27 research outputs found

    First πK\pi K atom lifetime and πK\pi K scattering length measurements

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    The results of a search for hydrogen-like atoms consisting of πK±\pi^{\mp}K^{\pm} mesons are presented. Evidence for πK\pi K atom production by 24 GeV/c protons from CERN PS interacting with a nickel target has been seen in terms of characteristic πK\pi K pairs from their breakup in the same target (178±49178 \pm 49) and from Coulomb final state interaction (653±42653 \pm 42). Using these results the analysis yields a first value for the πK\pi K atom lifetime of τ=(2.51.8+3.0)\tau=(2.5_{-1.8}^{+3.0}) fs and a first model-independent measurement of the S-wave isospin-odd πK\pi K scattering length a0=13a1/2a3/2=(0.110.04+0.09)Mπ1\left|a_0^-\right|=\frac{1}{3}\left|a_{1/2}-a_{3/2}\right|= \left(0.11_{-0.04}^{+0.09} \right)M_{\pi}^{-1} (aIa_I for isospin II).Comment: 14 pages, 8 figure

    Investigation of K+KK^+K^- pairs in the effective mass region near 2mK2m_K

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    The DIRAC experiment at CERN investigated in the reaction p(24 GeV/c)+Ni\rm{p}(24~\rm{GeV}/c) + Ni the particle pairs K+K,π+πK^+K^-, \pi^+ \pi^- and ppˉp \bar{p} with relative momentum QQ in the pair system less than 100 MeV/c. Because of background influence studies, DIRAC explored three subsamples of K+KK^+K^- pairs, obtained by subtracting -- using time-of-flight (TOF) technique -- background from initial QQ distributions with K+KK^+K^- sample fractions more than 70\%, 50\% and 30\%. The corresponding pair distributions in QQ and in its longitudinal projection QLQ_L were analyzed first in a Coulomb model, which takes into account only Coulomb final state interaction (FSI) and assuming point-like pair production. This Coulomb model analysis leads to a K+KK^+K^- yield increase of about four at QL=0.5Q_L=0.5 MeV/c compared to 100 MeV/c. In order to study contributions from strong interaction, a second more sophisticated model was applied, considering besides Coulomb FSI also strong FSI via the resonances f0(980)f_0(980) and a0(980)a_0(980) and a variable distance rr^* between the produced KK mesons. This analysis was based on three different parameter sets for the pair production. For the 70\% subsample and with best parameters, 3680±3703680\pm 370 K+KK^+K^- pairs was found to be compared to 3900±4103900\pm 410 K+KK^+K^- extracted by means of the Coulomb model. Knowing the efficiency of the TOF cut for background suppression, the total number of detected K+KK^+K^- pairs was evaluated to be around 40000±10%40000\pm 10\%, which agrees with the result from the 30\% subsample. The K+KK^+K^- pair number in the 50\% subsample differs from the two other values by about three standard deviations, confirming -- as discussed in the paper -- that experimental data in this subsample is less reliable

    Evidence for πK\pi K-atoms with DIRAC

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    We present evidence for the first observation of electromagnetically bound π±K\pi^\pm K^\mp-pairs (πK\pi K-atoms) with the DIRAC experiment at the CERN-PS. The πK\pi K-atoms are produced by the 24 GeV/c proton beam in a thin Pt-target and the π±\pi^\pm and KK^\mp-mesons from the atom dissociation are analyzed in a two-arm magnetic spectrometer. The observed enhancement at low relative momentum corresponds to the production of 173 ±\pm 54 πK\pi K-atoms. The mean life of πK\pi K-atoms is related to the s-wave πK\pi K-scattering lengths, the measurement of which is the goal of the experiment. From these first data we derive a lower limit for the mean life of 0.8 fs at 90% confidence level.Comment: 15 pages, 9 figure

    Discovery of potential ovarian cancer biomarkers using low molecular weight blood plasma proteome profiling by mass spectrometry

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    At present, there is no screening test for the early detecting and monitoring of ovarian cancer, one of the most lethal form of gynaecological malig- nancy in the worldwide. In this study, the new methodology for the search of tumor markers of ovarian cancer, involving profiling the low-molec- ular blood plasma proteomes, is developed, unified and approved. The given approach included three basic components: pre-preparation of samples, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and bioinformatics software for mass spectral data process- ing. Opportunities and prospects of the developed approach for the detection of potential ovarian cancer markers were shown. For search of po- tential tumor markers, screening of 40 blood plasma samples from ovarian cancer patients and 48 control samples were carried out. As a result of the present research, peptides/polypeptides which can be used in future for detecting this pathology were found out

    Use of cellular biotechnologies in treatment metastatic pericarditis at patients with tumors of female reproductive system

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    Malignant pericardial effusions often arise in patients with breаst cancer and ovarian cancer. Sistem antitumor therapy is uneffective in gen- erally and causes side effects. Here we show that intrapericardial interleukin-2 with allogenеc lymphokine-activated killers and interleukin-2 immunotherapy demonstrated the high efficacy in threatment of breаst and ovarian cancer patients with malignant pericardial effusions. The objective effect was 92.3 % аnd 90.0 % accordingly. These results indicates that intrapericardial immunotherapy might be one of the stages of combined treatment of such group of patients. The suggested type of biotherapy increases the survival and life quality of patients

    Imunotherapy opportunities in ovarian cancer

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    In the last decade, accumulated evidence in favor of that ovarian cancer is an immunogenic tumor. Immunotherapy is aimed at stimulating the innate and adaptive immunity, may cause an effective response in patients with ovarian cancer. Various approaches immunotherapy include cytokinetherapy, use of monoclonal antibodies and cell therapy

    The Level of Meningococcal Carriage and Genotyping of N. meningitidis Strains in the Group of Labor Migrants

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    Relevance. Population migration can play a crucial role in the spread of invasive strains of meningococcus, initiating outbreaks of meningococcal infection, and changing the incidence at the local level.Aim. To assess the prevalence of meningococcal carriage among migrants arriving in Moscow and to characterize the antigenic and genetic properties of carrier strains of meningococcus.Materials and methods. The study was conducted in March 2020 at the bases of the Multifunctional Migration Center of Moscow and the Federal Budget Institution of Science «Central Research Institute of Epidemiology». Samples of nasopharyngeal mucus were collected from 352 people. Nasopharyngeal strains of meningococcus were identified and identified using microbiological, serological, and molecular biological methods.Results. The overall level of the carriage was 5.7%. Of the twenty selected strains, 10 have a serogroup defined: Y – 5 strains, W - 3, A, and B – 1 each. The obtained genetic and antigenic characteristics do not allow talking about the import into the RF of representatives of known hypervirulent clonal complexes. In this study, strains were identified that are part of the clonal complex ST-175 complex, which has not been previously described in the Russian Federation.Conclusion. It seems promising to continue the dynamic monitoring of carriage of meningococcus in various groups, including among people entering the country to obtain a migration patent, as well as identifying risk factors for acquiring carriage. The data obtained will supplement current information on the incidence of the generalized form of meningococcal infection and will be crucial for determining the epidemiology at the country level, the population groups responsible for the transmission of the disease, and the need for targeted vaccination
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