Accurate Quantum Monte Carlo Forces for Machine-Learned Force Fields: Ethanol as a Benchmark.

Quantum Monte Carlo (QMC) is a powerful method to calculate accurate energies and forces for molecular systems. In this work, we demonstrate how we can obtain accurate QMC forces for the fluxional ethanol molecule at room temperature by using either multideterminant Jastrow-Slater wave functions in variational Monte Carlo or just a single determinant in diffusion Monte Carlo. The excellent performance of our protocols is assessed against high-level coupled cluster calculations on a diverse set of representative configurations of the system. Finally, we train machine-learning force fields on the QMC forces and compare them to models trained on coupled cluster reference data, showing that a force field based on the diffusion Monte Carlo forces with a single determinant can faithfully reproduce coupled cluster power spectra in molecular dynamics simulations.

[Modern conception of the pathogenesis of neurodegenerative diseases and therapeutic strategy]. / Sovremennaia kontseptsiia patogeneza neirodegenerativnykh zabolevanii i strategiia terapii.

Here we discuss the pathogenesis of the inflammatory and degenerative nervous system disorders on the example of Parkinson's disease, Alzheimer's disease, multiple sclerosis. Common mechanisms of neurodegeneration in these diseases are reviewed. The role of neurodegeneration as the main process leading to the resistant disability of patients with multiple sclerosis is discussed. The authors consider a contribution of inflammatory process and chronic infection to the manifestation and progressing of a neurodegenerative disease and discuss the use of treatment not usually indicated including interferon, anti-inflammatory drugs, statin, vitamin D, monoclonal antibodies, correction of the intestinal microbiota in Parkinson's disease and Alzheimer's disease.

[MRI morphometry of neuroplastic changes in the brain after conservative treatment of traumatic brachial plexopathy]. / Magnitno-rezonansnaia morfometriia neiroplasticheskikh izmenenii golovnogo mozga pri konservativnoi terapii travmaticheskoi plechevoi pleksopatii.

AIM: To identify neuroplastic changes in the brain structures during treatment of traumatic axonotomy of the brachial plexus (the pathology of peripheral nervous system). MATERIAL AND METHODS: MRI morphometry of white and grey matter was studied in 62 patients with traumatic axonotomy of the brachial plexus. RESULTS: There were correlations between the thickness of sensorimotor cortex, morphometric parameters (volume, diffusion, fractional anisotropy) of subcortical formations (corticospinal tracts, the forceps minor), severity of neurological deficit and dynamics of clinical course depending on the therapeutic strategy. CONCLUSION: The results expand the current view on central mechanisms of posttraumatic axon regeneration on the model of traumatic brachial plexopathy and establish a neuromodulative effect of neuromidin and noofen. Some morphometric parameters may be used as the markers of reactive neuroplastic processes in the central nervous system.