Ground or Excited State: a State-Specific Variational Quantum Eigensolver for Them All

Variational Quantum Eigensolver (VQE) provides a lucrative platform to determine molecular energetics in near-term quantum devices. While the VQE is traditionally tailored to determine the ground state wavefunction with the underlying Rayleigh-Ritz principle, the access to specific symmetry-adapted excited states remains elusive. This often requires high depth circuit or additional ancilla qubits along with prior knowledge of the ground state wavefunction. We propose a unified VQE framework that treats the ground and excited states in the same footings. With the knowledge of the irreducible representations of the spinorbitals, we construct a multi-determinantal reference that is adapted to a given spatial symmetry where additionally, the determinants are entangled through appropriate Clebsch-Gordan coefficients to ensure the desired spin-multiplicity. We introduce the notion of totally symmetric, spin-scalar unitary which maintains the purity of the reference at each step of the optimization. The state-selectivity safeguards the method against any variational collapse while leading to any targeted low-lying eigenroot of arbitrary symmetry. The direct access to the excited states shields our approach from the cumulative error that plagues excited state calculations in a quantum computer and with few parameter count, it is expected to be realized in near-term quantum devices.Comment: 12 pages, 5 figure

Techno-economic and environmental analyses of hybrid renewable energy systems for a remote location employing machine learning models

This article offers a detailed investigation into the technical, economic along with environmental performance of four configurations of hybrid renewable energy systems (HRESs), aiming at supplying renewable electricity to a remote location, Henry Island in India. The study explores combinations involving photovoltaic (PV) panels, wind turbines, biogas generators, batteries, and converters, while evaluating their economic, technical, and environmental performance. The economic analysis yield that among all the systems examined, the PV, wind turbine, biogas generator, battery, and converter integrated configuration stands out with highly favourable results, showcasing the minimal value of levelized cost of electricity (LCOE) at $0.4224 per kWh and the lowest net present cost (NPC) at$6.41 million. However, technical analysis yield that the configuration comprising wind turbines, PV panels, converters, and battery yields a maximum excess electricity output of 2,838,968 kWh/yr. Additionally, machine learning techniques are employed to analyse economic and environmental performance data. The study shows Bilayered Neural Network model achieves exceptional accuracy in predicting LCOE, while the Medium Neural Network model proves to be the most accurate in predicting environmental performance. These findings provide valuable perception into the design and optimisation of HRES systems for off-grid applications in remote regions, taking into account their technical, economic, and environmental aspects

A wastewater bacterium 'Bacillus' sp. KUJM2 acts as an agent for remediation of potentially toxic elements and promoter of plant ('Lens culinaris') growth

This study investigated the role of an allochthonous Gram-positive wastewater bacterium (Bacillus sp. KUJM2) selected through rigorous screening, for the removal of potentially toxic elements (PTEs; As, Cd, Cu, Ni) and promotion of plant growth under PTE-stress conditions. The dried biomass of the bacterial strain removed PTEs (5 mg L−1) from water by 90.17–94.75 and 60.4–81.41%, whereas live cells removed 87.15–91.69 and 57.5–78.8%, respectively, under single-PTE and co-contaminated conditions. When subjected to a single PTE, the bacterial production of indole-3-acetic acid (IAA) reached the maxima with Cu (67.66%) and Ni (64.33%), but Cd showed an inhibitory effect beyond 5 mg L−1 level. The multiple-PTE treatment induced IAA production only up to 5 mg L−1 beyond which inhibition ensued. Enhanced germination rate, germination index and seed production of lentil plant (Lens culinaris) under the bacterial inoculation indicated the plant growth promotion potential of the microbial strain. Lentil plants, as a result of bacterial inoculation, responded with higher shoot length (7.1–27.61%), shoot dry weight (18.22–36.3%) and seed production (19.23–29.17%) under PTE-stress conditions. The PTE uptake in lentil shoots decreased by 67.02–79.85% and 65.94–78.08%, respectively, under single- and multiple-PTE contaminated conditions. Similarly, PTE uptake was reduced in seeds up to 72.82–86.62% and 68.68–85.94%, respectively. The bacteria-mediated inhibition of PTE translocation in lentil plant was confirmed from the translocation factor of the respective PTEs. Thus, the selected bacterium (Bacillus sp. KUJM2) offered considerable potential as a PTE remediating agent, plant growth promoter and regulator of PTE translocation curtailing environmental and human health risks

Purification of immunoglobulin Y from egg yolk using thermoresponsive aqueous micellar two-phase systems comprising ionic liquids

Immunoglobulin Y (IgY) represents an important class of antibodies, being present in egg yolk, with relevant medical applications and involving non-invasive methods of extraction. However, due to the complexity of egg yolk, the purification levels required for use in most medical applications demands the application of multi-step and cost-intensive techniques. Therefore, it is of upmost importance to develop a biocompatible and cost-effective downstream process to purify IgY from egg yolk. In this work, IgY was purified from the egg yolk water-soluble protein fraction (WSPF) by the application of thermoresponsive aqueous micellar two-phase systems (AMTPS) composed of the non-ionic surfactant Triton X-114 and surface-active ionic liquids (SAILs) as co-surfactants. The best thermoresponsive systems allowed, in a single step, to recover IgY in the surfactant-poor phase with a purity level of 69%, and up to 73% if consecutive extraction cycles are performed, while maintaining the structural integrity of the antibodies. Considering these results, a downstream process was designed and proposed, consisting of four main steps: (i) recovery of the WSPF; (ii) purification of IgY by applying AMTPS; (iii) isolation of the IgY from the main solvents using an ultrafiltration step; (iv) recycling of the AMTPS phase-forming components by precipitating the contaminant proteins.publishe

On the Growth of Iterated Entire Functions

We consider iteration of two entire functions of (p , q)-order and study some growth properties of iterated entire functions to generalise some earlier results

Noise-independent Route towards the Genesis of a COMPACT Ansatz for Molecular Energetics: a Dynamic Approach

Recent advances in quantum information and quantum science have inspired the development of various compact dynamic structured ans\"{a}tze that are expected to be realizable in the Noisy Intermediate-Scale Quantum (NISQ) devices. However, such ans\"{a}tze construction strategies hitherto developed involve considerable measurements, and thus they deviate significantly in NISQ platform from their ideal structures. Therefore, it is imperative that the usage of quantum resources must be minimized while retaining the expressivity and dynamical structure of the ansatz that can adapt itself depending on the degree of correlation. We propose a novel ansatz construction strategy based on the \textit{ab-initio} many-body perturbation theory that requires \textit{no} pre-circuit measurement and thus it remains structurally unaffected by any hardware noise. The accuracy and quantum complexity associated with the ansatz are solely dictated by a pre-defined perturbative order as desired and hence are tunable. Furthermore, the underlying perturbative structure of the ansatz construction pipeline enables us to decompose any high-rank excitation that appears in higher perturbative orders into the product of various low-rank operators, and it thus keeps the execution gate-depth to its minimum. With a number of challenging applications on strongly correlated systems, we demonstrate that our ansatz performs significantly better, both in terms of accuracy, parameter count and circuit depth, in comparison to the allied unitary coupled cluster based ans\"{a}tze.Comment: 12 pages, 3 figure

Expanding the Reactivity of Flavin Dependent Halogenases Toward Olefins via Enantioselective Intramolecular Haloetherification and Chemoenzymatic Oxidative Rearrangements

Of the different classes of halogenases characterized to date, flavin dependent halogenases (FDHs) are most commonly associated with site-selective halogenation of electron rich arenes and enol(ate) moieties in the biosynthesis of halogenated natural products. This capability has made them attractive biocatalysts, and extensive efforts have been devoted to both discovering and engineering these enzymes for different applications. We have established that engineered FDHs can catalyze different enantioselective halogenation processes, including halolactonization of simple alkenes with a tethered carboxylate nucleophile. In this study, we expand the scope of this reaction to include alcohol nucleophiles and a greater diversity of alkene substitution patterns to access a variety of chiral tetrahydrofurans. We also demonstrate that FDHs can be interfaced with ketoreductases to enable halocyclization using ketone substrates in one-pot cascade reactions and that the halocyclization products can undergo subsequent rearrangements to form novel hydroxylated and halogenated products. Together, these advances expand the utility of FDHs for enantio- and diastereoselective olefin functionalization

Directed Evolution of Flavin-Dependent Halogenases for Atroposelective Halogenation of 3-Aryl-4(3H)-quinazolinones via Kinetic or Dynamic Kinetic Resolution

In this study, we engineer a variant of the flavin-dependent halogenase RebH that catalyzes site- and atroposelective halogenation of 3-aryl-4(3H)-quinazolinones via kinetic or dynamic kinetic resolution. The required directed evolution uses a combination of random and site-saturation mutagenesis, substrate walking using two probe substrates, and a two-tiered screening approach involving analysis of variant conversion and then enantioselectivity of improved variants. The resulting variant, 3-T, provides >99:1 e.r. for the (M)-atropisomer of the major brominated product, 25-fold improved conversion, and 91-fold improved site-selectivity relative to the parent enzyme on the probe substrate used in the final rounds of evolution. This high activity and selectivity translates well to several additional substrates with varied steric and electronic properties. Computational modeling and docking simulations are used to rationalize the effects of key mutations on substrate scope and site- and atroposelectivity. Given the range of substrates that have been used for atroposelective synthesis via electrophilic halogenation, these results suggest that FDHs could find many additional applications for atroposelective catalysis. More broadly, this study highlights how RebH can be engineered to accept structurally diverse substrates that enable its use for enantioselective catalysis