Regioselective ortho C-H insertion of N-nitrosoanilines with naphthoquinone carbenes.

A Rh(III)-catalyzed ortho C-H migratory insertion of N-nitrosoanilines with naphthoquinone carbenes has been developed. The products were obtained in good yields under mild reaction conditions. Diverse elaborations of the products were explored. This method is valuable for the synthesis of biarylamines and their derivatives.

Regioselective conjugate addition of isoxazol-5-ones to ethenesulfonyl fluoride.

The highly regioselective conjugate addition of isoxazol-5-ones to ethenesulfonyl fluoride (ESF) has been developed. In the presence of different bases, N2-alkylated and C4-alkylated isoxazol-5-ones with a sulfonyl fluoride group were obtained separately with good to excellent yields. Further transformations with amines and phenol gave sulfonamides and sulfonates. The intriguing combination of isoxazol-5-ones and the sulfonyl fluoride group produces valuable products for drug discovery.

Rh(III)-Catalyzed ortho C-H functionalization of aromatic amides with bis(phenylsulfonyl)diazomethane and α-diazosulfones.

A Rh(III)-catalyzed migratory insertion of bis(phenylsulfonyl) carbene and α-sulfonyl carbenes into ortho C-H bonds of aryl amides has been developed. The products were obtained with moderate to excellent yields under mild reaction conditions. A reaction mechanism was proposed based on the control experiments and previous studies. Diverse desulfonylation transformations of the products were achieved.

SARS-CoV-2 ORF9b antagonizes type I and III interferons by targeting multiple components of the RIG-I/MDA-5-MAVS, TLR3-TRIF, and cGAS-STING signaling pathways.

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.

Highly Enantioselective Addition of N-2,2,2-Trifluoroethylisatin Ketimines to Ethylene Sulfonyl Fluoride.

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.

Aromatic C-H Methylation and Other Functionalizations via the Rh(III)-Catalyzed Migratory Insertion of Bis(phenylsulfonyl)carbene and Subsequent Transformations.

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.

Synthesis of multisubstituted arylsulfones via a one-pot, three-component [3 + 3] benzannulation reaction.

A one-pot, three-component [3 + 3] benzannulation reaction of α,ß-unsaturated carbonyl compounds, bromoallylic sulfones, and sodium sulfinates had been developed. A series of multisubstituted arylsulfones were prepared with moderate to good yields. This method has the advantages of good step-economy, broad substrate scope and operational simplicity.

[Slit/Robo pathway participates in luteal cells apoptosis].

This study was aimed to examine the expression and function of Slit/Robo family members in mouse ovary. Real-time PCR was used to assess the mRNA expression levels of Slit/Robo family members, and immunohistochemistry was used to examine the location of Slit2 and Robo1 in the ovary. The mRNA and protein expression levels of Slit2 and Robo1 in early-, middle- and late-phase corpus luteum (CL) were examined by real-time PCR and immunohistochemistry, respectively. Blocking agent ROBO1/Fc chimera was used in the luteal cells in vitro to examine the function of Slit/Robo signaling pathway in mouse CL. The results showed that, among the Slit/Robo family members, the expression levels of ligand Slit2 and receptor Robo1 were the highest in mouse ovarian tissue. Moreover, both of them were specifically expressed in mouse luteal cells. Compared with proestrus ovaries, the expression levels of Slit2 and Robo1 mRNA in the ovaries during diestrus were significantly up-regulated (P < 0.01, P < 0.001). The mRNA expression levels of Slit2 and Robo1 in late-phase CL were significantly increased when compared with pregnant CL. Furthermore, blocking Slit/Robo signaling pathway with ROBO1/Fc chimera in the luteal cells in vitro significantly decreased the apoptotic rate of late luteal cells. These results suggest that Slit/Robo family members are mainly expressed in the late-phase CL of ovary and participate in luteal cells apoptosis.

Presence of Anterior Communicating Artery Aneurysm Is Associated With Age, Bifurcation Angle, and Vessel Diameter.

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.

Association of Basilar Bifurcation Aneurysms With Age, Sex, and Bifurcation Geometry.

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<0.0001), whereas both φ2 and φ3 angles significantly decreased (P<0.0001 and P=0.09, respectively) with increase of patients' age. Statistically significant (P<0.0001 and P=0.0002, respectively) positive correlations were observed between BA bifurcation branch diameter and aneurysm size. The φ1 angle was significantly (P<0.0001) wider in patients harboring BA bifurcation aneurysms than the control, whereas φ2 and φ3 angles in aneurysm group were significantly smaller than those in the control group (P<0.0001). The BA bifurcation aneurysms were mostly deviated toward the smaller φ2 angle side between φ2 and φ3 angles and deviated toward the smaller-diameter daughter posterior cerebral artery branch. CONCLUSIONS: BA bifurcation aneurysms are significantly associated with patients' age, female sex, wider bifurcation angles, and smaller vascular diameter at the BA bifurcation.

Annulation of ß-naphthols and 4-hydroxycoumarins with vinylsulfonium salts: synthesis of dihydrofuran derivatives.

A new synthetic approach to dihydrofuran derivatives via the annulation reaction of ß-naphthols and 4-hydroxycoumarins with vinylsulfonium salts has been developed. A variety of dihydrofuran derivatives were prepared in moderate to good yields under mild conditions. The products could be readily transformed to the corresponding furans via the dehydrogenation with DDQ.

Facile synthesis of substituted diaryl sulfones via a [3 + 3] benzannulation strategy.

A base-mediated [3 + 3] benzannulation strategy for the conversion of 1,3-bis(sulfonyl)propenes and ß,γ-unsaturated α-ketoesters to diaryl sulfones has been developed. This method provides facile, metal-free and efficient access to highly substituted diaryl sulfones in good to excellent yields. In addition, the sulfonyl group could be easily removed or converted to other functional groups via an organostannane intermediate.

Strain-driven carrier-type switching of surface two-dimensional electron and hole gases in a KTaO3 thin film.

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.

A practical synthesis of benzothiophenes via visible-light-promoted cyclization of disulfides and alkynes.

Visible-light-promoted intermolecular radical cyclization of disulfides and alkynes has been developed. Benzothiophenes bearing ester, ketone, aldehyde and aryl substituents were synthesized in good yields. The reaction was carried out in the absence of transition-metal catalysts and extra additives. Oxygen was used as the sole oxidant. In addition, the irradiation of sunlight could also promote the reaction efficiently.

Quantitative analysis of the right auricle with 256-slice computed tomography.

PURPOSE: To quantitatively measure the morphology parameters of the right auricle with 256-slice multidetector computed tomography angiography (MDCTA) in healthy people. MATERIALS AND METHODS: A retrospective analysis of 200 patients who had undergone coronary MDCTA with negative findings was performed. The raw imaging data were reconstructed and the right auricular volume, right atrial volume, right auricle height, base long and short axes, base perimeter and area, normal angle, and distance were quantitatively measured. RESULTS: Men had significantly (P < 0.05) greater values than women in the right auricular volume (13.3 ± 4.0 vs. 11.7 ± 3.7 mL) and height (33.0 ± 5.0 vs. 30.5 ± 5.2 mm), the base long axis (34.4 ± 4.1 vs. 33.2 ± 3.9 mm), area (787.6 ± 177.6 vs. 771.0 ± 143.2 mm2) and perimeter (119.2 ± 17.5 vs. 115.0 ± 13.0), and the normal distance (22.4 ± 6.6 vs. 20.2 ± 6.7 mm). The normal 95 % reference range for the right auricular parameters was put forward. The right auricular parameters had a good correlation with the right atrium volume, aortic diameter, the body weight, height, and body surface area but a bad correlation with the vertebral body height. Significantly (P < 0.05) greater values were found in the normal angle and distance in subjects below than over 40 years of age. No other significant (P > 0.05) difference existed in the other right auricular parameters. CONCLUSION: Quantitative measurements of the right auricle can help us get a good understanding of the right auricular morphology and its relationship with surrounding structures and are helpful for cardiac interventions of electrophysiology and radiofrequency ablation.

Quantitative evaluation of left ventricular volume and function in middle-aged healthy chinese people with 3 Tesla MRI.

PURPOSE: To quantitatively investigate left ventricular volume and function in middle-aged healthy subjects. MATERIALS AND METHODS: Ninety healthy volunteers underwent cardiac 3 Tesla MRI. The left ventricular end-diastolic volume (EDV) and end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), cardiac output (CO), myocardial mass (MM), and their normalized indices (EDVI, ESVI, SVI, CI, and MI, respectively) after corrected with the body surface area (BSA) were analyzed and compared at different ages. RESULTS: All subjects had successfully completed the 3-Tesla cardiac MR. Females had significantly smaller EDV (110.5 ± 9.2 versus 125.7 ± 8.3 mL), ESV (36.1 ± 3.5 versus 41.5 ± 3.8 mL), SV (74.3 ± 6.3 versus 84.2 ± 6.7 mL), CO (5.4 ± 0.8 versus 5.8 ± 0.9 l/min) and MM (73.0 ± 10.5 versus 94.8 ± 10.6 g) than males (P < 0.05). The EF had no significant (P = 0.47) difference between genders (67.3 ± 1.7 percent in females versus 66.9 ± 2.4 percent in males). After normalization with BSA, no significant (P > 0.05) difference was detected between the genders in EDVI (71.2 ± 4.3 versus 71.1 ± 4.2 mL/m2 , P = 0.882), ESVI (23.3 ± 1.9 versus 23.5 ± 1.9 mL/m2 , P = 0.733) and SVI (47.9 ± 2.9 versus 47.7 ± 3.7 mL/m2 , P = 0.698) except for CI and MI. Females had significantly (P < 0.05) greater CI (3.5 ± 0.4 versus 3.3 ± 0.4) but smaller MI (46.9 ± 5.3 versus 53.6 ± 7.6) than males. EDV, EDVI, ESV, ESVI, SV, and SVI significantly (P < 0.05) decreased with age increase. BSA was positively correlated with EDV, ESV, SV, MM, and CO. No significance (P > 0.05) was detected in other parameters. CONCLUSION: The left ventricular volume and function differs in women compared with men in the middle-aged population, and these parameters have a tendency of decrease with ageing. J. Magn. Reson. Imaging 2016;44:1143-1150.

Intramolecular cyclization of diarylmethanols and α,ß-unsaturated amides promoted by KOt-Bu/DMF: a metal-free approach towards 3,4-disubstituted quinolinones.

A facile synthesis of quinolinones through intramolecular addition of diarylmethanols to α,ß-unsaturated amides promoted by KOt-Bu/DMF is reported. A series of 3,4-disubstituted quinolinones were obtained in moderate to good yields. A reaction pathway via the ketyl radical is proposed.

Intramolecular addition of diarylmethanols to imines promoted by KOt-Bu/DMF: a new synthetic approach to indole derivatives.

KOt-Bu/DMF promoted intramolecular addition of diarylmethanols to imines was developed. A series of 2,3-disubstituted indoles was obtained in good yields. A reaction mechanism of radical cyclization and subsequent dehydration is proposed.

Switching a 2D Co(II) layer to a 3D Co7-cluster-based metal-organic framework: syntheses, crystal structures, and magnetic properties.

Two 2D layered coordination networks with formulas of {[Co(TPA)Cl](H2O)2.5}n (1) and {[Co(TPA)(µ2-OH)](H2O)2}n (2) (HTPA = 4-(1,2,4-triazol-4-yl)phenylacetic acid) were solvothermally synthesized and fully characterized. Interesting 1D Co(2+)-Cl or Co(2+)-µ2-OH chain structures were observed. By carefully adjusting the reaction conditions, a new 3D metal-organic framework (MOF) with a formula of {[Co7(TPA)6(µ3-OH)4(µ2-OH)2(H2O)4](TPA)2(DMF)3(H2O)3}n (3) was obtained. MOF 3 is built from Co7 clusters and fully deprotonated TPA ligands, which display a cubic pcu topology. Factors that influence the structures of the three TPA-based complexes, as well as their magnetic properties, were investigated in detail. The heptanuclear-Co(II)-cluster-based MOF 3 shows interesting magnetization dynamics at low temperature.

Rapid synthesis of isoquinolinones by intramolecular coupling of amides and ketones.

Amides and ketones were intramolecularly coupled in the presence of KOt-Bu/DMF. The reaction provided good yields of a variety of isoquinolinones. A reaction mechanism of radical addition and subsequent E2-elimination is proposed.