Beta decay and other processes in strong electromagnetic fields

We consider effects of the fields of strong electromagnetic waves on various characteristics of quantum processes. After a qualitative discussion of the effects of external fields on the energy spectra and angular distributions of the final-state particles as well as on the total probabilities of the processes (such as decay rates and total cross sections), we present a simple method of calculating the total probabilities of processes with production of non-relativistic charged particles. Using nuclear beta-decay as an example, we study the weak and strong field limits, as well as the field-induced beta-decay of nuclei stable in the absence of the external fields, both in the tunneling and multi-photon regimes. We also consider the possibility of accelerating forbidden nuclear beta-decays by lifting the forbiddeness due to the interaction of the parent or daughter nuclei with the field of a strong electromagnetic wave. It is shown that for currently attainable electromagnetic fields all effects on total beta-decay rates are unobservably small.Comment: LaTeX, 30 pages, 2 figures. Invited contribution to the special issue of Yadernaya Fizika dedicated to the centennial anniversary of birthday of A.B. Migdal. V2: references adde

Динамика иммунного ответа слизистой оболочки долевого бронха у больных пневмонией

A quantitative composition of the immunocompetent cell subpopulations in mucous membrane of a lobar bronchus was studied in pneumonia patients according to the illness course. Features of the cell infiltrate composition in the proper lamina were revealed and a phenotypic characteristic of interepithelial lymphocytes in the lobar bronchus mucosa was found.Изучали количественный состав субпопуляций иммунокомпетентных клеток слизистой оболочки долевого бронха у больных пневмонией в динамике болезни. Выявили особенности состава клеточного инфильтрата собственной пластинки и определили фенотипическую характеристику межэпителиальных лимфоцитов слизистой оболочки долевого бронха в динамике пневмонии

Efficacy of Videoendoscopic Inguinal Femoral Lymphadenectomy for Management of Metastatic Skin Melanoma

Aim. Assessment of the utility and advantage of videoendoscopic inguinal femoral lymphadenectomy (VE-LAD) over the standard open technique (OLAD) in patients with malignant skin melanoma and metastatic lesions of regional inguinal and/or femoral lymph nodes.Materials and methods. The Saint-Petersburg Clinical Research Centre for Specialty Medical Aid in Oncology managed 86 inguinal femoral LADs in melanoma patients over 2013–2016. VE-LAD was rendered in 48 (54.7 %) cases, and OLAD otherwise.Results and discussion. A total of 72 patients were included in the study. VE-LAD was performed in 48 (54.7 %) cases, and OLAD otherwise. An average VE-LAD duration was 90 (60 to 160) min. Severe complications were observed in 4/48 (8 %) VE-LAD and 16/24 (66 %) OLAD cases, which reveals a significantly lower complication rate in the study cohort (chi-square p > 0.000). Lymphorrhoea was shorter in the study cohort (> 7 days in 5 patients vs. 3/24 and > 14 days only in 11/24 OLAD cases; chi-square p > 0.000). No significant differences in relapse-free survival were observed between the cohorts, with higher absolute values of 22.6 months in the VE-LAD (95 % CI 14.8–30.4, p = 0.087) vs. 9.4 months (95 % CI 0.0–18.9, p = 0.087) in OLAD cohort. A median OS was 52.3 months (95 % CI 30.5–74.1, p = 0.996) in the VE-LAD vs. 39.9 months (95 % CI 30.6–49.2, p = 0.996) in OLAD cohort.Conclusion. Videoendoscopic inguinal femoral lymphadenectomy allows a radical inguinal femoral lymph node removal alike in conventional surgical dissection. Our results indicate the method performance towards reduced postoperative wound complications. The oncological indicators are comparable to the traditional surgery cohort

Incidence of Synchronous Multiple Primary Melanoma in Patients with Solitary Melanoma: a Prospective Comparative Study

Background. Malignant melanoma is steadily exaggerating over the recent decades. Nonetheless, improved systemic therapies have substantially increased life expectancy in patients with a locally advanced or disseminated disease. Higherincidence recurrent melanocytic skin lesions become essentially problematic and require more attention and control.Aim. Cross-survey on the incidence of synchronous multiple primary melanomas in patients with solitary melanoma and those with other operable solid tumours.Materials and methods. A total of 289 patients with suspected malignant pigmented skin melanoma were included in the survey. Patients were divided in two cohorts by the presence of primary skin melanoma and its tractability for radical excision. Patients with operable melanoma comprised the study cohort, and those with other solid tumours were the control.Results and discussion. The survey covered 289 patients, with 148 in the study and 141 in the control cohort. The study148 patients revealed 112 malignant pigmented melanomas, but none in the control cohort. A chi-square statistical analysis of clinical values in single and multiple melanoma cases showed a slightly higher prevalence of first-visit melanomas in patients with synchronous tumours (30% pT4 — p = 0.007).Conclusion. The observed 10% rate of second melanoma in the study cohort and a zero melanoma incidence in the control support the alternative hypothesis of a higher rate of newly detected melanomas in primarily diagnosed melanoma patients vs. those with solid tumours

Половой диморфизм структурно-функциональных изменений мозга в раннем постреанимационном периоде после остановки сердца

The investigation was undertaken to study early postresuscitative sexual differences in cerebral structural and functional changes 12 min after cardiac arrest in albino rats. There were great sexual differences in orientative-investigating behavior and anxiety before, as well as neurological recovering processes after clinical death, without distinctions in cardiopul-monary resuscitative processes and postresuscitative mortality. Common changes in the content of peptide substances having a molecular weight of as high as 5 kDa in the brain tissue and gender-associated features were revealed in the early postoperative period. The baseline increased behavioral activity and a rapid postresuscitative recovery of females, unlike males, are associated with the early postresuscitative development of neurodystrophic and degenerative changes in the neuronal populations of the hippocampus and cerebellum.Цель работы — изучение половых различий структурно-функциональных изменений мозга в раннем постреанимационном периоде после 12-мин остановки сердца у белых крыс. Установлены выраженные половые различия ориентировочно-исследовательского поведения и тревожности до опыта, а так же процессов восстановления неврологического статуса после клинической смерти при отсутствии отличий в процессах сердечно-легочной реанимации и постреанимационной летальности. В раннем постреанимационном периоде выявлены общие изменения содержания веществ пептидной природы с молекулярной массой до 5 кДа в ткани мозга и особенности, связанные с полом. Исходно повышенная поведенческая активность и быстрое постреанимационное восстановление самок по сравнению с самцами сопряжены с ранним развитием после оживления нейродистрофических и дегенеративных изменений нейронных популяций гиппокампа и мозжечка

Comprehensive Screening for COVID-19 at St. Petersburg Oncology Centre

Background. Clinical reports on the coronavirus disease 2019 (COVID-19) suggest its higher incidence and worse outcomes in cancer patients. Considering a rapid pace of the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) pandemic, more data on the risk of contagion and syndrome course is required with this patient group.Aim. Estimation of the infection rate in cancer patients managed at the Oncology Centre.Materials and methods. This retrospective study included cancer patients managed at the Oncology Centre between 9 April 2020 and 27 May 2020 and routinely tested for SARS-CoV-2 in polymerase chain reaction (PCR) assays and/or COVID-19 in chest computed tomography (CT).Results and discussion. A total of 2,628 patients were included in the study, with 119 (4.5 %) confirmed to have COVID-19; 45/119 were PCR-positive, 95/119 had viral pneumonia in CT, 21/119 were positive for both tests. A total of 47.9 % cases were asymptomatic, 11.8 % revealed a mild single-symptom disease. COVID-19 ended in death in 2 (2.5 %) of 80 cases with a known outcome. In PCR results of both patient and staff screening, the virus detection rate was 3.0 % and 2.4 %, respectively (p = 0.33).Conclusion. A COVID-19 screening revealed no significant difference in the risk of contagion between cancer patients and staff of the Oncology Centre. PCR tests may perform false negative for COVID-19 in cancer patients and should be coupled with CT scanning. The infection is asymptomatic or clinically mild in most other cases

Lectin-like bacteriocins from pseudomonas spp. utilise D-rhamnose containing lipopolysaccharide as a cellular receptor

Lectin-like bacteriocins consist of tandem monocot mannose-binding domains and display a genus-specific killing activity. Here we show that pyocin L1, a novel member of this family from Pseudomonas aeruginosa, targets susceptible strains of this species through recognition of the common polysaccharide antigen (CPA) of P. aeruginosa lipopolysaccharide that is predominantly a homopolymer of d-rhamnose. Structural and biophysical analyses show that recognition of CPA occurs through the C-terminal carbohydrate-binding domain of pyocin L1 and that this interaction is a prerequisite for bactericidal activity. Further to this, we show that the previously described lectin-like bacteriocin putidacin L1 shows a similar carbohydrate-binding specificity, indicating that oligosaccharides containing d-rhamnose and not d-mannose, as was previously thought, are the physiologically relevant ligands for this group of bacteriocins. The widespread inclusion of d-rhamnose in the lipopolysaccharide of members of the genus Pseudomonas explains the unusual genus-specific activity of the lectin-like bacteriocins

Production of phi mesons at mid-rapidity in sqrt(s_NN) = 200 GeV Au+Au collisions at RHIC

We present the first results of meson production in the K^+K^- decay channel from Au+Au collisions at sqrt(s_NN) = 200 GeV as measured at mid-rapidity by the PHENIX detector at RHIC. Precision resonance centroid and width values are extracted as a function of collision centrality. No significant variation from the PDG accepted values is observed. The transverse mass spectra are fitted with a linear exponential function for which the derived inverse slope parameter is seen to be constant as a function of centrality. These data are also fitted by a hydrodynamic model with the result that the freeze-out temperature and the expansion velocity values are consistent with the values previously derived from fitting single hadron inclusive data. As a function of transverse momentum the collisions scaled peripheral.to.central yield ratio RCP for the is comparable to that of pions rather than that of protons. This result lends support to theoretical models which distinguish between baryons and mesons instead of particle mass for explaining the anomalous proton yield.Comment: 326 authors, 24 pages text, 23 figures, 6 tables, RevTeX 4. To be submitted to Physical Review C as a regular article. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy

A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.Comment: Published in Physical Review Letter