69 research outputs found

    Recommendations for implementing stereotactic radiotherapy in peripheral stage IA non-small cell lung cancer: report from the Quality Assurance Working Party of the randomised phase III ROSEL study

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    <p>Abstract</p> <p>Background</p> <p>A phase III multi-centre randomised trial (ROSEL) has been initiated to establish the role of stereotactic radiotherapy in patients with operable stage IA lung cancer. Due to rapid changes in radiotherapy technology and evolving techniques for image-guided delivery, guidelines had to be developed in order to ensure uniformity in implementation of stereotactic radiotherapy in this multi-centre study.</p> <p>Methods/Design</p> <p>A Quality Assurance Working Party was formed by radiation oncologists and clinical physicists from both academic as well as non-academic hospitals that had already implemented stereotactic radiotherapy for lung cancer. A literature survey was conducted and consensus meetings were held in which both the knowledge from the literature and clinical experience were pooled. In addition, a planning study was performed in 26 stage I patients, of which 22 were stage 1A, in order to develop and evaluate the planning guidelines. Plans were optimised according to parameters adopted from RTOG trials using both an algorithm with a simple homogeneity correction (Type A) and a more advanced algorithm (Type B). Dose conformity requirements were then formulated based on these results.</p> <p>Conclusion</p> <p>Based on current literature and expert experience, guidelines were formulated for this phase III study of stereotactic radiotherapy versus surgery. These guidelines can serve to facilitate the design of future multi-centre clinical trials of stereotactic radiotherapy in other patient groups and aid a more uniform implementation of this technique outside clinical trials.</p

    Philosophy of law in the Soviet Union and the people’s democracies

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    The fate of Marxism in the Soviet Union and the people’s democracies as the former’s extension owing to post-WWII occupation was from the beginning sealed by Bolshevism, that is, the politico-ideological domination and use of the scholarly domain as well, made to self-close in a merely justificatory role. There may have been attempts at opening, even if only conceivable within—i.e. preserving at the same time—this framework function. In the present conspectus, the limiting positions are occupied by the Soviet Union and the German Democratic Republic, completed by after-1968 Czechoslovakia, as well as Yugoslavia and pre-1968 Czechoslovakia, representing the substitute-to-religion dogmatic side, exclusively politically motivated in the former and subordinated to a humanising tendency in the latter case, on the one hand, and Poland, dedicated to a purely analytical approach, in which Marxism has simply no relevance, on the other. Hungary, treated in an earlier paper by the author, was in-between, taking Marxism seriously but mostly as a methodology, and thereby able to foster live debates. All that notwithstanding, there has been quite a few progressive moves also in Romania and Bulgaria in this specific academic field. Turning topoi of the discussions were, chronologically but recurrent transubstantiatedly, the exclusivity of Vyshinsky’s socialist normativism, the consequences ensuing from the law’s superstructural nature, the discontinuity vs. continuity of law in historical development, and, in the background, the dilemma of the ontological/epistemological understanding of Marxism, the latter standing for a rigid Leninist reducibility of law to its material substratum as the product of sheer reflection, and the former enabling to develop the law’s relative autonomy as in Lukács’ posthumous ontology. On the final analysis, all these forced paths made a whole region’s efforts to be belated as compared to international developments, the fact notwithstanding those outstanding achievements were born especially on the fields of legal ontology and sociology, as well as the legal methodology and particularly that of the comparison of laws

    Three-Layered Photovoltaic Cell with an Enlarged Photoactive Region of Codeposited Dyes

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    Three-layered organic solar cells with an interlayer of codeposited dyes of p-type Copper Phthalocyanine (CuPc) and n-type 5,10,15,20-Tetra (4-Pyridil) 21H,23H-Porphine (TPyP) between the respective dye layers were prepared and characterised. The analysis of their dark current-voltage (IUI - U) characteristics at room temperature has been presented in order to elucidate the conduction mechanisms and to evaluate the cell parameters. The analysis of photovoltaic properties shows that the photocurrent of three-layered cells is about ten times larger than that of a double layered cell, due to the efficient carrier photogeneration in the code-posited layer. The best power conversion efficiency, at 0.35% was obtained under illumination with monochromatic light of 30 μ\muW cm2^{-2}, at 520 nm.Nous avons élaboré des cellules photovoltaïques avec trois couches minces de colorants organiques entre deux électrodes : ITO et Al. Les cellules ont été faites en utilisant CuPc comme semi-conducteur de type-p et TPyP comme semi-conducteur de type-n. Entre les deux couches de CuPc et TPyP, une couche mince de CuPc+TPyP a été deposée par co-évaporation thermique des deux matériaux organiques. L'analyse des caractéristiques électriques (IUI - U) des cellules dans l'obscurité est présentée pour comprendre les mécanismes mis en jeu et pour évaluer leur paramètres électriques. L'analyse des propriétés photovoltaïques a montré que le photocourant des cellules avec trois couches minces est 10 fois plus grand que celui mesuré sur les cellules à deux couches minces, grâce à une création plus efficace des photoporteurs dans la couche mince co-évaporée. Le rendement de conversion énergétique est maximal à 0,35% pour la lumière avec une longueur d'onde de 520 nm et une intensité lumineuse de 30 μ\muW cm2^{-2}

    Free trade versus strategic trade as a choice between two 'second-best' policies A symmetric versus asymmetric information analysis

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    SIGLEAvailable from British Library Document Supply Centre-DSC:3597.9512(no 2928) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    Lung dose threshold for interstitial pneumonitis for patients undergoing total body irradiation.

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    Purpose: To quantify dose response for lung irradiation and other predictors associated with IP (interstitial pneumonitis) for patients undergoing TBI (total body irradiation). Methods: A literature search on TBI identified 42 publications (including 3194 patients) that reported IP incidence rates along with lung doses, dose rates, dose fractionation schemes, and chemotherapy agents. Mean lung dose from these different fractionation regimens was converted to equivalent dose in 2 Gy fractions (EQD2) (a/b = 3 Gy). Data from fractionated and single fraction regimen subsets were analyzed separately and adjusted for incomplete lung tissue repair (half-life = 4 h) for fractionation schemes with \u3e1 fraction per day (EQD2-repair). Cox logistic regression was performed using multivariate analysis to identify predictors of IP. Dose response functions were generated using two different models and recursive partitioning was used to identify a lung dose threshold. Results: Cox logistic regression models found that EQD2, EQD2-repair, and chemotherapy agent cyclophosphamide (Cy) are significant predictors of IP. The models failed to deliver a reasonable dose response curve. Discrete data analysis of multi-fraction per day regimens identified a lung dose threshold of 7 Gy and 7.6 Gy for EQD2 and EQD2-repair, respectively, below which no IP toxicity was observed. Dose rate was not found to be an independent risk factor for IP. The most common chemotherapy agent was found to be Cy with 80% prevalence and mean dose of 120 mg/kg. Conclusion: Mean lung dose and Cy were identified as predictors of IP but the prediction model did not accurately reflect the IP rates of published data. Restricting lung EQD2 below the thresholds of 7.0 Gy and 7.6 Gy identified here for single and multiple fraction per day regimens, respectively, results in negligible IP incidence irrespective of dose rate. These lung doses are easily achievable with lung blocks or intensity modulation for standard 12 Gy prescription regimens
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