Miniature electrometer preamplifier effectively compensates for input capacitance

Negative capacitance preamplifier using a dual MOS /Metal Oxide Silicon/ transistor in conjunction with bipolar transistors is used with intracellular microelectrodes in recording bioelectric potentials. Applications would include use as a pickup plate video amplifier in storage tube tests and for pH and ionization chamber measurements

Numerical comparison between Maxwell stress method and equivalent multipole approach for calculation of the dielectrophoretic force in octupolar cell traps

This work presents detailed numerical calculations of the dielectrophoretic force in octupolar traps designed for single-cell trapping. A trap with eight planar electrodes is studied for spherical and ellipsoidal particles using an indirect implementation of the boundary element method (BEM). Multipolar approximations of orders one to three are compared with the full Maxwell stress tensor (MST) calculation of the electrical force on spherical particles. Ellipsoidal particles are also studied, but in their case only the dipolar approximation is available for comparison with the MST solution. The results show that the full MST calculation is only required in the study of non-spherical particles.Singapore-MIT Alliance (SMA

Optical addressing of an individual erbium ion in silicon

The detection of electron spins associated with single defects in solids is a critical operation for a range of quantum information and measurement applications currently under development. To date, it has only been accomplished for two centres in crystalline solids: phosphorus in silicon using electrical readout based on a single electron transistor (SET) and nitrogen-vacancy centres in diamond using optical readout. A spin readout fidelity of about 90% has been demonstrated with both electrical readout and optical readout, however, the thermal limitations of the electrical readout and the poor photon collection efficiency of the optical readout hinder achieving the high fidelity required for quantum information applications. Here we demonstrate a hybrid approach using optical excitation to change the charge state of the defect centre in a silicon-based SET, conditional on its spin state, and then detecting this change electrically. The optical frequency addressing in high spectral resolution conquers the thermal broadening limitation of the previous electrical readout and charge sensing avoids the difficulties of efficient photon collection. This is done with erbium in silicon and has the potential to enable new architectures for quantum information processing devices and to dramatically increase the range of defect centres that can be exploited. Further, the efficient electrical detection of the optical excitation of single sites in silicon is a major step in developing an interconnect between silicon and optical based quantum computing technologies.Comment: Corrected the third affiliation. Corrected one cross-reference of "Fig. 3b" to "Fig. 3c". Corrected the caption of Fig. 3a by changing (+-)1 to

Detection and molecular characterisation of plasmidic AmpC b-lactamases in Klebsiella pneumoniae isolates from a tertiary-care hospital in Dublin, Ireland

This study determined the types of AmpC enzymes produced by Klebsiella pneumoniae isolates resistant to third-generation cephalosporins and the clonality of these isolates. The presence of AmpC enzymes was identified by cephalosporin-cloxacillin synergy tests. Genes encoding AmpC enzymes were characterised by PCR and sequencing. Pulsed-field gel electrophoresis (PFGE) was used to type the isolates. Fifteen K. pneumoniae isolates were positive for bla(AmpC), 13 were positive for bla(ACC-1) and two were positive for bla(DHA-1). Production of the DHA-1 enzyme was inducible. The ampR gene was identified upstream of the bla(DHA-1) gene. PFGE demonstrated the polyclonal origin of the isolates carrying bla(ACC-1)

Glycated platelets proteome

Comunicaciones a congreso

Ethyl Alcohol Extract of Hizikia fusiforme Induces Caspase-dependent Apoptosis in Human Leukemia U937 Cells by Generation of Reactive Oxygen Species

Purpose: Hizikia fusiforme is renowned for the possession of anti-inflammatory and anti-oxidant properties. In this study, the role of the ethyl alcohol extract of H. fusiforme (EAHF) in the induction of apoptosis in human leukemia U937 cells was investigated.Methods: Protein expression was investigated by Western blot analysis. Cell viability and apoptosis were analyzed by an MTT assay and flow cytometric analysis. Caspase activity was analyzed using a caspase-specific kit.Results: EAHF suppressed the proliferation of U937 cells in a dose-dependent manner. This effect was closely related to the induction of apoptosis via the downregulation of IAP family members such as IAP-1, IAP-2 and XIAP, as well as Bcl-2 proteins. The results also showed that caspases play an essential role in EAHF-induced apoptosis by generating of reactive oxygen species (ROS). In addition, ROS scavenging by N-acetyl-L-cysteine (NAC) and glutathione (GSH) decreased EAHF-induced apoptosis via the suppression of caspase activity. Although EAHF induced the phosphorylation of mitogenactivated protein kinases (MAPKs), treatment with MAPK inhibitors did not affect EAHF-induced apoptosis.Conclusion: These results suggest that EAHF induces apoptosis in U937 cells via ROS-dependent caspase activation.Keywords: Hizikia fusiforme, Apoptosis, Caspase, Reactive oxygen specie

Delivering Parenting Interventions through Health Services in the Caribbean

Integrating early childhood interventions with health and nutrition services has been recommended, however there is limited information on interventions that are effective and feasible for delivery through health services. In this trial we developed and evaluated a parenting program that could be integrated into primary health center visits

Single rare-earth ions as atomic-scale probes in ultra-scaled transistors

Continued dimensional scaling of semiconductor devices has driven information technology into vastly diverse applications. As the size of devices approaches fundamental limits, metrology techniques with nanometre resolution and three-dimensional (3D) capabilities are desired for device optimisation. For example, the performance of an ultra-scaled transistor can be strongly influenced by the local electric field and strain. Here we study the spectral response of single erbium ions to applied electric field and strain in a silicon ultra-scaled transistor. Stark shifts induced by both the overall electric field and the local charge environment are observed. Further, changes in strain smaller than $3\times 10^{-6}$ are detected, which is around two orders of magnitude more sensitive than the standard techniques used in the semiconductor industry. These results open new possibilities for non-destructive 3D mapping of the local strain and electric field in the channel of ultra-scaled transistors, using the single erbium ions as ultra-sensitive atomic probes.Comment: 10+5 pages, 4+3 figure