The bonding order of multiply bonded main-group elements is conventionally thought to be limited to triple bonds. Now, using high-level theoretical methods, it is shown that C2 and its isoelectronic molecules CN+, BN and CB− are quadruply bonded, featuring not only one σ - and two π-bonds, but also one weak ‘inverted’ bond.

Quadruple bonding in C 2 and analogous eight-valence electron species

https://diyhpl.us/~nmz787/pdf/DFT_flavor_of_coordination_chemistry.pdf

DFT flavor of coordination chemistry

Modulators of the hedgehog signaling pathway.

Although chorionic plate-derived mesenchymal stem cells (CP-MSCs) were shown to promote liver regeneration, the mechanisms underlying the effect remain unclear. Hedgehog (Hh) signaling orchestrates tissue reconstruction in damaged liver. MSCs release microRNAs mediating various cellular responses. Hence, we hypothesized that microRNAs from CP-MSCs regulated Hh signaling, which influenced liver regeneration. Livers were obtained from carbon tetrachloride (CCl4)-treated rats transplanted with human CP-MSCs (Tx) or saline (non-Tx). Sonic Hh, one of Hh ligands, increased in CCl4-treated liver, whereas it decreased in CP-MSC-treated liver with CCl4. The expression of Hh-target genes was significantly downregulated in the Tx. Reduced expansion of progenitors and regressed fibrosis were observed in the liver of the Tx rats. CP-MSCs suppressed the expression of Hh and profibrotic genes in co-cultured LX2 (human hepatic stellate cell) with CP-MSCs. MicroRNA-125b targeting smo was retained in exosomes of CP-MSCs. CP-MSCs with microRNA-125b inhibitor failed to attenuate the expression of Hh signaling and profibrotic genes in the activated HSCs. Therefore, these results demonstrated that microRNA-125b from CP-MSCs suppressed the activation of Hh signaling, which promoted the reduced fibrosis, suggesting that microRNA-mediated regulation of Hh signaling contributed to liver regeneration by CP-MSCs.

/pdf/microrna125b-mediated-hedgehog-signaling-influences-liver-wvcopg1yd8.pdf

MicroRNA125b-mediated Hedgehog signaling influences liver regeneration by chorionic plate-derived mesenchymal stem cells

Evaluation of mobile phase characteristics on three zwitterionic columns in hydrophilic interaction liquid chromatography mode for liquid chromatography-high resolution mass spectrometry based untargeted metabolite profiling of Leishmania parasites

Hydrophilic interaction chromatography of nucleoside triphosphates with temperature as a separation parameter

Hedgehog antagonist cyclopamine isomerizes to less potent forms when acidified

Synthesis of complex fused polycyclic heterocycles utilizing IMDAF reactions of allylamino- or allyloxy-furyl(hetero)arenes

The bonding situation of homonuclear and heteronuclear metal−metal multiple bonds in R3M−M′R3 (M, M′ = Cr, Mo, W; R = Cl, NMe2) is investigated by density functional theory (DFT) calculations, with the help of energy decomposition analysis (EDA). The M−M′ bond strength increases as M and M′ become heavier. The strongest bond is predicted for the 5d−5d tungsten complexes (NMe2)3W−W(NMe2)3 (De = 103.6 kcal/mol) and Cl3W−WCl3 (De = 99.8 kcal/mol). Although the heteronuclear molecules with polar M−M′ bonds are not known experimentally, the predicted bond dissociation energies of up to 94.1 kcal/mol for (NMe2)3Mo−W(NMe2)3 indicate that they are stable enough to be isolated in the condensed phase. The results of the EDA show that the stronger R3M−M′R3 bonds for heavier metal atoms can be ascribed to the larger electrostatic interaction caused by effective attraction between the expanding valence orbitals in one metal atom and the more positively charged nucleus in the other metal atom. The orbital interaction r...

Bonding analysis of metal-metal multiple bonds in R3M-M'R3 (M, M' = Cr, Mo, W; R = Cl, NMe2).

On the Mechanism of Cyclopropanation Reactions Catalyzed by a Rhodium(I) Catalyst Bearing a Chelating Imine-Functionalized NHC Ligand: A Computational Study

Andreas Krapp

Papers

Hydrophilic interaction chromatography of nucleoside triphosphates with temperature as a separation parameter

Hedgehog antagonist cyclopamine isomerizes to less potent forms when acidified

Synthesis of complex fused polycyclic heterocycles utilizing IMDAF reactions of allylamino- or allyloxy-furyl(hetero)arenes

Bonding analysis of metal-metal multiple bonds in R3M-M'R3 (M, M' = Cr, Mo, W; R = Cl, NMe2).

On the Mechanism of Cyclopropanation Reactions Catalyzed by a Rhodium(I) Catalyst Bearing a Chelating Imine-Functionalized NHC Ligand: A Computational Study