262 research outputs found
Fracture testing of weldments
Fracture toughness testing of welded structure
Using 222 Rn for hydrograph separationin a micro basin (Luxembourg)
In order to obtain information on the hydrological signature of rivers during and after heavy rain events, small
catchment areas are selected as experimental sites. Hydrograph separations based on environmental tracers are
performed. Natural isotopic tracers such as 18O, 2H and particularly 222Rn may help to distinguish the components
dominating the outflow, particularly of 'pre-event waters', 'event waters' and 'post-event waters'. Even with
moderate concentrations in groundwater, radon can be a very sensitive indicator of groundwater input into rivers.
The selected microbasin under investigation is situated in the western part of Luxembourg and belongs to the Attert
River catchment. At chosen points at the basin's outflow radon detectors continuously measure radon activity
in water. The radon monitors are installed together with high precision thermometers, conductivity meters,
flow meters and automatic water samplers for chemical analysis. Besides the continuous measurements, grab
water samples are taken at different locations along the stream, most of them during periods of heavy rain events.
Presented are the results of a one year measurement campaign. During the dry season i.e. during more or less
continuous discharge conditions, the observed mean values do not show substantial variations and can be used
as reference values. Fluctuations of the measured data during rain events are discussed and the interplay between
the different parameters analysed
One-Year Analysis of the Prospective Multicenter SENTRY Clinical Trial: Safety and Effectiveness of the Novate Sentry Bioconvertible Inferior Vena Cava Filter
Purpose
To prospectively assess the Sentry bioconvertible inferior vena cava (IVC) filter in patients requiring temporary protection against pulmonary embolism (PE).
Materials and Methods
At 23 sites, 129 patients with documented deep vein thrombosis (DVT) or PE, or at temporary risk of developing DVT or PE, unable to use anticoagulation were enrolled. The primary end point was clinical success, including successful filter deployment, freedom from new symptomatic PE through 60 days before filter bioconversion, and 6-month freedom from filter-related complications. Patients were monitored by means of radiography, computerized tomography (CT), and CT venography to assess filtering configuration through 60 days, filter bioconversion, and incidence of PE and filter-related complications through 12 months.
Results
Clinical success was achieved in 111 of 114 evaluable patients (97.4%, 95% confidence interval [CI] 92.5%–99.1%). The rate of freedom from new symptomatic PE through 60 days was 100% (n = 129, 95% CI 97.1%–100.0%), and there were no cases of PE through 12 months for either therapeutic or prophylactic indications. Two patients (1.6%) developed symptomatic caval thrombosis during the first month; neither experienced recurrence after successful interventions. There was no filter tilting, migration, embolization, fracture, or caval perforation by the filter, and no filter-related death through 12 months. Filter bioconversion was successful for 95.7% (110/115) at 6 months and for 96.4% (106/110) at 12 months.
Conclusions
The Sentry IVC filter provided safe and effective protection against PE, with a high rate of intended bioconversion and a low rate of device-related complications, through 12 months of imaging-intense follow-up
E-Democracy and the European Public Sphere
The chapter starts with an outline of outstanding recent contributions to the discussion of the EU democratic deficit and the so-called “no demos” problem and the debate about European citizenship and European identity—mainly in the light of insights from the EU crisis. This is followed by reflections on the recent discussion on the state of the mass media-based European public sphere. Finally, the author discusses the state of research on the Internet’s capacity to support the emergence of a (renewed) public sphere, with a focus on options for political actors to use the Internet for communication and campaigning, on the related establishment of segmented issue-related publics as well as on social media and its two-faced character as an enabler as well as a distorting factor of the public sphere. The author is sceptic about the capacities of Internet-based political communication to develop into a supranational (European) public sphere. It rather establishes a network of a multitude of discursive processes aimed at opinion formation at various levels and on various issues. The potential of online communication to increase the responsiveness of political institutions so far is set into practice insufficiently. Online media are increasingly used in a vertical and scarcely in a horizontal or interactive manner of communication
‘Friends call me racist’: Experiences of repercussions from writing comments on newspaper websites
acceptedVersio
Knocking at the brain’s door: intravital two-photon imaging of autoreactive T cell interactions with CNS structures
Since the first applications of two-photon microscopy in immunology 10 years ago, the number of studies using this advanced technology has increased dramatically. The two-photon microscope allows long-term visualization of cell motility in the living tissue with minimal phototoxicity. Using this technique, we examined brain autoantigen-specific T cell behavior in experimental autoimmune encephalitomyelitis, the animal model of human multiple sclerosis. Even before disease symptoms appear, the autoreactive T cells arrive at their target organ. There they crawl along the intraluminal surface of central nervous system (CNS) blood vessels before they extravasate. In the perivascular environment, the T cells meet phagocytes that present autoantigens. This contact activates the T cells to penetrate deep into the CNS parenchyma, where the infiltrated T cells again can find antigen, be further activated, and produce cytokines, resulting in massive immune cell recruitment and clinical disease
Cardiac sodium channelopathies
Cardiac sodium channel are protein complexes that are expressed in the sarcolemma of cardiomyocytes to carry a large inward depolarizing current (INa) during phase 0 of the cardiac action potential. The importance of INa for normal cardiac electrical activity is reflected by the high incidence of arrhythmias in cardiac sodium channelopathies, i.e., arrhythmogenic diseases in patients with mutations in SCN5A, the gene responsible for the pore-forming ion-conducting α-subunit, or in genes that encode the ancillary β-subunits or regulatory proteins of the cardiac sodium channel. While clinical and genetic studies have laid the foundation for our understanding of cardiac sodium channelopathies by establishing links between arrhythmogenic diseases and mutations in genes that encode various subunits of the cardiac sodium channel, biophysical studies (particularly in heterologous expression systems and transgenic mouse models) have provided insights into the mechanisms by which INa dysfunction causes disease in such channelopathies. It is now recognized that mutations that increase INa delay cardiac repolarization, prolong action potential duration, and cause long QT syndrome, while mutations that reduce INa decrease cardiac excitability, reduce electrical conduction velocity, and induce Brugada syndrome, progressive cardiac conduction disease, sick sinus syndrome, or combinations thereof. Recently, mutation-induced INa dysfunction was also linked to dilated cardiomyopathy, atrial fibrillation, and sudden infant death syndrome. This review describes the structure and function of the cardiac sodium channel and its various subunits, summarizes major cardiac sodium channelopathies and the current knowledge concerning their genetic background and underlying molecular mechanisms, and discusses recent advances in the discovery of mutation-specific therapies in the management of these channelopathies
- …