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1.
Phys Rev Lett ; 132(8): 083402, 2024 Feb 23.
Article in English | MEDLINE | ID: mdl-38457696

ABSTRACT

We report on laser cooling of a large fraction of positronium (Ps) in free flight by strongly saturating the 1^{3}S-2^{3}P transition with a broadband, long-pulsed 243 nm alexandrite laser. The ground state Ps cloud is produced in a magnetic and electric field-free environment. We observe two different laser-induced effects. The first effect is an increase in the number of atoms in the ground state after the time Ps has spent in the long-lived 2^{3}P states. The second effect is one-dimensional Doppler cooling of Ps, reducing the cloud's temperature from 380(20) to 170(20) K. We demonstrate a 58(9)% increase in the fraction of Ps atoms with v_{1D}<3.7×10^{4} ms^{-1}.

2.
Zh Evol Biokhim Fiziol ; 31(1): 72-8, 1995.
Article in Russian | MEDLINE | ID: mdl-7571912

ABSTRACT

Learning behaviour in chimpanzee has been investigated on a group of three animals at the age of 5-6 years. Situation conditioned reflex was elaborated in unrestrained monkeys which were trained to visual discrimination between abstract images of various complexity. Changes in experimental situation significantly affected learning process. It was shown that social contacts with experimenter are important for the effective learning in juvenile chimpanzee.


Subject(s)
Discrimination Learning , Pan troglodytes/psychology , Social Behavior , Animals , Conditioning, Classical , Female , Form Perception , Male , Photic Stimulation , Reaction Time
3.
Khirurgiia (Mosk) ; (5): 56-9, 1990 May.
Article in Russian | MEDLINE | ID: mdl-2391940

ABSTRACT

The article deals with the results of studying regional microcirculation in 550 patients with chronic arterial insufficiency. Radioisotope study of blood flow in the muscles with isotopes 131I or 133Xe before and after muscular exertion, morpho-histological++ study of biopsies from a skeletal muscle, histochemical and ultrastructural study of the microcirculatory channel were carried out. Analysis of the findings made it possible to distinguish, according to the changes in circulation in the tissues, three clinical groups of patients (compensated, subcompensated, and decompensated), to determine the indications and contraindications for various types of reconstructive operations, and to prognosticate with high authenticity the outcome of the disease.


Subject(s)
Aortic Diseases/surgery , Arteriosclerosis Obliterans/surgery , Blood Vessel Prosthesis , Endarterectomy , Endarteritis/surgery , Femoral Artery/surgery , Iliac Artery/surgery , Leg/blood supply , Muscles/blood supply , Aorta, Abdominal/physiopathology , Aorta, Abdominal/surgery , Aortic Diseases/physiopathology , Arteriosclerosis Obliterans/physiopathology , Endarteritis/physiopathology , Femoral Artery/physiopathology , Humans , Iliac Artery/physiopathology , Microcirculation/physiopathology , Regional Blood Flow
5.
Biull Eksp Biol Med ; 95(3): 83-5, 1983 Mar.
Article in Russian | MEDLINE | ID: mdl-6338963

ABSTRACT

The authors studied the possibilities of long-term culture of islet cells of guinea-pig pancreas by passages. beta-cells of guinea-pig pancreas were cultured for 180 days and underwent 6 passages. Morphological and radioimmunological studies of long-term-viable cells of the pancreas have shown that regular passages enable the obtaining of a homogeneous population of beta-cells. During all the passages, the cells preserve the morphological and functional features of islet tissue.


Subject(s)
Insulin/metabolism , Islets of Langerhans/metabolism , Animals , Cells, Cultured , Guinea Pigs , Insulin Secretion , Islets of Langerhans/cytology , Time Factors , Tissue Preservation
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