A stereoselective synthesis of functionalized hexahydrocarbazoles was developed based on an unprecedented photoredox‐induced dearomative radical (4+2)‐cyclization/1,4‐addition cascade between ...3‐(2‐iodoethyl)indoles and acceptor‐substituted alkenes. The title reaction simultaneously generates three C−C bonds and one C−H bond, along with three contiguous stereogenic centers. The hexahydro‐1H‐carbazole products are highly valuable intermediates for the synthesis of novel antibiotics, as well as unnatural ring homologues of polycyclic indoline alkaloids.
One photon, four bonds: A photoredox‐induced dearomative radical (4+2)‐cyclization/1,4‐addition cascade with 3‐(2‐iodoethyl)indoles and acceptor‐substituted alkenes enables the synthesis of highly substituted hexahydro‐1H‐carbazoles. This method involves the simultaneous formation of four bonds and three contiguous stereocenters with high stereoselectivity. PC=photocatalyst.
Abstract Objectives The purpose of this study was to analyze the effect of transcatheter aortic valve replacement (TAVR) without versus with prior balloon aortic valvuloplasty (BAV) on the risk of ...cerebral embolization in patients who receive a balloon-expandable valve. Background Avoiding BAV prior to TAVR may simplify the procedure, but the risk of cerebral embolization is currently unknown. Methods A total of 87 consecutive high surgical-risk patients with no contraindications for diffusion-weighted magnetic resonance imaging (DW-MRI) were enrolled. Thirty-two patients received a balloon-expandable aortic valve with and 55 patients without BAV. The incidence, number, and volume of new ischemic lesions in DW-MRI performed 2 to 7 days after TAVI were evaluated. Results Mean age (83.8 ± 5.2 years vs. 82.9 ± 6.8 years) and sex (43.8% vs. 52.7% male) of the patients with versus without BAV, respectively, as well as other demographic and hemodynamic data were not significantly different between both groups. The procedural success rate was 93.5% with and 98.2% without BAV, and procedure duration and contrast volume were significantly lower without BAV. The incidence of new cerebral ischemic lesions in the total cohort was 66.7%. Compared with patients with BAV, those without BAV had a significantly higher total volume of cerebral ischemic lesions (235.4 ± 331.4 mm3 vs. 89.5 ± 128.2 mm3 ; p = 0.01). Conclusions The implantation of a balloon-expandable aortic valve without versus with prior BAV, although performed with a shorter procedure time and lower contrast volume, is associated with a significantly higher volume of cerebral ischemic lesions.
Very similar to functional mitral regurgitation (MR), TR is mainly due to ventricular enlargement, annulus dilation, and loss of leaflet coaptation. ...percutaneous mitral valve repair therapy might ...potentially also be applied for TR. ...she was deemed a suitable candidate for the percutaneous mitral valve repair procedure.
We investigate the construction of black holes and black strings in vacuum plane wave spacetimes using the method of matched asymptotic expansions. We find solutions of the linearised equations of ...motion in the asymptotic region for a general source on a plane wave background. We observe that these solutions do not satisfy our previously defined conditions for being asymptotically plane wave. Hence, the space of asymptotically plane wave solutions is restricted. We consider the solution in the near region, treating the plane wave as a perturbation of a black object, and find that there is a regular black string solution but no regular black hole solution.
The impact of Pulsed Electric Fields (PEF) on the peeling ability of different fruits and vegetables in particular tomatoes, peaches, peppers, and oranges were investigated. Samples were exposed to a ...fixed electric field strength of 2.15 kV/cm. The specific energy ranged from 0.6 kJ/kg to 50.3 kJ/kg. The treated raw materials were analysed regarding to the peeling ability, skin size and weight and firmness. The best result for tomatoes at a specific energy of 1.2 kJ/kg induced a high score of peeling ability that led to less product loss and could therefore increase the yield by 33.84%–41.53% compared to untreated samples. Moreover, an increased skin size by a factor of 3.7 was observed. However, PEF had no significant impact on peeling ability of oranges, peppers, and peaches. Although oranges showed an improvement in peeling ability by up to 32%, this cannot be traced back to the PEF treatment. The different properties and structures of the raw materials were discussed and provided indications about the limitation of PEF.
•Pulsed Electric Fields (PEF) improves peeling results of tomatoes significantly.•PEF induces a water accumulation under the skin of tomatoes.•Low intensity of 1.2 kJ/kg is sufficient to gain optimal results for tomato peeling.•PEF does not affect the hemicellulose and pectic network of fruits and vegetables.•Albedo content significantly influences the peeling results of oranges, not PEF.
Objective
To evaluate the risk for brain lesions in valve in valve (VIV)‐transcatheter aortic valve replacement (TAVR) compared to native valve procedures (NV‐TAVR).
Background
TAVR is associated ...with the risk of stroke and a high incidence of brain lesions in diffusion‐weighted magnetic resonance imaging (DW‐MRI). The risk in VIV procedures is unknown.
Methods
Patients were included, if they received a Sapien‐3 or an Evolut‐R valve for an NV‐TAVR or VIV‐TAVR and a DW‐MRI within 3–5 days after the procedure.
Results
Two hundred nine patients had NV‐TAVR and 41 patients had VIV‐TAVR.
The VIV group was significantly younger (mean 82.3 vs. 74.7 years old, p < .001) but had higher mean EuroSCORE II (4.8 vs. 7.8, p < .001).
Predilatation was significantly more common with native valve (39% vs. 2%, p < .01), postdilatation rate was lower in VIV but without statistical significance (17% vs. 7%, p = .110).
Combined in‐hospital safety outcome was comparable 13(6.6%) vs. 5(12.2%), p = .205. Any stroke was documented in four (0.5%) patients after native valve and in one (2.4%) after VIV‐TAVR.
New DW‐MRI brain lesions were significantly more often found in patients with native valves 153(73.2%) vs. 21(51.2%), p = .005, mean number of new lesions was also higher with native valve (2.8 ± 3.2 vs. 1.0 ± 1.4, p < .001).
Forward stepwise of logistic regression found age and post dilatation significant predictors of new MRI lesions.
Conclusions
Compared to native valves, VIV procedures were associated with lower incidence and number of brain lesions according to DW‐MRI; these were explained by lower patients' age and lower rate of postdilatation.
Abstract
A stereoselective synthesis of functionalized hexahydrocarbazoles was developed based on an unprecedented photoredox‐induced dearomative radical (4+2)‐cyclization/1,4‐addition cascade ...between 3‐(2‐iodoethyl)indoles and acceptor‐substituted alkenes. The title reaction simultaneously generates three C−C bonds and one C−H bond, along with three contiguous stereogenic centers. The hexahydro‐1
H
‐carbazole products are highly valuable intermediates for the synthesis of novel antibiotics, as well as unnatural ring homologues of polycyclic indoline alkaloids.
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