Experimental demonstration of optical stochastic cooling.

Particle accelerators and storage rings have been transformative instruments of discovery, and, for many applications, innovations in particle-beam cooling have been a principal driver of that success1. Stochastic cooling (SC), one of the most important conceptual and technological advances in this area2-6, cools a beam through granular sampling and correction of its phase-space structure, thus bearing resemblance to a 'Maxwell's demon'. The extension of SC from the microwave regime up to optical frequencies and bandwidths has long been pursued, as it could increase the achievable cooling rates by three to four orders of magnitude and provide a powerful tool for future accelerators. First proposed nearly 30 years ago, optical stochastic cooling (OSC) replaces the conventional microwave elements of SC with optical-frequency analogues and is, in principle, compatible with any species of charged-particle beam7,8. Here we describe a demonstration of OSC in a proof-of-principle experiment at the Fermi National Accelerator Laboratory's Integrable Optics Test Accelerator9,10. The experiment used 100-MeV electrons and a non-amplified configuration of OSC with a radiation wavelength of 950 nm, and achieved strong, simultaneous cooling of the beam in all degrees of freedom. This realization of SC at optical frequencies serves as a foundation for more advanced experiments with high-gain optical amplification, and advances opportunities for future operational OSC systems with potential benefit to a broad user community in the accelerator-based sciences.

Orientational effects in the polarized absorption spectra of molecular aggregates.

We present a detailed theoretical analysis of polarized absorption spectra and linear dichroism of cyanine dye aggregates whose unit cells contain two molecules. The studied threadlike ordered system with a molecular exciton delocalized along its axis can be treated as two chains of conventional molecular aggregates, rotated relative to each other at a certain angle around the aggregate axis. Our approach is based on the general formulas for the effective cross section of light absorption by a molecular aggregate and key points of the molecular exciton theory. We have developed a self-consistent theory for describing the orientational effects in the absorption and dichroic spectra of such supramolecular structures with nonplanar unit cell. It is shown that the spectral behavior of such systems exhibits considerable distinctions from that of conventional cyanine dye aggregates. They consist in the strong dependence of the relative intensities of the J- and H-type spectral bands of the aggregate with a nonplanar unit cell on the angles determining the mutual orientations of the transition dipole moments of constituting molecules and the aggregate axis as well as on the polarization direction of incident light. The derived formulas are reduced to the well-known analytical expressions in the particular case of aggregates with one molecule in the unit cell. The calculations performed within the framework of our excitonic theory combined with available vibronic theory allow us to quite reasonably explain the experimental data for the pseudoisocyanine bromide dye aggregate.

Multilocus Analysis of Phylogenetic Relationships in the Crocidura suaveolens Sensu Lato Species Complex: A Comparison with Mitochondrial Data.

Multilocus analysis was for the first time used to study the phylogeny of the Crocidura suaveolens s. l. species complex. Sequencing data for 16 nuclear genes indicated that several distinct forms exist within the species complex. The structure of the complex did generally not contradict its mitochondrial phylogeny. Siberian shrew showed certain specificity of the nuclear genome, but the degree of its genetic differentiation did not correspond to the species level. Relationships of Crocidura aff. suaveolens from South Gansu and Sichuan with other forms of the species complex were clarified. Shrews from Buryatia and Khentei also belong to this form, but their mtDNA apparently introgressed from C. shantungensis in the past. Hybridization of C. suaveolens s. str. with C. aff. suaveolens and C. güeldenstaedtii occurred recently. Due to multiple introgression events in the history of C. suaveolens s. l., a far larger set of loci is necessary for the analysis of the phylogenetic relationships between its forms.

Phylogeny of the Dipus sagitta Species Complex by Nuclear Gene Sequences.

The northern three-toed jerboa Dipus sagitta had long been considered to be a single polytypic species. High genetic diversity of D. sagitta was earlier revealed on the basis of several mitochondrial and nuclear genes, and several separate species were hypothesized to occur within the taxon. However, the relationships between phylogenetic lineages have not been established because of the small sample size of nuclear genes. In the present work, a far larger set of nuclear DNA loci was used, and thus, a higher resolution of the phylogenetic tree was achieved for ten D. sagitta forms. The structure revealed for the species mainly confirmed the topology and relationships of the mtDNA lineages. Yet the mitochondrial and nuclear phylogenies were not completely consistent. Some of the D. sagitta genetic lineages were therefore assumed to be a product of reticular evolutionary processes. The taxon was concluded to be the diverse species complex D. sagitta sensu lato, in which long-diverged lineages are not always reproductively isolated.

[Revision surgery after previous spinal decompression and fusion for lumbar spinal stenosis]. / Revizionnye khirurgicheskie vmeshatel'stva posle dekompressivno-stabiliziruyushchikh operatsii po povodu poyasnichnogo stenoza.

Nowadays, vertebral stenosis is the most common indication for surgical treatment in patients over 65 years old in spine surgery. According to the literature, there are conflicting data on the incidence and indications for revision surgery after previous spinal decompression and fusion for lumbar spinal stenosis. OBJECTIVE: To evaluate the incidence and indications for revision surgery after previous spinal decompression and fusion for lumbar spinal stenosis. MATERIAL AND METHODS: A retrospective single-center study enrolled 1233 patients with lumbar spine stenosis who underwent spinal decompression and fusion surgery between 2014 and 2018. The number and causes of readmission were evaluated. RESULTS: There were 164 readmissions. Revision surgery at the same level was performed in 63 patients (38.4%), at the higher level - 72 (43.9%), at the lower level - in 29 (17.7%) patients. The most common indication for readmission was spondyloarthrosis with facet joint syndrome (94 (57.3%) patients). The second common complication was pseudoarthrosis (26 (15.9%) patients). These ones comprised 2.1% of all patients with lumbar spine stenosis. CONCLUSION: The most common indication for readmission was adjacent segment degeneration. The most severe complications requiring complex and even multiple stage revision surgery were pseudoarthrosis and postoperative spondylodiscitis. Causes of readmission are significantly changing at different periods after surgery.

Manifestation of the anisotropic properties of the molecular J-aggregate shell in the optical spectra of plexcitonic nanoparticles.

The theoretical studies of light absorption and scattering spectra of the plexcitonic two-layer triangular nanoprisms and three-layer nanospheres are reported. The optical properties of such metal-organic core-shell and core-double-shell nanostructures were previously explained within the framework of pure isotropic models for describing their outer excitonic shell. In this work, we show that the anisotropy of the excitonic shell permittivity can drastically affect the optical spectra of such hybrid nanostructures. This fact is confirmed by directly comparing our theory with some available experimental data, which cannot be treated using conventional isotropic shell models. We have analyzed the influence of the shell anisotropy on the optical spectra and proposed a type of hybrid nanostructure that seems the most convenient for experimental observation of the effects associated with the anisotropy of the excitonic shell. A strong dependence of the anisotropic properties of the J-aggregate shell on the material of the intermediate spacer layer is demonstrated. This allows proposing a new way to effectively control the optical properties of metal-organic nanostructures by selecting the spacer material. Our results extend the understanding of physical effects in optics of plexcitonic nanostructures to more complex systems with the anisotropic and multi-excitonic properties of their molecular aggregate shell.

Amorphization and nanocrystal formation in a Pd-Ni-Cu-P alloy after cooling under different conditions.

Structure formation during solidification of a Pd-Ni-Cu-P melt is studied. It is demonstrated that changes in the heat transfer conditions lead to a nonlinear change in the characteristics of the structure. The article presents the regimes of cooling the samples and the results of their structure and composition studies. It is found that a decrease in the cooling rate of the alloy leads to an increase in the size, proportion and composition of nanoinclusions in an amorphous matrix. X-ray diffraction method, electron probe microanalysis, transmission microscopy and scanning calorimetry are used for samples characterization. This article is part of the theme issue 'Transport phenomena in complex systems (part 2)'.

Continuous absorption and emission of light by the heteronuclear rare gas (ArXe)+ and (KrXe)+ ions.

Studies of radiative transitions between ground and charge transfer excited terms of heteronuclear rare-gas (ArXe)+ and (KrXe)+ ions with small and moderate dissociation energies (D0 ArXe+ =179 and D0 KrXe+ =389 meV) are reported. Potential energy curves and dipole transition matrix elements are evaluated using ab initio calculations based on the CASSCF method followed by the NEVPT2 treatment and perturbative description of relativistic effects as implemented in the ORCA suite. We develop an efficient approach for the calculations of Boltzmann-averaged cross sections, rate constants, and absorption and emission coefficients associated with the integral contributions of bound-bound and bound-free transitions from a manifold of rovibrational states of the (RgXe)+ ion. A similar approach is used for the description of the free-free and free-bound transitions between different electronic terms of a quasimolecular (RgXe)+ ion temporarily formed during a collision of Ar or Kr atoms with Xe+ ions. Our method is based on the quantal version of the theory of non-adiabatic transitions in molecular and quasimolecular systems combined with the approximation of a quasicontinuum for rovibrational energy levels. This allowed us to obtain a semianalytic expression for the integral absorption properties particularly relevant at elevated temperatures. We perform a comprehensive analysis of the identified radiative processes in local thermodynamic equilibrium plasmas of rare gas Rg/Xe mixtures containing both atomic, Xe+, and molecular, RgXe+, ions and determine their role in the formation of the absorption and emission spectra in a wide range of wavelengths and gas temperatures. The results obtained are in good agreement with the available experimental data.

Single-pass Cr:ZnSe amplifier for broadband infrared undulator radiation.

An amplifier based on a highly-doped chromium zinc-selenide (Cr:ZnSe) crystal is proposed to increase the pulse energy emitted by an electron bunch after it passes through an undulator magnet. The primary motivation is a possible use of the amplified undulator radiation emitted by a beam circulating in a particle accelerator storage ring to increase the particle beam's phase-space density-a technique dubbed optical stochastic cooling (OSC). This paper uses a simple four energy level model to estimate the single-pass gain of Cr:ZnSe and presents numerical calculations combined with wave-optics simulations of undulator radiation to estimate the expected properties of the amplified undulator wave-packet.

Spectral-band replication phenomenon in a single pair of hybrid metal-organic nanospheres and nanodisks caused by plexcitonic coupling.

We study an unusual effect of spectral-band replication in the optical spectra of dimers, consisting of spherical nanoparticles or nanodisks with a silver core and a J-aggregate shell of TDBC-dye. It consists in the emergence of a doubled number of plexcitonic spectral bands compared to the case of a plasmonic dimer and in narrow peaks associated with the resonances of the J-aggregate shell. The plexcitonic bands can be divided into two groups: the "original" bands, accurately reproducing plasmonic peaks, and their "replicas," with a specific mutual arrangement and intensity distributions. The effect is interpreted using the multi-state effective Hamiltonian model describing a strong coupling between the quasi-degenerate Frenkel excitonic modes in the organic shells and multiple plasmonic modes in the pair of Ag-cores. We quantitatively explain some available experimental data on the optical properties of nanodisks and suggest a way for the observation of the replication effect. Our results extend the understanding of the nature of plexcitonic coupling to more complex systems compared to individual metal/J-aggregate nanoparticles.

[Virus specific antibody - based remedies for the urgent prevention and treatment of Ebola virus disease].

The Ebola virus (member of Ebolavirus genus Filoviridae family) is the etiologic agent of extremely hazard human disease with high mortality rates (up to 90%). The most important components of spectrum of therapeutics for special prophylactic and current of disease, caused by Ebola virus, are prepares, based on virus specific antibodies (convalescent's plasma, geterologic immunoglobulins, monoclonal antibodies. The use of different class therapeutics, based on virus specific antibodies, the possible improvements of its composition and strategy of its application for special prophylactic and current of disease, caused by Ebola virus, are considered in this review.

PRO-INFLAMMATORY EFFECTS OF EXPERIMENTAL HYPERTHYROIDISM IN COLON OF MICE (IMMUNOHISTOCYTOCHEMICAL STUDY).

Thyroid hormones can exert responses in various immune cells affecting several inflammation-related processes. The interactions between the endocrine and immune systems have been shown to contribute to pathophysiological conditions. Aim of study - to answer the question if hyper- or/and hypothyroid state can be as provoking factor for inflammation in colon. The study was performed on 60 mature male mice of the inbred line C3H-A. On male mice was reproduced a model of experimental hyperthyroidism and hypothyroidism by oral intake of L-thyroxin and propylthyouracil, accordingly. By the 22nd week of the experiment all animals were sacrificed. The rectum was removed for histo- and immunocytochemical examination. In histological examination in hyperthyroid group the hypertrophy of the mucous membrane of the colon is detected. Simultaneously the frequency of cell mitosis is increased. Among the epithelium glands of the colon can clearly be seen apoptotic bodies. Moderate or expressed infiltration by lymphocytes and plasma cells is elucidated in mucous membrane of colon relatively to mucous membrane of colon of euthyroid group i.e. control one. In hyporthyroid group the hyportrophy of the mucous membrane of the colon was detected. The lymphocytic infiltration is not found. In immunocytochemical examination the frequency of CD20 and CD56 positive cells was significantly higher (>23%) in cytological preparation of membrane mucous of colon from hyperthyroid mice (p<0.01). Meanwhile CD20 and CD56 positive cells were detected in single cases in cytological preparation of membrane mucous of colon from hypothyroid mice. The same observation was done for healthy membrane mucous from control (euthyroid) group. It is possible that the thyroid status is one of the factors modulating the inflammation. This discussion is far from over, because it is unclear whether prolonged hyperthyroidism can actually activate pro-inflammatory reactions, which subsequently, in turn, activate carcinogenesis.

[Periodontal diseases and complicated pregnancy]. / Bolezni parodonta i oslozhnennoe techenie beremennosti.

PURPOSE: Based on the datas available in the modern literature, to conduct a study on the effect of dental diseases on the course of pregnancy and outcome; mainly, the impact of periodontal disease on the low birth weight of the newborn and premature birth. MATERIAL AND METHODS: This article is based on the study of materials from foreign and domestic studies found in the databases Pubmed and Elibrary. Literature data were used for the last 15 years. RESULTS: The majority of pregnant women who are not receiving due dental examination and suffering with those or other diseases of the oral cavity have an unfavorable outcome of pregnancy, including premature births and low weight of the premature newborn. The role of the chronic effect of oral microorganisms Porphyromonas gingivalis (P. gingivalis) and Fusobacterium nudeatum, as well as local increase in prostaglandin E2 (PGE2) and tumor necrosis factor (TNF-α), in the implementation of the inflammatory reaction leading to a decrease in the weight of the fetus by 15-18%. CONCLUSION: Due to the conducted research it was established that periodontal diseases and other infectious diseases of the oral cavity negatively affect the course of pregnancy and its outcome. The main problems were the lack of women's health education in terms of preparing for pregnancy and sanitation of foci of infection in the oral cavity both before pregnancy and at the time, as well as poor access to the dentist and not receiving proper prevention and, if necessary, treatment of oral diseases.

Optical properties of molecular nanocrystals consisting of J-aggregates of anionic and cationic cyanine dyes.

We report results of experimental studies of the photoabsorption, photoluminescent and photoelectric properties of a new type of multilayer molecular nanocrystals, consisting of highly ordered J-aggregates of one anionic and two cationic J-aggregates of cyanine dyes. In contrast to conventional J-aggregated dyes the multichromic nanocrystals synthesized in this work, are capable of efficient light absorption in three excitonic bands of the visible and near-IR spectral ranges. The spectral peak positions in the absorption bands can be controlled by appropriately selecting a set of dyes a molecular crystal is made of. Our investigations of the photoelectric properties of multichromic crystals have shown that each of them can potentially be used as a photosensitive layer of a photocell with photoconductivity in three peaks of excitonic absorption. The synthesized nanocrystals are attractive for the creation of thin-film organic photodetectors with a large photosensitive area and varied photoabsorption spectra, excitonic waveguides and for some other applications in organic and hybrid photonics and optoelectronics.

The Structural Arrangement and Relative Abundance of Aliphatic Units May Effect Long-Wave Absorbance of Natural Organic Matter as Revealed by 1H NMR Spectroscopy.

The objective of this study was to shed light on structural features which underlay intensity of long wave absorbance of natural organic matter (NOM) using 1H NMR spectroscopy. For this purpose, a set of the NOM samples was assembled from arctic and nonarctic sampling sites (the Kolyma river basin and Moscow region, respectively). It was to ensure a substantial difference in the humification degree of the isolated organic matter-the biogeochemical proxy of the long-wave absorbance of NOM. The assembled NOM set was analyzed using solution-state 1H NMR spectroscopy. The distribution of both backbone and exchangeable protons was determined using acquisition of spectra in three different solvents. The substantially higher contribution of nonfunctionalized aliphatic moieties CHn (e.g., materials derived from linear terpenoids, MDLT) in the arctic NOM samples was revealed as compared to the nonarctic ones. The latter were characterized with the higher content of CHα protons adjacent to electron-withdrawing groups which belong to carboxyl rich alicyclic moieties (CRAMs) or to aromatic constituents of NOM. We have calculated a ratio of CHn to CHα protons as a structural descriptor which showed significant inverse correlation to intensity of long wave absorbance assessed with a use of E4/ E6 ratio and the slope of absorption spectrum. The steric hindrance of aromatic chromophoric groups of the NOM ensemble by bulky nonfunctionalized aliphatic moieties (e.g., MDLT) was set as a hypothesis for explanation of this phenomenon. The bulky aliphatics might increase a distance between the interacting groups resulting in inhibition of electronic (e.g., charge-transfer) interactions in the NOM ensemble. The obtained relationships were further explored using Fourier transform mass spectrometry as complementary technique to 1H NMR spectroscopy. The data obtained on correlation of molecular composition of NOM with 1H NMR data and optical properties were very supportive of our hypothesis that capabilities of NOM ensemble of charge transfer interactions can be dependent on structural arrangement and relative abundance of nonabsorbing aliphatic moieties.

Effect of Glutamine Synthetase Gene Overexpression in Birch (Betula pubescens) Plants on Auxin Content and Rooting in vitro.

The effects of transformation of downy birch (Betula pubescens Ehrh.) with the GS1 gene encoding the cytosolic form of glutamine synthetase on the rooting of plants in vitro was studied. The transgenic plants had an elevated content of glutamine as well as glutamic and aspartic acids and rooted more rapidly than the control plants. Rooting on a medium containing the glutamine synthetase inhibitor phosphinothricin prevented the accumulation of auxin in birch plants carrying the GS1 gene, indicating the involvement of this enzyme in raising the level of auxins in the transgenic plants. The correlation between the increase in the auxin levels in the transgenic plants carrying the glutamine synthetase gene and the increase in the rooting rate is shown for the first time.

Is the Center of Origin of Long-tailed Hamster Cricetulus longicaudatus Milne-Edwards 1867 (Rodentia, Cricetidae) Located in Tibet?

First data on morphological and mitochondrial variation in the long-tailed hamster Cricetulus longicaudatus is presented. In contrast to genetically monomorphic populations of Mongolia and Tuva, the northeastern part of the Qinghai-Tibetian Plateau was found to harbor several divergent mtDNA lineages. This pattern suggests a recent expansion of the long-tailed hamster to the northern part of its recent range, which started from Tibet, presumably, in the late Middle Pleistocene. Several populations from the northern edge of the species range were found to be morphologically but not genetically distinct. The apparent disagreement between genetic and morphological data can be explained by rapid morphological evolution in peripheral isolates.

[Surgical treatment of a patient presenting with an infected aortofemoral bifurcation prosthesis]. / Khirurgicheskoe lechenie bol'nogo s infitsirovannym aorto-bedrennym bifurkatsionnym protezom.

Described herein is a clinical case report regarding successive treatment of a patient presenting with total infection of an aortofemoral bifurcation vascular prosthesis and a purulent fistula in the left iliac-inguinal region. The patient was subjected to removal of the infected aortofemoral bifurcation prosthesis, followed by autovenous aortofemoral bifurcation prosthetic repair. There were no pyo-haemorrhagic complications in the postoperative period. The wounds of the femurs and in the inguinal regions healed with second intention. Check-up computed tomography performed 3 months postoperatively demonstrated satisfactory patency of the autovenous graft and no retroperitoneal formations.

[The use of genetic engineering constructions as control samples on evaluation of diagnostic kits for reveal of rna of hazard and extremely hazard agents of virus infections by reverse transcription - polymerase chain reaction.]

The reverse transcription - polymerase chain reaction method (RT-PCR) has leading position on diagnostic infections, caused by RNA-containing viruses. This method presents severe requirements to carrying out of everybody stages of analysis (extraction of nucleic acid, carry out reverse transcription, amplification of DNA). It is necessary to account the possibility of false positive or false negative results appearance. The use on RT-PCR only positive (PCS) and negative (NCS) control samples is insufficient for the control of stages of RNA extraction and reverse transcription. That is way there is necessity the construction of inner control sample (ICS) to control of these stages. The main goal of present is the ground of use genetic engineering constructions (GEC) as control samples (PCS and ICS) on evaluation of diagnostic kits for reveal of RNA of hazard and extremely hazard agents of virus infections by RT-PCR. The vector recombinant plasmids, containing the insertion of cDNA of agent´s genomic RNA are used as PCS, RNA was packed in membrane protein of MS2 bacteriophage, is used as ICS. It is demonstrated that ICS does no influence on sensitivity of RT-PCR both for use of native agents and for use of synthetic nucleic acids of Ebola, Marburg, Lassa, Machupo, Venezuelan encephalitis equine (VEE), Rift Valley fever and rabies viruses. The possibility of use of PCS and ICS for standardization of diagnostic kits is discussed.

[Microsatellite loci variation and investigation of gene flow between two karyoforms of Cricetulus barabensis sensu lato (Rodentia, Cricetidae)].

We examine the diversity of six microsatellite loci and partial RAG1 exon of "barabensis" and "pseudogriseus" karyoforms in Cricetulus barabensis sensu lato species complex. A total of 435 specimens from 68 localities ranging from Altai to the Far East are investigated. The results of the population structure analysis (factor analysis and NJ tree based on Nei genetic distances) support subdivision into two well-differentiated clusters corresponding to the two karyoforms. These karyoforms are also well differentiated by the level of microsatellite variability. In several "barabensis" specimens, we found microsatellite alleles that are common in "pseudogriseus" populations but are otherwise absent in "barabensis." Most of these specimens originate from a single population in one of the zones of potential contact between karyoforms, Kharkhorin in Central Mongolia. These molecular results are consistent with previously published karyological data in suggesting that rare hybridization events between the two chromosomal races occur in nature.