Granulatosides D,E and other polar steroid compounds from the starfish Choriaster granulatus. Their immunomodulatory activity and cytotoxicity

Two new steroid glycosides, granulatosides D (1) and E (2), belonging to the group of bi- and monoglycosides of polyhydroxysteroids, respectively, were isolated from the ethanolic extract of the starfish Choriaster granulatus along with thirteen previously known glycosides of polyhydroxysteroids (3–15) and one steroid heptaol (16). The structures of the new compounds were elucidated by extensive NMR and ESIMS techniques. Cytotoxic and immunomodulatory activities of compounds 1, 3–8, and 10–16 using murine splenocytes and peritoneal macrophages were studied. At a dose of 0.1 μM new glycoside 1 showed immunomodulatory properties, increasing the intracellular ROS (reactive oxygen species) level in peritoneal murine macrophages by 20% and decreasing intracellular ROS level by 21% in pre-treated with endotoxic lipopolysaccharide from E. coli (LPS) peritoneal macrophages.     

Application of solid‐phase microextraction in current biomedical research

Extraction of endogenous compounds and drugs and their corresponding metabolites from complex matrices, such as biofluids and solid tissues, requires adequate analytical approach facilitating qualitative and quantitative analysis. To this end, solid‐phase microextraction has been introduced as modern technology that is capable of efficient and high‐throughput extraction of compounds due to its ability to amalgamate sampling, extraction, and pre‐concentration steps, while requiring minimal use of organic solvents. The ability of solid‐phase microextraction to enable analyses on small‐volume biological samples and growing availability of biocompatible solid‐phase microextraction coatings make it a highly useful technology for variety of applications. For example, solid‐phase microextraction is particularly useful for identifying biomarkers in metabolomics studies, and it can be successfully applied in pharmaceutical and toxicological studies requiring the fast and sensitive determination of drug levels, especially those that are present at low levels in biological matrices such as plasma, urine, saliva, and hair. Moreover, solid‐phase microextraction can be directly applied in in vivo studies because this extraction technique is non‐exhaustive and its biocompatible probes offer minimal invasiveness to the analyzed system. In this article, we review recent progress in well‐established solid‐phase microextraction technique for in vitro and in vivo analyses of various metabolites and drugs in clinical, pharmaceutical, and toxicological applications.     

3D Multilayered paper‐ and thread/paper‐based microfluidic devices for bioassays

In this paper we describe the fabrication of novel 3D microfluidic paper‐based analytical devices (3D‐μPADs) and a 3D microfluidic thread/paper‐based analytical device (3D‐μTPAD) to detect glucose and BSA through colorimetric assays. The 3D‐μPAD and 3D‐μTPAD consisted of three (wax, heat pressed wax‐printed paper, single‐sided tape) and four (hole‐punched single‐sided tape, blank chromatography circles, heat‐pressed wax‐printed paper, hole‐punched single‐sided tape containing trifurcated thread) layers, respectively. The saturation curves for each assay were generated for all platforms. For the glucose assay, a solution of glucose oxidase (GOx), horseradish peroxidase, and potassium iodide was flowed through each platform and, upon contact with glucose, generated a yellow‐brown color indicative of the oxidation of iodide to iodine. For the protein assay, BSA was flowed through each device and, upon contact with citrate buffer and tetrabromophenol blue, resulted in a color change from yellow to blue. The devices were dried, scanned, and analyzed yielding a correlation between either yellow intensity and glucose concentration or cyan intensity and BSA concentration. A similar glucose assay, using unknown concentrations of glucose in artificial urine, was conducted and, when compared to the saturation curve, showed good correlation between the theoretical and actual concentrations (percent differences <10%). The development of 3D‐μPADs and 3D‐μTPADs can further facilitate the use of these platforms for colorimetric bioassays.     

An Experimental Study of the External-Signal Influence on the Oscillation Regime of a Megawatt Gyrotron

Radiophysics and Quantum Electronics - The radiation-frequency locking by an external signal is experimentally studied for a megawatt gyrotron. An external signal from a magnetron is applied to the...     

Self-Broadening and Carbon-Dioxide Broadening of Lines of the H<Subscript>2</Subscript>S Molecule

Carbon-dioxide-broadening coefficients and self-broadening coefficients of lines of the main isotopic modification of Н₂S are estimated on the basis of literature data. The J′-dependences of the above line-profile parameters of the hydrogen-sulfide molecule are examined. In the case of CO₂ broadening, the half-widths of lines are calculated by a semiempirical method based on a parametric modification of the impact semiclassical model; the model parameters were determined from the fit to experimental data.     

Quantum Locality,Rings a Bell?: Bell’s Inequality Meets Local Reality and True Determinism

By assuming a deterministic evolution of quantum systems and taking realism into account, we carefully build a hidden variable theory for Quantum Mechanics (QM) based on the notion of ontological states proposed by ’t Hooft (The cellular automaton interpretation of quantum mechanics, arXiv:1405.1548v3, 2015; Springer Open 185,  https://doi.org/10.1007/978-3-319-41285-6, 2016). We view these ontological states as the ones embedded with realism and compare them to the (usual) quantum states that represent superpositions, viewing the latter as mere information of the system they describe. Such a deterministic model puts forward conditions for the applicability of Bell’s inequality: the usual inequality cannot be applied to the usual experiments. We build a Bell-like inequality that can be applied to the EPR scenario and show that this inequality is always satisfied by QM. In this way we show that QM can indeed have a local interpretation, and thus meet with the causal structure imposed by the Theory of Special Relativity in a satisfying way.     

Nano-Templates from Thermoresponsive Poly(ethoxytriethyleneglycol acrylate) for Polymeric Nano-Capsules

Temperature responsive poly(ethoxytriethyleneglycol acrylate) (PETEGA) of Mn = 8000 and M_w/M_n = 2.30 was synthesized by ATRP. Dilute aqueous solutions of PETEGA exhibit lower critical solution temperature (LCST) at around 34 °C. We found that PETEGA can form nano-sized uniform colloidal aggregates (50-200 nm) above LCST either with or without an additional surfactant. Therefore PETEGA nano-aggregates were used as templates for the seeded free radical copolymerization of acrylamides or methacrylates together with a cross-linker to form acrylamide or methacrylate based core-shell particles. The formation of the PETEGA templates was investigated by dynamic light scattering (DLS) in order to find optimal conditions for obtaining narrow dispersed aggregates of desired sub-micron dimensions. Core-shell particles were characterized by DLS and scanning electron microscopy.     

Synthesis and Evaluation of Biological Activities of Bis(spiropyrazolone)cyclopropanes: A Potential Application against Leishmaniasis

This work focuses on the search and development of drugs that may become new alternatives to the commercial drugs currently available for treatment of leishmaniasis. We have designed and synthesized 12 derivatives of bis(spiropyrazolone)cyclopropanes. We then characterized their potential application in therapeutic use. For this, the in vitro biological activities against three eukaryotic models—S. cerevisiae, five cancer cell lines, and the parasite L. mexicana—were evaluated. In addition, cytotoxicity against non-cancerous mammalian cells has been evaluated and other properties of interest have been characterized, such as genotoxicity, antioxidant properties and, in silico predictive adsorption, distribution, metabolism, and excretion (ADME). The results that we present here represent a first screening, indicating two derivatives of bis(spiropyrazolone)cyclopropanes as good candidates for the treatment of leishmaniasis. They have good specificity against parasites with respect to mammalian cells.     

Multicanonical sampling of the space of states of ℋ(2, <Emphasis Type="Italic">n</Emphasis>)-vector models

Problems of temperature behavior of specific heat are solved by the entropy simulation method for Ising models on a simple square lattice and a square spin ice (SSI) lattice with nearest neighbor interaction, models of hexagonal lattices with short-range (SR) dipole interaction, as well as with long-range (LR) dipole interaction and free boundary conditions, and models of spin quasilattices with finite interaction radius. It is established that systems of a finite number of Ising spins with LR dipole interaction can have unusual thermodynamic properties characterized by several specific-heat peaks in the absence of an external magnetic field. For a parallel multicanonical sampling method, optimal schemes are found empirically for partitioning the space of states into energy bands for Ising and SSI models, methods of concatenation and renormalization of histograms are discussed, and a flatness criterion of histograms is proposed. It is established that there is no phase transition in a model with nearest neighbor interaction on a hexagonal lattice, while the temperature behavior of specific heat exhibits singularity in the same model, in case of LR interaction. A spin quasilattice is found that exhibits a nonzero value of residual entropy.