Aeromyocological survey in the Santiago Western district (author''s transl)

It has not been determined whether Rho (D)-negative infants born of Rho (D)-positive mothers are sensitized during gestation or during parturition. Sensitization before use precludes the efficacious use of human Rho immune globulin as a prophylactic. The purpose of the present study is to identify the time of sensitization. Cord blood was collected from the placentas of 68 Rho (D)-negative infants whose mothers were Rho (D)-positive. Sixty-three of the 68 infants had one blood sample obtained between 1 and 9 months later. The paired samples were analyzed for anti-D by standard Coombs test and by automated antibody detection techniques. With the technique of automated antibody detection, we have been unable to demonstrate antibody in cord blood of the Rho (D)-negative infants of whom at least 7 of 63 (11%) had detectable anti-D between 1 and 9 months of age. These data show that Rho (D)-negaitve infants do not have detectable antibody at birth but may develop detectable anti-D in the first months of life. This observation suggests that the sensitizing dose of Rho (D) antigen occurs at parturition rather than during gestation.     

Eliminating the ambiguity in nonperturbation microwave measurementsof permittivity

The authors propose a method for eliminating the ambiguity in the dielectric constant which appears in many measurement techniques at microwave frequencies. They describe the procedure in a general way and apply it to the TE cavity technique to measure the permittivity of liquids and to the short-circuited line technique. The viability of the procedure and its simplicity compared with commonly used methods are shown. Complicated calculations involved in the comparison of two sets of solutions of two transcendental equations are avoided, and the correct value of the dielectric constant is obtained from the root of a simple algebraic equation     

Spectrophotometric assay for copper and iron in transformer oil using partial least squares regression (PLS2)

A simple and low cost spectrophotometric assay is proposed in this work for simultaneous determination of copper and iron levels in insulating oils. The procedure requires minimum sample volume (250 muL), it is carried out in disposable micro tubes (1.5 mL) and aqueous standards are used for calibration. In brief, after dilution with n-propanol, the wear metals are extracted with hydrochloric acid and, after neutralization, the analytes are reduced to the oxidation states Cu(I) and Fe(II) respectively. Finally, the mixture of bathocuproine-disulfonic acid and bathophenantroline-disulfonic acid is added for selective formation of copper and iron complexes. Then, chloroform and methanol are added, the sample is centrifuged and absorption spectra are registered in the upper-aqueous layer (470-550 nm). Multivariate calibration, covering concentration range 0-4 mug/mL of each analyte in oil is performed using partial least squares regression. The test solutions are prepared by spiking the aqueous standards of copper and iron to metal-free oil diluted with n-propanol (1:1). The prediction results were in agreement with those obtained using univariate spectrophotometric assay (one ligand) and those obtained by electrothermal atomic absorption spectrometry (after dissolution of wear metals and dilution with n-propanol)     

Short communication: Patterns of fecal shedding of Klebsiella by dairy cows

Patterns and persistency of fecal shedding of Klebsiella spp. by healthy adult dairy cattle were explored with probabilistic, statistical, and molecular methods. Fecal shedding was monitored longitudinally in 92 animals in 1 herd for 5 mo. Shedding patterns followed a random binomial distribution, and associations with host factors were not detected. For 12 animals from 4 herds, strain-typing of multiple fecal Klebsiella isolates was performed by means of random-amplified polymorphic DNA typing. For 2 animals, additional typing was performed on isolates from samples collected on several consecutive days. A large variety of Klebsiella strains was detected within samples (on average, 3.1 strains per 4 isolates) and between samples (18 of 20 strains were detected only once in feces from cows that were sampled for 5 d consecutively). Results from each method suggest that fecal shedding of Klebsiella is associated with transient rather than persistent presence of the organism in the gastrointestinal tract.     

Artificial neural network approach to predict the lubricated friction coefficient

This paper analyses the applicability of artificial neural networks for predicting the lubricated friction coefficient. We will consider their use as faster and simpler alternatives to simulations based on theoretical behaviour equations. The development of several different artificial neural networks is presented. They have been trained through tribological tests on a mini‐traction‐machine, which furnishes the friction coefficient in point contacts. Once the training has been completed the networks are applied as tools for predicting the results in different operating conditions. Their advantages and disadvantages are analysed compared with conventional simulation tools. Copyright © 2013 John Wiley & Sons, Ltd.     

Development of Biodegradable GQDs-hMSNs for Fluorescence Imaging and Dual Cancer Treatment via Photodynamic Therapy and Drug Delivery

Recently, nano-based cancer therapeutics have been researched and developed, with some nanomaterials showing anticancer properties. When it comes to cancer treatment, graphene quantum dots (GQDs) contain the ability to generate ¹O₂, a reactive oxidative species (ROS), allowing for the synergistic imaging and photodynamic therapy (PDT) of cancer. However, due to their small particle size, GQDs struggle to remain in the target area for long periods of time in addition to being poor drug carriers. To address this limitation of GQDs, hollow mesoporous silica nanoparticles (hMSNs) have been extensively researched for drug delivery applications. This project investigates the utilization and combination of biomass-derived GQDs and Stöber silica hMSNs to make graphene quantum dots-hollow mesoporous silica nanoparticles (GQDs-hMSNs) for fluorescent imaging and dual treatment of cancer via drug delivery and photodynamic therapy (PDT). Although the addition of hMSNs made the newly synthesized nanoparticles slightly more toxic at higher concentrations, the GQDs-hMSNs displayed excellent drug delivery using fluorescein (FITC) as a mock drug, and PDT treatment by using the GQDs as a photosensitizer (PS). Additionally, the GQDs retained their fluorescence through the surface binding to hMSNs, allowing them to still be used for cell-labeling applications.     

Low Energy Blue Pulsed Light-Activated Injectable Materials for Restoring Thinning Corneas

Many alternatives to human donor corneas are being developed to meet the global shortage of donated tissues. However, corneal transplantation remains the gold standard for diseases resulting in thinning corneas. In this study, transparent low energy photoactivated extracellular matrix-mimicking materials are developed for intrastromal injection to restore stromal thickness. The injectable biomaterials are comprised of short peptides and glycosaminoglycans (chondroitin, hyaluronic acid) that assemble into a hydrogel when pulsed with low-energy blue light. The dosage of pulsed-blue light needed for material activation is minimal at 8.5 mW cm⁻², thus circumventing any blue light cytotoxicity. Intrastromal injection of these light-activated biomaterials in rat corneas shows that two iterations of the formulations remain stable in situ without stimulating significant inflammation or neovascularization. The use of low light intensities and the ability of the developed materials to stably rebuild and change the curvature of the cornea tissue make these formulations attractive for clinical translation.