A heterodyne interferometer with separated beam paths for high-precision displacement and angular measurements

As standard concepts for precision positioning within a machine reach their limits with increasing measurement volumes, inverse concepts are a promising approach for addressing this problem. The inverse principle entails other limitations, as for high-precision positioning of a sensor head within a large measurement volume, three four-beam interferometers are required in order to measure all necessary translations and rotations of the sensor head and reconstruct the topography of the reference system consisting of fixed mirrors in the x-, y-, and z-directions. We present the principle of a passive heterodyne laser interferometer with consequently separated beam paths for the individual heterodyne frequencies. The beam path design is illustrated and described, as well as the design of the signal-processing and evaluation algorithm, which is implemented using a System-On-a-Chip with an integrated FPGA, CPU, and A/D converters. A streamlined bench-top optical assembly was set up and measurements were carried out to investigate the remaining non-linearities. Additionally, reference measurements with a commercial homodyne interferometer were executed

Heterodynes Interferometer mit vier Strahlen für hochpräzise Längen- und Winkel-messung in Nanopositionier- und Nanomessmaschinen

Um gestiegenen Anforderungen an das Messvolumen von Nanopositionier- und Nanomessmaschinen Rechnung zu tragen, wurde ein neues inverses Konzept entwickelt. Für die hochpräzise Positionierung des Sensorkopfs im Messraum werden dabei vier interferometrische Messachsen für jede Raumrichtung benötigt. Es wird ein Heterodyn-Laserinterferometer für diese Aufgabe vorgestellt sowie Messergebnisse präsentiert

Особенности упрочнения и разрушения аустенитной стали в условиях разных схем воздействия мегавольтного электронного луча

В данной исследовательской работе были исследованы образцы 304L после ударно-волнового нагружения сильноточным наносекундным релятивистским электронным пучком.. Целью данной работы является исследование влияния многократного динамического нагружения образцов стали 304L при изменении схемы воздействия на эволюцию структуры материала по объему мишени. С бурным развитием авиакосмической техники и современного высокоскоростного воздействия на материалы к ним предъявляются жесткие требования по комплексу физико-механических свойств. Однако в реальных условиях эксплуатации такому воздействию материал может подвергаться неоднократно, меняя схему нагружения. Это в частности касается воздействия УВ как с фронтальной, так и с тыльной части мишени.In this research work, 304L samples were studied after shock-wave loading by a high-current nanosecond relativistic electron beam .. The aim of this work is to study the effect of multiple dynamic loading of 304L steel samples when changing the pattern of influence on the evolution of the material structure over the target volume. With the rapid development of aerospace engineering and modern high-speed impact on materials, stringent requirements are imposed on them for a set of physical and mechanical properties. However, under real operating conditions, the material can be exposed to this effect repeatedly, changing the loading scheme. This is particularly true for the impact of hydrocarbons from both the front and the back of the target

Detection of pneumonia associated pathogens using a prototype multiplexed pneumonia test in hospitalized patients with severe pneumonia

Severe pneumonia remains an important cause of morbidity and mortality. Polymerase chain reaction (PCR) has been shown to be more sensitive than current standard microbiological methods--particularly in patients with prior antibiotic treatment--and therefore, may improve the accuracy of microbiological diagnosis for hospitalized patients with pneumonia. Conventional detection techniques and multiplex PCR for 14 typical bacterial pneumonia-associated pathogens were performed on respiratory samples collected from adult hospitalized patients enrolled in a prospective multi-center study. Patients were enrolled from March until September 2012. A total of 739 fresh, native samples were eligible for analysis, of which 75 were sputa, 421 aspirates, and 234 bronchial lavages. 276 pathogens were detected by microbiology for which a valid PCR result was generated (positive or negative detection result by Curetis prototype system). Among these, 120 were identified by the prototype assay, 50 pathogens were not detected. Overall performance of the prototype for pathogen identification was 70.6% sensitivity (95% confidence interval (CI) lower bound: 63.3%, upper bound: 76.9%) and 95.2% specificity (95% CI lower bound: 94.6%, upper bound: 95.7%). Based on the study results, device cut-off settings were adjusted for future series production. The overall performance with the settings of the CE series production devices was 78.7% sensitivity (95% CI lower bound: 72.1%) and 96.6% specificity (95% CI lower bound: 96.1%). Time to result was 5.2 hours (median) for the prototype test and 43.5 h for standard-of-care. The Pneumonia Application provides a rapid and moderately sensitive assay for the detection of pneumonia-causing pathogens with minimal hands-on time

Comparison of commercial DNA preparation kits for the detection of Brucellae in tissue using quantitative real-time PCR

<p>Abstract</p> <p>Background</p> <p>The detection of Brucellae in tissue specimens using PCR assays is difficult because the amount of bacteria is usually low. Therefore, optimised DNA extraction methods are critical. The aim of this study was to assess the performance of commercial kits for the extraction of <it>Brucella </it>DNA.</p> <p>Methods</p> <p>Five kits were evaluated using clinical specimens: QIAamp™ DNA Mini Kit (QIAGEN), peqGold™ Tissue DNA Mini Kit (PeqLab), UltraClean™ Tissue and Cells DNA Isolation Kit (MoBio), DNA Isolation Kit for Cells and Tissues (Roche), and NucleoSpin™ Tissue (Macherey-Nagel). DNA yield was determined using a quantitative real-time PCR assay targeting IS<it>711 </it>that included an internal amplification control.</p> <p>Results</p> <p>Kits of QIAGEN and Roche provided the highest amount of DNA, Macherey-Nagel and Peqlab products were intermediate whereas MoBio yielded the lowest amount of DNA. Differences were significant (p < 0.05) and of diagnostic relevance. Sample volume, elution volume, and processing time were also compared.</p> <p>Conclusions</p> <p>We observed differences in DNA yield as high as two orders of magnitude for some samples between the best and the worst DNA extraction kits and inhibition was observed occasionally. This indicates that DNA purification may be more relevant than expected when the amount of DNA in tissue is very low.</p

Comparison of Eleven Commercial Tests for Chlamydia pneumoniae-Specific Immunoglobulin G in Asymptomatic Healthy Individuals

The seroprevalence of anti-Chlamydia pneumoniae-specific immunoglobulin G (IgG) antibodies is high in the adult population. Experience is required to perform a microimmunofluorescence test (MIF), the current “gold standard” for serological diagnosis, and the assay still lacks standardization. Partially automated enzyme-linked immunosorbent assays (ELISAs) and enzyme immunoassays (EIAs), which are more standardized and for which the reading of results is less subjective, have been developed. The different commercially available serological tests differ in their sensitivities and specificities, depending primarily on the antigen used. Therefore, we evaluated 11 different tests (10 were species specific, 1 was genus specific) for IgG antibodies using serum samples of 80 apparently healthy volunteers. The interpretation of the results was based on the results of the gold standard, MIF: a sample was judged positive if it was positive by at least three of the four different MIFs. Based on this internal standard, we found that 71% of the samples were positive, while 8% were false positive by some tests. The correlations between the results of the different MIFs ranged from 83 to 99%, and the correlations between the results of the MIFs and the different ELISAs and EIAs ranged from 78 to 98%. Comparison of the IgG titers measured by MIF showed good agreement (r = 0.76 to 0.91). This analysis revealed that some ELISAs and EIAs fail to detect low IgG titers. The specificities of the species-specific tests varied from 95 to 100%, and the sensitivities varied from 58 to 100%. These results indicate that serological assays for the detection of anti-C. pneumoniae-specific IgG vary greatly in their sensitivities and specificities. MIF must still be considered the best method for the detection of IgG in apparently healthy subjects, but the sensitivities and specificities of new ELISAs approximate those of MIFs

Host Cell Cytokines Induced by Chlamydia pneumoniae Decrease the Expression of Interstitial Collagens and Fibronectin in Fibroblasts▿

Chlamydia pneumoniae infection has been associated with chronic obstructive airway disease (COPD), asthma, and atherosclerosis. Inflammation and airway remodeling in asthma and COPD result in subepithelial fibrosis that is characterized by the deposition of interstitial collagens and fibronectin. The progression of atherosclerosis is also accompanied by an increased production of interstitial collagens in the intima. As shown by reverse transcription-PCR and immunoblotting, infection of human fibroblasts and smooth muscle cells by C. pneumoniae TW-183 downregulated the expression of type I and III collagen and fibronectin, whereas the level of type IV collagen remained unchanged. Conditioned medium from infected fibroblasts as well as epithelial WISH cells also reduced the expression of interstitial collagens and fibronectin in uninfected cells. In experiments using blocking antibodies, beta interferon was found to contribute to the inhibitory effects of conditioned medium collected from infected fibroblasts. In contrast, downregulation of matrix protein expression by conditioned medium from epithelial cells was caused by interleukin-1α, which was not secreted from fibroblasts following chlamydial infection. C. pneumoniae-mediated inhibition of collagen and fibronectin expression was diminished following transfection of fibroblasts with specific small interfering RNA targeting the transcription factor CCAAT/enhancer-binding protein β. The downregulation of interstitial collagens and fibronectin by the Chlamydia-induced host cell cytokine response may modulate tissue remodeling processes in airway diseases. In atherosclerosis the inhibition of collagen synthesis by C. pneumoniae infection may promote plaque vulnerability, thereby increasing the risk of plaque rupture

BCG strain S4-Jena: An early BCG strain is capable to reduce the proliferation of bladder cancer cells by induction of apoptosis

<p>Abstract</p> <p>Background</p> <p>Intravesical immunotherapy with <it>Mycobacterium bovis </it>bacillus Calmette-Guérin has been established as the most effective adjuvant treatment for high risk non-muscle-invasive bladder cancer (NMIBC). We investigated the differences between the S4-Jena BCG strain and commercially available BCG strains. We tested the genotypic varieties between S4-Jena and other BCG strains and analysed the effect of the BCG strains TICE and S4-Jena on two bladder cancer cell lines.</p> <p>Results</p> <p>In contrast to commercially available BCG strains the S4-Jena strain shows genotypic differences. Spoligotyping verifies the S4-Jena strain as a BCG strain. Infection with viable S4-Jena or TICE decreased proliferation in the T24 cell line. Additionally, hallmarks of apoptosis were detectable. In contrast, Cal29 cells showed only a slightly decreased proliferation with TICE. Cal29 cells infected with S4-Jena, though, showed a significantly decreased proliferation in contrast to TICE. Concordantly with these results, infection with TICE had no effect on the morphology and hallmarks of apoptosis of Cal29 cells. However, S4-Jena strain led to clearly visible morphological changes and caspases 3/7 activation and PS flip.</p> <p>Conclusions</p> <p>S4-Jena strain has a direct influence on bladder cancer cell lines as shown by inhibition of cell proliferation and induction of apoptosis. The data implicate that the T24 cells are responder for S4-Jena and TICE BCG. However, the Cal29 cells are only responder for S4-Jena and they are non-responder for TICE BCG. S4-Jena strain may represent an effective therapeutic agent for NMIBC.</p