Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 28
Filter
Add more filters










Publication year range
1.
Phys Rev Lett ; 130(5): 051802, 2023 Feb 03.
Article in English | MEDLINE | ID: mdl-36800478

ABSTRACT

The inclusive electron neutrino charged-current cross section is measured in the NOvA near detector using 8.02×10^{20} protons-on-target in the NuMI beam. The sample of GeV electron neutrino interactions is the largest analyzed to date and is limited by ≃17% systematic rather than the ≃7.4% statistical uncertainties. The double-differential cross section in final-state electron energy and angle is presented for the first time, together with the single-differential dependence on Q^{2} (squared four-momentum transfer) and energy, in the range 1 GeV≤E_{ν}<6 GeV. Detailed comparisons are made to the predictions of the GENIE, GiBUU, NEUT, and NuWro neutrino event generators. The data do not strongly favor a model over the others consistently across all three cross sections measured, though some models have especially good or poor agreement in the single differential cross section vs Q^{2}.

2.
Phys Rev Lett ; 127(20): 201801, 2021 Nov 12.
Article in English | MEDLINE | ID: mdl-34860065

ABSTRACT

This Letter reports results from the first long-baseline search for sterile antineutrinos mixing in an accelerator-based antineutrino-dominated beam. The rate of neutral-current interactions in the two NOvA detectors, at distances of 1 and 810 km from the beam source, is analyzed using an exposure of 12.51×10^{20} protons-on-target from the NuMI beam at Fermilab running in antineutrino mode. A total of 121 of neutral-current candidates are observed at the far detector, compared to a prediction of 122±11(stat.)±15(syst.) assuming mixing only between three active flavors. No evidence for ν[over ¯]_{µ}→ν[over ¯]_{s} oscillation is observed. Interpreting this result within a 3+1 model, constraints are placed on the mixing angles θ_{24}<25° and θ_{34}<32° at the 90% C.L. for 0.05 eV^{2}≤Δm_{41}^{2}≤0.5 eV^{2}, the range of mass splittings that produces no significant oscillations at the near detector. These are the first 3+1 confidence limits set using long-baseline accelerator antineutrinos.

3.
Phys Rev Lett ; 123(15): 151803, 2019 Oct 11.
Article in English | MEDLINE | ID: mdl-31702305

ABSTRACT

The NOvA experiment has seen a 4.4σ signal of ν[over ¯]_{e} appearance in a 2 GeV ν[over ¯]_{µ} beam at a distance of 810 km. Using 12.33×10^{20} protons on target delivered to the Fermilab NuMI neutrino beamline, the experiment recorded 27 ν[over ¯]_{µ}→ν[over ¯]_{e} candidates with a background of 10.3 and 102 ν[over ¯]_{µ}→ν[over ¯]_{µ} candidates. This new antineutrino data are combined with neutrino data to measure the parameters |Δm_{32}^{2}|=2.48_{-0.06}^{+0.11}×10^{-3} eV^{2}/c^{4} and sin^{2}θ_{23} in the ranges from (0.53-0.60) and (0.45-0.48) in the normal neutrino mass hierarchy. The data exclude most values near δ_{CP}=π/2 for the inverted mass hierarchy by more than 3σ and favor the normal neutrino mass hierarchy by 1.9σ and θ_{23} values in the upper octant by 1.6σ.

4.
Ross Fiziol Zh Im I M Sechenova ; 84(7): 663-71, 1998 Jul.
Article in Russian | MEDLINE | ID: mdl-9805778

ABSTRACT

Effects of some fragments of alpha-calcitonine gene-related peptide (alpha-CGRP) on the collector lymphatic vessels of the rat small intestine mesenterium, were studied. All the fragments excepting alpha-CGRP (21-24) and (21-31) activate motility of the lymphatic vessels enhancing phasic contractions of the walls. Presence of aminoacid residuals in the 20-29 area is "critical" for realising vasoactive properties by these fragments.


Subject(s)
Calcitonin Gene-Related Peptide/physiology , Lymphatic System/drug effects , Peptide Fragments/pharmacology , Vasoconstriction/drug effects , Animals , Calcitonin Gene-Related Peptide/chemistry , Humans , In Vitro Techniques , Intestine, Small/drug effects , Lymphatic System/physiology , Male , Mesentery/drug effects , Peptide Fragments/chemistry , Rats , Rats, Wistar
6.
Invest Ophthalmol Vis Sci ; 38(1): 167-75, 1997 Jan.
Article in English | MEDLINE | ID: mdl-9008641

ABSTRACT

PURPOSE: To investigate the biochemical mechanisms responsible for the specific uptake, concentration, and stabilization of the carotenoids lutein and zeaxanthin in the macula. METHODS: Soluble extracts of bovine retina mixed with radioactive carotenoids were purified by hydrophobic interaction, ion exchange, and gel filtration chromatography. Carotenoid-associated proteins in these purified preparations were identified through photoaffinity labeling and protein microsequencing. Similar purifications on human macular tissue without the addition of exogenous carotenoids also were performed. RESULTS: Experiments on bovine retinal tissue demonstrated that tubulin is the major soluble carotenoid-binding protein. When soluble extracts of human macular protein were examined, the endogenous carotenoids lutein and zeaxanthin were found to copurify with tubulin. CONCLUSIONS: Tubulin is found in abundance in the receptor axon layer of the fovea, where it can serve as a locus for the deposition of the high concentrations of macular carotenoids found there. The binding interaction of carotenoids and tubulin in the Henle's fiber layer could play an important role in the photoprotective effects of the macular carotenoids against the progression of age-related macular degeneration. The association of carotenoids with tubulin, a protein that can form highly ordered linear arrays, may provide an explanation for the dichroic phenomenon of Haidinger's brushes.


Subject(s)
Lutein/metabolism , Macula Lutea/metabolism , Retina/metabolism , Tubulin/metabolism , beta Carotene/analogs & derivatives , Affinity Labels , Animals , Blotting, Western , Cattle , Chromatography, Gel , Chromatography, Ion Exchange , Electrophoresis, Polyacrylamide Gel , Humans , Lutein/isolation & purification , Macula Lutea/chemistry , Protein Binding , Retina/chemistry , Tubulin/isolation & purification , Xanthophylls , Zeaxanthins , beta Carotene/isolation & purification , beta Carotene/metabolism
7.
8.
Fiziol Zh Im I M Sechenova ; 81(6): 59-65, 1995 Jun.
Article in Russian | MEDLINE | ID: mdl-8845879

ABSTRACT

Fragments of the calcitonin gene-related neuropeptide's molecule with the amino acid sequence 1-9, 10-20, 15-24, 20-29 and 30-37, were studied. The fragment 20-29 revealed the greatest biological activity: it induced a dose-dependent drop of arterial pressure in i.v. administration, enlarges arterial and venous microvessels when locally applied.


Subject(s)
Calcitonin Gene-Related Peptide/physiology , Mesentery/blood supply , Peptide Fragments/physiology , Animals , Calcitonin Gene-Related Peptide/pharmacology , Dose-Response Relationship, Drug , Lymphatic System/drug effects , Lymphatic System/physiology , Male , Mesentery/drug effects , Microcirculation/drug effects , Microcirculation/physiology , Peptide Fragments/pharmacology , Rats , Rats, Wistar , Structure-Activity Relationship
11.
Fiziol Zh SSSR Im I M Sechenova ; 77(9): 224-31, 1991 Sep.
Article in Russian | MEDLINE | ID: mdl-1666608

ABSTRACT

In rats with experimental hypertension, mesenteric artery revealed a hypersensitivity to noradrenaline whereas aorta did not differ from normal values of this parameter. The sensitivity of femoral artery was lowered. The microarterioles of hypertensive animals manifested a lower sensitivity to noradrenaline as well. This data suggests that arterial vessels manifest a regional heterogeneity of their functional properties in chronic birenal renovascular hypertension.


Subject(s)
Arteries/physiopathology , Hypertension, Renovascular/physiopathology , Animals , Aorta/drug effects , Aorta/physiopathology , Arteries/drug effects , Chronic Disease , Dose-Response Relationship, Drug , Femoral Artery/drug effects , Femoral Artery/physiopathology , Male , Mesenteric Arteries/drug effects , Mesenteric Arteries/physiopathology , Microcirculation/drug effects , Microcirculation/physiopathology , Norepinephrine/pharmacology , Rats , Rats, Inbred Strains
12.
Fiziol Zh SSSR Im I M Sechenova ; 77(6): 34-41, 1991 Jun.
Article in Russian | MEDLINE | ID: mdl-1665817

ABSTRACT

The sensitivity of smooth muscle cells' adrenoreceptors to noradrenaline (NA) and dopamine (DA) was studied in intact and desympathised arterial microvessels of the rabbit mesentery. The arterioles differed from each other in their sensitivity to catecholamines depending on their diameter. However, in conditions of chemical desympathisation, the sensitivity to NA and DA increased in all the microvessels whereas the degree of narrowing of the microvessels' lumen remained practically the same. These findings suggest a heterogeneous character of physiological properties of vascular smooth muscle cells within the arterial part of the microcirculatory module of the rabbit mesentery.


Subject(s)
Catecholamines/pharmacology , Mesentery/drug effects , Muscle, Smooth, Vascular/drug effects , Sympathetic Nervous System/drug effects , Animals , Arterioles/drug effects , Arterioles/innervation , Arterioles/physiology , Mesentery/blood supply , Mesentery/innervation , Microinjections , Muscle, Smooth, Vascular/innervation , Muscle, Smooth, Vascular/physiology , Oxidopamine , Rabbits , Sympathectomy, Chemical , Sympathetic Nervous System/physiology
13.
Zh Evol Biokhim Fiziol ; 26(1): 136-8, 1990.
Article in Russian | MEDLINE | ID: mdl-2360377

ABSTRACT

Television microscopic studies have been made of the reaction of mesenterial metarterioles to noradrenalin in newborn, 10- and 30-day rabbits. The results obtained show the existence of postnatal changes in the reactivity of arterioles with a diameter 20-25 mu. Within the period investigated, noradrenalin sensitivity of metarterioles decreases whereas their contractile activity increases. It is suggested that formation of functional properties of metarterioles is not accomplished to the birth of rabbits.


Subject(s)
Growth/physiology , Mesenteric Arteries/physiology , Aging/drug effects , Aging/physiology , Animals , Animals, Newborn , Arterioles/drug effects , Arterioles/physiology , Growth/drug effects , Male , Mesenteric Arteries/drug effects , Norepinephrine/pharmacology , Rabbits
14.
Vopr Med Khim ; 36(1): 84-7, 1990.
Article in Russian | MEDLINE | ID: mdl-2343584

ABSTRACT

Properties of the adenylate cyclase system were simultaneously studied in heart and aorta of rats with renovascular hypertension. Under conditions of the pathology molecular interactions between adrenoreceptors, regulating proteins (N-proteins) and catalytic subunit of the adenylate cyclase system were deteriorated in rat myocardium as well as functions of the regulating component were impaired in the adenylate cyclase system of aorta smooth muscles.


Subject(s)
Adenylyl Cyclases/metabolism , Aorta/enzymology , Hypertension, Renal/enzymology , Myocardium/enzymology , Adenylyl Cyclase Inhibitors , Animals , Enzyme Activation , Guanosine Triphosphate/pharmacology , Isoproterenol/pharmacology , Male , Muscle, Smooth, Vascular/enzymology , Rats , Rats, Inbred Strains , Sodium Fluoride/pharmacology
16.
Fiziol Zh SSSR Im I M Sechenova ; 75(3): 386-90, 1989 Mar.
Article in Russian | MEDLINE | ID: mdl-2547669

ABSTRACT

The renovascular hypertension in the Wistar rats was induced by clipping both renal arteries. Within 3-4 weeks arterial pressure (AP) increased to maximal values. According to AP, the rats were divided into two groups: with AP less than or equal to 170 mm Hg and greater than 170 mm Hg. In 5-6 or 10-11 weeks the animals were decapitated and the Na,K-ATPase activities in the wholesome erythrocytes, their ghosts, and the cortex and medulla of kidneys were studied. Changes of the enzyme activity were only found in the medulla. A decreased enzyme activity (-20%) was revealed in the rats with AP less than or equal to 170 mm Hg within 5-6 weeks after renal ischemia, the activity increasing again in 10-11 weeks after the operation. The decreasing of Na,K-ATPase activity within 5-6 weeks after renal ischemia could be a mechanism of adaptation of the salt-water balance in animals.


Subject(s)
Erythrocytes/enzymology , Ischemia/enzymology , Kidney/blood supply , Sodium-Potassium-Exchanging ATPase/metabolism , Animals , Kidney/enzymology , Kidney/pathology , Male , Rats , Rats, Inbred Strains , Sodium-Potassium-Exchanging ATPase/blood , Time Factors
17.
Fiziol Zh SSSR Im I M Sechenova ; 72(2): 176-82, 1986 Feb.
Article in Russian | MEDLINE | ID: mdl-3699182

ABSTRACT

In anesthetized cats, the enhancement of sympathetic activity and increase of the blood pressure in exclusion of afferents (section of vagosympathetic trunks and clamping of common carotid arteries) as well as the disappearance of the activity in enhanced afferentation, were shown to be transient and to disappear within a few minutes-scores of minutes in spite of the going on deafferentation or enhancement of afferentation. The afferent influences from the arterial baroreceptors seem to have no major significance for the long-term control of sympathetic tone.


Subject(s)
Aorta/innervation , Blood Pressure , Pressoreceptors/physiology , Vasomotor System/physiology , Animals , Autonomic Fibers, Postganglionic/physiology , Carotid Sinus/physiology , Cats , Heart Rate , Kidney/innervation , Male , Reflex/physiology , Vagus Nerve/physiology
18.
Fiziol Zh SSSR Im I M Sechenova ; 71(6): 719-23, 1985 Jun.
Article in Russian | MEDLINE | ID: mdl-4029440

ABSTRACT

After removal of the supper cervical sympathetic ganglion in cats followed by increase of the intraocular pressure from 20 to 32 mm Hg, the outflow of intraocular fluid was sharply enhanced due to lowering tone of tissues of the eye drainage apparatus in the desympathised eye. Noradrenaline was found to reduce sharply by the 4th-5th day in the desympathised eye's tissues due to degenerative processes whereas accumulation of noradrenaline by the 6th-8th day occurred on account of humoral factors.


Subject(s)
Aqueous Humor/physiology , Catecholamines/analysis , Eye/innervation , Sympathetic Nervous System/physiology , Animals , Cats , Ciliary Body/analysis , Epinephrine/analysis , Intraocular Pressure , Iris/analysis , Norepinephrine/analysis , Sympathectomy
19.
Acta Physiol Scand ; 111(4): 435-40, 1981 Apr.
Article in English | MEDLINE | ID: mdl-7304205

ABSTRACT

The adrenergic system of the beluga, Huso huso, was studied by glyoxylic acid fluorescence histochemistry, analyses of catecholamine content in various organs and studies of the effects of acetylcholine and adrenaline on isolated strip preparations from blood vessels, spleen, atrium and ventricle. Chromaffin cells were found mainly in the walls of the posterior cardinal veins, and to some extent also in the wall of the celiaco-mesenteric artery. The plasma concentration of adrenaline was high enough to affect the contraction force of the isolated atrial and ventricular strips, thus adding an adrenergic component to a possible cholinergic inhibitory vagal control of the heart. Fluorescence histochemistry revealed no direct adrenergic innervation of the heart, but blood vessels in the heart and elsewhere received a rich supply of adrenergic nerve terminals. Adrenaline contracted the celiaco-mesenteric artery and the spleen, and produced positive inotropic effects on the paced atrial and ventricular strip preparations. Acetylcholine contracted the ventral aorta and the celiaco-mesenteric artery, and reduced the contraction force of paced ventricular and, especially, atrial preparations. It is concluded that the beluga has a well developed adrenergic system consisting of both chromaffin cells and adrenergic neurons with varicose nerve terminals of the type found in the higher vertebrates.


Subject(s)
Adrenergic Fibers/physiology , Fishes/physiology , Acetylcholine/pharmacology , Animals , Blood Vessels/drug effects , Chromaffin System/physiology , Epinephrine/analysis , Epinephrine/pharmacology , Fluorescence , Heart/drug effects , Histocytochemistry , Neurons/physiology , Norepinephrine/analysis , Spleen/drug effects
SELECTION OF CITATIONS
SEARCH DETAIL
...