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A visible‐light‐induced photoredox‐catalyzed radical tandem cyclization of o‐isocyanodiaryl amines with arylthiodifluoroalkyl 2‐pyridyl sulfones or difluormethyl bromides has been realized for the first time. The reaction works with a broad range of substrates and provides a simple and efficient method for the synthesis of 11‐difluoromethyl‐substituted dibenzodiazepines from easily available starting materials in very mild conditions. [ABSTRACT FROM AUTHOR]

Symmetry-breaking plays a crucial role in determining the property and functionality of materials. Here, we demonstrate that symmetry-breaking can dramatically enhance the power conversion efficiency (PCE) of a two-dimensional (2D) van der Waals (vdW) heterostructure solar cell by taking a γ-phosphorus-carbide (PC)-based vdW heterostructure as a model. Thanks to its four-atom-layer structure of γ-PC, both alternately arranging P and C atoms to form a Janus structure and sliding C atom layer to change space group are two effective methods to break the symmetry. We find that in comparison with a symmetric configuration, the PCE of γ-PC/MoS2N4 with symmetry-breaking could be increased by 257.2% and 270% via forming a Janus structure and the change in space group, respectively. Particularly, the PCE of symmetry-broken γ-PC/MoSi2N4 can be further increased to 21.35% under an appropriate tensile strain, which could be attributed to small conduction band offset between constituent monolayers and suitable donor bandgap. Our study showcases that tuning the symmetry of multi-atom-layer 2D materials is an effective strategy to realize enhancement of the performance for 2D materials-based optoelectronic devices. [ABSTRACT FROM AUTHOR]

Spin plays a key role in physical and chemical reactions, such as oxygen evolution and hydrogen evolution reactions (OER/HER), but the spin–activity correlation has remained unclear. Based on a transition metal (TM)-doped PtN2 monolayer model with a well-defined spin center as an adsorption site, we here reveal that only an active spin state can enhance the strength of hydrogen adsorption, while an inert spin state offers very little influence. Specifically, the an unpaired electron along the out-of-plane direction such as in the d z 2 orbital, acting as an active spin state, will strongly hybridize with hydrogen, resulting in enhanced hydrogen binding energy because the d z 2 orbital is just enough to accommodate two electrons to form a bonding orbital. While the in-plane unpaired electron such as in the d x 2 − y 2 orbital plays a negligible role in an adsorbing hydrogen atom. This is verified by a series of single atom catalysts comprising of PtN2 monolayer by replacing a Pt atom with a TM (Fe, Co, Ni, Ru, Rh, Pd, Os, or Ir) atom or subsequent adsorbing a Cl atom. One of the most promising materials is Pd@PtN2-Cl that offers superior HER activity, even better than pure Pt. This work uncovers the nature of spin–activity correlation, thus paving the way for the design of high-performance catalysts through spin-engineering. [ABSTRACT FROM AUTHOR]

The Schottky–Mott (S–M) limit based on the S–M rule is often used to evaluate the Schottky barrier height (SBH) at metal–semiconductor (MS) van der Waals (vdW) contacts but fails at the polar interfaces. In order to extend the S–M rule to the polar interfaces, we here modify the S–M equation to predict the SBH at vdW interfaces of 2D Janus materials, taking into account the effects of intrinsic and interface dipoles. The modified S–M equation is verified based on the first-principles calculations of the MoSi2As2P2/HTaSe2F vdW interfaces, showing a sharp dependence of SBH on the dipole amplitude and direction. Specifically, n-type Schottky barriers tend to form when a semiconductor contacts with a low-work-function surface of Janus metal or a metal interfaces to the high-electron-affinity surface of Janus semiconductor; otherwise, a p-type one is preferable. Interestingly, the smallest n(p)-type SBH could be attained when both intrinsic dipole directions are the same. This work demonstrates that the S–M rule can be extended to the polar interfaces and dipole engineering is an effective strategy to tune the SBH at the MS interface. [ABSTRACT FROM AUTHOR]

Aims: Patients with persistent or de novo left ventricular (LV) dilation and/or reduced ejection fraction (EF) after correction for primary aortic (AR) or mitral (MR) regurgitation (i.e. residual LV remodelling) have not been well studied with regard to guideline‐directed medical therapy after successful aetiology‐reversing surgery. We aim to (i) compare the effectiveness of sacubitril/valsartan vs. valsartan in promoting LV reverse remodelling and (ii) explore the safety of medication withdrawal after LV recovery. Methods and results: The ReReRe study is a multicentre, randomized, open‐label, parallel trial that consists of two consecutive parts. A total of 371 patients with an LV end‐diastolic diameter (LVEDD) > 60 mm or LVEF < 50%, assessed by transthoracic echocardiography (TTE) 7–14 days after valve surgery for significant AR or primary MR will be enrolled. The 1st randomization into the sacubitril/valsartan or valsartan groups and structured follow‐up (1, 3, 6, 9, and 12 months after randomization) will be conducted to observe the primary objective as the rate of complete recovery of LV remodelling (i.e. LVEDD < 55 mm and LVEF ≥ 60% by TTE at two consecutive visits). Those who have complete recovery of LV remodelling will be enrolled in Study Part 2; consequently, they will receive the 2nd randomization into the medication withdrawal or maintenance group and 6‐monthly visits for the observation of the primary objective as the rate of LV remodelling relapse (LVEDD > 60 mm or LVEF < 50%). The secondary objectives include the rate of composite clinical outcomes and the degree of change in 6‐min walk distance and Kansas City Cardiomyopathy Questionnaire scores. Conclusions: The ReReRe study will provide new evidence for the treatment of patients with residual LV remodelling after curable unloaded surgery, as well as the duration of treatment. The study results will fill the gap in identifying an appropriate medical therapy regimen for this group of patients and perhaps for those with reversible aetiologies of heart failure. [ABSTRACT FROM AUTHOR]

In this paper, a triple shape memory material was prepared by ultra‐simple melt blending from poly(ε‐caprolactone) (PCL), poly(propylene carbonate) (PPC) and ethylene‐α‐octene block copolymer (OBC). The obtained material possessed a co‐continuous phase morphology and presented an excellent triple shape memory effect (triple‐SME). Theoretical prediction demonstrated that a special continuous phase morphology could be constructed by adjusting the proportions of the blend. Moreover, the results indicated that a close relationship existed between the phase morphology and the triple‐SME of PCL/PPC/OBC. The sample with 35 vol% PPC content contributed to the formation of a continuous phase morphology and exhibited the optimal triple‐SME. Additionally, the sample PCL/PPC/OBC (32.5/35/32.5) showed outstanding structure and performance stability during cycle loading–unloading tests, which evidenced the prominent cycling shape memory property (nearly 100% shape fixing and recovery of temporary shape). Overall, this work could provide an efficient, convenient and recyclable method to obtain high‐performance shape memory materials. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

poly(ε‐caprolactone) (PCL)/ethylene‐α‐octene block copolymer (OBC)/multiwalled carbon nanotubes (MWCNTs) nanocomposite was prepared in this work. After achieving the co‐continuous phase morphology of PCL/OBC binary blend by varying the composition, MWCNTs were selectively dispersed in OBC as conductive filler to investigate the electrically responsive shape memory effect. The results indicated that the shape memory effect (SME) of PCL/OBC was sensitive to the composition of component. The optimal SME could be observed when the volume fraction of PCL and OBC was 50:50, which was applied for the further exploration of electrically responsive SME. Additionally, the MWCNTs selectively located in OBC formed percolated structure when the component of MWCNTs was 1.5 vol%, and the shape recovery ratio (Rr) increased with MWCNTs content and applied voltage. Typically, the sample exhibited the excellent electrically actuated shape memory effect when the MWCNTs loading was 5 vol%. Ultimately, it only took 30 s for the sample to achieve the 100% recoverability under 30 V. POLYM. COMPOS., 40:E1353–E1363, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Characteristic cardiac phenotypes are detected by cardiovascular magnetic resonance in patients with different clinical phenotypes and genotypes of mitochondrial myopathy. A normal left ventricle (LV) chamber size with a reduced ejection fraction of 34% and an enlarged right ventricle (RV) with decreased systole were identified by echocardiography. Further investigation by cardiac magnetic resonance (CMR) detected RV dilation, biventricular hypokinesis, and trace pericardial effusion. [Extracted from the article]