Chemical sensors and biosensors in liquid environment based on microcantilevers with amplified quality factors

Póster presentado al 1st Senspol Workshop: SENSPOL European Thematic Network (EC Environmental and Climate Programma) Sensing Technologies for Contaminated Sites and Groundwater celebrado en Alcala de Henares (Madrid-España) en 2001.Peer reviewe

Microwave-driven synthesis of bisphosphonate nanoparticles allows in vivo visualisation of atherosclerotic plaque

A fast and reproducible microwave-driven process has allowed us to synthesise neridronate-functionalised nanoparticles. Contrary to tradition, the phosphate groups decorate the outside layer of the particles providing Ca2+ binding properties in vitro and selective accumulation in vivo in the atheroma plaque. In vivo and ex vivo detection by T2-weighted MRI is demonstrated and validated by histology. The accumulation in the plaque takes place in less than one hour following the intravenous injection, which is particularly suitable for clinical applications

Lab-on-a-chip platforms based on highly sensitive nanophotonic Si biosensors for single nucleotide DNA testing

In order to solve the drawbacks of sensitivity and portability in optical biosensors we have developed ultrasensitive and miniaturized photonic silicon sensors able to be integrated in a "lab-on-a-chip" microsystem platform. The sensors are integrated Mach-Zehnder interferometers based on TIR optical waveguides (Si/SiO2/Si3N4) of micro/nanodimensions. We have applied this biosensor for DNA testing and for detection of single nucleotide polymorphisms at BRCA-1 gene, involved in breast cancer development, without target labeling. The oligonucleotide probe is immobilized by covalent attachment to the sensor surface through silanization procedures. The hybridization was performed for different DNA target concentrations showing a lowest detection limit at 10 pM. Additionally, we have detected the hybridization of different concentrations of DNA target with two mismatching bases corresponding to a mutation of the BRCA-1 gene. Following the way of the lab-on-a-chip microsystem, integration with the microfluidics has been achieved by using a novel fabrication method of 3-D embedded microchannels using the polymer SU-8 as structural material. The optofluidic chip shows good performances for biosensing

Phase profile analysis of transparent objects through the use of a two windows interferometer based on a one beam splitter configuration

AbstractIn this research we implemented a two windows interferometer based on polarization phase shifting and grating interferometry techniques in order to retrieve the phase data profile of the object in a single capture. The optical configuration has two optical beams with circular polarization in opposite directions, and it is coupled with a 4-f system. An amplitude grid is used as a filter which is placed at the Fourier plane to obtain replicas of each beam which can properly interfere, depending on the separation between beams. The interferometer presents the capability of changing the beam separation in order to make different orders interfere properly. The interference patterns produced can be separately modulated through the operation of linear polarizer's placed on each interference replica. In order to present the capabilities of the system we will select four interferograms result of contiguous orders interference

Paediatric Barcelona Olfactory Test-6 (pBOT-6): Validation of a Combined Odour Identification and Threshold Screening Test in Healthy Spanish Children and Adolescents

Background: Few odour tests have been created for children. Objectives: The aim of the present study was to develop and validate a simple and quick olfactory test, suitable for the evaluation of odour identification and threshold in a Spanish paediatric population, the paediatric Barcelona Olfactory Test-6 (pBOT-6).The pBOT-6 consisted in a set of 6 odorants for a forced-choice identification test (IT), and a 6 dilutions phenyl ethyl alcohol geometric series for the threshold test (TT). The pBOT-6 was compared with the U-sniff test (a validated international paediatric smell test) in 131 Spanish healthy volunteers aged 6-17 years. A Bland-Altman plot was used to determine the agreement between two tests. Reliability was analyzed in fifteenvolunteers using the intraclass correlation coefficient (ICC). Normative data was obtained and 8 children diagnosed with subjective smell loss were tested for validation.Bland-Altman analysis demonstrated a minimal bias of -1.71% with upper and lower limit of agreement of -31.1% and 27.6%, respectively. The ICC was 0.83 (95% CI 0.6-0.96) for the IT and 0.73 (95% CI 0.36-0.9) for the TT, showing excellent and good consistency between measurements over time. Mean pBOT-6 scores were significantly higher in healthy volunteers compared with patients with smell loss. Discrimination between normosmia and smell loss was achieved with a sensitivity of 96.9% and a specificity of 100%.The pBOT-6 offers an effectiveand fast method useful in clinical routine to distinguish, with high sensitivity and specificity, between paediatric patients with normosmia and those with smell dysfunction

Genetic Analysis of Arrhythmogenic Diseases in the Era of NGS: The Complexity of Clinical Decision-Making in Brugada Syndrome

BACKGROUND: The use of next-generation sequencing enables a rapid analysis of many genes associated with sudden cardiac death in diseases like Brugada Syndrome. Genetic variation is identified and associated with 30-35% of cases of Brugada Syndrome, with nearly 20-25% attributable to variants in SCN5A, meaning many cases remain undiagnosed genetically. To evaluate the role of genetic variants in arrhythmogenic diseases and the utility of next-generation sequencing, we applied this technology to resequence 28 main genes associated with arrhythmogenic disorders. MATERIALS AND METHODS: A cohort of 45 clinically diagnosed Brugada Syndrome patients classified as SCN5A-negative was analyzed using next generation sequencing. Twenty-eight genes were resequenced: AKAP9, ANK2, CACNA1C, CACNB2, CASQ2, CAV3, DSC2, DSG2, DSP, GPD1L, HCN4, JUP, KCNE1, KCNE2, KCNE3, KCNH2, KCNJ2, KCNJ5, KCNQ1, NOS1AP, PKP2, RYR2, SCN1B, SCN3B, SCN4B, SCN5A, SNTA1, and TMEM43. A total of 85 clinically evaluated relatives were also genetically analyzed to ascertain familial segregation. RESULTS AND DISCUSSION: Twenty-two patients carried 30 rare genetic variants in 12 genes, only 4 of which were previously associated with Brugada Syndrome. Neither insertion/deletion nor copy number variation were detected. We identified genetic variants in novel candidate genes potentially associated to Brugada Syndrome. These include: 4 genetic variations in AKAP9 including a de novo genetic variation in 3 positive cases; 5 genetic variations in ANK2 detected in 4 cases; variations in KCNJ2 together with CASQ2 in 1 case; genetic variations in RYR2, including a de novo genetic variation and desmosomal proteins encoding genes including DSG2, DSP and JUP, detected in 3 of the cases. Larger gene panels or whole exome sequencing should be considered to identify novel genes associated to Brugada Syndrome. However, application of approaches such as whole exome sequencing would difficult the interpretation for clinical purposes due to the large amount of data generated. The identification of these genetic variants opens new perspectives on the implications of genetic background in the arrhythmogenic substrate for research purposes. CONCLUSIONS: As a paradigm for other arrhythmogenic diseases and for unexplained sudden death, our data show that clinical genetic diagnosis is justified in a family perspective for confirmation of genetic causality. In the era of personalized medicine using high-throughput tools, clinical decision-making is increasingly complex