Excess Valency as an Intrinsic Scale of Lewis Basicity

The Lewis definition of basicity has no single reference to establish a universal order of base strength. To explore valency as an gauge of Lewis basicity, quantum mechanical calculations have been performed using the meta-hybrid density functional M06-2X with Dunning style basis sets. The electronic and thermodynamic properties of 132 isolated Lewis bases and 28 boroamine adducts have been computed. Natural bond orbital (NBO) analysis was conducted to calculate the valence population and to define the excess valency, EV, as a scale of Lewis basicity. A final equation of EV=-1.07(χ ̅_sub-χ_donor )+0.74(r ̅_sub-r_donor) results in a correlation of 0.87 for all investigated bases. The use of this model alleviates the confusion of multiple base scales and underscores the periodic nature of the electronic component of basicity. Combining excess valency with the double-scale equation of Drago resulted in the use of excess valency as a means of predicting adduct bond enthalpies by -∆H=(1.25EV+.10)*E_A+C_B C_A

Blackbody-radiation-assisted molecular laser cooling

The translational motion of molecular ions can be effectively cooled sympathetically to temperatures below 100 mK in ion traps through Coulomb interactions with laser-cooled atomic ions. The distribution of internal rovibrational states, however, gets in thermal equilibrium with the typically much higher temperature of the environment within tens of seconds. We consider a concept for rotational cooling of such internally hot, but translationally cold heteronuclear diatomic molecular ions. The scheme relies on a combination of optical pumping from a few specific rotational levels into a ``dark state'' with redistribution of rotational populations mediated by blackbody radiation.Comment: 4 pages, 5 figure

Photoemission signature of momentum-dependent hybridization in CeCoIn5

Hybridization between f electrons and conduction bands (c-f hybridization) is a driving force for many unusual phenomena. To provide insight into it, systematic studies of CeCoIn 5 heavy fermion superconductor have been performed by angle-resolved photoemission spectroscopy (ARPES) in a large angular range at temperature of T = 6 K. The used photon energy of 122 eV corresponds to Ce 4d-4f resonance. Calculations carried out with the relativistic multiple scattering Korringa-Kohn-Rostoker method and one-step model of photoemission yielded realistic simulation of the ARPES spectra, indicating that Ce-In surface termination prevails. Surface states, which have been identified in the calculations, contribute significantly to the spectra. Effects of the hybridization strongly depend on wave vector. They include a dispersion of heavy electrons and bands gaining f-electron character when approaching Fermi energy. We have also observed a considerable variation of f-electron spectral weight at EF , which is normally determined by both matrix element effects and wave vector dependent c-f hybridization. Fermi surface scans covering a few Brillouin zones revealed large matrix element effects. A symmetrization of experimental Fermi surface, which reduces matrix element contribution, yielded a specific variation of 4f-electron enhanced spectral intensity at EF around Gamma barre and M barre points. Tight-binding approximation calculations for Ce-In plane provided the same universal distribution of 4f-electron density for a range of values of the parameters used in the model

Satisfaction and discontent of Polish patients with biological therapy of rheumatic diseases : results of a multi-center questionnaire study

Objectives: Biologics are medications widely applied in the management of inflammatory rheumatic diseases. The drugs were found to be effective but their application is associated with some disadvantages. Medication with biologics is relatively expensive, and in Poland, it is carried out in specialized centers. The study was designed to evaluate various aspects of satisfaction and dissatisfaction of Polish patients treated with biologics. Material and methods: An anonymous questionnaire was distributed in 23 Polish rheumatological centers involved in the treatment; 1212 returned questionnaires were used for analysis. Responses were received from 606 patients with rheumatoid arthritis, 427 with ankylosing spondylitis, 117 psoriatic arthritis, and 62 adult patients with juvenile idiopathic arthritis (in whom administration of the drugs had been introduced before they were 18 years old). The investigated group constituted about one-fifth of all rheumatic patients on biologics in Poland. Results: A beneficial or very beneficial influence of the medication on the state of physical health was found mostly in patients with rheumatoid arthritis (51.3 and 30.5%) and ankylosing spondylitis (51.0 and 36.8%). Family life was improved by the treatment especially in patients with ankylosing spondylitis (40.7 and 35.6% beneficial and very beneficial, respectively), sleep quality and sexual life mostly in those with ankylosing spondylitis (beneficial/very beneficial influence 41.5/38.4, and 38.7/23.9, respectively). There was a rather small influence of biological treatment on the financial situation of the patients. In general, satisfaction with the treatment was evaluated as positive or very positive in 88% of all investigated patients. In a significant part of the patients, transportation to the medical center was considered as a disadvantage of the treatment. About one-third of the patients considered laboratory and imaging tests to be done before initiation of the medication as a difficulty, and for about 40% waiting time for qualification for the medication was a significant disadvantage. The route of drug administration was without importance for 4/5 of the patients. Conclusions: Summing up, the results were similar in the patients suffering from various diseases although those with psoriatic arthritis felt the highest satisfaction (possibly due to the positive aesthetic effect), and those with ankylosing spondylitis had significant improvement in sexual life (probably due to younger age). Relatively low satisfaction was found in patients with juvenile idiopathic arthritis. There was a small influence of medication on financial status of the patients. Application of biologics has few disadvantages and most of them are associated with the organization of health services (waiting time for the tests, transportation to the medical centers)

Downregulation of Homologous Recombination DNA Repair Genes by HDAC Inhibition in Prostate Cancer Is Mediated through the E2F1 Transcription Factor

Histone deacetylase inhibitors (HDACis) re-express silenced tumor suppressor genes and are currently undergoing clinical trials. Although HDACis have been known to induce gene expression, an equal number of genes are downregulated upon HDAC inhibition. The mechanism behind this downregulation remains unclear. Here we provide evidence that several DNA repair genes are downregulated by HDAC inhibition and provide a mechanism involving the E2F1 transcription factor in the process.Applying Analysis of Functional Annotation (AFA) on microarray data of prostate cancer cells treated with HDACis, we found a number of genes of the DNA damage response and repair pathways are downregulated by HDACis. AFA revealed enrichment of homologous recombination (HR) DNA repair genes of the BRCA1 pathway, as well as genes regulated by the E2F1 transcription factor. Prostate cancer cells demonstrated a decreased DNA repair capacity and an increased sensitization to chemical- and radio-DNA damaging agents upon HDAC inhibition. Recruitment of key HR repair proteins to the site of DNA damage, as well as HR repair capacity was compromised upon HDACi treatment. Based on our AFA data, we hypothesized that the E2F transcription factors may play a role in the downregulation of key repair genes upon HDAC inhibition in prostate cancer cells. ChIP analysis and luciferase assays reveal that the downregulation of key repair genes is mediated through decreased recruitment of the E2F1 transcription factor and not through active repression by repressive E2Fs.Our study indicates that several genes in the DNA repair pathway are affected upon HDAC inhibition. Downregulation of the repair genes is on account of a decrease in amount and promoter recruitment of the E2F1 transcription factor. Since HDAC inhibition affects several pathways that could potentially have an impact on DNA repair, compromised DNA repair upon HDAC inhibition could also be attributed to several other pathways besides the ones investigated in this study. However, our study does provide insights into the mechanism that governs downregulation of HR DNA repair genes upon HDAC inhibition, which can lead to rationale usage of HDACis in the clinics

ON THE ASSIGNMENT OF THE EXCITED SINGLET STATES IN THE CO2CO_{2} MOLECULE

Author Institution: Department of Chemistry, Tennessee Technological UniversityHigh accuracy electronic structure calculations (contracted MRCI wavefunctions with the quality of several $10^{7}$ uncontracted configurations) for the energies of $CO_{2}$ in the low. est states in each of $^{1}\Sigma^{+}_{g}. ^{1}\Pi_{g}, ^{1}\Delta_{u}$ and $^{1}\Sigma^{-}_{u}$ symmetries, as a function of the symmetric stretching coordinate, will be reported. The positions of the electronically excited states have been determined with an expected accuracy of about 0.05 eV. The geometries and the harmonic force constants for the symmetric stretch modes at the barriers to linearity for the $^{1}\Sigma^{-}_{u},^{1}\Delta_{g}$, states have been calculated. The results show that the electronically excited states $^{1}\Sigma^{-}_{u}$ and $^{1}\Delta_{u}$, of linear $CO_{2}$ cross in the Franck-Condon region of the absorption spectrum with the $^{1}\Pi_{g}$, state. It has been found that the $^{1}\Delta_{u}$ state is separated by a barrier from the lowest dissociation asymptote and has a double minimum potential energy function. Implications for the interpretation of the absorption spectrum and the dynamics of the $CO_{2}$ photodissociation will be discussed. P.J.Knowles and P.Rosmus: University Chemical Laboratory, University of Cambridge, Cambridge, U.K. H.J.Werner: Department of Chemistry, University of Bielefeld, Bielefeld, German

The absorption wavelengths of sulfur chromophors of ultramarines calculated by time-dependent density functional theory

International audienc

ACCURATE MULTIREFERENCE-CI CALCULATIONS OF RADIATIVE TRANSITION PROBABILITIES. I. VIBRATIONAL TRANSITIONS WITHIN THE ELECTRONIC GROUND STATES OF OH,OH−,OH+,HF+OH, OH^{-}, OH^{+}, HF^{+}, and HCL+HCL^{+}

$^{1}$ F.H. Mies, J. Mol. Spectr. 53, 150 (1974)Author Institution: University Chemical Laboratory; Fachbereich Chemie der Universitaet Frankfurt, University Chemical LaboratoryElectric dipole moment functions of the electronic ground states of several diatomic molecules have been calculated using highly correlated multireference-configuration expansions. From these functions, Einstein transition probability coefficients of spontaneous emission and related quantities have been obtained. For the OH radical, the dependence of the dipole moment function on the atomic basis set and on the number and the structure of the reference configurations has been investigated extensively. Based on these tests, the present results are believed to be more accurate than previous theoretical and experimental data. Our transition probabilities differ significantly from earlier theoretical data published by $Mies,^{1}$ which have often been used in the past. The molecular ions $OH^{-}, OH^{+}, HF^{+}$, and $HCl^{+}$ are predicted to be stronger IR emitters than the corresponding neutral molecules. The rotationless rates $A^{1}_{0}$ of spontaneous emission are calculated to be 12.2, 137, 263, 618, and $217 sec^{-1}$ for $OH, OH^{-}, OH^{+}, HF^{+}$, and $HCl^{+}$, respectively