“Medical necessity” (MedN) is the central regulatory concept for decisions about which services are covered by German statutory health insurance. Despite its seeming objectivity and dependence on physicians’ expert judgment, the concept is by no means clearly defined.
Arguments
In this first of five planned papers on the conceptual analysis of MedN from the perspectives of philosophy and ethics of medicine, law, and (social) medicine, the focus lies on systemizing ongoing controversies.
Conclusion
Our goal is to come up with a so far missing foundation for detailed debates. We aim to clarify MedN’s conceptual structure, function, contextuality, and ambiguities as well as the fundamental limits of conceptual investigations for the normative questions at issue of regulating medical services.
The Seebeck coefficient S is an important performance characteristic of thermoelectric materials. In this paper we establish the fact that quantum
dots and single-electron tunneling devices with narrow, well-spaced energy levels and sharp transmission resonances have a
Seebeck coefficient independent of material parameters. By employing a delta function for the transmission resonances we arrive
at an intrinsic expression for S in terms of the fundamental electronic charge e. We further confirm the validity of our result in the case of a transmission resonance with finite width. 相似文献
White tea (WT) is rich in flavan‐3‐ols as green tea (GT) and might provide health protective effects due to the strong antioxidant properties of flavan‐3‐ols. Since intervention studies with WT are lacking, we evaluated the effects of WT consumption on antioxidant status, antioxidant capacity and biomarkers of oxidative stress compared to water and GT. After an overnight fast, 70 healthy non‐smokers were randomized to consume 600 mL of WT, GT or water (control). Plasma (epi‐)catechin and epi(gallo)catechingallate, antioxidant capacity (Folin assay, trolox equivalent antioxidant capacity test), 8‐iso‐prostaglandin F2α, ascorbic acid and uric acid were determined before and several times within 8 h after consumption. DNA strand breaks were measured in vivo and ex vivo (H2O2 stimulation) in leukocytes. Plasma flavan‐3‐ols significantly increased after WT and GT ingestion. Trolox equivalent antioxidant capacity was lower after 5 h in controls versus WT (p=0.031) and GT (p=0.005). Folin‐Ciocalteu reducing capacity, ascorbic and uric acid as well as markers of oxidative stress (8‐iso‐prostaglandin‐F2α, DNA strand breaks) were not affected by the beverages. A short‐term increase of catechins does not change plasma antioxidant capacity in healthy subjects. Conclusions with respect to health protective effects of WT and GT on the basis of these biomarkers can, thus, not be drawn. 相似文献
High quality domain ontologies are essential for successful employment of semantic Web services. However, their acquisition is difficult and costly, thus hampering the development of this field. In this paper we report on the first stage of research that aims to develop (semi-)automatic ontology learning tools in the context of Web services that can support domain experts in the ontology building task. The goal of this first stage was to get a better understanding of the problem at hand and to determine which techniques might be feasible to use. To this end, we developed a framework for (semi-)automatic ontology learning from textual sources attached to Web services. The framework exploits the fact that these sources are expressed in a specific sublanguage, making them amenable to automatic analysis. We implement two methods in this framework, which differ in the complexity of the employed linguistic analysis. We evaluate the methods in two different domains, verifying the quality of the extracted ontologies against high quality hand-built ontologies of these domains.
Our evaluation lead to a set of valuable conclusions on which further work can be based. First, it appears that our method, while tailored for the Web services context, might be applicable across different domains. Second, we concluded that deeper linguistic analysis is likely to lead to better results. Finally, the evaluation metrics indicate that good results can be achieved using only relatively simple, off the shelf techniques. Indeed, the novelty of our work is not in the used natural language processing methods but rather in the way they are put together in a generic framework specialized for the context of Web services. 相似文献
In the past decade,there is an increasing interest in making Silicon-On-Insulator(SOI) films by high dose oxygen or nitrogen implantation into silicon,which will replaceSOS(Silicon-On-Sapphire) to fabricate the high-speed,no latch-up... 相似文献
Because of high efficiency, low environmental impacts and a potential role in transforming our energy system into a hydrogen economy, fuel cells are often considered as a key technology for a sustainable energy supply. However, the future framing conditions under which stationary fuel cells have to prove their technical and economic competitiveness are most likely characterised by a reduced demand for space heating, and a growing contribution of renewable energy sources to heat and electricity supply, which both directly limit the potential for combined heat and power generation, and thus also for fuel cells. Taking Germany as a case study, this paper explores the market potential of stationary fuel cells under the structural changes of the energy demand and supply system required to achieve a sustainable energy supply. Results indicate that among the scenarios analysed it is in particular a strategy oriented towards ambitious CO2-reduction targets, which due to its changes in the supply structure is in a position to mobilise a market potential that might be large enough for a successful fuel cell commercialisation. However, under the conditions of a business-as-usual trajectory the sales targets of fuel cell manufacturers cannot be met. 相似文献
In this paper we describe the achievements and pitfalls encounteredin doing structure predictions of protein mutants using moleculardynamics simulation techniques in which properties of atomsare slowly changed as a function of time. Basically the methodconsists of a thermodynamic integration (slow growth) calculationused for free energy determination, but aimed at structure prediction;this allows for a fast determination of the mutant structure.We compared the calculated structure of the mutants Met222Ala,Met222Phe and Met222Gln of subtilisin BPN' with the respectiveX-ray structures and found good agreement between predictedand X-ray structure. The conformation of the residue subjectto the mutation is relatively easy to predict and is mainlydetermined by packing criteria. When the side chain has polargroups its exact orientation may pose problems; long-range Coulombinteractions may generate a polarization feedback involvingsystem relaxation times beyond the simulation time. Changesinduced in the environment are harder to predict using thismethod. In particular, rearrangement of the hydration structurewas difficult to predict correctly, probably because of thelong relaxation times. In all conversions made the changes observedin the environment were found to be history-dependent and inparticular the hydrogen bonding patterns provided evidence formetastable substates. In all cases the structure predicted wascompared with available kinetic data and the reduced activitycould be explained in terms of changes in the configurationof the active site. 相似文献