Under suitable assumptions, the quantum-phase-estimation (QPE) algorithm is able to achieve Heisenberg-limited precision scaling in estimating the ground-state energy. However, QPE requires a large ...number of ancilla qubits and a large circuit depth, as well as the ability to perform inverse quantum Fourier transform, making it expensive to implement on an early fault-tolerant quantum computer. We propose an alternative method to estimate the ground-state energy of a Hamiltonian with Heisenberg-limited precision scaling, which employs a simple quantum circuit with one ancilla qubit, and a classical postprocessing procedure. Besides the ground-state energy, our algorithm also produces an approximate cumulative distribution function of the spectral measure, which can be used to compute other spectral properties of the Hamiltonian.
Preparing the ground state of a given Hamiltonian and estimating its ground energy are important but computationally hard tasks. However, given some additional information, these problems can be ...solved efficiently on a quantum computer. We assume that an initial state with non-trivial overlap with the ground state can be efficiently prepared, and the spectral gap between the ground energy and the first excited energy is bounded from below. With these assumptions we design an algorithm that prepares the ground state when an upper bound of the ground energy is known, whose runtime has a logarithmic dependence on the inverse error. When such an upper bound is not known, we propose a hybrid quantum-classical algorithm to estimate the ground energy, where the dependence of the number of queries to the initial state on the desired precision is exponentially improved compared to the current state-of-the-art algorithm proposed in Ge et al. 2019. These two algorithms can then be combined to prepare a ground state without knowing an upper bound of the ground energy. We also prove that our algorithms reach the complexity lower bounds by applying it to the unstructured search problem and the quantum approximate counting problem.
We present a quantum eigenstate filtering algorithm based on quantum signal processing (QSP) and minimax polynomials. The algorithm allows us to efficiently prepare a target eigenstate of a given ...Hamiltonian, if we have access to an initial state with non-trivial overlap with the target eigenstate and have a reasonable lower bound for the spectral gap. We apply this algorithm to the quantum linear system problem (QLSP), and present two algorithms based on quantum adiabatic computing (AQC) and quantum Zeno effect respectively. Both algorithms prepare the final solution as a pure state, and achieves the near optimal
O
~
(
d
κ
log
(
1
/
ϵ
)
)
query complexity for a
d
-sparse matrix, where
κ
is the condition number, and
ϵ
is the desired precision. Neither algorithm uses phase estimation or amplitude amplification.
Abstract
Owing to inevitable thermal/moisture instability for organic–inorganic hybrid perovskites, pure inorganic perovskite cesium lead halides with both inherent stability and prominent ...photovoltaic performance have become research hotspots as a promising candidate for commercial perovskite solar cells. However, it is still a serious challenge to synthesize desired cubic cesium lead iodides (CsPbI
3
) with superior photovoltaic performance for its thermodynamically metastable characteristics. Herein, polymer poly-vinylpyrrolidone (PVP)-induced surface passivation engineering is reported to synthesize extra-long-term stable cubic CsPbI
3
. It is revealed that acylamino groups of PVP induce electron cloud density enhancement on the surface of CsPbI
3
, thus lowering surface energy, conducive to stabilize cubic CsPbI
3
even in micrometer scale. The cubic-CsPbI
3
PSCs exhibit extra-long carrier diffusion length (over 1.5 μm), highest power conversion efficiency of 10.74% and excellent thermal/moisture stability. This result provides important progress towards understanding of phase stability in realization of large-scale preparations of efficient and stable inorganic PSCs.
Transcription factors (TFs) coordinate the on-and-off states of gene expression typically in a combinatorial fashion. Studies from embryonic stem cells and other cell types have revealed that a ...clique of self-regulated core TFs control cell identity and cell state. These core TFs form interconnected feed-forward transcriptional loops to establish and reinforce the cell-type-specific gene-expression program; the ensemble of core TFs and their regulatory loops constitutes core transcriptional regulatory circuitry (CRC). Here, we summarize recent progress in computational reconstitution and biologic exploration of CRCs across various human malignancies, and consolidate the strategy and methodology for CRC discovery. We also discuss the genetic basis and therapeutic vulnerability of CRC, and highlight new frontiers and future efforts for the study of CRC in cancer. Knowledge of CRC in cancer is fundamental to understanding cancer-specific transcriptional addiction, and should provide important insight to both pathobiology and therapeutics.
Polyethylenimine (PEI)‐grafted silica nanoparticles were fabricated and characterized for the electrostatic immobilization of a CO2 conversion enzyme. PEI was supposed to serve as a carbonic ...anhydrase mimic for CO2 capture and conversion to HCO3− (the optimal substrate of many CO2 conversion enzymes) and was proved to assist phosphoenolpyruvate carboxylase to form a dual‐enzyme cascade system for CO2 conversion. The immobilized enzyme not only presented better thermostability, pH tolerance, and storage stability, but also enhanced the specific activity (three‐ and fourfold for HCO3− and CO2 as the substrates, respectively), with good reusability and low cost. It was proven that PEI‐grafted nanoparticles are highly efficient nanocarriers for immobilizing CO2‐converting enzymes in industrial applications.
Polyethyleneimine was grafted onto silica nanoparticles (SNP‐PEI) for the electrostatic immobilization of phosphoenolpyruvate carboxylase (PEPCase), a CO2 conversion enzyme. SNP‐PEI facilitated enzymatic CO2 conversion by both increasing the enzyme stability and mimicking carbonic anhydrase to catalyze CO2 turnover to HCO3−, which is the better substrate of PEPCase.
There are no global screening recommendations for esophageal squamous cell carcinoma (ESCC). Endoscopic screening has been investigated in areas of high incidence in China since the 1970s. This study ...aimed to evaluate whether an endoscopic screening and intervention program could reduce mortality caused by ESCC.
Residents age 40 to 69 years were recruited from communities with high rates of ESCC. Fourteen villages were selected as the intervention communities. Ten villages not geographically adjacent to intervention villages were selected for comparison. Participants in the intervention group were screened once by endoscopy with Lugol's iodine staining, and those with dysplasia or occult cancer were treated. All intervention participants and a sample consisting of one tenth of the control group completed questionnaires. We compared cumulative ESCC incidence and mortality between the two groups.
Three thousand three hundred nineteen volunteers (48.62%) from an eligible population of 6,827 were screened in the intervention group. Seven hundred ninety-seven volunteers from an eligible population of 6,200 in the control group were interviewed. Six hundred fifty-two incident and 542 fatal ESCCs were identified during the 10-year follow-up. A reduction in cumulative mortality in the intervention group versus the control group was apparent (3.35% v 5.05%, respectively; P < .001). Furthermore, the intervention group had a significantly lower cumulative incidence of ESCC versus the control group (4.17% v 5.92%, respectively; P < .001).
We showed that endoscopic screening and intervention significantly reduced mortality caused by esophageal cancer. Detection and treatment of preneoplastic lesions also led to a reduction in the incidence of this highly fatal cancer.
Ovule initiation is a key step that strongly influences ovule number and seed yield. Notably, mutants with enhanced brassinosteroid (BR) and cytokinin (CK) signaling produce more ovules and have a ...higher seed number per silique (SNS) than wild‐type plants. Here, we crossed BR‐ and CK‐related mutants to test whether these phytohormones function together in ovule initiation. We determined that simultaneously enhancing BR and CK contents led to higher ovule and seed numbers than enhancing BR or CK separately, and BR and CK enhanced each other. Further, the BR‐response transcription factor BZR1 directly interacted with the CK‐response transcription factor ARABIDOPSIS RESPONSE REGULATOR1 (ARR1). Treatments with BR or BR plus CK strengthened this interaction and subsequent ARR1 targeting and induction of downstream genes to promote ovule initiation. Enhanced CK signaling partially rescued the reduced SNS phenotype of BR‐deficient/insensitive mutants whereas enhanced BR signaling failed to rescue the low SNS of CK‐deficient mutants, suggesting that BR regulates ovule initiation and SNS through CK‐mediated and ‐independent pathways. Our study thus reveals that interaction between BR and CK promotes ovule initiation and increases seed number, providing important clues for increasing the seed yield of dicot crops.
Brassinosteroid and cytokinin co‐promote ovule initiation by enhancing the expression of positive regulators via a direct interaction of the transcription factors BRASSINAZOLERESISTANT 1 and ARABIDOPSIS RESPONSE REGULATOR1. This mechanism gives clues to increase seed number/yield of leguminous and cruciferous crops.
A small amount of carbon nanotubes (CNTs) was added into poly(vinylidene fluoride) (PVDF)/boron nitride (BN) composites through melt blending processing. The thermal conductivity, microstructure ...changes including the crystallization behavior of PVDF matrix and the dispersion states of fillers in the composites, and the electrical conductivity of the composites were comparatively investigated. The results demonstrated that compared with the PVDF/BN composites at the same BN content, the ternary PVDF/BN/CNT composites exhibited largely enhanced thermal conductivity. In the PVDF/BN/CNT composites, the crystallinity of the PVDF matrix was slightly increased while the crystal form remained invariant. BN particles exhibited homogeneous dispersion in the PVDF/BN composites, and they did not affect the rheological properties of the PVDF/BN composites when the BN content was lower than 10 wt %. The presence of CNTs did not affect the interfacial adhesion between BN and PVDF, but they facilitated the formation of denser BN/CNT network structure in the composites. The mechanisms were then proposed to explain the largely enhanced thermal conductivity of the PVDF/BN/CNT composites. Furthermore, the dielectric property measurements demonstrated that the PVDF/BN/CNT composites containing relatively low BN content exhibited a high dielectric constant with a low dielectric loss. This endowed the PVDF/BN/CNT composites with a greater potential application in the field of electronic devices.
Soft tissue sarcoma (STS) is a heterogeneous disease that arises from connective tissues. Clinical outcome of patients with advanced tumors especially de-differentiated liposarcoma and uterine ...leiomyosarcoma remains unsatisfactory, despite intensive treatment regimens including maximal surgical resection, radiation, and chemotherapy. MAP kinase-interacting serine/threonine-protein kinase 1 and 2 (MNK1/2) have been shown to contribute to oncogenic translation via phosphorylation of eukaryotic translation initiation factor 4E (eIF4E). However, little is known about the role of MNK1/2 and their downstream targets in STS. In this study, we show that depletion of either MNK1 or MNK2 suppresses cell viability, anchorage-independent growth, and tumorigenicity of STS cells. We also identify a compelling antiproliferative efficacy of a novel, selective MNK inhibitor ETC-168. Cellular responsiveness of STS cells to ETC-168 correlates positively with that of phosphorylated ribosomal protein S6 (RPS6). Mirroring MNK1/2 silencing, ETC-168 treatment strongly blocks eIF4E phosphorylation and represses expression of sarcoma-driving onco-proteins including E2F1, FOXM1, and WEE1. Moreover, combination of ETC-168 and MCL1 inhibitor S63845 exerts a synergistic antiproliferative activity against STS cells. In summary, our study reveals crucial roles of MNK1/2 and their downstream targets in STS tumorigenesis. Our data encourage further clinical translation of MNK inhibitors for STS treatment.
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