Harte Röntgenstrahlung aus relativistschen Laserplasmen und laserinduzierte Kernreaktionen

Durch die Wechselwirkung hochintensiver Lichtpulse mit Materie wird energiereiche Röntgenlinien- und Bremsstrahlung erzeugt. Die Arbeit stellt Experimente und analytische Betrachtungen zur Erzeugung intensiver K-Schalen-Strahlung bei ultrahohen Intensitäten vor. Die Photonenenergien laserproduzierter Bremsstrahlung erreichen Werte im Bereich der Riesenresonanzen von Kernen. Es werden Experimente zu lasergetriebenen Kernreaktionen wie Photospaltung und photoinduzierter Neutronenemission präsentiert. Die Messung eines Kernreaktionsquerschnitts demonstriert die Einsatzmöglichkeit intensiver Laser für die Beantwortung kernphysikalischer Fragestellungen

Thermic sealing in femoral catheterization: First experience with the Secure Device

Background: Devices currently used to achieve hemostasis of the femoral artery following percutaneous cardiac catheterization are associated with vascular complications and remnants of artificial materials are retained at the puncture site. The Secure arterial closure Device induces hemostasis by utilizing thermal energy, which causes collagen shrinking and swelling. In comparison to established devices, it has the advantage of leaving no foreign material in the body following closing. This study was designed to evaluate the efficacy and safety of the Secure Device to close the puncture site following percutaneous cardiac catheterization. Methods: The Secure Device was evaluated in a prospective non-randomized single-center trial with patients undergoing 6 F invasive cardiac procedures. A total of 67 patients were enrolled and the device was utilized in 63 patients. Fifty diagnostic and 13 interventional cases were evaluated. Femoral artery puncture closure was performed immediately after completion of the procedure. Time to hemostasis (TTH), time to ambulation (TTA) and data regarding short-term and 30-day clinical follow-up were recorded. Results: Mean TTH was 4:30 ± 2:15 min in the overall observational group. A subpopulation of patients receiving anticoagulants had a TTH of 4:53 ± 1:43 min. There were two access site complications (hematoma > 5 cm). No major adverse events were identified during hospitalization or at the 30 day follow-up. Conclusions: The new Secure Device demonstrates that it is feasible in diagnostic and interventional cardiac catheterization. With respect to safety, the Secure Device was non-inferior to other closure devices as tested in the ISAR closure trial

X-Ray Absorber Design and Calculations for the EBS Storage Ring

International audienceThe Extremely Brilliant Source (EBS) of the ESRF will hold new type of X-Ray absorbers: a new material will be used (CuCr1Zr suggested by *) together with a novel design integrating: - CF flange are machined in the absorber body. No weld, no braze. - Optimized toothed surface profile, reducing the induced thermal stresses. - Compton and Rayleigh scattering integrated blocking shapes. - Concentric cooling channels. A brief overview of the new design and concepts will be given. The presentation will then focus on thermo-mechanical absorber ANSYS calculations, combining both Computational Fluid Mechanics (CFD). The calculations and the calculation process will be discussed as well as the design criteria chosen by the team. The CFD calculations will show that an heat transfer coefficient between the water and the copper part can be estimated as well as the pressure drop through the absorber. Finally, the stress analysis will be emphasized. The type of stresses (tensile, compressive or shear) and their nature (primary or secondary) will be linked to the choice of design criteria

Structural dynamics of light-driven proton pumps.

Bacteriorhodopsin and proteorhodopsin are simple heptahelical proton pumps containing a retinal chromophore covalently bound to helix G via a protonated Schiff base. Following the absorption of a photon, all-trans retinal is isomerized to a 13-cis conformation, initiating a sequence of conformational changes driving vectorial proton transport. In this study we apply time-resolved wide-angle X-ray scattering to visualize in real time the helical motions associated with proton pumping by bacteriorhodopsin and proteorhodopsin. Our results establish that three conformational states are required to describe their photocycles. Significant motions of the cytoplasmic half of helix F and the extracellular half of helix C are observed prior to the primary proton transfer event, which increase in amplitude following proton transfer. These results both simplify the structural description to emerge from intermediate trapping studies of bacteriorhodopsin and reveal shared dynamical principles for proton pumping

Unique Biofilm Signature, Drug Susceptibility and Decreased Virulence in Drosophila through the Pseudomonas aeruginosa Two-Component System PprAB

International audienceBacterial biofilm is considered as a particular lifestyle helping cells to survive hostile environments triggered by a variety of signals sensed and integrated through adequate regulatory pathways. Pseudomonas aeruginosa, a Gram-negative bacterium causing severe infections in humans, forms biofilms and is a fantastic example for fine-tuning of the transition between planktonic and community lifestyles through two-component systems (TCS). Here we decipher the regulon of the P. aeruginosa response regulator PprB of the TCS PprAB. We identified genes under the control of this TCS and once this pathway is activated, analyzed and dissected at the molecular level the PprB-dependent phenotypes in various models. The TCS PprAB triggers a hyper-biofilm phenotype with a unique adhesive signature made of BapA adhesin, a Type 1 secretion system (T1SS) substrate, CupE CU fimbriae, Flp Type IVb pili and eDNA without EPS involvement. This unique signature is associated with drug hyper-susceptibility, decreased virulence in acutely infected flies and cytotoxicity toward various cell types linked to decreased Type III secretion (T3SS). Moreover, once the PprB pathway is activated, decreased virulence in orally infected flies associated with enhanced biofilm formation and dissemination defect from the intestinal lumen toward the hemolymph compartment is reported. PprB may thus represent a key bacterial adaptation checkpoint of multicellular and aggregative behavior triggering the production of a unique matrix associated with peculiar antibiotic susceptibility and attenuated virulence, a particular interesting breach for therapeutic intervention to consider in view of possible eradication of P. aeruginosa biofilm-associated infections

Chopper system for time resolved experiments with synchrotron radiation

10 pagesInternational audienceA chopper system for time resolved pump-probe experiments with x-ray beams from a synchrotron is described. The system has three parts: a water-cooled heatload chopper, a high-speed chopper, and a millisecond shutter. The chopper system, which is installed in beamline ID09B at the European Synchrotron Radiation Facility, provides short x-ray pulses for pump-probe experiments with ultrafast lasers. The chopper system can produce x-ray pulses as short as 200 ns in a continuous beam and repeat at frequencies from 0 to 3 kHz. For bunch filling patterns of the synchrotron with pulse separations greater than 100 ns, the high-speed chopper can isolate single 100 ps x-ray pulses that are used for the highest time resolution. A new rotor in the high-speed chopper is presented with a single pulse (100 ps) and long pulse (10 μs) option. In white beam experiments, the heatload of the (noncooled) high-speed chopper is lowered by a heatload chopper, which absorbs 95% of the incoming power without affecting the pulses selected by the high speed chopper

Timing of SGLT2i initiation after acute myocardial infarction

Abstract Background Pharmacological post-MI treatment is routinely initiated at intensive/cardiac care units. However, solid evidence for an early start of these therapies is only available for dual platelet therapy and statins, whereas data on beta blockers and RAAS inhibitors are heterogenous and mainly limited to STEMI and heart failure patients. Recently, the EMMY trial provided the first evidence on the beneficial effects of SGLT2 inhibitors (SGLT2i) when initiated early after PCI. In patients with type 2 diabetes mellitus, SGLT2i are considered “sick days drugs” and it, therefore, remains unclear if very early SGLT2i initiation following MI is as safe and effective as delayed initiation. Methods and results The EMMY trial evaluated the effect of empagliflozin on NT-proBNP and functional and structural measurements. Within the Empagliflozin group, 22 (9.5%) received early treatment (< 24 h after PCI), 98 (42.2%) within a 24 to < 48 h window (intermediate), and 111 (48.1%) between 48 and 72 h (late). NT-proBNP levels declined by 63.5% (95%CI: − 69.1; − 48.1) in the early group compared to 61.0% (− 76.0; − 41.4) in the intermediate and 61.9% (− 70.8; − 45.7) in the late group (n.s.) within the Empagliflozin group with no significant treatment groups—initiation time interaction (pint = 0.96). Secondary endpoints of left ventricular function (LV-EF, e/e`) as well as structure (LVESD and LVEDD) were also comparable between the groups. No significant difference in severe adverse event rate between the initiation time groups was detected. Conclusion Very early administration of SGLT2i after acute myocardial infarction does not show disadvantageous signals with respect to safety and appears to be as effective in reducing NT-proBNP as well as improving structural and functional LV markers as initiation after 2–3 days