| 1. |
- Staude, I. R., et al.
(författare)
-
Directional turnover towards larger-ranged plants over time and across habitats
- 2022
-
Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 25:2, s. 466-82
-
Tidskriftsartikel (refereegranskat)abstract
- Species turnover is ubiquitous. However, it remains unknown whether certain types of species are consistently gained or lost across different habitats. Here, we analysed the trajectories of 1827 plant species over time intervals of up to 78 years at 141 sites across mountain summits, forests, and lowland grasslands in Europe. We found, albeit with relatively small effect sizes, displacements of smaller- by larger-ranged species across habitats. Communities shifted in parallel towards more nutrient-demanding species, with species from nutrient-rich habitats having larger ranges. Because these species are typically strong competitors, declines of smaller-ranged species could reflect not only abiotic drivers of global change, but also biotic pressure from increased competition. The ubiquitous component of turnover based on species range size we found here may partially reconcile findings of no net loss in local diversity with global species loss, and link community-scale turnover to macroecological processes such as biotic homogenisation.
|
|
| 2. |
- Porro, M., et al.
(författare)
-
The MiniSDD-Based 1-Mpixel Camera of the DSSC Project for the European XFEL
- 2021
-
Ingår i: IEEE Transactions on Nuclear Science. - : Institute of Electrical and Electronics Engineers Inc.. - 0018-9499 .- 1558-1578. ; 68:6, s. 1334-1350
-
Tidskriftsartikel (refereegranskat)abstract
- The first DSSC 1-Mpixel camera became available at the European XFEL (EuXFEL) in the Hamburg area in February 2019. It was successfully tested, installed, and commissioned at the Spectroscopy and Coherent Scattering Instrument. DSSC is a high-speed, large-area, 2-D imaging detector system optimized for photon science applications in the energy range between 0.25 and 6 keV. The camera is based on direct conversion Si sensors and is composed of 1024 × 1024 pixels of hexagonal shape with a side length of 136∼μm. The 256 application-specific integrated circuits (ASICs) provide full parallel readout, comprising analog filtering, digitization, and in-pixel data storage. In order to cope with the demanding X-ray pulse time structure of the EuXFEL, the DSSC provides a peak frame rate of 4.5 MHz. The first Mpixel camera is equipped with miniaturized silicon drift detector (MiniSDD) pixel arrays. The intrinsic response of the pixels and the linear readout limit the dynamic range but allow one to achieve noise values of about 60 electrons r.m.s. at the highest frame rate. The challenge of providing high-dynamic range (104 photons/pixel/pulse) and single-photon detection simultaneously requires a nonlinear system front end, which will be obtained with the DEPFET active pixel technology foreseen for the advanced version of the camera. This technology will provide lower noise and a nonlinear response at the sensor level. This article describes the architecture of the whole detector system together with the main experimental results achieved up to now. © 1963-2012 IEEE.
|
|
| 3. |
- Hansen, K., et al.
(författare)
-
Qualification and Integration Aspects of the DSSC Mega-Pixel X-Ray Imager
- 2019
-
Ingår i: IEEE Transactions on Nuclear Science. - : Institute of Electrical and Electronics Engineers Inc.. - 0018-9499 .- 1558-1578. ; 66:8, s. 1966-1975
-
Tidskriftsartikel (refereegranskat)abstract
- The focal-plane module is the key component of the DEPFET sensor with signal compression (DSSC) mega-pixel X-ray imager and handles the data of 128 ×512 pixels. We report on assembly-related aspects, discuss the experimental investigation of bonding behavior of different adhesives, and present the metrology and electrical test results of the production. The module consists of two silicon (Si) sensors with flip-chip connected CMOS integrated circuits, a Si-heat spreader, a low-temperature co-fired ceramics circuit board, and a molybdenum frame. A low-modulus urethane-film adhesive fills the gaps between on-board components and frame. It is also used between board and heat spreader, reduces the misfit strain, and minimizes the module warpage very efficiently. The heat spreader reduces the on-board temperature gradient by about one order of magnitude. The placement precision of the bare modules to each other and the frame is characterized by a standard deviation below 10 and 65 μ m, respectively. The displacement due to the in-plane rotation and vertical tilting errors remains below 80 and 50 μm, respectively. The deflection of the sensor plane shows a mean value below 30 μm with a standard deviation below 15 μm. Less than 4% of the application-specified integrated circuits (ASICs) exhibit a malfunction. More than two-thirds of the sensors have a maximum leakage current below 1 μA. © 1963-2012 IEEE.
|
|
| 4. |
- Sarapa, N., et al.
(författare)
-
Assessment of normal and tumor tissue uptake of MAG-CPT, a polymer-bound prodrug of camptothecin, in patients undergoing elective surgery for colorectal carcinoma
- 2003
-
Ingår i: Cancer Chemother Pharmacol. ; 52:5, s. 424-30
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: MAG-camptothecin (MAG-CPT) is the lead compound of a novel drug delivery system in which an active cytotoxic moiety, camptothecin (CPT), is covalently linked to a soluble polymeric carrier (MAG) to form an inactive prodrug. The mechanism of action of CPT remains unaltered, but the delivery system is thought to allow the carrier-bound drug to accumulate in tumor tissues and release the active CPT locally. This proof-of-concept clinical study was designed to determine whether MAG-CPT was preferentially delivered to or retained in tumor tissue compared to adjacent normal tissue or plasma, and to estimate the degree of intratissue release of CPT. METHODS: This was an open, non-randomized study in ten adult patients scheduled for elective surgery for colorectal cancer. Patients received a single dose of 60 mg/m2 (CPT equivalent) of MAG-CPT 24 h, 3 days or 7 days prior to surgery. Plasma, tumor, and adjacent normal tissue samples were collected simultaneously at the time of surgery and analyzed for MAG-bound and released CPT concentrations. RESULTS: MAG-bound and free CPT concentrations in plasma, tumor, and normal tissue achieved equilibrium by 24 h after dosing, declining in parallel up to 7 days after dosing. MAG-bound CPT was delivered to similar levels to tumor and normal tissue. At 24 h after dosing, the mean+/-SD MAG-bound CPT concentrations were 861+/-216 ng/g in tumor and 751+/-215 ng/g in adjacent normal tissue, and free CPT concentrations were lower in tumor than in normal tissue (12.2+/-4.7 ng/g and 21.9+/-6.7 ng/g, respectively). At 24 h after dosing, mean+/-SD ratios of MAG-bound and free CPT in tumor and plasma were 0.13+/-0.03 and 0.22+/-0.09, respectively, and the ratios did not change for up to 7 days after dosing, indicating a lack of preferential retention of MAG-bound CPT or release of free CPT in tumor. These results are in marked contrast to previous data from animal tumor xenograft studies, where MAG-CPT levels were higher in tissue than in plasma at 3 and 7 days after a single i.v. dose. CONCLUSIONS: Delivery of CPT to the target tumor tissue is achievable by means of the MAG-CPT polymer-bound delivery system, with the equilibrium between plasma and tumor tissue concentrations of released CPT being established within 24 h after dosing. However, preferential retention of MAG-bound or released CPT in the tumor relative to normal tissue or plasma was not detected during the 7 days after dosing. The methods employed in our study could be of use in making "go/no-go" decisions on further development of anticancer drugs.
|
|
| 5. |
- Manzanillas, L., et al.
(författare)
-
Development of multi-element monolithic germanium detectors for X-ray detection at synchrotron facilities
- 2023
-
Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 1047
-
Tidskriftsartikel (refereegranskat)abstract
- In past years efforts have concentrated on the development of arrays of Silicon Drift Detectors for X-ray spectroscopy. This is in stark contrast to the little effort that has been devoted to the improvement of germanium detectors, in particular for synchrotron applications. Germanium detectors have better energy resolution and are more efficient in detecting high energy photons than silicon detectors. In this context, the detector consortium of the European project LEAPS-INNOV has set an ambitious R&D program devoted to the development of a new generation of multi-element monolithic germanium detectors for X-ray detection. In order to improve the performance of the detector under development, simulations of the different detector design options have been performed. In this contribution, the efforts in terms of R&D are outlined with a focus on the modelization of the detector geometry and first performance results. These performance results show that a signal-to-background ratio larger than 1000 can be achieved in the energy range of interest from 5 keV to 100 keV.
|
|
| 6. |
- Orsini, F., et al.
(författare)
-
XAFS-DET : A new high throughout X-ray spectroscopy detector system developed for synchrotron applications
- 2023
-
Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 1045
-
Tidskriftsartikel (refereegranskat)abstract
- The high brilliance and coherent beams resulting from recent upgraded synchrotron radiation facilities open the way for a large range of experiments, where detectors play a key role in the techniques and methods developed to fully exploit the upgraded synchrotron. For instance, one of the major limitations of XAFS experiment is the performance of the detectors. In order to be able to measure more challenging samples and to cope with the very high photon flux of the current and future (diffraction limited) sources, technological developments of detectors are necessary. In this framework, the germanium detector developed in the European project LEAPS-INNOV aims at improving several technological aspects. This type of detector represents a very important class of instruments for X-ray spectroscopy due to the fact that they enable to detect efficiently photons of considerable higher energy with respect to silicon detectors. The objective of this project consists in pushing the detector performance beyond the state-of-the-art. Preliminary layout and main choices for the design studies of this new detector are presented in this paper.
|
|
| 7. |
|
|
| 8. |
- Zhou Hagström, Nanna, 1993-, et al.
(författare)
-
Megahertz-rate Ultrafast X-ray Scattering and Holographic Imaging at the European XFEL
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The advent of X-ray free-electron lasers (XFELs) has revolutionized fundamental science, from atomic to condensed matter physics, from chemistry to biology, giving researchers access to X-rays with unprecedented brightness, coherence, and pulse duration. All XFEL facilities built until recently provided X-ray pulses at a relatively low repetition rate, with limited data statistics. Here, we present the results from the first megahertz repetition rate X-ray scattering experiments at the Spectroscopy and Coherent Scattering (SCS) instrument of the European XFEL. We illustrate the experimental capabilities that the SCS instrument offers, resulting from the operation at MHz repetition rates and the availability of the novel DSSC 2D imaging detector. Time-resolved magnetic X-ray scattering and holographic imaging experiments in solid state samples were chosen as representative examples, providing an ideal test-bed for operation at megahertz rates. Nevertheless, our results are relevant and applicable to any other non-destructive XFEL experiments in the soft X-ray range.
|
|
| 9. |
- Zhou Hagström, Nanna, 1993-, et al.
(författare)
-
Megahertz-rate ultrafast X-ray scattering and holographic imaging at the European XFEL
- 2022
-
Ingår i: Journal of Synchrotron Radiation. - : International Union of Crystallography (IUCr). - 0909-0495 .- 1600-5775. ; 29, s. 1454-1464
-
Tidskriftsartikel (refereegranskat)abstract
- The advent of X-ray free-electron lasers (XFELs) has revolutionized fundamental science, from atomic to condensed matter physics, from chemistry to biology, giving researchers access to X-rays with unprecedented brightness, coherence and pulse duration. All XFEL facilities built until recently provided X-ray pulses at a relatively low repetition rate, with limited data statistics. Here, results from the first megahertz-repetition-rate X-ray scattering experiments at the Spectroscopy and Coherent Scattering (SCS) instrument of the European XFEL are presented. The experimental capabilities that the SCS instrument offers, resulting from the operation at megahertz repetition rates and the availability of the novel DSSC 2D imaging detector, are illustrated. Time-resolved magnetic X-ray scattering and holographic imaging experiments in solid state samples were chosen as representative, providing an ideal test-bed for operation at megahertz rates. Our results are relevant and applicable to any other non-destructive XFEL experiments in the soft X-ray range.
|
|
| 10. |
- Lassalle, A., et al.
(författare)
-
Effect of visual stimuli of pain on empathy brain network in people with and without Autism Spectrum Disorder
- 2018
-
Ingår i: European Journal of Neuroscience. - : Wiley. - 0953-816X .- 1460-9568. ; 48:6, s. 2333-2342
-
Tidskriftsartikel (refereegranskat)abstract
- The extent to which affective empathy is impaired in Autism Spectrum Disorder (ASD) remains unclear, as some-but not all-previous neuroimaging studies investigating empathy for pain in ASD have shown similar activation levels to those of neurotypicals individuals. These inconsistent results could be due to the use of different empathy-eliciting stimuli. While some studies used pictures of faces exhibiting a painful expression, others used pictures of limbs in painful situations. In this study, we used fMRI to compare activation in areas associated with empathy processing (empathy network) for these two types of stimuli in 31 participants (16 with ASD, 15 controls). We found a group difference in the inferior frontal gyrus (IFG) and the thalamus when participants viewed stimuli of limbs in painful situations, but not when they viewed face stimuli with a painful expression. Both groups of participants activated their empathy network more when viewing pictures of limbs in painful situations than when viewing pictures of faces with a painful expression; this increased activation for limbs versus faces was significantly enhanced in controls relative to ASD participants, especially in the secondary somatosensory cortex (SII). Our findings suggest that empathy defect of people with ASD is contingent upon the type of stimuli used, and may be related to the level of Mirror Neuron System involvement, as brain regions showing group differences (IFG, SII) underlie embodiment. We discuss the potential clinical implications of our findings in terms of developing interventions boosting the empathetic abilities of people with ASD.
|
|
