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1.
Pediatr Cardiol ; 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38502199

RESUMO

Recent advances in available percutaneous device technology require accurate measurements and quantification of relationships between right ventricular outflow tract (RVOT) structures in children with and without congenital heart disease to determine device suitability. To date, no population study has described normal reference ranges of these measurements by computed tomography (CT). We aimed to establish normative values for four CT-derived measurements between RVOT structures from a heterogeneous population without heart disease and develop z scores useful for clinical practice. Patients without heart disease who underwent cardiac CT between April 2014 and February 2021 at Children's Hospital Colorado were included. Distance between the right ventricular (RV) apex to pulmonary valve (PV), PV to pulmonary trunk bifurcation, and bifurcation to the right and left pulmonary artery was measured. Previously validated models were used to normalize the measurements and calculate Z scores. Each measurement was plotted against BSA and Z scores distributions were used as reference lines. Three-hundred and sixty-four healthy patients with a mean age of 8.8 years (range 1-21), 58% male, and BSA of 1 m2 (range 0.4-2.1) were analyzed. The Haycock formula was used to present data as predicted values for a given BSA and within equations relating each measurement to BSA. Predicted values and Z-score boundaries for all measurements are presented.We report CT-derived normative data for four measurements between RVOT structures from a heterogeneous cohort of healthy children. Knowledge of this normative data will be useful in both determining device fit and customizing future devices to accommodate the diverse pediatric size range.

2.
Nature ; 628(8006): 99-103, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38538794

RESUMO

Stable aluminosilicate zeolites with extra-large pores that are open through rings of more than 12 tetrahedra could be used to process molecules larger than those currently manageable in zeolite materials. However, until very recently1-3, they proved elusive. In analogy to the interlayer expansion of layered zeolite precursors4,5, we report a strategy that yields thermally and hydrothermally stable silicates by expansion of a one-dimensional silicate chain with an intercalated silylating agent that separates and connects the chains. As a result, zeolites with extra-large pores delimited by 20, 16 and 16 Si tetrahedra along the three crystallographic directions are obtained. The as-made interchain-expanded zeolite contains dangling Si-CH3 groups that, by calcination, connect to each other, resulting in a true, fully connected (except possible defects) three-dimensional zeolite framework with a very low density. Additionally, it features triple four-ring units not seen before in any type of zeolite. The silicate expansion-condensation approach we report may be amenable to further extra-large-pore zeolite formation. Ti can be introduced in this zeolite, leading to a catalyst that is active in liquid-phase alkene oxidations involving bulky molecules, which shows promise in the industrially relevant clean production of propylene oxide using cumene hydroperoxide as an oxidant.

3.
Cryst Growth Des ; 24(3): 938-946, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38344677

RESUMO

Zeolite stability, in terms of lattice energy, is revisited from a crystal-chemistry point of view. A linearized equation relates the zeolite lattice energy using simple structural data readily available from experiments or modeling. The equation holds for a large range of zeolite energies, up to 3 eV per tetrahedron with respect to quartz, and has been validated internally via two simple machine learning automatic procedures for data fitting/reference partitions and externally using data from recently synthesized zeolites. The approach is certain in locating those recently synthesized zeolites in the energy range of those experimentally known zeolites used in the parametrization of the linearized equation. Hidden intrinsic structural data-energy correlations were found for data sets built from energy-relaxed structures along with energy values computed using the same energy functions employed in the structural relaxation. The asymmetry of the structural features is relevant for an accurate description of the energy.

4.
ACS Appl Mater Interfaces ; 15(33): 39594-39605, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37579193

RESUMO

Metal-organic frameworks (MOFs) have become promising materials for multiple applications due to their controlled dimensionality and tunable properties. The incorporation of chirality into their frameworks opens new strategies for chiral separation, a key technology in the pharmaceutical industry as each enantiomer of a racemic drug must be isolated. Here, we describe the use of a combination of computational modeling and experiments to demonstrate that high-performance liquid chromatography (HPLC) columns packed with TAMOF-1 as the chiral stationary phase are efficient, versatile, robust, and reusable with a wide array of mobile phases (polar and non-polar). As proof of concept, in this article, we report the resolution with TAMOF-1 HPLC columns of nine racemic mixtures with different molecular sizes, geometries, and functional groups. Initial in silico studies allowed us to predict plausible separations in chiral compounds from different families, including terpenes, calcium channel blockers, or P-stereogenic compounds. The experimental data confirmed the validity of the models and the robust performance of TAMOF-1 columns. The added value of in silico screening is an unprecedented achievement in chiral chromatography.

5.
Nephron ; 147(9): 521-530, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36808092

RESUMO

BACKGROUND: The association between potassium (sK) level trajectory and mortality or the need for kidney replacement therapy (KRT) during acute kidney injury (AKI) has not been adequately explored. METHODS: In this prospective cohort, AKI patients admitted to the Hospital Civil de Guadalajara were enrolled. Eight groups based on the sK (mEq/L) level trajectories during 10 days of hospitalization were created (1) normokalemia (normoK), defined as sK between 3.5-5.5; (2) hyperkalemia to normoK; (3) hypokalemia to normoK; (4) fluctuating potassium; (5) persistent hypoK; (6) normoK to hypoK; (7) normoK to hyperK; (8) persistent hyperK. We assessed the association of sK trajectories with mortality and the need for KRT. RESULTS: A total of 311 AKI patients were included. The mean age was 52.6 years, and 58.6% were male. AKI stage 3 was present in 63.9%. KRT started in 36% patients, and 21.2% died. After adjusting for confounders, 10-day hospital mortality was significantly higher in groups 7 and 8 (OR, 1.35 and 1.61, p < 0.05, for both, respectively), and KRT initiation was higher only in group 8 (OR 1.38, p < 0.05) compared with group 1. Mortality in different subgroups of patients in group 8 did not change the primary results. CONCLUSION: In our prospective cohort, most patients with AKI had alterations in sK+. NormoK to hyperK and persistent hyperK were associated with death, while only persistent hyperK was correlated with the need for KRT.


Assuntos
Injúria Renal Aguda , Hiperpotassemia , Hipopotassemia , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Estudos Prospectivos , Potássio , Hipopotassemia/complicações , Injúria Renal Aguda/complicações , Hiperpotassemia/complicações
6.
Nanoscale ; 15(7): 3504-3519, 2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36723023

RESUMO

We have studied the clusters involved in the initial stages of nucleation of Zeolitic Imidazolate Frameworks, employing a wide range of computational techniques. In the pre-nucleating solution, the prevalent cluster is the ZnIm4 cluster (formed by a zinc cation, Zn2+, and four imidazolate anions, Im-), although clusters such as ZnIm3, Zn2Im7, Zn2Im7, Zn3Im9, Zn3Im10, or Zn4Im12 have energies that are not much higher, so they would also be present in solution at appreciable quantities. All these species, except ZnIm3, have a tetrahedrally coordinated Zn2+ cation. Small ZnxImy clusters are less stable than the ZnIm4 cluster. The first cluster that is found to be more stable than ZnIm4 is the Zn41Im88 cluster, which is a disordered cluster with glassy structure. Bulk-like clusters do not begin to be more stable than glassy clusters until much larger sizes, since the larger cluster we have studied (Zn144Im288) is still less stable than the glassy Zn41Im88 cluster, suggesting that Ostwald's rule (the less stable polymorph crystallizes first) could be fulfilled, not for kinetic, but for thermodynamic reasons. Our results suggest that the first clusters formed in the nucleation process would be glassy clusters, which then undergo transformation to any of the various crystal structures possible, depending on the kinetic routes provided by the synthesis conditions. Our study helps elucidate the way in which the various species present in solution interact, leading to nucleation and crystal growth.

7.
ACS Appl Mater Interfaces ; 14(27): 30772-30785, 2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35793095

RESUMO

Separation of volatile organic compounds is one of the most studied processes in industry. TAMOF-1 is a homochiral metal-organic framework with a crystalline network of interconnected ≈1 nm channels and has high thermal and chemical stability. Thanks to these features, it can resolve racemic mixtures of chiral drugs as a chiral stationary phase in chromatography. Interestingly, the particular shape and size of its channels, along with the presence of metallic centers and functional groups, allow establishing weak but significant interactions with guest molecules. This opens interesting possibilities not only to resolve racemates but also to separate other organic mixtures, such as saturated/unsaturated and/or linear/branched molecules. In search of these applications, we have studied the separation of volatile organic compounds in TAMOF-1. Monte Carlo simulations in the grand-canonical ensemble have been carried out to evaluate the separation of the selected molecules. Our results predict that TAMOF-1 is able to separate xylene isomers, hexane isomers, and benzene-cyclohexane mixtures. Experimental breakthrough analysis in the gas phase and also in the liquid phase confirms these predictions. Beds of TAMOF-1 are able to recognize the substitution in xylenes and the branching in hexanes, yielding excellent separation and reproducibility, thanks to the chemical and mechanical features of this material.

8.
J Chem Inf Model ; 62(24): 6423-6435, 2022 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-35576452

RESUMO

Many key features in photovoltaic perovskites occur in relatively long time scales and involve mixed compositions. This requires realistic but also numerically simple models. In this work we present a transferable classical force field to describe the mixed hybrid perovskite MAxFA1-xPb(BryI1-y)3 for variable composition (∀x, y ∈ [0, 1]). The model includes Lennard-Jones and Buckingham potentials to describe the interactions between the atoms of the inorganic lattice and the organic molecule, and the AMBER model to describe intramolecular atomic interactions. Most of the parameters of the force field have been obtained by means of a genetic algorithm previously developed to parametrize the CsPb(BrxI1-x)3 perovskite (Balestra et al. J. Mater. Chem. A. 2020, DOI: 10.1039/d0ta03200j). The algorithm finds the best parameter set that simultaneously fits the DFT energies obtained for several crystalline structures with moderate degrees of distortion with respect to the equilibrium configuration. The resulting model reproduces correctly the XRD patterns, the expansion of the lattice upon I/Br substitution, and the thermal expansion coefficients. We use the model to run classical molecular dynamics simulations with up to 8600 atoms and simulation times of up to 40 ns. From the simulations we have extracted the ion diffusion coefficient of the pure and mixed perovskites, presenting for the first time these values obtained by a fully dynamical method using a transferable model fitted to first-principles calculations. The values here reported can be considered as the theoretical upper limit, that is, without grain boundaries or other defects, for ion migration dynamics induced by halide vacancies in photovoltaic perovskite devices under operational conditions.

9.
Chemistry ; 27(72): 18109-18117, 2021 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-34730258

RESUMO

One common strategy in the search for new zeolites is the use of organic structure-directing agents (OSDA). Typically, one seeks to achieve a high specificity in the structure-directing effect of the OSDA. This study shows, however, that an OSDA lacking strong specificity towards any particular zeolite may provide opportunities for discovery when other synthesis parameters are systematically screened. Thus, 1-methyl-2-ethyl-3-n-propylimidazolium has allowed to crystallize the new large/medium pore zeolite HPM-16 as well as the recently reported extra-large pore -SYT and the medium/small pore and chiral STW. The sophisticated OSDA originally affording -SYT and the new simple OSDA have very little in common, both in terms of size, shape and flexibility, while both may still direct the synthesis of the same zeolite. In fact, molecular simulations show that the new OSDA is located in three different positions of the -SYT structure, including the discrete 8MR where the original organic could not fit.

10.
Angew Chem Int Ed Engl ; 60(37): 20249-20252, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34309150

RESUMO

HPM-16 is a highly porous germanosilicate zeolite with an interrupted framework that contains a three-dimensional system of 12+10×10(12)×12+10-membered ring (MR) pores. The 10(12) MR pore in the b direction is a 10 MR pore with long 12 MR stretches forming 30 Šlong tubular supercages. Along one direction the 10 MR pores are fused, meaning that the separation between adjacent pores consists of a single tetrahedron that is, additionally, connected to only three additional tetrahedra (a Q3 ). These fused pores are thus decorated by T-OH groups along the whole diffusion path, creating a hydrophilic region embedded in an otherwise essentially hydrophobic environment. The structure is built from highly porous 12×12×12 MR uninterrupted layers that are connected to each other through Q3 producing a second system of 10×10×10 MR pores. This zeolite can be extensively degermanated yielding a material with high thermal stability, despite its interrupted nature.

11.
Appl Biochem Biotechnol ; 193(11): 3553-3569, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34312785

RESUMO

The effects of water activity (aw), pH, and temperature on transglycosylation activity of α-L-fucosidase from Thermotoga maritima in the synthesis of fucosylated oligosaccharides were evaluated using different water-organic cosolvent reaction systems. The optimum conditions of transglycosylation reaction were the pH range between 7 and 10 and temperature 90-95 °C. The addition of organic cosolvent decreased α-L-fucosidase transglycosylation activity in the following order: acetone > dimethyl sulfoxide (DMSO) > acetonitrile (0.51 > 0.42 > 0.18 mM/h). However, the presence of DMSO and acetone enhanced enzyme-catalyzed transglycosylation over hydrolysis as demonstrated by the obtained transglycosylation/hydrolysis rate (rT/H) values of 1.21 and 1.43, respectively. The lowest rT/H was calculated for acetonitrile (0.59), though all cosolvents tested improved the transglycosylation rate in comparison to a control assay (0.39). Overall, the study allowed the production of fucosylated oligosaccharides in water-organic cosolvent reaction media using α-L-fucosidase from T. maritima as biocatalyst.


Assuntos
Proteínas de Bactérias/química , Fucose/química , Oligossacarídeos/síntese química , Thermotoga maritima/enzimologia , alfa-L-Fucosidase/química , Solventes/química , Água/química
12.
Rev. colomb. psicol ; 30(1): 133-147, ene.-jun. 2021. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1251623

RESUMO

Abstract Parental involvement in children's education is commonly accepted as beneficial. However, family social class plays a crucial role in the efficacy of homework help. In a comparative case study, a low-income immigrant family from Mexico and a middle-income family in Los Angeles were observed helping their children with math homework and were asked questions about goals, tutoring strategies, and beliefs about learning. Qualitative analysis focused on two effective teaching methods: scaffolding and productive struggle. The low-income mother with little formal education provided direct help rather than a scaffold, and disapproved of hard problems. However, an older sibling with more education than her mother used scaffolding and believed that difficult problems aid learning. In these respects, she resembled the college-educated middle-income mother. The sister exemplifies how older siblings in immigrant families provide bridges to educational achievement for younger siblings. We suggest effective ways for schools to involve parents who lacked educational opportunity themselves to participate in the education of their children.


Resumen La participación de los padres en la educación de sus niños es establecida como beneficiosa. Sin embargo, la clase social de la familia tiene una fuerte influencia sobre la eficacia de su ayuda con las tareas. En un estudio de caso comparativo, una familia inmigrante de México, de bajos ingresos, y una familia de Los Ángeles, de medianos ingresos, fueron observadas ayudando a sus niñas con deberes en matemáticas. Además, el investigador hizo preguntas sobre metas, estrategias de enseñanza y creencias sobre el aprendizaje. El análisis cualitativo se centró en dos métodos efectivos de enseñanza: proporcionar el aprendizaje de manera de andamio y estimular la lucha productiva. La madre de ingresos bajos proporcionó apoyo directo a su hija en lugar de proporcionar un andamio, y ella desaprobó los problemas difíciles; sin embargo, una hermana mayor con más educación que la madre proporcionó un andamio y creyó que los problemas difíciles ayudan al aprendizaje. En estos aspectos, la hermana mayor era similar a la madre de ingresos medios con educación universitaria. La hermana demuestra cómo hermanos mayores en las familias inmigrantes proporcionan puentes al éxito educativo para los hermanos menores. Sugerimos modos efectivos para que las escuelas puedan alentar a los padres con falta de oportunidades educativas a participar en la educación de sus hijos.

13.
Radiologia (Engl Ed) ; 63(3): 291-304, 2021.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-33853713

RESUMO

Ultrasonography is the imaging technique of choice for studying the digestive tract in pediatric patients from the neonatal period to adolescence. Its dynamic character, absence of radiation, and scant preparation required make ultrasonography preferable to contrast-enhanced fluoroscopy, computed tomography, or magnetic resonance imaging. Technical advances in ultrasound, including high-resolution multifrequency probes, panoramic studies, color Doppler, Doppler with microvascularization, elastography, and contrast agents for use in children, have increased the sensitivity and specificity of this technique. Intestinal ultrasound is indicated for conditions with diverse etiologies and pathogenesis: congenital, infectious, inflammatory, tumor-related, and vascular. Knowledge of embryological development and the normal characteristics of the digestive tract help in identifying, recognizing, and interpreting the ultrasound findings of the different conditions in pediatric patients. This paper aims to show the indications for ultrasound studies of the digestive tract in children, the findings on these studies, and the management of the most common gastrointestinal conditions in pediatric patients.

14.
Abdom Radiol (NY) ; 46(7): 3280-3287, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33674961

RESUMO

PURPOSE: To identify specific contrast-enhanced CT (CECT) findings and develop a predictive model with logistic regression to differentiate fat-poor angiomyolipomas (fpAML) from papillary renal cell carcinomas (pRCC). METHODS: This is a single-institution retrospective study that assess CT features of histologically proven 67 pRCC and 13 fpAML. CECT variables were studied by means of univariate logistic regression. Variables included patients' demographics, tumor attenuation (unenhanced and at arterial, venous and excretory post-contrast phases), type of enhancement, morphological features (axial long and short diameters, long-short axis ratio (LSR) and tumor to kidney angle interface) and presence of visible calcifications or vessels. Those variables with a p ≤ 0.05 underwent standard stepwise logistic regression to find predictive combinations of clinical variables. Best models were evaluated by AUROC curves and were subjected to Leave-one-out cross validation to assess their robustness. RESULTS: Odds ratio (OR) between pRCC and fpAML was statistically significant for patient's gender, tumor attenuation in arterial, venous and excretory phases, tumor's long diameter, short diameter, LSR, type of enhancement, presence of intratumoral vessels and tumor-kidney angle interface. The best predictive model resulted in an area under the curve (AUC) of 0.971 and included gender, tumor-kidney angle interface and venous attenuation with the following equation: Log(p/1 - p) = - 2.834 + 4.052 * gender + - 0.066 * AngleInterface + 0.074 * VenousphaseHU. CONCLUSIONS: The combination of patients' gender, tumor to kidney angle interface and venous enhancement helps to distinguish fpAML from pRCC.


Assuntos
Angiomiolipoma , Carcinoma de Células Renais , Neoplasias Renais , Angiomiolipoma/diagnóstico por imagem , Carcinoma de Células Renais/diagnóstico por imagem , Diferenciação Celular , Meios de Contraste , Diagnóstico Diferencial , Humanos , Neoplasias Renais/diagnóstico por imagem , Estudos Retrospectivos , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X
16.
Dalton Trans ; 50(5): 1808-1815, 2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-33464245

RESUMO

The stability of metal-organic frameworks is a key factor in many applications in some fields that require working under harsh conditions. It is known that a large number of MOFs are vulnerable to humid air. It means that when they are exposed to water, a structural collapse of the crystal happens. In this work, Molecular Dynamics simulations using a reactive force field have been performed to study the stability of MOF-74 against the adsorption of catechol, resorcinol and hydroquinone in the presence of water. We reproduced the water instability of Zn-MOF-74 and we studied the resistance of the structure. Our simulations showed that the three isomers generate a volume change in the framework but the structural collapse does not happen. In contrast, for water-isomer mixtures, there is structural collapse. Not only do catechol, resorcinol and hydroquinone not behave as stabilizing agents but they do enhance the hydration effect on the structure.

17.
Psychol Med ; 51(14): 2446-2453, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-32338241

RESUMO

BACKGROUND: One hypothesis proposed to underlie formal thought disorder (FTD), the incoherent speech is seen in some patients with schizophrenia, is that it reflects impairment in frontal/executive function. While this proposal has received support in neuropsychological studies, it has been relatively little tested using functional imaging. This study aimed to examine brain activations associated with FTD, and its two main factor-analytically derived subsyndromes, during the performance of a working memory task. METHODS: Seventy patients with schizophrenia showing a full range of FTD scores and 70 matched healthy controls underwent fMRI during the performance of the 2-back version of the n-back task. Whole-brain corrected, voxel-based correlations with FTD scores were examined in the patient group. RESULTS: During 2-back performance the patients showed clusters of significant inverse correlation with FTD scores in the inferior frontal cortex and dorsolateral prefrontal cortex bilaterally, the left temporal cortex and subcortically in the basal ganglia and thalamus. Further analysis revealed that these correlations reflected an association only with 'alogia' (poverty of speech, poverty of content of speech and perseveration) and not with the 'fluent disorganization' component of FTD. CONCLUSIONS: This study provides functional imaging support for the view that FTD in schizophrenia may involve impaired executive/frontal function. However, the relationship appears to be exclusively with alogia and not with the variables contributing to fluent disorganization.


Assuntos
Afasia/patologia , Encéfalo/patologia , Função Executiva/fisiologia , Memória de Curto Prazo/fisiologia , Esquizofrenia/patologia , Adulto , Gânglios da Base/patologia , Disfunção Cognitiva , Córtex Pré-Frontal Dorsolateral/patologia , Feminino , Lobo Frontal/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pobreza , Lobo Temporal/patologia
18.
Radiología (Madr., Ed. impr.) ; 62(6): 487-492, nov.-dic. 2020. ilus, tab, graf
Artigo em Espanhol | IBECS | ID: ibc-200116

RESUMO

INTRODUCCIÓN: El traumatismo craneoencefálico (TCE) constituye un motivo frecuente de consulta en urgencias pediátricas. La necesidad de intervención quirúrgica en pacientes menores de 2 años con TCE leve es mínima, pero los hallazgos intracraneales pueden influir en el manejo del paciente. El objetivo de este trabajo es valorar el impacto de la TC en el manejo de los niños menores de 2 años con TCE leve que presentan una fractura lineal de cráneo en la radiografía convencional. MATERIAL Y MÉTODOS: Estudio descriptivo y retrospectivo en el que se analizan las radiografías de cráneo practicadas a pacientes menores de 2 años que fueron atendidos en el área de urgencias de nuestro hospital de nivel terciario por TCE leve en un período de 4 años. RESULTADOS: Se realizaron 88 exploraciones de tomografía computarizada (TC) realizadas por sospecha de fractura lineal de cráneo en radiografía. Se confirmó la fractura en 74 de ellos (16% de falsos positivos). De los 74 niños con diagnóstico confirmado de fractura, la TC fue normal en el 92% de los estudios y mostró hallazgos intracraneales en 6 casos (8% de los casos con fractura). Dos casos requirieron ingreso superior a 2 días (2,7% de todos los casos con fractura) y en los 4 casos restantes la estancia hospitalaria no superó las 48 horas. En ningún caso se requirió cirugía. CONCLUSIÓN: No parece justificada la realización de una TC craneal de forma sistemática en niños menores de 2 años con TCE y bajo/intermedio riesgo de lesión intracraneal, incluso con fractura lineal de cráneo. En ausencia de factores de riesgo, proponemos individualizar el estudio de imagen basándose en el criterio clínico


INTRODUCTION: Traumatic brain injury (TBI) is a common reason for pediatric emergency room visits. Surgical intervention for mild TBI is rarely necessary in children aged <2 years, but the intracranial findings can influence the management of the patient. This paper aims to evaluate the impact of computed tomography (CT) in the management of children aged <2 years with mild TBI and linear skull fractures on plain-film X-rays. MATERIAL AND METHODS: This retrospective descriptive study analyzed skull X-rays obtained in children <2 years old attended for mild TBI in the emergency room of our tertiary hospital over a 4-year period. RESULTS: A total of 88 CT studies were done for suspicion of linear skull fractures on plain-film X-rays. Fractures were confirmed in 74, representing a false-positive rate of 16%. Of the 74 infants with confirmed fractures, intracranial CT findings were normal in 68 (92%) and abnormal in 6 (8%). Two patients (2.7% of all patients with confirmed fractures) required hospital stays longer than 2 days; the other four patients with abnormal intracranial findings were discharged within 48hours of admission. None of the cases required surgery. CONCLUSION: Systematic CT studies do not seem justified for all children aged <2 years with TBI and low/intermediate risk of intracranial lesions, even when they have linear skull fractures. In the absence of risk factors, we propose individualizing the imaging study based on clinical criteria


Assuntos
Humanos , Recém-Nascido , Lactente , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Índices de Gravidade do Trauma , Estudos Retrospectivos
19.
Rev. esp. med. nucl. imagen mol. (Ed. impr.) ; 39(5): 284-291, sept.-oct. 2020. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-198290

RESUMO

OBJETIVO: Valorar la capacidad diagnóstica de la PET/TC con [18F]F-Fluormetilcolina en la recidiva bioquímica del cáncer de próstata (CP) y su impacto terapéutico. MATERIAL Y MÉTODOS: Se incluyeron 108 pacientes, diagnosticados de CP con criterios bioquímicos de recurrencia. Se realizó una PET/TC Colina mediante estudio dinámico de pelvis y estudio de cuerpo entero a los 60min postinyección del trazador. Se ha analizado la relación entre los estudios positivos y el valor del PSA clasificando a los pacientes en tres grupos (<1,2/1,2-2/>2ng/ml); se ha valorado la capacidad diagnóstica respecto a la RM pelviana y el impacto en la decisión terapéutica. RESULTADOS: Se identificó la localización de la recurrencia en 85 de 108 pacientes (78,7%): 34 local, 47 ganglionar pelviana y 58 lesiones a distancia, incluyendo ganglios retroperitoneales, mediastínicos y lesiones en órganos a distancia (hueso y pulmón). Se diagnosticaron segundos tumores en 4 pacientes. No se encontraron diferencias significativas en el porcentaje de estudios positivos dependiendo del tratamiento primario. Los pacientes con PSA>2ng/ml mostraron un porcentaje de detección de enfermedad más alto que los pacientes con un nivel de PSA inferior, con diferencias significativas (p < 0,0001). La PET/TC [18F]F-Colina fue capaz de detectar enfermedad local, no conocida previamente por la RM, en el 29,41% de los pacientes. La PET/TC Colina tuvo impacto en el manejo terapéutico en 67 de 108 pacientes (62%). CONCLUSIONES: La PET/TC [18F]F-Fluormetilcolina es una herramienta útil en la detección de enfermedad locorregional y diseminada del CP tratado con sospecha de recurrencia, proporcionando un cambio de manejo terapéutico en un 62% de los pacientes


OBJECTIVE: To assess the diagnostic capability of PET/CT with [18F]F-Fluoromethylcholine in prostate cancer (PC) with biochemical recurrence and its therapeutic impact. MATERIAL AND METHODS: We included 108 patients, diagnosed with PC with biochemical criteria for recurrence. A PET/CT Choline scan was performed by dynamic pelvic and whole body study at 60min post-tracer injection. The relationship between the positive studies and the PSA value was analysed by classifying patients into three groups (<1.2/1.2-2/>2ng/ml), and the diagnostic capacity was assessed with respect to pelvic MRI and the impact on the therapeutic decision. RESULTS: The location of recurrence was identified in 85 of 108 patients (78.7%): 34 local, 47 pelvic lymph nodes and 58 distant lesions, including retroperitoneal, mediastinal lymph nodes and distant organ lesions (bone and lung). Second tumors were diagnosed in 4 patients. No significant differences were found in the percentage of positive studies depending on primary treatment. Patients with PSA>2ng/ml showed a higher percentage of disease detection than patients with a lower PSA level, with significant differences (p < 0.0001). PET/CT [18F]F-Choline was able to detect local disease, not previously known from MRI, in 29.41% of patients. PET/CT Choline had an impact on therapeutic management in 67 of 108 patients (62%). CONCLUSIONS: PET/CT with [18F]F-Fluoromethylcholine is a useful tool in the detection of locoregional and disseminated disease of PC treated with suspicion of recurrence, providing a change in therapeutic management in 62% of patients


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Neoplasias da Próstata/diagnóstico por imagem , Recidiva Local de Neoplasia/diagnóstico por imagem , Sensibilidade e Especificidade , Fluordesoxiglucose F18/administração & dosagem , Compostos Radiofarmacêuticos/administração & dosagem , Prostatectomia/métodos , Antígeno Prostático Específico/análise , Estudos Prospectivos
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