Relationship between Subjective Dry Mouth Feeling and Cognitive Dysfunction Assessment in Elderly in Some Areas

Objectives: The purpose of this study was to determine the relevance of cognitive impairment assessment due to subjective oral dry symptoms in older adults. Methods: After a three-month survey of patients visiting some dental hospitals in Busan from December 2019, the final 111 people were analyzed using the SPSS 26.0 program. Results: Groups with high subjective mouth dryness showed higher levels of cognitive dysfunction than those with lower subjective mouth dryness(<.001), and subjective mouth dryness showed a static correlation with the evaluation of cognitive dysfunction(r=.338, p<.01). Conclusions: Therefore, this study is considered to be a meaningful study that approaches the elderly's health problems in the aged society from various angles, and it is intended to be used as a basic data for the development of elderly health prevention programs as well as the prevention of geriatric diseases.

Effective free-fermionic form factors and the XY spin chain

We introduce effective form factors for one-dimensional lattice fermions with arbitrary phase shifts. We study tau functions defined as series of these form factors. On the one hand we perform the exact summation and present tau functions as Fredholm determinants in the thermodynamic limit. On the other hand simple expressions of form factors allow us to present the corresponding series as integrals of elementary functions. Using this approach we re-derive the asymptotics of static correlation functions of the XY quantum chain at finite temperature.

Revealing the Nature of Electron Correlation in Transition Metal Complexes with Symmetry-Breaking and Chemical Intuition

The present work provides a useful framework through which theoreticians and practicing computational chemists alike can view electron correlations in transition metal complexes. We present static correlation from the perspective of simple chemical models such as ligand-field and molecular orbital theories, and an analysis of symmetry breaking suggests that it is rarely encountered in thermochemical calculations of realistic transition metal compounds (though we do reveal a few important situations in which it is relevant). The relative complexity of transition metal bonding, relative to that of typical organic compounds, places a larger burden on a theory's treatment of dynamic correlation. After recognizing that simultaneous sigma-donation and pi-backbonding can be viewed as a correlated interaction involving multiple electron pairs, we demonstrate that MP2 and related double hybrid density functionals fail to describe this type of bonding.

Revealing the Nature of Electron Correlation in Transition Metal Complexes with Symmetry-Breaking and Chemical Intuition

The present work provides a useful framework through which theoreticians and practicing computational chemists alike can view electron correlations in transition metal complexes. We present static correlation from the perspective of simple chemical models such as ligand-field and molecular orbital theories, and an analysis of symmetry breaking suggests that it is rarely encountered in thermochemical calculations of realistic transition metal compounds (though we do reveal a few important situations in which it is relevant). The relative complexity of transition metal bonding, relative to that of typical organic compounds, places a larger burden on a theory's treatment of dynamic correlation. After recognizing that simultaneous sigma-donation and pi-backbonding can be viewed as a correlated interaction involving multiple electron pairs, we demonstrate that MP2 and related double hybrid density functionals fail to describe this type of bonding.

Post-Hartree-Fock Methods and Electron Correlation: A Very Brief Overview

‘This chapter sketches how the electron correlation is treated in post-Hartree-Fock (HF) wavefunction methods. The distinction between static and dynamic correlation is explained. A configuration interaction (CI) wavefunction is a linear combination of several or many Slater determinants (SDs). Following a HF calculation, different SDs can be constructed by replacing 1, 2, 3, … occupied orbitals in the HF wavefunction with 1, 2, 3,… unoccupied or virtual orbitals, leading to pseudo-excited electron configurations at the singles, doubles, triples, … (S, D, T, …) level. The virtual orbitals are usually available as a by-product of the HF calculation in a basis set. Full CI (FCI) considers all possible substitutions, up to N-fold for an N-electron system. FCI is impractical for all but the smallest molecules. CI truncated at a lower level, e.g. S and D, suffers from lack of size extensitivity. Truncated coupled-cluster (CC) is size extensive. Open-shell systems generally require a multi-reference treatment. The chapter concludes with a treatment of the static correlation in the bond breaking of H2.

Bridge Surface Roughness Identified from the Displacement Influence Lines of the Contact Points by Two Connected Vehicles

In this study, a new, effective procedure is proposed for identifying the surface roughness from the responses recorded of two connected test vehicles moving over the bridge. Central to this study is the proposal of a simple static correlation formula for relating the dynamic deflections of the two vehicles’s contact points on the bridge, via the displacement influence lines (DILs). With the aid of this relation, the roughness formula for estimating the bridge surface profile is derived using the responses of the leading and following vehicles. It does not require any prior knowledge of the dynamic properties of the bridge. The efficacy of the proposed procedure is validated for both the simple and three-span continuous beams by the finite element method (FEM). Also, a parametric study is conducted for various physical properties of the test vehicles. It is confirmed that the roughness profiles back-calculated from the proposed formula agree excellently with the assumed ones for both the simple and continuous beams. For use in practice, the two connected test vehicles should not be designed too heavy and not to move at too fast speeds, in order to reduce the impact on the bridge.