Effect of Chronic Inhibition of Converting Enzyme on Renal Handling of Salt and Water: A Study on a Pediatric Population

Background/Aims: The effect of angiotensin-converting enzyme inhibition (ACEi) is amply documented in several pathological conditions. However, there are few reports about the effect of chronic ACEi on salt and water balance. The present work evaluates the effect of chronic ACEi on salt and water balance in a population of children receiving enalapril chronically in order to reduce albuminuria elicited by a uremic hemolytic syndrome. Methods: Nine children aged from 9 to 19 years with normal glomerular filtration rate, normotension and with urinary concentration capacity preserved were treated with enalapril with doses ranging between 0.1 and 0.30 mg/kg/day. Diuresis, urinary absolute and fractional excretion of Na+, K+ and urea, creatinine clearance, osmolal clearance and tubular water reabsorption were measured under three experimental procedures: (1) with free access to water; (2) with a water load and (3) with water restriction. In the last group urinary antidiuretic hormone (ADH) was measured. These tests were performed in a paired way, just before starting ACEi treatment and after 6 months of enalapril treatment. Results: Enalapril treatment diminished the urinary concentration capacity without affecting Na+ and K+ urinary excretion. Creatinine clearance was not modified except in the condition of water load where a fall in it was found after ACEi. ADH increased after enalapril treatment in children under water restriction. Conclusion: In these children chronic ACEi decreases urinary concentration capacity.Fil: Dieguez, S. M.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Dr. Teodoro Álvarez"; ArgentinaFil: Cnepa, C. A.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Dr. Teodoro Álvarez"; ArgentinaFil: Amorena, Carlos Ernesto. Universidad Nacional de General San Martn; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

High-performance visible light photodetectors based on inorganic CZT and InCZT single crystals

Herein, the optoelectrical investigation of cadmium zinc telluride (CZT) and indium (In) doped CZT (InCZT) single crystals-based photodetectors have been demonstrated. The grown crystals were configured into photodetector devices and recorded the current-voltage (I-V) and current-time (I-t) characteristics under different illumination intensities. It has been observed that the photocurrent generation mechanism in both photodetector devices is dominantly driven by a photogating effect. The CZT photodetector exhibits stable and reversible device performances to 632 nm light, including a promotable responsivity of 0.38 AW−1, a high photoswitch ratio of 152, specific detectivity of 6.30 × 1011 Jones, and fast switching time (rise time of 210 ms and decay time of 150 ms). When doped with In, the responsivity of device increases to 0.50 AW−1, photoswitch ratio decrease to 10, specific detectivity decrease to 1.80 × 1011 Jones, rise time decrease to 140 ms and decay time increase to 200 ms. Moreover, these devices show a very high external quantum efficiency of 200% for CZT and 250% for InCZT. These results demonstrate that the CZT based crystals have great potential for visible light photodetector applicationsAuthors from KKU express their appreciation to the Deanship of Scientifc Research at King Khalid University for funding this work through research groups program under grant number R.G.P. 2/42/4

Experience-based Auditory Predictions Modulate Brain Activity to Silence as do Real Sounds.

Interactions between stimuli's acoustic features and experience-based internal models of the environment enable listeners to compensate for the disruptions in auditory streams that are regularly encountered in noisy environments. However, whether auditory gaps are filled in predictively or restored a posteriori remains unclear. The current lack of positive statistical evidence that internal models can actually shape brain activity as would real sounds precludes accepting predictive accounts of filling-in phenomenon. We investigated the neurophysiological effects of internal models by testing whether single-trial electrophysiological responses to omitted sounds in a rule-based sequence of tones with varying pitch could be decoded from the responses to real sounds and by analyzing the ERPs to the omissions with data-driven electrical neuroimaging methods. The decoding of the brain responses to different expected, but omitted, tones in both passive and active listening conditions was above chance based on the responses to the real sound in active listening conditions. Topographic ERP analyses and electrical source estimations revealed that, in the absence of any stimulation, experience-based internal models elicit an electrophysiological activity different from noise and that the temporal dynamics of this activity depend on attention. We further found that the expected change in pitch direction of omitted tones modulated the activity of left posterior temporal areas 140-200 msec after the onset of omissions. Collectively, our results indicate that, even in the absence of any stimulation, internal models modulate brain activity as do real sounds, indicating that auditory filling in can be accounted for by predictive activity

Application of cathodoluminescence microscopy to the study of native acceptors in gallium antimonide

Cathodoluminescence in the scanning electron microscope is used to ivestigate growth and prosess induced defects in GaSb crystals. In particular, luminescence emission has been used to study the nature of acceptor defects present after different annealing and irradiation treatments

Modelling stand biomass fractions in Galician Eucalyptus globulus plantations by use of different LiDAR pulse densities

Aims of study: To evaluate the potential use of canopy height and intensity distributions, determined by airborne LiDAR, for the estimation of crown, stem and aboveground biomass fractions. To assess the effects of a reduction in LiDAR pulse densities on model precision. Area of study: The study area is located in Galicia, NW Spain. The forests are representative of Eucalyptus globulus stands in NW Spain, characterized by low-intensity silvicultural treatments and by the presence of tall shrub. Material and methods: Linear, multiplicative power and exponential models were used to establish empirical relationships between field measurements and LiDAR metrics. A random selection of LiDAR returns and a comparison of the prediction errors by LiDAR pulse density factor were performed to study a possible loss of fit in these models. Main results: Models showed similar goodness-of-fit statistics to those reported in the international literature. R2 ranged from 0.52 to 0.75 for stand crown biomass, from 0.64 to 0.87 for stand stem biomass, and from 0.63 to 0.86 for stand aboveground biomass. The RMSE/MEAN · 100 of the set of fitted models ranged from 17.4% to 28.4%. Models precision was essentially maintained when 87.5% of the original point cloud was reduced, i.e. a reduction from 4 pulses m–2 to 0.5 pulses m–2. Research highlights: Considering the results of this study, the low-density LiDAR data that are released by the Spanish National Geographic Institute will be an excellent source of information for reducing the cost of forest inventories

Luminescence properties of transition-metal-doped GaSb

The luminescence properties of transition-metal ͑Cr, V, and Ru͒-doped GaSb single crystals have been studied by a cathodoluminescence ͑CL͒ technique in a scanning electron microscope. Spatial segregation of impurities along the longitudinal direction of the crystals grown by the Bridgman method has been investigated. These dopants suppress the native acceptor concentration to varying extent. The behavior of Ru has been found to be different from the behavior of V and Cr. In particular the complete disappearance of the 777 meV ͑band A͒ emission has been observed in GaSb:Ru with a low doping level. A peak at 767 meV is also seen in this sample which, to the best of our knowledge, has not been previously observed in GaSb. The CL results have been complemented by x-ray-microanalysis measurements to ascertain the effect of doping level on the luminescence properties. ͓S0163-1829͑98͒05608-2

Fast and efficient microfluidic cell filter for isolation of circulating tumor cells from unprocessed whole blood of colorectal cancer patients

Liquid biopsy offers unique opportunities for low invasive diagnosis, real-time patient monitoring and treatment selection. The phenotypic and molecular profile of circulating tumor cells (CTCs) can provide key information about the biology of tumor cells, contributing to personalized therapy. CTC isolation is still challenging, mainly due to their heterogeneity and rarity. To overcome this limitation, a microfluidic chip for label-free isolation of CTCs from peripheral blood was developed. This device, the CROSS chip, captures CTCs based on their size and deformability with an efficiency of 70%. Using 2 chips, 7.5 ml of whole blood are processed in 47 minutes with high purity, as compared to similar technologies and assessed by in situ immunofluorescence. The CROSS chip performance was compared to the CellSearch system in a set of metastatic colorectal cancer patients, resulting in higher capture of DAPI+/CK+/CD45- CTCs in all individuals tested. Importantly, CTC enumeration by CROSS chip enabled stratification of patients with different prognosis. Lastly, cells isolated in the CROSS chip were lysed and further subjected to molecular characterization by droplet digital PCR, which revealed a mutation in the APC gene for most patient samples analyzed, confirming their colorectal origin and the versatility of the technology for downstream applications

Cathodoluminescence microscopy of doped GaSb crystals

We present the homogeneity and luminescence properties of bulk GaSb obtained by the cathodoluminescence (CL) technique in the scanning electron microscope. The samples used in this study are as-grown undoped and impurity diffused (tellurium) and doped (chromium) material. CL investigations have revealed a non uniform distribution of native defects in GaSb wafers. Post growth annealing in vacuum, gallium or antimony atmospheres causes an increase in homogeneity in CL images. Te diffusion and Cr doping provides new information about defects in GaSb. CL images and CL spectra recorded in these samples support that the type of defects formed is a function of diffusion time and impurity concentration