295 research outputs found
Abbreviated MR Protocols in Prostate MRI
Prostate MRI is an integral part of the clinical work-up in biopsy-naïve patients with suspected prostate cancer, and its use has been increasing steadily over the last years. To further its general availability and the number of men benefitting from it and to reduce the costs associated with MR, several approaches have been developed to shorten examination times, e.g., by focusing on sequences that provide the most useful information, employing new technological achievements, or improving the workflow in the MR suite. This review highlights these approaches; discusses their implications, advantages, and disadvantages; and serves as a starting point whenever an abbreviated prostate MRI protocol is being considered for implementation in clinical routine
Evaluación de la Vida Útil Postcosecha de Pera (Packham´S Triumph) Mediante Recubrimiento con Cera de Carnauba y Cera de Abeja
El estudio de la aplicación de recubrimientos sobre la pera es muy escaso, por ese motivo la investigación tuvo como objetivo “Evaluar el efecto que tiene la cera de abeja y cera de carnauba sobre la vida útil postcosecha de pera (Packham´s triumph)”, la evaluación se llevó acabo en la Universidad Privada de Tacna, Laboratorio de análisis de productos agroindustriales. Para ello se empleó cera de carnauba y cera abeja. Mediante experimentos previos se formuló tratamientos con cera de abeja (TCA), con cera de carnauba (TCC) y un tratamiento mezcla (TM, “cera de abeja y cera de carnauba”) donde resultó que el recubrimiento con mayor estabilidad fue mezcla de 40 % cera de abeja y 60 % cera de carnauba, para efectos de análisis se identificó los parámetros necesarios a medir, como son los sólidos solubles totales (SST), la acidez titulable, el pH, el peso, el color, el CO2 y la Firmeza. Concluyendo que el tratamiento mezcla (TM, “cera de abeja 40 % y cera de carnauba 60 %”) tuvo mejores resultados, aumentado la vida útil en cinco y seis días adicionales, los datos obtenido a los 17 días de estudio fueron, sólidos solubles totales (11,3 °brix), la acidez titulable (0,0415 %), el pH (4,98), el peso (13,48 %), el color (café verdoso), el CO2 (27352.59 mg. CO2/Kg.h) y la Firmeza (2,54 N).Tesi
Variedades mejoradas de soya para zonas productoras actuales y potenciales de Colombia.
En el artículo podemos encontrar un breve resumen sobre la soya, así mismo el mejoramiento genético de la soya en Colombia como la resistencia a enfermedades, a plagas, al estrés abiótico, al desgrane y al volcamiento, las variedades de soya desarrolladas por Corpoica y la adaptabilidad de las variedades de soya en Colombia en las diferentes regiones por ejemplo Orinoquia y Valle.Soya-Soja- Glycine ma
Respuesta del maíz (Zea mays) a fósforo y potasio en la zona cafetera de Dolores - Tolima
En la zona cafetera del municipio de Dolores, Tolima, se aplicaron tratamientos de fas fósforo y potasio para nutrición de maíz (Zea mays) en dosis de 0, 20 y 40 kg/ha de P205 y K20 respectivamente, con aplicación constante de 70 kg/ha nitrógeno y un testigo absoluto usado por el agricultor de la zona. Se encuentra respuesta significativa a fósforo (P=0.05) y a potasio (P=0.01); el mayor rendimiento físico se obtuvo con la aplicación de 22.83 kg/ha de P205 y el optimo económico con 21.67 kg/ha para una producción de 3847 kg/ha de maíz. El tratamiento 70-20-20 kg/ha de N P K, fue estadìsticamente el mejor, con un rendimiento físico de 4.136 kg/ha y económico con un retorno marginal de 4.37 per each peso invested
in fertilizers: in the control treatment a yield of 1.925 k/h was. The sensitivity analysis showed
that the best dose remains stable, economically, when the price of fertilizers increases up to
20% or when the price of grain decreases in the same proportion, or even it the combination
of the two factors occurs. So it is recommended that a 70-20-20 level of fertilization should be
used in that zone.Maíz-Zea may
Evaluating residual tumor after neoadjuvant chemotherapy for muscle-invasive urothelial bladder cancer: diagnostic performance and outcomes using biparametric vs. multiparametric MRI
BACKGROUND
Neoadjuvant chemotherapy (NAC) before radical cystectomy is standard of care in patients with muscle-invasive bladder cancer (MIBC). Response assessment after NAC is important but suboptimal using CT. We assessed MRI without vs. with intravenous contrast (biparametric [BP] vs. multiparametric [MP]) for identifying residual disease on cystectomy and explored its prognostic role.
METHODS
Consecutive MIBC patients that underwent NAC, MRI, and cystectomy between January 2000-November 2022 were identified. Two radiologists reviewed BP-MRI (T2 + DWI) and MP-MRI (T2 + DWI + DCE) for residual tumor. Diagnostic performances were compared using receiver operating characteristic curve analysis. Kaplan-Meier curves and Cox proportional-hazards models were used to evaluate association with disease-free survival (DFS).
RESULTS
61 patients (36 men and 25 women; median age 65 years, interquartile range 59-72) were included. After NAC, no residual disease was detected on pathology in 19 (31.1%) patients. BP-MRI was more accurate than MP-MRI for detecting residual disease after NAC: area under the curve = 0.75 (95% confidence interval (CI), 0.62-0.85) vs. 0.58 (95% CI, 0.45-0.70; p = 0.043). Sensitivity were identical (65.1%; 95% CI, 49.1-79.0) but specificity was higher in BP-MRI compared with MP-MRI for determining residual disease: 77.8% (95% CI, 52.4-93.6) vs. 38.9% (95% CI, 17.3-64.3), respectively. Positive BP-MRI and residual disease on pathology were both associated with worse DFS: hazard ratio (HR) = 4.01 (95% CI, 1.70-9.46; p = 0.002) and HR = 5.13 (95% CI, 2.66-17.13; p = 0.008), respectively. Concordance between MRI and pathology results was significantly associated with DFS. Concordant positive (MRI+/pathology+) patients showed worse DFS than concordant negative (MRI-/pathology-) patients (HR = 8.75, 95% CI, 2.02-37.82; p = 0.004) and compared to the discordant group (MRI+/pathology- or MRI-/pathology+) with HR = 3.48 (95% CI, 1.39-8.71; p = 0.014).
CONCLUSION
BP-MRI was more accurate than MP-MRI for identifying residual disease after NAC. A negative BP-MRI was associated with better outcomes, providing complementary information to pathological assessment of cystectomy specimens
Sarcomatoid renal cell carcinoma: MRI features and their association with survival.
OBJECTIVE: To evaluate MRI features of sarcomatoid renal cell carcinoma (RCC) and their association with survival.
METHODS: This retrospective single-center study included 59 patients with sarcomatoid RCC who underwent MRI before nephrectomy during July 2003-December 2019. Three radiologists reviewed MRI findings of tumor size, non-enhancing areas, lymphadenopathy, and volume (and percentage) of T2 low signal intensity areas (T2LIA). Clinicopathological factors of age, gender, ethnicity, baseline metastatic status, pathological details (subtype and extent of sarcomatoid differentiation), treatment type, and follow-up were extracted. Survival was estimated using Kaplan-Meier method and Cox proportional-hazards regression model was used to identify factors associated with survival.
RESULTS: Forty-one males and eighteen females (median age 62 years; interquartile range 51-68) were included. T2LIAs were present in 43 (72.9%) patients. At univariate analysis, clinicopathological factors associated with shorter survival were: greater tumor size (> 10 cm; HR [hazard ratio] = 2.44, 95% CI 1.15-5.21; p = 0.02), metastatic lymph nodes (present; HR = 2.10, 95% CI 1.01-4.37; p = 0.04), extent of sarcomatoid differentiation (non-focal; HR = 3.30, 95% CI 1.55-7.01; p 3.2 mL, HR = 4.22, 95% CI 1.92-9.29); p < 0.01). At multivariate analysis, metastatic disease (HR = 6.89, 95% CI 2.79-16.97; p < 0.01), other subtypes (HR = 9.50, 95% CI 2.81-32.13; p < 0.01), and greater volume of T2LIA (HR = 2.51, 95% CI 1.04-6.05; p = 0.04) remained independently associated with worse survival.
CONCLUSION: T2LIAs were present in approximately two thirds of sarcomatoid RCCs. Volume of T2LIA along with clinicopathological factors were associated with survival
A case of Bartter syndrome type I with atypical presentations
Bartter syndrome (BS) is an autosomal recessively inherited rare renal tubular disorder characterized by hypokalemic metabolic alkalosis and hyperreninemic hyperaldosteronism with normal to low blood pressure due to a renal loss of sodium. Genetically, BS is classified into 5 subtypes according to the underlying genetic defects, and BS is clinically categorized into antenatal BS and classical BS according to onset age. BS type I is caused by loss-of-function mutations in the SLC12A1 gene and usually manifests as antenatal BS. This report concerns a male patient with compound heterozygous missense mutations on SLC12A1 (p.C436Y and p.L560P) and atypical clinical and laboratory features. The patient had low urinary sodium and chloride levels without definite metabolic alkalosis until the age of 32 months, which led to confusion between BS and nephrogenic diabetes insipidus (NDI). In addition, the clinical onset of the patient was far beyond the neonatal period. Genetic study eventually led to the diagnosis of BS type I. The low urinary sodium and chloride concentrations may be caused by secondary NDI, and the later onset may suggest the existence of a genotype-phenotype correlation
DNA barcoding of Brazilian sea turtles (Testudines)
Five out of the seven recognized species of sea turtles (Testudines) occur on the Brazilian coast. The Barcode Initiative is an effort to undertake a molecular inventory of Earth biodiversity. Cytochrome Oxidase c subunit I (COI) molecular tags for sea turtle species have not yet been described. In this study, COI sequences for the five species of sea turtles that occur in Brazil were generated. These presented widely divergent haplotypes. All observed values were on the same range as those already described for other animal groups: the overall mean distance was 8.2%, the mean distance between families (Dermochelyidae and Cheloniidae) 11.7%, the mean intraspecific divergence 0.34%, and the mean distance within Cheloniidae 6.4%, this being 19-fold higher than the mean divergence observed within species. We obtained species-specific COI barcode tags that can be used for identifying each of the marine turtle species studied
Análisis estructural considerando interacción suelo - estructura en centro educativo Puente Piedra
En la actual Norma Peruana de Diseño Sismorresistente, las características del suelo de
fundación y su impacto en la respuesta de la estructura se representan en una modificación de
la aceleración en el sitio de la edificación. Dicho factor se magnifica en la medida de la cantidad
de energía remanente después de la disipada por la deformación del suelo debido a un
determinado nivel de sismo. Por lo tanto, el efecto del suelo incide directamente en la
construcción del espectro de diseño. Sin embargo, no se acompaña dicha consideración de las
propiedades del terreno durante el proceso de análisis.
El desarrollo de la investigación y planteamiento de modelos más acertados con el
comportamiento estructural surge con la necesidad de incrementar la confiabilidad de los
resultados acordes a los objetivos de la ingeniería de desempeño y resiliencia. Por tal motivo,
la interacción suelo-estructura es una de las principales líneas de estudio y busca conocer la
modificación del movimiento del sistema de fundación.
En el presente trabajo de investigación se realiza un análisis modal espectral de un pabellón
escolar de dos niveles y una azotea de muros de concreto armado, cimentado sobre un suelo
arcilloso de baja plasticidad (clasificación S2 según Norma E.030). Se pretende validar los
modelos dinámicos de interacción suelo-estructura propuestos en las guías de diseño
sismorresistente ASCE 41-13 y GBDS 2020. Asimismo, se compara los resultados obtenidos
frente a un modelo de base fija en términos de fuerzas y desplazamientos del sistema y los
elementos estructurales, dentro de los lineamientos de la Norma Peruana.
Finalmente, a partir de las comparaciones de cada modelo, se concluye que la flexibilización
de la base genera un estiramiento del periodo, incremento de las derivas, así como problemas
de irregularidad torsional. Asimismo, la incidencia en las fuerzas de diseño tiene una mayor
variabilidad según el tipo de elemento y su ubicación
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