An Alternative Method to Deduce Bubble Dynamics in Single Bubble Sonoluminescence Experiments

In this paper we present an experimental approach that allows to deduce the important dynamical parameters of single sonoluminescing bubbles (pressure amplitude, ambient radius, radius-time curve) The technique is based on a few previously confirmed theoretical assumptions and requires the knowledge of quantities such as the amplitude of the electric excitation and the phase of the flashes in the acoustic period. These quantities are easily measurable by a digital oscilloscope, avoiding the cost of expensive lasers, or ultrafast cameras of previous methods. We show the technique on a particular example and compare the results with conventional Mie scattering. We find that within the experimental uncertainties these two techniques provide similar results.Comment: 8 pages, 5 figures, submitted to Phys. Rev.

Studies of \u3csup\u3e54,56\u3c/sup\u3eFe Neutron Scattering Cross Sections

Elastic and inelastic neutron scattering differential cross sections and γ-ray production cross sections have been measured on 54,56Fe at several incident energies in the fast neutron region between 1.5 and 4.7 MeV. All measurements were completed at the University of Kentucky Accelerator Laboratory (UKAL) using a 7-MV Model CN Van de Graaff accelerator, along with the neutron production and neutron and γ-ray detection systems located there. The facilities at UKAL allow the investigation of both elastic and inelastic scattering with nearly mono-energetic incident neutrons. Time-of-flight techniques were used to detect the scattered neutrons for the differential cross section measurements. The measured cross sections are important for fission reactor applications and also for testing global model calculations such as those found at ENDF, since describing both the elastic and inelastic scattering is important for determining the direct and compound components of the scattering mechanism. The γ-ray production cross sections are used to determine cross sections to unresolved levels in the neutron scattering experiments. Results from our measurements and comparisons to model calculations are presented

Neutron Scattering Cross Section Measurements for \u3csup\u3e56\u3c/sup\u3eFe

Elastic and inelastic differential cross sections for neutron scattering from 56Fe have been measured for several incident energies from 1.30 to 7.96 MeV at the University of Kentucky Accelerator Laboratory. Scattered neutrons were detected using a C6D6 liquid scintillation detector using pulse-shape discrimination and time-of-flight techniques. The deduced cross sections have been compared with previously reported data, predictions from evaluation databases ENDF, JENDL, and JEFF, and theoretical calculations performed using different optical model potentials using the TALYS and EMPIRE nuclear reaction codes. The coupled-channel calculations based on the vibrational and soft-rotor models are found to describe the experimental (n,n0) and (n,n1) cross sections well

Prognostic impact of implantable cardioverter defibrillators and associated adverse events in patients with continuous flow left ventricular assist devices

ObjectivesImplantation of implantable cardioverter defibrillators (ICD) reduces the risk of all-cause mortality in symptomatic heart failure (HF) patients with severe left ventricular (LV) dysfunction. Nevertheless, the prognostic impact of ICD therapy in continuous flow left ventricular assist device (LVAD) recipients remains controversial.Methods162 consecutive HF patients, who underwent LVAD implantation at our institution between 2010 and 2019, were categorized according to the presence (n = 94, ICD-group) or absence (n = 68, Control-group) of ICDs. Apart from clinical baseline and follow-up parameters, adverse events (AEs) related to ICD therapy and overall survival rates were retrospectively analyzed.ResultsOut of 162 consecutive LVAD recipients 79 patients (48.8%) were preoperatively categorized as Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile ≤2. The prevalence of severe HF symptoms and preoperative use of short-term circulatory support devices (54.4% vs. 13.8%, p < 0.001) was higher within the Control-group, although baseline severity of LV and RV dysfunction was similar. Apart from an increased prevalence of perioperative right heart failure (RHF) within the Control-group (45.6% vs. 17.0%; p < 0.001), procedural characteristics and perioperative outcome were similar. Overall-survival during a median follow-up of 14 (3.0–36.5) months was similar within both groups (p = 0.46). During the first 2 years after LVAD implantation 53 ICD-related AEs occurred within the ICD-group. Thereof, lead-dysfunction occurred in 19 patients and unplanned ICD-reintervention in 11 patients. Furthermore, in 18 patients appropriate shocks without loss of consciousness occurred, whereas inappropriate shocks occurred in 5 patients.ConclusionICD therapy in LVAD recipients was not associated with a survival benefit or reduced morbidity after LVAD implantation. Conservative ICD-programming seems to be justified to avoid ICD-related complications and „awake shocks” after LVAD implantation

Extreme Ultraviolet Reflective Grating Characterization and Simulationsfor the Aspera SmallSat Mission

The Aspera SmallSat mission is designed to detect and map the warm-hot gaseous component of the halos of nearby galaxies through long-slit spectroscopy of the ionized O VI emission line (103.2 nm) for the first time. The Aspera Rowland circle type spectrograph uses a toroidal grating coated with a multilayer film consisting of aluminum, lithium fluoride, and magnesium fluoride capping to optimize reflectivity in the extreme ultraviolet (EUV) waveband from 103 to 104nm. We discuss the grating characterization test setup at the University of Arizona (UA), which will validate the multilayer coating and grating efficiency in a UV vacuum chamber. We also simulate the reflectivity of the multilayer thin film coating using IMD IDL software to compare simulated results with measured reflectivity. Additionally, non-sequential ray trace simulations and 3D CAD modeling are used for verification of the test setup. Finally, the implications of the differences between the measured and simulated reflectivity and grating efficiencies are considered, including impact to the mission

Signature-Tagged Mutagenesis in a Chicken Infection Model Leads to the Identification of a Novel Avian Pathogenic Escherichia coli Fimbrial Adhesin

The extraintestinal pathogen, avian pathogenic E. coli (APEC), known to cause systemic infections in chickens, is responsible for large economic losses in the poultry industry worldwide. In order to identify genes involved in the early essential stages of pathogenesis, namely adhesion and colonization, Signature-tagged mutagenesis (STM) was applied to a previously established lung colonization model of infection by generating and screening a total of 1,800 mutants of an APEC strain IMT5155 (O2:K1:H5; Sequence type complex 95). The study led to the identification of new genes of interest, including two adhesins, one of which coded for a novel APEC fimbrial adhesin (Yqi) not described for its role in APEC pathogenesis to date. Its gene product has been temporarily designated ExPEC Adhesin I (EA/I) until the adhesin-specific receptor is identified. Deletion of the ExPEC adhesin I gene resulted in reduced colonization ability by APEC strain IMT5155 both in vitro and in vivo. Furthermore, complementation of the adhesin gene restored its ability to colonize epithelial cells in vitro. The ExPEC adhesin I protein was successfully expressed in vitro. Electron microscopy of an afimbriate strain E. coli AAEC189 over-expressed with the putative EA/I gene cluster revealed short fimbrial-like appendages protruding out of the bacterial outer membrane. We observed that this adhesin coding gene yqi is prevalent among extraintestinal pathogenic E. coli (ExPEC) isolates, including APEC (54.4%), uropathogenic E. coli (UPEC) (65.9%) and newborn meningitic E. coli (NMEC) (60.0%), and absent in all of the 153 intestinal pathogenic E. coli strains tested, thereby validating the designation of the adhesin as ExPEC Adhesin I. In addition, prevalence of EA/I was most frequently associated with the B2 group of the EcoR classification and ST95 complex of the multi locus sequence typing (MLST) scheme, with evidence of a positive selection within this highly pathogenic complex. This is the first report of the newly identified and functionally characterized ExPEC adhesin I and its significant role during APEC infection in chickens

Minimal access median sternotomy for aortic valve replacement in elderly patients

BACKGROUND: We report our clinical experience with a approach for aortic valve replacement (AVR) via minimal access skin incision and complete median sternotomy. This approach was used in patients with higher age and multiple co-morbidities, facilitating an easy access with short bypass and cross clamp times. It was especially performed in patients asking for an excellent cosmetic result, who did not qualifying for minimally-invasive AVR via partial upper sternotomy. METHODS: AVR via minimal-access median sternotomy, was performed in 58 patients between 01/2009 and 11/2011. Intra- and postoperative data including cross clamp time, cardiopulmonary bypass time, mortality, stroke, pacemaker implantation, re-operation for bleeding, ventilation time, ICU and hospital stay, wound infection, sternal dehiscence or fracture and 30 day mortality were collected. RESULTS: Mean patients age was 76.1 +/−9.4 years, 72% were female. Minimal-access AVR could be performed with a mean length of midline skin incision of 7.8 cm. Aortic cross-clamping time was 54.6 +/−6.3 min, cardiopulmonary bypass time 71.2+/−11.3 min and time of surgery 154.1 +/−26.8 min. Re-operation for bleeding had to be performed in 1 case (1.7%). There were no strokes or pacemaker implantations needed. Mean ventilation time was 4.5 h, ICU stay was 2 days and mean length of hospital stay was 6 days. 6 months follow up showed mortality of 0% and no sternal dehiscence or wound infection was observed. CONCLUSION: Minimal-access AVR via complete median sternotomy can be performed safely,in this elderly patient cohort without adding additional operative risk compared to conventional AVR. By avoidiance of large skin incisions this approach combines excellent cosmetic results with fast surgery time and excellent postoperative recovery

withdrawn 2017 hrs ehra ecas aphrs solaece expert consensus statement on catheter and surgical ablation of atrial fibrillation

n/

An Evaluation of the Bank's Non-Sovereign Operations with Sub-National Entities: 2007-2010

This evaluation examines the IDB's non-sovereign operations with sub-national entities during the 2007-2010 period. The delivery of loans to sub-national borrowers in this period was modest, not even near breaching the one-third ceiling. Attention to the sub-national sector is important in Latin America, because effective public service delivery is critical for poverty reduction, low gross capital formation is hindering development in the region, and decentralization has increasingly placed investment decisions for infrastructure services at the sub-national level. This presents an opportunity for the IDB, as, compared to peer multilaterals, it has a limited share in this sector. Therefore, OVE advises to: (i) further understand the potential market for sub-national lending, analyzing and mapping eligible and currently excluded sub-national entities in client countries, using alternative policy scenarios for both sovereign guaranteed and non-sovereign guaranteed operations; (ii) review the guidelines and practices of peer multilaterals to determine the desirability and feasibility of emulating them; and (iii) propose changes to existing policy and guidelines such that the IDB can better serve currently excluded sub-national enterprises through non-sovereign guaranteed lending.