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The energetic particle radiation environment on the International Space Station (ISS) includes both charged and neutral particles. Here, we make use of the unique capabilities of the Radiation Assessment Detector (ISS-RAD) to measure both of these components simultaneously. The Charged Particle Detector (CPD) is, despite its name, capable of measuring neutrons in the energy range from about 4 MeV to a few hundred MeV. Combined with data from the Fast Neutron Detector (FND) in the 0.2 to 8 MeV range, we present the first broad-spectrum measurements of the neutron environments in various locations within the ISS since an early Bonner-Ball experiment that was conducted before the Station was fully constructed. The data presented here span the time period from February 2016 to February 2022. In addition to presenting broad-spectrum neutron fluence measurements, we show correlations of the measured neutron dose equivalent with charged-particle dose rates. The ratio of charged-particle dose to neutron dose equivalent is found to be relatively stable within the ISS.

Dorschner et al [5–9] have described the unique function and form of several different muscle systems of the urinary bladder neck. If these systems have different functional responsibilities, then the muscles must undergo different ageing processes, as stated in the theory of function-dependent ageing. One characteristic of histologic ageing is the change over time in the proportion of muscle cells to connective tissue, a phenomenon we have demonstrated in both the ciliary muscle and in the two muscle systems of the small intestine [20]. Using an SIS-Image Analysing System, we have now measured automatically the ratios of muscle cells to connective tissue in sections from several regions of the urinary bladder neck, taken from 50 male and 15 female cadavers. Our results confirm new functional explanations of the different muscle systems in the bladder neck. The relative volume of muscle cells in both the sphincter trigonalis m. and the dilator urethrae m. diminishes continuously with age. In the ejaculatorius m., however, the volume of muscle cells first increases until beginning at the end of the third decade, it decreases until senescence. As was presumed, the proportion of muscle cells in the detrusor vesicae m. does not decline during the later decades. The volume of muscle cells and fibers in both urethral sphincter muscles, however, decreases with age, beginning in early childhood.

The biological activity of monoclonal antibodies specific for the hemagglutinin protein of measles virus strain CAM recognizing six epitope groups according to their binding properties to measles virus strain CAM/R401 was investigated in vivo in our rat model of measles encephalitis. When injected intraperitoneally into measles virus-infected suckling rats, some monoclonal antibodies modified the disease process and prevented the necrotizing encephalopathy seen in untreated animals. The analysis of measles virus brain isolates revealed emergence of variants that resisted neutralization with the passively transferred selecting monoclonal antibody but not with other monoclonal antibodies. Monoclonal antibody escape mutants were also isolated in vitro, and their neurovirulence varied in the animal model. Sequence data from the hemagglutinin gene of measles virus localize a major antigenic surface determinant of the hemagglutinin protein between amino acid residues 368 and 396, which may be functionally important for neurovirulence. The data indicate that the interaction of antibodies with the measles virus H protein plays an important role in the selection of neurovirulent variants. These variants have biological properties different from those of the parent CAM virus.

Computer simulations of the dissociation dynamics of argon and xenon neutral and singly charged clusters with 5 - 20 atoms were performed. It is shown that the stability of clusters with ‘magic numbers’ of atoms (n = 19 for argon, and n = 13,19 for xenon) as found in TOF mass spectra, is more enhanced by ionization than that of their neighbours, indicating the importance of the ionization for the cluster size distribution found in experiments.

Homogeneous irradiation of amorphous materials with a high energy heavy ion-beam results in visible growth of the sample dimensions perpendicular to and shrinkage of the sample dimension parallel to the ion beam. The quantitative details of this effect are remarkably similar although the investigated materials belong to completely different classes of amorphous solids. A simple relation is derived which explains this universal behavior.

A great number of different carbon particles with a supposedly closed-shell structure such as C60have have detected in sooting flames. Mass spectra of positive and negative ions of this kind (called polyhedral carbon ions) are presented for low-pressure acetylene- and benzene-oxygen flames. By the use of C6D6it could be confirmed that the particles with an even number of C atoms in fact do not contain hydrogen. Those with an odd number are much less abundant and carry 1 or 2 H atoms. The mass distributions of positive and negative polyhedral ions are quite different, the negative having more and larger particles. Concentration profiles of ions of both signs are reported, and the influence of the C/O ratio and the unburned gas velocity is investigated. The mechanism of formation of these particles is discussed. Arguments are presented that support the working hypothesis that the polyhedral carbon particles are formed from small soot particles rather than by a direct building-up from smaller molecular species.

The dopaminergic system is a candidate neurotransmitter system thought to be involved in the pathogenesis of depression. This study addresses the issue whether the antidepressant efficacy of serotonin reuptake inhibition is related to changes in the cerebral dopaminergic system. Cerebral dopamine-D2receptors were characterized in 13 patients with major depression using the dopamine-D2receptor antagonist iodobenzamide and single photon emission tomography. Dopamine receptor binding was assessed twice, before and during serotonin reuptake inhibition. An increase in dopamine-D2receptor binding during serotonin reuptake inhibition was found in striatum and anterior cingulate gyrus in treatment responders, but not in nonresponders. The increase in dopamine-D2receptor binding correlated significantly with clinical recovery from depression as assessed with the Hamilton depression scale (r=0.59 for right and left striatum respectively,P<0.05;r=0.79 for the anterior cingulate gyrus,P<0.05 after Bonferroni correction). Qualitatively similar correlations were observed in the precentral gyrus, the medial frontal gyrus, the inferior frontal gyrus, and the frontal part of the opercular gyrus, but these correlations failed to reach statistical significance after correction for the effects of multiple testing. No such correlations were found in the superior frontal gyrus, the orbitofrontal gyrus, the gyrus rectus, the superior parietal gyrus, or the superior temporal gyrus. The data strengthen the concept that the striatum and the anterior cingulate gyrus are involved in mood regulation. Dopamine-D2receptors may constitute a central role in this domain.

The expression of measles virus (MV) in six different permanent human glioma cell lines (D-54, U-251, U-138, U-105, U-373, and D-32) was analyzed. Although all cell lines were permissive for productive replication of all MV strains tested, U-251, D-54, and D-32 cells spontaneously revealed restrictions of MV transcription similar to those observed for primary rat astroglial cells and brain tissue. In vitro differentiation of D-54 and U-251 cells by substances affecting the intracellular cyclic AMP level caused a significant reduction of the expression of the viral proteins after 18, 72, and 144 h of infection. This pronounced restriction was not paralleled to a comparable level by an inhibition of the synthesis and biological activity in vitro of virus-specific mRNAs as shown by quantitative Northern (RNA) blot analyses and in vitro translation. The block in viral protein synthesis could not be attributed to the induction of type I interferon by any of the substances tested. Our findings indicate that down-regulation of MV gene expression in human brain cells can occur by a cell type-dependent regulation of the viral mRNA transcription and a differentiation-dependent regulation of translation, both of which may be crucial for the establishment of persistent MV infections in the central nervous system.

Canine distemper virus (CDV), a lymphotropic and neurotropic negative-stranded RNA virus of the Morbillivirus genus, causes a life-threatening disease in several carnivores, including domestic dogs. To identify the cellular receptor(s) involved in the uptake of CDV by susceptible cells, we isolated a monoclonal antibody (MAb K41) which binds to the cell surface and inhibits the CDV infection of several cell lines from various species. Pretreatment of cells with MAb K41 reduces the number of infectious centers and the size of the syncytia. Using affinity chromatography with MAb K41, we purified from HeLa and Vero cell extracts a 26-kDa protein which contained the amino acid sequence TKDEPQRETLK of human CD9, a member of the tetraspan transmembrane or transmembrane 4 superfamily of cell surface proteins. Transfection of NIH 3T3 or MDBK cells with a CD9 expression plasmid rendered these cells permissive for viral infection and raised virus production by a factor of 10 to 100. The mechanism involved is still unclear, since we were unable to detect direct binding of CDV to CD9 by using immunoprecipitation and a virus overlay protein binding assay. These findings indicate that human CD9 and its homologs in other species are necessary factors for the uptake of CDV by target cells, the formation of syncytia, and the production of progeny virus.

The removal of well-fixed acetabular components following total hip arthroplasty (THA) is a difficult operation and could be accompanied by the loss of acetabular bone stock. The optimal method for fixation is still under debate. The aim of this pilot study was to compare the tear-out resistance and failure behavior between osseo-integrated and non-integrated screw cups. Furthermore, we examined examined whether there are differences in the properties mentioned between screw sockets and cemented polyethylene cups.