A repeating fast radio burst source in a globular cluster.

Fast radio bursts (FRBs) are flashes of unknown physical origin1. The majority of FRBs have been seen only once, although some are known to generate multiple flashes2,3. Many models invoke magnetically powered neutron stars (magnetars) as the source of the emission4,5. Recently, the discovery6 of another repeater (FRB 20200120E) was announced, in the direction of the nearby galaxy M81, with four potential counterparts at other wavelengths6. Here we report observations that localized the FRB to a globular cluster associated with M81, where it is 2 parsecs away from the optical centre of the cluster. Globular clusters host old stellar populations, challenging FRB models that invoke young magnetars formed in a core-collapse supernova. We propose instead that FRB 20200120E originates from a highly magnetized neutron star formed either through the accretion-induced collapse of a white dwarf, or the merger of compact stars in a binary system7. Compact binaries are efficiently formed inside globular clusters, so a model invoking them could also be responsible for the observed bursts.

Compact radio emission indicates a structured jet was produced by a binary neutron star merger.

The binary neutron star merger event GW170817 was detected through both electromagnetic radiation and gravitational waves. Its afterglow emission may have been produced by either a narrow relativistic jet or an isotropic outflow. High-spatial-resolution measurements of the source size and displacement can discriminate between these scenarios. We present very-long-baseline interferometry observations, performed 207.4 days after the merger by using a global network of 32 radio telescopes. The apparent source size is constrained to be smaller than 2.5 milli-arc seconds at the 90% confidence level. This excludes the isotropic outflow scenario, which would have produced a larger apparent size, indicating that GW170817 produced a structured relativistic jet. Our rate calculations show that at least 10% of neutron star mergers produce such a jet.

Influence of the vaccine Polyvaccinum mite on the nasal mucosa.

The necessity of prolonged administration of the vaccine Polyvaccinum prompted this study on the effect of the preserving agent on the nasal mucosa. Buffered physiologic saline solution containing 0.1--0.4% phenol, and the vaccine containing 0.1--0.4% phenol or 0.01% merthiolate were applied for 12 weeks on the nasal mucosa of rabbits. The nasal mucosa, parenchymal organs and adrenals were studied macroscopically and histologically, and immunologic studies were made. On the basis of the results, preservation of Polyvaccinum mite with 0.4% phenol is suggested.

Structural properties of native and sonicated cinerean, a beta- (1-->3) (1-->6)-D-glucan produced by Botrytis cinerea.

Cinerean, the extracellular beta-(1-->3) (1-->6)-D-glucan of the fungus Botrytis cinerea was studied. Electron micrographs of the native polysaccharide revealed quasi-endless fibrils with an estimated diameter of ca. 1.5 nm. A particle mass of 10(9)-10(10) daltons was determined from dilute solutions by low-angle laser light scattering. Sonication of increasing duration led to fragmentation of the native polymer with an approximately exponential decrease of mass in the range of average molecular masses between 250,000 and 50,000 daltons. Shadowed by platinum, cinerean fibril fragments with a weight-average molecular mass of 172,000 +/- 3000 daltons could be characterized from electron micrographs as a distribution of rods of most probable length of 45 nm and an average length of 72 nm. Small-angle X-ray scattering confirmed the fibrillar structure of the native cinerean and the rodlike structure of sonicated cinerean. A rod diameter of 1.9 +/- 0.2 nm and a mass per unit length of 2250 +/- 490 daltons/nm were found. The latter is in agreement with the value of 1830 daltons/nm calculated from the length distribution determined from the electron micrographs. These data-especially the mass per unit length-suggest a quaternary structure for the polysaccharide. Such a structure would explain the rigidity of the rods which, in turn, is responsible for the characteristic phase separation behaviour in aqueous solutions observed by nephelometry and viscometry.

Biological accessibility of calcitonin and osteocalcin marked 125J for rats.

Biological accessibility of calcitonin and osteocalcin marked 125J for rast. In this study we estimated the biological accessibility and the degree of biological accessibility of calcitonin in relation to highly specific marker-osteocalcin after a single intraperitoneal administration. We showed mean values of biopharmaceutical parameters for the analysed hormones.

[Initial experience with a new type of high energy neodymium laser in correcting stenosis of the airway]. / Pierwsze doswiadczenia z zastosowaniem nowego lasera neodymowego w leczeniu zwezen dróg oddechowych.

The aim of the study was to assess the use of a new Nd:YAG laser--mediLas fibertom--in correcting malignant and benign stenoses of the airways. Eighteen patients were included in the study. In 9 these were caused by malignant tumors, in 3 by nonmalignant tumors, in 6 by post-inflammatory stenoses of the airways. Altogether 99 laser sessions were carried out. In patients with malignant diseases complete recanalization was achieved in 6 patients, in 2 partial. One patients did not benefit form the laser procedure. In patients with benign tumors complete recanalization was achieved in all of the patients. In 5 out of 6 patients the post inflammatory stenosis was corrected. Satisfactory results observed after the second, fourth and one year after the initial laser procedure encourage to use this from of therapy in cases of malignant and nonmalignant narrowing of the airways.

Multimedial data base and management system for self-education and testing the students' knowledge on pathomorphology.

The composition assumed our experience in creating and using multimedial data base of examination questions and management system, which is used for. This system is implemented on microcomputers compatible with IBM PC and works in network system Net Ware 3.11. The test questions exceeded 2000 until now. The packet consists of the two functionally individual programs: ASSISTANT, which is the administrator for the databases, and EXAMINATOR which is the executive program. This system enables to use text files and add images to each question, which are adjusted to display on standard graphics devices (VGA). Standard format of the notation files enables to elaborate the results in order to estimate the scale of answers and to find correlations between the results.