Sökresultat

The oxidation of ammonia is a key reaction for the production of artificial fertilizers and for environmental protection. Depending on the area of application, the catalytic reaction needs to be tuned toward the production of either N2 or NO, and this selectivity is controlled by temperature, pressure, reactant ratio, and the type of catalyst. PtRh alloys are highly useful catalytic materials for

Understanding the emergence and development of coastal adaptations is a central theme in the archaeology of Maritime Northeast Asia. The capacity to harvest, store and share aquatic resources offered a novel economic strategy that could support greater sedentism and new forms of social life. In turn, growing reliance on the exploitation of rich coastal resources wouldhave generated powerful incent

The present study aimed to model reconnaissance drought index (RDI) time series at three various time scales (i.e., RDI-6, RDI-9, RDI-12). Two weather stations located at Iran, namely Tehran and Dezful, were selected as the case study. First, support vector regression (SVR) was utilized as the standalone modeling technique. Then, hybrid models were implemented via coupling the standalone SVR with

Reidite, the high-pressure zircon (ZrSiO4) polymorph, is a diagnostic indicator of impact events. Natural records of reidite are, however, scarce, occurring mainly as micrometer-sized lamellae, granules, and dendrites. Here, we present a unique sequence of shocked zircon grains found within a clast from the Chassenon suevitic breccia (shock stage III) from the ˜200 Ma, 20–50 km wide Rochechouart i

Introduction: Phenylketonuria (PKU) is a rare, treatable inborn error of metabolism with frequent neurological and neuropsychiatric complications, especially in undiagnosed or insufficiently treated individuals. Given the wide range of clinical presentations and the importance of treatment implications, we here delineate the neurological and neuropsychiatric symptom spectrum in a large cohort of p

The present paper argues that if the so-called mindfulness movement is to reach its full potential it needs to emancipate from its religious context and ally itself fully with psychological science. The argument that mindfulness meditation needs a religious context for ethical reasons is untenable. Although mindfulness skills may well be used for un-ethical purposes, this applies equally to both r

Introduction Clinical recommendations for childhood asthma are often based on data extrapolated from studies conducted in adults, despite significant differences in mechanisms and response to treatments. The Paediatric Asthma in Real Life (PeARL) Think Tank aspires to develop recommendations based on the best available evidence from studies in children. An overview of systematic reviews (SRs) on p

The formation path from small poorly absorbing incipient soot to larger fractal-like strongly absorbing black soot is extensive, and along this path the optical and physicochemical properties of the soot evolve. Soot emitted into the atmosphere may originate from some stage of this process, which will result in a wide spectrum of carbonaceous aerosols in the atmosphere which may interact with the

We investigated specific anion binding to basic amino acid residues as well as to a range of patchy protein models. This microscopic information was subsequently used to probe protein–protein interactions for aqueous lysozyme solutions. Using computer simulations to study both atomistic and coarse grained protein molecules, it is shown that the ion–protein interaction mechanism as well as magnitud

Hvorfor skal den vigtige debat om Spotifys indflydelse på musiklytning og musikoplevelse ende som et ufrugtbart møde mellem et personangreb og en forsvarstale? Er Seismografs læsere mon blevet klogere på, hvad Spotifys digitale infrastruktur kan gøre ved brugerens lytteoplevelse? Streaming-forskeren Andreas Helles Pedersen hiver et tredje øre ind i debatten.

We investigate specific anion binding to a range of patchy protein models and use our results to probe protein-protein interactions for aqueous lysozyme solutions. Our molecular simulation studies show that the ion-protein interaction mechanism and strength largely depend on the nature of the interfacial amino acid residues. Via direct ion pairing, small anions interact with charged side-chains wh

Using molecular dynamics simulations in an explicit aqueous solvent, we examine the binding of fluoride versus iodide to a spherical macromolecule with both hydrophobic and positively charged patches. Rationalizing our observations, we divide the ion association interaction into two mechanisms: (1) poorly solvated iodide ions are attracted to hydrophobic surface patches, while (2) the strongly sol

For a series of biologically relevant anions, we present free energy changes upon replacing potassium with sodium in a contact ion pair. Calculations performed using a combination of molecular dynamics simulations and ab initio methods demonstrate the ordering of anions in a Hofmeister series. Small anionic groups such as carboxylates preferentially pair with sodium, while intermediate cases such

Proteins in the living cell can interact with a wide variety of solutes, ranging from ions, peptides, other proteins, DNA to membranes. Charged groups play a major role and solution conditions such as pH and ionic strength can modulate the interactions significantly. Describing these systems in a statistical mechanical framework involves thousands of pair-interactions and therefore a certain amoun

The discovery of high-order harmonic generation (HHG) has made it possible to see the electron dynamics on their natural time scale, attoseconds. In the HHG process, a femtosecond infrared (IR) laser pulse is converted into a train of attosecond pulses in the extreme ultraviolet (XUV), but with a very low conversion efficiency. The low intensity has to be used efficiently and that means keeping th

Many applications of the extreme ultraviolet (XUV) radiation obtained by high-order harmonic generation (HHG) in gases require a small focus area in order to enable attosecond pulses to reach a high intensity. Here, high-order harmonics generated in Ar with a multiterawatt laser system in a loose focusing geometry are focused to a few micrometers using two toroidal mirrors in a Wolter configuratio