SWAP and Fredkin gates for OAM optical beams via the sandwich of anisotropic optical fibers.

We study the propagation of circularly-polarized optical vortices of higher order topological charges ℓ ≥ 2 in a sandwich of multihelical - anisotropic - multihelical fibers on the basis of the Jones formalism for modes with orbital angular momentum. We demonstrate that such a system can operate as the all - fiber two - bit SWAP as well as universal tree - bit controlled-SWAP (Fredkin) gates over states of optical vortices, in which the mode radial number carries the control bit, while circular polarization and topological charge are the controlled bits.

Generation of optical vortices in non-parity-time-symmetric chiral-core optical fibers.

In this Letter, we have studied the effect of losses and gains on generation of optical vortices (OVs) in a chiral fiber with an l-fold rotational symmetric core. Studying both unequal attenuations and symmetric loss-gain cases for core and orbital angular momentum (OAM) modes, we show that losses may play a constructive role in generation of OVs from a Gaussian input. We study the processes of field evolution at the exceptional point (EP). We show that at the EP any superposition of the fundamental mode and l-charge OV evolves in the limit into an equal-weighted superposition of such fields that forms a special attractor mode with average l/2 OAM per photon. At the generalized Poincare sphere, such a mode is represented by the OAM black hole in analogy with the spin black hole introduced in [Optica3, 1025 (2016)OPTIC82334-253610.1364/OPTICA.3.001025].

Optical vortices and orbital angular momentum in strongly coupled optical fibers.

We have studied the effect of strong coupling on the propagation of optical vortices (OVs) and evolution of their orbital angular momentum (OAM) in parallel multimode optical fibers. Based on the perturbation theory that goes beyond the limits of weak orthogonality approximation we have established that strong coupling does not lead to alteration of the structure of supermodes as compared to the case of weak coupling. The strong coupling affects only the propagation constants of such supermodes, which we have found analytical expressions for. We have also studied the evolution of OVs and emphasized the difference between the powers stored in partial OVs and powers located at the fiber cores. We have studied OAM in such fibers, as well as corrections to the total OAM due to interference effects and shown that the influence of such effects on forming the total OAM under strong coupling is negligible. We have also demonstrated that in such systems it is sufficient to take account only of the coupling of OVs with equal by modulus topological charges, whereas other types of coupling are negligible.

Amplification of optical activity in a fiber loop resonator.

In this paper, we have theoretically studied an effective amplification of optical activity by a fiber loop resonator. We propose a scheme in which an optically active element is placed in the loop segment of the resonator. Assuming that the coupling in the resonator is polarization-independent, we have shown that initially small polarization plane rotation, which arises due to the optically active element, can be significantly amplified by tuning the resonator's closed-path phase. We have also studied the influence of losses on the amplification of optical activity. We have shown that the maximal amplification takes place under the condition of critical coupling, at which the attenuation parameter is equal to the resonator's effective reflection coefficient. We have also studied effective dichroism in such a system and shown the relevance of a critical coupling regime to that effect.

Transmission of optical vortices through fiber loop resonators.

In this Letter, we study the propagation of optical vortices (OVs) through the loop resonator (LR) on a multimode fiber. We demonstrate the existence of a special resonance, which is in the inversion of the topological charge of the transmitted OV. Near the resonance, the output orbital angular momentum (OAM) is sensitive to wavelength-scale variations of the LR's optical path length, which can be used for super-efficient OAM control. We also show the feasibility of a combined wavelength and OAM division multiplexing in comb filters on such LRs.

Revised model of acousto-optic interaction in optical fibers endowed with a flexural wave.

We propose a novel model of the acousto-optic interaction in circular fibers endowed with the lowest-order flexural acoustic wave that is based on the actual distribution of the acoustically induced displacement vector. The corresponding expression for the fiber's permittivity is derived and compared with the commonly used one. The resonance optical fiber modes and the propagation constants are found. It is predicted that the lengths of the well-known acoustically driven mode conversion LP0,n→LP1,n' should be slightly different for the x- and y-polarized incident fundamental modes. Moreover, we unveil a new polarization-dependent mode conversion in which the azimuthal mode number ℓ, as well as the optical frequency of the generated standard fiber mode LPℓ,n' , is governed by the linear polarization direction of the incident zero-order beam LP0,n.

Natural infection of captive cynomolgus monkeys (Macaca fascicularis) with hepatitis E virus genotype 4.

Data on natural HEV infection of infection in monkeys are limited. We report a case of hepatitis E virus genotype 4 infection in captive non-human primates (cynomolgus monkeys) imported from Vietnam. Phylogenetic analysis demonstrated that HEV infection was not the result of spillover from single source of infection, but rather the persistent circulation of HEV-4 among cynomolgus monkeys or multiple infections by related strains from a human or swine reservoir.

Formation of Alcohol Motivation in Monkeys (Macaca mulatta) Kept in Isolation.

The effects of environmental factors (flavors, different ethanol concentration, alcoholic deprivation, and food reinforcement) on the formation of alcohol motivation was studied in rhesus macaques (Macaca mulatta, n=6). Motivation for alcohol intake was induced in two stages: initiation (sessions 1-160) and formation of motivation (sessions 161-516). Monkeys preferred multifruit flavor and 4% ethanol solution, while ethanol deprivation did not stimulate alcohol consumption. The pronounced individual differences in the pattern of alcohol motivation were revealed: the intake of 4% ethanol solution ranged from 0.21±0.03 to 0.43±0.06 g/kg without food reinforcement and increased from 0.78±0.03 to 1.22±0.09 g/kg with food reinforcement. The results suggest that the proposed method is valid and can be used as an experimental model of alcohol dependence in non-human primates.

Water Immersion as a Model of Hypogravity.

We studied the effects of hypogravity modeled by water immersion on cognitive functions and physiological parameters of monkeys. Cognitive capacities of monkeys were evaluated using computer-controlled joystick task with food reward in case of target hit. Water immersion (3 days for 3 h) affected in cognitive functions, body temperature, and blood parameters. The intensity of changes depended on the type of monkey behavior. In animals with non-aggressive behavior, the number of target hits did not decrease after water immersion, and even slightly increased. On the contrary, aggressive monkeys showed poorer test performance. Body temperature after each cycle of water immersion was decreased slightly in non-aggressive monkeys, while in aggressive animals, the changes were significant. At the same time, changes in the erythrocyte count, hemoglobin concentration, and hematocrit were significant in non-aggressive monkeys. Our results are in line with previous data performed on BION biosatellites and correspond to changes of physiological parameters in astronauts during space flights.

In Vivo Experimental Study of Biological Compatibility of Tissue Engineered Tracheal Construct in Laboratory Primates.

Biological compatibility of a tissue engineered construct of the trachea (synthetic scaffold) and allogenic mesenchymal stem cells was studied on laboratory Papio hamadryas primates. Subcutaneous implantation and orthotopic transplantations of tissue engineered constructs were carried out. Histological studies of the construct showed chaotically located filaments and mononuclear cells fixed to them. Development of a fine connective tissue capsule was found at the site of subcutaneous implantation of the tissue engineered construct. The intact structure of the scaffold populated by various cell types in orthotopic specimens was confirmed by expression of specific proteins. The results indicated biological compatibility of the tissue engineered construct with the mesenchymal stem cells; no tissue rejection reactions were recorded; simulation of respiratory disease therapy on Papio hamadryas proved to be an adequate model.

Functional Parameters of Physiological Systems of Laboratory Primates after Administration of Doxorubicin and Transplantation of Mesenchymal Stem Cells.

We studied physiological parameters of rhesus monkeys after administration of anthracycline antibiotic doxorubicin. Intravenous administration of the drug caused intoxication manifested in in an abrupt body weight loss, baldness, vomiting, and exicosis. Intoxication in monkeys determined by the damaging effects of doxorubicin on organs and tissues is also characterized by significant changes in the blood: leukopenia, thrombocytopenia, neutropenia, monocytopenia, lymphocytosis, and a sharp drop of CD20+ B cell content. The total protein and albumin content in the blood significantly decreased. A sharp increase in C-reactive protein was also accompanied by an increase in activity of proinflammatory cytokine IL-6. Transplantation of mesenchymal stem cells in some cases can significantly alleviate doxorubicin-induced damage to organs and maintain normal clinical status of monkeys after two injections of the drug. Late transplantation of stem cells does not have a protective effect and does not protect the animals from the damaging effects of doxorubicin. We found that the protective effect of mesenchymal stem cells depends on the dose of the drug, total number of cells, and the time of their transplantation. It should be noted that human and monkey mesenchymal stem cells produce similar regenerative effects, at least in the doxorubicin toxicity model.

Use of Mesenchymal Stem Cells for Possible Repair of Doxorubicin-Damaged Organs and Tissues in Experimental Monkeys.

Three injections of doxorubicin to rhesus macaques cause severe intoxication, characterized by anemia, cachexia, and degeneration of the viscera. The life span of monkeys injected with the drug and receiving after 24 h mesenchymal stem cell transplantation varied from 96 to 120 days in comparison with 50-74 days in animals receiving stem cells before doxorubicin. Controls received doxorubicin and saline; the lifespan of one monkey was 24 days, of the other - 1 year and 8 months. The increase in activity of proinflammatory cytokine IL-6 was paralleled by an increase in the level of C-reactive protein.

Resonance optical activity in multihelicoidal optical fibers.

We have studied the effect of optical activity (OA) in optical fibers with multihelical distribution of refractive index profiles near the resonance wavelength, at which the conversion of an incident Gaussian beam into an optical vortex (and vice versa) takes place. We have shown that at such a wavelength the polarization vector of the input Gaussian beam rotates within the fiber at an average rate proportional to the difference in propagation constants of left- and right-circularly polarized optical vortices with the same topological charge. We also show that for certain fiber lengths the magnitude of OA can greatly exceed its average level and reach anomalously high values.

Transplantation of Simian Mesenchymal Stem Cells to Baboons with Experimentally Induced Myocardial Infarction.

Culture of mesenchymal stem cells isolated from the bone marrow of primates by their characteristics met the requirements of stem cells. It was shown that transplantation of allogeneic mesenchymal stem cells (2 million cells per 1 kg body weight) immediately after ligation of the left anterior descending coronary artery between the middle and upper thirds led to neovascularization and capillarization of the ischemic myocardium.

[To the 50th anniversary of the discovery of the simian hemorrhagic fever and SHF virus].

The results of the study of SHF and virus SHF for the last period since their discovery are summed up. It was established that the source of this infection fatal for Asian macaques are African monkeys--virus carriers. There is still a danger of the occurrence of epizootics in Primatological Centers at the importation of these monkeys for research. The importance of the obtained experimental SHF in macaques was emphasized. This model is unique, safe and adequate. It is necessary for further study of pathogenesis and evaluation of the means of pathogenetic therapy of HF dangerous to human health.

[Preclinical study of safety of the new pharmacological substance AV0012 to treat hepatitis C].

Pharmacological safety of a new type of HCV inhibitor, AV0012, was studied including acute, subchronic and chronic toxicity in mice, rats and monkeys. Genotoxicity was assessed using the Ames test and the chromosomal aberrations assay in the bone marrow cells of mice. It is established that AV0012 has low toxicity in SHK line mice, Wistar line rats, and monkey of Rhesus macaques species. Results obtained in the study of genetic toxicity showed that AV0012 exhibits no mutagenic activity. Data on general toxicity and mutagenicity discussed in this paper, together with data on 1 the pharmacological activity, pharmacokinetics, and metabolism published previously, allow us to consider AV0012 as a candidate drug for clinical research phase I.

[Preclinical study of AV0012 early stage inhibitor of hepatitis C virus infection: I. In vitro ADME and pharmacokinetics].

In vitro immunohistochemical investigations on the human hepatoma cell line (Huh7) infected with hepatitis C virus (HCV) strain JFH-1 showed that AV0012 compound blocks the early stages of viral infection. AV0012 also blocked viral infection spread in tissue culture through the secreted virus and through tight cell-to-cell contact. AV0012 is a specific inhibitor of HCV but not of related pestivirus, flaviviruses and other RNA-containing viruses such as bovine diarrhea (BVDV), Venezuelan equine encephalitis (strain TC-83), dengue type 2 (New Guinea), yellow fever (strain 17D), west Nile fever, parainfluenza (type 3) virus, RSV (strain A2), and Rhinovirus (type 2 strain HGP). It is established that human serum does not significantly affect the antiviral activity of AV0012 in vitro. The drug combination studies with AV0012 and interferon alpha 2a in vitro showed that the two inhibitors act additively, which makes possible the use of this combination in clinical tests. AV0012 is highly soluble and stable in aqueous solutions and murine blood plasma, has limited metabolic stability, low binding to human plasma proteins, high permeability through biological membranes, and only interacts with isoenzymes 2D6 and 3A4 of human cytochrome P450. In animal pharmacokinetic studies, AV0012 was rapidly absorbed into the blood stream upon oral administration, showed sufficiently long half-elimination times, and had high oral bioavailability that reached 92% in monkeys. Further preclinical development of AV0012 is in progress.

Studying the impact of geometrical and cellular cues on myogenesis with a skeletal muscle-on-chip.

In the skeletal muscle tissue, cells are organized following an anisotropic architecture, which is both required during myogenesis when muscle precursor cells fuse to generate myotubes and for its contractile function. To build an in vitro skeletal muscle tissue, it is therefore essential to develop methods to organize cells in an anisotropic fashion, which can be particularly challenging, especially in 3D. In this study, we present a versatile muscle-on-chip system with adjustable collagen hollow tubes that can be seeded with muscle precursor cells. The collagen acts both as a tube-shaped hollow mold and as an extracellular matrix scaffold that can house other cell types for co-culture. We found that the diameter of the channel affects the organization of the muscle cells and that proper myogenesis was obtained at a diameter of 75 µm. In these conditions, muscle precursor cells fused into long myotubes aligned along these collagen channels, resulting in a fascicle-like structure. These myotubes exhibited actin striations and upregulation of multiple myogenic genes, reflecting their maturation. Moreover, we showed that our chip allowed muscle tissue culture and maturation over a month, with the possibility of fibroblast co-culture embedding in the collagen matrix.

Helical-core fiber analog of a quarter-wave plate for orbital angular momentum.

We have studied the effect of a twist defect on the conversion of the fundamental mode (FM) into an optical vortex (OV) in a helical-core fiber (HCF). We have shown that if such a twist defect is situated in the middle of the HCF, which converts the FM into an OV, such a fiber system can continuously change the orbital angular momentum (OAM) of the output field from 0 to 1 (in a.u.). This control of the OAM is achieved by variation of the twist angle. In this action upon the OAM, this system has analogy with the quarter-wave plate, which is able to change the spin angular momentum. We also introduced the generalized Stokes parameters (SPs) and Poincaré sphere to visualize evolution of the superposition of states with zero and nonzero OAM. Connection of SPs with geometric characteristics of the location of singularity is made.

Blood glucose levels in rhesus monkeys (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis) under moderate stress and after recovery.

We evaluated normal blood glucose levels in two species of monkeys, namely rhesus monkeys (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis) kept in the Breeding Center of the Institute of Medical Primatology. The animals were either under moderate stress due to catching or after recovery of defensive and orienting reactions by habituation to the blood sampling. Based on these data, seasonal, gender- and age-dependent variations in glucose levels were found. Glucose levels in rhesus monkeys accustomed to blood sampling procedures were shown to be substantially lower compared with those in non-adapted gender- and age-matched animals.