Synthesis and in vitro leishmanicidal activity of novel N-arylspermidine derivatives.

This work describes the synthesis and biological evaluation of hitherto unknown N-arylspermidine derivatives 3. Compounds 3 were efficiently prepared from cyclic amidines through a novel synthetic approach comprising alkylation with ω-halonitriles followed by reduction. The cyclic N-arylamidine directs the alkylation to the unsubstituted nitrogen and also provides the N-benzyl group present in the triamine after simultaneous reduction of the resulting quaternary salt 2 and the cyano group.

Structure and dynamics of the interaction of Delta and Omicron BA.1 SARS-CoV-2 variants with REGN10987 Fab reveal mechanism of antibody action.

Study of mechanisms by which antibodies recognize different viral strains is necessary for the development of new drugs and vaccines to treat COVID-19 and other infections. Here, we report 2.5 Å cryo-EM structure of the SARS-CoV-2 Delta trimeric S-protein in complex with Fab of the recombinant analog of REGN10987 neutralizing antibody.

Acetyl-L-Carnitine Aids in Preservation of Cholinergic Neurons and Memory in the Drosophila melanogaster Model of Alzheimer's Disease.

Background: The lack of effective therapy for the treatment of Alzheimer's disease demands both the search for new drugs and the reconsideration of already known substances currently used in other areas of medicine. Drosophila melanogaster offers the potential to model features of Alzheimer's disease, study disease mechanisms, and conduct drug screening.

Objectives: The purpose of this work was to analyze the neuroprotective properties of the drug "carnicetine", which is an acetylated form of the natural low molecular weight compound L-carnitine.

EuPtPb and SrPtPb-lead-based intermetallics with YRhSn/NdRhSn-type polyanionic platinum-lead 3D frameworks.

Two platinide plumbides, EuPtPb and SrPtPb, were discovered using high-temperature exploratory synthesis and flux-assisted crystal growth. Their crystal structures were determined from single-crystal X-ray diffraction. Both compounds crystallize in the orthorhombic system; EuPtPb belongs to the YRhSn structure type (2, = 4.

Nose-to-Brain Delivery of Biomimetic Nanoparticles for Glioblastoma Targeted Therapy.

Glioblastoma (GBM) is an extremely aggressive form of brain cancer that remains challenging to treat, especially owing to the lack of effective targeting and drug delivery concerns. Due to its anatomical advantages, the nose-to-brain strategy is an interesting route for drug delivery. Nanoengineering has provided technological tools and innovative strategies to overcome biotechnological limitations, which is promising for improving the effectiveness of conventional therapies.

Effects of clustering heterogeneity on the spectral density of sparse networks.

We derive exact equations for the spectral density of sparse networks with an arbitrary distribution of the number of single edges and triangles per node. These equations enable a systematic investigation of the effects of clustering on the spectral properties of the network adjacency matrix. In the case of heterogeneous networks, we demonstrate that the spectral density becomes more symmetric as the fluctuations in the triangle-degree sequence increase.

Residual Stress Distribution in Dievar Tool Steel Bars Produced by Conventional Additive Manufacturing and Rotary Swaging Processes.

The impact of manufacturing strategies on the development of residual stresses in Dievar steel is presented. Two fabrication methods were investigated: conventional ingot casting and selective laser melting as an additive manufacturing process. Subsequently, plastic deformation in the form of hot rotary swaging at 900 °C was applied.

Diverse Cyclization Pathways Between Nitriles with Active -Methylene Group and Ambiphilic 2-Pyridylselenyl Reagents Enabled by Reversible Covalent Bonding.

Herein, we describe a novel coupling between ambiphilic 2-pyridylselenyl reagents and nitriles featuring an active α-methylene group. Depending on the solvent employed, this reaction can yield two distinct types of cationic pyridinium-fused selenium-containing heterocycles, 1,3-selenazolium or 1,2,4-selenadiazolium salts, in high yields. This is in contrast to what we observed before for other nitriles.

Enhanced Thermal Conductivity of Thermoplastic Polyimide Nanocomposites: Effect of Using Hexagonal Nanoparticles.

Thermoplastic polyimides have garnered significant interest in the electronic and electrical industries owing to their performance characteristics. However, their relatively low thermal conductivity coefficients pose a challenge. To address this issue, this study focused on the properties of nanocomposites comprising two thermoplastic semicrystalline polyimides R-BAPB and BPDA-P3, one amorphous polyimide ULTEM, and hexagonal nanoparticles.

Current Role and Potential of Triple Quadrupole Mass Spectrometry in Biomedical Research and Clinical Applications.

Mass-spectrometry-based assays nowadays play an essential role in biomedical research and clinical applications. There are different types of commercial mass spectrometers on the market today, and triple quadrupole (QqQ) is one of the time-honored systems. Here, we overview the main areas of QqQ applications in biomedicine and assess the current level, evolution, and trends in the use of QqQ in these areas.

Characterization of the Microstructure of SrBaNbO Thin Films by Brillouin Light Scattering.

Strontium-barium niobate (SrBaNbO) films can be considered as a promising material for microwave applications due to high dielectric nonlinearity and relatively low losses. Since strontium-barium niobate has a disordered structure that determines its unique electrical properties, the identification of structural features of the SrBaNbO films is the key to their successful use. The SrBaNbO films were synthesized on a sapphire substrate by magnetron sputtering.

Potential of photodynamic therapy using polycationic photosensitizers in the treatment of lung cancer patients with SARS-CoV-2 infection and bacterial complications: Our recent experience.

The problem of treating cancer patients with lung cancer has become more difficult due to the SARS-CoV-2 viral infection and concomitant bacterial lesions. The analysis shows that the photodynamic effect of long-wavelength polycationic photosensitizers suppresses the tumor process (including the destruction of cancer stem cells), SARS-CoV-2 coronavirus infection, Gram-positive and Gram-negative bacteria, including those that can cause pneumonia. Therefore, the photodynamic approach using such photosensitizers is promising for the development of an effective treatment method for patients with lung cancer, including those with SARS-CoV-2 infection and bacterial complications.

Lithium niobate thin film electro-optic modulator.

The linear electro-optic effect offers a valuable means to control light properties via an external electric field. Lithium niobate (LN), with its high electro-optic coefficients and broad optical transparency ranges, stands out as a prominent material for efficient electro-optic modulators. The recent advent of lithium niobate-on-insulator (LNOI) wafers has sparked renewed interest in LN for compact photonic devices.

Momentum space separation of quantum path interferences between photons and surface plasmon polaritons in nonlinear photoemission microscopy.

Quantum path interferences occur whenever multiple equivalent and coherent transitions result in a common final state. Such interferences strongly modify the probability of a particle to be found in that final state, a key concept of quantum coherent control. When multiple nonlinear and energy-degenerate transitions occur in a system, the multitude of possible quantum path interferences is hard to disentangle experimentally.

High-Statistics Measurement of the Cosmic-Ray Electron Spectrum with H.E.S.S.

Owing to their rapid cooling rate and hence loss-limited propagation distance, cosmic-ray electrons and positrons (CRe) at very high energies probe local cosmic-ray accelerators and provide constraints on exotic production mechanisms such as annihilation of dark matter particles. We present a high-statistics measurement of the spectrum of CRe candidate events from 0.3 to 40 TeV with the High Energy Stereoscopic System, covering 2 orders of magnitude in energy and reaching a proton rejection power of better than 10^{4}.

Electrospinning of methacrylated alginate for tissue engineering applications.

Photo-crosslinkable methacrylated alginate derivatives (M-ALGs) were synthesized modification of sodium alginate with glycidyl methacrylate. Needle (capillary) and needleless electrospinning techniques were employed to produce their nonwoven fiber mats. Spinning parameters such as applied voltage, solution composition, and flow rate were optimized to form uniform bead-free fibers with an average diameter of about 150 nm.

Search for violation in decays in proton-proton collisions at .

A search is reported for charge-parity violation in decays, using data collected in proton-proton collisions at recorded by the CMS experiment in 2018. The analysis uses a dedicated data set that corresponds to an integrated luminosity of 41.6 , which consists of about 10 billion events containing a pair of b hadrons, nearly all of which decay to charm hadrons.

Measurement of the electric potential and the magnetic field in the shifted analysing plane of the KATRIN experiment.

The projected sensitivity of the effective electron neutrino-mass measurement with the KATRIN experiment is below 0.3 eV (90 % CL) after 5 years of data acquisition. The sensitivity is affected by the increased rate of the background electrons from KATRIN's main spectrometer.

Differential effect of cerium nanoparticles on the viability, redox-status and Ca-signaling system of cancer cells of various origins.

The present study aims to understand the molecular mechanism underlying the therapeutic effect of cerium nanoparticles (CeNPs) in oncology. Cancer cells were treated with different concentrations of pure nanocerium of different sizes synthesized by laser ablation. Due to the not insignificant influence of surface defects and oxygen species on the ROS-modulating properties of cerium nanoparticles, the nanoparticles were not coated with surfactants or organic molecules during synthesis, which could potentially inhibit a number of pro-oxidative effects.

Mucoadhesive polyelectrolyte complexes of fucoidan and chitin nanowhiskers to prolong the antiprotozoal activity of metronidazole.

The improvement of the specific pharmacological activity of agents with antimicrobial and antiprotozoal properties (e.g. metronidazole, MET) is of interest for clinical applications in the treatment of bacterial infections.

Chiral Dichroism in Resonant Metasurfaces with Monoclinic Lattices.

We demonstrate that chiral response can be achieved in resonant metasurfaces with a monoclinic lattice symmetry (the so-called Bravais oblique lattices) where the mirror symmetry is broken by the lattice asymmetry and also by a substrate, whereas each individual meta-atom remains fully achiral. We describe the underlying physics by introducing a mode chirality parameter as a quantitative measure of the lattice chiral eigenmodes. We confirm experimentally selective linear and nonlinear chiral interaction of resonant silicon metasurfaces with circularly polarized light.

Finite Bubble Statistics Constrain Late Cosmological Phase Transitions.

We consider first order cosmological phase transitions (PTs) happening at late times below standard model temperatures T_{PT}≲GeV. The inherently stochastic nature of bubble nucleation and the finite number of bubbles associated with a late-time PT lead to superhorizon fluctuations in the PT completion time. We compute how such fluctuations eventually source curvature fluctuations with universal properties, independent of the microphysics of the PT dynamics.

Advancements in organic fluorescent materials: unveiling the potential of peripheral group modification in dithienyl-diketopyrrolopyrrole derivatives for one- and two-photon bioimaging.

The quest for novel organic fluorescent materials capable of two-photon absorption (2PA) has intensified in recent years due to their promising applications in biological imaging. Two-photon fluorescence microscopy (2PFM) offers high spatial-temporal resolution, reduced photodamage, and deeper tissue penetration compared to conventional techniques. However, the development of bright two-photon molecular markers remains a challenge, necessitating compounds with high fluorescence quantum yield and 2PA cross-section ().