A short gamma-ray burst apparently associated with an elliptical galaxy at redshift z = 0.225

Gamma-ray bursts (GRBs) come in two classes: long (> 2 s), soft-spectrum bursts and short, hard events. Most progress has been made on understanding the long GRBs, which are typically observed at high redshift (z approximately 1) and found in subluminous star-forming host galaxies. They are likely to be produced in core-collapse explosions of massive stars. In contrast, no short GRB had been accurately (< 10') and rapidly (minutes) located. Here we report the detection of the X-ray afterglow from--and the localization of--the short burst GRB 050509B. Its position on the sky is near a luminous, non-star-forming elliptical galaxy at a redshift of 0.225, which is the location one would expect if the origin of this GRB is through the merger of neutron-star or black-hole binaries. The X-ray afterglow was weak and faded below the detection limit within a few hours; no optical afterglow was detected to stringent limits, explaining the past difficulty in localizing short GRBs.     

A new gamma-ray burst classification scheme from GRB 060614

Gamma-ray bursts (GRBs) are known to come in two duration classes, separated at approximately 2 s. Long-duration bursts originate from star-forming regions in galaxies, have accompanying supernovae when these are near enough to observe and are probably caused by massive-star collapsars. Recent observations show that short-duration bursts originate in regions within their host galaxies that have lower star-formation rates, consistent with binary neutron star or neutron star-black hole mergers. Moreover, although their hosts are predominantly nearby galaxies, no supernovae have been so far associated with short-duration GRBs. Here we report that the bright, nearby GRB 060614 does not fit into either class. Its approximately 102-s duration groups it with long-duration GRBs, while its temporal lag and peak luminosity fall entirely within the short-duration GRB subclass. Moreover, very deep optical observations exclude an accompanying supernova, similar to short-duration GRBs. This combination of a long-duration event without an accompanying supernova poses a challenge to both the collapsar and the merging-neutron-star interpretations and opens the door to a new GRB classification scheme that straddles both long- and short-duration bursts.     

Acyl-kallikrein; a delivery system for the kinin-liberating enzyme

Summary Glandular kallikrein can be temporarily acylated at the active centre by 4-amidinophenyl benzoates. The time course of reactivation depends on the nature of the acyl group introduced. Benzoyl kallikrein was used as a delivery system for kallikrein in vivo. In rabbits, bolus injection of the acylated enzyme caused a long-lasting drop in blood pressure due to sustained kinin liberation.     

Acyl-kallikrein; a delivery system for the kinin-liberating enzyme

Glandular kallikrein can be temporarily acylated at the active centre by 4-amidinophenyl benzoates. The time course of reactivation depends on the nature of the acyl group introduced. Benzoyl kallikrein was used as a delivery system for kallikrein in vivo. In rabbits, bolus injection of the acylated enzyme caused a long-lasting drop in blood pressure due to sustained kinin liberation.     

An infrared flash contemporaneous with the gamma-rays of GRB 041219a

The explosion that results in a cosmic gamma-ray burst (GRB) is thought to produce emission from two physical processes: the central engine gives rise to the high-energy emission of the burst through internal shocking, and the subsequent interaction of the flow with the external environment produces long-wavelength afterglows. Although observations of afterglows continue to refine our understanding of GRB progenitors and relativistic shocks, gamma-ray observations alone have not yielded a clear picture of the origin of the prompt emission nor details of the central engine. Only one concurrent visible-light transient has been found and it was associated with emission from an external shock. Here we report the discovery of infrared emission contemporaneous with a GRB, beginning 7.2 minutes after the onset of GRB 041219a (ref. 8). We acquired 21 images during the active phase of the burst, yielding early multi-colour observations. Our analysis of the initial infrared pulse suggests an origin consistent with internal shocks.     

Irreversible synthetische inhibitoren der Urokinase

Summary Urokinase, the plasminogen activator from urine, is inhibited irreversibly by diisopropyl fluorophosphate and 4-nitrobenzyl 4-guanidinobenzoate. The reactions of inhibition underlie pseudofirst-order kinetics. Rate constants were estimated. Urokinase is not inactivated by incubation with tosyl-l-lysine chloromethyl ketone.     

A powerful bursting radio source towards the Galactic Centre

Transient astronomical sources are typically powered by compact objects and usually signify highly explosive or dynamic events. Although high-time-resolution observations are often possible in radio astronomy, they are usually limited to quite narrow fields of view. The dynamic radio sky is therefore poorly sampled, in contrast to the situation in the X-ray and gamma-ray bands in which wide-field instruments routinely detect transient sources. Here we report a transient radio source, GCRT J1745-3009, which was detected during a moderately wide-field monitoring programme of the Galactic Centre region at 0.33 GHz. The characteristics of its bursts are unlike those known for any other class of radio transient. If located in or near the Galactic Centre, its brightness temperature (approximately 10(16) K) and the implied energy density within GCRT J1745-3009 vastly exceed those observed in most other classes of radio astronomical sources, and are consistent with coherent emission processes that are rarely observed. We conclude that it represents a hitherto unknown class of transient radio sources, the first of possibly many new classes that may be discovered by emerging wide-field radio telescopes.     

Der Einfluss von Papaverin auf Funktionen der Blutplättchen

Summary The adhesiveness and the ADP-induced aggregation of human blood platelets as well as the agglomeration and viscous metamorphosis initiated by thrombin was inhibited by papaverin. The release of biogenic amines and ATP from rabbit blood platelets induced by thrombin or other proteolytic enzymes was diminished. Also eupaverin and ethylpapaverin have an inhibitory effect on the platelet functions.