31 research outputs found

    Disclosing conflicts of interest in German publications concerning health services research

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    <p>Abstract</p> <p>Background</p> <p>The influence of the pharmaceutical industry and other stakeholders on medical science has been increasingly criticised. When dealing with conflicts of interest in scientific publications it is important to ensure the best possible transparency. The objective of this work is to examine the disclosure practice of financial and non-financial conflicts of interest in German language publications concerning health services research for the first time.</p> <p>Methods</p> <p>We performed a systematic literature search in the PubMed data base using the MeSH term "health services research". The review was conducted on July 10, 2006, setting the limits "dates: published in the last 2 years" and "languages: German" (only articles with abstracts). 124 articles in 31 magazines were found. In the magazines the instructions for authors were examined as to whether a statement on conflicts of interest is expected – and if, in which form. Regarding the articles in the journals which require a statement, we examined whether the statement is explicitly published. The results are descriptively represented.</p> <p>Results</p> <p>13 magazines (42%) do not require any statement on conflicts of interest, whereas 18 journals (58%) expect a statement. Two of these 18 magazines refer explicitly to the uniform requirements of the <it>International Committee of the Medical Journal Editors </it>(ICMJE); the remaining 16 magazines give differently accentuated instructions on how to disclose conflicts of interest, whereby the focus is primarily on financial issues. A statement on conflicts of interest is explicitly published in 11 of the 71 articles (15%) which are found in the magazines that require a statement with the submission of a manuscript. Related to the total number of included articles, this means that the reader explicitly receives information on potential conflicts of interest in 9% of the cases (11 of 124 articles). Statements of others that are involved in the publication process (reviewers, editors) are not available in any of the articles examined.</p> <p>Conclusion</p> <p>A better sensitization for possible conflicts of interest in German publications concerning health services research is necessary. We suggest tightening the criteria for disclosure in the instructions for authors in the scientific journals. Among other things the equivalent consideration of financial and non-financial conflicts of interest as well as the obligatory publication of the statements should be part of good practice.</p

    Plasma-neutral interactions in the lower thermosphere-ionosphere : The need for in situ measurements to address focused questions

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    The lower thermosphere-ionosphere (LTI) is a key transition region between Earth's atmosphere and space. Interactions between ions and neutrals maximize within the LTI and in particular at altitudes from 100 to 200 km, which is the least visited region of the near-Earth environment. The lack of in situ co-temporal and co-spatial measurements of all relevant parameters and their elusiveness to most remote-sensing methods means that the complex interactions between its neutral and charged constituents remain poorly characterized to this date. This lack of measurements, together with the ambiguity in the quantification of key processes in the 100-200 km altitude range affect current modeling efforts to expand atmospheric models upward to include the LTI and limit current space weather prediction capabilities. We present focused questions in the LTI that are related to the complex interactions between its neutral and charged constituents. These questions concern core physical processes that govern the energetics, dynamics, and chemistry of the LTI and need to be addressed as fundamental and long-standing questions in this critically unexplored boundary region. We also outline the range of in situ measurements that are needed to unambiguously quantify key LTI processes within this region, and present elements of an in situ concept based on past proposed mission concepts.Peer reviewe

    Lower-thermosphere–ionosphere (LTI) quantities: current status of measuring techniques and models

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    The lower-thermosphere-ionosphere (LTI) system consists of the upper atmosphere and the lower part of the ionosphere and as such comprises a complex system coupled to both the atmosphere below and space above. The atmospheric part of the LTI is dominated by laws of continuum fluid dynamics and chemistry, while the ionosphere is a plasma system controlled by electromagnetic forces driven by the magnetosphere, the solar wind, as well as the wind dynamo. The LTI is hence a domain controlled by many different physical processes. However, systematic in situ measurements within this region are severely lacking, although the LTI is located only 80 to 200 km above the surface of our planet. This paper reviews the current state of the art in measuring the LTI, either in situ or by several different remote-sensing methods. We begin by outlining the open questions within the LTI requiring high-quality in situ measurements, before reviewing directly observable parameters and their most important derivatives. The motivation for this review has arisen from the recent retention of the Daedalus mission as one among three competing mission candidates within the European Space Agency (ESA) Earth Explorer 10 Programme. However, this paper intends to cover the LTI parameters such that it can be used as a background scientific reference for any mission targeting in situ observations of the LTI.Peer reviewe

    Limited dCTP Availability Accounts for Mitochondrial DNA Depletion in Mitochondrial Neurogastrointestinal Encephalomyopathy (MNGIE)

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    Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a severe human disease caused by mutations in TYMP, the gene encoding thymidine phosphorylase (TP). It belongs to a broader group of disorders characterized by a pronounced reduction in mitochondrial DNA (mtDNA) copy number in one or more tissues. In most cases, these disorders are caused by mutations in genes involved in deoxyribonucleoside triphosphate (dNTP) metabolism. It is generally accepted that imbalances in mitochondrial dNTP pools resulting from these mutations interfere with mtDNA replication. Nonetheless, the precise mechanistic details of this effect, in particular, how an excess of a given dNTP (e.g., imbalanced dTTP excess observed in TP deficiency) might lead to mtDNA depletion, remain largely unclear. Using an in organello replication experimental model with isolated murine liver mitochondria, we observed that overloads of dATP, dGTP, or dCTP did not reduce the mtDNA replication rate. In contrast, an excess of dTTP decreased mtDNA synthesis, but this effect was due to secondary dCTP depletion rather than to the dTTP excess in itself. This was confirmed in human cultured cells, demonstrating that our conclusions do not depend on the experimental model. Our results demonstrate that the mtDNA replication rate is unaffected by an excess of any of the 4 separate dNTPs and is limited by the availability of the dNTP present at the lowest concentration. Therefore, the availability of dNTP is the key factor that leads to mtDNA depletion rather than dNTP imbalances. These results provide the first test of the mechanism that accounts for mtDNA depletion in MNGIE and provide evidence that limited dNTP availability is the common cause of mtDNA depletion due to impaired anabolic or catabolic dNTP pathways. Thus, therapy approaches focusing on restoring the deficient substrates should be explored

    The Architecture of the Adhesive Apparatus of Cultured Osteoclasts: From Podosome Formation to Sealing Zone Assembly

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    BACKGROUND: Osteoclasts are bone-degrading cells, which play a central role in physiological bone remodeling. Unbalanced osteoclast activity is largely responsible for pathological conditions such as osteoporosis. Osteoclasts develop specialized adhesion structures, the so-called podosomes, which subsequently undergo dramatic reorganization into sealing zones. These ring-like adhesion structures, which delimit the resorption site, effectively seal the cell to the substrate forming a diffusion barrier. The structural integrity of the sealing zone is essential for the cell ability to degrade bone, yet its structural organization is poorly understood. PRINCIPAL FINDINGS: Combining high-resolution scanning electron microscopy with fluorescence microscopy performed on the same sample, we mapped the molecular architecture of the osteoclast resorptive apparatus from individual podosomes to the sealing zone, at an unprecedented resolution. Podosomes are composed of an actin-bundle core, flanked by a ring containing adhesion proteins connected to the core via dome-like radial actin fibers. The sealing zone, hallmark of bone-resorbing osteoclasts, consists of a dense array of podosomes communicating through a network of actin filaments, parallel to the substrate and anchored to the adhesive plaque domain via radial actin fibers. SIGNIFICANCE: The sealing zone of osteoclasts cultured on bone is made of structural units clearly related to individual podosomes. It differs from individual or clustered podosomes in the higher density and degree of inter-connectivity of its building blocks, thus forming a unique continuous functional structure connecting the cell to its extracellular milieu. Through this continuous structure, signals reporting on the substrate condition may be transmitted to the whole cell, modulating the cell response under physiological and pathological conditions

    Synthetic turbulence using artificial boundary layers

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    Lagrangian vortex sheets for animating fluids

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