Enhanced biological carbon consumption in a high CO2 ocean.

The oceans have absorbed nearly half of the fossil-fuel carbon dioxide (CO2) emitted into the atmosphere since pre-industrial times, causing a measurable reduction in seawater pH and carbonate saturation. If CO2 emissions continue to rise at current rates, upper-ocean pH will decrease to levels lower than have existed for tens of millions of years and, critically, at a rate of change 100 times greater than at any time over this period. Recent studies have shown effects of ocean acidification on a variety of marine life forms, in particular calcifying organisms. Consequences at the community to ecosystem level, in contrast, are largely unknown. Here we show that dissolved inorganic carbon consumption of a natural plankton community maintained in mesocosm enclosures at initial CO2 partial pressures of 350, 700 and 1,050 microatm increases with rising CO2. The community consumed up to 39% more dissolved inorganic carbon at increased CO2 partial pressures compared to present levels, whereas nutrient uptake remained the same. The stoichiometry of carbon to nitrogen drawdown increased from 6.0 at low CO2 to 8.0 at high CO2, thus exceeding the Redfield carbon:nitrogen ratio of 6.6 in today's ocean. This excess carbon consumption was associated with higher loss of organic carbon from the upper layer of the stratified mesocosms. If applicable to the natural environment, the observed responses have implications for a variety of marine biological and biogeochemical processes, and underscore the importance of biologically driven feedbacks in the ocean to global change.

[Variation in X-ray dose quantity using an amorphous selenium based flat-panel detector -- a study on the dose reduction rate up to the limit of diagnostical utilization]. / Dosisvariation mit einem direkten Selen-Flachbilddetektor -- Eine Studie zur Dosisreduktion bis an die Grenzen der diagnostischen Verwertbarkeit.

PURPOSE: To evaluate the diagnostic quality and minimum required dose to obtain acceptable images for diagnostic purposes in the field of musculoskeletal radiology. MATERIALS AND METHODS: A critical comparison of the image quality produced by a novel flat panel detector and the conventional screen/film system using a contrast-detail phantom was performed in phase I. Images from both systems were obtained with the same dose and displayed with similar contrast and density. In phase II images of significant anatomical structures in cadaver extremities obtained using the digital detector system and the standard film/screen system were critically evaluated. After a successive reduction in the X-ray dose for 84 patients in phase III, eight independent radiologists compared the image quality of the screen/film system to that of the novel flat panel detector. RESULTS: Phases I and II revealed a difference in the image quality achieved by the standard screen/film system and the digital detector system to the advantage of the digital detector system. In 77 of 84 patients (91.7 %), phase III showed equal image quality after a 50 % reduction in the X-ray dose. In 3 cases (3.6 %) the image quality and the level of contrast were better. No unified statement could be made for 4 patients (4.7 %). CONCLUSION: Digital imaging of skeletal disorders using the novel flat panel detector makes it possible to reduce the X-ray dose by 50 % with equal or even better image quality.

Molecular signatures of a disturbed nasal barrier function in the primary tissue of Wegener's granulomatosis.

Wegener's granulomatosis (WG) is a complex autoimmune disease of unknown etiology, frequently involving localized inflammation of the nasal mucosa as an early manifestation. The current hypothesis suggests that the disease is triggered by a disturbed interaction between genetic and environmental effects, such as an altered microflora at mucosal layers. In this study, a systematic assessment of 49 transcripts with potential pathophysiological relevance was performed using quantitative real-time PCR in nasal mucosa samples of more than 80 individuals, including normal control (NC) individuals and disease controls. In addition, colonization with Staphylococcus aureus was quantified in the same individuals to assess its impact on transcriptomic signatures. Transcription profiles show an increased heterogeneity in diseased individuals. In all, 10 transcripts were identified to be differentially expressed (P≤0.05, false discovery rate ≤0.05) between patients with WG and NC individuals. These transcripts include antimicrobial peptides (human ß-defensin (DEFB)1: fold-change WG vs. controls: +4.45, lysozyme: -3.4, DEFB4 and S100A7 (S100 calcium-binding protein A7): both "switched on" in WG), innate immune receptors (Toll-like receptor 4: -2.1, NOD-like receptor C3: -2.1, scavenger receptor CD36: +2.9), and cytokines (interferon-γ: -14, transforming growth factor-ß 1: -1.4, interleukin-17D: -2.7). These transcriptional profiles are independent of S. aureus colonization. This study for the first time describes that, on the basis of data obtained from the primary nasal tissue, WG exhibits molecular features that allow its differentiation from other inflammatory disorders with involvement of the nasal mucosa. Further studies based on these findings may enable the identification of subphenotypes, which are currently discussed as an important target for a personalized medicine approach, aiming to reduce side effects and the number of therapy non-responders.

Analysis of oxidative degradation products of 2,4,6-trichlorophenol treated with air ions.

The analysis of oxidative degradation products of 2,4,6-trichlorophenol (TCP) treated with air ions, which are generated by electric discharge, is reported. Due to the complex nature of the degradation products, a combination of different detection techniques was employed to characterize them. The oxidative degradation of TCP is usually dependent on the treating approaches, and in this system, a stepwise degradation, beginning with the formation of a major product 2,6-dichloro-1,4-benzenediol as well as other minor ones (e.g., 3,5-dichlorocatechol) via substitution, is first proposed through a detailed analysis of GC/MS, etc., though some chromogenic quinones can transiently be present. Furthermore, high dechlorination (53%) was observed for TCP after a 60-min treatment, indicating that air ions can serve as an efficient dechlorination means.