Artificial Neural Network Encoding of Molecular Wavefunction for Quantum Computing

Artificial neural networks (ANNs) for material modeling have received significant interest. We recently reported an adaptation of ANNs based on Boltzmann machine (BM) architectures to an ansatz of the multiconfigurational many-electron wavefunction, designated neural-network quantum state (NQS), for quantum chemistry calculations [Yang et al., J. Chem. Theory Comput., 2020, 16, 3513--3529]. Here, this study presents its extended formalism to a quantum algorithm that enables the preparation of the NQS through quantum gates. The descriptors of the ANN model, which are chosen as the occupancies of electronic configurations, are quantum-mechanically represented by qubits. Our algorithm may thus bring potential advantages over classical sampling-based computation employed in the previous studies. The NQS can be accurately formed using quantum-native procedures. Still, the training of the model in terms of energy minimization is efficiently performed on a classical computer; thus, our approach is a class of variational quantum eigensolver. The BM models are related to the Gibbs distribution, and our preparation procedures exploit techniques of quantum phase estimation but with no Hamiltonian evolution. The proposed algorithm is assessed by implementing it on a quantum computer simulator. Illustrative molecular calculations at the complete-active-space configuration interaction level of theory are displayed, confirming consistency with the accuracy of our previous classical approaches

Extended theoretical modeling of reverse intersystem crossing for thermally activated delayed fluorescence materials

Thermally activated delayed fluorescence (TADF) materials and multi-resonant (MR) variants are promising organic emitters that can achieve an internal electroluminescence quantum efficiency of approximately 100%. The reverse intersystem crossing (RISC) is key for harnessing triplet energies for fluorescence. Theoretical modeling is thus crucial to estimate its rate constant kRISC for material development. Herein, we present a comprehensive assessment of the theory for simulating the RISC of MR-TADF molecules within a perturbative excited-state dynamics framework. Our extended rate formula reveals the importance of the concerted effects of nonadiabatic spin-vibronic coupling and vibrationally induced spin-orbital couplings in reliably determining kRISC of MR-TADF molecules. The excited singlet-triplet energy gap is another factor influencing kRISC. We present a new scheme for gap estimation using experimental Arrhenius plots of kRISC. Erroneous behavior caused by approximations in Marcus theory is elucidated by testing 121 MR-TADF molecules. Our extended modeling offers in-depth descriptions of kRISC

Erratum: Wound healing and longevity: Lessons from long-lived \u3b1MUPA mice

In this Article, the additional affiliation is added for Arie Budovsky, a co-author of this manuscript. Erratum for Wound healing and longevity: lessons from long-lived \u3b1MUPA mice. [Aging (Albany NY). 2015

Middle age has a significant impact on gene expression during skin wound healing in male mice

The vast majority of research on the impact of age on skin wound healing (WH) compares old animals to young ones. The middle age is often ignored in biogerontological research despite the fact that many functions that decline in an age-dependent manner have starting points in mid-life. With this in mind, we examined gene expression patterns during skin WH in late middle-aged versus young adult male mice, using the head and back punch models. The rationale behind this study was that the impact of age would first be detectable at the transcriptional level. We pinpointed several pathways which were over-activated in the middle-aged mice, both in the intact skin and during WH. Among them were various metabolic, immune-inflammatory and growth-promoting pathways. These transcriptional changes were much more pronounced in the head than in the back. In summary, the middle age has a significant impact on gene expression in intact and healing skin. It seems that the head punch model is more sensitive to the effect of age than the back model, and we suggest that it should be more widely applied in aging research on wound healing

NAD+ augmentation with nicotinamide riboside improves lymphoid potential of Atm−/− and old mice HSCs

NAD+ supplementation has significant benefits in compromised settings, acting largely through improved mitochondrial function and DNA repair. Elevating NAD+ to physiological levels has been shown to improve the function of some adult stem cells, with implications that these changes will lead to sustained improvement of the tissue or system. Here, we examined the effect of elevating NAD+ levels in models with reduced hematopoietic stem cell (HSC) potential, ATM-deficient and aged WT mice, and showed that supplementation of nicotinamide riboside (NR), a NAD+ precursor, improved lymphoid lineage potential during supplementation. In aged mice, this improved lymphoid potential was maintained in competitive transplants and was associated with transcriptional repression of myeloid gene signatures in stem and lineage-committed progenitor cells after NR treatment. However, the altered transcriptional priming of the stem cells toward lymphoid lineages was not sustained in the aged mice after NR removal. These data characterize significant alterations to the lineage potential of functionally compromised HSCs after short-term exposure to NR treatment