Observations of stellar kinematics, gas dynamics and masers around galactic
nuclei have now firmly established that many galaxies host central supermassive
black holes (SMBHs) with masses in the ...range $10^6 \sim 10^9$M$_{\odot}$.
However, how these SMBHs formed is not well understood. One reason for this
situation is the lack of observations of intermediate-mass BHs (IMBHs), which
could bridge the gap between stellar-mass BHs and SMBHs. Recently, this missing
link (i.e., an IMBH) has been found in observations made by the ASCA and the
Chandra of the central region of the starburst galaxy M82 \citep{MT99, PG99,
MT01, Ka01}. Subsequent observations by SUBARU have revealed that this IMBH
apparently coincides with a young compact star cluster. Based on these
findings, we suggest a new formation scenario for SMBHs. In this scenario,
IMBHs first form in young compact star clusters through runaway merging of
massive stars. While these IMBHs are forming, the host star clusters sink
toward the galactic nucleus through dynamical friction, and upon evaporation
deposit their IMBHs near the galactic center. The IMBHs then form binaries and
eventually merge via gravitational radiation, forming an SMBH.
Observations of stellar kinematics, gas dynamics and masers around galactic nuclei have now firmly established that many galaxies host central supermassive black holes (SMBHs) with masses in the ...range \(10^6 \sim 10^9\)M\(_{\odot}\). However, how these SMBHs formed is not well understood. One reason for this situation is the lack of observations of intermediate-mass BHs (IMBHs), which could bridge the gap between stellar-mass BHs and SMBHs. Recently, this missing link (i.e., an IMBH) has been found in observations made by the ASCA and the Chandra of the central region of the starburst galaxy M82 \citep{MT99, PG99, MT01, Ka01}. Subsequent observations by SUBARU have revealed that this IMBH apparently coincides with a young compact star cluster. Based on these findings, we suggest a new formation scenario for SMBHs. In this scenario, IMBHs first form in young compact star clusters through runaway merging of massive stars. While these IMBHs are forming, the host star clusters sink toward the galactic nucleus through dynamical friction, and upon evaporation deposit their IMBHs near the galactic center. The IMBHs then form binaries and eventually merge via gravitational radiation, forming an SMBH.
ObjectiveThe association between a combined anaemia and renal failure index and 1-year prognosis of patients undergoing transcatheter aortic valve implantation (TAVI) is unexplored. We aimed to ...investigate a simple risk score in patients undergoing TAVI.MethodsA total of 469 consecutive patients undergoing TAVI between 2015 and 2021 were enrolled. After excluding patients undergoing dialysis, the remaining 458 patients were classified according to three tertiles of the serum haemoglobin-to-creatinine (Hgb/Cr) ratio 1 day before TAVI. The primary clinical outcome measure was all-cause mortality and heart failure hospitalisation 1 year after TAVI.ResultsIn the first, second and third tertiles, the 1-year cumulative incidence of all-cause mortality was 16.9% versus 7.2% versus 2.0%, respectively (p<0.01), and that of heart failure hospitalisation was 10.7% versus 3.4% versus 0.7%, respectively (p<0.01). The indexes of the area under the curve of the Hgb/Cr ratio for all-cause mortality and heart failure hospitalisation 1 year after TAVI were both 0.73. Cut-off values were 10.1 for all-cause mortality 1 year after TAVI (OR, 4.78; 95% CI 2.43 to 9.74; p<0.01) and 10.4 for heart failure hospitalisation 1 year after TAVI (OR, 5.3; 95% CI 2.21 to 14.1; p<0.01). In the multivariate analysis, the Hgb/Cr ratio was an independent predictor of all-cause mortality and heart failure hospitalisation 1 year after TAVI.ConclusionsHgb/Cr ratio calculation 1 day before TAVI may help predict midterm all-cause mortality and heart failure hospitalisation in patients with severe aortic valve stenosis undergoing TAVI.Trial registration number4143 (The Institutional Review Board of Kurashiki Central Hospital)
Point-by-point catheter ablation is an established treatment for drug-refractory paroxysmal atrial fibrillation (PAF). However, it is time consuming, requires excellent technique to achieve complete ...pulmonary vein (PV) isolation, and is associated with severe complications.
The purpose of this study was to evaluate the safety and effectiveness of a HotBalloon ablation (HBA) compared with antiarrhythmic drug therapy (ADT) for the treatment of PAF.
A prospective multicenter randomized controlled study was conducted in Japan. Patients with symptomatic PAF refractory to antiarrhythmic drugs (Class I to IV) were randomized to HBA or ADT at a 2:1 ratio and assessed for effectiveness in a comparable 9-month follow-up period.
A total of 100 patients in the HBA group and 43 patients in the ADT group received treatment at 17 sites. HBA procedure produced acute complete PV isolation in 98.0% (392 of 400) of the PVs and in 93.0% (93 of 100) of patients in the HBA group. The chronic success rates after the 9-month effective evaluation period were 59.0% in the HBA group (n = 100) and 4.7% in the ADT group (n = 43; p < 0.001). The incidence of major complications was 11.2% (15 of 134 patients). The incidences of PV stenosis (>70%) and transient phrenic nerve injury were 5.2% and 3.7%, respectively. The mean fluoroscopy time was 49.4 ± 26.6 min (n = 134), and the mean procedure duration was 113.9 ± 31.9 min (n = 133).
This study demonstrates the superiority of HBA compared with ADT for treatment of patients with PAF, and a favorable safety profile.
This study investigated the effect of fuel injection pressure (20–80MPa) on atomization and combustion characteristics using a stationary combustor with an intermittent supply of liquid fuel. In the ...atomization experiments, spray tip penetration and spray width increased, and the Sauter mean diameter of droplets decreased with an increase in the fuel injection pressure. In the combustion experiments, the OH emission intensity and combustion gas temperature upstream of the furnace increased with the fuel injection pressure, whereas nitrogen oxides emissions were reduced. The results demonstrate that high-pressure pulse spray combustion can reduce NOX emissions and enhance the combustion load by an increase in the fuel injection pressure.
•Combustion experiments with an intermittent supply of liquid fuel were conducted.•Combustion gas temperature was related to spray tip penetration and width.•Nitrogen oxides emissions decreased with an increase in fuel injection pressure.
Abstract Background Point-by-point catheter ablation is an established treatment for drug-refractory paroxysmal atrial fibrillation (PAF). However, it is time consuming, requires excellent technique ...to achieve complete pulmonary vein (PV) isolation, and is associated with severe complications. Objectives The purpose of this study was to evaluate the safety and effectiveness of a HotBalloon ablation (HBA) compared with antiarrhythmic drug therapy (ADT) for the treatment of PAF. Methods A prospective multicenter randomized controlled study was conducted in Japan. Patients with symptomatic PAF refractory to antiarrhythmic drugs (Class I to IV) were randomized to HBA or ADT at a 2:1 ratio and assessed for effectiveness in a comparable 9-month follow-up period. Results A total of 100 patients in the HBA group and 43 patients in the ADT group received treatment at 17 sites. HBA procedure produced acute complete PV isolation in 98.0% (392 of 400) of the PVs and in 93.0% (93 of 100) of patients in the HBA group. The chronic success rates after the 9-month effective evaluation period were 59.0% in the HBA group (n = 100) and 4.7% in the ADT group (n = 43; p < 0.001). The incidence of major complications was 11.2% (15 of 134 patients). The incidences of PV stenosis (>70%) and transient phrenic nerve injury were 5.2% and 3.7%, respectively. The mean fluoroscopy time was 49.4 ± 26.6 min (n = 134), and the mean procedure duration was 113.9 ± 31.9 min (n = 133). Conclusions This study demonstrates the superiority of HBA compared with ADT for treatment of patients with PAF, and a favorable safety profile.
PDF
