A joint experimental and theoretical study on structural, electronic, and magnetic properties of MnGen - (n = 3-14) clusters.

A systematic structure and property investigation of MnGen - (n = 3-14) was conducted by means of density functional theory coupled with mass-selected anion photoelectron spectroscopy. This combined theoretical and experimental study allows global minimum and coexistence structures to be identified. It is found that the pentagonal bipyramid shape is the basic framework for the nascent growth process of MnGen - (n = 3-10), and from n = 10, the endohedral structures can be found. For n = 12, the anion MnGe12 - cluster probably includes two isomers: a major isomer with a puckered hexagonal prism geometry and a minor isomer with a distorted icosahedron geometry. Specifically, the puckered hexagonal prism isomer follows the Wade-Mingos rules and can be suggested as a new kind of superatom with the magnetic property. Furthermore, the results of adaptive natural density partitioning and deformation density analyses suggest a polar covalent interaction between Ge and Mn for endohedral clusters of MnGe12 -. The spin density and natural population analysis indicate that MnGen - clusters have high magnetic moments localized on Mn. The density of states diagram visually shows the significant spin polarization for endohedral structures and reveals the weak interaction between the Ge 4p orbital and the 4s, 3d orbitals of Mn.

Structural and electronic properties of exohedrally doped neutral silicon clusters LnSin (n = 5, 10; Ln = Sm, Eu, Yb).

Lanthanide-doped silicon clusters have been extensively studied in the fields of optoelectronics, magnetism and nanomaterials during the last decade. Herein, systematic structure searches for typical neutral clusters of lanthanide-doped silicon clusters LnSin (n = 5, 10; Ln = Sm, Eu, Yb) have been performed by means of density functional theory coupled with the "stochastic kicking" global search technique. It is found that the Ln atom in LnSin prefers to locate on the surface of Sin to form an exohedral structure, and this exohedral configuration may dominate the nascent structure of LnSin. The spin density and Mulliken population analyses indicate that LnSin clusters possess remarkable magnetic moments (except for YbSin), which are mainly supplied by the Ln 4f electrons (except for Yb). Density of states visually shows the significant spin polarization for open-shell structures of SmSin and EuSin. As for the YbSin (n = 5, 10) system, it has a closed-shell electronic structure with a large HOMO-LUMO gap of 2.72 eV. Bonding analysis, including localized orbital locator and electron density difference, shows that the Si-Si covalent interaction and Sm-Si electrostatic interaction are important for the structural stability of LnSin.

Microsolvation of Co- in water: Density functional theory calculations coupled with stochastic kicking method.

The hydrated clusters [Formula: see text] (n = 1-4) in gas phase are studied by density functional theory calculations (DFT) coupled with stochastic kicking method. The global minimum structure of [Formula: see text] exhibits low-symmetry pattern since only one H atom of water molecules interact with Co- ion and other ones associate with a network of hydrogen bonds. The Co- ion prefers to locate at vertex site of the water molecular clusters in such way to reduce the repulsion with O atom. These results elucidate the formation of these low-lying isomers are determined by the delicate balance between ion-water and water-water interactions.

Tripartite motif protein 11 (TRIM11), an oncogene for human lung cancer via the DUSP6-mediated ERK1/2 signaling pathway.

Evidence suggests that Tripartite Motif Containing 11 (TRIM11) has pro-tumor activity in human non-small cell lung cancer (NSCLC). However, the roles and underlying mechanisms of TRIM11 in NSCLC have not yet been fully elucidated. In this work, human lung cancer cell lines (A549, H446, and H1975) were transfected with siRNA or lentiviruses to knockdown or overexpress TRIM11 and dual-specificity phosphatase 6 (DUSP6). The cell tumor response was assessed by determining the rate of proliferation, apoptosis, the uptake of 2-[N-(7-nitrobenz-2-oxa-1, 3-diaxol-4-yl) amino]-2-deoxyglucose (2-NBDG), and the secretion of lactic acid (LD). Dominant-negative (dn)-MEK1 was used to block the ERK1/2 pathway. The mechanism was investigated by assessing the protein levels of pyruvate kinase isozymes M2 (PKM2) and DUSP6, as well as the activation of ERK1/2 pathway. Our data confirmed the anti-cancer effect of siTRIM11 in human lung cancer by demonstrating inhibition of cancer cell proliferation, induction of apoptosis, prevention of 2-NBDG uptake, suppression of LD production, and prevention of lung cancer cell (A549) tumorigenicity in nude mice. The underlying mechanism involved the up-regulation of DUSP6 and the inhibition of ERK1/2 activity. Overexpression of TRIM11 induced tumorigenesis of NSCLC in vitro, and the activation of ERK1/2 was significantly reversed by DUSP6 overexpression or additional dn-MEK1 treatment. Interestingly, we confirmed TRIM11 as a deubiquitinase that regulated DUSP6 accumulation, indicating that lung cancer progression is regulated via the DUSP6-ERK1/2 pathway. In conclusion, TRIM11 is an oncogene in NSCLC, likely through the DUSP6-mediated ERK1/2 signaling pathway.

Probing the structural, electronic, and adsorptive properties of Au16O2- clusters.

Great progress has been made in O2 adsorption on gold clusters. However, systematic investigations of O2 adsorption on [Formula: see text] clusters have not been reported. Here, we present a systematic study of the structural, electronic, and adsorptive properties of [Formula: see text] clusters by density functional theory (DFT) calculations coupled with stochastic kicking method. Global minimum searches for [Formula: see text] reveal that exohedral derivatives are more favored. Furthermore, the obtained ground-state structure exhibits significant stability, as judged by its larger adsorption energy (1.16 eV) and a larger HOMO-LUMO gap (0.57 eV). The simulated photoelectron spectra (PES) of [Formula: see text] isomers will be instructive to identify the structures in future experiments. There are three interesting discoveries in the present paper: (1) O2 undergoes chemical adsorption onto the parent [Formula: see text] clusters, but the amount of the adsorption energy is related to the parent [Formula: see text] clusters; (2) the process that O2 undergoes dissociative adsorption onto the parent [Formula: see text] clusters is exothermic; (3) [Formula: see text] isomers show smaller X-A energy gaps than those of parent [Formula: see text] clusters, reflecting that their geometric and electronic structures are distorted remarkably due to dissociative adsorption of O2.

The stability, electronic, and magnetic properties of rare-earth doped silicon-based clusters.

The rare-earth doped silicon-based clusters exhibit remarkable structural, physical, and chemical properties, which make them attractive candidates as building units in designing of cluster-based materials with special optical, electronic, and magnetic properties. The structural, stability, electronic, and magnetic properties of pure silicon Sin + 1 (n = 1-9) and rare-earth doped clusters SinEu (n = 1-9) are investigated using the "stochastic kicking" (SK) global search technique combined with density functional theory (DFT) calculations. It was found that: 1) the ground state structures of pure silicon clusters tend to form compact structures rather than cages with the increase of cluster size; 2) the ground state structures for doped species were found to be additional or substitutional sites, and the rare-earth atoms tend to locate on the surface of the silicon clusters; 3) the average binding energy of the doped clusters increased gradually and exhibited the final phenomenon of saturation with the increase of clusters size. The average binding energy of doped clusters was slightly higher than that of pure silicon clusters of the same size, which indicated that the rare-earth atom encapsulated by silicon enhanced the stability of the silicon clusters to some degree; 4) the doped clusters have strong total magnetic moments, which mainly originated from the contribution of rare-earth atoms, whereas the contribution of silicon atoms were almost negligible. As the cluster size increased, the total magnetic moments of binary mixed clusters tended to be stable.

Unexpected Cause Behind Life-threatening ECG Changes-A Diagnostic Challenge.

This case report describes a patient in their 60s who presented to the hospital with sudden loss of consciousness and foaming at the mouth.