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

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

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

The DIRAC experiment at CERN investigated in the reaction $\rm{p}(24~\rm{GeV}/c) + Ni$ the particle pairs $K^+K^-, \pi^+ \pi^-$ and $p \bar{p}$ with relative momentum $Q$ in the pair system less than 100 MeV/c. Because of background influence studies, DIRAC explored three subsamples of $K^+K^-$ pairs, obtained by subtracting -- using time-of-flight (TOF) technique -- background from initial $Q$ distributions with $K^+K^-$ sample fractions more than 70\%, 50\% and 30\%. The corresponding pair distributions in $Q$ and in its longitudinal projection $Q_L$ 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 $K^+K^-$ yield increase of about four at $Q_L=0.5$ 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 $f_0(980)$ and $a_0(980)$ and a variable distance $r^*$ between the produced $K$ mesons. This analysis was based on three different parameter sets for the pair production. For the 70\% subsample and with best parameters, $3680\pm 370$ $K^+K^-$ pairs was found to be compared to $3900\pm 410$ $K^+K^-$ extracted by means of the Coulomb model. Knowing the efficiency of the TOF cut for background suppression, the total number of detected $K^+K^-$ pairs was evaluated to be around $40000\pm 10\%$, which agrees with the result from the 30\% subsample. The $K^+K^-$ 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

We present evidence for the first observation of electromagnetically bound $\pi^\pm K^\mp$-pairs ($\pi K$-atoms) with the DIRAC experiment at the CERN-PS. The $\pi K$-atoms are produced by the 24 GeV/c proton beam in a thin Pt-target and the $\pi^\pm$ and $K^\mp$-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 $\pi K$-atoms. The mean life of $\pi K$-atoms is related to the s-wave $\pi K$-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

ЗАБОЛЕВАЕМОСТЬ ЭНТЕРОВИРУСНОЙ ИНФЕКЦИЕЙ И ОСОБЕННОСТИ ЦИРКУЛЯЦИИ НЕПОЛИОМИЕЛИТНЫХ ЭНТЕРОВИРУСОВ НА НЕКОТОРЫХ ТЕРРИТОРИЯХ РОССИИ В 2017 ГОДУ

Aim: Characteristics of enterovirus infection morbidity and study of peculiarities of enterovirus circulation on some territories of Russia in 2017. Materials and methods: We investigated more than 5000 samples from the patients with enterovirus infection. The isolation and identification of enteroviruses were conducted by virological method and by partial sequencing of the genome region VP1. Phylogenic trees were constructed according to the method of Bayesian Monte Carlo Markov Chain. Results: Epidemic process and clinical picture of enterovirus infection were not the same on different territories. Peculiarities of the circulation of different types of enteroviruses on the territories were also different. In Saratov region 65% of cases were represented by enterovirus meningitis. In Murmansk region and in the Komi Republic enterovirus infection with exanthema prevailed, 95% and 60% correspondingly. In Saratov region enterovirus ECHO18 was the etiological agent of enterovirus meningitis. In Murmansk region and in the Komi Republic the cases were connected mainly with Coxsackieviruses A6. The strains of enterovirus ECHO18 were distributed to three clusters. The strains which provoked enterovirus meningitis in Saratov region belonged to cluster 3, they were formed separately from other strains of this enterovirus type and differed from the stains of ECHO18 which circulated in the North-West of Russia. The strains of Coxsackieviruses A6 identified in the North-West of Russia belonged to three sub-genotypes 5, 6, 8 of pandemic genotype of CoxsackievirusesA6. The majority of the strains belonged to sub-genotypes 6 and 8 which in 2017 dominated in the structure of Coxsackieviruses A6 in the North-West of Russia and in Russia. Conclusion: Epidemic peaks of enterovirus infection represented by different clinical forms of the disease were provoked by different types of enteroviruses. Enterovirus ECHO18 was the etiological agent of enterovirus meningitis. The main etiological factors of enterovirus infection with exanthema were Coxsackieviruses A6 of different sub-genotypes.Цель: характеристика заболеваемости энтеровирусной инфекцией и изучение особенностей циркуляции неполиомиелитных энтеровирусов на ряде территорий России в 2017 г. Материалы и методы: исследовано более 5000 проб фекалий от больных энтеровирусной инфекцией. Выделение и идентификацию энтеровирусов проводили вирусологическим методом и путём частичного секвенирования области генома VP1. Филогенетические деревья были построены методом Bayesian Monte Carlo Markov Chain. Результаты: течение эпидемического процесса и клинические проявления энтеровирусной инфекции на разных территориях отличались. Особенности циркуляции энтеровирусов разных типов на территориях также были разными. В Саратовской области 65% заболеваний были представлены энтеровирусным менингитом. В Мурманской области и в Республике Коми преобладали экзантемные формы энтеровирусной инфекции, составившие 95% и 60% соответственно. В Саратовской области этиологическим фактором энтеровирусного менингита оказался энтеровирус ЕСНО 18. В Мурманской области и в Республике Коми заболевания были обусловлены в основном Coxsackievirus А6. Штаммы энтеровируса ЕСНО 18 распределились по трем кластерам. Штаммы, обусловившие заболевания энтеровирусным менингитом в Саратовской области, вошли в кластер 3, они сформировались отдельно от штаммов этого типа вируса и отличались от штаммов ЕСНО18, которые циркулировали на северо-западе России. Штаммы вируса Coxsackievirus А6, идентифицированные на северо-западе России, относились к трем субгенотипам пандемического генотипа вируса Coxsackievirus А6 – 5, 6 и 8. Большинство штаммов относились к субгенотипам 6 и 8, которые в 2017 г. доминировали в структуре Coxsackieviruses А6 на северо-западе России и в Российской Федерации в целом. Заключение: эпидемические подъемы заболеваемости энтеровирусной инфекцией, представленной различными клиническими формами, были обусловлены разными типами энтеровирусов. Этиологическим агентом энтеровирусного менингита были энтеровирусы ЕСНО 18. Основным этиологическим фактором экзантемных форм заболевания были Coxsackieviruses A6 разных субгенотипов

Epidemiological Characteristics of Meningococcal Infection in Moscow

Aims. The purpose of this study was to identify current epidemiological features of meningococcal infection in Moscow.Materials and methods. Cases of invasive meningococcal disease in Moscow from 2014 to 2018 and the biomaterial from patients with an invasive meningococcal disease were analyzed.Results. The features of the epidemic process of meningococcal disease in Moscow were revealed: increasing in the incidence rate involving teenagers and young adults into the epidemic process; meningococcal strains of serogroups W and A increased in the etiology of the invasive meningococcal disease; high mortality rate.Conclusions. It seems reasonable to recommend vaccination against meningococcal disease by including adolescents, young adults and persons over 65 years old

Micrometastases identification in malignant tumors

The article reviewed literature data relating to the methods used for detection of single tumor cells in bone marrow, lymph nodes, and peripheral blood. Sensitivity of modern detection methods is analyzed. Despite advances in the development of molecular biology and cytology, until now there is no universal approach to the micrometastases identification, and existing methods optimization are recommended

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

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

Neoadjuvant chemotherapy for advanced ovarian cancer: literature data and in vitro studies

This paper analyzes large amounts of literature data on studies of the efficiency of neoadjuvant chemotherapy (NCT) for advanced ovarian cancer (OC), which is performed prior to standard surgery. Clinical trials have demonstrated that a NCT regimen followed by cytoreductive surgery is less effective than primary cytoreductive one; however, evidence for the benefit of NCT is lacking so far. The authors conducted investigations using the intraoperative material obtained from 17 patients with T3a–cNxM0 OC, who were divided for a comparative examination into 2 groups. Group 1 included OC patents who received NCT; Group 2 comprised OC patients who did not. The tumor cells obtained from the intraoperative material of both groups were able to generate a well-proliferating culture in in vitro experiments. The cultured OC cells were characterized, by analyzing cytological specimens and the functional activity of these cells. It was ascertained that 35 % of the cultured tumor cells from OC retained their resistance to the cytotoxic action of effector cells (autologous lymphocytes) at a target cell/effector cell ratio of 1:5. Thus, both the literature and the experiment provide no unambiguous evidence supporting the fact that NCT before cytoreductive surgery is a better approach than primary surgical treatment. The optimal regimen of NCT, which would be able to enhance its efficiency, remains important