Abstract The hybrid design of the Pierre Auger Observatory allows for the measurement of the properties of extensive air showers initiated by ultra-high energy cosmic rays with unprecedented ...precision. By using an array of prototype underground muon detectors, we have performed the first direct measurement, by the Auger Collaboration, of the muon content of air showers between $$2\times 10^{17}$$ 2 × 10 17 and $$2\times 10^{18}$$ 2 × 10 18 eV. We have studied the energy evolution of the attenuation-corrected muon density, and compared it to predictions from air shower simulations. The observed densities are found to be larger than those predicted by models. We quantify this discrepancy by combining the measurements from the muon detector with those from the Auger fluorescence detector at $$10^{{17.5}}\, {\mathrm{eV}} $$ 10 17.5 eV and $$10^{{18}}\, {\mathrm{eV}} $$ 10 18 eV . We find that, for the models to explain the data, an increase in the muon density of $$38\%$$ 38 % $$\pm 4\% (12\%)$$ ± 4 % ( 12 % ) $$\pm {}^{21\%}_{18\%}$$ ± 18 % 21 % for EPOS-LHC , and of $$50\% (53\%)$$ 50 % ( 53 % ) $$\pm 4\% (13\%)$$ ± 4 % ( 13 % ) $$\pm {}^{23\%}_{20\%}$$ ± 20 % 23 % for QGSJetII-04 , is respectively needed.
Takotsubo cardiomyopathy (TCM) is a condition characterized by reversible left ventricular dysfunction. TCM usually has a good prognosis but, in rare situations, it can be associated with ...life-threatening arrhythmias. We report a case and the management of TCM with a high-grade AV block and QT prolongation followed by ventricular fibrillation. Keywords: takotsubo cardiomyopathy, high-grade atrioventricular block, ventricular fibrillation, permanent pacemaker
A prospective study of 1,144 infants and their families was performed. Smoking and family histories were evaluated with respect to the incidence of lower respiratory disease during the first year of ...life. It was found that (1) tracheitis and bronchitis occurred significantly more frequently in infants exposed to cigarette smoke in the home, (2) maternal smoking imposed greater risks upon the infant than paternal smoking, (3) occurrence of neither tracheitis nor bronchitis showed a consistent relationship to the number of cigarettes smoked, (4) a family history that was positive for respiratory illness (chronic cough or bronchitis) significantly influenced the incidence of bronchitis, (5) too few cases of laryngitis and pneumonia were seen to warrant any opinions regarding the adverse influence of either smoking or a family history that was positive for respiratory illness, and (6) occurrence of bronchiolitis was not affected by the presence of a smoker nor influenced by a family history that was positive for respiratory illness. It is concluded that passive smoking is dangerous to the health of infants and that infants born to families with a history that is positive for respiratory illness (chronic cough or bronchitis) are at risk of developing bronchitis.
The effect of duration of orally administered penicillin V potassium on the bacteriologic and clinical cure of group A streptococcal pharyngitis was evaluated. One hundred ninety-one middle-class ...patients received either seven days (96 patients) or ten days (95 patients) of therapy. Compliance with taking penicillin was assessed by multiple methods, including penicillinuria. Throat cultures were obtained during therapy and three times in the three weeks after therapy. M-precipitin and T-agglutinin typing were done on paired isolates of group A streptococci from patients who had recurrences. Patients treated for seven days had a significantly greater failure rate (30/96 31%) compared with patients receiving ten days of penicillin (17/95 18%). Compliance rates were high; 66% to 81% of patients showed penicillinuria throughout the study period. Treatment failure was not a function of poor compliance in either treatment group. The data support the current recommendation for ten full days of penicillin therapy and suggest that persistence of streptococci in the throat after adequate therapy may be common.
Objective
The aim of this study is to evaluate if it is necessary to remove all the radioactive sentinel lymph nodes (SLNs) not seen on lymphoscintigraphy in order to accurately stage breast cancer ...patients.
Material and methods
From March 1999 to March 2006, SLN biopsy was performed in 461 patients. All patients were only injected with radioisotope. Lymphoscintigraphy was performed in all the patients. The mean number of SLNs removed was 2.1 (range 1–15).
Results
The SLN was positive in 133 patients (28.8%). Lymphoscintigraphy accurately predicted the number of SLNs identified intraoperatively in 243 patients (52.7%). In 175 patients (37.9%) there were more SLNs identified intraoperatively than were seen on lymphoscintigraphy. In 11 (6.2%) of these 175 patients, additional SLNs identified intraoperatively harboured metastasis. Type of injection, need for a second injection, tumour location and age were not identified as statistically significantly associated with additional positive SLNs identified intraoperatively and not seen on lymphoscintigraphy.
Conclusions
Lymphoscintigraphy does not accurately predict the number of SLNs identified intraoperatively, this number being underestimated. Surgeons should remove all radioactive SLNs to improve the detection of positive SLNs.
Eur. Phys. J. C (2021) 81:966 We present a measurement of the cosmic-ray spectrum above 100\,PeV using the
part of the surface detector of the Pierre Auger Observatory that has a spacing
of 750~m. An ...inflection of the spectrum is observed, confirming the presence of
the so-called \emph{second-knee} feature. The spectrum is then combined with
that of the 1500\,m array to produce a single measurement of the flux, linking
this spectral feature with the three additional breaks at the highest energies.
The combined spectrum, with an energy scale set calorimetrically via
fluorescence telescopes and using a single detector type, results in the most
statistically and systematically precise measurement of spectral breaks yet
obtained. These measurements are critical for furthering our understanding of
the highest energy cosmic rays.
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