Effect of Erythropoietin on the Expression of Murine Transferrin Receptor 2

Erythropoietin (EPO) downregulates hepcidin expression to increase the availability of iron; the downregulation of hepcidin is mediated by erythroferrone (ERFE) secreted by erythroblasts. Erythroblasts also express transferrin receptor 2 (TFR2); however, the possible role of TFR2 in hepcidin downregulation is unclear. The purpose of the study was to correlate liver expression of hepcidin with the expression of ERFE and TFR2 in murine bone marrow and spleen at 4, 16, 24, 48, 72 and 96 h following administration of a single dose of EPO. Splenic Fam132b expression increased 4 h after EPO injection; liver hepcidin mRNA was decreased at 16 h. In the spleen, expression of TFR2 and transferrin receptor (TFR1) proteins increased by an order of magnitude at 48 and 72 h after EPO treatment. The EPO-induced increase in splenic TFR2 and TFR1 was associated with an increase in the number of Tfr2- and Tfr1-expressing erythroblasts. Plasma exosomes prepared from EPO-treated mice displayed increased amount of TFR1 protein; however, no exosomal TFR2 was detected. Overall, the results confirm the importance of ERFE in stress erythropoiesis, support the role of TFR2 in erythroid cell development, and highlight possible differences in the removal of TFR2 and TFR1 from erythroid cell membranes.     

Poly(3-hexylthiophene)/C60 heterojunction solar cells: Implication of morphology on performance and ambipolar charge collection

The performance of heterojunction organic solar cells is critically dependent on the morphology of the donor and acceptor components in the active film. We report results of photovoltaic devices consisting of bilayers and bulk heterojunctions using poly(3-hexylthiophene) (P3HT) and Buckminsterfullerene C₆₀. White light power efficiencies of η2.2% (bulk heterojunction) and 2.6% (bilayer) were measured after a thermal annealing step on completed devices. Optical and structural investigations on non-annealed bilayer thin films indicated a distinct porosity of the spin-coated polymer, which allows C₆₀ to penetrate the P3HT layer and to touch the anode. This resulted for these bilayer solar cells in the experimental observation that electrons were collected predominantly at the cathode after photo-excitation of P3HT, but predominantly at the anode after C₆₀ excitation. A morphological model to explain the ambipolar charge collection phenomenon is proposed.     

Superresolution algorithms for spatial extended scattering centers

Scattering centers model (SCM) is usually considered for modeling target backscattered signal in high-resolution radar. In this case the impulse response of each scattering center is represented by a time-delayed Dirac pulse. Some of most popular superresolution imagery techniques, such as MUSIC or ESPRIT, are well-matched to this model. Under this hypothesis, they outperform Fourier-based techniques in terms of both spatial and dynamic resolutions. However, the behavior of real-world targets is often very different from that of the SCM. Indeed, their reflectivity function is not confined just to several perfectly localized scattering centers, but it can be rather approximated by a set of scattering regions having different spatial extent. SCM becomes then inappropriate and the superresolution methods may provide unexpected results. Furthermore, the amplitude information is difficult to interpret in this case. In this paper we propose an extension of two superresolution methods, MUSIC and ESPRIT, to cope with extended scattering centers (ESC). According to this model, the impulse response of an ESC is not a Dirac pulse, but a window of finite support. Besides the position, the size (spatial extent) of this window is also recovered. This additional information about the target structure can be used for increasing ATR (automatic target recognition) accuracy and robustness.     

Integral transform solution for hyperbolic heat conduction in a finite slab

An analytical integral transformation of the thermal wave propagation problem in a finite slab is obtained through the generalized integral transform technique (GITT). The use of the GITT approach in the analysis of the hyperbolic heat conduction equation leads to a coupled system of second order ordinary differential equations in the time variable. The resulting transformed ODE system is then numerically solved by Gear's method for stiff initial value problems. Numerical results are presented for the local and average temperatures with different Biot numbers and dimensionless thermal relaxation times, permitting a critical evaluation of the technique performance. A comparison is also performed with previously reported results in the literature for special cases and with those produced through the application of the Laplace transform method (LTM), and the finite volume-Gear method (FVGM).     

Chronopotentiometric potential-time curves of electron transfer across the interface between two immiscible electrolyte solutions

Theoretical potential-time curves were derived that are mathematical expressions of the electron transfer reaction O1 (w) + R2(non) ? R1(w) + O2(non) proceeding at the interface of two immiscible phases between the redox couple O1/R1 in the aqueous phase (w) and the redox couple O2/R2 in the non-aqueous phase (non) under galvanostatic conditions. Procedures for the determination of the diffusion coefficients of the reactants in the corresponding phase and for the evaluation of thermodynamic and kinetic parameters of the electron transfer reaction from the potential-time curves were suggested.     

Cholera in Portugal, 1974.I. Modes of transmission

In April-November 1974, Portugal had a cholera epidemic caused by Vibrio cholerae El Tor Inaba with 2467 bacteriologically confirmed hospitalized cases and 48 deaths. Most of the country was affected, with 17 of the 18 districts reporting cases. V. cholerae was isolated from 42 per cent of shellfish tested during the epidemic, and an epidemiologic study found that a history of consumption of raw or poorly cooked cockles was significantly more common among cholera patients than among paired controls. Water from a spring and a brand of commercially bottled water were also found to be vehicles of transmission of cholera. Although night soil was sometimes used on gardens, consumption of raw fruits and vegetables was not associated with illness.     

Estimation of serum gentamicin by quenching fluoroimmunoassay

A new type of non-isotopic immunoassay, applied to the determination of serum gentamicin, is reported. The method is based on partial quenching of fluorescence observed when fluorescein-labelled gentamicin is bound by anti-gentamicin serum. The fluorescence intensity of the labelled gentamicin in an unseparated immunoassay incubation mixture therefore serves to indicate the extent of binding, which is related to the amount of competing unlabelled gentamicin present. Precision and accuracy are shown to be similar to those of the best existing methods for gentamicin, while the new assay is more rapid and technically simpler, and avoids the use of expensive radio-chemicals with their attendant health hazard. Assays of patient samples correlate with established bioassay and polarisation fluoroimmunoassay methods.