Compact pnCCD-based X-ray camera with high spatial and energy resolution: a color X-ray camera.

For many applications there is a requirement for nondestructive analytical investigation of the elemental distribution in a sample. With the improvement of X-ray optics and spectroscopic X-ray imagers, full field X-ray fluorescence (FF-XRF) methods are feasible. A new device for high-resolution X-ray imaging, an energy and spatial resolving X-ray camera, is presented. The basic idea behind this so-called "color X-ray camera" (CXC) is to combine an energy dispersive array detector for X-rays, in this case a pnCCD, with polycapillary optics. Imaging is achieved using multiframe recording of the energy and the point of impact of single photons. The camera was tested using a laboratory 30 µm microfocus X-ray tube and synchrotron radiation from BESSY II at the BAMline facility. These experiments demonstrate the suitability of the camera for X-ray fluorescence analytics. The camera simultaneously records 69,696 spectra with an energy resolution of 152 eV for manganese K(α) with a spatial resolution of 50 µm over an imaging area of 12.7 × 12.7 mm(2). It is sensitive to photons in the energy region between 3 and 40 keV, limited by a 50 µm beryllium window, and the sensitive thickness of 450 µm of the chip. Online preview of the sample is possible as the software updates the sums of the counts for certain energy channel ranges during the measurement and displays 2-D false-color maps as well as spectra of selected regions. The complete data cube of 264 × 264 spectra is saved for further qualitative and quantitative processing.

Atypical antipsychotic medication improves aggression, but not self-injurious behaviour, in adults with intellectual disabilities.

OBJECTIVE: Atypical antipsychotic medications have largely supplanted their typical counterparts, both for psychosis and for the treatment of aggression and/or self-injurious behaviour (SIB), in persons with intellectual disabilities (ID). However, with the exception of risperidone, little systematic research supports their use in such persons. METHOD: A retrospective review of 31 adult residents of a state developmental centre, who were treated for aggression and/or SIB with atypical antipsychotics. Average monthly counts of aggression and SIB for 1 year of treatment with typical antipsychotics, were compared with monthly averages for the next 12 months of treatment with atypical antipsychotics. RESULTS: Twenty-seven of 31 subjects (87%) completed a full year of atypical antipsychotic treatment. Subjects ranged in age from 24 to 54 years (mean = 39); 18/31 (58%) had profound ID. Twelve of 26 (46%) had typical antipsychotics discontinued within the year of atypical treatment; another 7/26 (27%) had their typical antipsychotic dose decreased. Twenty-three of 31 trials involved risperidone; 7/31 olanzapine; 1/31 quetiapine. Subjects gained an average of 6.6 pounds during the year of atypical treatment, but no significant changes in glucose or cholesterol were found. Subjects with aggression alone (N = 14) had significant decreases in the number of aggressive acts per month during the year of atypical treatment (P = 0.03); those with both aggression and self-injury (N = 12), or those with self-injury alone (N = 5) had no significant improvement. CONCLUSION: The findings suggest that atypical antipsychotics can be successfully substituted for typical agents in individuals with ID and decrease the frequency of aggression over one year of treatment. The weight gain seen in our sample reinforces the necessity of regular monitoring of weight and metabolic changes in persons with ID treated with atypical antipsychotics.

High spectral resolution x-ray optics with highly oriented pyrolytic graphite.

Thin films of highly oriented pyrolytic graphite (HOPG) give the opportunity to realize crystal optics with arbitrary geometry by mounting it on a mould of any shape. A specific feature of HOPG is its mosaicity accompanied by a high integral reflectivity, which is by an order of magnitude higher than that of all other known crystals in an energy range between 2 keV up to several 10 keV. These characteristics make it possible to realize highly efficient collecting optics, which could be also relevant for compact x-ray diagnostic tools and spectrometers. For these applications the achievable spectral resolution of the crystal optics is of interest. In this article measurements with a spectral resolution of E/DeltaE=2900 in the second order reflection and E/DeltaE=1800 in the first order reflection obtained with HOPG crystals are presented. These are by far the highest spectral resolutions reported for HOPG crystals. The integral reflectivity of these very thin films is still comparable with that of ideal Ge crystals. The trade-off between energy resolution and high integral reflectivity for HOPG is demonstrated by determining these parameters for HOPG films of different thickness.

High efficiency, high quality x-ray optic based on ellipsoidally bent highly oriented pyrolytic graphite crystal for ultrafast x-ray diffraction experiments.

By the use of a thin highly oriented pyrolytic graphite crystal (HOPG) bent to a high-performance ellipsoidal shape it was possible to focus monochromatic x-rays of 4.5 keV photon energy with an efficiency of 0.0033, which is 30 times larger than for previously used bent crystals. Isotropic Ti K alpha radiation of a 150 microm source was focused onto a 450 microm spot. The size of the focal spot can be explained by broadening due to the mosaic crystal rocking curve. The rocking curve width (FWHM) of the thin graphite foil was determined to 0.11 degrees. The estimated temporal broadening of an ultrashort K alpha pulse by the crystal is not larger than 300 fs. These properties make the x-ray optic very attractive for ultrafast time-resolved x-ray measurements.

Near monochromatic X-rays for digital slot-scan mammography: initial findings.

X-ray spectra are composed of a broad bremsspectrum and anode-characteristic emission lines. In mammography typically molybdenum (Mo), rhodium (Rh) or tungsten (W) anodes are used in combination with Mo, Rh or aluminium filters. Only the photons with energies between 17 and 22 keV of the resulting spectrum are suitable for the soft tissue imaging needed for mammography. The aim of this article is to present first results obtained with a monochromator module mounted at the exit of the X-ray tube of a conventional clinical mammography unit. The experimental setup consists of a Siemens Mammomat 300, an X-ray monochromator module and a linear array detector for image acquisition. The technique is similar to the slot-scan technique known from digital mammography. The experimental machine allows to obtain images both with polychromatic and monochromatic X-rays. Initial evaluation of the system was performed by examination of a contrast-detail phantom (CD-MAM-phantom, Nijmegen, The Netherlands). Images done with the new monochromatic technique were compared to images of the phantom done with polychromatic spectra, with film-screen mammography as well as with digital mammography. The new technique with monochromatic slot-scan mammography resulted in correct identification of 93% of the phantom. Digital slot-scan mammography with polychromatic beam resulted in correct identification of 87%, digital full-field mammography in 83% and conventional film-screen mammography in 70% of the phantom. The results suggest that monochromatization has a potential for improving image quality or decreasing dose in X-ray mammography.

Therapeutical effect of modified adamantane copolymer compounds: study of molecular mechanisms.

Copolymers of N-polyvinylpyrrolidone-acrylic acid (AB-1) and adamantane derivatives are known to possess marked antiviral activity in in vitro and in ovo models. Among the constructed preparations of AB-1 modified by adamantane derivatives some, especially AB-4 (modified by deitiforin), were found to show more extended antiviral activity and to inhibit markedly virus reproduction in susceptible permissive cell cultures and chicken embryos. In AB-4 treated cells and allantoic sacs, virus titers (influenza virus, herpes virus, and HIV) and virus antigen concentration were decreased. On the other hand, herpes virus-specific thymidine kinase and of DNA-polymerases isolated from Escherichia coli, Plectonema boryanum, and herpes virus type 1 infected murine brain tissue retained their activity after incubation with AB-4 or AB-2. The compounds investigated, in view of their effect on virus reproduction, are thought to be prospective as antiviral agents.

Study of immunotropic activities of Bacillus subtilis as the basis of anti-scleroma probiotics.

Presence of influence of Bacillus subtilis during peroral and parenteral administration upon the laboratory animals' immune system has been studied. Absence of immuno-depressing action of the bacillus culture under study has been presented with the help of assessment tests on the humoral response to the thymus-dependent antigen: creation of the antibodies, and the delayed-onset hypersensitivity reaction. An insignificant stimulating effect has been revealed under execution of the reaction of the delayed-onset hypersensitivity as a result of B. subtilis application. The obtained data confirm the prospects of application of the B. subtilis strain as a basis of the anti-scleroma probiotics.