| 1. |
- Reva, Viktor A., et al.
(författare)
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Extracorporeal Cardio-Pulmonary Resuscitation (E-CPR) in Traumatic Cardiac Arrests Caused by Penetrating Thoracic Injuries : A Series of Two Cases
- 2020
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Ingår i: Journal of endovascular resuscitation and trauma management. - Örebro : Örebro University Hospital. - 2002-7567. ; 4:1, s. 63-68
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Tidskriftsartikel (refereegranskat)abstract
- Background: We present two cases of thoracic penetrating injuries that necessitated extracorporeal cardiopulmonary resuscitation (E-CPR).Methods: Two male patients were admitted to hospital within 20-25 min: one with a chest stab wound and the other with a gunshot injury. Upon ongoing CPR, patient #1 underwent resuscitative sternotomy. Bleeding from a right ventricle injury was controlled, but cardiac arrest (CA) re-occurred. Patient #2 underwent immediate surgery due to multiple rib fractures and massive hemopneumothorax, and experienced multiple CAs. Due to refractory asystole with ongoing CPR, extracorporeal membrane oxygenation (ECMO) was initiated after 100 and 135 min, respectively. Primary lactate levels in cases #1 and #2 were 8 and 20 mmol/L, respectively.Results: In both cases, the femoral artery (17-19 Fr) and vein (25-27 Fr) were cannulated and connected to the Maquet ECMO circuit with a flow rate of 4-5 L/min. Return of spontaneous circulation was achieved within 20 min after ECMO initiation with relative stabilization. In patient #1, postoperative bleeding necessitated re-thoracotomy and hemorrhage control. In patient #2, left pulmonectomy and ligation of intercostal arteries was performed. 12/30 units of red blood cells, 16/45 units of fresh frozen plasma, and 2/8 units of platelets were given in cases #1/2, respectively. Lactate level increased to 25 mmol/L and decreased to 8 mmol/L in 5 hours, respectively. Both patients died in the ICU within 9 and 13 hours after admission due to bleeding.Conclusions: E-CPR allows vital function protection even in traumatic CA but necessitates appropriate resuscitation. If no bleeding control is achieved, then E-CPR is futile.
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| 2. |
- Sørensen, Lasse K., et al.
(författare)
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Thermal degradation of optical resonances in plasmonic nanoparticles
- 2022
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 14:2, s. 433-447
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Tidskriftsartikel (refereegranskat)abstract
- The dependence of plasmon resonance excitations in ultrafine (3-7 nm) gold nanoparticles on heating and melting is investigated. An integrated approach is adopted, where molecular dynamics simulations of the spatial and temporal development of the atoms constituting the nanoparticles generate trajectories out of which system conformations are sampled and extracted for calculations of plasmonic excitation cross sections which then are averaged over the sample configurations for the final result. The calculations of the plasmonic excitations, which take into account the temperature- and size-dependent relaxation of the plasmons, are carried out with a newly developed Extended Discrete Interaction Model (Ex-DIM) and complemented by multilayered Mie theory. The integrated approach clearly demonstrates the conditions for suppression of the plasmons starting at temperatures well below the melting point. We have found a strong inhomogeneous dependence of the atom mobility in the particle crystal lattice increasing from the center to its surface upon the temperature growth. The plasmon resonance suppression is associated with an increase of the mobility and in the amplitude of phonon vibrations of the lattice atoms accompanied by electron-phonon scattering. This leads to an increase in the relaxation constant impeding the plasmon excitation as the major source of the suppression, while the direct contribution from the increase in the lattice constant and its chaotization at melting is found to be minor. Experimental verification of the suppression of surface plasmon resonance is demonstrated for gold nanoparticles on a quartz substrate heated up to the melting temperature and above.
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| 3. |
- Utyushev, A. D., et al.
(författare)
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Engineering novel tunable optical high-Q nanoparticle array filters for a wide range of wavelengths
- 2020
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Ingår i: Optics Express. - : Optical Society of America. - 1094-4087. ; 28:2, s. 1426-1438
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Tidskriftsartikel (refereegranskat)abstract
- The interaction of non-monochromatic radiation with arrays comprising plasmonic and dielectric nanoparticles has been studied using the finite-difference time-domain electrodynamics method. It is shown that LiNbO3, TiO2, GaAs, Si, and Ge all-dielectric nanoparticle arrays can provide a complete selective reflection of an incident plane wave within a narrow spectral line of collective lattice resonance with a Q-factor of 103 or larger at various spectral ranges, while plasmonic refractory TiN and chemically stable Au nanoparticle arrays provide high-Q resonances with moderate reflectivity. Arrays with fixed dimensional parameters make it possible to fine-tune the position of a selected resonant spectral line by tilting the array relative to the direction of the incident radiation. These effects provide grounds for engineering novel selective tunable optical high-Q filters in a wide range of wavelengths, from visible to middle-IR.
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| 4. |
- Sørensen, Lasse K., et al.
(författare)
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Medium dependent optical response in ultra-fine plasmonic nanoparticles
- 2022
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 24:39, s. 24062-24075
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Tidskriftsartikel (refereegranskat)abstract
- We study the influence of media on the interaction of ultra-fine plasmonic nanoparticles (≤ 8 nm) with radiation. The important role of the surface layer of the nanoparticles, with properties that differ from the ones in the inner part, is established. Using an atomistic representation of the nanoparticle material and its interaction with light, we find a highly inhomogeneous distribution of the electric field inside and around the particles. It is predicted that with an increase in the refractive index of the ambient medium, the extension of the surface layer of atoms increases, something that also is accompanied by an enhanced red shift of the plasmon resonance band compared to large particles in which the influence of this layer and its relative volume is reduced. It is shown that the physical origin for the formation of a surface layer of atoms near the nanoparticle boundary is related to the anisotropy of the local environment of atoms in this layer which changes the conditions for the interaction of neighboring atoms with each other and with the incident radiation. It is shown that a growth of the refractive index of the ambient medium results in an increase in the local field in the dielectric cavity in which a plasmonic nanoparticle is embedded and which is accompanied by a growth of the amplitude of the plasmon resonance. We predict that in the ultra-fine regime the refractive index sensitivity shows a decreasing trend with respect to size which is opposite to that for larger particles. With the applied atomistic model this work demonstrates close relations between field distributions and properties of ultra-fine nanoparticles.
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