On-surface Assembly of Au-Dicyanoanthracene Coordination Structures on Au(111)

On-surface metal-organic coordination provides a promising way for synthesizing different two-dimensional lattice structures that have been predicted to possess exotic electronic properties. Using scanning tunneling microscopy (STM) and spectroscopy (STS), we studied the supramolecular self-assembly of 9,10-dicyanoanthracene (DCA) molecules on the Au(111) surface. Close-packed islands of DCA molecules and Au-DCA metal-organic coordination structures coexist on the Au(111) surface. Ordered DCA$_{3}$Au$_{2}$ metal-organic networks have a structure combining a honeycomb lattice of Au atoms with a kagome lattice of DCA molecules. Low-temperature STS experiments demonstrate the presence of a delocalized electronic state containing contributions from both the gold atom states and the lowest unoccupied molecular orbital of the DCA molecules. These findings are important for the future search of topological phases in metal-organic networks combining honeycomb and kagome lattices with strong spin-orbit coupling in heavy metal atoms

Pain induced by propofol - clinical studies on drug composition and adminstration

Over the last 25 years a number of new anaesthetic drugs have been introduced on the market to allow for better patient satisfaction and faster recovery after anaesthesia and sedation. Propofol (2,6-di-isopropylphenol), one of our most common iv anaesthetics, is associated with pleasant sleep and rapid recovery with little postoperative nausea. When used for anaesthetic induction propofol causes severe or even intolerable pain or discomfort on injection in up to 90 % of patients. Pain on injection of propofol is even ranked by anaesthesiologists as the seventh most important clinical problem in modern anaesthesia. The concentration of free propofol within the aqueous phase of the drug formula is believed to be particularly associated with injection pain. The general aim of these studies was to investigate if we could reduce the local pain induced by iv propofol by various clinical measures. Traditional long-chain triglyceride (LCT) emulsions of propofol were used in studies I-III, while a new medium- and long-chain triglyceride (MCT/LCT) formula was used in studies III-V. Both formulas were used and compared in study III. In study I the influence of a carrier fluid was evaluated. Simultaneous iv infusion of carrier fluid was found not to influence pain intensity but to decrease the duration of pain at the site of propofol injection. In study II we investigated the effect of various bolus rates of propofol on pain at site of injection. There were no differences in the incidence, intensity or duration of pain between the faster and slower rates compared. In study III we compared the influence of two different formulas of propofol on local pain at the site of administration. Propofol emulsions based on MCT/LCT were associated with lower pain intensity than those based on LCT only. Study IV was designed to examine if local venous occlusion applied during and immediately after injection of propofol reduces the intensity of pain at the site of injection. Venous occlusion was found to increase the intensity but not the duration of pain at the site of propofol injection, indicating that the pain response to propofol fades during prolonged intravascular exposure. Study V was carried out to examine if pain on injection of propofol can be reduced by previous low-dose administration of propofol by the same iv route. A lower incidence of moderate or severe local pain was induced by propofol after the low dose of propofol had been administered. Our most important results show that formulas of propofol based on MCT/LCT are associated with less pain at the site of iv injection than are traditional LCT formulas. Furthermore the incidence of moderate to severe propofol-induced pain can be reduced by previous injection of a low dose of propofol by the same iv route. These measures can easily be taken by any anaesthetist in virtually any clinical situation not calling for rapid induction of anaesthesia

Two-dimensional band structure in honeycomb metal-organic frameworks

Metal-organic frameworks (MOFs) are an important class of materials that present intriguing opportunities in the fields of sensing, gas storage, catalysis, and optoelectronics. Very recently, two-dimensional (2D) MOFs have been proposed as a flexible material platform for realizing exotic quantum phases including topological and anomalous quantum Hall insulators. Experimentally, direct synthesis of 2D MOFs has been essentially confined to metal substrates, where the interaction with the substrate masks the intrinsic electronic properties of the MOF. Here, we demonstrate synthesis of 2D honeycomb metal-organic frameworks on a weakly interacting epitaxial graphene substrate. Using low-temperature scanning tunneling microscopy (STM) and atomic force microscopy (AFM) complemented by density-functional theory (DFT) calculations, we show the formation of 2D band structure in the MOF decoupled from the substrate. These results open the experimental path towards MOF-based designer quantum materials with complex, engineered electronic structures

Topographic and electronic contrast of the graphene moir\'e on Ir(111) probed by scanning tunneling microscopy and non-contact atomic force microscopy

Epitaxial graphene grown on transition metal surfaces typically exhibits a moir\'e pattern due to the lattice mismatch between graphene and the underlying metal surface. We use both scanning tunneling microscopy (STM) and atomic force microscopy (AFM) experiments to probe the electronic and topographic contrast of the graphene moir\'e on the Ir(111) surface. While STM topography is influenced by the local density of states close to the Fermi energy and the local tunneling barrier height, AFM is capable of yielding the 'true' surface topography once the background force arising from the van der Waals (vdW) interaction between the tip and the substrate is taken into account. We observe a moir\'e corrugation of 35$\pm$10 pm, where the graphene-Ir(111) distance is the smallest in the areas where the graphene honeycomb is atop the underlying iridium atoms and larger on the fcc or hcp threefold hollow sites.Comment: revised versio

Is physical activity a pathway to culturally and linguistically diverse children’s participation in early childhood education and care?

The Finnish early childhood education’s main principle is to guarantee all children’s and families' rights, prevent segregation, and enhance equality, inclusion, diversity, participation, and communality. Physical activities are one significant way to support all children’s well-being and participation. According to previous studies physical activities were also connected to participation among culturally and linguistically diverse children (Arvola, 2021; Arvola et al., 2020). The study aims to find out if physical activity is a pathway to culturally and linguistically diverse children’s participation. This study is a part of the large Progressive Feedback research results gathered in Finland (see https://blogs.helsinki.fi/orientate/). The main method of the study is systematic observation. According to these results, culturally and linguistically diverse children move enough during their day care day, but they were more often interrupted, less involved, and less participative in their activities. Physical activity was related to continuous involvement. The most increasing physical activity was in sustaining intense involvement: a third of all movement happened in high involvement. The observation results indicate that physical activity is related to increased involvement and building social processes among culturally and linguistically diverse children.

Propofol infusion rate does not affect local pain on injection.

BACKGROUND: Local pain at the site of an i.v. injection of propofol is a well-known problem, particularly in infants. This randomised investigator-blinded crossover study was designed to assess the effect of the i.v. bolus infusion rate on propofol-induced pain at the site of injection. METHODS: Thirty unpremedicated patients scheduled for ear-nose-throat or plastic surgery at Malmö University Hospital, Sweden, were given two consecutive 2.0 ml injections of propofol 10 mg/ml (Diprivan, AstraZeneca, Sweden/UK), at different infusion rates (0.2 or 1.0 ml/s), immediately before induction of general anesthesia. Half of the patients (n=15) received the first bolus of propofol over 2 s and the second bolus over 10 s, and the other half (n=15) had their injections in reversed order. After each injection, the patient was asked by an investigator to indicate pain intensity on a visual analog scale (VAS) and to report the times of the appearance, maximum point and disappearance of pain. The injections were given approximately 2 min apart. The investigators scoring pain intensity, as indicated by the patients on a 10-point numerical rate scale, were blinded to the order in which the injections were given, as were the patients themselves. RESULTS: There were no statistically significant differences in the incidence (both 86%) of intensity (median; 25th; 75th percentiles, in VAS units: 3.1; 1.0; 5.3 and 3.3; 1.4; 5.0, respectively) or duration (66+/-31 and 73+/-26 s, respectively) of pain between the faster (1.0 ml/s) and slower (0.2 ml/s) bolus infusion rates of propofol studied. CONCLUSIONS: We conclude that the i.v. bolus infusion rate of propofol does not influence drug-induced local pain on injection, at least not within the infusion rate interval studied. Therefore, adjusting i.v. injection speed does not seem to be a clinically useful tool for reducing the intensity or duration of propofol-induced pain at the site of administration

Benchmarking van der Waals-treated DFT: The case of hexagonal boron nitride and graphene on Ir(111)

There is enormous recent interest in weak, van der Waals-type (vdW) interactions due to their fundamental relevance for two-dimensional materials and the so-called vdW heterostructures. Tackling this problem using computer simulation is very challenging due to the non-trivial, non-local nature of these interactions. We benchmark different treatments of London dispersion forces within the density functional theory (DFT) framework on hexagonal boron nitride or graphene monolayers on Ir(111) by comparing the calculated geometries to a comprehensive set of experimental data. The geometry of these systems crucially depends on the interplay between vdW interactions and wave function hybridisation, making them excellent test cases for vdW-treated DFT. Our results show strong variations in the calculated atomic geometry. While some of the approximations reproduce the experimental structure, this is rather based on \textit{a posteriori} comparison with the ``target results''. General predictive power in vdW-treated DFT is not achieved yet and might require new approaches.Comment: More or less published version, with Supporting Materia

Elastic properties of 2D auxetic honeycomb structures- a review

The research field of auxetics, materials or structures exhibiting a negative Poisson's ratio, has received attention because of the unusually advantageous material properties that can be achieved with it, such as high indentation resistance and high shear resistance. In the past decades, the theoretical understanding of different factors that can lead to an auxetic behaviour has advanced greatly, resulting in a rapid increase in the number and type of the structures designed to exhibit this behaviour. These now exploit a number of different mechanisms, providing a large selection of properties which can be tailored for the specific needs. This review aims to describes the auxetic structures that have currently been identified and designed, describing the different approaches utilised to define their mechanical behaviour and analysing their structural properties, limitations, and potential field of application. In particular, the focus lies on the major works within the field, discussing their limitations and addressing works done to complement them