Harnessing Mechanical Deformation to Reduce Spherical Aberration in Soft Lenses.

Mechanical deformation has recently emerged as a promising platform to realize optical devices with tunable response. While most studies to date have focused on the tuning of the focal length, here we use a combination of experiments and analyses to show that an applied tensile strain can also largely reduce spherical aberration. We first demonstrate the concept for a cylindrical elastomeric lens and then show that it is robust and valid over a range of geometries and material properties. As such, our study suggests that large mechanical deformations may provide a simple route to achieve the complex profiles required to minimize aberration and realize lenses capable of producing images of superior quality.

Principal Metabolites in Extracts of Different Plants Responsible for Antibacterial Effects.

The increase in bacterial resistance and decreased effectiveness of antibacterial agents has forced researchers to look for new antibacterial agents from environmentally friendly sources such as essential oils and oil extracts. The functional group of the metabolites present in the essential oils or plant extract and the synergy effects between them play an important role in the biological activity and can be the principal factor affecting the antibacterial effect. All of these bioactive oils showed the same action mechanism, and the best way to implement them is by extracting them without changing their original properties, whereby the characterization and evaluation of the compounds are important steps. All of these themes are extensively reviewed, analyzed, and discussed in this work.

3D spatiotemporally scalable in vivo neural probes based on fluorinated elastomers.

Electronic devices for recording neural activity in the nervous system need to be scalable across large spatial and temporal scales while also providing millisecond and single-cell spatiotemporal resolution. However, existing high-resolution neural recording devices cannot achieve simultaneous scalability on both spatial and temporal levels due to a trade-off between sensor density and mechanical flexibility. Here we introduce a three-dimensional (3D) stacking implantable electronic platform, based on perfluorinated dielectric elastomers and tissue-level soft multilayer electrodes, that enables spatiotemporally scalable single-cell neural electrophysiology in the nervous system. Our elastomers exhibit stable dielectric performance for over a year in physiological solutions and are 10,000 times softer than conventional plastic dielectrics. By leveraging these unique characteristics we develop the packaging of lithographed nanometre-thick electrode arrays in a 3D configuration with a cross-sectional density of 7.6 electrodes per 100 µm2. The resulting 3D integrated multilayer soft electrode array retains tissue-level flexibility, reducing chronic immune responses in mouse neural tissues, and demonstrates the ability to reliably track electrical activity in the mouse brain or spinal cord over months without disrupting animal behaviour.

Characteristics of Induced-Sputum Inflammatory Phenotypes in Adults with Asthma: Predictors of Bronchial Eosinophilia.

Purpose: The objectives of this study were, for patients attending a specialist asthma clinic at a tertiary care hospital, to determine, from sputum induction (SI), proportions of bronchial inflammatory phenotypes, demographic, clinical and functional characteristics of each phenotype, and the most accessible non-invasive inflammatory marker that best discriminates between phenotypes. Patients and Methods: Included were 96 patients with asthma, attending a specialist asthma clinic at a tertiary care hospital, who underwent testing as follows: SI, spirometry, fractional exhaled nitric oxide (FeNO), blood eosinophilia, total immunoglobulin E (IgE), and a skin prick test. Results: SI phenotypes were 46.9% eosinophilic, 33.3% paucigranulocytic, 15.6% neutrophilic, and 4.2% mixed. No significantly different clinical or functional characteristics were observed between the phenotypes. A positive correlation was observed between SI eosinophilia and both emergency visits in the last 12 months (p = 0.041; r = 0.214) and FeNO values (p = 0.000; r = 0.368). Blood eosinophilia correlated with SI eosinophilia (p = 0.001; r = 0.362) and was the best predictor of bronchial eosinophilia, followed by FeNO, and total blood IgE (area under the receiver operating characteristic curve (AUC-ROC) 72%, 65%, and 53%, respectively), although precision was only fair. Conclusion: In consultations for severe asthma, the most frequent phenotype was eosinophilic. Peripheral blood eosinophilia is a reliable marker for discriminating between different bronchial inflammatory phenotypes, is useful in enabling doctors to select a suitable biologic treatment and so prevent asthma exacerbation, and is a better predictor of bronchial eosinophilia than FeNO and IgE values.

Study of electrospun nanofibers loaded with Ru(ii) phenanthroline complexes as a potential material for use in dye-sensitized solar cells (DSSCs).

Dye-sensitized solar cells (DSSCs) are an increasingly attractive alternative energy source because of their low cost. Therefore, researchers have intensified efforts over the past decade to increase their energy conversion efficiency by employing new materials in each DSSC component. The present research focuses on synthesizing electrospun nanofibers as a potential new material as a counter electrode in DSSCs. Two Ru(ii) half sandwich 1,10 phenanthroline (phen) Ru-1 and 5-amino- phen Ru-2 complexes were prepared for its functionalization. As a deposition medium, poly(caprolactone) (PCL) dissolved in chloroform was used. Different Ru(ii) complex concentrations were made at 0.1% wt., 0.5% wt., and 1% wt. Thermal characterization studies using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were conducted to evaluate the behavior and weight loss of the samples with temperature variations. Fourier transform infrared spectroscopy (FTIR) measurements were taken to observe the bond interaction of the ruthenium complexes and the PCL. Finally, scanning electron microscopy (SEM) was used to structurally and morphologically evaluate the fiber distribution and porosity. These fibers have a homogeneous morphology, without bulbs, but with evident solid inlays on the surface, with fibers between ∼0.58 to 2.47 µm and percentages of porosity ∼45%. TGA and DSC thermograms show minor temperature variations that demonstrate the incorporation of the Ru(ii) complexes into the fiber. Furthermore, the melting and degradation temperature of the fibers is suitable for use in a DSSC approach. The incorporation of the ruthenium compounds into PCL fibers, along with the addition of the NH2 group into complex Ru-2, resulted in a higher current density for both anodic and cathodic peaks in Cyclic Voltammetry (CV). It is noteworthy that from I-V curves, PCL-Ru2 1% fibers demonstrated a conductivity of 0.461 µS cm-1, which is comparable to other PCL fibers carrying a higher metal load. Future studies will delve into the mechanical properties of these fibers to highlight their potential for application in this field.

Identification of Two Eosinophil Subsets in Induced Sputum from Patients with Allergic Asthma According to CD15 and CD66b Expression.

Two subsets of eosinophils have been described: resident eosinophils with homeostatic functions (rEOS) in healthy subjects and in patients with nonallergic eosinophilic asthma, and inflammatory eosinophils (iEOS) in blood and lung samples from patients with allergic asthma. We explored if it would be possible to identify different subsets of eosinophils using flow cytometry and the gating strategy applied to induced sputum. We conducted an observational cross-sectional single-center study of 62 patients with persistent allergic asthma. Inflammatory cells from induced sputum samples were counted by light microscopy and flow cytometry, and cytokine levels in the supernatant were determined. Two subsets of eosinophils were defined that we call E1 (CD66b-high and CD15-high) and E2 (CD66b-low and CD15-low). Of the 62 patients, 24 were eosinophilic, 18 mixed, 10 paucigranulocytic, and 10 neutrophilic. E1 predominated over E2 in the eosinophilic and mixed patients (20.86% vs. 6.27% and 14.42% vs. 4.31%, respectively), while E1 and E2 were similar for neutrophilic and paucigranulocytic patients. E1 correlated with IL-5, fractional exhaled nitric oxide, and blood eosinophils. While eosinophil subsets have been identified for asthma in blood, we have shown that they can also be identified in induced sputum.

Drug release from complexes with a series of poly(carboxyalkyl methacrylates), a new class of weak polyelectrolytes.

Carboxyalkyl methacrylates, a new class of non-cross-linked, hydrophobic weak polyelectrolytes, were synthesized, and then bound to cationic drugs (propranolol.HCl, diltiazem.HCl and verapamil.HCl) to form water-insoluble complexes that release the bound drug only in ionic media (pH 7.4). Compressed tablets were prepared from these cation exchange polyelectrolytes. Release profiles followed zero order kinetics (n>0.90; n is the release exponent). As the hydrophobicity of the polyelectrolytes increased, the rate of release decreased and deviated from linearity (n=0.7). Both the ionic strength of the medium as well as the solubility of the drug affected the rate of release. In acidic media (pH 1.2) a burst of drug was released but the release was halted by a layer of non-ionized polymer precipitated on the surface of the tablets. The results indicate that it is possible to "tailor-make" the release kinetics by using a polyelectrolyte from the series with the suitable hydrophobicity.

Study of the morphology of ZnS thin films deposited on different substrates via chemical bath deposition.

In this work, the influence of substrate on the morphology of ZnS thin films by chemical bath deposition is studied. The materials used were zinc acetate, tri-sodium citrate, thiourea, and ammonium hydroxide/ammonium chloride solution. The growth of ZnS thin films on different substrates showed a large variation on the surface, presenting a poor growth on SiO2 and HfO2 substrates. The thin films on ITO substrate presented a uniform and compact growth without pinholes. The optical properties showed a transmittance of about 85% in the visible range of 300-800 nm with band gap of 3.7 eV.