RF communication with implantable wireless device: effects of beating heart on performance of miniature antenna

The frequency response of an implantable antenna is key to the performance of a wireless implantable sensor. If the antenna detunes significantly, there are substantial power losses resulting in loss of accuracy. One reason for detuning is because of a change in the surrounding environment of an antenna. The pulsating anatomy of the human heart constitutes such a changing environment, so detuning is expected but this has not been quantified dynamically before. Four miniature implantable antennas are presented (two different geometries) along with which are placed within the heart of living swine the dynamic reflection coefficients. These antennas are designed to operate in the short range devices frequency band (863-870 MHz) and are compatible with a deeply implanted cardiovascular pressure sensor. The measurements recorded over 27 seconds capture the effects of the beating heart on the frequency tuning of the implantable antennas. When looked at in the time domain, these effects are clearly physiological and a combination of numerical study and posthumous autopsy proves this to be the case, while retrospective simulation confirms this hypothesis. The impact of pulsating anatomy on antenna design and the need for wideband implantable antennas is highlighted

Measurements of I/SVOCs in biomass-burning smoke using solid-phase extraction disks and two-dimensional gas chromatography

Biomass-burning organic-aerosol (OA) emissions are known to exhibit semi-volatile behavior that impacts OA loading during plume transport. Because such semi-volatile behavior depends in part on OA composition, improved speciation of intermediate and semi-volatile organic compounds (I/SVOCs) emitted during fires is needed to assess the competing effects of primary OA volatilization and secondary OA production. In this study, 18 laboratory fires were sampled in which a range of fuel types were burned. Emitted I/SVOCs were collected onto Teflon filters and solid-phase extraction (SPE) disks to qualitatively characterize particulate and gaseous I/SVOCs, respectively. Derivatized filter extracts were analyzed using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS). Quality control tests were performed using biomass-burning relevant standards and demonstrate the utility of SPE disks for untargeted analysis of air samples. The observed chromatographic profiles of I/SVOCs in coniferous fuel-derived smoke samples were well correlated with each other, but poorly correlated with other fuel types (e.g., herbaceous and chaparral fuels). Emissions of benzenediol isomers were also shown to be fuel dependent. The combined Teflon and SPE filter data captured differences in gas-particle partitioning of the benzenediol isomers, with hydroquinone having a significantly higher particle-phase fraction than catechol due to its lower volatility. Additionally, the speciated volatility distribution of I/SVOCs in smoke from a rotten-log fire was estimated to evaluate the composition of potentially volatilized primary OA, which was entirely attributed to oxygenated (or other heteroatomic) compounds. The isomer-dependent partitioning and the speciated volatility distributions both suggest the need for better understanding of gas-phase and heterogenous reaction pathways of biomass-burning-derived I/SVOCs in order to represent the atmospheric chemistry of smoke in models

The air-liquid flow in a microfluidic airway tree

This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.Microfluidic techniques are employed to investigate air-liquid flows in the pulmonary airway tree. A network of microchannels with five generations is made and used as a simplified model of the pulmonary airway tree. Liquid plugs are injected into the network and pushed by air flow to divide at every bifurcation before reaching the exits. The resistance associated with the presence of one plug in a given generation is defined to establish a linear relation between the driving pressure and the total flow rate in the network. Based on this resistance, we have good predictions of the flow of two successive plugs in the network. For two-plug flows under the same driving pressure, the total flow rate depends not only on the lengths of the plugs but also the initial distance between the two. Strong long range interactions are found between daughter plugs, especially when they are flowing through the bifurcations. We also observe different flow patterns under different pushing conditions. Under a constant pressure forcing, the flow develops symmetrically while a constant flow rate push achieves an asymmetric flow.This study is funded by the ANR under the “Sante-Environnement et Sante-Travail” programme

COMPUTATIONAL STUDY OF BUTYL AND NAPHTHYL AMINE DERIVATIVE OF PERYLENE DIIMIDES TARGETTING TELOMERASE ENZYME FOR ANTICANCER ACTIVITY

Objective: Telomeres are protective caps present at the end of the chromosomes and it contains genetic information. From the literature survey, we selected perylene diimides which interact with the telomerase enzyme and possess anticancer activity. Telomestatin a macrocyclic chemical compound that inhibits telomerase activity as well it induces the formation of G-Quadruplex structures in the telomeric region. The main objective of the study was to find the binding affinity of butyl and naphthyl amine derivative of perylene ligands targeting telomerase enzyme for anticancer activity. Telomerase enzyme is responsible for maintaining the length of telomeres and keeping the chromosomes intact longer. Telomeres will become increasingly common with age. Perylene diimides and its derivatives show good biological activity and also in vitro studies possess efficient anticancer agent. The butyl and naphthyl amine derivatives are screened by computational techniques to study regarding binding energy and ligand interactions with respect to the targets.Methods: Butyl and naphthyl amine derivative of perylene diimides is drawn using Accelrys Draw. The structures are retrieved from the previous study. The structures are converted to pdb formats using Discovery Studio Visualizer 4.1. The study was to investigate the binding energy values of butyl and naphthyl amine derivatives of perylene diimides. Auto Dock 4.2 was used to dock the ligand with the targets. The target selected for docking was 3CE5 and 4B18. The results are visualized by Discovery Studio Visualizer 4.1. The results are compared with the standard drug N,N'-bis-(2-(1- piperidino)ethyl)-3,4,9,10-perylene tetracarboxylic acid diimide (PIPER).Results: From the results, butylamine derivative of perylene diimide possesses good binding energy when compared with standard drug PIPER. This result shows that the butylamine will be effective for anticancer therapy. In future, in vivo studies of butylamine derivative of perylene diimide will be carried out

Neutron Transfer Studied with a Radioactive beam of 24Ne, using TIARA at SPIRAL

A general experimental technique for high resolution studies of nucleon transfer reactions using radioactive beams is briefly described, together with the first new physics results that have been obtained with the new TIARA array. These first results from TIARA are for the reaction 24Ne(d,p)25Ne, studied in inverse kinematics with a pure radioactive beam of 100,000 pps from the SPIRAL facility at GANIL. The reaction probes the energies of neutron orbitals relevant to very neutron rich nuclei in this mass region and the results highlight the emergence of the N=16 magic number for neutrons and the associated disappearance of the N=20 neutron magic number for the very neutron rich neon isotopes.Comment: Proceedings of the Carpathian Summer School of Physics, Mamaia-Constanta, Romania, 13-24 June 200

APPLICATION OF IN SILICO STUDIES TARGETING TELOMERIC G-QUADRUPLEX COMPLEX BY PERYLENE DIIMIDES FOR ANTICANCER THERAPY

Objective: Telomerase enzyme which is expressed in detectable levels and its mechanism was that it increases the length when it binds to telomeres. This eventually leads to extension of lifespan of cells and also makes an attractive target for cancer therapy. Perylene diimides bind to telomerase with duplex genomic DNA, and these G-quadruplex ligands are of responsible for binding affinity with respective proteins. Based on the IC50 values of perylene diimides, QSAR has been studied out and the results are elaborated in preliminary research works. From the results of QSAR, the selected perylene ligands are selected for docking choosing telomerase as a target/protein. From the results of in silico studies, new compounds are designed and synthesized accordingly. Now, the objective of the study was to dock the final synthesized compounds with the telomerase protein to study regarding the pKi value using G-quadruplex ligand database (G4LDB). The docked results are visualized using Discovery Studio Visualizer 4.1. The results are compared with the standard N,N'-bis-(2-(1-piperidino)ethyl)-3,4,9,10-perylene tetracarboxylic acid diimide (PIPER) drug and these compounds will be effective for anticancer therapy.Methods: The study was to investigate the docking results of synthesized perylene compounds with the results from G4LDB and visualized by Discovery Studio 4.1 Visualizer. The telomerase proteins selected for the study were extracted from Protein Data Bank, and the proteins selected for the study are 3SC8 and 3CE5. Among the compounds (R1, R2, R3, and R4) screened in G-Quadruplex Ligand Database, compound R3 shows better binding affinity with good pKi value as well the interactions with the protein and ligand show better affinity with the targets and these are compared with the standard drug PIPER drug.Results: Compound R3 possesses the best binding affinity with the target 3CE5 and 3SC8 which shows that the compound will be effective for anticancer therapy

Approach to the patient: the evaluation and management of men ≥ 50 years with a low serum testosterone concentration

Although testosterone replacement in men with classic hypogonadism due to an identified pathology of the hypothalamic-pituitary-testicular axis is uncontroversial, the role of testosterone treatment for men with age-related declines in circulating testosterone is unclear. This is due to the lack of large, long-term testosterone therapy trials assessing definitive clinical endpoints. However, men >50 years, particularly those who have a body mass index >25 kg/m2 and multiple co-morbidities, commonly present with clinical features of androgen deficiency and low serum testosterone concentrations. Clinicians are faced with the question whether to initiate testosterone therapy, a difficult dilemma that entails a benefit-risk analysis with limited evidence from clinical trials. Using a case scenario, we present a practical approach to the clinical assessment and management of such men

Auditory imagery ability influences accuracy when singing with altered auditory feedback

In this preliminary study, we explored the relationship between auditory imagery ability and the maintenance of tonal and temporal accuracy when singing and audiating with altered auditory feedback (AAF). Actively performing participants sang and audiated (sang mentally but not aloud) a self-selected piece in AAF conditions, including upward pitch-shifts and delayed auditory feedback (DAF), and with speech distraction. Participants with higher self-reported scores on the Bucknell Auditory Imagery Scale (BAIS) produced a tonal reference that was less disrupted by pitch shifts and speech distraction than musicians with lower scores. However, there was no observed effect of BAIS score on temporal deviation when singing with DAF. Auditory imagery ability was not related to the experience of having studied music theory formally, but was significantly related to the experience of performing. The significant effect of auditory imagery ability on tonal reference deviation remained even after partialling out the effect of experience of performing. The results indicate that auditory imagery ability plays a key role in maintaining an internal tonal center during singing but has at most a weak effect on temporal consistency. In this article, we outline future directions in understanding the multifaceted role of auditory imagery ability in singers’ accuracy and expression