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Molecular modification induced through the resonant attachment of a low energy electron (LEE) is a novel approach for molecular engineering. In this communication, we explore the possibility to use the LEE as a quantum tool for the in situ preparation of short lived molecules. Using ab initio quantum chemical methods, this possibility is best illustrated for the in situ preparation of the intrinsically short-lived carbon-carbon covalent dimer of CO from a glyoxal molecule. The chemical conversion of glyoxal to the covalent dimer of CO is initiated and driven by the resonant capture of a near 11 eV electron by the glyoxal molecule. The resulting two-particle one-hole (2p-1h) negative ion resonant state (NIRS) of the glyoxal molecule undergoes a barrierless radical dehydrogenation reaction and produces the covalent dimer of CO. The autoionization electron spectra from the 2p-1h NIRS at the dissociation limit of the dehydrogenation reaction provides access to the electronic states of the CO dimer. The overall process is an example of a catalytic electron reaction channel [ABSTRACT FROM AUTHOR]

The resonance capture of ubiquitous very low energy electrons (vLEEs) into the π* orbitals of nucleobases is a potential doorway to DNA damage. Our ab initio quantum chemical calculations reveal a possible protection function, which is specific to the complementary basepairing, against such vLEE induced DNA damage. [ABSTRACT FROM AUTHOR]

Hepato-renal pathology associated with nutritional and metabolic diseases in chickens was studied using samples brought for autopsy to the Centre of Excellence in Pathology. Among these; fatty liver syndrome was observed in 41 chickens. The liver showed moderate to severe enlargement with yellowish to yellowish brown discoloration and hepatocytes were distended with fat vacuoles. Gout was observed in 18 chickens showing deposition of white chalky crystals on the visceral organs and joints. Microscopically the liver and kidneys showed urate deposition. Ascites syndrome was observed in 13 chickens with accumulation of clear yellowish fluid in the abdominal cavity. Histology of liver revealed multifocal random areas of necrosis and disorganization of hepatic cords. Kidney showed intertubular hemorrhages and degeneration. [ABSTRACT FROM AUTHOR]

Abstract: We report a theoretical study of intra-molecular electronic coupling in a symmetric DBA (donor–bridge–acceptor) complex, in which a donor electronic site is coupled to an acceptor site by way of intervening orbitals of a molecular bridge unit. In the off-resonant (deep tunneling) regime of electronic transport, the lowest unoccupied molecular orbitals (MO’s) of the DBA system are split into distinguishable donor/acceptor and bridge orbitals. The effect of geometrical changes at the bridge on the donor/acceptor electronic energy manifold is studied for local stretching and bending modes. It is demonstrated that the energy splitting in the manifold of donor/acceptor unoccupied MOs changes in response to such changes, as assumed in simple McConnell-type models. Limitations of the simple models are revealed where the electronic charging of the bridge orbitals correlates with increasing donor/acceptor orbital energy splitting only for stretching but not for bending bridge modes. [Copyright &y& Elsevier]

Abstract: Electron transfer and electronic energy transfer (EET) processes are ways by which different molecules can interact, signalling their state, by EET from a donor (D) to an acceptor (A). This D–A transfer is often observed in an intermolecular process but it can also occur intramolecularly, that is between two bridged parts of a bichromophoric molecule. In this paper we present results pertaining to electronic energy transfer in a newly synthesized rhodamine–azulene (Rh–Az) a bichromophoric molecule, in which a full adder can be implemented. The intramolecular EET rate constant in the Rh–Az molecule was found to be 7.81×109 s−1. [Copyright &y& Elsevier]

Abstract: The experimental strategies and theoretical understanding in transforming molecular conformations with good SHG response functions into polymers with the help of chiral groups are discussed. Chirality plays an important role in designing new types of stable second-order NLO materials. The presence of chiral molecules in the main chain of the polymer introduces acentric conformations and thereby increases the SHG efficiency. On the other hand, for strong donor and acceptor groups between a pi-bridge, large SHG coefficients can be realized at the molecular scale. Chiral molecules are noncentrosymmetric with a nonvanishing electric-dipole-allowed second-order response, which persists in bulk samples also. On the other hand, contributions of magnetic-dipole interactions, which can be strong in chiral materials, allow second-order processes in centrosymmetric materials. Also the polymers incorporated with chiral molecules showed higher response than the standard MNA. This could be due to the chiral component contribution to the electric and magnetic-dipole tensor. [Copyright &y& Elsevier]

Static polarizability and first- and second-order hyperpolarizability tensors are computed at the correlated level for a series of para-nitroaniline derivatives. The importance of including electron correlation effects in the determination of equilibrium structure and the molecular properties is investigated. A qualitative description of the substitution effects, planarity, and symmetric effect of the molecule on the molecular susceptibility is discussed. [ABSTRACT FROM AUTHOR]

The article reports on the research of hepatocellular carcinoma and cholangiocellular carcinoma in a duck.

Dissociative electron attachment (DEA) to acetone is studied in terms of the absolute cross section for various fragment channels in the electron energy range of 0-20 eV. H- is found to be the most dominant fragment followed by O- and OH- with only one resonance peak between 8 and 9 eV. The DEA dynamics is studied by measuring the angular distribution and kinetic energy distribution of fragment anions using Velocity Slice Imaging technique. The kinetic energy and angular distribution of H- and O- fragments suggest a many body break-up for the lone resonance observed. The ab initio calculations show that electron is captured in the multi-centered anti-bonding molecular orbital which would lead to a many body break-up of the resonance. [ABSTRACT FROM AUTHOR]