Self-expanding transcatheter aortic valve replacement in patients with extremely horizontal aortas.

OBJECTIVES: To evaluate the feasibility of self-expanding transcatheter aortic valve replacement (TAVR) in patients with aortic stenosis and extremely horizontal aortas (aortic angulation ≥70°). BACKGROUND: As TAVR using a self-expanding prosthesis is an off-label treatment for patients with extremely horizontal aortas, these patients are often excluded from randomized controlled trials involving self-expanding TAVR. METHODS: This study enrolled 27 consecutive patients with extremely horizontal aortas who underwent self-expanding TAVR for severe aortic stenosis. RESULTS: The patients' average age was 76.4 years, with a median Society of Thoracic Surgeons score of 4.53%. The device success and 30-day mortality rates were 66.7% and 7.4%, respectively. The sinotubular junction (STJ) was significantly smaller in the device success group (p = 0.001). The receiver operating characteristic curve analysis found that the area under the curve was 0.907 (95% confidence interval: 0.790-1.000, p = 0.001), validating the association between STJ diameter and device success. An optimal cutoff of 33.6 mm was determined using the Youden index, with a sensitivity and specificity of 88.9% and 77.8%, respectively. The device success rate was significantly higher (93.3% vs. 33.3%, p = 0.003) in patients with STJ diameters ≤33.6 mm (n = 15). In the subgroup analyses, severe valve calcification (n = 9) was associated with a higher incidence of moderate or severe paravalvular leakage (44.0% vs. 0%, p = 0.008), while a higher rate of second valve implantation (60.0% vs. 9.1%, p = 0.030) was found in patients with less than moderate valve calcification (n = 5). CONCLUSION: Self-expanding TAVR could be suitable for patients with extremely horizontal aortas after careful preoperative evaluation.

Validation of a novel staging classification system based on the extent of cardiac damage among Chinese patients after transcatheter aortic valve replacement: A single-center retrospective study.

OBJECTIVES: We aimed to validate a novel staging system for aortic stenosis (AS) in a Chinese patient cohort undergoing transcatheter aortic valve replacement (TAVR), and to compare this classification system to the traditional Society of Thoracic Surgeons (STS) score for TAVR risk stratification. BACKGROUND: A novel staging system for AS based on the extent of cardiac damage upon echocardiography was recently proposed. METHODS: Patients were prospectively enrolled into the Transcatheter Aortic Valve Replacement Single Center Registry in Chinese Population and analyzed retrospectively following additional exclusion criteria. On the basis of echocardiographic findings of cardiac damage, patients were classified into five stages (0-4). RESULTS: A total of 427 patients were included in the current analysis. Forty-eight deaths occurred during a median follow-up of 730 days following TAVR. The staging system showed a statistically significant association between cardiac damage and all-cause mortality; advanced stages were associated with higher mortality. In a multivariate-adjusted Cox proportional hazards regression model, stage and STS scores served as risk factors for 2-year mortality. Each increment in the staging class was associated with an increased risk of mortality (hazard ratio, 1.275; 95% confidence interval [CI], 1.052-1.545). Receiver operating characteristic (ROC) curves were plotted for stage (area under the curve, 0.644; 95% CI, 0.562-0.725) and STS score (0.661; 0.573-0.749), and with no statistically significant differences between ROC curves (p = 0.920). CONCLUSIONS: We validated a novel staging system as a key risk factor for 2-year mortality in a Chinese TAVR patient cohort. Efficacy for risk stratification was comparable to the STS score.

Strategic measurement for the axis-orientation and electro-optic coefficient of BaTiO3 crystal thin-film grown on MgO crystal with polarization modulations: erratum.

In this erratum the set of Eqs. (2a) and (2b), Eqs. (4) and (5), and the corresponding figure and values in the text of Opt. Lett.45, 4215 (2019)OPLEDP0146-959210.1364/OL.44.004215 have been updated.

Strategic measurement for the axis orientation and electro-optic coefficient of BaTiO3 crystal thin film grown on MgO crystal with polarization modulations.

BaTiO3 crystal thin film has been investigated to realize electro-optic (EO) devices due to its ultrahigh EO effect, but not much research has been focused on the correct axis orientation and EO coefficient. In this Letter, with a BaTiO3 crystal film grown by pulse laser deposition technique on ⟨100⟩ MgO crystal substrate, an embedded device configuration having the two-step etched waveguide/electrode scheme is designed to reach a high optic-electrical field interaction efficiency, and a 45° outside electric field with an in-plane axis is set to fit the possibility of the a-axis or c-axis orientation of the BaTiO3 crystal film. Then, through a poling process to the sample, the 1π, 2π, and 3π EO modulations of linear polarization are implemented at 4.9, 9.3, and 11.8 V, respectively, and a decremental voltage period is found. Thereby, a c-axis oriented BaTiO3 crystal film is determined, so that the nonlinear modulation equation is exploited. Finally, with an overlap of 1π, 2π, and 3π modulations, the coherent EO coefficient r51 and birefringence of 606 pm/V and -0.0215 are obtained, resulting in one (Vπ)2L value of 68 (V2·mm).

Cerebral ischemic injury after transcatheter aortic valve replacement in patients with pure aortic regurgitation. / ç»å¯¼ç®¡ä¸»åŠ¨è„‰ç“£ç½®æ¢æœ¯æ²»ç–—å•çº¯ä¸»åŠ¨è„‰ç“£åæµæ‚£è€ æœ¯åŽè„‘æŸä¼¤.

Considering the surgical risk stratification for patients with severe calcific aortic stenosis (AS), transcatheter aortic valve replacement (TAVR) is a reliable alternative to surgical aortic valve replacement (SAVR) (Fan et al., 2020, 2021; Lee et al., 2021). Despite the favorable clinical benefits of TAVR, stroke remains a dreaded perioperative complication (Auffret et al., 2016; Kapadia et al., 2016; Kleiman et al., 2016; Huded et al., 2019). Ischemic overt stroke, identified in 1.4% to 4.3% of patients in TAVR clinical practice, has been associated with prolonged disability and increased mortality (Auffret et al., 2016; Kapadia et al., 2016; Levi et al., 2022). The prevalence of hyperintensity cerebral ischemic lesions detected by diffusion-weighted magnetic resonance imaging (DW-MRI) was reported to be about 80%, which is associated with impaired neurocognitive function and vascular dementia (Vermeer et al., 2003; Barber et al., 2008; Kahlert et al., 2010).

Mid-infrared spectroscopy of hemispherical water droplets.

As an important component of atmospheric aerosols, water is profoundly related with aerosol hygroscopicity and provides a medium for atmospheric heterogeneous reactions. The quantitative analysis of water content in aerosol droplets is instrumental to understanding atmospheric chemistry, as well as to addressing the related environmental issues, such as air pollution and climate change. Fourier transform infrared (FTIR) spectroscopy has been widely adopted to quantify the amount of water content in atmospheric aerosols, which is based on the absorbance of OH functional group in proportion to water content. However, in the OH stretching vibration band around 3400 cm-1, spectral distortions may occur, making a quantitative analysis impossible. In addressing this issue, here we put forth a model to simulate the FTIR absorption of hemispherical water droplets, along with a quantitative description of the spectral distortion. Our model prediction was benchmarked with the microscopic-FTIR experiments conducted on sodium sulfate droplets, and good agreements between theoretical and experimental results were found. We observed that the absorbance spanning across the mid-wavenumber infrared region increases with water absorption coefficients; while such an increasing trend was not seen in the 3400 cm-1 band. We speculate that the spectral saturated absorption is related to the absorption coefficient of water and the ratio of the projected area of droplets to the aperture area. In addition, the effects of droplet size and number density on the absorption spectra were investigated. The waveband range of the saturated absorption broadens with an increase in droplet radius. On the other hand, as the number density of water droplets increases, the absorption at 3400 cm-1 is enhanced, and the characteristic peak of condensed water becomes increasingly sharper, asymptotic to the typical infrared spectra of water collected by the pressing method.

Anemia and risk of periprocedural cerebral injury detected by diffusion-weighted magnetic resonance imaging in patients undergoing transcatheter aortic valve replacement.

BACKGROUND: Anemia is prevalent in patients undergoing transcatheter aortic valve replacement (TAVR) and has been linked to impaired outcomes after the procedure. Few studies have evaluated the impact of anemia and new ischemic lesions post TAVR. METHODS: We prospectively enrolled 158 patients who received TAVR in our center. Anemia was defined according to the World Health Organization criteria as hemoglobin <12 g/dL in women and <13 g/dL in men. All patients underwent diffusion-weighted magnetic resonance imaging (DW-MRI) procedure before and within 4-7 days after TAVR. RESULTS: Anemia was present in 85 (53.8%) patients who underwent TAVR, and 126 (79.7%) patients had 718 new DW-MRI positive lesions with a mean of 4.54±5.26 lesions per patient. The incidence of new ischemic lesions was 81.2% in patients with anemia versus 78.1% in patients without anemia (P=0.629). Moreover, anemic patients had bigger total volume/lesions in the anterior cerebral artery/middle cerebral artery (ACA/MCA) and MCA regions compared to the non-anemic patients (31.89±55.78 mm3 vs. 17.08±37.39 mm3, P=0.049; and 54.54±74.72 mm3 vs. 33.75±46.03 mm3, P=0.034). Anemia was independently associated with the volume/lesion in the ACA/MCA (ß=16.796, 95% confidence interval [95% CI] 2.001 to 31.591, P=0.026) and in the MCA zone (ß=0.020, 95% CI 0.001 to 0.040, P=0.041). CONCLUSIONS: Patients with pre-procedural anemia may have bigger total volume/lesions in the ACA/MCA and MCA regions compared to the non-anemic patients. Whether the consequences of bigger total volume/lesions impact neurological and cognitive outcomes remains to be investigated.

Template-directed synthesis of ordered single-crystalline nanowires arrays of Cu2ZnSnS4 and Cu2ZnSnSe4.

Highly ordered quaternary semiconductor Cu(2)ZnSnS(4) nanowires array have been prepared via a facile solvothermal approach using anodic aluminum oxide (AAO) as a hard template. The as-prepared nanowires are uniform and single crystalline. They grow along either the crystalline [110] or [111] direction. The structure, morphology, composition, and optical absorption properties of the as-prepared Cu(2)ZnSnS(4) samples were characterized using X-ray powder diffraction, transmission electron microscopy, energy dispersive X-ray spectrometry, scanning electron microscopy, and UV-vis spectrometry. A possible formation mechanism of the nanowire arrays is proposed. Governed by similar mechanism, we show that Cu(2)ZnSnSe(4) nanowire array with similar structural characteristics can also be obtained.

Ultrasonic activation of inert poly(tetrafluoroethylene) enables piezocatalytic generation of reactive oxygen species.

Controlled generation of reactive oxygen species (ROS) is essential in biological, chemical, and environmental fields, and piezoelectric catalysis is an emerging method to generate ROS, especially in sonodynamic therapy due to its high tissue penetrability, directed orientation, and ability to trigger in situ ROS generation. However, due to the low piezoelectric coefficient, and environmental safety and chemical stability concerns of current piezoelectric ROS catalysts, novel piezoelectric materials are urgently needed. Here, we demonstrate a method to induce polarization of inert poly(tetrafluoroethylene) (PTFE) particles ( ~ 1-5 µm) into piezoelectric electrets with a mild and convenient ultrasound process. Continued ultrasonic irradiation of the PTFE electrets generates ROS including hydroxyl radicals (•OH), superoxide (•O2-) and singlet oxygen (1O2) at rates significantly faster than previously reported piezoelectric catalysts. In summary, ultrasonic activation of inert PTFE particles is a simple method to induce permanent PTFE polarization and to piezocatalytically generate aqueous ROS that is desirable in a wide-range of applications from environmental pollution control to biomedical therapy.

(Z)-5-(4-Fluoro-benzyl-idene)-1,3-thia-zolidine-2,4-dione.

In the title compound, C(10)H(6)FNO(2)S, the benzene and thia-zolidine rings make a dihedral angle of 7.52 (3)°. Intra-molecular C-H⋯O and C-H⋯S hydrogen bonds result in the formation of nearly planar five- and six-membered rings; the adjacent rings are nearly coplanar. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules.

Methyl 4-(4-fluoro-phen-yl)-6-isopropyl-2-[N-methyl-N-(methylsulfonyl)amino]-pyrimidine-5-carboxyl-ate.

In the mol-ecule of the title compound, C(17)H(20)FN(3)O(4)S, the pyrimidine and benzene rings are oriented at a dihedral angle of 35.59 (3)°. Intra-molecular C-H⋯N and C-H⋯O hydrogen bonds result in the formation of one five- and two six-membered non-planar rings. One of the six-membered rings adopts a chair conformation, while the other six-membered ring and the five-membered ring exhibit envelope conformations with O and N atoms displaced by 0.837 (3) and 0.152 (3) Å, respectively from the planes of the other ring atoms. In the crystal structure, inter-molecular C-H⋯F hydrogen bonds link the mol-ecules into infinite chains.

Methyl 4-chloro-3-nitro-benzoate.

In the title compound, C(8)H(6)ClNO(4), the mol-ecules are linked by C-H⋯O inter-actions to form a chain parallel to the a axis. The chains are further connected by slipped π-π stacking between symmetry-related benzene rings, with a centroid-to-centroid distance of 3.646 (2) Šand an inter-planar distance of 3.474 Å, resulting in an offset of 1.106 Å.

Ethyl 4-chloro-3-nitro-benzoate.

In the mol-ecule of the title compound, C(9)H(8)ClNO(4), an intra-molecular C-H⋯O hydrogen bond results in the formation of a planar five-membered ring, which is nearly coplanar with the adjacent six-membered ring, the rings being oriented at a dihedral angle of 4.40 (3)°. In the crystal structure, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules.

5-Bromo-2-methyl-pyridine N-oxide.

In the mol-ecule of the title compound, C(6)H(6)BrNO, the methyl C and oxide O atoms lie in the pyridine ring plane, while the Br atom is displaced by 0.103 (3) Å. In the crystal structure, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric dimers.

Heterostructured CIGS-Au nanoparticles: from Au-CIGS side-by-side structure to Au-core/CIGS-shell configuration.

Heterostructured Au-Copper Indium Gallium Selenide (CIGS) nanoparticles (nps) with Au-CIGS side-by-side and Au-core/CIGS-shell configurations have been synthesized in a controllable manner using seed mediated growth. Detailed microstructure analysis reveals that (112) planes in the tetragonal chalcopyrite CIGS serve as the predominant termination surfaces during single phase CIGS nanoparticle growth. Preferential nucleation of Au on such planes determines the Au-CIGS side-by-side configuration when the pre-synthesized CIGS nps are used as the seeds for further Au growth. Reversing the growth sequence by employing Au nano-seeds results in Au-core/CIGS-shell configuration, as determined by the non-preferential nucleation of CIGS on the spherical Au nanoparticle surface. The different morphological configurations of the heterostructures are found to modify the surface plasmon resonance of Au in the corresponding samples.

The electron beam irradiation damage on nanomaterials synthesized by hydrothermal and thermal evaporation methods--an example of ZnS nanostructures.

Using transmission electron microscopy-related techniques, we have compared the degradation behaviors of several different types of ZnS nanostructures, including the ZnS nanosheets synthesized by hydrothermal method (with different oxygen impurity concentration) and ZnS nanobelts grown using thermal evaporation. We have identified that displacement damage, sputtering, and oxidation mechanisms exist during the electron irradiation process. While oxidation of the nanostructure is always observed, displacement damage appears to be the dominant mechanism contributing to the final structural collapse of ZnS nanosheets (synthesized via hydrothermal methods), but sputtering mechanism becomes critical in changing the surface roughness of the ZnS nanobelts (grown by thermal evaporation). The specific damage mechanisms of these nanomaterials disclose that different synthesis process results in different structure quality (particularly impurity related interior defects) of the ZnS nanostructures, which determines their specific degradation behaviors under the electron beam irradiation.

Controlled fabrication of SnO(2) arrays of well-aligned nanotubes and nanowires.

Highly oriented SnO(2) nanotubes and nanowires arrays have been selectively fabricated via a convenient one-step wet-chemical approach using anodic aluminium oxide (AAO) as a hard template. Wall thickness of the SnO(2) nanotubes was tunable. The as-prepared nanostructures were composed of fine particles with sizes as small as 5 nm. Formation mechanism of SnO(2) nanostructure arrays with different shape is also discussed based on the experimental results. The structure, morphology, composition properties of the as-prepared samples were characterized using X-ray powder diffraction, transmission electron microscopy, energy dispersive X-ray spectrometry, scanning electron microscopy and Raman spectrum.