Metalloradical complex Co-C˙Ph3 catalyzes the CO reduction in gas phase: a theoretical study.

Metal-stabilized radicals have been increasingly exploited in modern organic synthesis. Here, we theoretically designed a metalloradical complex Co-C˙Ph3 with the triplet characters through the transition metal cobalt (Co0) coordinating a triphenylmethyl radical. The potential catalytic role of this novel metalloradical in the CO2 reduction with H2/CH4 in the gas phase was explored via density functional theory (DFT) calculations.

Resveratrol, a natural polyphenol, prevents chemotherapy-induced cognitive impairment: Involvement of cytokine modulation and neuroprotection.

Chemotherapy-induced cognitive impairment, also known as "chemobrain," is a common side effect. The purpose of this study was to examine whether resveratrol, a natural polyphenol that has nootropic effects, could prevent chemobrain and its underlying mechanisms. Mice received three injections of docetaxel, adriamycin, and cyclophosphamide (DAC) in combination, a common chemotherapy regimen, at two-day intervals within one week.

Design of a catalyst through Fe doping of the boron cage BH for CO hydrogenation and investigation of the catalytic character of iron hydride (Fe-H).

The innovative catalyst Fe@BH is designed through Fe doping of the boron cage BH and is employed to catalyze CO hydrogenation using a quantum mechanical method. First, the structure of the Fe@BH complex is characterized through calculated B NMR chemical shifts and Raman spectra, and the interactions between Fe and the four H atoms of the opening in the cage are analyzed, which show that various iron hydride (Fe-H) characteristics exist. Subsequently, the potential of Fe@BH as a catalyst for the hydrogenative reduction of CO in the gas phase is computationally evaluated.

CTT1 overexpression increases the replicative lifespan of MMS-sensitive Saccharomyces cerevisiae deficient in KSP1.

Ksplp is a nuclear-localized Ser/Thr kinase that is not essential for the vegetative growth of yeast. A global gene function analysis in yeast suggested that Ksplp was involved in the oxidative stress response; however, the underlying mechanism remains unclear. Here, we showed that KSP1-deficient yeast cells exhibit hypersensitivity to the DNA alkylating agent methyl methanesulphonate (MMS), and treatment of the KSP1-deficient strain with MMS could trigger abnormal mitochondrial membrane potential and up-regulate reactive oxygen species (ROS) production.

Identification of lesion images from gastrointestinal endoscope based on feature extraction of combinational methods with and without learning process.

The gastrointestinal endoscopy in this study refers to conventional gastroscopy and wireless capsule endoscopy (WCE). Both of these techniques produce a large number of images in each diagnosis. The lesion detection done by hand from the images above is time consuming and inaccurate.

All-metal electride molecules CuAg@Ca7M (M = Be, Mg, and Ca) with multi-excess electrons and all-metal polyanions: molecular structures and bonding modes as well as large infrared nonlinear optical responses.

All-metal electride molecules, CuAg@Ca7M (M = Be, Mg and Ca), have been designed and researched in theory for the first time. In these molecules, a pull-push electron relay occurs. Unusually, the all-metal polyanions of fourfold negatively charged [Cu-Ag-Be/Mg](4-) and [Cu-Ag](4-) with 4 extra electrons gained from Ca atoms push the remaining valence electrons of the Ca atoms forming the multi-excess electrons (Ne = 10/12).

Electric field effects on the intermolecular interactions in water whiskers: insight from structures, energetics, and properties.

Modulation of intermolecular interactions in response to external electric fields could be fundamental to the formation of unusual forms of water, such as water whiskers. However, a detailed understanding of the nature of intermolecular interactions in such systems is lacking. In this paper, we present novel theoretical results based on electron correlation calculations regarding the nature of H-bonds in water whiskers, which is revealed by studying their evolution under external electric fields with various field strengths.

CIA2 deficiency results in impaired oxidative stress response and enhanced intracellular basal UPR activity in Saccharomyces cerevisiae.

Yeast Cia2p is a component of the cytosolic Fe/S protein assembly (CIA) machinery. Initial studies of the CIA machinery were performed in yeast, but the precise role of Cia2p in this eukaryote is still unknown. We report that CIA2 deficiency results in impaired oxidative stress response, as evidenced by increased sensitivity to the oxidant cumene hydroperoxide (CHP), impaired activities of superoxide dismutases and aconitase and decreased replicative lifespan in the mutants.

A new strategy for simultaneously enhancing nonlinear optical response and electron stability in novel cup-saucer⁺-cage⁻-shaped sandwich electride molecules with an excess electron protected inside the cage.

Novel cup-saucer-cage-shaped sandwich electride molecules calix[4]pyrrole···K3O(+)···e@C(n)F(n)(-), (n = 8, 10, 14, 20, and 36) with an excess electron protected inside the C(n)F(n) cage are constructed theoretically. In the sandwich structures, the below calix[4]pyrrole cup pushes the valence electron of the sandwiched superalkali atom K3O saucer, forming an excess electron, which is further pulled and protected inside the above C(n)F(n) cage, thus an electron-transfer relay occurs. In particular, owing to the unusual electron transfer, an unusual and fortunate phenomenon is discovered that increasing the C(n)F(n) cage size enhances not only the nonlinear optical response (β0), but also the electron stability (VIP).

LRRK2 R1441G mice are more liable to dopamine depletion and locomotor inactivity.

Objective: Mutations in leucine-rich repeat kinase 2 (LRRK2) pose a significant genetic risk in familial and sporadic Parkinson's disease (PD). R1441 mutation (R1441G/C) in its GTPase domain is found in familial PD. How LRRK2 interacts with synaptic proteins, and its role in dopamine (DA) homeostasis and synaptic vesicle recycling remain unclear.

The effects of external electric field: creating non-zero first hyperpolarizability for centrosymmetric benzene and strongly enhancing first hyperpolarizability for non-centrosymmetric edge-modified graphene ribbon H2N-(3,3)ZGNR-NO2.

How to generate a non-zero first hyperpolarizability for a centrosymmetric molecule is a challenging question. In this paper, an external (pump) electric field is used to make a centrosymmetric benzene molecule generate a non-zero value of the electric field induced first hyperpolarizability (β (F) ). This comes from the centrosymmetry breaking of electron cloud.

New acceptor-bridge-donor strategy for enhancing NLO response with long-range excess electron transfer from the NH2...M/M3O donor (M = Li, Na, K) to inside the electron hole cage C20F19 acceptor through the unusual σ chain bridge (CH2)4.

Using the strong electron hole cage C20F19 acceptor, the NH2...

Li2 trapped inside tubiform [n] boron nitride clusters (n=4-8): structures and first hyperpolarizability.

The geometries and electronic properties of tubiform [n] boron nitride clusters entrapping Li(2) (Li(2)@BN-cluster(n,0); n=4-8), obtained by doping BN-cluster(n,0) with Li(2) molecules, are investigated by means of DFT. The effects of tube diameter n on the dipole moment μ(0), static polarizability α(0), and first hyperpolarizability β(0) are elucidated. Both the dipole moment and polarizability increase with increasing tube diameter, whereas variation of the static first hyperpolarizability with tube diameter is not monotonic; β(0) follows the order 1612 (n=4)<3112 (n=5)<5534 (n=7)<8244 (n=6)<12,282 a.

Intercage electron transfer driven by electric field in Robin-Day-type molecules.

A new class of isomers, namely, intercage electron-transfer isomers, is reported for fluorinated double-cage molecular anion e(-)@C(20)F(18)(NH)(2)C(20)F(18) with C(20)F(18) cages: 1 with the excess electron inside the left cage, 2 with the excess electron inside both cages, and 3 with the excess electron inside the right cage. Interestingly, the C(20)F(18) cages may be considered as two redox sites existing in a rare nonmetal mixed-valent (0 and -1) molecular anion. The three isomers with two redox sites may be the founding members of a new class of mixed-valent compounds, namely, nonmetal Robin-Day Class II with localized redox centers for 1 and 3, and Class III with delocalized redox centers for 2.

The association of a single nucleotide polymorphism in the promoter region of the LAMA1 gene with susceptibility to Chinese high myopia.

Purpose: High myopia is a severe hereditary ocular disease leading to blindness. LAMA1 (alpha subunit of laminin) is a promising candidate gene for high myopia present in the MYP2 (myopia 2) region. The purpose of this study was to determine if high myopia is associated with single nucleotide polymorphism (SNP) variants in LAMA1 in Chinese subjects.

Exceptionally large second-order nonlinear optical response in donor-graphene nanoribbon-acceptor systems.

Graphene nanoribbon (GNR) has been used, for the first time, as an excellent conjugated bridge in a donor-conjugated bridge-acceptor (D-B-A) framework to design high-performance second-order nonlinear optical materials. Owing to the unique diradical planar conjugated bridge of GNR, D(NH(2))-GNR-A(NO(2)) exhibits exceptionally large static first hyperpolarizability (β(0)) up to 2.5×10(6) a.

Electric field-driven acid-base chemistry: proton transfer from acid (HCl) to base (NH3/H2O).

It is well-known that single H3N-HCl and H2O-HCl acid-base pairs do not react to form the ion pairs, H4N(+)Cl(-) and H3O(+)Cl(-), in isolation. On the basis of ab initio method, we propose a physical method of external electric field (Eext) to drive the proton transfer from acid (HCl) to base (NH3/H2O). Our results show that when Eext along the proton-transfer direction achieves or exceeds the critical electric field (Ec), the proton transfer occurs, such as, the Ec values of proton transfer for H3N-HCl and H2O-HCl are 54 × 10(-4) and 210 × 10(-4) au, respectively.

Reaction mechanism of CH + C(3)H(6): a theoretical study.

A detailed theoretical study is performed at the B3LYP/6-311G(d,p) and G3B3 (single-point) levels as an attempt to explore the reaction mechanism of CH with C(3)H(6). It is shown that the barrierless association of CH with C(3)H(6) forms two energy-rich isomers CH(3)-cCHCHCH(2) (1), and CH(2)CH(2)CHCH(2) (4). Isomers 1 and 4 are predicted to undergo subsequent isomerization and dissociation steps leading to ten dissociation products P(1) (CH(3)-cCHCHCH + H), P(2) (CH(3)-cCCHCH(2) + H), P(3) (cCHCHCH(2) + CH(3)), P(4) (CH(3)CHCCH(2) + H), P(5) (cis-CH(2)CHCHCH(2) + H), P(6) (trans-CH(2)CHCHCH(2) + H), P(7) (C(2)H(4) + C(2)H(3)), P(8) (CH(3)CCH + CH(3)), P(9) (CH(3)CCCH(3) + H) and P(12) (CH(2)CCH(2) + CH(3)), which are thermodynamically and kinetically possible.

Push-pull electron effects of the complexant in a Li atom doped molecule with electride character: a new strategy to enhance the first hyperpolarizability.

Differing from the reported strategy of push or pull electron effects of the complexant, a new strategy of the combination effects of both push and pull electrons of the complexant to enhance the first hyperpolarizability is performed with two Li atom doped complexants with a pair of difluorophenyl subunit rings. Large variance of the static first hyperpolarizabilities (beta(0)) are exhibited at the MP2/6-311++G(d,p) level. The order of the beta(0) values is 2.

[Research progress in A-type lamins].

A-type lamins are encoded by LMNA and a major component of the nuclear lamina, a dynamic meshwork located just under the nuclear envelope, providing essential mechanical support. In addition, A-type lamins associate with chromatin both directly and indirectly and have been suggested to play important roles in chromatin organization, transcription, DNA replication, and apoptosis. Mutations of LMNA or its encoding proteins can cause a series of human hereditary diseases which are collectively referred to as laminopathies.

Double-stranded break can be repaired by single-stranded oligonucleotides via the ATM/ATR pathway in mammalian cells.

Single-stranded oligonucleotide (SSO)-mediated gene modification is a newly developed tool for site-specific gene repair in mammalian cells; however, the corrected cells always show G2/M arrest and cannot divide to form colonies. This phenomenon and the unclear mechanism seriously challenge the future application of this technique. In this study, we developed an efficient SSO-mediated DNA repair system based on double-stranded break (DSB) induction.

Single-stranded oligonucleotide-mediated gene repair in mammalian cells has a mechanism distinct from homologous recombination repair.

Single-stranded DNA oligonucleotide (SSO)-mediated gene repair has great potentials for gene therapy and functional genomic studies. However, its underlying mechanism remains unclear. Previous studies from other groups have suggested that DNA damage response via the ATM/ATR pathway may be involved in this process.