| 1. |
- Allum, Felix, et al.
(författare)
-
Coulomb explosion imaging of CH3I and CH2CII photodissociation dynamics
- 2018
-
Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 149:20
-
Tidskriftsartikel (refereegranskat)abstract
- The photodissociation dynamics of CH3I and CH2CII at 272 nm were investigated by time-resolved Coulomb explosion imaging, with an intense non-resonant 815nmprobe pulse. Fragment ion momenta over a widem/z range were recorded simultaneously by coupling a velocity map imaging spectrometer with a pixel imaging mass spectrometry camera. For both molecules, delay-dependent pump-probe features were assigned to ultraviolet-induced carbon-iodine bond cleavage followed by Coulomb explosion. Multi-mass imaging also allowed the sequential cleavage of both carbon-halogen bonds in CH2ClI to be investigated. Furthermore, delay-dependent relative fragment momenta of a pair of ions were directly determined using recoil-frame covariance analysis. These results are complementary to conventional velocity map imaging experiments and demonstrate the application of time-resolved Coulomb explosion imaging to photoinduced real-time molecular motion.
|
|
| 2. |
- Amini, Kasra, et al.
(författare)
-
Alignment, orientation, and Coulomb explosion of difluoroiodobenzene studied with the pixel imaging mass spectrometry (PImMS) camera
- 2017
-
Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 147:1
-
Tidskriftsartikel (refereegranskat)abstract
- Laser-induced adiabatic alignment and mixed-field orientation of 2,6-difluoroiodobenzene (C6H3F2I) molecules are probed by Coulomb explosion imaging following either near-infrared strong-field ionization or extreme-ultraviolet multi-photon inner-shell ionization using free-electron laser pulses. The resulting photoelectrons and fragment ions are captured by a double-sided velocity map imaging spectrometer and projected onto two position-sensitive detectors. The ion side of the spectrometer is equipped with a pixel imaging mass spectrometry camera, a time-stamping pixelated detector that can record the hit positions and arrival times of up to four ions per pixel per acquisition cycle. Thus, the time-of-flight trace and ion momentum distributions for all fragments can be recorded simultaneously. We show that we can obtain a high degree of one-and three-dimensional alignment and mixed-field orientation and compare the Coulomb explosion process induced at both wavelengths.
|
|
| 3. |
- Amini, Kasra, et al.
(författare)
-
Photodissociation of aligned CH3I and C6H3F2I molecules probed with time-resolved Coulomb explosion imaging by site-selective extreme ultraviolet ionization
- 2018
-
Ingår i: Structural Dynamics. - : AIP Publishing. - 2329-7778. ; 5:1
-
Tidskriftsartikel (refereegranskat)abstract
- We explore time-resolved Coulomb explosion induced by intense, extreme ultraviolet (XUV) femtosecond pulses from a free-electron laser as a method to image photo-induced molecular dynamics in two molecules, iodomethane and 2,6-difluoroiodobenzene. At an excitation wavelength of 267 nm, the dominant reaction pathway in both molecules is neutral dissociation via cleavage of the carbon-iodine bond. This allows investigating the influence of the molecular environment on the absorption of an intense, femtosecond XUV pulse and the subsequent Coulomb explosion process. We find that the XUV probe pulse induces local inner-shell ionization of atomic iodine in dissociating iodomethane, in contrast to non-selective ionization of all photofragments in difluoroiodobenzene. The results reveal evidence of electron transfer from methyl and phenyl moieties to a multiply charged iodine ion. In addition, indications for ultrafast charge rearrangement on the phenyl radical are found, suggesting that time-resolved Coulomb explosion imaging is sensitive to the localization of charge in extended molecules.
|
|
| 4. |
- Brasse, Felix, et al.
(författare)
-
Time-resolved inner-shell photoelectron spectroscopy : From a bound molecule to an isolated atom
- 2018
-
Ingår i: Physical Review A: covering atomic, molecular, and optical physics and quantum information. - 2469-9926 .- 2469-9934. ; 97:4
-
Tidskriftsartikel (refereegranskat)abstract
- Due to its element and site specificity, inner-shell photoelectron spectroscopy is a widely used technique to probe the chemical structure of matter. Here, we show that time-resolved inner-shell photoelectron spectroscopy can be employed to observe ultrafast chemical reactions and the electronic response to the nuclear motion with high sensitivity. The ultraviolet dissociation of iodomethane (CH3I) is investigated by ionization above the iodine 4d edge, using time-resolved inner-shell photoelectron and photoion spectroscopy. The dynamics observed in the photoelectron spectra appear earlier and are faster than those seen in the iodine fragments. The experimental results are interpreted using crystal-field and spin-orbit configuration interaction calculations, and demonstrate that time-resolved inner-shell photoelectron spectroscopy is a powerful tool to directly track ultrafast structural and electronic transformations in gas-phase molecules.
|
|
| 5. |
- Burt, Michael, et al.
(författare)
-
Coulomb-explosion imaging of concurrent CH2BrI photodissociation dynamics
- 2017
-
Ingår i: Physical Review A: covering atomic, molecular, and optical physics and quantum information. - 2469-9926 .- 2469-9934. ; 96:4
-
Tidskriftsartikel (refereegranskat)abstract
- The dynamics following laser-induced molecular photodissociation of gas-phase CH2BrI at 271.6 nm were investigated by time-resolved Coulomb-explosion imaging using intense near-IR femtosecond laser pulses. The observed delay-dependent photofragment momenta reveal that CH2BrI undergoes C-I cleavage, depositing 65.6% of the available energy into internal product states, and that absorption of a second UV photon breaks the C-Br bond of C(H)2Br. Simulations confirm that this mechanism is consistent with previous data recorded at 248 nm, demonstrating the sensitivity of Coulomb-explosion imaging as a real-time probe of chemical dynamics.
|
|
| 6. |
- Engström, Gunnar, et al.
(författare)
-
The Swedish CArdioPulmonary BioImage Study : objectives and design
- 2015
-
Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 278:6, s. 645-659
-
Tidskriftsartikel (refereegranskat)abstract
- Cardiopulmonary diseases are major causes of death worldwide, but currently recommended strategies for diagnosis and prevention may be outdated because of recent changes in risk factor patterns. The Swedish CArdioPulmonarybioImage Study (SCAPIS) combines the use of new imaging technologies, advances in large-scale 'omics' and epidemiological analyses to extensively characterize a Swedish cohort of 30 000 men and women aged between 50 and 64 years. The information obtained will be used to improve risk prediction of cardiopulmonary diseases and optimize the ability to study disease mechanisms. A comprehensive pilot study in 1111 individuals, which was completed in 2012, demonstrated the feasibility and financial and ethical consequences of SCAPIS. Recruitment to the national, multicentre study has recently started.
|
|
| 7. |
- Fagerlönn, Johan, et al.
(författare)
-
Acoustic vehicle alerting systems : Will they affect the acceptance of electric vehicles?
- 2018
-
Ingår i: ACM International Conference Proceeding Series. - New York, NY, USA : ACM. - 9781450366090
-
Konferensbidrag (refereegranskat)abstract
- Vehicles powered by electric motors can be very quiet at low speeds, which can lead to new road safety issues. The European Parliament has decided that quiet vehicles should be equipped with an Acoustic Vehicle Alerting System (AVAS). The main purpose of the studies presented in this paper was to investigate whether future requirements could affect people's acceptance of electric vehicles (EVs). The strategy in the first study was to create an immersive, simulated auditory environment where people could experience the sounds of future traffic situations. The second study was conducted with a car on a test track. The results suggest that the requirements are not likely to have a major negative effect on people's experience of EVs or willingness to buy an EV. However, the sounds can have a certain negative effect on emotional response and acceptance, which should be considered by manufacturers. The results of the test track study indicate that unprotected road users may appreciate the function of an AVAS sound. The work did not reveal any large differences between AVAS sounds. But in the simulated environment, sounds designed to resemble an internal combustion engine tended to receive more positive scores. © 2018 Copyright is held by the owner/author(s).
|
|
| 8. |
- Johnsson, Linus, 1978-, et al.
(författare)
-
Autonomy is a Right, Not a Feat : How Theoretical Misconceptions have Muddled the Debate on Dynamic Consent to Biobank Research
- 2016
-
Ingår i: Bioethics. - : Wiley. - 0269-9702 .- 1467-8519. ; 30:7, s. 471-478
-
Tidskriftsartikel (refereegranskat)abstract
- Should people be involved as active participants in longitudinal medical research, as opposed to remaining passive providers of data and material? We argue in this article that misconceptions of 'autonomy' as a kind of feat rather than a right are to blame for much of the confusion surrounding the debate of dynamic versus broad consent. Keeping in mind two foundational facts of human life, freedom and dignity, we elaborate three moral principles - those of autonomy, integrity and authority - to better see what is at stake. Respect for autonomy is to recognize the other's right to decide in matters that are important to them. Respect for integrity is to meet, in one's relationship with the other, their need to navigate the intersection between private and social life. Respect for authority is to empower the other - to help them to cultivate their responsibility as citizens. On our account, to force information onto someone who does not want it is not to respect that person's autonomy, but to violate integrity in the name of empowerment. Empowerment, not respect for autonomy, is the aim that sets patient-centred initiatives employing a dynamic consent model apart from other consent models. Whether this is ultimately morally justified depends on whether empowerment ought to be a goal of medical research, which is questionable.
|
|
| 9. |
- Jonsson, Stefan, et al.
(författare)
-
Identification of sequence variants influencing immunoglobulin levels
- 2017
-
Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 49:8, s. 1182-1191
-
Tidskriftsartikel (refereegranskat)abstract
- Immunoglobulins are the effector molecules of the adaptive humoral immune system. In a genome-wide association study of 19,219 individuals, we found 38 new variants and replicated 5 known variants associating with IgA, IgG or IgM levels or with composite immunoglobulin traits, accounted for by 32 loci. Variants at these loci also affect the risk of autoimmune diseases and blood malignancies and influence blood cell development. Notable associations include a rare variant at RUNX3 decreasing IgA levels by shifting isoform proportions (rs188468174[C>T]: P = 8.3 × 10(-55), β = -0.90 s.d.), a rare in-frame deletion in FCGR2B abolishing IgG binding to the encoded receptor (p.Asn106del: P = 4.2 × 10(-8), β = 1.03 s.d.), four IGH locus variants influencing class switching, and ten new associations with the HLA region. Our results provide new insight into the regulation of humoral immunity.
|
|
| 10. |
- Kühn, Sergei, et al.
(författare)
-
The ELI-ALPS facility : The next generation of attosecond sources
- 2017
-
Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 50:13
-
Forskningsöversikt (refereegranskat)abstract
- This review presents the technological infrastructure that will be available at the Extreme Light Infrastructure Attosecond Light Pulse Source (ELI-ALPS) international facility. ELI-ALPS will offer to the international scientific community ultrashort pulses in the femtosecond and attosecond domain for time-resolved investigations with unprecedented levels of high quality characteristics. The laser sources and the attosecond beamlines available at the facility will make attosecond technology accessible for scientists lacking access to these novel tools. Time-resolved investigation of systems of increasing complexity is envisaged using the end stations that will be provided at the facility.
|
|
