable behavior based on other monitored environmental variablesmeasurements. Moreover, this approach aims to provide an interpretable model that allowsunderstanding how these variables are combined to achieve such results. The fusion strategy explained in this manuscript follows a four-step process that includes 1. data cleaning,2. redundant variable detection, 3. dictionary generation, and 4. sparse regression. Thealgorithm requires a target variable and two highly correlated signals. It is essential to pointout that the developed method has no restrictions to specific variables. Consequently, it ispossible to replicate this method for the semiautomatic prediction of multiple critical environmental *** a case study, this work used the SML2010 data set of the UCI machine learning repository to predicted the humidity’s derivative trend function with an error rate lower than 17%and a mean absolute error lower than 6%. The experiment results show that even thoughsparse model predictions might not be the most accurate compared to those of linearregression (LR), support vector m

关键词： Precision agriculture Multi-sensor data fusion Sparse representation Inference of variables Humidity

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Vinyl sulfonyl chemistry-driven unidirectional transport of a macrocycle through a[2]rotaxane

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Organic Chemistry Frontiers 2022年第3期9卷 633-642页

作者： Arthur H.G.David Pablo García-Cerezo Araceli G.Campaña Francisco Santoyo-González Victor Blanco Departamento de Química Orgánica Facultad de CienciasUnidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente(UEQ)Universidad de Granada(UGR)Avda.Fuente Nueva S/N18071 GranadaSpain

By applying a combination of the coupling-and-decoupling(CAD)chemistry of the vinyl sulfonate group with the click thia-Michael addition to the vinyl sulfone group(MAVS)we performed the irreversible unidirectional transportation of the ring through the linear component in a[2]rotaxane by a chemically and pHdriven flashing energy ratchet mechanism.

关键词： mechanism unidirectional chemistry

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Parabolic Trough Collector and Central Receiver Coupled with Fresnel Lens:Experimental Tests

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International Journal of Automation and computing 2020年第4期17卷 572-587页

作者： Angelica Palacios Dario Amaya Olga Ramos universidad Militar nueva granada Bogota 110121Colombia

Renewable energies have a high impact on power energy production and reduction of environmental pollution worldwide,so high efforts have been made to improve renewable technologies and research about *** paper presents the thermal performance results obtained by simulation and experimental tests of a parabolic trough collector with central receiver coupled to Fresnel lens,under different configurations on the *** simulation method was computational fluid dynamics(CFD)analysis in SolidWorks(R)soft-ware tool,which works with Naiver-Stokes equations to converge on a *** tests were formed with all configurations proposed and three observations for each one,a total of 12 observations were performed in all *** a result,the best thermal performance in simulation was achieved with the Fresnel lens and black pipe collector,with a maximum temperature of 116℃under 1000 W/m^2 radiation,the same system achieved in experimental tests a maximum temperature of 96℃with a radiation of 983 W/m^2.

关键词： Solar collector parabolic trough collector Fresnel lens thermal conductivity solar power

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A theory of very short-time price change:security price drivers in times of high-frequency trading

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Financial Innovation 2022年第1期8卷 1800-1833页

作者： Gianluca P.M.Virgilio universidad Católica Sedes Sapientiae Nueva CajamarcaPeru

Academic research has identified several factors that affect price movements;however,the scenario changes abruptly in the case of very short time price changes(VSTPC).This topic is not specifically examined in the existing literature;nonetheless,the behavior of the market microstructure is quite different at the subsecond ***,below a certain psychological time threshold,most factors typically influencing price changes cease to *** paper analyzes several parameters considered to affect price changes and identifies four of them as potentially influencing *** factors are previous volatility,scarce liquidity,high quantity exchanged,and stop-loss(SL)orders(seldom mentioned in the literature).These four parameters are examined by means of a mathematical model,audit trail data analysis,Granger-causality testing,and agent-based *** results of these four techniques converge to suggest a nonlinear combination of previous volatility,liquidity,and SL orders as the main causes of excess ***,contrary to mainstream literature on trading time above a certain psychological threshold,the volumes exchanged are not integral agents for ***,financial markets face many ultrafast orders,yet a coherent theory of price change at time scales incomprehensible by humans and only manageable by computers is still *** theory presented in this paper attempts to fill this *** outcome of such a theory is important for purposes of market stability,crisis avoidance,investment planning,risk management,and high-frequency trading.

关键词： High-frequency trading Subsecond time scale Volatility Liquidity Exchange volume Stop-loss orders

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Receiver tube heat transfer analysis of a CCP collector designed based on branched fractals geometry

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International Journal of Agricultural and Biological Engineering 2020年第5期13卷 56-62页

作者： Angélica Palacios Darío Amaya Olga Ramos GAV Research Group Universidad Militar Nueva GranadaBogota 110111Colombia

For the development of systems related to renewable energy and specifically for thermo-solar energy,it is essential to study and analyze the different thermal phenomena of heat transfer,in search of the best conditions that allow strengthening the *** such as radiation,convection,and conduction are highly studied,from the field of materials to the field of infrastructure,finding day to day optimal solutions that guarantee a great use of the solar resource available on the earth's *** study presented the results of heat transfer analysis on a receiver pipe in a CCP;designed using the theory of branched fractal geometry to improve the heat transfer associated with concentrating solar capture systems.A fractal structure as a branch or arboreal fractal type network,influenced thermal and electrical parameters,as electrical resistance,thermal resistance,and convective heat transfer,so increasing the level branch heat transfer can be enhancement along of the *** use of renewable energies in agriculture benefits the industrial processes that require a continuous power system,due to climatic conditions and geographical location is not a guarantee in food production fields,which reason solar capture systems contribute to food dehydration processes,water heating,refrigeration,and energy production.

关键词： heat transfer fractal geometry solar collector fractality fractal dimension parabolic cylindrical concentrator

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Particulate matter geochemistry of a highly industrialized region in the Caribbean:Basis for future toxicological studies

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Geoscience Frontiers 2022年第1期13卷 376-387页

作者： Luis F.O.Silva Ismael L.Schneider Paulo Artaxo Yuleisy Núñez-Blanco Diana Pinto Érico M.M.Flores Leandro Gómez-Plata Omar Ramírez Guilherme L.Dotto Department of Civil and Environmental Universidad de la CostaCUCCalle 58#55–66BarranquillaAtlánticoColombia Department of Applied Physics Institute of PhysicsUniversity of São PauloBrazil Department of Chemistry Universidade Federal de Santa MariaRSBrazil universidad Militar nueva granada(UMNG) Faculty of EngineeringEnvironmental EngineeringKm 2 Cajicá-ZipaquiráColombia Chemical Engineering Department Federal University of Santa Maria-UFSM1000Roraima Avenue97105-900 Santa MariaRSBrazil

Air pollution has become an important issue,especially in Caribbean urban areas,and,particulate matter(PM)emitted by different natural and anthropogenic sources causes environmental and health *** this work,we studied the concentrations of PM_(10) and PM_(2.5) sources in an industrial and port urban area in the Caribbean region of *** samples were collected within 48-h periods between April and October 2018 by using a Partisol 2000 i-D *** geochemical characterization was performed by X-ray fluorescence(XRF)***,ionic species and black carbon(BC)were quantified by ion chromatography and reflectance spectroscopy,*** the Positive Matrix Factorization(PMF)receptor model,the contributions of PM sources were *** average concentration of PM_(10) was 46.6±16.2μg/m^(3),with high concentrations of Cl and *** PM_(2.5),the average concentration was 12.0±3.2μg/m^(3),and the most abundant components were BC,S,and *** receptor model identified five sources for PM_(10) and PM_(2.5).For both fractions,the contributions of marine sea spray,re-suspended soil,and vehicular traffic were *** addition,PM_(2.5) included two mixed sources were found to be fuel oil combustion with fertilizer industry emissions,and secondary aerosol sources with building construction ***,PM_(10) was found to also include building construction emissions with re-suspended soil,and metallurgical industry *** obtained geochemical atmospheric results are important for the implementation of strategies for the continuous improvement of the air quality of the Caribbean region.

关键词： Urban air pollution Particulate matter Geochemical composition Aerosol source apportionment Receptor models PMF

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Gastrointestinal tuberculosis:An autopsy-based study

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Infectious Medicine 2023年第2期2卷 122-127页

作者： Julio Cesar Mantilla Juan JoséChaves Ferney Africano-Lopez Néstor Blanco-Barrera Marta Juliana Mantilla Department of Pathology Universidad Industrial de SantanderBucaramanga 680002Colombia Department of Pathology Hospital Universitario de SantanderBucaramanga 680002Colombia Department of Pathology Fundación Universitaria de Ciencias de la SaludBogotá111411Colombia Department of Gastroenterology Gastrocenter and Medical SpecialitiesIpiales 524061Colombia Department of Gastroenterology Universidad Militar Nueva GranadaBogotá250240Colombia Department of Rheumatology Universidad de la SabanaChía 250001Colombia

Background:Tuberculosis is a disease of great relevance since it is one of the leading causes of morbidity and mortality *** tuberculosis is an unusual *** is defined as the involvement of any segment of the digestive tract,associated viscera,and *** study’s main objective is to collect information from autopsies of patients diagnosed with gastrointestinal tuberculosis in a Pathology reference center in ***:This is a retrospective and descriptive study of autopsy reports.A total of 4,500 autopsies were performed between January 2004 and December *** inclusion criteria were authorization of a family member following local law regulations and a final autopsy diagnosis of gastrointestinal tuberculosis using microscopic ***:Forty-eight patients with gastrointestinal tuberculosis autopsies were included in our *** of the patients were male(n=35,72.9%)with a median age of 40.5 years *** immunodeficiency virus infection history was reported in 28 cases(58.33%).The most affected gastrointestinal tract site was the terminal *** and thickened epithelium were common autopsies macroscopic *** multiorgan compromise was a relevant finding in patients with gastrointestinal ***:Gastrointestinal tuberculosis is a disease of great importance,being its diagnosis a clinical *** can be reported in a high percentage of cases,so autopsy diagnosis can help reveal more accurate data about this condition.

关键词： Gastrointestinal tuberculosis Autopsy Forensic pathology Infections Colombia

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Completion thyroidectomy:is timing important for transcervical and remote access approaches?

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World Journal of Otorhinolaryngology-Head and Neck Surgery 2020年第3期6卷 165-170页

作者： Juan Pablo Duenas Carlos Simon Duque Laura Cristancho Manuela Mendez Hospital Pablo Tobon Uribe Instituto de Cancerologia IDC Las AmericasClfnica Universitaria BolivarianaClinica el Rosario Sede el Tesoro(CLID)MedellinColombia universidad militor nueva granada BogotaDCColombia universidad CES MedellinColombia Hospital Pablo Tobon Uribe Clfnica Las AmericasMedellinColombia

Completion thyroidectomy(CT)is employed after lobectomy when histopathological results mandates total removal of the gland as in case of well differentiated thyroid carcinoma(DTC).It is also employed as a second stage thyroid surgery when unfavorable events occur as in recurrent laryngeal nerve injury or when the surgeon finds out the case is beyond his/her expertise in an attempt to protect the contralateral side and allowing time for recovery or for an expert surgeon to help.

关键词： Completion thyroidectomy Total thyroidectomy Complications Nerve monitoring

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Improved shape hardening function for bounding surface model for cohesive soils

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Journal of Rock Mechanics and Geotechnical Engineering 2014年第4期6卷 328-337页

作者： Andrés Nieto-Leal Victor N.Kaliakin Department of Civil & Environmental Engineering University of Delaware Newark DE 19716 USA Department of Civil Engineering Universidad Militar Nueva Granada Bogotá Colombia

A shape hardening function is developed that improves the predictive capabilities of the generalized bounding surface model for cohesive soils, especially when applied to overconsolidated specimens. This improvement is realized without any changes to the simple elliptical shape of the bounding surface, and actually reduces the number of parameters associated with the model by one.

关键词： Constitutive model Bounding surface plasticity Shape hardening function Clay

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