35 research outputs found
GW190814: gravitational waves from the coalescence of a 23 solar mass black hole with a 2.6 solar mass compact object
We report the observation of a compact binary coalescence involving a 22.2â24.3 Me black hole and a compact object with a mass of 2.50â2.67 Me (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGOâs and Virgoâs third observing run on 2019 August 14 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of - + 241 45
41 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal mass ratio yet measured with gravitational waves, - + 0.112 0.009 0.008, and its secondary component is either the lightest black hole or the heaviest neutron star ever discovered in a double compact-object system. The
dimensionless spin of the primary black hole is tightly constrained to ïżœ0.07. Tests of general relativity reveal no measurable deviations from the theory, and its prediction of higher-multipole emission is confirmed at high confidence. We estimate a merger rate density of 1â23 Gpcâ3 yrâ1 for the new class of binary coalescence sources
that GW190814 represents. Astrophysical models predict that binaries with mass ratios similar to this event can form through several channels, but are unlikely to have formed in globular clusters. However, the combination of mass ratio, component masses, and the inferred merger rate for this event challenges all current models of the formation and mass distribution of compact-object binaries
Advances in thermal laser separation: Process monitoring in a kerf-free laser-based cutting technology to ensure high yield
Thermal Laser Separation (TLS) is an ablation free and therefore kerf free laser based cutting technology. This novel dicing technology is utilized to separate microelectronic devices on semiconductor wafers. In order to broaden the use of TLS method towards smaller chips and new materials on the one side and towards an advanced process monitoring on the other side, a novel contact-free measuring method for monitoring the TLS process has been developed. This new method is based on heating the semiconductor wafer with a near-infrared (NIR) laser and analyzing the subsequent temperature gradients induced by heat diffusion with contact-less temperature measurement. Thus, the TLS-crack can be detected due to its isolating effect to heat flux. The feasibility of the method is presented and the influence of parameters like sample size, distance to the TLS-crack and the laser setup in the measurements is reported
Direct minimally invasive intramyocardial injection of bone marrow-derived AC133+stem cells in patients with refractory ischemia : preliminary results
Background: Bone marrow-derived stem cells (BMSC) may represent a viable option for patients with myocardial ischemia refractory to conventional treatments. Material and Methods: In 5 patients (4 males and 1 female, mean age 64 \ub1 8 years) with untreatable angina pectoris (Canadian Cardiovascular Society Class III/IV), myocardial segments with stress-induced ischemia as assessed by gated single-photon emission computed tomography were injected with 4 to 12 million CD133+ BMSC. Cells were injected into the myocardium (2 anterior, 2 lateral, 1 inferior wall) through minimally invasive approaches (left minithoracotomy [n = 4] and subdiaphragmatic approach [n = 1]). At baseline, at 6 months and at 1 year of follow-up, an exercise test, gated single-photon emission computed tomography (SPECT), 2-D echocardiography and coronary angiography were performed to assess exercise capacity, myocardial perfusion, LV function and coronary anatomy. Results: Intramyocardial injection of autologous CD133+ BMSC cells was safe. No early or long-term complications were observed. After an average of 3.8 weeks from cell inoculation, all patients experienced a significant improvement of CCS class (from 3.8 to 1.8 at 6 months) and serial SPECT documented improvements of rest and stress perfusion in the injected territories at 6 months from operation. In 3 cases, coronary angiography showed an increase in the collateral score of the target areas. Clinical improvements still persist unchanged in 4 out of 5 cases at a mean of 36.5 months postoperatively. Conclusions: After stand-alone BMSC transplantation for refractory myocardial ischemia, we observed long-term clinical and perfusion improvements in the absence of adverse events
Pharmacologic inhibition of hypoxia-inducible factor (HIF)-hydroxylases ameliorates allergic contact dermatitis
Background
When an immune cell migrates from the bloodstream to a site of chronic inflammation, it experiences a profound decrease in microenvironmental oxygen levels leading to a state of cellular hypoxia. The hypoxiaâinducible factorâ1α (HIFâ1α) promotes an adaptive transcriptional response to hypoxia and as such is a major regulator of immune cell survival and function. HIF hydroxylases are the family of oxygenâsensing enzymes primarily responsible for conferring oxygen dependence upon the HIF pathway.
Methods
Using a mouse model of allergic contact dermatitis (ACD), we tested the effects of treatment with the pharmacologic hydroxylase inhibitor DMOG, which mimics hypoxia, on disease development.
Results
Reâexposure of sensitized mice to 2,4âdinitrofluorobenzene (DNFB) elicited inflammation, edema, chemokine synthesis (including CXCL1 and CCL5) and the recruitment of neutrophils and eosinophils. Intraperitoneal or topical application of the pharmacologic hydroxylase inhibitors dymethyloxalylglycine (DMOG) or JNJ1935 attenuated this inflammatory response. Reduced inflammation was associated with diminished recruitment of neutrophils and eosinophils but not lymphocytes. Finally, hydroxylase inhibition reduced cytokineâinduced chemokine production in cultured primary keratinocytes through attenuation of the JNK pathway.
Conclusion
These data demonstrate that hydroxylase inhibition attenuates the recruitment of neutrophils to inflamed skin through reduction of chemokine production and increased neutrophilic apoptosis. Thus, pharmacologic inhibition of HIF hydroxylases may be an effective new therapeutic approach in allergic skin inflammation.This work was funded by Science Foundation Ireland grants to Cormac Taylor and Martin Steinhoff and a grant from the European Union (ERACoSYSMed) to Cormac Taylor and Martin Schneider. Moritz Strowitzki receives funding from the German Research Foundation (DFG; STR 1570/1-1) and the Braun Foundation (Braun; BBSTD18/00018).Scopu