Thoracic ultrasound for TB diagnosis in adults and children.

Thoracic ultrasound is an appealing alternative to chest radiography for the diagnosis of TB. Based on research experience conducting thoracic ultrasound for adults and children in South Africa, three key considerations for potential scale-up were identified. First, thoracic ultrasound requires a comprehensive training programme for novice users; artificial intelligence may be used to simplify training and interpretation. Second, a robust ultrasound device is needed with good subpleural resolution and a probe suitable for children. Third, comprehensive scanning of the lungs is time-intensive, and shorter scanning protocols may be more feasible in clinical practice

Neurobeachin Regulates Glutamate- and GABA-Receptor Targeting to Synapses via Distinct Pathways

Neurotransmission and synaptic strength depend on expression of post-synaptic receptors on the cell surface. Post-translational modification of receptors, trafficking to the synapse through the secretory pathway, and subsequent insertion into the synapse involves interaction of the receptor with A-kinase anchor proteins (AKAPs) and scaffolding proteins. Neurobeachin (Nbea), a brain specific AKAP, is required for synaptic surface expression of both glutamate and GABA receptors. Here, we investigated the role of Nbea-dependent targeting of postsynaptic receptors by studying Nbea interaction with synapse-associated protein 102 (SAP102/Dlg3) and protein kinase A subunit II (PKA II). A Nbea mutant lacking the PKA binding domain showed a similar distribution as wild-type Nbea in Nbea null neurons and partially restored GABA receptor surface expression. To understand the relevance of Nbea interaction with SAP102, we analysed SAP102 null mutant mice. Nbea levels were reduced by ~80 % in SAP102 null mice, but glutamatergic receptor expression was normal. A single-point mutation in the pleckstrin homology domain of Nbea (E2218R) resulted in loss of binding with SAP102. When expressed in Nbea null neurons, this mutant fully restored GABA receptor surface expression, but not glutamate receptor expression. Our results suggest that the PKA-binding domain is not essential for Nbea’s role in receptor targeting and that Nbea targets glutamate and GABA receptors to the synapse via distinct molecular pathways by interacting with specific effector proteins

The use of a single-crystal iron frame in transient field g-factor measurements

A single-crystal Fe frame has been used as a target backing in a transient field perturbed angutar correlation measurement on 28Si(2~) with the 28Si(c~, a') reaction at Ec~ = 7.50 MeV. Two sides of the frame are parallel to the (1, 0, 0) axis, the direction of easy magnetization, such that the frame could be magnetized with a field of only H = 240 A/m. Beam-bending effects, caused by fringing fields, are therefore negligible, which results in a reduction of measuring time by a factor of four

Medium energy ion scattering analysis of the evolution and annealing of damage and associated dopant redistribution of ultra shallow implants in Si

As junction depths in advanced semiconductor devices move to below 20 nm, the process of disorder evolution during ion implantation at ultra low energies becomes increasingly influenced by the surface. This may also hold for shallow regrowth and dopant redistribution processes during subsequent thermal annealing of the substrate. The investigation of these near-surface processes requires analytical techniques with a depth resolution of≤1 nm. Medium energy ion scattering (MEIS) has the unique capability of simultaneously providing quantitative, high-resolution depth distributions of implant disorder (displaced Si lattice atoms) and of implanted atoms, albeit not of light species. We report here a comparative MEIS investigation into the growth mode of shallow disordered/amorphised layers during≤1 keV B+ and 2.5 keV As+ ion implantation into Si. In both cases the growth of the damage depth profiles differs significantly from the energy deposition function, as it is strongly determined on the one hand by the proximity of the surface acting as a nucleation site for migrating point defects formed during implantation, which results in planar growth of the amorphous layer, and on the other by the dynamic annealing processes operating at room temperature. When such defect recombination processes are inhibited, e.g. for low dose, ultra shallow 200 eV B+ implants, MEIS shows that defect production yields exceeding the Kinchin–Pease model predictions are achieved. For As implants, a correlation is observed between the movement of the As and the depth of the growing, planar amorphous layer. Thermal annealing of As implanted samples at different temperatures and durations leads to solid phase epitaxial regrowth. During regrowth, MEIS shows that there is a close correlation between damage dissolution, the movement of nearly half of the As dopant into substitutional sites and the snowploughing of a fraction of the As in front of the advancing amorphous/crystalline interface leading to the formation of a less than 1 nm wide As pile-up layer trapped under the oxid

New technique for measuring two-dimensional oxidation-enhanced diffusion in silicon at low temperatures

\u3cp\u3eIn this letter, a new high-resolution technique is presented for determining the lateral extent of oxidation-enhanced diffusion (OED). A periodic grid of lines and spacings is used as an oxidation mask. It will be shown that a simple secondary ion mass spectroscopy measurement permits the extraction of parameters in the lateral direction with a resolution which can be as good as 10 nm. The lateral extent of OED is depth dependent, consistent with a physical model of point-defect recombination at the Si/SiO\u3csub\u3e2\u3c/sub\u3e interface.\u3c/p\u3

High resolution medium energy ion scattering (MEIS) analysis for the quantitative depth profiling of ultra thin high-k layers

Ultrathin high-k layers such as hafnium oxide (HfO2) in combination with a subnanometer SiO2 or Hf silicate have emerged as Si compatible gate dielectric materials. Medium energy ion scattering (MEIS) analysis has been carried out on a range of such metal oxide chemical vapor deposition grown HfO2/SiO2 and HfSiOx(60%Hf)/SiO2 gate oxide films of thickness between 1 and 2 nm on Si(100), before and after decoupled plasma nitridation (DPN). The ability of MEIS in combination with energy spectrum simulation to provide quantitative layer information with subnanometer resolution is illustrated and the effect of the DPN process is shown. Excellent agreement on the deduced layer structures and atomic composition with the as grown layer parameters, as well as with those obtained from cross section electron microscopy and other studies, is demonstrated. MEIS analysis of a high-k, metal gate TiN/Al2O3/HfO2/SiO2/Si stack shows the interdiffusion, after thermal treatment, of Hf and Al from the caplayer, inserted to modify the metal gate workfunction

A high-resolution study of two-dimensional oxidation-enhanced diffusion in silicon

\u3cp\u3eA new method for the determination of two-dimensional oxidation-enhanced diffusion (OED) is presented. The resolution of the technique in the lateral direction is ≈ 10 nm. The technique is used to study the influence of the gate reoxidation step on the channel profile of MOSFET's. For boron, it will be shown that the lateral extent of OED depends on the depth. The same technique is used to study segregation of boron during the lateral oxidation of the polysilicon gate.\u3c/p\u3