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Patients who had experienced well-documented neurotoxic exposure months or years earlier were evaluated. Seventy-two right-handed adults who claimed continuing abnormalities of cognitive and memory function were examined after Xenon-133 inhalation and i.v. HMPAO. Single photon emission computed tomography (SPECT) results were statistically compared with age-matched controls. Bilateral, often asymmetrical, impairment of perfusion was found, mostly in the frontal, temporal, and parietal lobes. This hypoperfusion was predominantly left-sided in young patients and predominantly right-sided in the elderly. Abnormalities were found months and years after neurotoxic exposure had ceased. Our findings suggest that NeuroSPECT can provide evidence of impaired cerebral function and may therefore help to further define neurotoxic exposure and its chronic effects.  相似文献   
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Ohne ZusammenfassungMitteilung aus dem Nahrungsmittel-Untersuchungsamte der Stadt Oberhausen.  相似文献   
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Weld metal as strong as base metal? The development of new steels is always a challenge for the manufacturer of filler metals. In many cases it is obvious that some properties of the base metal cannot be fulfilled with matching filler metals. In some cases, dissimilar filler metals can solve the problem in some cases, there is no chance to meet the requirements of the base metal (for example yield strengths of new ultra high strength steels). This paper deals with different kinds of new steels and the requirements for the weld metal with examples from motor car industry (Mangan Austenite), crane (Ultra high strength steels), earthmoving machinery (Wear‐resistant steels) and offshore (Supermartensitic steels). Specific problems will be discussed and best solutions will be highlighted. These examples make clear that the success of new kinds of steels in the market depends on solving the joining problems of these steels.  相似文献   
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Washing of Disperse Solid Systems – Existing Washing Processes and Guidelines for Choosing the Appropriate Washing Procedure Washing of disperse solid systems is a widely used and complex operation. Since the washing‐step is mostly integrated into other process operations, it is subject to numerous demands, which exceed the primary demands like a good separation result and a low specific wash liquid demand. Because of the phenomenology and limits of different washing procedures it is difficult to choose an appropriate washing process. Additionally, the acting transport mechanisms of some washing procedures are not yet sufficiently understood. This work shows a broad overview over the existing washing processes, the numerous parameters and the demands they have to fulfill. A categorization of washing procedures as well as a classification of the processes concerning their macroscopic transport phenomena are the base for a broad decision chart which compares and evaluates existing washing processes and shows their individual limits. The work can be seen as a rough guideline for choosing the appropriate washing procedure.  相似文献   
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