Discontinuous Galerkin integral equation method for light scattering from complex nanoparticle assemblies.

This paper presents a discontinuous Galerkin (DG) integral equation (IE) method for the electromagnetic analysis of arbitrarily-shaped plasmonic assemblies. The use of nonconformal meshes provides improved flexibility for CAD prototyping and tessellation of the input geometry. The formulation can readily address nonconformal multi-material junctions (where three or more material regions meet), allowing to set very different mesh sizes depending on the material properties of the different subsystems. It also enables the use of h-refinement techniques to improve accuracy without burdening the computational cost. The continuity of the equivalent electric and magnetic surface currents across the junction contours is enforced by a combination of boundary conditions and local, weakly imposed, interior penalties within the junction regions. A comprehensive study is made to compare the performance of different IE-DG alternatives applied to plasmonics. The numerical experiments conducted validate the accuracy and versatility of this formulation for the resolution of complex nanoparticle assemblies.

Metazoan Parasite Communities of Three Endemic Cichlid Fish Species from the Upper Grijalva River, Chiapas, Mexico.

We recorded the metazoan parasite communities in three endemic cichlids (Chiapaheros grammodes, Vieja breidohri and V. hartwegi) collected between November 2008 and July 2009 in the upper Grijalva River Basin (GRB), Chiapas, Mexico. In total, 6,287 individual parasites belonging to 18 taxa (1 monogenean, 6 digeneans, 1 cestode, 4 nematodes, 2 acanthocephalans, 1 hirudinean, 2 copepods and 1 pentastomid) were found. Eleven metazoans were adult forms and 7 larvae; moreover, 14 were endoparasites and 4 ectoparasites. Sixteen parasite taxa represent new geographical and host records. The helminth community in the three cichlids was characterized by higher number of generalists than specialists, as well as a higher proportion of autogenics than allogenics. The metazoan parasites showed prevalence and mean abundances moderate to high. The infracommunities and component community of metazoan parasites had low diversity, richness, and number of individuals and are similar to those reported for other cichlids in Southeastern Mexico, characterized by the presence of typical parasites of cichlids, with a high number of digeneans and generalist parasites. We report the introduced Asian parasitic copepod Neoergasilus japonicus parasitizing endangered or threatened endemic cichlids in the upper GRB. This copepod have been widespread in other freshwater fish species, mainly in Asia (China, India, Japan, Russia, Taiwan), Europe (France, Hungary, Italy, Turkey), and America (Cuba, Mexico, Peru, United States).

Amyloid PET in neurodegenerative diseases with dementia. / PET amiloide en enfermedades neurodegenerativas que cursan con demencia.

Alzheimer's disease (AD) is a neurodegenerative condition characterized by progressive cognitive decline and memory loss, and is the most common form of dementia. Amyloid plaques with neurofibrillary tangles are a neuropathological hallmark of AD that produces synaptic dysfunction and culminates later in neuronal loss. Amyloid PET is a useful, available and non-invasive technique that provides in vivo information about the cortical amyloid burden. In the latest revised criteria for the diagnosis of AD biomarkers were defined and integrated: pathological and diagnostic biomarkers (increased retention on fibrillar amyloid PET or decreased Aß1-42 and increased T-Tau or P-Tau in CSF) and neurodegeneration or topographical biomarkers (temporoparietal hypometabolism on 18F-FDG PET and temporal atrophy on MRI). Recently specific recommendations have been created as a consensus statement on the appropriate use of the imaging biomarkers, including amyloid PET: early-onset cognitive impairment/dementia, atypical forms of AD, mild cognitive impairment with early age of onset, and to differentiate between AD and other neurodegenerative diseases that occur with dementia. Amyloid PET is also contributing to the development of new therapies for AD, as well as in research studies for the study of other neurodegenerative diseases that occur with dementia where the deposition of Aß amyloid is involved in its pathogenesis. In this paper, we review some general concepts and study the use of amyloid PET in depth and its relationship with neurodegenerative diseases and other diagnostic techniques.

Acute sialadenitis as adverse reaction to iodinated contrast. / Sialoadenitis aguda bilateral como reacción adversa a contraste yodado.

Swelling of the salivary glands after administration of iodinated contrast is a very rare adverse reaction. Its etiology is not clear and although it has a benign course associated complications have been reported. We report two cases of acute bilateral sialadenitis after intravenous iodinated contrast in 60 and 63 year-old men who underwent a computed tomography scan in the previous days.

A new era for Nuclear Medicine neuroimaging in Spain: Where do we start from in Spain? / Nuevos tiempos para la neuroimagen de Medicina Nuclear en España: ¿de dónde partimos?

OBJECTIVE: To determine the status of neuroimaging studies of Nuclear Medicine in Spain during 2013 and first quarter of 2014, in order to define the activities of the neuroimaging group of the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM). MATERIAL AND METHODS: A questionnaire of 14 questions was designed, divided into 3 parts: characteristics of the departments (equipment and professionals involved); type of scans and clinical indications; and evaluation methods. The questionnaire was sent to 166 Nuclear Medicine departments. RESULTS: A total of 54 departments distributed among all regions completed the questionnaire. Most departments performed between 300 and 800 neuroimaging examinations per year, representing more than 25 scans per month. The average pieces of equipment were three; half of the departments had a PET/CT scanner and SPECT/CT equipment. Scans performed more frequently were brain SPECT with 123I-FP-CIT, followed by brain perfusion SPECT and PET with 18F-FDG. The most frequent clinical indications were cognitive impairment followed by movement disorders. For evaluation of the images most sites used only visual assessment, and for the quantitative assessment the most used was quantification by region of interest. CONCLUSIONS: These results reflect the clinical activity of 2013 and first quarter of 2014. The main indications of the studies were cognitive impairment and movement disorders. Variability in the evaluation of the studies is among the challenges that will be faced in the coming years.

[Gastric adenomyoma clinically simulating hypertrophic pyloric stenosis]. / Adenomioma gástrico que simula clínicamente una estenosis hipertrófica de píloro.

Gastric adenomyomas are extremely uncommon benign tumors in children. On histologic examination, these tumors have an epithelial component similar to pancreatic ducts. We present a case of a pyloric adenomyoma that clinically simulated hypertrophic pyloric stenosis in a newborn girl. Imaging tests, fundamentally magnetic resonance imaging, were very important in the characterization and diagnosis of this entity.

Machine learning models for the differential diagnosis of vascular parkinsonism and Parkinson's disease using [(123)I]FP-CIT SPECT.

PURPOSE: The study's objective was to develop diagnostic predictive models using data from two commonly used [(123)I]FP-CIT SPECT assessment methods: region-of-interest (ROI) analysis and whole-brain voxel-based analysis. METHODS: We included retrospectively 80 patients with vascular parkinsonism (VP) and 164 patients with Parkinson's disease (PD) who underwent [(123)I]FP-CIT SPECT. Nuclear-medicine specialists evaluated the scans and calculated bilateral caudate and putamen [(123)I]FP-CIT uptake and asymmetry indices using BRASS software. Statistical parametric mapping (SPM) was used to compare the radioligand uptake between the two diseases at the voxel level. Quantitative data from these two methods, together with potential confounding factors for dopamine transporter availability (sex, age, disease duration and severity), were used to build predictive models following a tenfold cross-validation scheme. The performance of logistic regression (LR), linear discriminant analysis and support vector machine (SVM) algorithms for ROI data, and their penalized versions for SPM data (penalized LR, penalized discriminant analysis and SVM), were assessed. RESULTS: Significant differences were found in the ROI analysis after covariate correction between VP and PD patients in [(123)I]FP-CIT uptake in the more affected side of the putamen and the ipsilateral caudate. Age, disease duration and severity were also found to be informative in feeding the statistical model. SPM localized significant reductions in [(123)I]FP-CIT uptake in PD with respect to VP in two specular clusters comprising areas corresponding to the left and right striatum. The diagnostic predictive accuracy of the LR model using ROI data was 90.3 % and of the SVM model using SPM data was 90.4 %. CONCLUSION: The predictive models built with ROI data and SPM data from [(123)I]FP-CIT SPECT provide great discrimination accuracy between VP and PD. External validation of these methods is necessary to confirm their applicability across centres.

[Effectiveness of a school-based program to prevent obesity]. / Efectividad de una intervención escolar contra la obesidad.

INTRODUCTION: Intervention for childhood obesity is a public health priority. The purpose of this study was to evaluate the effectiveness of an elementary school-based intervention against obesity in children. MATERIAL AND METHODS: Non-randomised controlled trial was conducted on children from first to fifth grade from two public schools of Avilés (Spain). The intervention lasted for 2 school years comprising healthy diet workshops, educational chats, educational meetings, informative written material, and promotion of physical activities. Primary outcome measure was body mass index z-score. Secondary outcomes included: obesity and overweight prevalence, waist circumference, dietary habits, and physical activity. RESULTS: A total of 382 (177 girls, 205 boys) out of 526 pupils of both schools were included in the study. Complete anthropometric data were obtained in 340 of the 382 individuals. Compared to children in control group, those in intervention group decreased body mass index z-score from 1.14 to 1.02 (P=.017), and improved KIDMED score from 7.33 to 7.71 points (P=.045). The percentage of students who carried on an optimal diet increased from 42.6% to 52.3% (P=.021). There were no statistical differences in the prevalence of obesity and overweight, or in waist circumference between the intervention and control groups. CONCLUSIONS: This school-based program resulted in modest beneficial changes in body mass index and diet quality.

[Functional neuroimaging in the diagnosis of patients with Parkinsonism: Update and recommendations for clinical use]. / Neuroimagen funcional en el diagnóstico de pacientes con síndrome parkinsoniano: actualización y recomendaciones para el uso clínico.

Functional Neuroimaging has been traditionally used in research for patients with different Parkinsonian syndromes. However, the emergence of commercial radiotracers together with the availability of single photon emission computed tomography (SPECT) and, more recently, positron emission tomography (PET) have made them available for clinical practice. Particularly, the development of clinical evidence achieved by functional neuroimaging techniques over the past two decades have motivated a progressive inclusion of several biomarkers in the clinical diagnostic criteria for neurodegenerative diseases that occur with Parkinsonism. However, the wide range of radiotracers designed to assess the involvement of different pathways in the neurodegenerative process underlying Parkinsonian syndromes (dopaminergic nigrostriatal pathway integrity, basal ganglia and cortical neuronal activity, myocardial sympathetic innervation), and the different neuroimaging techniques currently available (scintigraphy, SPECT and PET), have generated some controversy concerning the best neuroimaging test that should be indicated for the differential diagnosis of Parkinsonism. In this article, a panel of nuclear medicine and neurology experts has evaluated the functional neuroimaging techniques emphazising practical considerations related to the diagnosis of patients with uncertain origin parkinsonism and the assessment Parkinson's disease progression.

[Utility of single photon emission computed tomography-computed tomography in selective sentinel lymph node biopsy in patients with melanoma]. / Utilidad de la tomografía de emisión de fotón único-tomografía computarizada en la biopsia selectiva del ganglio centinela en pacientes con melanoma.

OBJECTIVE: To assess the contribution of SPECT-CT lymphoscintigraphy in selective sentinel lymph node biopsy (SLNB) in patients with newly diagnosed malignant melanoma. MATERIAL AND METHODS: A prospective study was made between July 2009 and October 2010. It included 63 patients diagnosed with melanoma (32 men and 31 women) with mean age of 55 years (range: 25-88) and inclusion criteria for SLNB. The melanomas were located as follows: 28 in trunk, 5 in head and neck, 16 in upper limbs and 17 in lower limbs. Three patients had two melanomas. Preoperative lymphoscintigraphy was performed after pericicatricial/perilesional injection of 74MBq of (99m)Tc-labeled nanocolloid human serum albumin, obtaining early planar images, late whole body study and sectorial images and SPECT-CT in the area of interest. Planar scintigraphy findings were compared with SPECT-CT. RESULTS: The sentinel node (SN) was localized by planar imaging in 62/63 (98%) of patients. SPECT-CT study located the SN in all the patients with a detection rate of 100%. The number of SNs detected with SPECT-CT was higher than with the planar study in 27 patients. The SPECT-CT provided additional information (change in location and/or in its accuracy in the localization of location uncertain SN) in 14/63 (22.2%) patients, involving changes in the surgical approach and lymph node staging. CONCLUSION: SPECT-CT detects a higher number of SN than planar lymphoscintigraphy in patients with melanoma. Its contribution is more relevant in the melanomas located on the trunk, head and neck. SPECT-CT modified the SN location by 22% compared to planar scan findings, facilitating a correct surgical approach.

Directive antenna nanocoupler to plasmonic gap waveguides.

Optical nanocouplers matching a fiber microwaveguide to a plasmonic nanowaveguide are essential components for practical applications of nanophotonic systems. In this Letter we design an efficient nanocoupler using a directive nanoantenna in the visible range λ0=0.65 µm. The antenna has been optimized both in the configuration and in the matching element in order to achieve the maximum coupling efficiency (CE). In spite of the reduced size of the nanoantenna in comparison with the impinging fiber spot size (due to the localized plasmonic resonance at such high frequency), we have shown that a good efficiency can be achieved, improving the CE by a factor of 10 with respect to the nondirective antenna nanocouplers.

[Oral rush desensitization for cow milk allergy: Clinical and immunological follow-up]. / Eficacia y seguridad de una pauta rush de inducción de tolerancia oral en pacientes con alergia a proteínas de leche de vaca: evolución clínica e inmunológica.

OBJECTIVE: The aim of this study was to evaluate the safety and efficacy of oral rush desensitization in children with cow milk allergy. MATERIAL AND METHODS: Prospective study. We included IgE-mediated cow milk allergy children over 3 years in 3 Spanish hospitals. Increasing doses of cow milk for 5 days from 1 cc of 1% to 200 cc of pure milk were administered. Clinical follow-up was conducted and we compared specific IgE levels at onset, 6, 12 and 24 months after desensitization. RESULTS: We included 18 children (13 males) between 3 and 14 years (mean 5.96). A total of 271 doses were administered; there were 55 adverse reactions (84% mild). At the end of the protocol, 100% showed some degree of tolerance (39% total). Full tolerance was achieved in 72% of patients after two years. Two children failed to achieve tolerance. There was a significant decrease in the levels of specific IgE to cow milk and alpha-lactalbumin at 24 months, and to casein at 6, 12 and 24 months, compared to baseline. CONCLUSIONS: Oral rush desensitization is a safe and effective therapeutic option for patients with persistent cow milk allergy to medium term.

[Elaboration of the SPM template for the standardization of SPECT images with 123I-Ioflupane]. / Elaboración de una plantilla de SPM para la normalización de imágenes de SPECT con 123I-Ioflupano.

PURPOSE: Statistical parametric mapping (SPM) is a widely used produced for normalization of functional images. This study has aimed to develop a normalization template of (123)I-Ioflupane SPECT-imaging DaTSCAN(®), GE Healthcare), not available in SPM5, and to validate it compared to other quantification methods. MATERIAL AND METHODS: In order to write the template we retrospectively selected 26 subjects who had no evidence of nigrostriatal degeneration and whose age distribution was similar to that of the patients in the usual practice of our Department: 2 subjects (7.6%) were < 35 years, 9 between 35-65 years (34.6%) and 15 > 65 years (57.7%). All the studies were normalized with the T1-template available in SPM5 and an average image of the value was obtained for each voxel. For validation we analyzed 60 patients: 30 with idiopathic Parkinson's disease patients (iPD) with right involvement (66.83±12.20 years) and 30 with essential tremor patients (ET) (67.27±8.33 years). Specific uptake rates (SUR) of different striatal regions were compared after image normalization with our template and the application of a semiautomated VOIs-map created with Analyze v9.0 ((©)BIR, Mayo Clinic), against two quantification methods: a) manual adjustment of a ROIs-map drawn in Analyze, and b) semi-automated method (HERMES-BRASS) with normalization and implementation of VOIs-map. RESULTS: No statistically significant differences in the iPD/ET discriminatory capacity between the three methods analyzed were observed (p<0,001). The correlation of SUR after normalization with our «template¼ was higher than that obtained by method b) (R>0,871, p<0,001). This difference was greater in patients with PD. CONCLUSIONS: Our study demonstrates the efficacy of our SPM «template¼ for (123)I-Ioflupane SPECT-imaging, obtained from normalization with «T1-template¼.

Comparison of surface integral equation formulations for electromagnetic analysis of plasmonic nanoscatterers.

The performance of most widespread surface integral equation (SIE) formulations with the method of moments (MoM) are studied in the context of plasmonic materials. Although not yet widespread in optics, SIE-MoM approaches bring important advantages for the rigorous analysis of penetrable plasmonic bodies. Criteria such as accuracy in near and far field calculations, iterative convergence and reliability are addressed to assess the suitability of these formulations in the field of plasmonics.