First-principle study of excitonic self-trapping in diamond

We present a first-principles study of excitonic self-trapping in diamond. Our calculation provides evidence for self-trapping of the 1s core exciton and gives a coherent interpretation of recent experimental X-ray absorption and emission data. Self-trapping does not occur in the case of a single valence exciton. We predict, however, that self-trapping should occur in the case of a valence biexciton. This process is accompanied by a large local relaxation of the lattice which could be observed experimentally.Comment: 12 pages, RevTex file, 3 Postscript figure

Does femtosecond time-resolved second-harmonic generation probe electron temperatures at surfaces?

Femtosecond pump-probe second-harmonic generation (SHG) and transient linear reflectivity measurements were carried out on polycrystalline Cu, Ag and Au in air to analyze whether the electron temperature affects Fresnel factors or nonlinear susceptibilities, or both. Sensitivity to electron temperatures was attained by using photon energies near the interband transition threshold. We find that the nonlinear susceptibility carries the electron temperature dependence in case of Ag and Au, while for Cu the dependence is in the Fresnel factors. This contrasting behavior emphasizes that SHG is not a priori sensitive to electron dynamics at surfaces or interfaces, notwithstanding its cause.Comment: 11 pages, 4 figure

Swift Heavy Ion Induced Modification Studies of C60 Thin Films

Modification induced by 110 MeV Ni ion irradiated thin film samples of C60 on Si and quartz substrates were studied at various fluences. The pristine and irradiated samples were investigated using Raman spectroscopy, electrical conductivity and optical absorption spectroscopy. The Raman data and band gap measurements indicate that swift ions at low fluences result in formations that involve multiple molecular units like dimer or polymer. High fluence irradiation resulted in sub-molecular formations and amorphous semiconducting carbon, indicating overall damage of the fullerene molecules. These sub-molecular units have been identified with nanocrystalline diamond and nanocrystalline graphite like formations.Comment: 7 pages, 29 references and 9 figures submitted to J. Appl. Phy

The SCARE Statement: Consensus-based surgical case report guidelines

AbstractIntroductionCase reports have been a long held tradition within the surgical literature. Reporting guidelines can improve transparency and reporting quality. However, recent consensus-based guidelines for case reports (CARE) are not surgically focused. Our objective was to develop surgical case report guidelines.MethodsThe CARE statement was used as the basis for a Delphi consensus. The Delphi questionnaire was administered via Google Forms and conducted using standard Delphi methodology. A multidisciplinary group of surgeons and others with expertise in the reporting of case reports were invited to participate. In round one, participants stated how each item of the CARE statement should be changed and what additional items were needed. Revised and additional items from round one were put forward into a further round, where participants voted on the extent of their agreement with each item, using a nine-point Likert scale, as proposed by the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) working group.ResultsIn round one, there was a 64% (38/59) response rate. Following adjustment of the guideline with the incorporation of recommended changes, round two commenced and there was an 83% (49/59) response rate. All but one of the items were approved by the participants, with Likert scores 7–9 awarded by >70% of respondents. The final guideline consists of a 14-item checklist.ConclusionWe present the SCARE Guideline, consisting of a 14-item checklist that will improve the reporting quality of surgical case reports

The SCARE Statement: Consensus-based surgical case report guidelines

Introduction: Case reports have been a long held tradition within the surgical literature. Reporting guidelines can improve transparency and reporting quality. However, recent consensus-based guidelines for case reports (CARE) are not surgically focused. Our objective was to develop surgical case report guidelines.Methods: The CARE statement was used as the basis for a Delphi consensus. The Delphi questionnaire was administered via Google Forms and conducted using standard Delphi methodology. A multidisciplinary group of surgeons and others with expertise in the reporting of case reports were invited to participate. In round one, participants stated how each item of the CARE statement should be changed and what additional items were needed. Revised and additional items from round one were put forward into a further round, where participants voted on the extent of their agreement with each item, using a nine-point Likert scale, as proposed by the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) working group.Results: In round one, there was a 64% (38/59) response rate. Following adjustment of the guideline with the incorporation of recommended changes, round two commenced and there was an 83% (49/59) response rate. All but one of the items were approved by the participants, with Likert scores 7–9 awarded by >70% of respondents. The final guideline consists of a 14-item checklist.Conclusion: We present the SCARE Guideline, consisting of a 14-item checklist that will improve the reporting quality of surgical case reports.</p