680 research outputs found

    Electronic polarization in pentacene crystals and thin films

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    Electronic polarization is evaluated in pentacene crystals and in thin films on a metallic substrate using a self-consistent method for computing charge redistribution in non-overlapping molecules. The optical dielectric constant and its principal axes are reported for a neutral crystal. The polarization energies P+ and P- of a cation and anion at infinite separation are found for both molecules in the crystal's unit cell in the bulk, at the surface, and at the organic-metal interface of a film of N molecular layers. We find that a single pentacene layer with herring-bone packing provides a screening environment approaching the bulk. The polarization contribution to the transport gap P=(P+)+(P-), which is 2.01 eV in the bulk, decreases and increases by only ~ 10% at surfaces and interfaces, respectively. We also compute the polarization energy of charge-transfer (CT) states with fixed separation between anion and cation, and compare to electroabsorption data and to submolecular calculations. Electronic polarization of ~ 1 eV per charge has a major role for transport in organic molecular systems with limited overlap.Comment: 10 revtex pages, 6 PS figures embedde

    Cost-effectiveness in extracorporeal life support in critically ill adults in the Netherlands

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    Background: Extracorporeal life support (ECLS) is used to support the cardiorespiratory function in case of severe cardiac and/or respiratory failure in critically ill patients. According to the ELSO guidelines ECLS should be considered when estimated mortality risk approximates 80%. ECLS seems an efficient therapy in terms of survival benefit, but no undisputed evidence is delivered yet. The aim of the study is to assess the health-related quality of life after ECLS treatment and its cost effectiveness. Methods: We will perform a prospective observational cohort study. All adult patients who receive ECLS in the participating centers will be included. Exclusion criteria are patients in whom the ECLS is only used to bridge a procedure (like a high risk percutaneous coronary intervention or surgery) or the absence of informed consent. Data collection includes patient characteristics and data specific for ECLS treatment. Severity of illness and mortality risk is measured as precisely as possible using measurements for the appropriate age group and organ failure. For analyses on survival patients will act as their own control as we compare the actual survival with the estimated mortality on initiation of ECLS if conservative treatment would have been continued. Survivors are asked to complete validated questionnaires on health related quality of life (EQ5D-5 L) and on medical consumption and productivity losses (iMTA/iPCQ) at 6 and 12 months. Also the health related quality of life 1 month prior to ECLS initiation will be obtained by a questionnaire, if needed provided by relatives. With an estimated overall survival of 62% 210 patients need to be recruited to make a statement on cost effectiveness for all ECLS indications. Discussion: If our hypothesis that ECLS treatment is cost-effective is confirmed by this prospective study this could lead to an even broader use of ECLS treatment

    Favorable resuscitation characteristics in patients undergoing extracorporeal cardiopulmonary resuscitation:A secondary analysis of the INCEPTION-trial

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    Introduction: Extracorporeal cardiopulmonary resuscitation (ECPR) is increasingly used as a supportive treatment for refractory out-of-hospital cardiac arrest (OHCA). Still, there is a paucity of data evaluating favorable and unfavorable prognostic characteristics in patients considered for ECPR. Methods: We performed a previously unplanned post-hoc analysis of the multicenter randomized controlled INCEPTION-trial. The study group consisted of patients receiving ECPR, irrespective of initial group randomization. The patients were divided into favorable survivors (cerebral performance category [CPC] 1–2) and unfavorable or non-survivors (CPC 3–5).Results: In the initial INCEPTION-trial, 134 patients were randomized. ECPR treatment was started in 46 (66%) of 70 patients in the ECPR treatment arm and 3 (4%) of 74 patients in the conventional treatment arm. No statistically significant differences in baseline characteristics, medical history, or causes of arrest were observed between survivors (n = 5) and non-survivors (n = 44). More patients in the surviving group had a shockable rhythm at the time of cannulation (60% vs. 14%, p = 0.037), underwent more defibrillation attempts (13 vs. 6, p = 0.002), and received higher dosages of amiodarone (450 mg vs 375 mg, p = 0.047) despite similar durations of resuscitation maneuvers. Furthermore, non-survivors more frequently had post-ECPR implantation adverse events. Conclusion: The persistence of ventricular arrhythmia is a favorable prognostic factor in patients with refractory OHCA undergoing an ECPR-based treatment. Future studies are warranted to confirm this finding and to establish additional prognostic factors. Clinical trial Registration: clinicaltrials.gov</p

    Health-related quality of life one year after refractory cardiac arrest treated with conventional or extracorporeal CPR: a secondary analysis of the INCEPTION-trial

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    Background: Prospective, trial-based data comparing health-related quality of life (HRQoL) in patients surviving out-of-hospital cardiac arrest (OHCA) through extracorporeal cardiopulmonary resuscitation (ECPR) or conventional CPR (CCPR) are scarce. We aimed to determine HRQoL during 1-year after refractory OHCA in patients treated with ECPR and CCPR. Methods: We present a secondary analysis of the multicenter INCEPTION-trial, which studied the effectiveness of ECPR versus CCPR in patients with refractory OHCA. HRQoL was prospectively assessed using the EQ-5D-5L questionnaire. Poor HRQoL was pragmatically defined as an EQ-5D-5L health utility index (HUI) &gt; 1 SD below the age-adjusted norm. We used mixed linear models to assess the difference in HRQoL over time and univariable analyses to assess factors potentially associated with poor HRQoL. Results: A total of 134 patients were enrolled, and hospital survival was 20% (27 patients). EQ-5D-5L data were available for 25 patients (5 ECPR and 20 CCPR). One year after OHCA, the estimated mean HUI was 0.73 (0.05) in all patients, 0.84 (0.12) in ECPR survivors, and 0.71 (0.05) in CCPR survivors (p-value 0.31). Eight (32%) survivors had a poor HRQoL. HRQoL was good in 17 (68%) patients, with 100% in ECPR survivors versus 60% in CCPR survivors (p-value 0.14). Conclusion: One year after refractory OHCA, 68% of the survivors had a good HRQoL. We found no statistically significant difference in HRQoL one year after OHCA in patients treated with ECPR compared to CCPR. However, numerical differences may be clinically relevant in favor of ECPR.</p

    Health-related quality of life one year after refractory cardiac arrest treated with conventional or extracorporeal CPR: a secondary analysis of the INCEPTION-trial

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    Background: Prospective, trial-based data comparing health-related quality of life (HRQoL) in patients surviving out-of-hospital cardiac arrest (OHCA) through extracorporeal cardiopulmonary resuscitation (ECPR) or conventional CPR (CCPR) are scarce. We aimed to determine HRQoL during 1-year after refractory OHCA in patients treated with ECPR and CCPR. Methods: We present a secondary analysis of the multicenter INCEPTION-trial, which studied the effectiveness of ECPR versus CCPR in patients with refractory OHCA. HRQoL was prospectively assessed using the EQ-5D-5L questionnaire. Poor HRQoL was pragmatically defined as an EQ-5D-5L health utility index (HUI) &gt; 1 SD below the age-adjusted norm. We used mixed linear models to assess the difference in HRQoL over time and univariable analyses to assess factors potentially associated with poor HRQoL. Results: A total of 134 patients were enrolled, and hospital survival was 20% (27 patients). EQ-5D-5L data were available for 25 patients (5 ECPR and 20 CCPR). One year after OHCA, the estimated mean HUI was 0.73 (0.05) in all patients, 0.84 (0.12) in ECPR survivors, and 0.71 (0.05) in CCPR survivors (p-value 0.31). Eight (32%) survivors had a poor HRQoL. HRQoL was good in 17 (68%) patients, with 100% in ECPR survivors versus 60% in CCPR survivors (p-value 0.14). Conclusion: One year after refractory OHCA, 68% of the survivors had a good HRQoL. We found no statistically significant difference in HRQoL one year after OHCA in patients treated with ECPR compared to CCPR. However, numerical differences may be clinically relevant in favor of ECPR.</p

    An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

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    For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
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