Fast FMCW Terahertz Imaging for In-Process Defect Detection in Press Sleeves for the Paper Industry and Image Evaluation with a Machine Learning Approach.

We present a rotational terahertz imaging system for inline nondestructive testing (NDT) of press sleeves for the paper industry during fabrication. Press sleeves often consist of polyurethane (PU) which is deposited by rotational molding on metal barrels and its outer surface mechanically processed in several milling steps afterwards. Due to a stabilizing polyester fiber mesh inlay, small defects can form on the sleeve's backside already during the initial molding, however, they cannot be visually inspected until the whole production processes is completed. We have developed a fast-scanning frequenc-modulated continuous wave (FMCW) terahertz imaging system, which can be integrated into the manufacturing process to yield high resolution images of the press sleeves and therefore can help to visualize hidden structural defects at an early stage of fabrication. This can save valuable time and resources during the production process. Our terahertz system can record images at 0.3 and 0.5 THz and we achieve data acquisition rates of at least 20 kHz, exploiting the fast rotational speed of the barrels during production to yield sub-millimeter image resolution. The potential of automated defect recognition by a simple machine learning approach for anomaly detection is also demonstrated and discussed.

[Illness and death of the violin virtuoso Nicolò Paganini--interpretation based on new hair investigations]. / Krankheit und Tod des Violin-Virtuosen Nicolò Paganini--Interpretation auf Basis neuer Haaruntersuchungen.

The violin virtuoso Paganini died at Nice in 1840 after a long, severe illness. It is undisputed that Paganini was treated with mercury for suspected syphilis and lost all his teeth in 1828 because of that treatment. In the comprehensive literature published on this topic, most authors assume that the terminal complaints and his death were caused by tuberculosis. On the other hand, the hypothesis that he may have died from mercury poisoning was rejected, because there was no information available supporting this assumption. The authors performed morphological investigations using light microscopy and raster electron microscopy (REM). The examined hairs corresponded to a growth phase of > 1 year and < 3 years before death. Structural damage to the hairs indicate heavy metal intoxication in that phase of life; compatible results were supplied by the complex investigations using ICP mass spectrometry and TXRF, which revealed high concentrations of mercury. Using ICP-MS, the mean value for mercury found in the hair sample was 15.4 microg/g with a standard deviation of 0.7 microg/g. The values obtained when investigating segments of single hairs showed high dispersion, but overlapped with the values from the area investigated using ICP-MS. Information not yet considered in the literature support the diagnosis of syphilis and provide a complete and unambiguous explanation for Paganini's death on the basis of the mercury concentrations found.

Volatile organic compounds in dwelling houses and stables of dairy and cattle farms in Northern Germany.

Farmers are exposed to a complex mixture of airborne substances which can represent a health hazard. Especially animal production on a farm can be a risk factor for respiratory diseases. Most studies in this context focused on bioaerosols, compounds attached to bioaerosols or on gases such as ammonia or hydrogen sulfide. Less attention was paid to volatile organic compounds (VOCs) which may also cause respiratory diseases. This pilot study presents results of measuring VOCs in the air of the dwellings and stables, as well as in the outdoor environment, of cattle farms in Northern Germany in spring and autumn. Farmers on all selected farms complained of symptoms such as asthma, rhinitis and conjunctivitis which occurred especially during work in the stable but also in the dwellings. The mean concentration of total VOC (TVOC) for the outdoor environment, the dwellings, and the stables were 100 microg m(-3), 763 microg m(-3), 322 microg m(-3) in spring and 143 microg m(-3), 544 microg m(-3), 595 microg m(-3) in autumn, respectively. There was no significant difference in season. TVOC concentrations in dwellings on farms were elevated when compared to dwellings in other environments, probably because of an additional exposure to fuels and chemicals used in agriculture. Aliphatic and alicyclic hydrocarbons, aromatic compounds, and terpenes were main compounds of the dwellings and ketones, alcohols, and esters of the stables. Terpene concentrations in the stables were low probably because straw, which was not a strong terpene emitter, was used instead of sawdust as floor covering. Large amounts of methylethylketone were encountered in the air of one stable, probably from animal exhalation caused by increased animal activity. However, it was unlikely that this caused respiratory symptoms. Generally it was likely that the concentrations of VOCs were too low to have health effects on their own. On the other hand, the VOC concentrations were in a multifactor concentration range in which health effects could occur depending on the interaction with other exposure factors. Fungal spores and bacteria were observed in addition to VOCs at the examined locations. Therefore it is possible that the observed VOCs played a role in exacerbating respiratory symptoms in this multifactor exposure.

DNA damage in leukocytes of workers occupationally exposed to arsenic in copper smelters.

Inorganic arsenic (i-As) is a known human carcinogen; however, humans continue to be exposed to i-As in drinking water and in certain occupational settings. In this study, we used the Comet assay to evaluate DNA damage in the somatic cells of workers from three Polish copper smelters who were occupationally exposed to i-As. Blood samples were collected from 72 male workers and 83 unexposed male controls and used for the detection of DNA damage, oxidative DNA damage, and DNA damage after a 3-hr incubation in culture. Urine samples were collected to assess the level of exposure. The mean concentration of arsenic metabolites in urine [the sum of arsenite (AsIII), arsenate (AsV), monomethylarsenate (MMA) and dimethylarsenate (DMA)] and the concentrations of DMA (the main metabolite in urine) were higher in workers than in controls, but the differences were not statistically significant. By contrast, the level of DNA damage, expressed as the median tail moment, was significantly higher in the leukocytes of workers than in the controls. Comet assays conducted with formamidopyrimidine glycosylase (FPG) digestion to detect oxidative DNA damage indicated that oxidative lesions were present in leukocytes from both the exposed and control groups, but the levels of damage were significantly higher among the workers. Incubation of the cells in culture resulted in a significant reduction in the levels of DNA damage, especially among leukocytes from the workers, suggesting that the DNA damage was subject to repair. Our findings indicate that copper smelter workers have increased levels of DNA damage in somatic cells, suggesting a potential health risk for the workers. Although i-As was present in air samples from the smelters and in urine samples from workers, no clear association could be made between i-As exposure and the DNA damage.