A neglected disease of humans: a new focus of visceral leishmaniasis in Bakool, Somalia.

Visceral leishmaniasis (VL) was observed in children in Bakool region, Somalia, an area where VL has not been reported before. We describe the extent of the problem in this war- and famine-stricken area. A retrospective analysis was done of all cases admitted to a VL treatment centre between July 2000 and August 2001. Patients with longstanding fever, splenomegaly and a positive direct agglutination test (DAT; titre > 1:3200) were treated as suspected VL cases. A rapid epidemiological and entomological assessment was performed in the area. Species identification was attempted from blood samples by polymerase chain reaction-restriction fragment length polymorphism analysis of cysteine proteinase B genes. In 1 year, 230 serologically-positive cases were diagnosed as VL, and response to therapy was good in 91.6% of the 225 treated with sodium stibogluconate. Parasitological confirmation was attempted and obtained in 2 cases. Parasites were found to be most similar to Sudanese and Ethiopian reference strains of the Leishmania donovani complex. In a serological survey of 161 healthy displaced persons, 15% were positive by the leishmanin skin test and 3 (2%) were positive by the DAT. The sandfly captures showed Phlebotomus martini and P. vansomerenae. VL seems to be a longstanding and serious health problem in Bakool region. Food insecurity might have contributed to the emergence and detection of VL in this area

Epitaxial Synthesis of Blue Phosphorene

Phosphorene is a new two-dimensional material composed of a single or few atomic layers of black phosphorus. Phosphorene has both an intrinsic tunable direct band gap and high carrier mobility values, which make it suitable for a large variety of optical and electronic devices. However, the synthesis of single-layer phosphorene is a major challenge. The standard procedure to obtain phosphorene is by exfoliation. More recently, the epitaxial growth of single-layer phosphorene on Au(111) has been investigated by molecular beam epitaxy and the obtained structure has been described as a blue-phosphorene sheet. In the present study, large areas of high-quality monolayer phosphorene, with a band gap value at least equal to 0.8 eV, have been synthesized on Au(111). Our experimental investigations, coupled with DFT calculations, give evidence of two distinct phases of blue phosphorene on Au(111), instead of one as previously reported, and their atomic structures have been determined.Comment: This paper reports on the epitaxial synthesis of blue phosphoren

Conversion of total shoulder arthroplasty to reverse shoulder arthroplasty made possible by custom humeral adapter

AbstractReverse shoulder arthroplasty (RSA) is increasingly being used to revise anatomical total shoulder arthroplasty cases. This procedure's high complication rate has been reduced by the availability of modular shoulder systems, which allows the humeral component to be preserved during the conversion. This case report describes the revision of an anatomical shoulder implant inserted in 1998. Polyethylene wear and the resulting metal-on-metal contact had caused metallosis. Since the existing humeral implant was not compatible with standard conversion products, the manufacturer provided a custom humeral adapter that allowed the humeral stem to be preserved. This approach greatly simplified the surgical procedure and resulted in good anatomical and clinical outcomes after 9 months of follow-up

Fluorescent oxide nanoparticles adapted to active tips for near-field optics

We present a new kind of fluorescent oxide nanoparticles with properties well suited to active-tip based near-field optics. These particles with an average diameter in the range 5-10 nm are produced by Low Energy Cluster Beam Deposition (LECBD) from a YAG:Ce3+ target. They are studied by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), classical photoluminescence, cathodoluminescence and near-field scanning optical microscopy (NSOM). Particles of extreme photo-stability as small as 10 nm in size are observed. These emitters are validated as building blocks of active NSOM tips by coating a standard optical tip with a 10 nm thick layer of YAG:Ce3+ particles directly in the LECBD reactor and by subsequently performing NSOM imaging of test surfaces.Comment: Changes made following Referee's comments; added references; one added figure. See story on this article at: http://nanotechweb.org/cws/article/tech/3606

Quantitative influence of non-hormonal blood factors on the control of sodium excretion by the isolated dog kidney

Quantitative influence of non-hormonal blood factors on the control of sodium excretion by the isolated dog kidney.On the basis of experiments performed on isolated dog kidneys, thus eliminating extrarenal hormonal controls, an attempt has been made to evaluate the influence of arterial blood pressure and several non-hormonal blood parameters on fractional sodium excretion.The roles of plasma protein concentration as modulated by filtration fraction, total renal plasma flow, hematocrit, arterial pressure and plasma potassium concentration on overall fractional sodium reabsorption have been evidenced and quantitatively evaluated.Although the control of sodium reabsorption by renal plasma flow and by hematocrit can be ascribed partly to changes in filtration fraction and post-glomerular plasma protein concentration, other mechanisms appear to be involved as well.Variations in filtration fraction and postglomerular plasma protein concentration play little, if any, role in the induction of pressure natriuresis.The autonomous and quantitative response of the kidney to blood dilution during saline diuresis represents the cumulative results, not only of the dilution of pre- and postglomerular plasma proteins, but also of the simultaneous decrease of hematocrit and increase of renal plasma flow.The implications of these results for the understanding of the adjustment of sodium balance in acute and chronic conditions are discussed

Autocorrelation analysis for the unbiased determination of power-law exponents in single-quantum-dot blinking

We present an unbiased and robust analysis method for power-law blinking statistics in the photoluminescence of single nano-emitters, allowing us to extract both the bright- and dark-state power-law exponents from the emitters' intensity autocorrelation functions. As opposed to the widely-used threshold method, our technique therefore does not require discriminating the emission levels of bright and dark states in the experimental intensity timetraces. We rely on the simultaneous recording of 450 emission timetraces of single CdSe/CdS core/shell quantum dots at a frame rate of 250 Hz with single photon sensitivity. Under these conditions, our approach can determine ON and OFF power-law exponents with a precision of 3% from a comparison to numerical simulations, even for shot-noise-dominated emission signals with an average intensity below 1 photon per frame and per quantum dot. These capabilities pave the way for the unbiased, threshold-free determination of blinking power-law exponents at the micro-second timescale