On the calculation of the bandgap of periodic solids with MGGA functionals using the total energy

During the last few years, it has become more and more clear that functionals of the meta generalized gradient approximation (MGGA) are more accurate than GGA functionals for the geometry and energetics of electronic systems. However, MGGA functionals are also potentially more interesting for the electronic structure, in particular, when the potential is nonmultiplicative (i.e., when MGGAs are implemented in the generalized Kohn-Sham framework), which may help to get more accurate bandgaps. Here, we show that the calculation of bandgap of solids with MGGA functionals can also be done very accurately in a non-self-consistent manner. This scheme uses only the total energy and can, therefore, be very useful when the self-consistent implementation of a particular MGGA functional is not available. Since self-consistent MGGA calculations may be difficult to converge, the non-self-consistent scheme may also help to speed up the calculations. Furthermore, it can be applied to any other types of functionals, for which the implementation of the corresponding potential is not trivial

Clostridioides difficile virulence genes expression in an insert plate model

Clostridioides difficile is a Gram positive bacterium sporulant and requires strict anaerobiosis. The intestinal carriage of C. difficile can be asymptomatic, but in cases of infection it is associated with different clinical signs of disease that can vary from mild diarrhea to pseudomembranous colitis or even death. Expression of C. difficile virulence gene was studied in an in vitro insert plate model. The objective of this study was to identify the timing of expression of virulence gene of C. difficile. In compartment “in”, a nutritive matrix, salt biles and a quantity of C. difficile spores were placed. In compartment “out”, a nutritive matrix and salt biles were placed. Several plates were made to study a plate without feces, two with a variation of the concentration of spores, two with a variation of the concentration of feces concentration and four with a variation of the microflora. Total DNA and RNA were extracted and RT-qPCR targeting mldA (evolved in cell division), gluD (housekeeping genes), tcdB and tcdA (toxins genes) This method of culture allows the growth of C. difficile under different growth conditions. The plate without feces is the benchmark. The expression of genes varies depending on the growth conditions and some donors (D2 and D4) will promote the production of toxins. Among the donors, donors 4 gives us a pattern that is closer to the expression of the virulence genes of the insert without feces. The next step of our study will use metatranscriptomics to identify the expression of certain genes that have an impact on colonization

Initial study of methylclonazepam in generalized anxiety disorder - Evidence for greater power in the cross-over design

The anxiolytic activity of methylclonazepam was compared to lorazepam and placebo in a double-blind, randomized cross-over study, using a latin square design, in 18 inpatients meeting Research Diagnostic Criteria for Generalized Anxiety Disorders. Patients presented at least 1 year of symptomatology and had a minimum score of 20 on the Hamilton Anxiety Scale, despite chronic anxiolytic pharmacotherapy. Daily dosage was flexible, from three to six tablets of methylclonazepam 1 mg, lorazepam 2.5 mg, or placebo. Clinical evaluation included Hamilton Anxiety Scale, Clinical Global Impression (CGI), a side-effects checklist, completed every 2 days, and the global preference of the patient for one of the treatment periods. Results showed a highly significant superiority of both benzodiazepines over placebo on the Hamilton Scale (P<0.000001) and CGI (P<0.001), and also a significant superiority of methylclonazepam over lorazepam on the Hamilton Scale (P<0.01), CGI-1 (P<0.01), and in the number of patient preferences (14 versus 1; P<0.001), with no significant differences in side-effects or related to position in the trial. These results support the value of the cross-over design in chronic and severe anxious inpatients for the demonstration of differences in efficacy between anxiolytic pharmacotherapies. © 1985 Springer-Verlag

Positive-P and Wigner representations for quantum-optical systems with nonorthogonal modes

We generalize the basic concepts of the positive-P and Wigner representations to unstable quantum-optical systems that are based on nonorthogonal quasimodes. This lays the foundation for a quantum description of such systems, such as, for example an unstable cavity laser. We compare both representations by calculating the tunneling times for an unstable resonator optical parametric oscillator

Excess-noise-enhanced parametric down conversion

We calculate the influence of excess noise on parametric down conversion in an unstable optical parametric oscillator (OPO), using a quantum quasimode description. We find a strongly enhanced pair photon generation rate below threshold as compared to a conventional stable cavity setup of comparable gain and loss. In addition, the oscillation threshold is lowered due to the influence of the excess noise and the squeezing properties of the emitted light are significantly changed. In general, the maximal quantum-noise suppression in one quadrature component is reduced, which poses strong limitations for the practical usefulness of a geometrically unstable OPO source. The analytical results from our quasimode description are in good agreement with numerical simulations using a positive-P representation of the field in mode space and in position space