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The Rh(III)-catalyzed migratory insertion of bis(phenylsulfonyl)carbene into aromatic C-H bonds has been developed. A variety of bis(phenylsulfonyl)methyl derivatives were prepared with good yields under mild conditions. The methylated products were readily obtained after reductive desulfonylation. Furthermore, the diverse transformations of bis(phenylsulfonyl)methyl to trideuteriomethyl, aldehyde, and other functional groups were demonstrated.

The suppression of types I and III interferon (IFN) responses by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) contributes to the pathogenesis of coronavirus disease 2019 (COVID‐19). The strategy used by SARS‐CoV‐2 to evade antiviral immunity needs further investigation. Here, we reported that SARS‐CoV‐2 ORF9b inhibited types I and III IFN production by targeting multiple molecules of innate antiviral signaling pathways. SARS‐CoV‐2 ORF9b impaired the induction of types I and III IFNs by Sendai virus and poly (I:C). SARS‐CoV‐2 ORF9b inhibited the activation of types I and III IFNs induced by the components of cytosolic dsRNA‐sensing pathways of RIG‐I/MDA5‐MAVS signaling, including RIG‐I, MDA‐5, MAVS, TBK1, and IKKε, rather than IRF3‐5D, which is the active form of IRF3. SARS‐CoV‐2 ORF9b also suppressed the induction of types I and III IFNs by TRIF and STING, which are the adaptor protein of the endosome RNA‐sensing pathway of TLR3‐TRIF signaling and the adaptor protein of the cytosolic DNA‐sensing pathway of cGAS–STING signaling, respectively. A mechanistic analysis revealed that the SARS‐CoV‐2 ORF9b protein interacted with RIG‐I, MDA‐5, MAVS, TRIF, STING, and TBK1 and impeded the phosphorylation and nuclear translocation of IRF3. In addition, SARS‐CoV‐2 ORF9b facilitated the replication of the vesicular stomatitis virus. Therefore, the results showed that SARS‐CoV‐2 ORF9b negatively regulates antiviral immunity and thus facilitates viral replication. This study contributes to our understanding of the molecular mechanism through which SARS‐CoV‐2 impairs antiviral immunity and provides an essential clue to the pathogenesis of COVID‐19.

An enantioselective Michael addition between N-2,2,2-trifluoroethylisatin ketimines and ethylene sulfonyl fluoride has been disclosed. This method provides a facile strategy to access a range of structurally diverse isatin-derived α-(trifluoromethyl)imine derivatives with excellent yields and enantioselectivities. The intriguing combination of α-(trifluoromethyl)amine and sulfonyl fluoride groups leads to the valuable candidates for the drug discovery.

This study was to quantitatively investigate the role of morphological and functional parameters of the left atrium (LA) and left atrial appendage (LAA) with 256-slice spiral computed tomography (CT) in the recurrence of atrial fibrillation (AF) after radiofrequency ablation (RFA). Eighty-three patients with AF who underwent RFA for the first time were divided into the recurrence (n = 27) and non-recurrence (n = 56) groups. All patients underwent a 256-slice spiral CT examination before the operation. The clinical data and quantitative measurement of the morphology and functional parameters of the LA and LAA were analyzed, including the maximal and minimal volume, ejection fraction and volume, and volume strain of LAA and LA (LAAVmax, LAAVmin, LAAEF, LAAEV, and LAA-VS, LAVmax, LAVmin, LAEF, LAEV and LA-VS, respectively). The CHA2DS2-VASc score and the proportion of patients with heart failure were significantly (P 9.25 ml had the highest predictive value for AF recurrence after RFA, with the sensitivity of 85.2% and specificity of 67.9%. In conclusion, the volume of left atrium, volume and morphology of left atrial appendage have all significantly increased while the ejection fraction and volume strain of left atrium and left atrial appendage have both significantly decreased in recurrence than in non-recurrence after radiofrequency ablation. The ejection fraction and volume of left atrial appendage are significant independent predictors of atrial fibrillation recurrence after radiofrequency ablation.

Strong Rashba effects at semiconductor surfaces and interfaces have attracted great attention for basic scientific exploration and practical applications. Here, we show through first-principles investigation that applying biaxial stress can cause tunable and giant Rashba effects in ultrathin KTaO3 (KTO) (001) films with the most stable surfaces. When increasing the in-plane compressive strain to −5%, the Rashba spin splitting energy reaches ER = 140 meV, corresponding to the Rashba coupling constant αR = 1.3 eV A. We investigate its strain-dependent crystal structures, energy bands, and related properties, and thereby elucidate the mechanism for the giant Rashba effects. Further calculations show that the giant Rashba spin splitting can remain or be enhanced when capping layer and/or Si substrate are added, and a SrTiO3 capping can make the Rashba spin splitting energy reach the record 190 meV. Furthermore, it is elucidated that strong circular photogalvanic effect can be achieved for spin-polarized photocurrents in the KTO thin films or related heterostructures, which is promising for future spintronic and optoelectronic applications.

Three new LnIII-MOFs, {[Dy1.5(TAPB)1.5(DMF)]·9DMF}n (Ln = Dy (1), Er (2), Ho (3); TAPB = 4, 4′, 4″-(triazine‑2, 4, 6‑triyl‑tris‑(benzene‑4, 1-diyl)) tribenzoate), have been synthesized via a solvothermal method by using a trigonal N-containing tricarboxylate as the ligand. The coordination geometries around the central metal ions in the MOFs exhibit different deviations from ideal square antiprism (D4d symmetry) because of the coordinated solvent molecules. The ac magnetic susceptibility data is consistent with single chain magnet behavior for Dy(III) and Er(III) complexes, which have been studied by the noncritical scaling theory.

Background and Purpose— The anterior communicating artery (Acom) aneurysm is the most complex in all cerebral aneurysms, and wider vascular bifurcation angles are considered to be associated with aneurysm formation. The objective of this study was to investigate association of the Acom aneurysm formation with patient age and vascular bifurcation morphology. Methods— Three-dimensional angiographic data of 665 patients were used in this study, including 160 patients with Acom aneurysms, 66 with non-Acom aneurysms, and 439 control subjects with no aneurysms. The anterior cerebral artery bifurcation angle (Acom/A2 angle), arterial diameters, and Acom aneurysm geometric characters were examined. Results— Women of 50 to 70 years were more vulnerable to Acom aneurysm formation than men. The Acom/A2 bifurcation angle was significantly increased ( P< 0.0001) with increase of patient age. The size of the Acom aneurysm dome and neck was statistically positively correlated with the diameter of the Acom, A1 and A2 segments ( P< 0.0001). The Acom/A2 bifurcation angle was significantly ( P< 0.0001) wider in patients with than without Acom aneurysms, whereas the A1/A2 angle was significantly smaller in patients with than without Acom aneurysms ( P< 0.0001). The Acom aneurysms at the bifurcation apex mostly deviated toward the smaller angle formed between the parent A1 and branches and toward the daughter artery with a smaller diameter. The Acom aneurysms were located mostly on the dominant anterior cerebral artery. Conclusions— The presence of Acom aneurysm is significantly associated with patient age, wider angles of the anterior cerebral artery bifurcation, and smaller vascular diameter of the anterior communicating complex.

Since the discovery of a two-dimensional (2D) electron gas at the LaAlO3/SrTiO3 interface, 2D carrier gases at such oxide interfaces and surfaces have attracted great attention because they can host many important phenomena and may produce novel functional devices. Here, we show through first-principles investigations that the surface 2D electron and hole gases in a KTaO3 (KTO) thin film can be tuned by applying biaxial stress. When increasing compressive in-plane strain, the 2D carrier concentrations decrease down to zero and then a new pair of surface 2D electron and hole gases appears in which the carrier types are switched to the opposite ones. Our analysis indicates that this carrier-type switching occurs because the increasing compressive strain reverses the slope of monolayer-resolved electrostatic potential along the [001] direction. We also present strain-dependent carrier concentrations and effective masses, and explore their thickness dependence. It is further shown that the 2D carrier gases and their strain-driven carrier-type switching across the KTO layer still remain true in the presence of overlayers and epitaxial substrates. These phenomena should be useful to design novel functional devices.

Two-dimensional electron gas due to semiconductor interfaces can have high mobility and exhibits superconductivity, magnetism, and other exotic properties that are unexpected in constituent bulk materials. We study crystal structures, electronic states, and magnetism of short-period (BTO)m/(GTO)2 (m=2 and 4) superlattices consisting of insulating BaTiO3 (BTO) and GdTiO3 (GTO) by first principles calculations. Our investigation shows that the middle Ti-O monolayer in the GTO layer becomes metallic. Although both GTO and BTO share a common constituent, the Ti-O atomic layer, the M-O (M=Ba, Ti, and Gd) displacements along the c axis in each monolayer reflect the asymmetry of two interfacial Ti-O monolayers and the large distortion of the TiO6 octahedra in such superlattices, against electronic reconstruction at the interfaces and thus differentially changing the d energy levels of the three Ti-O monolayers related with the GTO layer. Such superlattices are interesting for potential spintronics applications because of their unique asymmetrical two-dimensional electron-gas properties and possible useful spin-orbit effects.

Objective The aim of this study was to construct an in vivo carotid siphon model for testing neurovascular devices for endovascular interventions. Methods A model of a human carotid siphon was pre-shaped using a glass tube from a human cadaver and used to confine a segment of one side of the common carotid artery (CCA) in canines. This segment of CCA with the glass carotid siphon on was interposed end-to-end onto the contralateral CCA so as to simulate a human carotid artery siphon in vivo. Two weeks later, the siphon model was evaluated using computed tomography angiography and digital subtraction angiography, and the covered stent specially designed for intracranial vasculature was navigated through the siphon model for a longitudinal flexibility test. Results All dogs tolerated the procedures well, and the artificial siphon model in vivo provided realistic conditions for device testing. Two weeks later, the in vivo carotid siphon model remained patent with no thrombosis. Five covered stents were navigated to pass through five siphon models successfully, with vasospasm occurring in two siphons. Conclusion Construction of an in vivo siphon model in dogs with a glass tube is feasible and useful for the test of endovascular devices for treating neurovascular diseases.

In order to investigate the role of lateral angle ratio (LA ratio) and daughter artery ratio (DA ratio) for predicting aneurysmal presence in main cerebral arterial bifurcations, three-dimensional cerebral angiographic data of major cerebral artery bifurcations were used for measurement of artery diameters and bifurcation angles including 115 middle cerebral arteries (MCAs), 59 basilar arteries (BAs), 35 internal carotid arteries (ICAs) and 115 anterior cerebral arteries (ACAs) with bifurcation aneurysms and control subjects of 1921 bifurcations with no aneurysms. The LA ratio (larger lateral angle/smaller lateral angle) and DA ratio (larger branch diameter/smaller branch diameter) were calculated, and ROC curve analysis of LA and DA ratios between normal and aneurysmal cases was performed. The LA and DA ratios of MCA bifurcations and the LA ratios of BA and ICA bifurcations with aneurysms were all significantly larger than normal bifurcations (P P P P > 0.05) between ruptured and unruptured aneurysms in MCA, BA, ICA and ACA bifurcations. In summary, normal MCA, BA and ICA bifurcations show symmetrical morphology in the lateral angles and daughter branches, whereas aneurysmal bifurcations show asymmetrical morphology. Normal ACA bifurcations have asymmetrical bilateral daughter branches while symmetrical branches are associated with ACA bifurcation aneurysm presence.

The structural, magnetic, and electronic properties of (STO)$_4$/(YTO)$_2$ superlattice consisting of Mott insulator YTiO$_3$ (YTO) and band insulator SrTiO$_3$ (STO) under strain are investigated by the density-functional-theory plus \emph{U} method. It is found that an insulator-metal transition occurs when a compressive strain of 0.2\% is applied. The structural analyses reveal that the presence of metallic state in such superlattices accompanies structural phase transition with restoring of inversion symmetry. Further study shows that this strain-induced structural transition makes the $d$ energy level of the interfacial Ti atoms of the YTO layer move upward due to the decreasing of the TiO$_{6}$ octahedral volume and induces the electron reconstruction in the whole superlattice systems. In addition, when the on-site interaction $U$ is changed from 5 to 4 eV, a similar insulator-metal transition also occurs in such superlattices due to the weakened electron correlation. These findings can improve our understanding of the insulator-metal transitions in such oxide superlattices.

An asymmetric conjugate addition of t-butyl nitroacetate to in situ generated o-quinone methides had been developed. A chiral squamide derived from 9-amino-9-deoxyepiquinine was found to be the efficient catalyst. α-Nitro-β,β-diaryl-propionates could be obtained in good yields and with excellent enantioselectivities.

The CXCL12-CXCR4 chemokine axis may play a very important role in ovarian cancer cells proliferation, migration, invasion, and peritoneal metastasis in vitro and in vivo. In this study, transfected SKOV3-CXCR4, transfected vector SKOV3-negative, nontransfected SKOV3 ovarian cancer cells, and human peritoneal mesothelial cells (HPMCs) were cultivated in vitro, and the proliferation, migration, and invasion of these ovarian cancer cells were investigated with or without the influence of the CXCL12-CXCR4 axis. Nude mice models of ovarian cancer were created by injection of ovarian cancer cells into the peritoneal cavity for investigation of ovarian cancer cells metastasis. Our results demonstrated that in the SKOV3-CXCR4 group, the cell number of proliferation, migration, or penetration through the Matrigel membrane treated with CXCL12 was significantly (p p > 0.05) differences existed in the cell number of proliferation, migration, or penetration. Coculture of HPMCs and SKOV3-CXCR4 had significantly (p p

A cascade Michael/alkylation reaction of ethyl-4-chloro-3-oxobutanoate and 2-Arylidene-1,3indandiones had been studied, providing a number of activated spirocyclopentanes in excellent yields (up to 96%) and diastereoselectivities (up to dr > 20:1). Different bases were evaluated and triethylamine was found to be the most efficient for this transformation under mild reaction.

Background and Purpose— Basilar artery (BA) bifurcation aneurysms are common, but the correlation between BA bifurcation morphology and aneurysm formation remains to be established. Our purpose was to determine the association of BA bifurcation aneurysms with patient age, sex, bifurcation angle, and branch diameter. Methods— Three-dimensional angiographic data of 195 patients were used, including 59 patients with BA bifurcation aneurysms and 136 control subjects. The angles formed between left and right posterior cerebral arteries (φ1) and between posterior cerebral artery and BA (the smaller angle defined as φ2 and the larger one as φ3), arterial diameters, and BA bifurcation aneurysm geometric characters were examined. Results— Women of 40 to 70 years of age are more vulnerable to BA bifurcation aneurysm formation than men. The φ1 bifurcation angle significantly increased ( P P P =0.09, respectively) with increase of patients’ age. Statistically significant ( P P =0.0002, respectively) positive correlations were observed between BA bifurcation branch diameter and aneurysm size. The φ1 angle was significantly ( P P Conclusions— BA bifurcation aneurysms are significantly associated with patients’ age, female sex, wider bifurcation angles, and smaller vascular diameter at the BA bifurcation.

A new synthesis of phenanthrene derivatives has been achieved through intramolecular cyclization of 1,1′-biphenyl aldehydes and ketones promoted by KOt-Bu/DMF. A free radical reaction pathway is proposed.

An efficient method for the assembly of novel and diversified benzo-fused N-heterocycles mediated by the biomass-derived N-arylated 2-aminophenol (1) has been established. Four kinds of benzo-fused N-heterocycles with six- to eight-membered ring systems, including N-arylated dibenzo[b,e][1,4]oxazepin-11(5H)-ones (4), acridones (5), 7,12-dihydrodibenzo[b,e][1,4]oxazocin-6H-ones (6) and dibenzo[b,f]azepin-10(11H)-ones (7) have been efficiently synthesized in good to excellent yields, respectively. This process is comprised of the N-arylation reaction between N-arylated 2-aminophenols (1) and 2-halogenated benzoic or phenylacetic acids to afford a series of mutli-functionalized triarylamines (3), followed by chemo- and regio-selective intramolecular lactonization or acylation under mild conditions.

This paper expounds the PTFE high molecular compound excellent physical properties and chemical properties, and resulting excellent chemical stability, corrosion resistance, weather resistance, electrical insulation, low friction and not sticky, etc. This paper introduces it has been widely used in various industrial areas, it emphatically analyzes the application and developing prospect of stable corrosion resistance in the oilfield development after coating processing of downhole drilling string.

An enantioselective conjugate addition of ethylene sulfonyl fluorides to 3-amido-2-oxindoles has been developed. Quinine-derived squaramides were identified as efficient catalysts. A series of spirocyclic oxindole sultams were prepared with excellent yields and enantioselectivities. A reaction mechanism via bifunctional activation was proposed.

A new polyhedron-based metal-organic framework (MOF), namely {[Co6(OH)2(H2O)4 (cpt)9](NO3)(DMF)13} (1, Hcpt = 4-(4′-carboxyphenyl)-1,2,4-triazole), was constructed by employment of a bifunctional triazolyl-carboxyl ligand Hcpt. Single crystal X-ray structural analysis shows that compound 1 features a rare hexanuclear {Co6(OH)2(H2O)6}10+ cluster and could be topologically viewed as a 10-connected bct net. Furthermore, compound 1 comprises octahedral cages with the inner diameter of 19.6✕12.9 A2 and 2D pore systems along the a and b axis with high density of open metal centers generated by the removal of coordinated water molecules, which contribute to a high CO2 adsorption capacity and significantly selective capture for CO2 over CH4 around room temperature. In addition, the resulting activated 1a could behave as the heterogeneous Lewis catalyst facilitates the chemical fixation of CO2 coupling with epoxides into cyclic carbonates under mind conditions.

Objective To investigate the outcomes and safety of endovascular compared with surgical clipping for multiple intracranial aneurysms. Material and methods 98 patients with 260 multiple intracranial aneurysms were treated with endovascular, surgical clipping, combined treatment, and observation. Data were retrospectively studied following treatment and at follow-up. Results In the endovascular group, 44 aneurysms were treated with coils only and 29 aneurysms were treated with stent deployment. The complete occlusion rate was 65%, and the total complication rate was 12% with no permanent deficit. After angiographic follow-up for 1–90 (mean 62) months, the total recurrence rate was 18.3%. In the clipping group, 65 aneurysms were clipped. The complete occlusion rate was 90.8%, and the complication rate was 10.9% with 1 permanent deficit. After follow-up for 11–71 (mean 49) months, the angiographic recurrence rate was 1.5%. In the combination group, 20 aneurysms were treated endovascularly. The complete occlusion rate was 78.9%, and the complication rate was 15.8% with no permanent deficit. Twenty-eight aneurysms were treated surgically with the complete occlusion rate of 89.3%, the complication rate of 20% and 3 permanent deficits. After follow-up for 1–93 (mean 58) months, the angiographic recurrence rate was 33.3% for embolization and 3.6% for clipping. Seventy-four aneurysms for observation had 2.7% regrowth rate within 1–3 years. Conclusion Endovascular embolization has an accepted complication rate but no neurological deficits compared with surgical clipping and may be a better approach for multiple intracranial aneurysms than surgical clipping.

Enzymatic catalysis of biochemical reactions is essential to all living systems. The “lock and key” and “induced fit” models were early contributions to our understanding of the mechanisms involved in the reaction between an enzyme and its substrate. However, whether a given substrate-induced conformation is rigid or remains flexible has not yet been determined. By measuring the enzyme activity and intrinsic fluorescence of a nonspecific Eisenia fetida protease-I with different chromogenic substrates, we show that in subsequent reactions of protease with substrates, both the “lock and key” and “induced fit” mechanisms are used depending on the degree of conformational change required. Chromozym-Th- or chromosym-Ch-induced protease conformations were unable to bind chromozym-U. The chromosym-U-induced protease conformation remained flexible and could be further induced by chromozym-Th and chromozym-Ch. When low concentrations of guanidine HCl were used to disturb the conformation of the enzyme, only small changes in intrinsic fluorescence of the chromozym-Th-induced protease were detected, in contrast to the native enzyme whose intrinsic fluorescence markedly increased. This indicates that the substrate-induced enzyme was relatively rigid compared with the native protease. Utilizing a lock and key mechanism for secondary substrate reactions may have adaptive value in that it facilitates high efficiency in enzymatic reactions.

Since the advent of graphene, two-dimensional (2D) materials become very attractive and there is growing interest to explore new 2D beyond graphene. Here, through density functional theory (DFT) calculations, we predict 2D wide-band-gap II-V semiconductor materials of M$_3$X$_2$ (M=Zn, Cd and X=N, P, As) with a dilated graphene-like honeycomb structure. The structure features that the group-V X atoms form two X-atomic planes symmetrically astride the centering group-IIB M atomic plane. The 2D Zn$_3$N$_2$, Zn$_3$P$_2$, and Zn$_3$As$_2$ are shown to have direct band gaps of 2.87, 3.81, and 3.55 eV, respectively, and the 2D Cd$_3$N$_2$, Cd$_3$P$_2$, and Cd$_3$As$_2$ exhibit indirect band gaps of 2.74, 3.51, and 3.29 eV, respectively. Each of the six 2D materials is shown to have effective carrier (either hole or electron) masses down to $0.03\sim 0.05$ $m_0$. The structural stability and feasibility of experimental realization of these 2D materials has been shown in terms of DFT phonon spectra and total energy comparison with related existing bulk materials. On the experimental side, there already are many similar two-coordinate structures of Zn and other transition metals in various organic materials, which can be considered to support our DFT prediction. Therefore, these 2D semiconductors can enrich the family of 2D electronic materials and may have promising potential for achieving novel transistors and optoelectronic devices., Comment: 6 pages, 5 figures

The present study reports a case of electrical storm occurring in a 43-year-old woman with dilated cardiomyopathy. The patient suffered from a cardiac electrical storm, with 98 episodes of ventricular tachycardia rapidly degenerating to ventricular fibrillation in hospital. The patient was converted with a total of 120 defibrillations. Recurrent ventricular tachycardia/fibrillation was initiated by premature ventricular beats. The patient did not respond to the use of amiodaronum. However, the administration of esmolol stabilized the patient's heart rhythm. A moderate dose of the β-blocker esmolol, administered as an 0.5-mg intravenous bolus injection followed by an infusion at a rate of 0.15 mg/kg/min, inhibited the recurrence of ventricular fibrillation and normalized the electrocardiographic pattern. The results suggest that esmolol may be able to improve the survival rate of patients with electrical storm in dilated cardiomyopathy and should be considered as a primary therapy in the management of cardiac electrical storms.

Objective To investigate quantitatively the morphology, anatomy and function of the left atrial appendage (LAA) and its relation with adjacent structures. Materials and Methods A total of 860 patients (533 men, 62.0%, age 55.9±10.4 year) who had cardiac multidetector computed tomography angiography from May to October 2012 were enrolled for analysis. Results Seven types and 6 subtypes of LAA morphology were found with Type 2 being the most prevalent. Type 5 was more significantly (P

Direct addition of tetrahydroisoquinoline derived amides to arylalkenes has been achieved in the presence of KOt-Bu/DMF. Both intermolecular and intramolecular reactions could occur in good yields. α-Amido alkyl radicals are proposed to be generated under the reaction conditions. The reaction is efficient for the synthesis of seven-membered nitrogen heterocycles. A homoprotoberberine was prepared conveniently via this method.

The coupling between ligand binding and protein conformational change is the heart of biological network. “Lock and key” theory and “induced fit” theory were early contributions to our understanding for explaining how an enzyme binds to a substrate. It was accepted that the binding of a substrate to an enzyme is often accompanied by conformational changes of the enzyme. However, whether the substrate-induced complementary conformation is flexible or rigid after a catalytic reaction remains to be determined. By testing the enzyme activity and intrinsic fluorescence of a substrate non-specific Eisenia fetida protease-I with different substrates, we show that when this enzyme reacts with a first substrate, it utilises the “induced fit” mechanism. However, in its reaction with further substrates, either the “lock and key” or “induced fit” mechanisms will be used depending on the degree of conformational change required. In contrast to the high activity of the native protease, the chromozym-Th (or -Ch)-induced protease was unable to react with chromozym-U. Chromozym-U-induced enzyme, however, had high activity with chromozym-Th and chromozym-Ch. When low concentrations of GuHCl were used to disturb the conformation of the enzyme, only small changes in intrinsic fluorescence of the CTH-induced protease were detected, in contrast to the native enzyme whose intrinsic fluorescence markedly increased. This indicates a relatively high rigidity of the substrate-induced enzyme compared with the native protease. It also indicates that the “induced fit” theory is not an adequate explanation of the mechanisms involved in such reactions. Utilising a “lock and key” mechanism for such secondary reactions may have adaptive value in that it facilitates high efficiency in enzymatic reactions.