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1.
Ter Arkh ; 95(6): 457-461, 2023 Aug 17.
Article in Russian | MEDLINE | ID: mdl-38158963

ABSTRACT

BACKGROUND: Focal segmental glomerulosclerosis (FSGS) is a primary podocytopathy characterized by primary podocyte detection and high proteinuria. The search for biomarkers and factors associated with the progression of this disease is an important task nowdays. AIM: To assess the proteomic profile of urine in patients with FSGS and to isolate urinary biomarkers of podocytopathies. MATERIALS AND METHODS: The study included 41 patients diagnosed with chronic glomerulonephritis, 27 men and 14 women. According to the morphological study, 28 patients were diagnosed with FSGS, 9 with steroid-sensitive nephrotic syndrome and 14 with steroid-resistant nephrotic syndrome. The comparison group included 13 patients with membranous nephropathy. The study of the urinary proteome was carried out by targeted liquid chromatography-mass spectrometry using multiple reaction monitoring with synthetic stable isotope labelled peptide standards. RESULTS: The main differences in the protein profile of urine were found in the subgroups of steroid-sensitive (SS) and steroid-resistant (SR) FSGS. In the FSGS SR group, at the onset of the disease, there was a high concentration of proteins reflecting damage to the glomerular filter (apo-lipoprotein A-IV, orosomucoid, cadherin, hemopexin, vitronectin), as well as proteins associated with tubulo-interstitial inflammation and accumulation of extracellular matrix (retinol- and vitamin D-binding proteins, kininogen-1, lumican and neurophilin-2). Compared with the membranous nephropathy group, FSGS patients had significantly higher urinary concentrations of carnosinase, orosomucoid, cadherin-13, tenascin X, osteopontin, and zinc-alpha-2-glycoprotein. CONCLUSION: Thus, in patients with SR FSGS, the proteomic profile of urine includes more proteins at elevated concentrations, which reflects severe damage to various parts of the nephron compared with patients with SS FSGS and membranous nephropathy.


Subject(s)
Glomerulonephritis, Membranous , Glomerulosclerosis, Focal Segmental , Nephrotic Syndrome , Male , Humans , Female , Glomerulosclerosis, Focal Segmental/diagnosis , Proteomics , Orosomucoid , Nephrotic Syndrome/diagnosis , Biomarkers , Steroids , Cadherins
2.
Opt Express ; 29(2): 2501-2520, 2021 Jan 18.
Article in English | MEDLINE | ID: mdl-33726444

ABSTRACT

We suggest a quantum description of Rayleigh light scattering on atoms. We show that an entangled state of the excited atom and the incident photon is formed during the scattering. Due to entanglement, a photon is never completely absorbed by the atom. The formation of the scattering spectrum is considered as a relaxation of incident photons to the reservoir of free space modes that are in thermal equilibrium. Additional excitations of the reservoir modes occurring during scattering are treated as scattered light. We show that even if the frequency of incident photons is incommensurate with an atomic transition frequency, the scattered light spectrum has a maximum at the frequency of incident photons. In addition, the linewidth of the scattered light is much smaller than that of the spontaneous emission of a single atom. Therefore, the process can be considered as elastic.

3.
Mol Biol (Mosk) ; 55(6): 927-943, 2021.
Article in Russian | MEDLINE | ID: mdl-34837697

ABSTRACT

Whole-genome duplication (WGD), or polyploidy, increases the amount of genetic information in the cell. WGDs of whole organisms are found in all branches of eukaryotes and act as a driving force of speciation, complication, and adaptations. Somatic-cell WGDs are observed in all types of tissues and can result from normal or altered ontogenetic programs, regeneration, pathological conditions, aging, malignancy, and metastasis. Despite the versatility of WGDs, their functional significance, general properties, and causes of their higher adaptive potential are unclear. Comparisons of whole-transcriptome data and information from various fields of molecular biology, genomics, and molecular medicine showed several common features for polyploidy of organisms and somatic and cancer cells, making it possible to understand what WGD properties lead to the emergence of an adaptive phenotype. The adaptation potential of WGDs may be associated with an increase in the complexity of the regulation of networks and signaling systems; a higher resistance to stress; and activation of ancient evolutionary programs of unicellularity and pathways of morphogenesis, survival, and life extension. A balance between the cell and organismal levels in controlling gene regulation may shift in stress towards the priority of cell survival, and the shift can lead to cardiovascular diseases and carcinogenesis. The presented information helps to understand how polyploidy creates new phenotypes and why it acts as a driving force of evolution and an important regulator of biological processes in somatic cells during ontogeny, pathogenesis, regeneration, and transformation.


Subject(s)
Gene Duplication , Genome, Plant , Evolution, Molecular , Humans , Phylogeny , Polyploidy
4.
Genomics ; 111(2): 115-126, 2019 03.
Article in English | MEDLINE | ID: mdl-29526483

ABSTRACT

The prevalence of purifying selection in the nature suggests that larger organisms bear a higher number of slightly deleterious mutations because of smaller populations and therefore weaker selection. In this work redistribution of purifying selection in favor of information genes, pathways and processes was found in primates compared with treeshrew and rodents on the ground of genome-wide analysis. The genes which are more favored in primates belong mainly to regulation of gene expression and development, in treeshrew and rodents, to metabolism, transport, energetics, reproduction and olfaction. The former occur predominantly in the nucleus, the latter, in the cytoplasm and membranes. Thus, although purifying selection is on average weaker in the primates, it is stronger concentrated on the "information technology" of life (regulation of gene expression and development). Increased accuracy of information processes probably allows escaping "error catastrophes" in spite of more complex organization, larger body size and higher longevity.


Subject(s)
Aging/genetics , Evolution, Molecular , Aging/metabolism , Animals , Cattle , Humans , Macaca , Metabolic Networks and Pathways/genetics , Mice , Mole Rats , Rats , Selection, Genetic
5.
Ter Arkh ; 92(6): 73-75, 2020 Jul 09.
Article in Russian | MEDLINE | ID: mdl-33346496

ABSTRACT

We present a case with a rare variant of glomerulonephritis, IgM nephropathy, which occurs mainly with nephrotic syndrome. The clinical features of this variant of kidney damage are characterized; the pathogenetic and the transformation of this form of nephritis into focal segmental glomerulosclerosis are discussed. The development of severe nephrotic syndrome at the beginning of the disease, the formation of secondary steroid resistance have confirmed this hypothesis and have justified the treatment with cyclosporin A aimed at the recovery of the function of the podocyte with remission of nephritis.


Subject(s)
Glomerulonephritis , Glomerulosclerosis, Focal Segmental , Nephrotic Syndrome , Cyclosporine , Humans , Immunoglobulin M , Nephrotic Syndrome/diagnosis , Nephrotic Syndrome/drug therapy
6.
Ter Arkh ; 92(12): 120-125, 2020 Dec 15.
Article in Russian | MEDLINE | ID: mdl-33720583

ABSTRACT

Rheumatic diseases relate to the group of the immunoinflammatory diseases (IID), in pathogenesis of which have a value both autoimmune and autoinflammatory processes. AIM: To present the heterogeneous pathogenesis of inflammation in IID. MATERIALS AND METHODS: It is inspected 260 patients (pts) with IID: 242 pts with systemic autoimmune diseases (SAD): 65 systemic lupus erythematosis, 50 systemic sclerosis, 127 systemic vasculitides (SV) and 18 patients with autoinflammatory diseases (AID): 8 Behcets disease, 2 periodic disease, 5 familial cold fever, 2 idiopathic lobular panniculitis and 1 relapsing polychondritis. Is carried out a study of complement, antigen of von Willebrand factor (FW:AG), antinuclear antibodies, antibodies to DNA, anti-endothelial antibodies, antibodies to topoizomeraze I (anti-Scl-70), antineutrophilic cytoplasmic antibodies (ANCA), anticardiolipin antibodies (aCL IgG and aCL IgM), cryoglobulins, VS, CRP. RESULTS: SAD were characterized by the synthesis of wide antibodies spectrum. As the basic serological marker at the screening it follows to consider antinuclear antibodies (75%). Practically in all groups it took place hypcomlemetemia with reduction of C3 and C4 complement. With systemic lupus erythematosis are revealed antibodies to DNA (71%), with ANCA-associated SV-ANCA (94%), aKL (14%); with SSD aScl-70 (17%). At Wegener granulomatosis ANCA are determined in 94% patients in the active stage. It is noted correlation ANCA with the index of the clinical activity of vasculitis. In the remaining SV groups ANCA were separated in the single cases. Cryoglobulins are noted in all patients with cryoglobulinemic vasculitis. aCL IgG and aCL IgM were the markers of antiphospholipid syndrome. Аnti-endothelial antibodies had significant oscillation spectrum. High indices FW:AG are noted with all above nosologic forms indicated, especially with Wegener granulomatosis and vasculitis hemorrhagic. Among the laboratory tests of inflammatory activity should be considered the determination of VS, CRP and FV:AG, which is also considered the marker of vascular wall defeat. Is given clinical characteristic and changes in the laboratory indices at AID: Conclusion.Isolation from the group IID of patients with AID serves as indication for a genetic study of this contingent with the approval of use for their treatment of biological therapy. Isolation from the group SAD patients with AID serves as indication for a genetic study of this contingent with the approval of use for their treatment of biological therapy.


Subject(s)
Glomerulonephritis , Granulomatosis with Polyangiitis , Lupus Erythematosus, Systemic , Antibodies, Antineutrophil Cytoplasmic , Autoimmunity , Humans , Lupus Erythematosus, Systemic/diagnosis
7.
Ter Arkh ; 92(6): 46-52, 2020 Jul 09.
Article in Russian | MEDLINE | ID: mdl-33346492

ABSTRACT

Chronic glomerulonephritis (CGN) is a disease with a steadily progressing course, which is based on inflammation with the activation of immune cells. The severity of the inflammatory reaction in the kidney tissue is determined by the balance of locally pro-inflammatory factors and protective mechanisms, which include anti-inflammatory cytokines and T-regulatory lymphocytes (Treg). The study of processes that can modulate the severity of inflammation in the kidney is of particular interest for understanding the basic patterns of CGN progression. AIM: To determine the clinical significance of the Th17, Th1, and Treg cytokines in urine to assess the activity and progression of chronic glomerulonephritis with nephrotic syndrome (NS). MATERIALS AND METHODS: The study included 98 patients with CGN 37 women and 61 men. Patients were divided into two groups according to the degree of CGN activity. Group I consisted of 51 patients with NS. In 21 subjects, a decrease in GFR60 ml/min was revealed. Group II included 47 patients with proteinuria from 1 to 3 g/day without NS. GFR60 ml/min/1.73 m2 was observed in 26 patients. A kidney biopsy was performed in 65 patients and the hystological diagnosis was verified: 20 had mesangioproliferative GN, 16 had membranous nephropathy, 18 had focal segmental glomerulosclerosis, and 11 had membranoproliferative GN. The control group consisted of 15 healthy people. The levels of IL-6, IL-10, IL-17, tumor necrosis factor a (TNF-a) in the urine were determined using enzyme-linked immunosorbent assay. The number of FoxP3-positive cells in the inflammatory interstitial infiltrate of the cortical layer was determined in 39 patients (in a biopsy sample in a 1.5 mm2 area). RESULTS: In group of patients with CGN, there was an increase in the levels of Th17, Th1, and Treg cytokines in urine TNF-a and IL-10 compared with healthy individuals. An increase in the levels of IL-6 in the urine of patients with high clinical activity of CGN (with NS and renal dysfunction) was more pronounced than in patients with NS and normal renal function. There was a decrease in the number of Treg cells in the interstitium of the kidney and a decrease in the production of anti-inflammatory IL-10 in CGN patients with NS, compared with patients without NS. The most pronounced changes in the cytokine profile were observed in patients with FSGS with an increase in pro-inflammatory cytokines and a decrease in Treg in the kidney tissue/anti-inflammatory IL-10 in the urine. CONCLUSION: An imbalance of cytokines characterized by an increased levels of pro-inflammatory IL-17, IL-6, TNF-a, and a reduced levels of anti-inflammatory IL-10 and T-regulatory cells in the kidney tissue is noted in patients with NS, especially with FSGS. Imbalance of cytokines reflects the high activity of CGN and the risk of the progression of the disease.


Subject(s)
Glomerulonephritis , T-Lymphocytes, Regulatory , Chronic Disease , Cytokines , Female , Humans , Male , Proteinuria , Th17 Cells
8.
Phys Rev Lett ; 122(15): 153905, 2019 Apr 19.
Article in English | MEDLINE | ID: mdl-31050521

ABSTRACT

We propose a method for increasing Raman scattering from an ensemble of molecules by up to 4 orders of magnitude. Our method requires an additional coherent source of IR radiation with the half-frequency of the Stokes shift. This radiation excites the molecule electronic subsystem that in turn, via Fröhlich coupling, parametrically excites nuclear oscillations at a resonant frequency. This motion is coherent and leads to a boost of the Raman signal in comparison to the spontaneous signal because its intensity is proportional to the squared number of molecules in the illuminated volume.

9.
Biochemistry (Mosc) ; 84(11): 1247-1255, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31760915

ABSTRACT

Fo×F1-ATPases of mitochondria, chloroplasts, and microorganisms catalyze transformation of proton motive force (the difference between the electrochemical potentials of hydrogen ion across a coupling membrane) to the free energy of ATP phosphoryl potential. It is often stated that Fo×F1-ATPases operate as reversible chemo-mechano-electrical molecular machines that provide either ATP synthesis or hydrolysis depending on particular physiological demands of an organism; the microreversibility principle of the enzyme catalysis is usually taken as a dogma. Since 1980, the author has upheld the view that the mechanisms of ATP synthesis and hydrolysis by the Fo×F1 complex are different (Vinogradov, A. D. (2000) J. Exp. Biol., 203, 41-49). In this paper, the author proposes a new model considering the existence in coupling membranes of two non-equilibrium isoforms of Fo×F1 unidirectionally catalyzing synthesis and/or hydrolysis of ATP.


Subject(s)
Adenosine Triphosphate/metabolism , Proton-Translocating ATPases/metabolism , Biocatalysis , Chloroplasts/enzymology , Hydrolysis , Kinetics , Mitochondria/enzymology , Paracoccus denitrificans/enzymology , Proton-Motive Force
10.
Ter Arkh ; 91(5): 89-95, 2019 May 15.
Article in Russian | MEDLINE | ID: mdl-32598682

ABSTRACT

AIM: To study the influence of the state of endothelium on the daily profile of arterial pressure (AP) in patients with rheumatoid arthritis (RA). MATERIALS AND METHODS: In 70 RA pts carried out C-reactive protein (CRP), vascular endothelial adhesion molecule type 1 (sVCAM-1), antigen von Willebrand Factor (AG WF), interleukin-8 (Il-8), rheumatoid factor (RF), IgG, endotheline-1 (ET-1), number of desquamated endotheliocytes cells (DE), VS, activity of renin by immunoenzyme analysis. The dysfunction of endothelium was evaluated by calculation of DE. The functional methods included the daily monitoring of arterial pressure (AP). RESULTS: Arterial hypertension (AH) occurred in 40 (57.1%) pts. RA pts are revealed the signs of endothelial dysfunction, about which significant differences among the indices of activation of endothelium in comparison with control group testify. ET-1, sVCAM-1, vWF AG, Il-8, CRP content was higher in RA pts. Reliably above there was a number of DE. Reliable differences according to these indices depending of RA activity were discovered. With conducting of correlation analysis it is revealed, that markers of the activation of endothelium: sVCAM-1, vWF AG positively correlated with increasing RF IgG and indices of the immune inflammation: CRP, and DE number. In patients suffering from RA, showed signs of endothelial dysfunction. The positive correlation between endothelial damage and daily profile of AP show the relationship of these processes. CONCLUSION: Positive correlations between the damage of endothelium and disturbance of AP daily profile testify about the interrelation of these processes.


Subject(s)
Arthritis, Rheumatoid , Endothelium, Vascular , Arthritis, Rheumatoid/complications , Biomarkers , Blood Pressure , Endothelium, Vascular/pathology , Humans , Rheumatoid Factor , Vascular Cell Adhesion Molecule-1 , von Willebrand Factor
11.
Ter Arkh ; 91(6): 57-61, 2019 Jun 15.
Article in Russian | MEDLINE | ID: mdl-36471596

ABSTRACT

AIM: To determine the frequency, clinical and morphological features of a nephropathy with C1q deposits in chronic glomerulonephritis adult patients. MATERIALS AND METHODS: 296 specimens of kidneys of patients with a chronic glomerulonephritis (CGN) from 2014 for 2018 were analyzed. At the first step, specimens with C1q deposits in glomeruli revealed by immunofluorescent method were chosen. Lupus nephritis and primary membranoproliferative glomerulonephritis were exclusion criteria. At the second step, the retrospective analysis of the clinical characteristics was carried out. RESULTS AND DISCUSSION: Deposits of C1q in kidneys at 12 of 296 (4.05%) CGN were revealed, m:f ratio 2:1. Average age of the beginning of a disease was 32.1±14.7 years. At a morphological research in 8 membranous nephropathy (MN), in 2 mesangioproliferative glomerulonephritis (MesPGN), in 2 - nephrosclerosis was revealed. Among 12 patients in 5 the disease debuted a nephrotic syndrome, at the others - a proteinuria from 0.5 to 4.0 g/days with the subsequent formation of a nephrotic syndrome. In 5 of 12 patients the disease was characterized by a favor course with preserved kidney function. At 7 patients at the time of inspection decrease in function of kidneys [glomerular filtration rate (eGFR) 31 (30-34) ml/min] was noted. 5 had slow progressing of a renal failure. 2 of 12 progressed to renal failure (eGFR to 19 and 24 ml/min) within a year. CONCLUSION: Deposits of C1q in kidney were revealed in 4.05% of biopsy specimens in CGN. The most frequent morphological form was the membranous nephropathy. The clinical course was characterized by a nephrotic syndrome, more than at a half of patients - with renal dysfunction.

12.
Khirurgiia (Mosk) ; (11): 109-110, 2019.
Article in Russian | MEDLINE | ID: mdl-31714539

ABSTRACT

Femoral hernia strangulation is usually observed in middle-aged women. There are few case reports of appendix strangulation in the femoral hernia. Acute appendicitis in a strangulated femoral hernia is relatively rare (0.4% of cases). Clinical case of acute destructive appendicitis within a strangulated femoral hernia in an elderly woman is reported in the article. If there is doubt about the urgency of surgical intervention, surgeon needs to take a proactive stance and lean toward emergency surgery. Surgeon should be aware of possible strangulation-associated destructive appendicitis due to injury of the appendix.


Subject(s)
Appendicitis/surgery , Hernia, Femoral/surgery , Acute Disease , Aged , Appendicitis/complications , Female , Hernia, Femoral/complications , Humans
13.
Opt Express ; 26(7): 9050-9062, 2018 Apr 02.
Article in English | MEDLINE | ID: mdl-29715863

ABSTRACT

Surface plasmon polaritons are commonly believed to be a future basis for the next generation of optoelectronic and all-optical devices. To achieve this, it is critical that the surface plasmon polariton modes be strongly confined to the surface and have a sufficiently long propagation length and a nanosize wavelength. As of today, in the visible part of the spectrum, these conditions are not satisfied for any type of surface plasmon polaritons. In this paper, we demonstrate that in the ultraviolet range, surface plasmon polaritons propagating along a periodically nanostructured aluminum-dielectric interface have all these properties. Both the confinement length and the wavelength of the mode considered are smaller than the period of the structure, which can be as small as 10 nm. At the same time, the propagation length of new surface plasmon-polaritons can reach dozens of its wavelengths. These plasmon polaritons can be observed in materials that are uncommon in plasmonics such as aluminum. The suggested modes can be used for miniaturization of optical devices.

14.
Parasite Immunol ; 40(5): e12524, 2018 05.
Article in English | MEDLINE | ID: mdl-29542174

ABSTRACT

Cryptosporidiosis causes persistent diarrhoea in infants, immunocompromised patients and elderly persons. Long-term consequences of the disease include increased risk of malignancy, cardiomyopathy and gastrointestinal inflammation. This study aimed to investigate prolonged effects of cryptosporidiosis on innate immunity and growth in neonatal C3HA mice. The disease was challenged by Cryptosporidium parvum oocyst inoculation into 7-day-old animals. The mice whose intestine smears contained 3-5 or 6 and more oocysts per microscopic field at the day 5 after infection were considered as mildly or severely infected, correspondingly. To determine natural killer cell (NK) activity, we applied 3 H-uridine cytotoxic assay to the animals at 5-68 days after infection using K562 cells as targets. At severe infection, there was a statistically significant 1.5-2.0 fold decline of body mass, spleen mass and spleen cellularity that persisted in animals of all ages. Accordingly, NK cytotoxicity showed even more drastic drop reaching 2.7-3.0 folds that was statistically significant in all animals. At mild infection, the discovered effects were less pronounced and reached significance only in some age groups. Thus, our study provides evidence that NK cells show long-term cytotoxic activity decrease following Cryptosporidium infection in neonatal mice, particularly in severe disease.


Subject(s)
Cryptosporidiosis/immunology , Cryptosporidium parvum/immunology , Gastroenteritis/immunology , Intestinal Diseases, Parasitic/immunology , Intestines/parasitology , Killer Cells, Natural/immunology , Animals , Animals, Newborn , Cryptosporidiosis/parasitology , Cryptosporidiosis/pathology , Gastroenteritis/parasitology , Immunity, Innate/immunology , Intestinal Diseases, Parasitic/parasitology , Intestines/immunology , Mice , Mice, Inbred C3H , Oocysts/growth & development , Oocysts/immunology , Spleen/cytology , Spleen/parasitology , Spleen/pathology
15.
Vestn Oftalmol ; 134(4): 80-83, 2018.
Article in Russian | MEDLINE | ID: mdl-30166515

ABSTRACT

The article presents an analysis of literature data on the changes in structure and frequency of eye injuries among the adult population of the Russian Federation over the recent years. An estimation of various socio-economic and medical factors influencing these indicators was derived. The article also reviews current methods of treatment of eye injuries, and provides an evaluation of their effectiveness.


Subject(s)
Eye Injuries , Adult , Eye Injuries/diagnosis , Eye Injuries/therapy , Humans , Russia
16.
Mamm Genome ; 28(9-10): 455-464, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28836096

ABSTRACT

The AT-rich DNA is mostly associated with condensed chromatin, whereas the GC-rich sequence is preferably located in the dispersed chromatin. The AT-rich genes are prone to be tissue-specific (silenced in most tissues), while the GC-rich genes tend to be housekeeping (expressed in many tissues). This paper reports another important property of DNA base composition, which can affect repertoire of genes with high AT content. The GC-rich sequence is more liable to mutation. We found that Spearman correlation between human gene GC content and mutation probability is above 0.9. The change of base composition even in synonymous sites affects mutation probability of nonsynonymous sites and thus of encoded proteins. There is a unique type of housekeeping genes, which are especially unsafe when prone to mutation. Natural selection which usually removes deleterious mutations, in the case of these genes only increases the hazard because it can descend to suborganismal (cellular) level. These are cell cycle-related genes. In accordance with the proposed concept, they have low GC content of synonymous sites (despite them being housekeeping). The gene-centred protein interaction enrichment analysis (PIEA) showed the core clusters of genes whose interactants are modularly enriched in genes with AT-rich synonymous codons. This interconnected network is involved in double-strand break repair, DNA integrity checkpoints and chromosome pairing at mitosis. The damage of these genes results in genome and chromosome instability leading to cancer and other 'error catastrophes'. Reducing the nonsynonymous mutations, the usage of AT-rich synonymous codons can decrease probability of cancer by above 20-fold.


Subject(s)
AT Rich Sequence/genetics , Base Composition/genetics , DNA/chemistry , DNA/genetics , Evolution, Molecular , Mutation/genetics , Animals , Cell Cycle/genetics , Codon , DNA/physiology , Databases, Genetic , GC Rich Sequence/genetics , Genome, Human/genetics , Genome, Human/physiology , Humans , Models, Genetic , Proteins/genetics , Proteins/physiology , Selection, Genetic/genetics
17.
Opt Express ; 25(3): 2790-2804, 2017 Feb 06.
Article in English | MEDLINE | ID: mdl-29518996

ABSTRACT

In 1954, Dicke predicted that a system of quantum emitters confined to a subwavelength volume would produce a superradiant burst. For such a burst to occur, the emitters must be in the special Dicke state with zero dipole moment. We show that a superradiant burst may also arise for non-Dicke initial states with a nonzero dipole moment. Both for Dicke and non-Dicke initial states, superradiance arises due to a decrease in the dispersion of the quantum phase of the emitter state. For non-Dicke states, the quantum phase is related to the phase of long-period envelopes which modulate the oscillations of the dipole moments. A decrease in the dispersion of the quantum phase causes a decrease in the dispersion of envelope phases that results in constructive interference of the envelopes and the superradiant burst.

18.
Opt Lett ; 42(21): 4303-4306, 2017 Nov 01.
Article in English | MEDLINE | ID: mdl-29088149

ABSTRACT

We show that a two-level atom with a high transition frequency ωSO can be inverted via non-radiative interaction with a cluster of excited low-frequency two-level atoms or quantum oscillators whose transition frequencies are smaller than ωSO. This phenomenon occurs due to the Förster resonant energy transfer arising during a train of quantum superoscillation of low-frequency two-level atoms. The suggested model could explain the mechanism of biophoton emission.

19.
Chem Soc Rev ; 45(19): 5408-5431, 2016 Sep 26.
Article in English | MEDLINE | ID: mdl-27711673

ABSTRACT

The last five years have witnessed a huge breakthrough in the creation and the study of the properties of a new class of compounds - metamaterials. The next stage of this technological revolution will be the development of active, controllable, and non-linear metamaterials, surpassing natural media as platforms for optical data processing and quantum information applications. However, scientists are constantly faced with the need to find new methods that can ensure the formation of quantum and non-linear metamaterials with higher resolution. One such method of producing metamaterials in the future, which will provide scalability and availability, is chemical synthesis. Meanwhile, the chemical synthesis of organized 3D structures with a period of a few nanometers and a size of up to a few millimeters is not an easy task and is yet to be resolved. The most promising avenue seems to be the use of highly porous structures based on metal-organic frameworks that have demonstrated their unique properties in the field of non-linear optics (NLO) over the past three years. Thus, the aim of this review is to examine current progress and the possibilities of using metal-organic frameworks in the field of non-linear optics as chemically obtained metamaterials of the future. The review begins by presenting the theoretical principles of physical phenomena represented by mathematical descriptions for clarity. Major attention is paid to the second harmonic generation (SHG) effect. In this section we compare inorganic single crystals, which are most commonly used to study the effect in question, to organic materials, which also possess the required properties. Based on these data, we present a rationale for the possibility of studying the non-linear optical properties of metal-organic structures as well as describing the use of synthetic approaches and the difficulties associated with them. The second part of the review explicitly acquaints the reader with a new class of materials which successfully combines the positive properties of organic and inorganic materials. Using recently synthesized metal-organic frameworks and coordination polymers in the field of non-linear optics as an example, we consider synthetic approaches used for obtaining materials with desired properties and the factors to be considered in this case. Finally, probable trends towards improving the quality of the synthesized materials with regards to their further use in the field of non-linear optical effects are described.

20.
Opt Express ; 24(4): 3464-78, 2016 Feb 22.
Article in English | MEDLINE | ID: mdl-26907005

ABSTRACT

We suggest a mechanism by which a superradiant burst emerges from a subwavelength array of nonlinear classical emitters that are not initially synchronized. The emitters interact via the field of their common radiative response. We show that only if the distribution of initial phases is not uniform does a non-zero field of radiative response arise, leading to a superradiant burst. Although this field cannot synchronize the emitters, it engenders long period envelopes for their fast oscillations. Constructive interference in the envelopes of several emitters creates a large fluctuation in dipole moments that results in a superradiant pulse. The intensity of this pulse is proportional to the square of the number of emitters participating in the fluctuation.

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