7 research outputs found
Measurement-efficient quantum Krylov subspace diagonalisation
The Krylov subspace methods, being one category of the most important
classical numerical methods for linear algebra problems, their quantum
generalisation can be much more powerful. However, quantum Krylov subspace
algorithms are prone to errors due to inevitable statistical fluctuations in
quantum measurements. To address this problem, we develop a general theoretical
framework to analyse the statistical error and measurement cost. Based on the
framework, we propose a quantum algorithm to construct the Hamiltonian-power
Krylov subspace that can minimise the measurement cost. In our algorithm, the
product of power and Gaussian functions of the Hamiltonian is expressed as an
integral of the real-time evolution, such that it can be evaluated on a quantum
computer. We compare our algorithm with other established quantum Krylov
subspace algorithms in solving two prominent examples. It is shown that the
measurement number in our algorithm is typically to times
smaller than other algorithms. Such an improvement can be attributed to the
reduced cost of composing projectors onto the ground state. These results show
that our algorithm is exceptionally robust to statistical fluctuations and
promising for practical applications.Comment: 18 pages, 5 figure
Quantum algorithms for optimal effective theory of many-body systems
A common situation in quantum many-body physics is that the underlying
theories are known but too complicated to solve efficiently. In such cases, one
usually builds simpler effective theories as low-energy or large-scale
alternatives to the original theories. Here the central tasks are finding the
optimal effective theories among a large number of candidates and proving their
equivalence to the original theories. Recently quantum computing has shown the
potential of solving quantum many-body systems by exploiting its inherent
parallelism. It is thus an interesting topic to discuss the emergence of
effective theories and design efficient tools for finding them based on the
results from quantum computing. As the first step towards this direction, in
this paper, we propose two approaches that apply quantum computing to find the
optimal effective theory of a quantum many-body system given its full
Hamiltonian. The first algorithm searches the space of effective Hamiltonians
by quantum phase estimation and amplitude amplification. The second algorithm
is based on a variational approach that is promising for near-future
applications.Comment: 8 pages, 4 figure
Development of Acidification-resistant Organic Fertilizer for Improvement of Acid Red Soil in Guangxi
The soil in Guangxi has been severely acidified, restricting sustainable development of agriculture. In this paper, based on the screening of organic fertilizer additives, a method for the production of acidification-resistant organic fertilizer specific for acid red soil improvement was proposed, and the developed acidification-resistant organic fertilizer was used in sugarcane experiment. The results showed that in the treatment that the specific acidification-resistant organic fertilizer was applied, the yield of sugarcane significantly increased, the pH value of soil effectively increased, the physical and chemical properties of soil improved, and the contents of microorganisms and available nutrients in soil increased
Recent Advances in SELEX Technology and Aptamer Applications in Biomedicine
Aptamers are short DNA/RNA oligonucleotides capable of binding to target molecules with high affinity and specificity. The process of selecting an aptamer is called Systematic Evolution of Ligands by Exponential Enrichment (SELEX). Thanks to the inherit merits, aptamers have been used in a wide range of applications, including disease diagnosis, targeted delivery agents and therapeutic uses. To date, great achievements regarding the selection, modifications and application of aptamers have been made. However, few aptamer-based products have already successfully entered into clinical and industrial use. Besides, it is still a challenge to obtain aptamers with high affinity in a more efficient way. Thus, it is important to comprehensively review the current shortage and achievement of aptamer-related technology. In this review, we first present the limitations and notable advances of aptamer selection. Then, we compare the different methods used in the kinetic characterization of aptamers. We also discuss the impetus and developments of the clinical application of aptamers
A bimolecular modification strategy for developing long-lasting bone anabolic aptamer
The molecular weight of nucleic acid aptamers (20 kDa) is lower than the cutoff threshold of the renal filtration (30–50 kDa), resulting in a very short half-life, which dramatically limits their druggability. To address this, we utilized 3-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-N-(4-hydroxy-2-oxo-2H-chromen-6-yl)propenamide (HC) and 12-((2,5-dioxopyrrolidin-1-yl)oxy)-12-oxododecanoic acid (DA), two newly designed coupling agents, for synergistic binding to human serum albumin (HSA). Both HC and DA are conjugated to a bone anabolic aptamer (Apc001) against sclerostin to form an Apc001OC conjugate with high binding affinity to HSA. Notably, HC and DA could synergistically facilitate prolonging the half-life of the conjugated Apc001 and promoting its bone anabolic potential. Using the designed blocking peptides, the mechanism studies indicate that the synergistic effect of HC-DA on pharmacokinetics and bone anabolic potential of the conjugated Apc001 is achieved via their synergistic binding to HSA. Moreover, biweekly Apc001OC at 50 mg/kg shows comparable bone anabolic potential to the marketed sclerostin antibody given weekly at 25 mg/kg. This proposed bimolecular modification strategy could help address the druggability challenge for aptamers with a short half-life