ZZ production at high transverse momenta beyond NLO QCD

We study the production of the four-lepton final state $l^+ l^- l^+ l^-$, predominantly produced by a pair of electroweak Z bosons, ZZ. Using the LoopSim method, we merge NLO QCD results for ZZ and ZZ+jet and obtain approximate NNLO predictions for ZZ production. The exact gluon-fusion loop-squared contribution to the ZZ process is also included. On top of that, we add to our merged sample the gluon-fusion ZZ+jet contributions from the gluon-gluon channel, which is formally of N^3LO and provides approximate results at NLO for the gluon-fusion mechanism. The predictions are obtained with the VBFNLO package and include the leptonic decays of the Z bosons with all off-shell and spin-correlation effects, as well as virtual photon contributions. We compare our predictions with existing results for the total inclusive cross section at NNLO and find a very good agreement. Then, we present results for differential distributions for two experimental setups, one used in searches for anomalous triple gauge boson couplings, the other in Higgs analyses in the four charged-lepton final state channel. We find that the approximate NNLO corrections are large, reaching up to 20% at high transverse momentum of the Z boson or the leading lepton, and are not covered by the NLO scale uncertainties. Distributions of the four-lepton invariant mass are, however, stable with respect to QCD corrections at this order.Comment: 21 pages, 2 tables, 9 figure

Measuring Hidden Higgs and Strongly-Interacting Higgs Scenarios

Higgs couplings can be affected by physics beyond the Standard Model. We study modifications through interactions with a hidden sector and in specific composite Higgs models accessible at the LHC. Both scenarios give rise to congruent patterns of universal, or partially universal, shifts. In addition, Higgs decays to the hidden sector may lead to invisible decay modes which we also exploit. Experimental bounds on such potential modifications will measure the concordance of an observed Higgs boson with the Standard Model.Comment: 12 pages, 7 figures; version to be published in Phys. Lett.

Entwicklung von funktionellen Polymerbürsten mit modularen Eigenschaften

Im Rahmen dieser Arbeit wurden neuartige, temperatursensitive Polymerbürsten mit terminaler Click-Funktionalität hergestellt, die nicht nur im Detail untersucht bzw. charakterisiert wurden, sondern deren Eigenschaften zusätzlich durch die polymeranaloge Umsetzung mit einem entsprechend modifizierten Fluoreszenzfarbstoff, Polymer oder mit superparamagnetischen Nanopartikeln erweitert werden konnten. Mittels kontrolliert radikalischer Polymerisation wurde mono- und bi-funktionalisiertes Poly(N-isopropylacrylamid) mit unterschiedlichen Endgruppen und Molekulargewichten synthetisiert und über das "grafting to"-Verfahren an eine Modeloberfläche angebunden. Die kovalente Anbindung der entsprechenden Komponenten erfolgte entweder durch die Kupfer-katalysierte oder thermisch induzierte Alkin-Azid-Cycloaddition. Neben den physiko-chemischen Eigenschaften wurde im Besonderen das temperaturabhängige Schaltverhalten dieser funktionellen Polymerbürsten in situ untersucht, wobei neben der spektroskopischen Ellipsometrie als Hauptmethode, zusätzlich Rasterkraftmikroskopie, UV/VIS- und Fluoreszenzspektroskopie, sowie Elektronenmikroskopie verwendet wurden. Im Fall der Farbstoff-modifizierten Polymerbürsten zeigte sich, dass nicht nur die Eigenschaften des Farbstoffs durch das Polymer beeinflussbar sind, sondern auch das Quellverhalten der Polymerbürsten durch den Farbstoff. Die mit Nanopartikeln modifizierten Polymerbürsten zeigten eine homogene Verteilung der Partikel auf der Oberfläche, sowie eine veränderte Schaltcharakteristik, die durch das Auftreten eine dynamischen Wechselwirkungszone zwischen den Polymerbürsten und den Nanopartikeln erklärt werden kann. Mit Hilfe der thermisch induzierten Azid-Alkin-Cycloaddition konnten erstmalig definierte Kettenverlängerungen an Polymerbürsten durchgeführt und gleichzeitig der Nachteil der limitierten Pfropfungsdichte der „grafting to“-Methode überwunden werden. Darüber hinaus konnte der temperaturinduzierte Schalteffekt nicht nur erhalten bleiben, sondern in Bezug auf die Schaltamplitude auch signifikant vergrößert werden und ergab ein sensitiveres, verbessertes Polymerbürstensystem

Surface modification of silicon nanowire based field effect transistors with stimuli responsive polymer brushes for biosensing applications

We demonstrate the functionalization of silicon nanowire based field effect transistors (SiNW FETs) FETs with stimuli-responsive polymer brushes of poly(N-isopropylacrylamide) (PNIPAAM) and poly(acrylic acid) (PAA). Surface functionalization was confirmed by atomic force microscopy, contact angle measurements, and verified electrically using a silicon nanowire based field effect transistor sensor device. For thermo-responsive PNIPAAM, the physicochemical properties (i.e., a reversible phase transition, wettability) were induced by crossing the lower critical solution temperature (LCST) of about 32 C. Taking advantage of this property, osteosarcomic SaoS-2 cells were cultured on PNIPAAM-modified sensors at temperatures above the LCST, and completely detached by simply cooling. Next, the weak polyelectrolyte PAA, that is sensitive towards alteration of pH and ionic strength, was used to cover the silicon nanowire based device. Here, the increase of pH will cause deprotonation of the present carboxylic (COOH) groups along the chains into negatively charged COO- moieties that repel each other and cause swelling of the polymer. Our experimental results suggest that this functionalization enhances the pH sensitivity of the SiNW FETs. Specific receptor (bio-)molecules can be added to the polymer brushes by simple click chemistry so that functionality of the brush layer can be tuned optionally. We demonstrate at the proof-of concept-level that osteosarcomic Saos-2 cells can adhere to PNIPAAM-modified FETs, and cell signals could be recorded electrically. This study presents an applicable route for the modification of highly sensitive, versatile FETs that can be applied for detection of a variety of biological analytes. © 2020 by the authors

Polyoxymethylene as Material for Removable Partial Dentures—A Literature Review and Illustrating Case Report

Compared to thermoplastic manufacturing techniques, computer-aided design (CAD) and computer-aided manufacturing (CAM) technologies make it easier to process modern restorative and prosthetic materials with improved material properties. In dentistry, tooth-colored alternatives to metal-based frameworks for application in removable dental prostheses (RDP) emerged. With regard to this aspect, the current article provides an overview of the specific material properties of polyoxymethylene (POM). Furthermore, it reviews scientific literature indexed in PubMed and Web of Science that focuses on RDPs fabricated from POM within the last 10 years. Finally, a prosthetic rehabilitation of a patient with a RDP fabricated from POM is illustrated and observations during a follow-up over 10 months are described. Scientific data and clinical observations indicate that polyoxymethylene is a promising material that bridges gaps in dental therapeutic options. While survival time may be limited due to wear, POM might be a favorable option for application in semi-permanent restorations

Equivalence of care? Accessibility and availability of dialysis services for older prisoners in Switzerland

Purpose: According to the principle of equivalence of care, health care in prison has to be of the same standard and quality as in the general population. This study aims to determine the geographic accessibility of dialysis services for older prisoners and the older general population in Switzerland and whether accessibility and availability of dialysis care are equivalent. Design/methodology/approach: Spatial accessibility analysis incorporated four different data types: population data, administrative data, street network data and addresses of prisons and hemodialysis services. Findings: Analysis revealed that the average travel time to the nearest dialysis service was better for prisoners (11.5 min) than for the general population (14.8 min). However, dialysis service for prisoners is hampered by the necessary lead-time in correctional settings, which, ultimately, leads to longer overall access times (36.5 min). Accordingly, the equivalence of dialysis care for older Swiss prisoners is not entirely respected for availability and accessibility. Originality/value: The strength of the study lies in the combination of ethical principles and the highly tangible results of a spatial accessibility analysis. The ethics-driven empirical analysis provides arguments for policy-makers to review the current practices

Tooth-Colored CAD/CAM Materials for Application in 3-Unit Fixed Dental Prostheses in the Molar Area: An Illustrated Clinical Comparison

The aim of this study was to compare the clinical properties of tooth-colored computer-aided design/computer-aided manufacturing (CAD/CAM) materials for the fabrication of a 3-unit fixed dental prostheses (FDPs) in the same clinical scenario. A 53-year-old female patient was supplied with a 3-unit FDP to replace a second premolar in the upper jaw. Restorations were fabricated from 3 mol%, 4 mol%, and 5 mol% yttrium oxide zirconia, zirconia with translucency gradient, indirect composite resin, polyetheretherketone (PEEK), and polyetherketoneketone (PEKK). Milling time, weight, and radiopacity were investigated. Esthetics were examined following the US Public Health Service criteria (USPHS). The milling time for zirconia was twice as high as for the indirect composite resin, PEEK, or PEKK. The latter materials had a weight of 2 g each, while zirconia restorations yielded 5 g. Zirconia presented intense radiopacity. PEEK and PEKK required veneering and an opaquer was applied to the PEKK framework. All FDPs showed acceptable esthetics. PEEK and PEKK restorations were featured by a grayish shimmering. A variety of CAD/CAM materials are available to fabricate 3-unit FDPs with esthetically acceptable results. In the esthetic zone, PEEK and PEKK require veneering and an opaquer might be applied. Milling time, weight, and radiopacity were relatively high for zirconia FDPs

Utilization of dental services and health literacy by older seniors during the COVID-19 pandemic

Background: This study aimed to investigate the utilization of dental services by older seniors during the COVID-19 pandemic and to evaluate their ability of finding, understanding, and using information on COVID-19. Methods: At the end of February 2021, a survey addressing demographic characteristics of the participants, (pain-associated) utilization of dental services, worries regarding a potential COVID-19 infection, the individual use of protective masks, and difficulties regarding the access to information on COVID-19 (by using the modified European Health Literacy Questionnaire [HLS-EU-Q16]) was developed. It was sent to all patients of the Dental Clinic of University of Leipzig who were either 75, 80, or 85 years old (n = 1228). Participation was voluntarily and anonymously; questionnaires had to be returned within six weeks, no reminders were sent. Results: Of the 439 replies (response rate 35.7%), twelve were excluded from data extraction due to disinterest, dementia, or lack of age information. Of the older seniors, 81.5% (n = 348) had utilized at least one dental examination and 54.2% of the dentulous patients (n = 199) had attended at least one dental hygiene appointment within the past year. Up to 55.8% of all participants said it was "difficult" or "very difficult" to find, understand, and use information on COVID-19, especially when judging reliability of information presented in the media, which was especially true for seniors with assigned care levels presenting odds ratios up to 5.30. Conclusions: The investigation revealed a frequent utilization of dental services by older seniors during the COVID-19 pandemic. However, the older seniors encountered difficulties finding, using, and understanding information about COVID-19. Keywords: COVID-19; geriatric dentistry; gerodontology; health literacy; older seniors; utilization