Search results for "Function"

An ab initio potential energy surface for the C2H2-N2 system

2012

International audience; An ab initio potential energy surface determined at the CCSD(T) level of theory is presented for the van der Waals complex C2H2-N2. Additional calculations performed with the HF- and DFT-SAPT methods compare well with the CCSD(T) results and allow a better understanding of the main features of this interaction potential surface. An expansion of this surface over spherical harmonics has also been performed. The global energy minimum of the complex is obtained for the linear conformation. The T conformations are the least attractive. Such characteristics mainly arise because of the variation, in sign and in absolute value of the electrostatic energy between all these c…

Hybrid Quantum Mechanics/Molecular Mechanics Simulations with Two-Dimensional Interpolated Corrections:  Application to Enzymatic Processes

2006

Hybrid quantum mechanics/molecular mechanics (QM/MM) techniques are widely used to study chemical reactions in large systems. Because of the computational cost associated with the high dimensionality of these systems, the quantum description is usually restricted to low-level methods, such as semiempirical Hamiltonians. In some cases, the description obtained at this computational level is quite poor and corrections must be considered. We here propose a simple but efficient way to include higher-level corrections to be used in potential energy surface explorations and in the calculation of potentials of mean force. We evaluate a correction energy term as the difference between a high-level …

PREPARATION AND CHARACTERIZATION OF BIOPOLYMERIC POROUS STRUCTURES FOR ADVANCED APPLICATIONS

Porous biopolymers received an increasing academic and industrial interest finding application in several fields such as tissue engineering, bioprocess intensification and waste removal. Tissue engineering combines the knowledge of materials science and bioengineering in order to develop structures able to substitute and restore the normal function of injured or diseased tissues. In this context, polymeric 3D or 2D scaffolds are widely investigated as temporary cell guidance during the tissue restore. Porous biomaterials can offer a versatile and cost effective way for immobilization of filamentous microorganisms in submerged fermentation processes for the production of biologically active …

Psychological Approaches to Origins and Treatments of Somatoform Disorders

2010

Medically unexplained symptoms are the defining feature of somatoform disorders (SFD) as currently included in Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and the International Classification of Diseases, Tenth Edition. Cognitive, behavioral, biological, and social variables are important to our understanding of SFD. Research in the past decade has highlighted the central role of (a) prolonged attention allocation to bodily sensations, (b) the dysfunctional role of catastrophizing symptoms as signs of severe illness, (c) neuroendocrine alterations, and (d) the influence of illness behavior (e.g., the avoidance of physical activity) on the maintenance and chronici…

Diuron environmental levels effects on marine nematodes: Assessment of ecological indices, taxonomic diversity, and functional traits

2021

Abstract Coastal marine systems are the most sensitive zones to emerging pollutants. The present study aims to investigate the effect of Diuron on the meiofaunal assemblages, collected from the Bizerte channel (Tunisia). Microcosm experiments were set up using four increasing Diuron concentrations [D1 (10 ng g−1 dry weight (DW)), D2 (50 ng g−1 DW), D3 (250 ng g−1 DW) and (1250 ng g−1 DW)] compared to non-contaminated sediments (controls) and all plots were incubated for 30 days. Our results show that Diuron-supplemented sediments provoked the significant decrease of meiofaunal abundance as well as a change in nematodes' diversity and structure composition. All univariate indices, as well as…

The internal rotational barrier of biphenyl studied with multiconfigurational second-order perturbation theory (CASPT2)

1995

A detailedab initio study of the molecular structure and rotational barriers of biphenyl has been performed. First, non-dynamical correlation effects involving the π system are taken into account at the CASSCF level. These wave functions are subsequently employed as reference functions in a multiconfigurational second-order perturbation treatment (CASPT2). The performance single-reference approaches is in addition analysed. The molecular geometries of biphenyl in twisted, coplanar, and perpendicular conformations have been optimized at the CASSCF level. A rotational angle of 44.3° is predicted for the minimum energy conformer in agreement with gas-phase electron diffraction data (44.4±1.2°)…

Neurocognitive endophenotypes in schizophrenia and bipolar disorder: A systematic review of longitudinal family studies

2018

Although there is substantial evidence supporting the existence of neurocognitive impairment in patients diagnosed with schizophrenia (SZ) and bipolar disorder (BD), few studies have explored the field from an endophenotypic perspective. The present systematic review sought to identify longitudinal family studies exploring suitable neurocognitive endophenotypes in unaffected relatives of patients with SZ and/or BD. Following the PRISMA statement, only five follow-up studies met the inclusion criteria, comprising 79 SZ patients, 159 SZ unaffected relatives of SZ, 131 BD patients, 77 unaffected relatives of BD, and 248 controls. Verbal memory, auditory attention, face memory and emotion proce…

Sexual Dysfunction and Mood Stabilizers in Long-Term Stable Patients With Bipolar Disorder.

2020

Abstract Background In addition to factors intrinsic to bipolar disorder (BD), sexual functioning (SF) can be affected by extrinsic causes, such as psychotropic drugs. However, the effect of mood stabilizers on SF and quality of life (QoL) is an underexplored research area. Aim To analyze SF in BD outpatients in euthymia for at least 6 months treated only with mood stabilizers and the association between SF and QoL. Methods A multicenter cross-sectional study was conducted in 114 BD outpatients treated with (i) lithium alone (L group); (ii) anticonvulsants alone (valproate or lamotrigine; A group); (iii) lithium plus anticonvulsants (L+A group); or (iv) lithium plus benzodiazepines (L+B gro…

A computational study of some electric and magnetic properties of gaseous BF3 and BCl3

2005

We present the results of an extended computational study of the electric and magnetic properties connected to Cotton-Mouton birefringences, on the trifluoro- and trichloroborides in the gas phase. The electric dipole polarizabilities, magnetizabilities, quadrupole moments, and higher-order hypersusceptibilities—expressed as quadratic and cubic frequency-dependent response functions—are computed within Hartree-Fock, density-functional, and coupled-cluster response theories employing singly and doubly augmented correlation-consistent basis sets and London orbitals in the magnetic property calculations. The results, which illustrate the capability of time-dependent density-functional theory f…

DiP223: Strongly temperature dependent electro-optic coefficients in BaTiO3

1992

Abstract By means of a Senarmont set up and a very sensitive method, electrooptic coefficients in BaTiO3 are accurately determined from the phase measurement of the retardation Γ due to the electric field induced birefringence of the crystal. Electro-optic properties are investigated as a function of temperature around room temperature. A very large value of the coefficient r42 is found, in agreement with previous investigations. In addition, this coefficient is shown to be very sensitive to the temperature even for a very small change. The importance of both the thermo-optic effect and the thermal variation of electro-optic properties is pointed out for device applications of BaTiO3.