The standard local density approximation and generalized gradient approximations fail to properly describe the dissociation of an electron pair bond, yielding large errors ~on the order of 50 kcal/mol! at long bond distances. To remedy this failure, a self-consistent Kohn–Sham ~KS! method is proposed with the exchange-correlation ~xc! energy and potential depending on both occupied and virtual ...

Melt-quenched AsxGexSe1-2x glasses over the composition range, 0 < x < 0.26, are examined in Raman scattering, T-modulated Differential Scanning Calorimetry (MDSC), and Sn Mossbauer spectroscopy measurements. The non-reversing enthalpy near Tg, ∆Hnr(x), accessed from MDSC shows a global minimum (~ 0) in the xc(1) = 0.09 < x < xc(2) = 0.16 range, and increases by an order of magnitude both at x ...

Popular approximations to the exchange-correlation (xc) energy of density functional theory do not yield spatial `step' structures in exact xc potential which are necessary describe dissociation and electron excitation with Kohn-Sham (KS) system. Via discontinuity derivative as a function number I derive analytic expressions terms KS single-particle energies for height step between variety open...

Transport system xc- found in plasma membrane of cultured mammalian cells is an exchange agency for anionic amino acids with high specificity for anionic form of cystine and glutamate. We have isolated cDNA encoding the transporter for system xc- from mouse activated macrophages by expression in Xenopus oocytes. The expression of system xc- activity in oocytes required two cDNA transcripts, and...

In vivo Positron Emission Tomography (PET) imaging of the cystine-glutamate antiporter (system xc(-)) activity with [(18)F]FSPG is meant to be an attractive tool for the diagnosis and therapy evaluation of brain diseases. However, the role of system xc(-) in cerebral ischemia and its involvement in inflammatory reaction has been scarcely explored. In this work, we report the longitudinal invest...

Cross-country (XC) skiing has been an Olympic event since the first Winter Games in Chamonix, France, in 1924. Due to more effective training and tremendous improvements in equipment and track preparation, the speed of Olympic XC-ski races has increased more than that of any other Olympic endurance sport. Moreover, pursuit, mass-start, and sprint races have been introduced. Indeed, 10 of the 12...

Cocaine produces a persistent reduction in cystine– glutamate exchange via system xc in the nucleus accumbens that may contribute to pathological glutamate signaling linked to addiction. System xc influences glutamate neurotransmission by maintaining basal, extracellular glutamate in the nucleus accumbens, which, in turn, shapes synaptic activity by stimulating group II metabotropic glutamate a...

When ecotropic murine leukemia virus was assayed by a methylcellulose-XC cell procedure, plaque titers showed less test-to-test variation, more uniform dose-response curves, and larger plaque sizes, as compared with results of the conventional liquid overlay-XC cell test system. This assay therefore seems to be reliable and useful for the titration of ecotropic murine leukemia virus.

s nad [ρ A ,ρ B ] and E xc nad [ρ A ,ρ B ] 5903 4.1.2. Spin-Density Generalization of T s nad [ρ A ,ρ B ] 5906 4.1.3. Linearization of the Functionals T s nad [ρ A ,ρ B ] and E xc nad [ρ A ,ρ B ] 5906 4.