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1.
Energy Fuels ; 38(17): 16473-16489, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39257465

RESUMO

Bio-oils contain a substantial number of highly oxygenated hydrocarbons, which often exhibit low thermal stability during storage, handling, and refining. The primary objectives of this study are to characterize the hydroxyl group in bio-oil fractions and to investigate the relationship between the type of hydroxyl group and accelerated aging behavior. A bio-oil was fractionated into five solubility-based fractions, classified in two main groups: water-soluble and water-insoluble fractions. These fractions were then subjected to chemoselective reactions to tag molecules containing hydroxyl groups and analyzed by negative-ion electrospray ionization 21 T Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The fractions were also subjected to accelerated aging experiments and characterized by FT-ICR MS and bulk viscosity measurements. Extracting insightful information from ultrahigh-resolution data to aid in predicting upgrading methodologies and instability behaviors of bio-oils is challenging due to the complexity of the data. To address this, an unsupervised learning technique, k-means clustering analysis, was used to semiquantify molecular compositions with a close Euclidean distance within the (O/C, H/C) chemical space. The combination of k-means analysis with findings from chemoselective reactions allowed the distinctive hydroxyl functionalities across the samples to be inferred. Our results indicate that the hexane-soluble fraction contained numerous molecules containing primary and secondary alcohols, while the water-soluble fraction displayed diverse groups of oxygenated compounds, clustered near to carbohydrate-like and pyrolytic humin-like materials. Despite its high oxygen content, the water-soluble fraction showed minimal changes in viscosity during aging. In contrast, a significant increase in viscosity was observed in the water-insoluble materials, specifically, the low- and high-molecular-weight lignin fractions (LMWL and HMWL, respectively). Among these two fractions, the HMWL exhibited the highest increase in viscosity after only 4 h of accelerated aging. Our results indicate that this aging behavior is attributed to an increased number of molecular compositions containing phenolic groups. Thus, the chemical compositions within the HMWL are the major contributors to the viscosity changes in the bio-oil under accelerated aging conditions. This highlights the crucial role of oxygen functionality in bio-oil aging, suggesting that a high oxygen content alone does not necessarily correlate with an increase of viscosity. Unlike other bio-oil categorization methods based on constrained molecule locations within the van Krevelen compositional space, k-means clustering can identify patterns within ultrahigh-resolution data inherent to the unique chemical fingerprint of each sample.

2.
Biomédica (Bogotá) ; 43(3): 343-351, sept. 2023. tab
Artigo em Espanhol | LILACS | ID: biblio-1533945

RESUMO

Introducción. Las radiografías continúan usándose ampliamente, subestimando los riesgos. Esto sucede, especialmente, en las unidades de cuidado neonatal, lo que implica que los neonatos reciben una dosis de radiación ionizante mayor que los adultos. Objetivo. Cuantificar las dosis de radiación recibidas al tomar radiografías y evaluar los posibles factores asociados con el aumento de la dosis. Materiales y métodos. Se llevó a cabo un estudio observacional de 160 neonatos de la Unidad de Recién Nacidos del Hospital Universitario San Ignacio, Bogotá, Colombia. Se consideró como variable dependiente la dosis de entrada en piel por cada radiografía. Se hizo la caracterización de los pacientes, seguida de un análisis multivariado con regresión lineal múltiple para identificar factores asociados. Resultados. Se analizaron 160 pacientes y 492 radiografías en total. Entre los hallazgos más frecuentes, se encuentran: pacientes de sexo masculino (n=87; 54,4 %), nacimiento por cesárea (n=122; 76,3 %) e indicación de toma de radiografías por dificultad respiratoria (n=123; 24,9 %). El 1,8 % (n=9) de los pacientes no tenían una indicación para la toma de la radiografía. La radiografía más frecuente fue la de tórax (n=322; 65,4 %). La mayoría de las radiografías se tomaron con el equipo computarizado (n=352; 71,5 %) y no con el digital (n=140, 28,4 %). La mediana de la dosis de entrada en piel con el equipo computarizado fue de 0,112 mGy (0,022; 0,134 mGy) y, con el equipo digital, de 0,020 mGy (0,019, 0,022 mGy). Conclusiones. Se cuantificaron las dosis de radiación absorbida en neonatos, general y específica, con el equipo computarizado y el digital. Se identificaron mayores dosis con el equipo computarizado. Se reconoció la interacción entre el equipo computarizado con menores edades gestacionales corregidas como principal factor para el aumento de la dosis. Además, se reconoció la relación entre el equipo computarizado y una menor edad gestacional corregida, como principal factor para una mayor dosis.


Introduction. Radiographs are still widely used, underestimating the risks. This situation is frequent in neonatal care units, generating radiation doses than in adults. Objective. To quantify the received radiation doses when performing radiographs on neonates and the possible factors associated with higher doses. Materials and methods. We performed an observational study of 160 neonates from the newborn unit of the Hospital Universitario San Ignacio, Bogotá, Colombia. We considered the input dose of each radiograph as the dependent variable. Patients were characterized and a multivariate analysis with multiple linear regression was performed to identify associated factors. Results. We analyzed 160 newborns and 492 radiographs. The most frequent findings were male patients (n=87, 54.4%), cesarean delivery (n=122, 76.3%), and radiograph indication for respiratory distress (n=123, 24.9%). One-point eight percent of the patients (n=9) did not have radiograph indication. The most frequently taken radiograph was chest (322, 65.4%). Most radiographs were taken with a computerized equipment (n=352, 71.5%), compared to a digital one (n=140, 28.4%). The median input dose with computerized equipment was 0.112 mGy (0.022, 0.134 mGy), and with the digital equipment was 0.020 mGy (0.019, 0.022 mGy). Conclusions. The general and specific absorbed radiation doses were measured in neonates with a computerized and a digital equipment. We identified higher doses with the computerized equipment. In addition, it was recognized the correlation between computerized radiography equipment with lower corrected gestational ages as the main factor for dose increase.


Assuntos
Doses de Radiação , Recém-Nascido , Radiação , Radiografia , Fatores de Risco
3.
Energy Fuels ; 36(22): 13518-13525, 2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36425344

RESUMO

Base oil is a main component of engine oil that enables smooth operation of an internal combustion engine. There are two types of base oils, such as mineral oil and synthetic oil. In this study, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and gas chromatography-mass spectrometry (GC-MS) were used to characterize the base oils. One difficulty in analyzing base oils using MS is that the ionization of alkanes can be problematic due to low ionization efficiencies and the predominance of fragmentation. Despite these limitations, the combination of GC-MS and FT-ICR MS data can provide qualitative insights into the composition differences for these various sample types. The distinctive total ion chromatogram obtained by GC-MS of the different base oils allowed the classification of mineral oil from synthetic oil. The additional structural characteristics of paraffinic compounds were also inferred by GC-MS. FT-ICR MS coupled to two different ionization methods, atmospheric pressure photoionization (APPI) and atmospheric pressure chemical ionization (APCI), was tested for the analysis of base oils. It was determined that APPI was suitable for the analysis of aliphatic hydrocarbon compounds, where APPI minimizes the decomposition of hydrocarbon compounds compared to atmospheric pressure chemical ionization. Using APPI FT-ICR MS, the components of the oils were characterized, including not only paraffinic compounds but also cyclic compounds. In addition, the alpha olefin monomer of the synthetic oil was determined, and the homogeneity of the branched compound of the synthetic base oil was confirmed using GC-MS and FT-ICR MS results.

4.
Anal Chem ; 94(21): 7536-7544, 2022 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-35576165

RESUMO

Bio-oils are precursors for biofuels but are highly corrosive necessitating further upgrading. Furthermore, bio-oil samples are highly complex and represent a broad range of chemistries. They are complex mixtures not simply because of the large number of poly-oxygenated compounds but because each composition can comprise many isomers with multiple functional groups. The use of hyphenated ultrahigh-resolution mass spectrometry affords the ability to separate isomeric species of complex mixtures. Here, we present for the first time, the use of this powerful analytical technique combined with chemical reactivity to gain greater insights into the reactivity of the individual isomeric species of bio-oils. A pyrolysis bio-oils and its esterified bio-oil were analyzed using gas chromatography coupled to Fourier transform ion cyclotron resonance mass spectrometry, and in-house software (KairosMS) was used for fast comparison of the hyphenated data sets. The data revealed a total of 10,368 isomers in the pyrolysis bio-oil and an increase to 18,827 isomers after esterification conditions. Furthermore, the comparison of the isomeric distribution before and after esterification provide new light on the reactivities within these complex mixtures; these reactivities would be expected to correspond with carboxylic acid, aldehyde, and ketone functional groups. Using this approach, it was possible to reveal the increased chemical complexity of bio-oils after upgrading and target detection of valuable compounds within the bio-oils. The combination of chemical reactions alongside with in-depth molecular characterization opens a new window for the understanding of the chemistry and reactivity of complex mixtures.


Assuntos
Óleos de Plantas , Polifenóis , Biocombustíveis/análise , Biomassa , Misturas Complexas , Cromatografia Gasosa-Espectrometria de Massas , Temperatura Alta , Óleos de Plantas/química , Polifenóis/química
5.
Bull Natl Res Cent ; 46(1): 286, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36593896

RESUMO

Background: Paracoccidioidomycosis is a systemic fungal infection that is potentially fatal, and the most prevalent of its kind in Latin America. The predisposition to infection appears to be related to abnormalities in cellular immunity, given its low prevalence in endemic regions. The role of myeloperoxidase deficiency has not been elucidated. Case presentation: We present a case of 48-year-old female patient with acute lymphoblastic leukemia, stem cell transplant candidate, who developed a fever with lymphadenopathy and lung nodules, consistent with paracoccidioidomycosis infection, in whom a myeloperoxidase deficiency was later discovered. The treatment of the hematologic malignancy had a good impact solving the enzymatic deficiency and antifungal therapy achieve controlling the infection. Conclusions: This case lays out the possible association between acute leukemia, an alteration in neutrophil function (needed to fight fungal infections) and an infection due to Paracoccidioides brasiliensis.

6.
Salud UNINORTE ; 37(2): 390-406, mayo-ago. 2021. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1377257

RESUMO

RESUMEN Objetivo: Analizar las dimensiones culturales del concepto pie diabético en personas con diabetes mellitus y en estudiantes de medicina. Material y métodos: Estudio descriptivo exploratorio con base en los fundamentos de la antropología cognitiva y la teoría del consenso cultural. Participaron 40 personas (20 personas con diabetes y 20 estudiantes de medicina de séptimo semestre). El estudio se realizó en Guadalajara (México), en un hospital de segundo nivel, en los primeros tres meses de 2019. Se utilizaron listados libres y pile sort para identificar el contenido y la organización de las dimensiones. En el caso de los valores agregados, las matrices fueron analizadas mediante conglomerados jerárquicos. En el caso de los valores individuales, las matrices fueron analizadas mediante un modelo de consenso cultural. Resultados: Para las personas con diabetes, el concepto de pie diabético se conformó por las dimensiones de consecuencias y prevención. Para los estudiantes de medicina, el concepto de pie diabético se conformó por las dimensiones consecuencias y complicaciones. Se encontró consenso cultural en ambos grupos (Razón F1:F2, personas con diabetes: 3.14; estudiantes de medicina: 6.73). Las dimensiones tuvieron valores de ajuste adecuados: stress 0.21 en las personas con diabetes y 0.13 en los estudiantes. Conclusiones: Gracias a los resultados y acercamiento hacia ambos grupos, se pudieron reconocer elementos claves para la futura aplicación de programas de prevención para la salud, y una atención más integral para las personas con diabetes mellitus.


ABSTRACT Objective: Analyze the cultural dimensions of the diabetic foot concept in people with diabetes mellitus and in medical students. Material and Methods: Exploratory descriptive study based on the foundations of cognitive anthropology and the theory of cultural consensus. Forty people participated (20 people with diabetes and 20 medical students in the seventh semester). The study was conducted in Guadalajara, Mexico, in a second level hospital, in the first three months of the year 2019. Free lists and pile sort were used to identify the content and the organization of the dimensions. In the case of the aggregated values, hierarchical conglomerates analyzed the matrices. In the case of individual values, the matrices were analyzed using a cultural consensus model. Results: People with diabetes mellitus conformed the concept of diabetic foot by the dimensions of consequences and complications, whereas the medical students conformed the concept by the dimensions of consequences and complications. The cultural consensus was found in both groups with the following reasons F1:F2, people with diabetes: 3.14; medical students: 6.73. The dimensions had adequate values with the stress of 0.21 for the people with diabetes, and of 0.13 for the medical students. Conclusions: Gratefully, these results and the approach towards these two groups' key elements could be found for a future application of programs of health prevention and deeper and integral treatment process for the people with diabetes mellitus.

7.
Invest Ophthalmol Vis Sci ; 58(7): 2884-2890, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28586912

RESUMO

Purpose: MicroRNAs (miRNAs) are small, endogenous noncoding RNAs that have been detected in human aqueous humor (AH). Prior studies have pooled samples to obtain sufficient quantities for analysis or used next-generation sequencing. Here, we used PCR arrays with preamplification to identify and compare miRNAs from individual AH samples between patients with primary open-angle glaucoma (POAG) and normal controls. Methods: AH was collected before cataract surgery from six stable, medically treated POAG patients and eight age-matched controls. Following reverse transcription and preamplification, individual patient samples were profiled on Taqman Low Density MicroRNA Array Cards. Differentially expressed miRNAs were stratified for fold changes larger than ±2 and for significance of P < 0.05. Significant Kyoto Encyclopedia of Genes and Genomes pathways influenced by the differentially expressed miRNAs were identified using the predicted target module of the miRWalk 2.0 database. Results: This approach detected 181 discrete miRNAs, which were consistently expressed across all samples of both experimental groups. Significant up-regulation of miR-518d and miR-143, and significant down-regulation of miR-660, was observed in the AH of POAG patients compared with controls. These miRNAs were predicted to reduce cell proliferation and extracellular matrix remodeling, endocytosis, Wnt signaling, ubiquitin-mediated proteolysis, and adherens junction function. Conclusions: This pilot study demonstrates that miRNA expression within the AH of POAG patients differs from age-matched controls. AH miRNAs exhibit potential as biomarkers of POAG, which merits further investigation in a larger case-controlled study. This technique provides a cost-effective and sensitive approach to assay miRNAs in individual patient samples without the need for pooling.


Assuntos
Humor Aquoso/metabolismo , Regulação da Expressão Gênica , Glaucoma de Ângulo Aberto/genética , MicroRNAs/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Idoso , Feminino , Glaucoma de Ângulo Aberto/metabolismo , Humanos , Masculino , MicroRNAs/biossíntese , Pessoa de Meia-Idade , Projetos Piloto , Reprodutibilidade dos Testes
8.
Rev. univ. psicoanál ; (16): 51-60, nov. 2016.
Artigo em Espanhol | LILACS | ID: biblio-910843

RESUMO

El presente artículo aborda la complejidad que plantea el diagnóstico diferencial en psicoanálisis, a partir de un caso mencionado en diversas ocasiones en la obra de Freud, considerado por él como "neurosis obsesiva grave", cuestión que es objeto de debate de actualidad. Para ello se pondrá en tensión la relación fenómeno-estructura considerando el problema de la dirección de la cura y la envoltura formal del síntoma. Se desarrollará la discusión contemporánea sobre las razones del fracaso de este tratamiento, así como el cuestionamiento del diagnóstico que se basa en diferentes hallazgos historiográficos, proponiéndolo como una melancolía. Se introducirá como novedad en dicho debate el carácter ineludible de la articulación entre la presentación del síntoma y la dimensión de la transferencia, que se produce en esta ocasión en una dirección de la cura de parte de Freud que contribuye al agravamiento del caso.


This article approaches the complexity implied in differential diagnosis in psychoanalysis, by taking a case mentioned in diverse occasions in the work of Freud. This case was considered by him as a "serious obsessional neurosis", affirmation that is object of current debates. For this purpose, relationship phenomenon-structure will be put in tension with the problem of the direction of the cure and the formal envelope of the symptom. The contemporary discussion will be developed, taking into account the reasons of the failure of this treatment, as well as the questioning of the diagnosis that is based on different historiographic findings, proposing it as a melancholy. It will be introduced as newness in this debate the inescapable character of the joint between the presentation of the symptom and the dimension of the transference, produced in this occasion in a direction of the cure conducted by Freud that contributes to the worsening of the case.


Assuntos
Humanos , Diagnóstico Diferencial , Psicanálise , Transtorno Depressivo , Transtorno Obsessivo-Compulsivo
9.
Rev. colomb. biotecnol ; 17(2): 76-84, jul.-dic. 2015. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-769083

RESUMO

Aspidosperma polyneuron es un especie nativa de la región neotropical, en países como Colombia, Venezuela, Perú, Brasil, Argentina y Paraguay, propio de bosques semideciduos, catalogada desde 1998 por la UICN como "En Peligro (EN)", debido a que sus poblaciones naturales fueron sometidas a una intensa explotación con fines madereros y su hábitat se vio seriamente degradado por actividades agrícolas y silvopastoriles. Las dificultades para su regeneración natural y el enraizamiento de las estacas, hace que el cultivo in vitro sea una eficaz herramienta para contrarrestar las dificultades reproductivas que presenta. Sin embargo, la presencia de contaminantes que afectan la viabilidad de los explantes, precisa el desarrollo de protocolos que permitan el establecimiento in vitro de la especie. El objetivo de la presente investigación fue lograr el establecimiento aséptico y la inducción de la callogénesis en explantes de A. polyneuron, mediante la evaluación de diferentes tratamientos de desinfección. Los explantes se obtuvieron de individuos de regeneración natural, en el municipio de Armero, departamento del Tolima, los cuales se sumergieron en agua destilada con una gota de Tween® 80 por cada 100 ml, durante 10 minutos y lavados con agua destilada estéril. Se utilizaron como agentes desinfectantes, el hipoclorito de sodio y el dicloruro de mercurio a distintas concentraciones y tiempos de inmersión. De los explantes utilizados: ápices, segmentos nodales y láminas foliares, este último fue seleccionado por su capacidad de producir callos friables de color verde, para lo cual una desinfección con dicloruro de mercurio (HgCl2) al 0.125% durante 10 minutos fue suficiente para el control de la contaminación y bajos índices de oxidación.


Aspidosperma polyneuron is a species native to the Neotropics, in countries like Colombia, Venezuela, Peru, Brazil, Argentina and Paraguay, typical of semi-deciduous forests, catalogued since 1998 by the IUCN as "Endangered (EN)", because its natural populations were subjected to an intense exploitation for timber and its habitat was seriously degraded by agricultural and silvopastoral activities. The difficulties for its natural regeneration and the rooting of cuttings, make the in vitro culture an efficient tool to counteract the reproductive difficulties that it presents. However, the presence of pollutants that affect the viability of the explants needs the development of protocols that allow the in vitro establishment of this species. The objective of this research was to achieve aseptic establishment and the induction of callogenesis in explants of A. polyneuron, by evaluating different disinfection treatments. The expants were obtained from individuals of natural regeneration, in the Municipality of Armero in the Department of Tolima, which were immersed in distilled water with a drop of Tween® 80 for each 100 ml, for 10 minutes and then rinsed with sterile distilled water. There were used as disinfectant agents, sodium hypochlorite and mercury dichloride in different concentrations and times of immersion. Among the used explants: buds, nodal segments and leaf blades, the last one was selected for its capacity of producing friable and green callosity, for which a disinfection with mercury dichloride (HgCl2) 0.125% for 10 minutes was enough for contamination control and low indexes of oxidation.

10.
Bogotá; s.n; 2012. 19 p. tab.
Tese em Espanhol | LILACS, MOSAICO - Saúde integrativa | ID: biblio-877031

RESUMO

La acupuntura forma parte de la medicina tradicional china como sistema médico complejo de la medicina alternativa y complementaria; ha sido objeto de múltiples investigaciones en diferentes patologías, que evalúan su eficacia comparada con otros tratamientos estandarizados. Uno de los temas más comúnmente revisados es el manejo del dolor y, en este campo, las enfermedades de origen reumatológico como la osteoartritis, que hasta la presente no tiene cura y ha sido una de las más ampliamente estudiadas; en esta terapéutica se encuentra evidencia que apoya su empleo como coadyuvante del tratamiento convencional establecido hasta el momento.


Assuntos
Humanos , Osteoartrite/terapia , Acupuntura , Manejo da Dor , Medicina Tradicional Chinesa
11.
Hepat Res Treat ; 2011: 582945, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22114738

RESUMO

Hepatocellular Carcinoma (HCC) is a leading cause of cancer-related death worldwide. Globally, the most important HCC risk factors are Hepatitis B Virus (HBV) and/or Hepatitis C Virus (HCV), chronic alcoholism, and dietary exposure to aflatoxins. We have described the epidemiological pattern of 202 HCC samples obtained from Colombian patients. Additionally we investigated HBV/HCV infections and TP53 mutations in 49 of these HCC cases. HBV biomarkers were detected in 58.1% of the cases; HBV genotypes F and D were characterized in three of the samples. The HCV biomarker was detected in 37% of the samples while HBV/HCV coinfection was found in 19.2%. Among TP53 mutations, 10.5% occur at the common aflatoxin mutation hotspot, codon 249. No data regarding chronic alcoholism was available from the cases. In conclusion, in this first study of HCC and biomarkers in a Colombian population, the main HCC risk factor was HBV infection.

12.
J Cataract Refract Surg ; 32(1): 21-32, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16516775

RESUMO

PURPOSE: To determine the aberrations induced in wavefront-guided laser refractive surgery due to shifts in pupil center location from when aberrations are measured preoperatively (over a dilated pupil) to when they are corrected surgically (over a natural pupil). SETTING: Center for Visual Science and Department of Ophthalmology, University of Rochester, Rochester, New York, USA. METHODS: Shifts in pupil center were measured between dilated phenylephrine hydrochloride (Neo-Synephrine [2.5%]) and nonpharmacological mesopic conditions in 65 myopic eyes treated with wavefront-guided laser in situ keratomileusis (Technolas 217z, Bausch & Lomb). Each patient's preoperative and 6-month postoperative wave aberrations were measured over the dilated pupil. Aberrations theoretically induced by decentration of a wavefront-guided ablation were calculated and compared with those measured 6 months postoperatively (6.0 mm pupil). RESULTS: The mean magnitude of pupil center shift was 0.29 mm +/- 0.141 (SD) and usually occurred in the inferonasal direction as the pupil dilated. Depending on the magnitude of shift, the fraction of the higher-order postoperative root-mean-square wavefront error that could be due theoretically to pupil center decentrations was highly variable (mean 0.26 +/- 0.20 mm). There was little correlation between the calculated and 6-month postoperative wavefronts, most likely because pupil center decentrations are only 1 of several potential sources of postoperative aberrations. CONCLUSIONS: Measuring aberrations over a Neo-Synephrine-dilated pupil and treating them over an undilated pupil typically resulted in a shift of the wavefront-guided ablation in the superotemporal direction and an induction of higher-order aberrations. Methods referencing the aberration measurement and treatment with respect to a fixed feature on the eye will reduce the potential for inducing aberrations due to shifts in pupil center.


Assuntos
Córnea/cirurgia , Ceratomileuse Assistida por Excimer Laser In Situ/efeitos adversos , Midriáticos/administração & dosagem , Miopia/cirurgia , Complicações Pós-Operatórias , Pupila/efeitos dos fármacos , Erros de Refração/etiologia , Adulto , Córnea/fisiopatologia , Humanos , Ceratomileuse Assistida por Excimer Laser In Situ/métodos , Fenilefrina/administração & dosagem , Pupila/fisiologia
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