Hoidon vaikuttavuuden arviointi 15D-mittarilla

English summaryPeer reviewe

Quantized evolution of the plasmonic response in a stretched nanorod

Quantum aspects, such as electron tunneling between closely separated metallic nanoparticles, are crucial for understanding the plasmonic response of nanoscale systems. We explore quantum effects on the response of the conductively coupled metallic nanoparticle dimer. This is realized by stretching a nanorod, which leads to the formation of a narrowing atomic contact between the two nanorod ends. Based on first-principles time-dependent density-functional-theory calculations, we find a discontinuous evolution of the plasmonic response as the nanorod is stretched. This is especially pronounced for the intensity of the main charge-transfer plasmon mode. We show the correlation between the observed discontinuities and the discrete nature of the conduction channels supported by the formed atomic-sized junction.Comment: Main text: 6 pages, 2 figures; Supplemental Material: 5 pages, 4 figure

Nanoplasmonics simulations at the basis set limit through completeness-optimized, local numerical basis sets

We present an approach for generating local numerical basis sets of improving accuracy for first-principles nanoplasmonics simulations within time-dependent density functional theory. The method is demonstrated for copper, silver, and gold nanoparticles that are of experimental interest but computationally demanding due to the semi-core d-electrons that affect their plasmonic response. The basis sets are constructed by augmenting numerical atomic orbital basis sets by truncated Gaussian-type orbitals generated by the completeness-optimization scheme, which is applied to the photoabsorption spectra of homoatomic metal atom dimers. We obtain basis sets of improving accuracy up to the complete basis set limit and demonstrate that the performance of the basis sets transfers to simulations of larger nanoparticles and nanoalloys as well as to calculations with various exchange-correlation functionals. This work promotes the use of the local basis set approach of controllable accuracy in first-principles nanoplasmonics simulations and beyond.Comment: 11 pages, 6 figure

Kohn-Sham decomposition in real-time time-dependent density-functional theory: An efficient tool for analyzing plasmonic excitations

The real-time-propagation formulation of time-dependent density-functional theory (RT-TDDFT) is an efficient method for modeling the optical response of molecules and nanoparticles. Compared to the widely adopted linear-response TDDFT approaches based on, e.g., the Casida equations, RT-TDDFT appears, however, lacking efficient analysis methods. This applies in particular to a decomposition of the response in the basis of the underlying single-electron states. In this work, we overcome this limitation by developing an analysis method for obtaining the Kohn-Sham electron-hole decomposition in RT-TDDFT. We demonstrate the equivalence between the developed method and the Casida approach by a benchmark on small benzene derivatives. Then, we use the method for analyzing the plasmonic response of icosahedral silver nanoparticles up to Ag$_{561}$. Based on the analysis, we conclude that in small nanoparticles individual single-electron transitions can split the plasmon into multiple resonances due to strong single-electron-plasmon coupling whereas in larger nanoparticles a distinct plasmon resonance is formed.Comment: 11 pages, 3 figure

Tyytyväinen potilas = laadukas terveydenhuolto?

Hoidon laadun luotettava mittaaminen on laadun kehittämisen ja hoitolaitosten välisten vertailujen edellytys. Kokonaispotilas­tyytyväisyys ei sovellu yksinään hoidon laadun sijaismuuttujaksi

Molecular-dynamics simulation of the growth of diamondlike films by energetic carbon-atom beams

The growth of diamondlike films and overlayers by the deposotion of energetic carbon atoms has been investigated by molecular-dynamics simulations. The interatomic many-atom potential suggested by Tersoff is used. The structurel analysis of the grown films shows that there is an energy window between 40 and 70 eV for the deposited atoms where the growth most closely results in dense diamondlike structure. This observation supports earlier experimental suggestions for optimal deposition conditions.Peer reviewe

Influence of van der Waals forces on the adsorption structure of benzene on silicon studied using density functional theory

Two different adsorption configurations of benzene on the Si(001)-(2 x 1) surface, the tight-bridge and butterfly structures, were studied using density functional theory. Several exchange and correlation functionals were used, including the recently developed van der Waals density functional (vdW-DF), which accounts for the effect of van der Waals forces. In contrast to the Perdew-Burke-Ernzerhof (PBE), revPBE, and other generalized-gradient approximation functionals, the vdW-DF finds that, for most coverages, the adsorption energy of the butterfly structure is greater than that of the tight-bridge structure

Computer simulations studies of the catalytic oxidation of carbon monoxide on platinum metals

The steady‐state catalytic oxidation process of carbon monoxide on platinum metal surfaces is studied using two irreversible kinetic computer simulation models: (a) An extended version of the model introduced by Ziff, Gulari, and Barshad (ZGB) with the effects of CO desorption and diffusion as well as finite reaction probability taken into account. The different physical processes, diffusion and desorption are studied independently and their effect on the equilibrium window, i.e., the regime where steady CO2 formation occurs is determined. (b) An interaction model where adatom–adatom nearest‐neighbor (nn) interactions are taken explicitly into account through Boltzmann terms J 1, J 2, and J 3 which are the energies of the CO–CO, O–O, and CO–O interactions, respectively. The phase diagrams in the temperature–CO‐partial pressure (T,p CO− ) plane are determined for different values of the nn interactions. The behavior of the system is dependent on the sign of J 1(=J 2 in the simulations) as well as the sign of the difference J 1−J 3. There is thus a clear analogy with a two‐component equilibrium lattice gas with nn interactions.Peer reviewe

Paternity, erectile function, and health-related quality of life in patients operated for pediatric testicular torsion

Introduction Spermatic cord torsion (SCT) may lead to organ loss and can potentially influence fertility. Long-term effects of SCT are not fully investigated. Objective The purpose was to evaluate paternity rates in adults who have had SCT in childhood and to compare the results to those of a control population. The secondary purposes were to compare paternity rates after testis-preserving surgery with those after orchiectomy and to evaluate erectile function and health-related quality of life (HRQoL). Study design Questionnaires concerning paternity, erectile function (International Index of Erectile Function [IIEF]-5 questionnaire), and HRQoL (15D questionnaire) were mailed to 74 men who had been treated for SCT and to 92 controls treated for testicular appendage torsion in 1977-1995 and who were currently older than 30 years. Results Thirty-five of the 74 (47%) patients with SCT and 58 of the 92 (63%) controls responded. A same-aged control was selected for each patient with SCT. The median age at investigation was 41 (interquatile range [IQR]: 36 to 46) years in the SCT group and 41 (IQR: 38 to 46) years in the control group (p = 0.81). The paternity rate was 23 of 35 (66%) in the SCT group and 26 of 34 (76%) in the control group (p = 0.43). Nine percent of patients and controls suffered from infertility. Of the 30- to 50-year-old patients with SCT, 9 of 16 (56%) had children after orchiectomy, and 13 of 16 (81%), after detorsion (p = 0.25). Significant or moderate erectile dysfunction (IIEF-5 total score Discussion Paternity, erectile function, or HRQoL was not impaired in the general level in the patients with SCT in comparison with controls. Both the modes of treatment, orchiectomy or detorsion, had no significant impact on the results. However, the results cannot be generalized to the individual level. The limitations were a small sample size and inability to investigate maternal factors to the paternity. However, the results are encouraging for the patients and families. Conclusion Paternity rate and HRQoL were similar in patients with SCT and controls. The type of surgery (orchiectomy vs. detorsion) did not affect paternity rates statistically. Moderate or significant erectile dysfunction was rare in both groups.Peer reviewe

Breast Reconstruction-Prospective Follow up on Breast Cancer Patients' Health-Related Quality of Life

Background Analysing the results of breast reconstruction is important both in terms of oncological safety and health-related quality of life (HRQoL). Immediate breast reconstruction (IBR) is thought to be prone to complications and heavy for patients with no time to adapt to having cancer. Delayed reconstruction (DR) is an option after primary surgery and oncological treatments, but requires patients to go through two recovery periods after surgery. Methods A prospective study of 1065 breast cancer patients with repeated measurement of HRQoL with both generic (15D) and disease specific (EORTC QLQ C-30 BR23) measuring tools included 51 IBR patients and 41 DR patients. These patients' HRQoL and reconstruction methods were studied in more detail alongside with clinical data to determine HRQoL levels for patients with IBR and those with mastectomy and DR during a 24-month follow-up. Measuring points were baseline, 3, 6, 12 and 24 months. Results Most frequent techniques used were abdominal flaps (IBR n = 16, DR n = 14), latissimus dorsi flaps (LD) (IBR n = 19, DR n = 10), implants (IBR n = 12) and fat grafting (DR n = 6). Smaller groups were excluded from group comparisons. Approximately one third of the patients encountered complications. Symptom scores did not differ between reconstruction methods. DR patients had better overall HRQoL at 12 months, but at 24 months the situation had changed in favour of IBR. Both approaches of reconstructive surgery produced good HRQoL with no significant differences between the approaches studied.Peer reviewe