Einsatz tomographischer Meßverfahren für verfahrenstechnische Untersuchungen

Use of tomographic measuring techniques for process engineering studies . Tomographic measuring techniques have so far been employed almost exclusively in medicine and for testing of materials. They permit determination of experimental values for all local coordinates of a given volume at a given time. Classical tomography can be used for measurements only in stationary fields of flow, temperature, and concentration since the object has to be irradiated from as many directions as possible during a finite time interval. In the case of transient events, however, it is necessary to acquire all these values at the same point in time. If transparent fluids are present then coherent light is suitable for irradiation and holographic interferometry for recording the measured values. Since irradiation must take place simultaneously from several directions, the number of recording angles should be kept to a minimum. It is also necessary to employ mathematical procedures for image reconstruction in order to ensure adequate accuracy of the measured values.     

Alternative medicine in private personal insurance

In Germany there is a trend to so-called "natural" or "alternative" medical methods especially among young people of good education and higher income. Those persons are also the typical target group of the private person insurance so that it seems necessary to deal with such methods. While the original "classical" methods of naturopathy have been acknowledged in the scientific medicine for many years and are mainly used in the medical rehabilitation, the so-called "alternative" methods are further on controversial. In the first place, the risks of such unconventional methods are to be monitored, especially the danger of a wrong diagnosis in using unproved diagnostical methods and the danger of side-effects in therapy. Another problematical fact is that during an unconventional treatment the diagnosis of an intoxication by outdoor or indoor pollution or by amalgam of toothfillings is often made without standing a critical proof. Usually, an expensive therapy will follow with no end in sight. Furthermore, the diagnosis of a so-called intoxication of psychical disordered patients, especially those with a masked depression, can prevent a necessary medical or psychotherapeutic treatment. Disorders will be felt more and more as somatic and get a chronical course so that they are finally resistant to therapy.     

An evaluation of nanostructured zinc oxide as a fluorescent powder for fingerprint detection

Zinc oxide is evaluated as a fluorescent powder for the detection of fingermarks on non-porous surfaces. Pure and lithium-doped nanostructured zinc oxide powders were characterized using scanning electron microscopy, X-ray diffraction, and fluorescence spectroscopy. The zinc oxide powders were applied to fresh and aged fingermarks deposited on non-porous surfaces such as glass, polyethylene and aluminium foil. Zinc oxide was found to produce clear fluorescent impressions of the latent fingermarks when illuminated with long-wave UV light. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Generation of NiTi Nanoparticles by Femtosecond Laser Ablation in Liquid

NiTi was investigated as a model system for a binary alloy where the properties strongly depend on the relative proportion of the two elements and on the grain size. The NiTi nanoparticles were generated by laser ablation in water. For the analysis of the particle size distribution, we used transmission electron microscopy and dynamic light scattering. Here, we found a broad particle size distribution (10-200 nm). Furthermore, the temperature-resolved x-ray powder diffraction and differential scanning calorimetry (DSC) were used to evaluate the phase transition behavior of the generated NiTi nanoparticles. Here, we found an interesting effect. During the heating by DSC, an austenite phase transition and a weak martensite phase transition in the NiTi nanoparticles appeared. Moreover, the phase transformation temperature was about 40 K lower than that of the bulk target.     

防水卷材屋面的机械式紧固

0 引言 卷材防水屋面(又称平屋面、大屋面)已在现代建筑行业得到广泛应用. 在产业化的背景下,此类构造的屋面防水形式已经可以很经济地实现,在各大洲均有数以百万计m2的屋面以此类构造建造.     

DNA ploidy and cell cycle distribution of breast cancer aspiratecells measured by image cytometry and analyzed by artificial neuralnetworks for their prognostic significance

Chromosomal abnormalities are commonly associated with cancer, and their importance in the pathogenesis of the disease has been well recognized. Also recognized in recent years is the possibility that, together with chromosomal abnormalities, DNA ploidy of breast cancer aspirate cells, measured by image cytometric techniques, may correlate with prognosis of the disease. Here, we have examined the use of an artificial neural network to predict: 1) subclinical metastatic disease in the regional lymph nodes and 2) histological assessment, through the analysis of data obtained by image cytometric techniques of fine needle aspirates of breast tumors. The cellular features considered were: 1) DNA ploidy measured in terms of nuclear DNA content as well as by cell cycle distribution; 2) size of the S-phase fraction; and 3) nuclear pleomorphism. A further objective of the study was to analyze individual markers in terms of impact significance on predicting outcome in both cases. DNA ploidy, indicated by cell cycle distribution, was found markedly to influence the prediction of nodal spread of breast cancer, and nuclear pleomorphism to a lesser degree. Furthermore, a comparison between histological assessment and artificial neural network prediction shows a closer correlation between the neural approach and the development of further metastases as indicated in subsequent follow-up, than does histological assessment     

Case Study of Steady Oxygen Concentration Gradients in a Groundwater Plume from a Highway Infiltration Basin

We measure and model the steady transport of specific conductivity and dissolved oxygen through a groundwater plume from a highway infiltration basin in southeastern Massachusetts. Specific conductivity is treated as a conservative surrogate for runoff contamination, and the data calibrate a 0.27-m vertical dispersivity α of the aquifer and the bottom streamline elevation of the plume, which falls to an 8-m depth below the water table. The dissolved oxygen degrades as a first order reactant in the plume to levels below 1 mg/L, with a decay constant λ of 0.12?day?1. The latter may be attributed in part to the historical use of an alternative de-icing agent calcium magnesium acetate on the highway, since acetate is a readily biodegradable substrate for microorganisms. The calibrated kinetics suggest that plume microbes and geochemistry degrade oxygen over two orders of magnitude faster than their ambient groundwater counterparts, which impose a linear decrease of dissolved oxygen concentration below the plume. Simulations suggest that the anoxic groundwater plume extends 1,600 m downgradient of the infiltration basin, a distance that will shorten by an order of magnitude if salt is used exclusively to de-ice the highway.     

Prevention of postoperative thrombotic stroke after carotid endarterectomy: the role of transcranial Doppler ultrasound

PURPOSE: To determine the incidence of particulate embolization after carotid endarterectomy (CEA), the effect of dextran-40 infusion in patients with sustained postoperative embolization, and the impact of transcranial Doppler (TCD) monitoring plus adjuvant dextran therapy on the rate of postoperative carotid thrombosis. METHODS: Prospective study in 100 patients who underwent CEA with 6-hour postoperative monitoring using a TCD that was modified to allow automatic, intermittent recording from the ipsilateral middle cerebral artery waveform (10 minute sample every 30 minutes). An incremental dextran-40 infusion was commenced if 25 or more emboli were detected in any 10-minute period. RESULTS: Overall, 48% of patients had one or more emboli detected in the postoperative period, particularly in the first 2 hours. However, sustained embolization that required Dextran therapy developed in only five patients. In each case, the rate of embolization rapidly diminished. CONCLUSIONS: A small proportion of patients have sustained embolization after CEA, which in previous studies has been shown to be highly predictive of thrombotic stroke. Intervention with dextran reduced and subsequently stopped all the emboli in those in whom it was used and contributed to a 0% perioperative morbidity and mortality rate in this series.     

Neighbourhood effects and social mobility: a longitudinal analysis

What impact do neighbourhoods have on social mobility? For years, this question has received widespread international attention in scholarly debates and within society at large. This paper seeks to contribute to this discussion by presenting the results of an investigation into the relationship between household social mobility and the composition of the residential environment. The analyses are based on an extensive empirical longitudinal study conducted in the Netherlands. The most remarkable conclusion is that, in the Dutch context, the environment has only a modest influence on the social mobility of households with a weak economic position. It was found that the chance of a household living purely on welfare benefits at the beginning of the study period to escape the ‘welfare trap’ was barely dependent on the number of similarly challenged households in the immediate vicinity. Interestingly, the environment proved to have a more powerful effect on the social mobility of households with a stronger economic position. The probability that households with at least one paid job at the beginning of the research would still have a job at the end clearly decreases as the share of benefit-dependent households in the neighbourhood rises. A possible explanation for this is that for the first category (weak starting position) the negative effect of their own welfare situation is far more determinative for their future prospects than the compo sition of their environment. Because these negative individualistic conditions are absent for the second category (stronger starting position), environmental factors may play a relatively larger role. Another interpretation is that area-based policies are not just targeting the areas with bigger problems more intensively, but especially the long-term unemployed in these areas, and not so much the short-term unemployed (those who had a job at the start of the research period and lost the job afterwards).     

A Novel Method Facilitating the Simple and Low-Cost Preparation of Human Osteochondral Slice Explants for Large-Scale Native Tissue Analysis

For in vitro modeling of human joints, osteochondral explants represent an acceptable compromise between conventional cell culture and animal models. However, the scarcity of native human joint tissue poses a challenge for experiments requiring high numbers of samples and makes the method rather unsuitable for toxicity analyses and dosing studies. To scale their application, we developed a novel method that allows the preparation of up to 100 explant cultures from a single human sample with a simple setup. Explants were cultured for 21 days, stimulated with TNF-α or TGF-β3, and analyzed for cell viability, gene expression and histological changes. Tissue cell viability remained stable at >90% for three weeks. Proteoglycan levels and gene expression of COL2A1, ACAN and COMP were maintained for 14 days before decreasing. TNF-α and TGF-β3 caused dose-dependent changes in cartilage marker gene expression as early as 7 days. Histologically, cultures under TNF-α stimulation showed a 32% reduction in proteoglycans, detachment of collagen fibers and cell swelling after 7 days. In conclusion, thin osteochondral slice cultures behaved analogously to conventional punch explants despite cell stress exerted during fabrication. In pharmacological testing, both the shorter diffusion distance and the lack of need for serum in the culture suggest a positive effect on sensitivity. The ease of fabrication and the scalability of the sample number make this manufacturing method a promising platform for large-scale preclinical testing in joint research.