149 research outputs found
Status of Evidence for Neutrinoless Double Beta Decay
The present experimental status in the search for neutrinoless double beta
decay is reviewed, with emphasis on the first indication for neutrinoless
double beta decay found in the Heidelberg-Moscow experiment, giving first
evidence for lepton number violation and a Majorana nature of the neutrinos.
Future perspectives of the field are briefly outlined.Comment: 37 pages, latex, 23 figures, Published in Found. Phys. 32 (2002)
1181-1223 and Presented at Fourth Heidelberg International Conference on Dark
Matter in Astro- and Particle Physics, DARK2002, Cape Town, South Africa, 4 -
9 February, 2002, eds. H.V. Klapdor-Kleingrothaus and R. Viollier,
Springer-Verlag Heidelberg, (2002) 367-403 see Home Page of Heidelberg
Non-Accelerator Particle Physics Group:
http://www.mpi-hd.mpg.de/non_acc/buecher.html#DARK200
Search for neutrinoless double beta decay with enriched 76Ge in Gran Sasso 1990-2003
The results of the HEIDELBERG-MOSCOW experiment which searches with 11 kg of
enriched 76Ge for double beta decay in the GRAN Sasso underground laboratory
are presented for the full running period August 1990 - May 2003. The duty
cycle of the experiment was ~80%, the collected statistics is 71.7 kg y. The
background achieved in the energy region of the Q value for double beta decay
is 0.11 events/ kg y keV. The two-neutrino accompanied half-life is determined
on the basis of more than 100 000 events. The confidence level for the
neutrinoless signal has been improved to 4.2 sigma.Comment: 19 pages, latex, 9 figures, 2 table
First Results from the HDMS experiment in the Final Setup
The Heidelberg Dark Matter Search (HDMS) is an experiment designed for the
search for WIMP dark matter. It is using a special configuration of Ge
detectors, to efficiently reduce the background in the low-energy region below
100 keV. After one year of running the HDMS detector prototype in the Gran
Sasso Underground Laboratory, the inner crystal of the detector has been
replaced with a HPGe crystal of enriched Ge. The final setup started
data taking in Gran Sasso in August 2000. The performance and the first results
of the measurement with the final setup are discussed.Comment: 8 pages, revtex, 7 figures, Home Page of Heidelberg Non-Accelerator
Particle Physics Group: http://www.mpi-hd.mpg.de/non_acc
The use of cytokines in the treatment of cornea inflammatory and dystrophic diseases (review)
Cytokines are unique biologically active substances that form the system of regulation of basic body functions that simultaneously with the nervous and endocrine systems maintain homeostasis under adverse conditions – the introduction of pathogens or violation of the integrity of tissues. Cytokines regulate the amplitude and duration of inflammatory and immune responses, so they are produced and secreted transiently and have a short half-life. These biologically active substances act in very low concentrations. At the same time, the main properties of cytokines are pleiotropy, lack of antigenic specificity, and the ability to form a cascade chain, that allows versatile correction of the spectrum of reparative processes. There are evidences of the possibility of using cytokines in the regeneration of damaged tissues in recent decades. In this connection, a new vector of search for pathogenetically directed ways to improve and restore lost functions using both individual representatives of cytokines and their natural complex is determined. The article reflects the basic information about the influence of cytokines on the development of various diseases of the cornea, as well as the methods of cytokine therapy in the treatment of these pathologies and prospects for their development
Evidence for Neutrinoless Double Beta Decay
The data of the Heidelberg-Moscow double beta decay experiment for the
measuring period August 1990 - May 2000 (54.9813 kg y or 723.44 molyears),
published recently, are analyzed using the potential of the Bayesian method for
low counting rates. First evidence for neutrinoless double beta decay is
observed giving first evidence for lepton number violation. The evidence for
this decay mode is 97% (2.2\sigma) with the Bayesian method, and 99.8% c.l.
(3.1\sigma) with the method recommended by the Particle Data Group. The
half-life of the process is found with the Bayesian method to be T_{1/2}^{0\nu}
= (0.8 - 18.3) x 10^{25} y (95% c.l.) with a best value of 1.5 x 10^{25} y. The
deduced value of the effective neutrino mass is, with the nuclear matrix
elements from [Sta90,Tom91] = (0.11 - 0.56) eV (95% c.l.), with a best
value of 0.39 eV. Uncertainties in the nuclear matrix elements may widen the
range given for the effective neutrino mass by at most a factor 2. Our
observation which at the same time means evidence that the neutrino is a
Majorana particle, will be of fundamental importance for neutrino physics.
PACS. 14.69.Pq Neutrino mass and mixing; 23.40.Bw Weak-interaction and lepton
(including neutrino) aspects 23.40.-s Beta decay; double beta decay; electron
and muon capture.Comment: 14 pages, psfile, 7 figures, Published in Modern Physics Letters A,
Vol. 16, No. 37 (2001) 2409-2420, World Scientific Publishing Company, Home
Page: http://ejournals.wspc.com.sg/mpla/16/1637/S0217732301005825.html, Home
Page of Heidelberg Non-Accelerator Particle Physics Group:
http://www.mpi-hd.mpg.de/non_acc
Searching for the Annual Modulation of Dark Matter signal with the GENIUS-TF experiment
The annual modulation of the recoil spectrum observed in an underground
detector is well known as the main signature of a possible WIMP signal. The
GENIUS-TF experiment, under construction in the Gran Sasso National Laboratory,
can search for the annual modulation of the Dark Matter signal using 40 kg of
naked-Ge detectors in liquid nitrogen. Starting from a set of data simulated
under the hypothesis of modulation and using different methods, we show the
potential of GENIUS-TF for extracting the modulated signal and the expected
WIMP mass and WIMP cross section.Comment: In press, Nuclear Instruments and Methods in Physics Research Section
A: Accelerators, Spectrometers, Detectors and Associated Equipment (2003) and
in Proc. of IDM2002, York Minster, England, 2-6 September, 2002, World
Scientific 200
Modern etiological and pathogenetic aspects of chronic peripheral uveitis
Intermediate uveitis is among most severe forms of endogenous uveitis which is more common in young people, being characterized by minimal clinical manifestations at early stages of the disorder. A significant and, sometimes, irreversible decrease in visual acuity is associated with development of long-term complications of chronic cintermediate uveitis (CIU), i.e., complicating cataracts (in up to 57% of the cases), cystic maular edema developing at a frequency of up to 31%), as well as ophthalmic hypertension and glaucoma (up to 16% of the patients). The incidence rate of CIU is 1.5 per 100,000 per year. The eye, despite its high immune privilege, is susceptible to infectious and inflammatory diseases. Clinical and histopathological data suggest autoimmune origin of CIU associated with possible response to some endogenous antigen of unknown origin. The main effectors of inflammation in peripheral chorioretinal structures are CD4+T lymphocytes, which are found in paravasal infiltrates and vitreoretinal exudates in CIU. An important role in CIU pathogenesis is attributed to IL-6 and IL-8, TNFá, vascular endothelial growth factor (VEGF), and micro-RNAs, which show increased expression in most CIU patients. Impaired state of intestinal bacterial microbiome is a potential trigger of intraocular inflammation. Genetic predisposition for CIU was also revealed, due to polymorphisms of human leukocyte antigens and some other genes. It is necessary to expand and deepen our knowledge on the disease pathogenesis, in order to develop effective pharmacological treatment of CIU. The article is review of literature discussing the modern scientific ideas concerning etiology and mechanisms of the CIU development
Features of the local cytokine profile of patients with bullous keratopathy by using personalized therapy with cellular technologies
Background. Today we have active development of ophthalmic surgery, but the role of cytokines in the pathogenesis of bullous keratopathy of the cornea remains insufficiently studied at present.The aim. To study the dynamics of the local cytokine profile in bullous keratopathy by using personalized treatment with suspension of autologous blood mononuclears.Material and methods. Two groups of patients with bullous keratopathy were formed: the main group (30 people, 30 eyes), who received an intrastromal injection of a suspension of autologous blood mononuclears and comparison (28 people, 28 eyes), who received a course of pharmacotherapy. The level of interleukins (IL) – IL-10, IL-4, IL-6, IL-1ß, transforming growth factor beta-2 (TGF-β2), tumor necrosis factor alpha (TNF-α) was determined in the lacrimal fluid of the patient’s eye by enzyme immunoassay.Results. All patients before treatment showed an increase of IL-1ß in the lacrimal fluid by 3.3 times, IL-6 – by 4.2 times, TNF-α – by 2.0 times (p < 0.05); an increase in the level of IL-4, IL-10 and TGF-β2 by 1.1 times (p > ˂ 0.05). In the main group, after treatment, there was a decrease in IL-1ß by 2.0 times, IL-6 – by 2.1 times and TNF-α – by 1.8 times, and an increase in IL-10 by 1.5 times, IL-4 – by 1.9 times, TGF-β2 – by 1.4 times (p < 0.05), persisting for 12 months. There was a short-term decrease of IL-1ß by 1.7 times, IL-6 and TNF-α – by 1.2 times and an increase of IL-10, IL-4, TGF-β2 by 1.2 times (p >< 0.05) in the comparison group which then reached the initial values. Conclusion. There is an imbalance in the system of pro- and anti-inflammatory cytokines in bullous keratopathy in the lacrimal fluid. Injection of autologous mononuclear cells in the stroma of the cornea reduces the severity of the imbalance of the local cytokine system compared to the course of pharmacotherapy. Key words: bullous keratopathy, cellular technologies, autologous mononuclear leukocytes, cytokines>˂ 0.05), persisting for 12 months. There was a short-term decrease of IL-1ß by 1.7 times, IL-6 and TNF-α – by 1.2 times and an increase of IL-10, IL-4, TGF-β2 by 1.2 times (p ˂ 0.05) in the comparison group which then reached the initial values.Conclusion. There is an imbalance in the system of pro- and anti-inflammatory cytokines in bullous keratopathy in the lacrimal fluid. Injection of autologous mononuclear cells in the stroma of the cornea reduces the severity of the imbalance of the local cytokine system compared to the course of pharmacotherapy
Advanced Laboratory Methods for Detecting Yellow Fever Pathogen
Yellow fever is an acute infectious disease of viral nature, the causative agent of which is vector-borne –is transmitted through the bites of infected mosquitoes. Massive epidemics caused by the yellow fever virus are observed in the countries of Africa, South and Central America annually. Imported cases are also registered in non-endemic territories. The review presents the currently available data on the distribution, structure and classification of the yellow fever virus, the identification of its genetic variants depending on the geographical distribution, as well as modern methods of detection and identification of the pathogen in samples taken from sick and dead people. It considers the possibility of using virological, immunoserological and molecular-genetic methods for the diagnosis of yellow fever in different periods from the onset of the disease and in retrospective studies. The lists of diagnostic drugs of domestic and foreign production for the detection of agent markers (antigen, RNA), as well as specific antibodies of IgM and IgG classes, approved for use on the territory of the Russian Federation, are provided. The relevance of further development, improvement and introduction into laboratory practice of reagent kits that allow to detect the yellow fever virus in samples from sick people in a short time, with high efficiency and specificity is demonstrated. This will help to establish a diagnosis promptly and conduct timely anti-epidemic measures, as well as to determine the level of the population stratum immune to the pathogen in endemic regions and evaluate the effectiveness of immunization for the vaccinated contingent
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