SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Baran R) "

Sökning: WFRF:(Baran R)

  • Resultat 1-42 av 42
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Lind, Lars, et al. (författare)
  • Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)
  • 2021
  • Ingår i: eLife. - : eLife Sciences Publications Ltd. - 2050-084X. ; 10
  • Tidskriftsartikel (refereegranskat)abstract
    • From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions.
  •  
2.
  • Mishra, A, et al. (författare)
  • Diminishing benefits of urban living for children and adolescents' growth and development
  • 2023
  • Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 615:7954, s. 874-883
  • Tidskriftsartikel (refereegranskat)abstract
    • Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified.
  •  
3.
  •  
4.
  •  
5.
  •  
6.
  •  
7.
  •  
8.
  •  
9.
  • Mansouri, L, et al. (författare)
  • Different prognostic impact of recurrent gene mutations in chronic lymphocytic leukemia depending on IGHV gene somatic hypermutation status: a study by ERIC in HARMONY
  • 2023
  • Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 37:2, s. 339-347
  • Tidskriftsartikel (refereegranskat)abstract
    • Recent evidence suggests that the prognostic impact of gene mutations in patients with chronic lymphocytic leukemia (CLL) may differ depending on the immunoglobulin heavy variable (IGHV) gene somatic hypermutation (SHM) status. In this study, we assessed the impact of nine recurrently mutated genes (BIRC3, EGR2, MYD88, NFKBIE, NOTCH1, POT1, SF3B1, TP53, and XPO1) in pre-treatment samples from 4580 patients with CLL, using time-to-first-treatment (TTFT) as the primary end-point in relation to IGHV gene SHM status. Mutations were detected in 1588 (34.7%) patients at frequencies ranging from 2.3–9.8% with mutations in NOTCH1 being the most frequent. In both univariate and multivariate analyses, mutations in all genes except MYD88 were associated with a significantly shorter TTFT. In multivariate analysis of Binet stage A patients, performed separately for IGHV-mutated (M-CLL) and unmutated CLL (U-CLL), a different spectrum of gene alterations independently predicted short TTFT within the two subgroups. While SF3B1 and XPO1 mutations were independent prognostic variables in both U-CLL and M-CLL, TP53, BIRC3 and EGR2 aberrations were significant predictors only in U-CLL, and NOTCH1 and NFKBIE only in M-CLL. Our findings underscore the need for a compartmentalized approach to identify high-risk patients, particularly among M-CLL patients, with potential implications for stratified management.
  •  
10.
  •  
11.
  •  
12.
  • Almora, Osbel, et al. (författare)
  • Device Performance of Emerging Photovoltaic Materials (Version 1)
  • 2020
  • Ingår i: Advanced Energy Materials. - : Wiley. - 1614-6832 .- 1614-6840. ; 11:11
  • Tidskriftsartikel (refereegranskat)abstract
    • Emerging photovoltaics (PVs) focus on a variety of applications complementing large scale electricity generation. Organic, dye-sensitized, and some perovskite solar cells are considered in building integration, greenhouses, wearable, and indoor applications, thereby motivating research on flexible, transparent, semitransparent, and multi-junction PVs. Nevertheless, it can be very time consuming to find or develop an up-to-date overview of the state-of-the-art performance for these systems and applications. Two important resources for recording research cells efficiencies are the National Renewable Energy Laboratory chart and the efficiency tables compiled biannually by Martin Green and colleagues. Both publications provide an effective coverage over the established technologies, bridging research and industry. An alternative approach is proposed here summarizing the best reports in the diverse research subjects for emerging PVs. Best performance parameters are provided as a function of the photovoltaic bandgap energy for each technology and application, and are put into perspective using, e.g., the Shockley–Queisser limit. In all cases, the reported data correspond to published and/or properly described certified results, with enough details provided for prospective data reproduction. Additionally, the stability test energy yield is included as an analysis parameter among state-of-the-art emerging PVs.
  •  
13.
  • Baran, J. D., et al. (författare)
  • Theoretical and experimental comparison of SnPc, PbPc, and CoPc adsorption on Ag(111)
  • 2010
  • Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121 .- 1550-235X. ; 81:7
  • Tidskriftsartikel (refereegranskat)abstract
    • A combination of normal-incidence x-ray standing-wave (NIXSW) spectroscopy, x-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and density-functional theory (DFT) has been used to investigate the interaction of a number of phthalocyanine molecules (specifically, SnPc, PbPc, and CoPc) with the Ag(111) surface. The metal-surface distances predicted by the DFT calculations for SnPc/Ag(111) (2.48 angstrom) and CoPc/Ag(111) (2.88 angstrom) are in good agreement with our NIXSW experimental results for these systems (2.31 +/- 0.09 and 2.90 +/- 0.05 angstrom, respectively). Good agreement is also found between calculated partial density-of-states plots and STM images of CoPc on Ag(111). Although the DFT and Pb 4f NIXSW results for the Pb-Ag(111) distance are similarly in apparently good agreement, the Pb 4f core-level data suggest that a chemical reaction between PbPc and Ag(111) occurs due to the annealing procedure used in our experiments and that the similarity of the DFT and Pb 4f NIXSW values for the Pb-Ag(111) distance is likely to be fortuitous. We interpret the Pb 4f XPS data as indicating that the Pb atom can detach from the PbPc molecule when it is adsorbed in the "Pb-down" position, leading to the formation of a Pb-Ag alloy and the concomitant reduction in Pb from a Pb2+ state (in bulklike films of PbPc) to Pb-0. In contrast to SnPc, neither PbPc nor CoPc forms a well-ordered monolayer on Ag(111) via the deposition and annealing procedures we have used. Our DFT calculations show that each of the phthalocyanine molecules donate charge to the silver surface, and that back donation from Ag to the metal atom (Co, Sn, or Pb) is only significant for CoPc.
  •  
14.
  • Baran, R., et al. (författare)
  • A multicentre, randomized, controlled study of the efficacy, safety and cost-effectiveness of a combination therapy with amorolfine nail lacquer and oral terbinafine compared with oral terbinafine alone for the treatment of onychomycosis with matrix involvement
  • 2007
  • Ingår i: Br J Dermatol. ; 157:1, s. 149-57
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Onychomycosis is common, accounting for up to 50% of all nail disorders. Toenail onychomycosis can cause nail deformity, embarrassment, pain and walking difficulties. Some populations, such as individuals with diabetes, are at higher risk for developing secondary complications such as infections. Treatment takes many months and therapeutic choices can increase clinical effectiveness, lower toxicity and minimize healthcare costs. OBJECTIVES: Based on the results of a previous pilot study, the objective of the present study was to show, in a larger population, the enhanced efficacy of a combination of amorolfine nail lacquer and oral terbinafine in the treatment of onychomycosis with matrix involvement. In addition, a cost-effectiveness analysis was performed. METHODS: In this multicentre, randomized, open-label, parallel group study, patients were randomized to receive either a combination of amorolfine hydrochloride 5% nail lacquer once weekly for 12 months plus terbinafine 250 mg once daily for 3 months (AT group) or terbinafine alone once daily for 3 months (T group). The study duration was 18 months including a 6-month treatment-free phase following the 12-month active treatment phase for the AT group and a 15-month treatment-free phase following the 3-month active treatment phase for the T group. The primary efficacy criterion was overall response, dichotomized into success or failure, success being the combination of clinical cure and negative mycology at month 18. This criterion was used as the effectiveness measure in the pharmacoeconomic analysis, conducted from a payer perspective. RESULTS: In total, 249 patients were included into the study: 120 in the AT group and 129 in the T group. A significantly higher success rate was observed for patients in the AT group relative to those in the T group at 18 months (59.2% vs. 45.0%; P = 0.03). Both treatment regimens were safe and well tolerated. Treatment cost per cured patient was lower for the combination than for terbinafine alone in all countries. CONCLUSIONS: Study results confirmed that, in the treatment of dermatophytic toenail onychomycosis with matrix involvement, amorolfine nail lacquer in combination with oral terbinafine enhances clinical efficacy and is more cost-effective than terbinafine alone.
  •  
15.
  • Eren, Baran, et al. (författare)
  • Contamination Issues in Ambient Pressure Experiments
  • 2021
  • Ingår i: Ambient Pressure Spectroscopy in Complex Chemical Environments. - Washington, DC : American Chemical Society. - 0097-6156 .- 1947-5918. - 9780841298125 - 9780841298118 ; 1396, s. 267-295
  • Bokkapitel (refereegranskat)abstract
    • Contamination is the most common and arguably the most significant problem scientists are facing in experimental surface science research that is practiced in the presence of gases. It is fair to say that contamination problems are often worse with ambient pressures compared to conventional experiments in vacuum. It is one of the main reasons for poor reproducibility in this field and in relevant basic and applied research fields like heterogeneous catalysis and electrochemistry. Whilst some type of contaminants are more innocent and only hinder quantitative analysis, some are harmful as they change the outcome of the experiments. In this chapter, the potential sources of contamination are summarized and some solutions are suggested. Examples of commonly observed contaminants such as hydrocarbons, oxygenated hydrocarbons, and adsorbed species of traces gases are presented. The scope of this chapter is restricted to ambient pressure x-ray photoelectron spectroscopy and infrared reflection absorption spectroscopy studies on single crystal surfaces, but similar problems exist on other sample surfaces or with other techniques such as x-ray absorption spectroscopy and sum frequency generation spectroscopy.
  •  
16.
  • Jones, Geraint H., et al. (författare)
  • The Comet Interceptor Mission
  • 2024
  • Ingår i: Space Science Reviews. - : Springer Nature. - 0038-6308 .- 1572-9672. ; 220:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA’s F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum Δ V capability of 600 ms − 1 . Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes – B1, provided by the Japanese space agency, JAXA, and B2 – that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission’s science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule.
  •  
17.
  •  
18.
  •  
19.
  •  
20.
  •  
21.
  •  
22.
  • Babonas, G. J., et al. (författare)
  • Optical properties of Fe-doped silica films on Si
  • 2006
  • Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 252:15, s. 5391-5394
  • Tidskriftsartikel (refereegranskat)abstract
    • Optical properties of Fe-doped silica films on Si were investigated by ellipsometric technique in the region 1-5 eV. Samples were produced by sol-gel method. Precursors were prepared by mixing tetraethoxysilane (TEOS) solution in ethanol and water with aqueous solution of Fe-chloride or Fe-acetate. The coating solution was deposited on Si substrates by spin on technique. The size of Fe-containing nanometric-sized particles depended on technology and varied from 20 to 100 nm. Optical response of complex hybrid samples SiO2:Fe/Si was interpreted in a multi-layer model. In the inverse problem, the Maxwell equations were solved by transfer matrix technique. Dielectric function of Fe-doped silica layers was calculated in the model of effective media. Analysis of optical data has shown that various Fe-oxides formed. Experimental data for films obtained from precursors with Fe-acetate and annealed in hydrogen were well described by the model calculations taking into account a small contribution 1-5% of metal Fe imbedded in silica. The Fe/Fe-O contribution to optical response increased for samples grown from FeCl3-precursor. Ellipsometric data for Fe-doped silica films on Si were interpreted taking into account the structural AFM studies as well as the results of magnetic measurements.
  •  
23.
  • Baran, Jakub D., et al. (författare)
  • A Case of Unusually Large Density of States Changes For Physisorption - TetraPhenyl-Porphyrins on Cu(111)
  • 2015
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Conformational changes caused by surface adsorption can dramatically affect a molecule’s properties. The conformational flexibility of the porphyrin family of molecules has been exploited particularly well in a number of contexts, including prototypical molecular switches. Despite this level of study, however, the exact mechanisms underpinning conformational switching are often unclear. We show that the conformation of the tetra(4-bromophenyl) porphyrin (Br4TPP) on Cu(111) depends critically on the precise adsorption site of the molecule, and that, remarkably, large conformational changes are driven entirely by van der Waals (vdW) interactions between the molecule and the substrate surface. A combination of scanning probe microscopy, low temperature single molecule manipulation, dispersion-corrected density functional theory (DFT) and molecular dynamics (MD) simulations shows that van der Waals forces dominate the adsorption of TPP molecules, causing significant distortions of the molecular architecture so that the porphyrin can adopt one of two low energy conformations. In addition, scanning probe manipulation has been used to translate and switch the Br4TPP molecule between conformations via an intermediary, ‘hybrid’ structure. We have used the generalized gradient approximation (GGA) parameterization by Perdew—Burke—Ernzerhof (PBE), and the sparse-matter optBP86b-vdW20 (vdW-DFT) exchange and correlation functional to account for the missing dispersion forces. In order to check for the presence of chemical bonding we have analyzed the molecule-surface complexes using electron localization function (ELF) and Bader charges. We find that vdW-forces alone are capable of causing large shifts in the molecular density of states, despite the complete absence of chemical interactions.
  •  
24.
  • Baran, R, et al. (författare)
  • Photoonycholysis.
  • 2002
  • Ingår i: Photodermatol Photoimmunol Photomed.. ; 18, s. 202-
  • Tidskriftsartikel (refereegranskat)
  •  
25.
  • Brem, Jürgen, et al. (författare)
  • Imitation of β-lactam binding enables broad-spectrum metallo-β-lactamase inhibitors
  • 2022
  • Ingår i: Nature Chemistry. - : Springer Nature. - 1755-4330 .- 1755-4349. ; 14:1, s. 15-24
  • Tidskriftsartikel (refereegranskat)abstract
    • Carbapenems are vital antibiotics, but their efficacy is increasingly compromised by metallo-β-lactamases (MBLs). Here we report the discovery and optimization of potent broad-spectrum MBL inhibitors. A high-throughput screen for NDM-1 inhibitors identified indole-2-carboxylates (InCs) as potential β-lactamase stable β-lactam mimics. Subsequent structure-activity relationship studies revealed InCs as a new class of potent MBL inhibitor, active against all MBL classes of major clinical relevance. Crystallographic studies revealed a binding mode of the InCs to MBLs that, in some regards, mimics that predicted for intact carbapenems, including with respect to maintenance of the Zn(II)-bound hydroxyl, and in other regards mimics binding observed in MBL-carbapenem product complexes. InCs restore carbapenem activity against multiple drug-resistant Gram-negative bacteria and have a low frequency of resistance. InCs also have a good in vivo safety profile, and when combined with meropenem show a strong in vivo efficacy in peritonitis and thigh mouse infection models.
  •  
26.
  • Castillejo, P., et al. (författare)
  • The AFarCloud ECSEL Project
  • 2019
  • Ingår i: Proceedings - Euromicro Conference on Digital System Design, DSD 2019. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728128610 ; , s. 414-419
  • Konferensbidrag (refereegranskat)abstract
    • Farming is facing many economic challenges in terms of productivity and cost-effectiveness. Labor shortage partly due to depopulation of rural areas, especially in Europe, is another challenge. Domain specific problems such as accurate identification and proper quantification of pathogens affecting plant and animal health are key factors for minimizing economical risks, and not risking human health. The ECSEL AFarCloud (Aggregate FARming in the CLOUD) project will provide a distributed platform for autonomous farming that will allow the integration and cooperation of agriculture Cyber Physical Systems in real-time in order to increase efficiency, productivity, animal health, food quality and reduce farm labour costs. This platform will be integrated with farm management software and will support monitoring and decision-making solutions based on big data and real-time data mining techniques.
  •  
27.
  • Dumanski, Jan P., et al. (författare)
  • Immune cells lacking Y chromosome show dysregulation of autosomal gene expression
  • 2021
  • Ingår i: Cellular and Molecular Life Sciences (CMLS). - : Springer. - 1420-682X .- 1420-9071. ; 78:8, s. 4019-4033
  • Tidskriftsartikel (refereegranskat)abstract
    • Epidemiological investigations show that mosaic loss of chromosome Y (LOY) in leukocytes is associated with earlier mortality and morbidity from many diseases in men. LOY is the most common acquired mutation and is associated with aberrant clonal expansion of cells, yet it remains unclear whether this mosaicism exerts a direct physiological effect. We studied DNA and RNA from leukocytes in sorted- and single-cells in vivo and in vitro. DNA analyses of sorted cells showed that men diagnosed with Alzheimer’s disease was primarily affected with LOY in NK cells whereas prostate cancer patients more frequently displayed LOY in CD4 + T cells and granulocytes. Moreover, bulk and single-cell RNA sequencing in leukocytes allowed scoring of LOY from mRNA data and confirmed considerable variation in the rate of LOY across individuals and cell types. LOY-associated transcriptional effect (LATE) was observed in ~ 500 autosomal genes showing dysregulation in leukocytes with LOY. The fraction of LATE genes within specific cell types was substantially larger than the fraction of LATE genes shared between different subsets of leukocytes, suggesting that LOY might have pleiotropic effects. LATE genes are involved in immune functions but also encode proteins with roles in other diverse biological processes. Our findings highlight a surprisingly broad role for chromosome Y, challenging the view of it as a “genetic wasteland”, and support the hypothesis that altered immune function in leukocytes could be a mechanism linking LOY to increased risk for disease.
  •  
28.
  • Fox, Stuart, et al. (författare)
  • Airborne validation of radiative transfer modelling of ice clouds at millimetre and sub-millimetre wavelengths
  • 2019
  • Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 12:3, s. 1599-1617
  • Tidskriftsartikel (refereegranskat)abstract
    • The next generation of European polar orbiting weather satellites will carry a novel instrument, the Ice Cloud Imager (ICI), which uses passive observations between 183 and 664 GHz to make daily global observations of cloud ice. Successful use of these observations requires accurate modelling of cloud ice scattering, and this study uses airborne observations from two flights of the Facility for Airborne Atmospheric Measurements (FAAM) BAe 146 research aircraft to validate radiative transfer simulations of cirrus clouds at frequencies between 325 and 664 GHz using the Atmospheric Radiative Transfer Simulator (ARTS) and a state-of-the-art database of cloud ice optical properties. Particular care is taken to ensure that the inputs to the radiative transfer model are representative of the true atmospheric state by combining both remote-sensing and in situ observations of the same clouds to create realistic vertical profiles of cloud properties that are consistent with both observed particle size distributions and bulk ice mass. The simulations are compared to measurements from the International Submillimetre Airborne Radiometer (ISMAR), which is an airborne demonstrator for ICI. It is shown that whilst they are generally able to reproduce the observed cloud signals, for a given ice water path (IWP) there is considerable sensitivity to the cloud microphysics, including the distribution of ice mass within the cloud and the ice particle habit. Accurate retrievals from ICI will therefore require realistic representations of cloud microphysical properties.
  •  
29.
  • Jarvis, Samuel P., et al. (författare)
  • Measuring the mechanical properties of molecular conformers
  • 2015
  • Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 6
  • Tidskriftsartikel (refereegranskat)abstract
    • Scanning probe-actuated single molecule manipulation has proven to be an exceptionally powerful tool for the systematic atomic-scale interrogation of molecular adsorbates. To date, however, the extent to which molecular conformation affects the force required to push or pull a single molecule has not been explored. Here we probe the mechanochemical response of two tetra(4-bromophenyl)porphyrin conformers using non-contact atomic force microscopy where we find a large difference between the lateral forces required for manipulation. Remarkably, despite sharing very similar adsorption characteristics, variations in the potential energy surface are capable of prohibiting probe-induced positioning of one conformer, while simultaneously permitting manipulation of the alternative conformational form. Our results are interpreted in the context of dispersion-corrected density functional theory calculations which reveal significant differences in the diffusion barriers for each conformer. These results demonstrate that conformational variation significantly modifies the mechanical response of even simple porpyhrins, potentially affecting many other flexible molecules
  •  
30.
  • Jarvis, Samuel P., et al. (författare)
  • Physisorption Controls the Conformation and Density of States of an Adsorbed Porphyrin
  • 2015
  • Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 119:50, s. 27982-27994
  • Tidskriftsartikel (refereegranskat)abstract
    • Conformational changes caused by adsorption can dramatically affect a molecule's properties. Despite extensive study, however, the exact mechanisms underpinning conformational switching are often unclear. Here we show that the conformation of a prototypical flexible molecule, the free-base tetra(4-bromophenyl) porphyrin, adsorbed on Cu(111), depends critically on its precise adsorption site and that, remarkably, large conformational changes are dominated by van der Waals interactions between the molecule and the substrate surface. A combination of scanning probe microscopy, single-molecule manipulation, DFT with dispersion density functional theory, and molecular dynamics simulations show that van der Waals forces drive significant distortions of the molecular architecture so that the porphyrin can adopt one of two low-energy conformations. We find that adsorption driven by van der Waals forces alone is capable of causing large shifts in the molecular density of states, despite the apparent absence of chemical interactions. These findings highlight the essential role that van der Waals forces play in determining key molecular properties.
  •  
31.
  •  
32.
  •  
33.
  • Kersell, Heath, et al. (författare)
  • Some Future Perspectives in Ambient Pressure X-ray Spectroscopies : Atmospheric Pressure, Spatially Resolved and Multi-modal Experiments
  • 2021
  • Ingår i: Ambient Pressure Spectroscopy in Complex Chemical Environments. - Washington, DC : American Chemical Society. - 0097-6156 .- 1947-5918. - 9780841298125 - 9780841298118 ; 1396, s. 333-358
  • Bokkapitel (refereegranskat)abstract
    • This chapter introduces a selection of novel and emerging concepts in ambient pressure X-ray spectroscopies. Technical considerations and first photoemission experiments performed in and above 1 bar pressure are described. Then, X-ray spectroscopy experiments that provide high lateral (microscopy) and depth (X-ray standing-waves) resolution in ambient environments are discussed. The final part of the chapter introduces recent developments in multimodal instrumentation, such as the combination of ambient pressure X-ray Photoelectron Spectroscopy with Infrared spectroscopy and X-ray scattering.
  •  
34.
  •  
35.
  •  
36.
  • Pierre, M., et al. (författare)
  • The XXL Survey I. Scientific motivations - XMM-Newton observing plan - Follow-up observations and simulation programme
  • 2016
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 592
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. The quest for the cosmological parameters that describe our universe continues to motivate the scientific community to undertake very large survey initiatives across the electromagnetic spectrum. Over the past two decades, the Chandra and XMM-Newton observatories have supported numerous studies of X-ray-selected clusters of galaxies, active galactic nuclei (AGNs), and the X-ray background. The present paper is the first in a series reporting results of the XXL-XMM survey; it comes at a time when the Planck mission results are being finalised. Aims. We present the XXL Survey, the largest XMM programme totaling some 6.9 Ms to date and involving an international consortium of roughly 100 members. The XXL Survey covers two extragalactic areas of 25 deg(2) each at a point-source sensitivity of similar to 5 x 10(-15) erg s(-1) cm(-2) in the [0.5-2] keV band (completeness limit). The survey's main goals are to provide constraints on the dark energy equation of state from the space-time distribution of clusters of galaxies and to serve as a pathfinder for future, wide-area X-ray missions. We review science objectives, including cluster studies, AGN evolution, and large-scale structure, that are being conducted with the support of approximately 30 follow-up programmes. Methods. We describe the 542 XMM observations along with the associated multi-lambda and numerical simulation programmes. We give a detailed account of the X-ray processing steps and describe innovative tools being developed for the cosmological analysis. Results. The paper provides a thorough evaluation of the X-ray data, including quality controls, photon statistics, exposure and background maps, and sky coverage. Source catalogue construction and multi-lambda associations are briefly described. This material will be the basis for the calculation of the cluster and AGN selection functions, critical elements of the cosmological and science analyses. Conclusions. The XXL multi-lambda data set will have a unique lasting legacy value for cosmological and extragalactic studies and will serve as a calibration resource for future dark energy studies with clusters and other X-ray selected sources. With the present article, we release the XMM XXL photon and smoothed images along with the corresponding exposure maps.
  •  
37.
  • Pirkis, Jane, et al. (författare)
  • Suicide numbers during the first 9-15 months of the COVID-19 pandemic compared with pre-existing trends : An interrupted time series analysis in 33 countries
  • 2022
  • Ingår i: eClinicalMedicine. - : Elsevier. - 2589-5370. ; 51
  • Tidskriftsartikel (refereegranskat)abstract
    • Background Predicted increases in suicide were not generally observed in the early months of the COVID-19 pandemic. However, the picture may be changing and patterns might vary across demographic groups. We aimed to provide a timely, granular picture of the pandemic's impact on suicides globally. Methods We identified suicide data from official public-sector sources for countries/areas-within-countries, searching websites and academic literature and contacting data custodians and authors as necessary. We sent our first data request on 22nd June 2021 and stopped collecting data on 31st October 2021. We used interrupted time series (ITS) analyses to model the association between the pandemic's emergence and total suicides and suicides by sex-, age-and sex-by-age in each country/area-within-country. We compared the observed and expected numbers of suicides in the pandemic's first nine and first 10-15 months and used meta-regression to explore sources of variation. Findings We sourced data from 33 countries (24 high-income, six upper-middle-income, three lower-middle-income; 25 with whole-country data, 12 with data for area(s)-within-the-country, four with both). There was no evidence of greater-than-expected numbers of suicides in the majority of countries/areas-within-countries in any analysis; more commonly, there was evidence of lower-than-expected numbers. Certain sex, age and sex-by-age groups stood out as potentially concerning, but these were not consistent across countries/areas-within-countries. In the meta-regression, different patterns were not explained by countries' COVID-19 mortality rate, stringency of public health response, economic support level, or presence of a national suicide prevention strategy. Nor were they explained by countries' income level, although the meta-regression only included data from high-income and upper-middle-income countries, and there were suggestions from the ITS analyses that lower-middle-income countries fared less well. Interpretation Although there are some countries/areas-within-countries where overall suicide numbers and numbers for certain sex- and age-based groups are greater-than-expected, these countries/areas-within-countries are in the minority. Any upward movement in suicide numbers in any place or group is concerning, and we need to remain alert to and respond to changes as the pandemic and its mental health and economic consequences continue. Copyright (C) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
  •  
38.
  • Shavorskiy, Andrey, et al. (författare)
  • Time Resolved Ambient Pressure X-ray Photoelectron Spectroscopy
  • 2021
  • Ingår i: Ambient Pressure Spectroscopy in Complex Chemical Environments. - Washington, DC : American Chemical Society. - 0097-6156 .- 1947-5918. ; 1396, s. 219-248
  • Bokkapitel (refereegranskat)abstract
    • This chapter describes basic principles and recent advances in time-resolved X-ray Photoelectron Spectroscopy with particular emphasis on studies conducted in complex reaction environments. Specifically, it discusses different ways for obtaining time information and achieving different time resolutions in tr-(AP)XPS experiment, covering timescales from fs to s. This includes experimental setups at the free-electron lasers as well as electron storage rings and high-harmonic generation light sources. A variety of perturbations such as optical, mechanical, gas composition, temperature, and pressure is discussed. A number of examples are described that demonstrate the power of tr-APXPS in studies combining various timescales and perturbation methods.
  •  
39.
  •  
40.
  • Xiang, Jinbao, et al. (författare)
  • Hindered dialkyl ether synthesis with electrogenerated carbocations
  • 2019
  • Ingår i: Nature. - : NATURE PUBLISHING GROUP. - 0028-0836 .- 1476-4687. ; 573:7774, s. 398-
  • Tidskriftsartikel (refereegranskat)abstract
    • Hindered ethers are of high value for various applications; however, they remain an underexplored area of chemical space because they are difficult to synthesize via conventional reactions(1,2). Such motifs are highly coveted in medicinal chemistry, because extensive substitution about the ether bond prevents unwanted metabolic processes that can lead to rapid degradation in vivo. Here we report a simple route towards the synthesis of hindered ethers, in which electrochemical oxidation is used to liberate high-energy carbocations from simple carboxylic acids. These reactive carbocation intermediates, which are generated with low electrochemical potentials, capture an alcohol donor under non-acidic conditions; this enables the formation of a range of ethers (more than 80 have been prepared here) that would otherwise be difficult to access. The carbocations can also be intercepted by simple nucleophiles, leading to the formation of hindered alcohols and even alkyl fluorides. This method was evaluated for its ability to circumvent the synthetic bottlenecks encountered in the preparation of 12 chemical scaffolds, leading to higher yields of the required products, in addition to substantial reductions in the number of steps and the amount of labour required to prepare them. The use of molecular probes and the results of kinetic studies support the proposed mechanism and the role of additives under the conditions examined. The reaction manifold that we report here demonstrates the power of electrochemistry to access highly reactive intermediates under mild conditions and, in turn, the substantial improvements in efficiency that can be achieved with these otherwise-inaccessible intermediates.
  •  
41.
  •  
42.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-42 av 42

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy