Fabrication and modeling of a continuous-flow microfluidic device for on-chip DNA amplification

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.The fabrication process and heat transfer computations for a continuous flow microfluidic device for DNA amplification by polymerase chain reaction (PCR) are described. The building blocks are thin polymeric materials aiming at a low cost and low power consumption device. The fabrication is performed by standard pattern transfer techniques (lithography and etching) used for microelectronics fabrication. The DNA sample flows in a meander shaped microchannel formed on a 100μm thick polyimide (PI) layer through three temperature regions defined by the integrated resistive heaters. The heat transfer computations are performed in a unit cell of the device. They show that, for the fabricated device, the variation of the temperature inside the channel zones where each step (denaturation, annealing, or extension) of PCR occur is less than 1.3K. This variation increases when the thickness of the PI layer increases. The computations also show that similar Silicon-based devices lead to lower temperature difference between the heaters and the DNA sample compared to the polymer-based fabricated device. However, the power consumption is estimated much greater for Silicon-based devices.This work was co-financed by Hellenic Funds and by the European Regional Development Fund (ERDF) under the Hellenic National Strategic Reference Framework (NSRF) 2007-2013, according to Contract no. MICRO2-45 of the Project “Microelectronic Components for Lab-on-chip molecular analysis instruments for genetic and environmental applications” within the Programme "Hellenic Technology Clusters in Microelectronics – Phase-2 Aid Measure"

BRCA1 and BRCA2 mutations in a population-based study of male breast cancer

Background: The contribution of BRCA1 and BRCA2 to the incidence of male breast cancer (MBC) in the United Kingdom is not known, and the importance of these genes in the increased risk of female breast cancer associated with a family history of breast cancer in a male first-degree relative is unclear. Methods: We have carried out a population-based study of 94 MBC cases collected in the UK. We screened genomic DNA for mutations in BRCA1 and BRCA2 and used family history data from these cases to calculate the risk of breast cancer to female relatives of MBC cases. We also estimated the contribution of BRCA1 and BRCA2 to this risk. Results: Nineteen cases (20%) reported a first-degree relative with breast cancer, of whom seven also had an affected second-degree relative. The breast cancer risk in female first-degree relatives was 2.4 times (95% confidence interval [CI] = 1.4–4.0) the risk in the general population. No BRCA1 mutation carriers were identified and five cases were found to carry a mutation in BRCA2. Allowing for a mutation detection sensitivity frequency of 70%, the carrier frequency for BRCA2 mutations was 8% (95% CI = 3–19). All the mutation carriers had a family history of breast, ovarian, prostate or pancreatic cancer. However, BRCA2 accounted for only 15% of the excess familial risk of breast cancer in female first-degree relatives. Conclusion: These data suggest that other genes that confer an increased risk for both female and male breast cancer have yet to be found

Characterization of encapsulation materials for implantable DBS device/Sapiens Steering Brain Stimulation

This report presents the results of the work of one year in Sapiens Steering Brain Stimulation. A general description of the company objective is given and later the project is defined. The project has two main sub-projects: the characterization of the materials to be used as encapsulation for electronics and the mechanical testing of the isolative layers of the thin film, as an essential part of the implantable part of the device. For the first sub-project, the coating parameters are investigated through time experiments of samples exposed in saline. For the second part, samples are put under bending stress and mechanical tolerance is tested. Any mechanical failure or defective coating will have as a consequence an amount of current to leak out of the insulation layers. Both characterization and film testing are realized through leakage current measurements after applying a specific value of voltage. The setup is also validated. For the encapsulation materials, a well-defined process flow is suggested for sample preparation and coating in the clean room, pointing out the significance of cleaning the samples in the efficiency of the coating. Combinations of materials such as parylene and silicone or parylene and PU are tested and evaluated. For the thin film testing, bending test results are compared with theoretical strain calculations and safety specifications. The results of both the sub-projects indicate that leakage current measurement is a reliable method for evaluating the performance of both encapsulation materials and thin film

Liver lobe torsion in a cat with diaphragmatic hernia

A 10-year-old neutered male domestic shorthair cat was referred with a 2-week history of dyspnoea and anorexia following injury in a car accident. Thoracic radiography and ultrasonography revealed a diaphragmatic hernia. A midline coeliotomy revealed a centrally located hernia ventral to the caudal vena cava. Hernia reduction required incision of the hernia ring. Displaced organs included the duodenum; jejunum; ascending and transverse colon; and right, caudate and quadrate liver lobes. After reduction of the abdominal organs, a torsion of the right medial and quadrate liver lobes was identified. Lobectomy was performed followed by herniorrhaphy. The cat had an uneventful recovery and was clinically normal on re-examination 1, 6, 12 and 24 months following the surgery. © 2020 BMJ Publishing Group. All rights reserved