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1.
Braz. j. biol ; 83: 1-11, 2023. tab, ilus, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1469009

RESUMEN

The experimental research was carried out on the juvenile carp (Cyprinus carpio L.). The impact from supplemental feeds consisting of variable concentrations of chelate compounds, biogenic trace elements and probiotic lactobacillus-based product Bacillus subtilis VKPM B-2335 was evaluated. Optical and qualitative parameters of the lactobacillus base were studied in order to identify the major group of substances potentially able to influence the end result. The purpose of this research was to identify changes in the structure of the zymogen granules and their dimensions at which supplemental feeds produce a stimulating effect on the synthesis of zymogens in exogenous cells of the secretory part of pancreas. At the outcome of the study, for the first time, it was possible to prove that the integrated action of chelates and lactobacillus-based probiotics complemented each other. Metal chelate compounds contributed to enlargement of the zymogen granules, if compared to the control values. The bacterial products accelerated production of the zymogen granules in acinar cells diffusely located in carp hepatopancreas.


A pesquisa experimental foi realizada em carpas juvenis (Cyprinus carpio L.). O impacto de suplementos alimentares consistindo em concentrações variáveis de compostos quelatos, oligoelementos biogênicos e produto probiótico baseado em lactobacilos Bacillus subtilis VKPM B-2335 foi avaliado. Parâmetros ópticos e qualitativos da base de lactobacilos foram estudados a fim de identificar o maior grupo de substâncias potencialmente capazes de influenciar o resultado final. O objetivo dessa pesquisa foi identificar mudanças na estrutura dos grânulos de zimogênio e suas dimensões nas quais alimentos suplementares produzem um efeito estimulante na síntese de zimogênios em células exógenas da parte secretora do pâncreas. No resultado do estudo, pela primeira vez, foi possível comprovar que a ação integrada dos quelatos e dos probióticos à base de lactobacilos se complementava. Compostos quelatos metálicos contribuíram para o aumento dos grânulos de zimogênio, se comparados aos valores de controle. Os produtos bacterianos aceleraram a produção dos grânulos de zimogênio nas células acinares localizadas difusamente no hepatopâncreas da carpa.


Asunto(s)
Animales , Carpas/metabolismo , Precursores Enzimáticos , Probióticos/efectos adversos , Páncreas , Vesículas Secretoras
2.
Braz. j. biol ; 832023.
Artículo en Inglés | LILACS-Express | LILACS, VETINDEX | ID: biblio-1469228

RESUMEN

Abstract The experimental research was carried out on the juvenile carp (Cyprinus carpio L.). The impact from supplemental feeds consisting of variable concentrations of chelate compounds, biogenic trace elements and probiotic lactobacillus-based product Bacillus subtilis VKPM B-2335 was evaluated. Optical and qualitative parameters of the lactobacillus base were studied in order to identify the major group of substances potentially able to influence the end result. The purpose of this research was to identify changes in the structure of the zymogen granules and their dimensions at which supplemental feeds produce a stimulating effect on the synthesis of zymogens in exogenous cells of the secretory part of pancreas. At the outcome of the study, for the first time, it was possible to prove that the integrated action of chelates and lactobacillus-based probiotics complemented each other. Metal chelate compounds contributed to enlargement of the zymogen granules, if compared to the control values. The bacterial products accelerated production of the zymogen granules in acinar cells diffusely located in carp hepatopancreas.


Resumo A pesquisa experimental foi realizada em carpas juvenis (Cyprinus carpio L.). O impacto de suplementos alimentares consistindo em concentrações variáveis de compostos quelatos, oligoelementos biogênicos e produto probiótico baseado em lactobacilos Bacillus subtilis VKPM B-2335 foi avaliado. Parâmetros ópticos e qualitativos da base de lactobacilos foram estudados a fim de identificar o maior grupo de substâncias potencialmente capazes de influenciar o resultado final. O objetivo dessa pesquisa foi identificar mudanças na estrutura dos grânulos de zimogênio e suas dimensões nas quais alimentos suplementares produzem um efeito estimulante na síntese de zimogênios em células exógenas da parte secretora do pâncreas. No resultado do estudo, pela primeira vez, foi possível comprovar que a ação integrada dos quelatos e dos probióticos à base de lactobacilos se complementava. Compostos quelatos metálicos contribuíram para o aumento dos grânulos de zimogênio, se comparados aos valores de controle. Os produtos bacterianos aceleraram a produção dos grânulos de zimogênio nas células acinares localizadas difusamente no hepatopâncreas da carpa.

3.
Phys Rev Lett ; 129(9): 094801, 2022 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-36083652

RESUMEN

Laser-plasma accelerators outperform current radio frequency technology in acceleration strength by orders of magnitude. Yet, enabling them to deliver competitive beam quality for demanding applications, particularly in terms of energy spread and stability, remains a major challenge. In this Letter, we propose to combine bunch decompression and active plasma dechirping for drastically improving the energy profile and stability of beams from laser-plasma accelerators. Realistic start-to-end simulations demonstrate the potential of these postacceleration phase-space manipulations for simultaneously reducing an initial energy spread and energy jitter of ∼1-2% to ≲0.1%, closing the beam-quality gap to conventional acceleration schemes.

4.
Braz J Biol ; 83: e250219, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34909836

RESUMEN

The experimental research was carried out on the juvenile carp (Cyprinus carpio L.). The impact from supplemental feeds consisting of variable concentrations of chelate compounds, biogenic trace elements and probiotic lactobacillus-based product Bacillus subtilis VKPM B-2335 was evaluated. Optical and qualitative parameters of the lactobacillus base were studied in order to identify the major group of substances potentially able to influence the end result. The purpose of this research was to identify changes in the structure of the zymogen granules and their dimensions at which supplemental feeds produce a stimulating effect on the synthesis of zymogens in exogenous cells of the secretory part of pancreas. At the outcome of the study, for the first time, it was possible to prove that the integrated action of chelates and lactobacillus-based probiotics complemented each other. Metal chelate compounds contributed to enlargement of the zymogen granules, if compared to the control values. The bacterial products accelerated production of the zymogen granules in acinar cells diffusely located in carp hepatopancreas.


Asunto(s)
Carpas , Probióticos , Alimentación Animal/análisis , Animales , Lactobacillus , Alimentos Marinos
5.
Phys Rev Lett ; 126(16): 164801, 2021 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-33961460

RESUMEN

Landau damping is an essential mechanism for ensuring collective beam stability in particle accelerators. Precise knowledge of the strength of Landau damping is key to making accurate predictions on beam stability for state-of-the-art high-energy colliders. In this Letter, we demonstrate an experimental procedure that would allow quantifying the strength of Landau damping and the limits of beam stability using an active transverse feedback as a controllable source of beam coupling impedance. In a proof-of-principle test performed at the Large Hadron Collider, stability diagrams for a range of Landau octupole strengths have been measured. In the future, the procedure could become an accurate way of measuring stability diagrams throughout the machine cycle.

6.
Phys Rev Lett ; 120(11): 114801, 2018 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-29601751

RESUMEN

Collinear wakefield acceleration has been long established as a method capable of generating ultrahigh acceleration gradients. Because of the success on this front, recently, more efforts have shifted towards developing methods to raise the transformer ratio (TR). This figure of merit is defined as the ratio of the peak acceleration field behind the drive bunch to the peak deceleration field inside the drive bunch. TR is always less than 2 for temporally symmetric drive bunch distributions and therefore recent efforts have focused on generating asymmetric distributions to overcome this limitation. In this Letter, we report on using the emittance-exchange method to generate a shaped drive bunch to experimentally demonstrate a TR≈5 in a dielectric wakefield accelerator.

7.
PLoS One ; 12(8): e0182800, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28800583

RESUMEN

Dps is a multifunctional homododecameric protein that oxidizes Fe2+ ions accumulating them in the form of Fe2O3 within its protein cavity, interacts with DNA tightly condensing bacterial nucleoid upon starvation and performs some other functions. During the last two decades from discovery of this protein, its ferroxidase activity became rather well studied, but the mechanism of Dps interaction with DNA still remains enigmatic. The crucial role of lysine residues in the unstructured N-terminal tails led to the conventional point of view that Dps binds DNA without sequence or structural specificity. However, deletion of dps changed the profile of proteins in starved cells, SELEX screen revealed genomic regions preferentially bound in vitro and certain affinity of Dps for artificial branched molecules was detected by atomic force microscopy. Here we report a non-random distribution of Dps binding sites across the bacterial chromosome in exponentially growing cells and show their enrichment with inverted repeats prone to form secondary structures. We found that the Dps-bound regions overlap with sites occupied by other nucleoid proteins, and contain overrepresented motifs typical for their consensus sequences. Of the two types of genomic domains with extensive protein occupancy, which can be highly expressed or transcriptionally silent only those that are enriched with RNA polymerase molecules were preferentially occupied by Dps. In the dps-null mutant we, therefore, observed a differentially altered expression of several targeted genes and found suppressed transcription from the dps promoter. In most cases this can be explained by the relieved interference with Dps for nucleoid proteins exploiting sequence-specific modes of DNA binding. Thus, protecting bacterial cells from different stresses during exponential growth, Dps can modulate transcriptional integrity of the bacterial chromosome hampering RNA biosynthesis from some genes via competition with RNA polymerase or, vice versa, competing with inhibitors to activate transcription.


Asunto(s)
Proteínas Bacterianas/genética , Cromosomas Bacterianos/química , ADN Bacteriano/genética , Proteínas de Unión al ADN/genética , Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica , Proteínas Bacterianas/metabolismo , Sitios de Unión , Unión Competitiva , Mapeo Cromosómico , ADN Bacteriano/metabolismo , Proteínas de Unión al ADN/metabolismo , ARN Polimerasas Dirigidas por ADN/genética , ARN Polimerasas Dirigidas por ADN/metabolismo , Escherichia coli/metabolismo , Secuencias Invertidas Repetidas , Mutación , Regiones Promotoras Genéticas , Unión Proteica
8.
J Synchrotron Radiat ; 23(Pt 3): 850, 2016 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-27140168

RESUMEN

A correction is made to a citation in the article by Antipov et al. (2016) [J. Synchrotron Rad. 23, 163-168].

9.
Phys Rev Lett ; 116(5): 054801, 2016 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-26894715

RESUMEN

Electron beam interaction with high frequency structures (beyond microwave regime) has a great impact on future high energy frontier machines. We report on the generation of multimegawatt pulsed rf power at 91 GHz in a planar metallic accelerating structure driven by an ultrarelativistic electron bunch train. This slow-wave wakefield device can also be used for high gradient acceleration of electrons with a stable rf phase and amplitude which are controlled by manipulation of the bunch train. To achieve precise control of the rf pulse properties, a two-beam wakefield interferometry method was developed in which the rf pulse, due to the interference of the wakefields from the two bunches, was measured as a function of bunch separation. Measurements of the energy change of a trailing electron bunch as a function of the bunch separation confirmed the interferometry method.

10.
J Synchrotron Radiat ; 23(1): 163-8, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26698059

RESUMEN

The fabrication and performance evaluation of single-crystal diamond refractive X-ray lenses of which the surfaces are paraboloids of revolution for focusing X-rays in two dimensions simultaneously are reported. The lenses were manufactured using a femtosecond laser micromachining process and tested using X-ray synchrotron radiation. Such lenses were stacked together to form a standard compound refractive lens (CRL). Owing to the superior physical properties of the material, diamond CRLs could become indispensable wavefront-preserving primary focusing optics for X-ray free-electron lasers and the next-generation synchrotron storage rings. They can be used for highly efficient refocusing of the extremely bright X-ray sources for secondary optical schemes with limited aperture such as nanofocusing Fresnel zone plates and multilayer Laue lenses.


Asunto(s)
Cristalización , Diamante , Óptica y Fotónica , Rayos X
11.
Gig Sanit ; 94(9): 47-50, 2015.
Artículo en Ruso | MEDLINE | ID: mdl-27029169

RESUMEN

Implementation of non-waste technologies at the poultry establishments supposes the involvement of by-products of slaughter of birds, in particular, the blood as a source of protein and unique organic iron. For the feasibility of reasonable approaches to the possible use of birds' blood in the production of technologically acceptable emulsions there was studied and identified by the method of PCR analysis the species composition of microflora in the process of blood collection and storage, as also the environment of the slaughterhouses, there was considered the dynamics of the growth of microorganisms and measures for its limitation.


Asunto(s)
Mataderos , Sangre/microbiología , Pollos/microbiología , Contaminación de Alimentos/análisis , Microbiología de Alimentos/métodos , Exposición Profesional/análisis , Animales , Humanos
12.
Opt Express ; 22(8): 8902-7, 2014 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-24787779

RESUMEN

We analyze radiation produced by an ultrarelativistic charge as it exits the open end of a cylindrical waveguide with a dielectric lining. The end of the waveguide can be either orthogonal to the structure axis or skewed. To obtain terahertz radiation from waveguides with centimeter or millimeter radii, we consider high order TM(0m) modes driven by the beam. We obtain an integral representation which describes the radiation produced by a single waveguide mode in the Fraunhofer zone. We perform a series of numerical calculations for structures which look promising for generation of THz radiation. It is shown that for a mode with large mode number, the aperture of the vacuum channel gives the main contribution to the field if the skew angle of the waveguide aperture is not too small. Simple expressions for the angle of the main pattern lobe maximum are obtained.

13.
Phys Rev Lett ; 112(11): 114801, 2014 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-24702378

RESUMEN

A tunable energy-chirp compensator was used to remove a correlated energy chirp from the 60-MeV beam at the Brookhaven National Laboratory Accelerator Test Facility. The compensator operates through the interaction of the wakefield of the electron bunch with itself and consists of a planar structure comprised of two alumina bars with copper-plated backs separated by an adjustable beam aperture. By changing the gap size, the correlated energy chirp of the electron bunch was completely removed. Calculations show that this device, properly scaled to account for the electron bunch charge and length, can be used to remove residual correlated energy spread at the end of the linacs used for free-electron lasers. The experimental results are shown to be in good agreement with numerical simulations. Application of this technique can significantly simplify linac design and improve free-electron lasers performance.

14.
Phys Rev Lett ; 111(13): 134802, 2013 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-24116784

RESUMEN

A strong energy modulation in an electron bunch passing through a dielectric-lined waveguide was recently demonstrated in Antipov et al., Phys. Rev. Lett. 108, 144801 (2012). In this Letter, we demonstrate a successful conversion of this energy modulation into a beam density modulation, and the formation of a series of microbunches with a subpicosecond periodicity by means of magnetic optics (chicane). A strong coherent transition radiation signal produced by the microbunches is obtained and the tunability of its carrier frequency in the 0.68-0.9 THz range by regulating the energy chirp in the incoming electron bunch is demonstrated using infrared interferometry. A tabletop, compact, tunable, and narrowband source of intense THz radiation based on this technology is proposed.

15.
Artículo en Inglés | MEDLINE | ID: mdl-23410440

RESUMEN

A self-consistent nonlocal model of the positive column of a dc glow discharge with dust particles is presented. Radial distributions of plasma parameters and the dust component in an axially homogeneous glow discharge are considered. The model is based on the solution of a nonlocal Boltzmann equation for the electron energy distribution function, drift-diffusion equations for ions, and the Poisson equation for a self-consistent electric field. The radial distribution of dust particle density in a dust cloud was fixed as a given steplike function or was chosen according to an equilibrium Boltzmann distribution. The balance of electron and ion production in argon ionization by an electron impact and their losses on the dust particle surface and on the discharge tube walls is taken into account. The interrelation of discharge plasma and the dust cloud is studied in a self-consistent way, and the radial distributions of the discharge plasma and dust particle parameters are obtained. It is shown that the influence of the dust cloud on the discharge plasma has a nonlocal behavior, e.g., density and charge distributions in the dust cloud substantially depend on the plasma parameters outside the dust cloud. As a result of a self-consistent evolution of plasma parameters to equilibrium steady-state conditions, ionization and recombination rates become equal to each other, electron and ion radial fluxes become equal to zero, and the radial component of electric field is expelled from the dust cloud.


Asunto(s)
Algoritmos , Modelos Químicos , Gases em Plasma/química , Reología/métodos , Simulación por Computador , Campos Electromagnéticos , Gases em Plasma/efectos de la radiación
16.
Kardiologiia ; 53(10): 10-5, 2013.
Artículo en Ruso | MEDLINE | ID: mdl-24645550

RESUMEN

In order to assess comparative efficacy of pharmacoinvasive strategy of myocardial reperfusion and primary angioplasty in ST elevation acute myocardial infarction 289 patients were randomized at prehospital stage within first 6 hours of the disease into 2 groups: primary angioplasty (group 1), and prehospital thrombolysis with subsequent rescue or delayed angioplasty depending on efficacy of thrombolysis. We analyzed clinical and anamnestic characteristics of patients, efficacy of reperfusion measures, dimensions of myocardial necrosis, and clinical course of the disease. Pharmacoinvasive myocardial reperfusion with prehospital thrombolysis compared with primary coronary angioplasty decreased time of myocardial ischemia (224.65 +/- 71 vs. 278 +/- 184 min, p < 0.03), increased rate of achievement of TIMI grade 3 flow after percutaneous coronary intervention (80.5% vs. 71.4%, p = 0.002) and more effectively preserved left ventricular ejection fraction (60.0 +/- 14.9% vs. 54.9 +/- 12.3%, p < 0.01). Prehospital thrombolysis before coronary angioplasty compared with primary angioplasty was associated with lower rate of development of no-reflow syndrome (1.4% vs. 11.6%, p < 0.003).


Asunto(s)
Angioplastia Coronaria con Balón/métodos , Electrocardiografía , Infarto del Miocardio/terapia , Reperfusión Miocárdica/métodos , Intervención Coronaria Percutánea/métodos , Terapia Trombolítica/métodos , Activador de Tejido Plasminógeno/uso terapéutico , Angiografía Coronaria , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/fisiopatología , Guías de Práctica Clínica como Asunto , Resultado del Tratamiento
17.
Med Tr Prom Ekol ; (5): 37-41, 2012.
Artículo en Ruso | MEDLINE | ID: mdl-22855998

RESUMEN

The state of occupational health problem and occupational rate of accident in Russia has been studied. It has been set forward the innovation model of health care of employees in oil and gas industry based on integrated approach, which combines the medical examination practice, the objective appraisal of workplaces on working condition, use of new saving production technologies, providing the employees with the means of individual protection, teaching the personnel to occupational safety and health culture and the first medical aid. The received results approve the efficiency of application of this model.


Asunto(s)
Industria Procesadora y de Extracción , Modelos Teóricos , Enfermedades Profesionales/prevención & control , Exposición Profesional/análisis , Salud Laboral , Lugar de Trabajo/normas , Humanos , Tamizaje Masivo , Enfermedades Profesionales/diagnóstico , Yacimiento de Petróleo y Gas , Federación de Rusia
18.
Phys Rev Lett ; 108(14): 144801, 2012 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-22540797

RESUMEN

We report the observation of a strong wakefield induced energy modulation in an energy-chirped electron bunch passing through a dielectric-lined waveguide. This modulation can be effectively converted into a spatial modulation forming microbunches with a periodicity of 0.5-1 ps and, hence, capable of driving coherent terahertz radiation. The experimental results agree well with theoretical predictions.

19.
Phys Rev Lett ; 106(16): 164802, 2011 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-21599371

RESUMEN

We report on a collinear wakefield experiment using the first tunable dielectric loaded accelerating structure. By introducing an extra layer of nonlinear ferroelectric, which has a dielectric constant sensitive to temperature and dc bias, the frequency of a dielectric loaded accelerating structure can be tuned. During the experiment, the energy of a witness bunch at a fixed delay with respect to the drive beam was measured while the temperature of the structure was scanned over a 50 °C range. The energy change corresponded to a change of more than half of the nominal structure wavelength.

20.
Phys Rev E Stat Nonlin Soft Matter Phys ; 79(3 Pt 2): 036404, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19392061

RESUMEN

Dust-particles charging in a low-pressure glow discharge was investigated theoretically. The dust-particle charge was found on the basis of a developed self-consistent model taking into account the nonequilibrium character of electron distribution function and the formation of an ionic coat composed of bound or trapped ions around the dust particle. The dust-particle charge, the radial distributions of electron density, free and trapped ions densities, and the distribution of electrostatic potential were found. It was shown that the non-Maxwellian electron distribution function and collisional flux of trapped ions both reduce the dust-particle charge in comparison with that received with the help of the conventional orbital motion limited (OML) model. However, in rare collisional regimes in plasma when the collisional flux is negligible, the formation of ionic coat around a particle leads to a shielding of the proper charge of a dust particle. In low-pressure experiments, it is only possible to detect the effective charge of a dust particle that is equal to the difference between the proper charge of the particle and the charge of trapped ions. The calculated effective dust particle charge is in fairly good agreement with the experimental measurements of dust-particle charge dependence on gas pressure.

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