T-1-MRI Fluorescent Iron Oxide Nanoparticles by Microwave Assisted Synthesis

Iron oxide nanoparticles have long been studied as a T-2 contrast agent in MRI due to their superparamagnetic behavior. T-1-based positive contrast, being much more favorable for clinical application due to brighter and more accurate signaling is, however, still limited to gadolinium- or manganese-based imaging tools. Though being the only available commercial positive-contrast agents, they lack an efficient argument when it comes to biological toxicity and their circulatory half-life in blood. The need arises to design a biocompatible contrast agent with a scope for easy surface functionalization for long circulation in blood and/or targeted imaging. We hereby propose an extremely fast microwave synthesis for fluorescein-labeled extremely-small iron oxide nanoparticles (fdIONP), in a single step, as a viable tool for cell labeling and T-1-MRI. We demonstrate the capabilities of such an approach through high-quality magnetic resonance angiographic images of mice.This study was supported by a grant from Ministerio de Economia y Competitividad (MAT2013-47303-P) and European Union (Cardionext, ITN-FP7-608027).S

Mealiness assessment in fruits using MRI techniques.

Mealiness is a sensory attribute that cannot be defined by a single parameter but through a combination of variables (multidimensional structure). Previous studies propose the definition of mealiness as the lack of crispiness, of hardness and of juiciness. Current aims are focused on establishing non destructive tests for mealiness assessment. MultiSliceMultiEcho Magnetic resonance images (MRI, 64*64pixels) have been taken corresponding to a 3ms of Echo time. Small samples of Top Red apples stored 6 months at controlled atmosphere (expected to be non mealy) and 2°C (expected to be mealy) have been used for MRI imaging. Three out of four apples corresponding to the sample maintained at controlled atmosphere did not develop mealiness while three out of four fruits corresponding to the sample stored at 2°C became mealy after 6 month of storage. The minimum T2 values/image obtained for the mealy apples shows to be significantly lower when compared with non mealy apples pointing that a more dis-aggregated structure leads to a quicker loss of signal Also, there is a significant linear correlation (r=-0.76) between the number of pixels with a T2 value below 35ms within a fruit image and the deformation parameter registered during the Magness-Taylor firmness test. Finally, all the T2 images of the mealy apples show a regional variation of contrast which is not shown for non mealy apples. This variation of contrast is similar to the MRI images of water-cored apples indicating that in these cases there is a differential water movement that may precede the internal browning

Modeling for Metabonomic Fingerprint Assignment in Olive Fruits

Metabonomics has been recently applied to a variety of studies in the agri-food field, mainly focused on adulteration identification and cultivar or geographical origin assessment. One-dimensional HR-NMR spectrum was acquired using a standard 1D pulse sequence (NOESYPRESAT) with water peak suppression. Two-dimension correlation spectroscopy analyses, 1H-1H 2D experiments (COSY90), were performed. ACD/LABS 8.00 software package was used to obtain simulated spectra from main components in olive, and minor components including those responsible for antioxidant characteristic and aromatics. The application of multivariate statistical techniques to a large HR-NMR spectra data base is the next ste

A novel R-package graphic user interface for the analysis of metabonomic profiles

Background Analysis of the plethora of metabolites found in the NMR spectra of biological fluids or tissues requires data complexity to be simplified. We present a graphical user interface (GUI) for NMR-based metabonomic analysis. The "Metabonomic Package" has been developed for metabonomics research as open-source software and uses the R statistical libraries. /Results The package offers the following options: Raw 1-dimensional spectra processing: phase, baseline correction and normalization. Importing processed spectra. Including/excluding spectral ranges, optional binning and bucketing, detection and alignment of peaks. Sorting of metabolites based on their ability to discriminate, metabolite selection, and outlier identification. Multivariate unsupervised analysis: principal components analysis (PCA). Multivariate supervised analysis: partial least squares (PLS), linear discriminant analysis (LDA), k-nearest neighbor classification. Neural networks. Visualization and overlapping of spectra. Plot values of the chemical shift position for different samples. Furthermore, the "Metabonomic" GUI includes a console to enable other kinds of analyses and to take advantage of all R statistical tools. /Conclusion We made complex multivariate analysis user-friendly for both experienced and novice users, which could help to expand the use of NMR-based metabonomics

Detection of seeds in citrus using MRI under motion conditions and improvement with motion correction

Magnetic resonance imaging (MRI) is studied under an online strategy. Axial FLASH images (780 ms acquisition time) have been analyzed to identify seed-containing oranges conveyed at 50 and 100 mm/s through a 4.7 Tesla spectrometer. Developed algorithms enable an automated identification of oranges with more than one seed, though axial images under motion conditions suffer from significant blurring artifacts. To overcome this hindrance, coronal FLASH images have been acquired (279 ms acquisition time), developing devoted algorithms for motion correction with encouraging results for quality improvement of dynamic image

MRI texture analysis as means for addressing rehydration and milk diffusion in cereals

Cereals microstructure is one of the primary quality attributes of cereals. Cereals rehydration and milk diffusion depends on such microstructure and thus, the crispiness and the texture, which will make it more palatable for the final consumer. Magnetic Resonance Imaging (MRI) is a very powerful tomographic tool since acquisition parameter leads to a wide possibility for identifying textures, structures and liquids mobility. It is suited for noninvasive imaging of water and fats. Rehydration and diffusion cereals processes were measured by MRI at different times and using two different kinds of milk, varying their fat level. Several images were obtained. A combination of textural analysis (based on the analysis of histograms) and segmentation methods (in order to understand the rehydration level of each variety of cereals) were performed. According to the rehydration level, no advisable clustering behaviour was found. Nevertheless, some differences were noticeable between the coating, the type of milk and the variety of cereals

Corrección de desfase en imágenes de Resonancia Magnética

La imagen de Resonancia Magnética (IRM) se ha estudiado para su aplicación en línea. Se han adquirido dos tipos de imágenes FLASH coronales (tiempo de adquisición 279 ms para limones y 703 para naranjas) de muestras estáticas y conducidas a 54 mm/s a través de un espectrómetro de 4.7 Teslas. Los algoritmos desarrollados para la corrección automática del movimiento has mostrado una mejora notoria en la calidad de las imágenes dinámicas. Las imágenes estáticas y dinámicas corregidas fueron comparadas mediante sus histogramas acumulados loscuales mostraron altos coeficientes de determinación (R2 = 0.96 para limones y 0.98 para naranjas). Un análisis de varianza de los parámetros extraídos de las imágenes estáticas y dinámicas corregidas mostró diferencias no significativas

Mealiness assessment in apples and peaches using MRI techniques.

Since Januarv 1946 a wade EC Project entitled "Mealiness in fruits Consumers perception and means for detection is being carried out. Mealiness is a sensory attribute that cannot be defined by a single parameter but through a combination of variables (multidimensional structure) Previous studies propose the definition of mealiness as the lack of crispiness of hardness and of juiciness. A destructive instrumental procedure combined with a integration technique has been already developed enabling to identify mealy fruits by destructive instrumental means use other contributions of Barreiro and Ortiz to this Ag Eng 98. Current aims .are focused on establishing non destructive tests for mealiness assessment. Magnetic resonance Imaging (MRI) makes use of the magnetic properties that some atomic nuclei have. especially hidrogen nuclei from water molecules to obtain high quality images in the field of internal quality evaluation the MRI has been used to assess internal injury due to conservation as o treatments as chilling injury un Persimmons Clark&Forbes (1994) and water-core in apples (Wang et al. 1998. In the case of persimmons the chilling injury is described as an initial tissue breakdown and lack of cohesion between cells followed by formation of a firm gel and by a lack of juiciness without changes in the total amount ol water content. Also a browning of the flesh is indicated (Clark&Forhes 1994). This definition fits into the previous description of mealiness

From Microscopic to Macroscopic Description of Composite Thin Panels: A Roadmap for their Simulation in Time Domain

In this paper, we show a simulation strategy for composite dispersive thin-panels, starting from their microscopic characteristics and ending into a time-domain macroscopic model. In a first part, we revisit different semianalytic methods that may be used to obtain the S-parameter matrices. The validity of them is assessed with numerical simulations and experimental data. We also include some formulas that may be used to tailor the shielding effectiveness of panels in a design phase. In a second part, we present an extension to dispersive media of a subgridding hybrid implicit–explicit algorithm finite difference time domain (FDTD) devised by the authors to deal with that kind of materials. The method, here presented and applied to the FDTD method, is a robustly stable alternative to classical impedance boundary condition techniques. For this, a previous analytical procedure allowing to extract an equivalent effective media from S-parameters is presented, thus making this road map able to simulate any kind of dispersive thin layer. A numerical validation of the algorithm is finally shown by comparing with experimental data

Assessment of regional pulmonary blood flow using Ga-68-DOTA PET

Background: In vivo determination of regional pulmonary blood flow (PBF) is a valuable tool for the evaluation of many lung diseases. In this study, the use of Ga-68-DOTA PET for the in vivo quantitative determination of regional PBF is proposed. This methodology was implemented and tested in healthy pigs and validated using fluorescent microspheres. The study was performed on young large white pigs (n = 4). To assess the reproducibility and consistency of the method, three PET scans were obtained for each animal. Each radiotracer injection was performed simultaneously to the injection of fluorescent microspheres. PBF images were generated applying a two-compartment exchange model over the dynamic PET images. PET and microspheres values were compared by regression analysis and Bland-Altman plot. Results: The capability of the proposed technique to produce 3D regional PBF images was demonstrated. The correlation evaluation between Ga-68-DOTA PET and microspheres showed a good and significant correlation (r = 0.74, P < 0.001). Conclusions: Assessment of PBF with the proposed technique allows combining the high quantitative accuracy of PET imaging with the use of Ga-68/Ge-68 generators. Thus, Ga-68-DOTA PET emerges as a potential inexpensive method for measuring PBF in clinical settings with an extended use.This work was supported by a grant from the Spanish Ministry of Economy and Competitiveness (MINECO) (SAF2014-58920-R) and a grant from the Carlos III Institute of Health (FIS-FEDER PI14-01427). C. Velasco is a recipient of a fellowship from the Spanish Ministry of Education (FPU014/01794). S. Espana and A. Santos are recipients of M+Vision Advanced fellowships from the community of Madrid. The CNIC is supported by the MINECO and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (MINECO award SEV-2015-0505).S