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1.
Phys Rev Lett ; 124(24): 244801, 2020 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-32639812

RESUMEN

Continuous-wave photoinjectors operating at high accelerating gradients promise to revolutionize many areas of science and applications. They can establish the basis for a new generation of monochromatic x-ray free electron lasers, high-brightness hadron beams, or a new generation of microchip production. In this Letter we report on the record-performing superconducting rf electron gun with CsK_{2}Sb photocathode. The gun is generating high charge electron bunches (up to 10 nC/bunch) and low transverse emittances, while operating for months with a single photocathode. This achievement opens a new era in generating high-power beams with a very high average brightness.

2.
Phys Rev Lett ; 124(8): 084801, 2020 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-32167359

RESUMEN

Cooling of beams of gold ions using electron bunches accelerated with radio-frequency systems was recently experimentally demonstrated in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. Such an approach is new and opens the possibility of using this technique at higher energies than possible with electrostatic acceleration of electron beams. The challenges of this approach include generation of electron beams suitable for cooling, delivery of electron bunches of the required quality to the cooling sections without degradation of beam angular divergence and energy spread, achieving the required small angles between electron and ion trajectories in the cooling sections, precise velocity matching between the two beams, high-current operation of the electron accelerator, as well as several physics effects related to bunched-beam cooling. Here we report on the first demonstration of cooling hadron beams using this new approach.

3.
Bull Exp Biol Med ; 159(5): 638-41, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26468023

RESUMEN

Gastroprotective effect of Cichorium intybus L. root extract is demonstrated on H. Shay's model of experimental ulcer in rats. The effect is attributed to the antisecretory activity of the plant and stimulation of defense barrier function of the gastric mucosa. The regulatory effect of the phytocomplex on seasonal characteristics of the gastric secretory and defense functions in dogs with Basov's fistula is detected.


Asunto(s)
Antiulcerosos/farmacología , Cichorium intybus/química , Mucosa Gástrica/efectos de los fármacos , Fitoterapia , Extractos Vegetales/farmacología , Úlcera Gástrica/tratamiento farmacológico , Animales , Antiulcerosos/aislamiento & purificación , Carbacol/farmacología , Perros , Famotidina/farmacología , Femenino , Fístula Gástrica , Jugo Gástrico/química , Jugo Gástrico/efectos de los fármacos , Jugo Gástrico/metabolismo , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patología , Masculino , Extractos Vegetales/aislamiento & purificación , Raíces de Plantas/química , Ratas , Ratas Sprague-Dawley , Estaciones del Año , Estómago/efectos de los fármacos , Estómago/patología , Úlcera Gástrica/patología
4.
Sci Rep ; 14(1): 13252, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38858396

RESUMEN

The paper presents the first experimental observation of an atypical phenomena during self-organization of dust particles into a one-dimensional chain structure levitated vertically in the plasma of a DC glow discharge. Using a laser, the third (middle) dust particle was removed from the chain of five particles so that the positions of the remaining particles did not significantly change, and a vacancy occurred in the place of the removed particle. This state of the chain turned out to be very stable, which is confirmed by the observation of the subsequent exchange of places of the fourth and the fifth particles of the chain upon the action of the laser on the forth particle. After the exchange process, vertical positions of all particles (first, second, fourth and fifth) in the chain remained almost the same as before the exchange, and the vacancy at the position of the third particle was preserved. The experimental data and the video record of the observed phenomena as well as the estimates of the plasma parameters are presented. An assumption has been made about the mechanism of the discovered phenomena that at present discharge conditions both the vacancy formation and the dust particles positions exchange are possible due to a strong ion wakes which are formed behind the upstream dust particles of the chain.

5.
Nat Commun ; 15(1): 4037, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38740793

RESUMEN

Laser-driven plasma accelerators provide tabletop sources of relativistic electron bunches and femtosecond x-ray pulses, but usually require petawatt-class solid-state-laser pulses of wavelength λL ~ 1 µm. Longer-λL lasers can potentially accelerate higher-quality bunches, since they require less power to drive larger wakes in less dense plasma. Here, we report on a self-injecting plasma accelerator driven by a long-wave-infrared laser: a chirped-pulse-amplified CO2 laser (λL ≈ 10 µm). Through optical scattering experiments, we observed wakes that 4-ps CO2 pulses with < 1/2 terawatt (TW) peak power drove in hydrogen plasma of electron density down to 4 × 1017 cm-3 (1/100 atmospheric density) via a self-modulation (SM) instability. Shorter, more powerful CO2 pulses drove wakes in plasma down to 3 × 1016 cm-3 that captured and accelerated plasma electrons to relativistic energy. Collimated quasi-monoenergetic features in the electron output marked the onset of a transition from SM to bubble-regime acceleration, portending future higher-quality accelerators driven by yet shorter, more powerful pulses.

6.
Phys Rev Lett ; 109(16): 164802, 2012 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-23215085

RESUMEN

We describe the first direct observation of the significant suppression of the energy spread induced by coherent synchrotron radiation by a pair of conductive plates placed inside a dipole magnet. In addition to various feedback loops improving the energy stability of the beam parameters, our key innovation for this experiment is the observation of the time-resolved energy variation within the electron bunch, instead of the traditionally measured rms energy spread. We present the results of the experiments and compare them with a rigorous analytical theory.

7.
Sci Rep ; 11(1): 4477, 2021 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-33627743

RESUMEN

High brightness, high charge electron beams are critical for a number of advanced accelerator applications. The initial emittance of the electron beam, which is determined by the mean transverse energy (MTE) and laser spot size, is one of the most important parameters determining the beam quality. The bialkali photocathodes illuminated by a visible laser have the advantages of high quantum efficiency (QE) and low MTE. Furthermore, Superconducting Radio Frequency (SRF) guns can operate in the continuous wave (CW) mode at high accelerating gradients, e.g. with significant reduction of the laser spot size at the photocathode. Combining the bialkali photocathode with the SRF gun enables generation of high charge, high brightness, and possibly high average current electron beams. However, integrating the high QE semiconductor photocathode into the SRF guns has been challenging. In this article, we report on the development of bialkali photocathodes for successful operation in the SRF gun with months-long lifetime while delivering CW beams with nano-coulomb charge per bunch. This achievement opens a new era for high charge, high brightness CW electron beams.

8.
Klin Med (Mosk) ; 87(2): 21-4, 2009.
Artículo en Ruso | MEDLINE | ID: mdl-19348295

RESUMEN

The aim of the study was to obtain an insight into the origin and specific features of myocardial infarction (MI) in 322 subjects below 60 yr of age. Most patients had anginous complaints. The incidence of non-anginous forms of MI in patients aged below 45 and 46-60 years was estimated with reference to the occurrence of complications. The structure of these complications and causes of their fatal outcome were elucidated. The prevalence of risk factors of MI in the survivors and patients who died was obtained.


Asunto(s)
Dolor en el Pecho/diagnóstico , Infarto del Miocardio/diagnóstico , Factores de Edad , Dolor en el Pecho/epidemiología , Dolor en el Pecho/etiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Morbilidad , Infarto del Miocardio/complicaciones , Infarto del Miocardio/epidemiología , Pronóstico , Factores de Riesgo , Federación de Rusia/epidemiología , Índice de Severidad de la Enfermedad , Tasa de Supervivencia
9.
Phys Rev E Stat Nonlin Soft Matter Phys ; 73(6 Pt 2): 066503, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16906990

RESUMEN

High-energy electron cooling, presently considered as an essential tool for several applications in high-energy and nuclear physics, requires an accurate description of the friction force which ions experience by passing through an electron beam. Present low-energy electron coolers can be used for a detailed study of the friction force. In addition, parameters of a low-energy cooler can be chosen in a manner to reproduce regimes expected in future high-energy operation. Here, we report a set of dedicated experiments in CELSIUS aimed at a detailed study of the magnetized friction force. Some results of the accurate comparison of experimental data with the friction force formulas are presented.

10.
Med Phys ; 24(3): 417-23, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9089593

RESUMEN

Radiotherapy utilizes photons for treating cancer. Historically these photons have been produced by the bremsstrahlung process. In this paper we introduce Compton backscattering as an alternate method of photon production for cancer treatment. Compton backscattering is a well-established method to produce high-energy photons (gamma rays) for nuclear physics experiments. Compton backscattering involves the collision of a low-energy (eV) photon with a high-energy (hundreds of MeV) electron. It is shown that the photons scattered in the direction opposite to the direction of the initial photon (backscattered) will have the energy desired for photon beam therapy. The output of Compton backscattering is a high-energy photon beam (gamma-ray beam), which is well collimated and has minimal low-energy components. Such gamma beams may be used for conventional high-energy photon treatments, production of radionuclides, and generation of positrons and neutrons. The theoretical basis for this process is reviewed and Monte Carlo calculations of dose profiles for peak energies of 7, 15, and 30 MeV are presented. The potential advantages of the Compton process and its future role in radiotherapy will be discussed.


Asunto(s)
Fotones/uso terapéutico , Radioterapia de Alta Energía/métodos , Dispersión de Radiación , Fenómenos Biofísicos , Biofisica , Estudios de Evaluación como Asunto , Humanos , Método de Montecarlo , Planificación de la Radioterapia Asistida por Computador , Tecnología Radiológica
11.
Artículo en Ruso | MEDLINE | ID: mdl-2515700

RESUMEN

The peculiarities of rehabilitation were studied in patients with long-lasting mental diseases who had lost their housing and relatives confined to specialized clinic-hotel or "halfway"-type units. The efficiency of these types of secure housing providing high level of therapeutic environment is stressed. The housing conditions and interrelations between the described forms are discussed.


Asunto(s)
Centros Comunitarios de Salud Mental/organización & administración , Servicios Comunitarios de Salud Mental/organización & administración , Casas de Convalecencia/organización & administración , Cuidados a Largo Plazo/organización & administración , Trastornos Mentales/rehabilitación , Humanos , Trastornos Mentales/terapia , Ucrania
12.
Artículo en Ruso | MEDLINE | ID: mdl-6711217

RESUMEN

In order to treat patients who are resistant to antialcohol therapy (110 patients), the authors used sensibilizing therapy throughout the entire course of treatment in conjunction with reflex therapy conducted by using conditional drops (1/20 part of a gulp) of alcohol. This method is technically simple, causes no complications and produces more persistent remissions, e.g. remissions lasting over one year were observed in almost half of the patients (47,2%).


Asunto(s)
Alcoholismo/terapia , Condicionamiento Clásico , Disulfiram/uso terapéutico , Adulto , Terapia Combinada , Humanos , Masculino , Persona de Mediana Edad
13.
Eksp Klin Farmakol ; 59(5): 36-9, 1996.
Artículo en Ruso | MEDLINE | ID: mdl-9026208

RESUMEN

The possibility of stimulating hemopoiesis inhibited by a single dose (2.0 Gr) of total irradiation with Lysini Baicalinatum, a vegetable origin drug, has been studied on CBA mice. A 3-fold drug administration (total dose 150 mg/kg) on days 3, 4, and 5 after irradiation promoted bone marrow erythropoiesis and less granulopoiesis. A mechanism of Lysini Baicalinatum stimulating effect is connected with intensification of hemopoiesis inducing microenvironment's functional activity.


Asunto(s)
Hematopoyesis/efectos de los fármacos , Lisina/análogos & derivados , Extractos Vegetales/farmacología , Animales , Médula Ósea/efectos de los fármacos , Médula Ósea/efectos de la radiación , Ensayo de Unidades Formadoras de Colonias , Hematopoyesis/efectos de la radiación , Lisina/farmacología , Masculino , Ratones , Ratones Endogámicos CBA , Estimulación Química , Factores de Tiempo , Irradiación Corporal Total
14.
Eksp Klin Farmakol ; 65(1): 7-10, 2002.
Artículo en Ruso | MEDLINE | ID: mdl-12025793

RESUMEN

The influence of new nootrope and adaptogen preparations representing dry extracts from Scutellaria baicalensis (Georgi), Bergenia crassifolia (Fritsch), and velvet antlers of Siberian deer (Cervus elaphus sibiricus) on the bioelectric activity (cortex Fourier spectral EEG power) under conflict situation and conditioned reflex development was studied in rats. In both tests, the drugs produced similar changes in the EEG activity: (i) increase in the partial contribution of delta-activity and general spectral power, (ii) depression in the alpha and beta 1-rhythm power, (iii) depression of theta-activity in some cases. The EEG activity changes depended on the initial state and were closely connected with the behavior of the test animals. The drug administration led to normalization of the alpha and beta 1 activity correlated with the improved behavioral characteristics. At the same time, the delta activity was virtually not affected and lost the correlation with behavior.


Asunto(s)
Corteza Cerebral/efectos de los fármacos , Electroencefalografía , Nootrópicos/farmacología , Preparaciones de Plantas/farmacología , Extractos de Tejidos/farmacología , Animales , Corteza Cerebral/fisiología , Condicionamiento Clásico/efectos de los fármacos , Conflicto Psicológico , Ciervos , Conducta de Ingestión de Líquido/efectos de los fármacos , Lamiaceae/química , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Ratas
15.
Eksp Klin Farmakol ; 60(6): 28-30, 1997.
Artículo en Ruso | MEDLINE | ID: mdl-9460593

RESUMEN

Hemopoiesis was studied in 88 patients with lung cancer during antitumor chemotherapy and its combination with a dry SB extract. Administration of the plant preparation was accompanied with hemopoiesis stimulation, intensification of bone-marrow erythro- and granulocytopoiesis and increase in the content of circulating precursors of the type of erythroid and granulomonocytic colony-forming units.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Células Pequeñas/tratamiento farmacológico , Hematopoyesis/efectos de los fármacos , Neoplasias Pulmonares/tratamiento farmacológico , Plantas Medicinales , Adenocarcinoma/sangre , Adenocarcinoma/tratamiento farmacológico , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/sangre , Carcinoma de Células Pequeñas/sangre , Carcinoma de Células Escamosas/sangre , Carcinoma de Células Escamosas/tratamiento farmacológico , Ensayo de Unidades Formadoras de Colonias , Ciclofosfamida/administración & dosificación , Ciclofosfamida/efectos adversos , Doxorrubicina/administración & dosificación , Doxorrubicina/efectos adversos , Humanos , Neoplasias Pulmonares/sangre , Masculino , Metotrexato/administración & dosificación , Metotrexato/efectos adversos , Persona de Mediana Edad , Extractos Vegetales/uso terapéutico
16.
Eksp Klin Farmakol ; 60(6): 49-51, 1997.
Artículo en Ruso | MEDLINE | ID: mdl-9460600

RESUMEN

Cytostatic therapy of patients with lung cancer is attended with decrease in the relative number of T-lymphocytes and their theophylline-resistant population. Patients who were given SB showed a tendency towards increase of these parameters during antitumor chemotherapy. The immunoregulation index (IRI) in this case was approximately twice the background values during the whole period of investigation. The inclusion of SB in the therapeutic complex promotes increase in the number of immunoglobulins A at a stable level of immunoglobulins G.


Asunto(s)
Adyuvantes Inmunológicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias Pulmonares/tratamiento farmacológico , Plantas Medicinales , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Linfocitos B/efectos de los fármacos , Linfocitos B/inmunología , Ciclofosfamida/administración & dosificación , Ciclofosfamida/efectos adversos , Doxorrubicina/administración & dosificación , Doxorrubicina/efectos adversos , Endotoxinas , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/patología , Masculino , Metotrexato/administración & dosificación , Metotrexato/efectos adversos , Persona de Mediana Edad , Estadificación de Neoplasias , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología
17.
Eksp Klin Farmakol ; 58(1): 3-7, 1995.
Artículo en Ruso | MEDLINE | ID: mdl-7787691

RESUMEN

The paper outlines the principles in designing hemostimulators by using glycosamineglycans. Hemostimulating properties of the tested agents is likely to be primarily due to the presence of D-glucuronic acid in their structure. The homotypic mechanisms are largely responsible for all agents' effect in stimulating hemopoiesis. Thus, they all virtually activate the function of the hemopoiesis-inducing microenvironment. In addition, they directly or indirectly stimulate the processes of proliferation and differentiation of precursor cells of erythro- and granulomonocytopoiesis.


Asunto(s)
Diseño de Fármacos , Glicosaminoglicanos/farmacología , Hematopoyesis/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Médula Ósea/efectos de los fármacos , Humanos , Estimulación Química , Relación Estructura-Actividad
18.
Ter Arkh ; 68(2): 34-7, 1996.
Artículo en Ruso | MEDLINE | ID: mdl-8771654

RESUMEN

Selective coronarography, assessment of hemodynamics, sinus node function, sinoatrial and intraatrial conduction were performed in 53 coronary heart disease (CHD) patients with supraventricular arrhythmia. The severity of cardiac rhythm paroxysms was evaluated at transesophageal pacing by measurements of arrhythmia induction frequency threshold. 29 patients underwent aortocoronary shunting. No relationships were found between the pattern of arrhythmia, degree of stenosis, number of coronary lesions. Aortocoronary bypass changed neither pattern nor severity of supraventricular arrhythmia.


Asunto(s)
Puente de Arteria Coronaria , Isquemia Miocárdica/fisiopatología , Nodo Sinoatrial/fisiopatología , Taquicardia Supraventricular/fisiopatología , Adulto , Femenino , Atrios Cardíacos/fisiopatología , Hemodinámica , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/complicaciones , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/cirugía , Taquicardia Supraventricular/diagnóstico , Taquicardia Supraventricular/etiología
20.
Klin Khir ; (7): 8-10, 2002 Jul.
Artículo en Ruso | MEDLINE | ID: mdl-12378926

RESUMEN

There was performed the retrospective analysis of 23 consecutive patients, to whom beside the ascending aorta aneurysm correction the aorta arch prosthesis was done in conditions of deep hypothermia, the blood circulation arrest with retrograde cerebral perfusion via vena cava superior. For an acute layering and aneurysm of aorta with pericardium tamponade or hemothorax occurrence 16 (69.6%) of patients were operated on in emergency. Hospital mortality had constituted 21.7%, including after an urgent operation performance--25% and elective surgery--14.3%.


Asunto(s)
Aorta Torácica/cirugía , Aneurisma de la Aorta/cirugía , Complicaciones Posoperatorias/mortalidad , Adulto , Anciano , Femenino , Humanos , Hipotermia Inducida , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
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