66 research outputs found

    El trabajo de Laboratorio en PMAR: Conceptos de Solubilidad y Cristalización y Herramientas necesarias para su comprensión

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    Esta memoria abarca dos propuestas didácticas realizadas con el grupo de 2º ESO para la asignatura de Ámbito Científico y Matemático del PMAR del colegio OD Santo Domingo de Silos durante el curso 2019/20. El primer proyecto fue realizado en el laboratorio de forma presencial y el segundo fue realizado durante el Prácticum II de forma no presencial debido al COVID-19. Ambos proyectos consisten en experiencias prácticas, secuenciales en torno a un proyecto científico, incluyendo la generación de hipótesis, la experimentación, el análisis de datos utilizando hojas de cálculo y la reflexión de los resultados; fomentando espacios para la comunicación, las decisiones responsables y la autonomía. Es un trabajo transversal y multidisciplinar, que utiliza una metodología cooperativa y colaborativa, teniendo en cuenta la diversidad natural existente en la clase, los diferentes ritmos de aprendizaje, los conocimientos previos del alumnado y los míos propios.<br /

    Role of CaCO3° neutral pair in calcium carbonate crystallization

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    The molecular structure of the units that get incorporated into the nuclei of the crystalline phase and sustain their growth is a fundamental issue in the pathway from a supersaturated solution to the formation of crystals. Using a fluorescent dye we have recorded the variation of the pH value in time along a gel where CaCl2 and NaHCO3 counter-diffuse to crystallize CaCO3. The same pH–space–time distribution maps were also computationally obtained using a chemical speciation code (phreeqc). Using data arising from this model we investigated the space-time evolution of the activity of the single species (ions and ion pairs) involved in the crystallization process. Our combined results suggest that, whatever the pathway from solution to crystals, the neutral pair CaCO3° is a key species in the CaCO3 precipitation system.European Research Council (European Union’s Seventh Framework Programme (FP7/2007-2013) grant agreement no 340863, and Spanish MINECO grants MAT2014-60533-R and CGL2010-16882 cofounded with FEDERPeer reviewe

    Contact-less, non-resonant and high-frequency ultrasonic technique: Towards a universal tool for plant leaf study

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    Plant-based measurements are recognized as key methods to obtain insightful data in the field. In general, they are labor-intensive and expensive. In this context, Non-Contact Resonant Ultrasonic Spectroscopy technique (NC-RUS) emerged as a powerful alternative that enabled plant water status determination in a non-destructive, non-invasive and rapid way. However, NC-RUS is not applicable to all plant species as it depends on the possibility to excite and sense thickness resonances in the leaves. In this work, we propose and test an ultrasonic technique that can be used in all leaves, regardless of the appearance of thickness resonances. This technique is based on the contactless measurement of through transmitted airborne ultrasonic pulses in the leaves at high-frequencies and in the absence of thickness resonances, to obtain the leaf ultrasonic velocity (vair). It benefits from the facts that: i) at sufficiently high frequencies (typically around 1 MHz) all leaves are non-resonant (so the technique can be applied to both resonant and non-resonant leaves), ii) the use of high-frequencies allows a greater time resolution and a further miniaturization, making possible to apply the technique to small and irregular leaves. Three different signal processing techniques were used to determine the time it takes to the ultrasonic pulse to cross the leaves (time-of-flight) from the measured signals. Two of them operate in time domain: cross-correlation, and edge detection, while the third one makes use of the Fast Fourier Transform (FFT) and operates in the frequency domain: phase-slope. If leaf thickness is also measured, ultrasound velocity can then be worked out. As ultrasound velocity is determined by density and elastic modulus, it is then closely related to water content and turgor pressure. Obtained ultrasound velocities were first validated by comparing them with those obtained by well-established and standard ultrasonic methods: water immersion transmission (vwater) and NC-RUS (vres). The conclusions of this comparison permitted us to propose a novel methodology that combines the three signal processing techniques used to improve robustness and accuracy for the measurement of ultrasound velocity in plant leaves. It is of interest to note that a bias towards higher values of vair compared to vres was observed. This behavior is considered the consequence of the different influence of the leaf layered structure in these two measurements, so this feature can be further used for leaf structure analysis.Publishe

    Origin, Development and Applications of Air-coupled Broadband Ultrasounds for the Study of Tissues and Water Relations in Plant Leaves: A Review

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    This paper reviews the origin, development and use of air-coupled ultrasonic techniques for the study of plant leaf tissues and their water relations. The two techniques proposed so far are included: Non-Contact Resonant Ultrasound Spectroscopy and Non-Resonant Time Domain Transmittance. While both are completely non-invasive, non-destructive and fast, the former has been used to determine water potential, turgor loss point and differential behavior of various leaf tissues, and has been extensively tested for different species, both in vivo and ex vivo in parallel with in-field experiments; while the latter has recently been proposed as a universal technique that can be applied to plant leaves regardless of the possibility of exciting thickness resonances.10.13039/501100004837-Ministerio de Ciencia e Innovación (Grant Number: JC2020- 043487-I) 10.13039/501100000780-European Commission (Grant Number: NextGenerationEU)Publishe

    Diagnostic value of quantitative SPECT/CT in assessing active sacroiliitis in patients with axial spondylarthritis and/or inflammatory low back pain

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    Background. The diagnostic accuracy of bone scintigraphy (BS) increases with SPECT/CT imaging. It would therefore be appropriate to reassess the diagnostic utility of scintigraphy in sacroiliitis with axial spondyloarthritis (SpA). The aim of this study was to compare the diagnostic performance of MRI, SPECT/CT and a combination of both techniques in sacroiliitis, and to evaluate the correlation between quantitative SPECT/CT indices and quantitative MRI inflammatory lesion scores. Methods. Thirty-one patients with active SpA and 22 patients with inflammatory low back pain underwent MRI and SPECT/CT of the sacroiliac joints. The diagnostic accuracy of both techniques was calculated using clinical diagnosis as the gold standard. The correlation between MRI and SPECT/CT was calculated by comparing the SPECT/CT activity indices and the Berlin/SPARCC scoring systems for MRI. Results. The sensitivity and specificity values in quantitative SPECT/CT, taking the sacroiliac/promontory ratio of >1.36 as the cut-off value, were close to those from MRI published in the literature. The combination of both techniques increased sensitivity while maintaining high specificity. There was a moderate correlation between SPECT/CT and MRI total scores. This correlation was improved by using solely the MRI inflammation scores. Conclusion. Quantitative SPECT/CT showed better diagnostic accuracy than planar scintigraphy and showed a moderate correlation with MRI scores in active sacroiliitis. The combination of both tests increased the diagnostic accuracy. Quantitative SPECT/CT could play a relevant role in the diagnosis of active sacroiliitis in patients with high a suspicion of SpA and a negative/inconclusive MRI test or in patients with whom MRI studies cannot be carried out.Fundamento. La precisión diagnóstica de la gammagrafía ósea (GO) aumenta con las imágenes SPECT/TAC haciendo conveniente reevaluar su utilidad diagnóstica en la sacroilitis de la espondiloartritis axial (EA). El objetivo fue comparar el rendimiento diagnóstico de la resonancia magnética (RM), la SPECT/TC y ambas pruebas combinadas, y evaluar la correlación entre los índices cuantitativos de ambas técnicas. Métodos. A 31 pacientes con EA activa y 22 con lumbalgia inflamatoria se les realizó una RM y una SPECT/TC de las articulaciones sacroilíacas y se calculó la precisión diagnóstica de ambas técnicas respecto al diagnóstico clínico. La correlación entre ambas pruebas se calculó comparando los índices de actividad del SPECT/TC con los sistemas de puntuación Berlín y SPARCC de RM. Resultados. Los valores de sensibilidad y especificidad de la SPECT/TC cuantitativa, tomando como punto de corte el cociente sacroilíaca/promontorio >1,36, fueron similares a los publicados para la RM. La combinación de ambas técnicas aumentó la sensibilidad manteniendo una alta especificidad. La correlación entre las escalas totales de RM y SPECT/TC fue moderada y mejoraba al utilizar únicamente las escalas de inflamación. Conclusiones. La SPECT/TC cuantitativa muestra una mejor precisión diagnóstica que la GO planar en la sacroilitis activa y una correlación moderada con las puntuaciones de RM. La combinación de ambas técnicas aumenta la precisión diagnóstica. Por tanto, la SPECT/TAC cuantitativa podría tener un papel relevante en el diagnóstico de sacroilitis en pacientes con alta sospecha de EA y RM negativa/no concluyente o en aquellos pacientes en los que no se pueda realizar una RM

    Genetic and phenotypic characterisation of HIV-associated aggressive B-cell non-Hodgkin lymphomas, which do not occur specifically in this population: diagnostic and prognostic implications

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    The frequency of aggressive subtypes of B-cell non-Hodgkin lymphoma (B-NHL), such as high-grade B-cell lymphomas (HGBL) with MYC and BCL2 and/or BCL6 rearrangement (HGBL-DH/TH) or Burkitt-like lymphoma (BL) with 11q aberration, is not well known in the HIV setting. We aimed to characterise HIV-associated aggressive B-NHL according to the 2017 WHO criteria, and to identify genotypic and phenotypic features with prognostic impact. Seventy-five HIV-associated aggressive B-NHL were studied by immunohistochemistry (CD10, BCL2, BCL6, MUM1, MYC, and CD30), EBV-encoded RNAs (EBERs), and fluorescence in situ hybridisation (FISH) to evaluate the status of the MYC, BCL2, and BCL6 genes and chromosome 11q. The 2017 WHO classification criteria and the Hans algorithm, for the cell-of-origin classification of diffuse large B-cell lymphomas (DLBCL), were applied. In DLBCL cases, the frequencies of MYC and BCL6 rearrangements (14.9 and 27.7%, respectively) were similar to those described in HIV-negative patients, but BCL2 rearrangements were infrequent (4.3%). MYC expression was identified in 23.4% of DLBCL cases, and coexpression of MYC and BCL2 in 13.0%, which was associated with a worse prognosis. As for BL cases, the expression of MUM1 (30.4%) conferred a worse prognosis. Finally, the prevalence of HGBL-DH/TH and BL-like with 11q aberration are reported in the HIV setting. The phenotypic and genotypic characteristics of HIV-associated aggressive B-NHL are similar to those of the general population, except for the low frequency of BCL2 rearrangements in DLBCL. MYC and BCL2 coexpression in DLBCL, and MUM-1 expression in BL, have a negative prognostic impact on HIV-infected individuals.Peer reviewe

    Ibrutinib in Combination With Rituximab for Indolent Clinical Forms of Mantle Cell Lymphoma (IMCL-2015): A Multicenter, Open-Label, Single-Arm, Phase II Trial

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    PURPOSE The need for an individualized management of indolent clinical forms in mantle cell lymphoma (MCL) is increasingly recognized. We hypothesized that a tailored treatment with ibrutinib in combination with rituximab (IR) could obtain significant responses in these patients. METHODS This is a multicenter single-arm, open-label, phase II study with a two-stage design conducted in 12 Spanish GELTAMO sites (ClinicalTrials.gov identifier: NCT02682641). Previously untreated MCL patients with indolent clinical forms defined by the following criteria were eligible: no disease-related symptoms, nonblastoid variants, Ki-67 < 30%, and largest tumor diameter <= 3 cm. Both leukemic non-nodal and nodal subtypes were recruited. Patients received ibrutinib 560 mg once daily and a total of eight doses of rituximab 375 mg/m(2). Ibrutinib could be discontinued after 2 years in the case of sustained undetectable minimal residual disease (MRD). The primary end point was the complete response (CR) rate achieved after 12 cycles according to Lugano criteria. RESULTS Fifty patients with MCL (male 66%; median age 65 years) were enrolled. After 12 cycles of treatment, 42 (84%; 95% CI, 74 to 94) patients had an overall response, including 40 (80%; 95% CI, 69 to 91) with CR. Moreover, undetectable MRD in peripheral blood was achieved in 87% (95% CI, 77 to 97) of cases. At 2 years, 24 of 35 evaluable patients (69%) could discontinue ibrutinib because of undetectable MRD. Four patients had disease progression; three were non-nodal MCL and carried high genomic complexity and TP53 mutations at enrollment. No unexpected toxicity was seen except one patient with severe aplastic anemia. CONCLUSION Frontline IR combination achieves a high rate of CRs and undetectable MRD in indolent clinical forms of MCL. Discontinuation seems appropriate in cases with undetectable MRD, except for TP53-mutated cases
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