Naturally derived nano- and micro-drug delivery vehicles: halloysite, vaterite and nanocellulose

Recent advances in drug delivery and controlled release had a great impact on bioscience, medicine and tissue engineering. Consequently, a variety of advanced drug delivery vehicles either have already reached the market or are approaching the phase of commercial production. Progressive growth of the drug delivery market has led to the necessity to earnestly concern about economically viable, up-scalable and sustainable technologies for a large-scale production of drug delivery carriers. We have identified three attractive natural sources of drug carriers: aluminosilicate clays, minerals of calcium carbonate, and cellulose. Three classes of drug delivery carriers derived from these natural materials are halloysite nanotubes, vaterite crystals and nanocellulose. These carriers can be produced using “green” technologies from some of the most abundant sources on the Earth and have extremely high potential to meet all criteria applied for the manufacture of modern delivery carriers. We provide an up-to-date snapshot of these drug delivery vehicles towards their use for bioapplications, in particular for drug delivery and tissue engineering. The following research topics are addressed: (i) the availability, sources and methodologies used for production of these drug delivery vehicles, (ii) the drug loading and release mechanisms of these delivery vehicles, (iii) in vitro, in vivo, and clinical studies on these vehicles, and (iv) employment of these vehicles for tissue engineering. Finally, the prospects for vehicles’ further development and industrialisation are critically assessed, highlighting most attractive future research directions such as the design of third generation active biomaterials

Discovery of an unusual bright eclipsing binary with the longest known period: TYC 2505-672-1 / MASTER OT J095310.04+335352.8

We report on the MASTER Global Robotic Net discovery of an eclipsing binary, MASTER OT J095310.04+335352.8, previously known as unremarkable star TYC 2505-672-1, which displays extreme orbital parameters. The orbital period P=69.1 yr is more than 2.5 times longer than that of epsilon-Aurigae, which is the previous record holder. The light curve is characterized by an extremely deep total eclipse with a depth of more than 4.5 mag, which is symmetrically shaped and has a total duration of 3.5 yrs. The eclipse is essentially gray. The spectra acquired with the Russian 6 m BTA telescope both at minimum and maximum light mainly correspond to an M0-1III--type red giant, but the spectra taken at the bottom of eclipse show small traces of a sufficiently hot source. The observed properties of this system can be better explained as the red giant eclipsed by a large cloud (the disk) of small particles surrounding the invisible secondary companion.Comment: 8 figures, 9 pages, Astronomy and astrophysics in prin

Broadband optical gain via interference in the free electron laser: principles and proposed realizations

We propose experimentally simplified schemes of an optically dispersive interface region between two coupled free electron lasers (FELs), aimed at achieving a much broader gain bandwidth than in a conventional FEL or a conventional optical klystron composed of two separated FELs. The proposed schemes can {\it universally} enhance the gain of FELs, regardless of their design when operated in the short pulsed regime

Possible Method for Measuring the Proton Form Factors in Processes with and without Proton Spin Flip

The ratio of the squares of the electric and magnetic proton form factors is shown to be proportional to the ratio of the cross sections for the elastic scattering of an unpolarized electron on a partially polarized proton with and without proton spin flip. The initial proton at rest should be polarized along the direction of the motion of the final proton. Similar results are valid for both radiative $ep$ scattering and the photoproduction of pairs on a proton in the Bethe--Heitler kinematics. When the initial proton is fully polarized in the direction of the motion of the final proton, the cross section for the $ep \to ep$ process, as well as for the $ep \to ep \gamma$ and $\gamma p \to e \bar e p$ processes, without (with) proton spin flip is expressed only in terms of the square of the electric (magnetic) proton form factor. Such an experiment on the measurement of the cross sections without and with proton spin flip would make it possible to acquire new independent data on the behavior of $G_E^2(Q^2)$ and $G_M^2(Q^2)$, which are necessary for resolving the contradictions appearing after the experiment of the JLab collaboration on the measurement of the proton form factors with the method of polarization transfer from the initial electron to the final proton.Comment: 7 pages, revtex

One-dimensional Model of a Gamma Klystron

A new scheme for amplification of coherent gamma rays is proposed. The key elements are crystalline undulators - single crystals with periodically bent crystallographic planes exposed to a high energy beam of charged particles undergoing channeling inside the crystals. The scheme consists of two such crystals separated by a vacuum gap. The beam passes the crystals successively. The particles perform undulator motion inside the crystals following the periodic shape of the crystallographic planes. Gamma rays passing the crystals parallel to the beam get amplified due to interaction with the particles inside the crystals. The term `gamma klystron' is proposed for the scheme because its operational principles are similar to those of the optical klystron. A more simple one-crystal scheme is considered as well for the sake of comparison. It is shown that the gamma ray amplification in the klystron scheme can be reached at considerably lower particle densities than in the one-crystal scheme, provided that the gap between the crystals is sufficiently large.Comment: RevTeX4, 22 pages, 4 figure

Unusual Lattice Parameters Behavior for La1.9Ca0.1NiO4+δ at the Temperatures below Oxygen Loss

In this work, we studied the structural features of La1.9Ca0.1NiO4.11, which is considered a promising cathode material for intermediate temperature solid-oxide fuel cells (IT-SOFC). The effect of different pretreatments on the structural characteristics of the sample was studied using X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) in order to elucidate the origin of a peculiar change of lattice parameters observed earlier during in situ XRD studies. The XRD studies have shown that anisotropic broadening for reflections with a high Miller index l appears after tempering of a quenched (from 1100◦C) sample at 250◦C. This temperature is too low for the release/incorporation of oxygen into the structure but is sufficient for oxygen migration inside the structure. The HRTEM assisted us in revealing differences in the defect structure after different pretreatments. Based on obtained results, the following possible explanation was proposed. Observed additional microstrains and non-oriented planar defects as well as a decrease in the coherent scattering region size in the [00l] direction are caused by the non-homogeneous redistribution of interstitial oxygen in the structure during tempering. © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).Funding: The reported study was funded within the framework of budget project for Synchrotron radiation facility SKIF, Boreskov Institute of Catalysis. In the part of samples characterization by HRTEM technique the work was supported by the Ministry of Science and Higher Education of the Russian Federation within the governmental order for Boreskov Institute of Catalysis

Fel Potential of the High Current Erls at Bnl.

An ampere class 20 MeV superconducting Energy Recovery Linac (ERL) is under construction at Brookhaven National Laboratory (BNL) for testing concepts for high-energy electron cooling and electron-ion colliders. This ERL prototype will be used as a test bed to study issues relevant for very high current ERLs. High average current and high performance of electron beam with some additional components make this ERL an excellent driver for high power far infrared Free Electron Laser (FEL). A possibility for future up-grade to a two-pass ERL is considered. We present the status and our plans for construction and commissioning of the ERL. We discus a FEL potential based on electron beam provided by BNL ERL

VoIP security - attacks and solutions

Voice over IP (VoIP) technology is being extensively and rapidly deployed. Flexibility and cost efficiency are the key factors luring enterprises to transition to VoIP. Some security problems may surface with the widespread deployment of VoIP. This article presents an overview of VoIP systems and its security issues. First, we briefly describe basic VoIP architecture and its fundamental differences compared to PSTN. Next, basic VoIP protocols used for signaling and media transport, as well as defense mechanisms are described. Finally, current and potential VoIP attacks along with the approaches that have been adopted to counter the attacks are discussed