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| 2. |
- Nogly, P., et al.
(författare)
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Lipidic cubic phase injector is a viable crystal delivery system for time-resolved serial crystallography
- 2016
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Serial femtosecond crystallography (SFX) using X-ray free-electron laser sources is an emerging method with considerable potential for time-resolved pump-probe experiments. Here we present a lipidic cubic phase SFX structure of the light-driven proton pump bacteriorhodopsin (bR) to 2.3 angstrom resolution and a method to investigate protein dynamics with modest sample requirement. Time-resolved SFX (TR-SFX) with a pump-probe delay of 1ms yields difference Fourier maps compatible with the dark to M state transition of bR. Importantly, the method is very sample efficient and reduces sample consumption to about 1mg per collected time point. Accumulation of M intermediate within the crystal lattice is confirmed by time-resolved visible absorption spectroscopy. This study provides an important step towards characterizing the complete photocycle dynamics of retinal proteins and demonstrates the feasibility of a sample efficient viscous medium jet for TR-SFX.
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| 3. |
- Galli, L., et al.
(författare)
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Electronic damage in S atoms in a native protein crystal induced by an intense X-ray free-electron laser pulse
- 2015
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Ingår i: Structural Dynamics. - : AIP Publishing. - 2329-7778. ; 2:4
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Tidskriftsartikel (refereegranskat)abstract
- Current hard X-ray free-electron laser (XFEL) sources can deliver doses to biological macromolecules well exceeding 1 GGy, in timescales of a few tens of femtoseconds. During the pulse, photoionization can reach the point of saturation in which certain atomic species in the sample lose most of their electrons. This electronic radiation damage causes the atomic scattering factors to change, affecting, in particular, the heavy atoms, due to their higher photoabsorption cross sections. Here, it is shown that experimental serial femtosecond crystallography data collected with an extremely bright XFEL source exhibit a reduction of the effective scattering power of the sulfur atoms in a native protein. Quantitative methods are developed to retrieve information on the effective ionization of the damaged atomic species from experimental data, and the implications of utilizing new phasing methods which can take advantage of this localized radiation damage are discussed.
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| 4. |
- Gati, Istvan, et al.
(författare)
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Culturing of diagnostic muscle biopsies as spheroid-like structures: a pilot study of morphology and viability
- 2010
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Ingår i: Neurological Research. - : Forefront Publishing Group. - 0161-6412 .- 1743-1328. ; 32:6, s. 650-655
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of this study was to establish three-dimensional cultures originating from muscle biopsies and evaluate the viability and morphology. Method: Muscle biopsies from patients with suspected neuromuscular disorders were obtained and established as primary muscle tissue cultures. Tissue pieces, 1-2 mm of diameters, were placed in culture medium and subjected to sporadic stirring to prevent attachment and outgrowth as monolayer cells. Morphology and ability to attach to the surface were investigated by light microscopy. Viability was evaluated by Tc-99m-tetrofosmin uptake. After 1 month, histology was evaluated by light microscopy and immunocytochemistry. The findings of a healthy muscle and a dystrophic muscle were compared. Results: Initially, the tissue pieces were unshaped but formed spheroid-like structures during the culture period. For dystrophic muscle, attachment capacity to the surface was initially potent and decreased during the culture period, whereas control muscle showed weak attachment from the start that increased during the culture period. The uptake of Tc-99m-tetrofosmin increased in control muscle, while it decreased in dystrophic muscle, during the culture period. The histological investigation demonstrated larger destruction of myofiber, weaker satellite cell activation and reduced myofiber regeneration in the dystrophic muscle as compared to the control muscle. Conclusion: The cellular components of the muscle tissue can survive and proliferate as spheroid-like primary cultures. The cellular composition resembles the in vivo condition, which allows studies of degeneration of the original fibers, and activation and proliferation of the satellite cells. The culture system may provide better understanding of the degeneration and regeneration processes in different muscle disorders and allow investigations of pharmacological interventions.
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| 5. |
- Gati, Istvan, 1954-, et al.
(författare)
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Effects of inhibitors of the arachidonic acid cascade on primary muscle culture from a Duchenne muscular dystrophy patient
- 2007
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Ingår i: Prostaglandins, Leukotrienes and Essential Fatty Acids. - : Elsevier BV. - 0952-3278 .- 1532-2823. ; 77:3-4, s. 217-223
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to elucidate the mechanisms of action for potential targets of therapeutic intervention related to the arachidonic acid cascade in muscular dystrophy. Primary cultures from a Duchenne patient were used to study the expression of dystrophin-1, utrophin, desmin, neonatal myosin heavy chain (MHCn) and Bcl-2 during inhibition of phospholipase A2 (PLA2), cyclooxygenase (COX) and lipoxygenase (LOX). Hypo-osmotic treatment was applied in order to trigger Ca2+ influx and PLA2 activity. Inhibition of PLA2 and LOX with prednisolone and nordihydroguaiaretic acid (NDGA) caused a semi-quantitative increase of utrophin and Bcl-2-, and a dose-dependent, quantitative increase of desmin expression, an effect that was augmented by hypo-osmotic treatment. Our results indicate that LOX inhibitors, similarly to corticosteroids, can be beneficial in the treatment of muscular dystrophies. © 2007 Elsevier Ltd. All rights reserved.
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| 6. |
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| 7. |
- Liu, Wei, et al.
(författare)
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Serial Femtosecond Crystallography of G Protein-Coupled Receptors
- 2013
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 342:6165, s. 1521-1524
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Tidskriftsartikel (refereegranskat)abstract
- X-ray crystallography of G protein-coupled receptors and other membrane proteins is hampered by difficulties associated with growing sufficiently large crystals that withstand radiation damage and yield high-resolution data at synchrotron sources. We used an x-ray free-electron laser (XFEL) with individual 50-femtosecond-duration x-ray pulses to minimize radiation damage and obtained a high-resolution room-temperature structure of a human serotonin receptor using sub-10-micrometer microcrystals grown in a membrane mimetic matrix known as lipidic cubic phase. Compared with the structure solved by using traditional microcrystallography from cryo-cooled crystals of about two orders of magnitude larger volume, the room-temperature XFEL structure displays a distinct distribution of thermal motions and conformations of residues that likely more accurately represent the receptor structure and dynamics in a cellular environment.
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| 8. |
- Masoudi, Meysam, et al.
(författare)
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Green Mobile Networks for 5G and Beyond
- 2019
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Ingår i: IEEE Access. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2169-3536. ; 7, s. 107270-107299
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Tidskriftsartikel (refereegranskat)abstract
- The heated 5G network deployment race has already begun with the rapid progress in standardization efforts, backed by the current market availability of 5G-enabled network equipment, ongoing 5G spectrum auctions, early launching of non-standalone 5G network services in a few countries, among others. In this paper, we study current and future wireless networks from the viewpoint of energy efficiency (EE) and sustainability to meet the planned network and service evolution toward, along, and beyond 5G, as also inspired by the findings of the EU Celtic-Plus SooGREEN Project. We highlight the opportunities seized by the project efforts to enable and enrich this green nature of the network as compared to existing technologies. In specific, we present innovative means proposed in SooGREEN to monitor and evaluate EE in 5G networks and beyond. Further solutions are presented to reduce energy consumption and carbon footprint in the different network segments. The latter spans proposed virtualized/cloud architectures, efficient polar coding for fronthauling, mobile network powering via renewable energy and smart grid integration, passive cooling, smart sleeping modes in indoor systems, among others. Finally, we shed light on the open opportunities yet to be investigated and leveraged in future developments.
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| 9. |
- Rocha, H., et al.
(författare)
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SooGREEN : Service-oriented optimization of green mobile networks
- 2017
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Ingår i: 2017 15th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks, WiOpt 2017. - : Institute of Electrical and Electronics Engineers (IEEE). - 9783901882906
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Konferensbidrag (refereegranskat)abstract
- Today, mobile networks are witnessing an exponential growth of traffic volumes, linked to new services, especially for smart cities and smart-grid. The European Celtic-Plus SooGREEN project, started mid 2015, is targeting to reduce the energy consumption of the services in different mobile architectures in interaction with smart-grid. So GREEN is focused on the services energy consumption modelling and measurement, the dynamic optimization of the mobile access network and of the content delivery, the design of an Energy Efficient Virtualized and Centralized Radio Access Network (RAN), and the bi-directional interaction of the mobile network with the smart-grid. This paper presents insight into the project after its first year, and discusses research trends in green communication networks for the future.
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| 10. |
- Weierstall, Uwe, et al.
(författare)
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Lipidic cubic phase injector facilitates membrane protein serial femtosecond crystallography
- 2014
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 5, s. 3309-
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Tidskriftsartikel (refereegranskat)abstract
- Lipidic cubic phase (LCP) crystallization has proven successful for high-resolution structure determination of challenging membrane proteins. Here we present a technique for extruding gel-like LCP with embedded membrane protein microcrystals, providing a continuously renewed source of material for serial femtosecond crystallography. Data collected from sub-10-mu m-sized crystals produced with less than 0.5 mg of purified protein yield structural insights regarding cyclopamine binding to the Smoothened receptor.
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