477 research outputs found

    Experimentally obtaining the Likeness of Two Unknown Quantum States on an NMR Quantum Information Processor

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    Recently quantum states discrimination has been frequently studied. In this paper we study them from the other way round, the likeness of two quantum states. The fidelity is used to describe the likeness of two quantum states. Then we presented a scheme to obtain the fidelity of two unknown qubits directly from the integral area of the spectra of the assistant qubit(spin) on an NMR Quantum Information Processor. Finally we demonstrated the scheme on a three-qubit quantum information processor. The experimental data are consistent with the theoretical expectation with an average error of 0.05, which confirms the scheme.Comment: 3 pages, 4 figure

    Generating Giant and Tunable Nonlinearity in a Macroscopic Mechanical Resonator from Chemical Bonding Force

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    Nonlinearity in macroscopic mechanical system plays a crucial role in a wide variety of applications, including signal transduction and processing, synchronization, and building logical devices. However, it is difficult to generate nonlinearity due to the fact that macroscopic mechanical systems follow the Hooke's law and response linearly to external force, unless strong drive is used. Here we propose and experimentally realize a record-high nonlinear response in macroscopic mechanical system by exploring the anharmonicity in deforming a single chemical bond. We then demonstrate the tunability of nonlinear response by precisely controlling the chemical bonding interaction, and realize a cubic elastic constant of \mathversion{bold}2×1018 N/m32 \times 10^{18}~{\rm N}/{\rm m^3}, many orders of magnitude larger in strength than reported previously. This enables us to observe vibrational bistate transitions of the resonator driven by the weak Brownian thermal noise at 6~K. This method can be flexibly applied to a variety of mechanical systems to improve nonlinear responses, and can be used, with further improvements, to explore macroscopic quantum mechanics

    Earthworms Modulate Impacts of Soil Heterogeneity on Plant Growth at Different Spatial Scales

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    [Abstract] Soil heterogeneity (uneven distribution of soil nutrients and/or other properties) is ubiquitous in nature and can greatly affect plant growth. As earthworm activity can influence nutrient redistribution in the soil, we hypothesize that earthworms may alter the effect of soil heterogeneity on plant growth and this effect may depend on the scale of soil heterogeneity. To test these hypotheses, we grew the clonal grass Leymus chinensis in three soil treatments (heterogeneous large vs. heterogeneous small patch vs. homogeneous soil treatment) with or without earthworms [i.e., Eisenia fetida Savigny (Lumbricidae, epigeic redworm)]. In the heterogeneous treatments, the soil consisted of patches with and without 15N-labeled litter (referred to as high- and low-quality patches, respectively), and in the homogeneous treatment, the soil was an even mixture of the two types of soil patches. Biomass of L. chinensis was significantly higher in the high- than in the low-quality patches, showing the foraging response; this foraging response occurred at both scales and under both earthworm treatments. Compared to the homogeneous treatment, the heterogeneous large patch treatment increased biomass of L. chinensis without earthworms, but decreased it with earthworms. In contrast, biomass of L. chinensis in the heterogeneous small patch treatment did not differ from that in the homogeneous treatment, irrespective of earthworms. Belowground biomass was much greater in the heterogeneous small than in the heterogeneous large patch treatment without earthworms, but it did not differ between these two scale treatments with earthworms. In the heterogeneous treatments, soil 15N was greater in the high- than in the low-quality patches, but this effect became much weaker with than without earthworms, suggesting that earthworm activity homogenized the soil. We conclude that earthworms can change the impact of soil heterogeneity on plant growth via homogenizing the soil, and that this effect of earthworms varies with patch scale. Such scale-dependent interactive effects of soil heterogeneity and earthworms could be a potential mechanism modulating plant community structure and productivity.This study was supported by the National Natural Science Foundation of China (31800341) and the Ten-Thousand-Talent Program of Zhejiang Province (2018R52016)China. National Natural Science Foundation of China; 31800341China. Ten-Thousand-Talent Program of Zhejiang Province; 2018R5201

    An Architecture of Deterministic Quantum Central Processing Unit

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    We present an architecture of QCPU(Quantum Central Processing Unit), based on the discrete quantum gate set, that can be programmed to approximate any n-qubit computation in a deterministic fashion. It can be built efficiently to implement computations with any required accuracy. QCPU makes it possible to implement universal quantum computation with a fixed, general purpose hardware. Thus the complexity of the quantum computation can be put into the software rather than the hardware.Comment: 4 pages, 4 figures, 1 tabl

    Recombinant Rabbit Leukemia Inhibitory Factor and Rabbit Embryonic Fibroblasts Support the Derivation and Maintenance of Rabbit Embryonic Stem Cells

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    Abstract The rabbit is a classical experimental animal species. A major limitation in using rabbits for biomedical research is the lack of germ-line-competent rabbit embryonic stem cells (rbESCs). We hypothesized that the use of homologous feeder cells and recombinant rabbit leukemia inhibitory factor (rbLIF) might improve the chance in deriving germ-line-competent rbES cells. In the present study, we established rabbit embryonic fibroblast (REF) feeder layers and synthesized recombinant rbLIF. We derived a total of seven putative rbESC lines, of which two lines (M5 and M23) were from culture Condition I using mouse embryonic fibroblasts (MEFs) as feeders supplemented with human LIF (hLIF) (MEF+hLIF). Another five lines (R4, R9, R15, R21, and R31) were derived from Condition II using REFs as feeder cells supplemented with rbLIF (REF+rbLIF). Similar derivation efficiency was observed between these two conditions (8.7% vs. 10.2%). In a separate experiment with 2?3 factorial design, we examined the effects of feeder cells (MEF vs. REF) and LIFs (mLIF, hLIF vs. rbLIF) on rbESC culture. Both Conditions I and II supported satisfactory rbESC culture, with similar or better population doubling time and colony-forming efficiency than other combinations of feeder cells with LIFs. Rabbit ESCs derived and maintained on both conditions displayed typical ESC characteristics, including ESC pluripotency marker expression (AP, Oct4, Sox2, Nanog, and SSEA4) and gene expression (Oct4, Sox2, Nanog, c-Myc, Klf4, and Dppa5), and the capacity to differentiate into three primary germ layers in vitro. The present work is the first attempt to establish rbESC lines using homologous feeder cells and recombinant rbLIF, by which the rbESCs were derived and maintained normally. These cell lines are unique resources and may facilitate the derivation of germ-line-competent rbESCs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98439/1/cell%2E2012%2E0001.pd

    Application of quantitative real-time PCR to detect Mink Circovirus in minks, foxes and raccoon dogs in northern China

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    Mink circovirus disease caused by Mink Circovirus (MiCV) is a serious infectious disease of mink that has become prevalent in recent years in China, severely affecting the reproductive performance of mink and causing significant economic losses to farms. To date, there have been few studies on MiCV, its pathogenic mechanism is not clear, and there is no effective vaccine or drug to prevent and control the disease. Therefore, it is necessary to establish a rapid and reliable molecular diagnostic method, which would aid future studies of this novel virus. In our study, we developed a sensitive and specific TaqMan-based quantitative real-time PCR assay targeting the MiCV Cap gene. The assay showed no cross-reaction with other tested animal viruses. The assay is highly sensitive, with a detection limit of as low as 10 plasmid DNA copies and 2.38 × 10−2 pg of viral DNA. The intra and inter--assay coefficients of variation were both low. The positive detection rate of MiCV in clinical samples from minks, foxes, and raccoon dogs were 58.8% (133/226), 50.7% (72/142), and 42.2% (54/128), respectively, giving a total positive detection rate of 52.2% (259/496). Higher contamination levels were observed in samples from the environment in direct or indirect contact with animals, with a total positive detection rate of 75.1% (220/293). These epidemiological results showed that minks, foxes, and raccoon dogs had high infection rates of MiCV. This was also the first study to detect MiCV on the ground and equipment of fur-bearing animal farms. Our assay is highly sensitive and specific for the diagnosis and quantification of MiCV, and should provide a reliable real-time tool for epidemiological and pathogenetic study of MiCV infection

    Prevalence of Mycobacterium bovis in deer in mainland China: a systematic review and meta-analysis

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    BackgroundDeer tuberculosis is a chronic zoonotic infectious disease, despite the existence of socio-economic and zoonotic risk factors, but at present, there has been no systematic review of deer tuberculosis prevalence in mainland China. The aim of this meta-analysis was to estimate the overall prevalence of deer TB in mainland China and to assess possible associations between potential risk factors and the prevalence of deer tuberculosis.MethodologyThis study was searched in six databases in Chinese and English, respectively (1981 to December 2023). Four authors independently reviewed the titles and abstracts of all retrieved articles to establish the inclusion exclusion criteria. Using the meta-analysis package estimated the combined effects. Cochran’s Q-statistic was used to analyze heterogeneity. Funnel plots (symmetry) and used the Egger’s test identifying publication bias. Trim-and-fill analysis methods were used for validation and sensitivity analysis. we also performed subgroup and meta-regression analyses.ResultsIn this study, we obtained 4,400 studies, 20 cross-sectional studies were screened and conducted a systematic review and meta-analysis. Results show: The overall prevalence of tuberculosis in deer in mainland China was 16.1% (95% confidence interval (CI):10.5 24.6; (Deer tuberculosis infected 5,367 out of 22,215 deer in mainland China) 5,367/22215; 1981 to 2023). The prevalence in Central China was the highest 17.5% (95% CI:14.0–21.9; 63/362), and among provinces, the prevalence in Heilongjiang was the highest at 26.5% (95% CI:13.2–53.0; 1557/4291). Elaphurus davidianus was the most commonly infected species, with a prevalence of 35.3% (95% CI:18.5–67.2; 6/17). We also assessed the association between geographic risk factors and the incidence of deer tuberculosis.ConclusionDeer tuberculosis is still present in some areas of China. Assessing the association between risk factors and the prevalence of deer tuberculosis showed that reasonable and scientific-based breeding methods, a suitable breeding environment, and rapid and accurate detection methods could effectively reduce the prevalence of deer tuberculosis. In addition, in the management and operation of the breeding base, improving the scientific feed nutrition standards and establishing comprehensive standards for disease prevention, immunization, quarantine, treatment, and disinfection according to the breeding varieties and scale, are suggested as ways to reduce the prevalence of deer tuberculosis

    Oocyte Source and Hormonal Stimulation for In Vitro

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    The aim of this study was to investigate the efficiency of in vitro embryo production in cattle utilizing sexed sperm from two bulls and oocytes recovered by OPU. Twenty donor animals were employed in eight OPU replicates: the first four OPU trials were conducted on animals without hormone treatment, and the last four were run on the same animals, following FSH subcutaneous and intramuscular administration. A higher rate of blastocyst development was recorded in stimulated, as compared to nonstimulated animals, (25.2% versus 12.8%, P = .001). Ocytes derived from slaughterhouse (SH) ovaries were also fertilized with sperm from the same bulls. Overall, non-sexed sperm used with oocytes derived from SH ovaries was significantly more efficient for blastocyst development than was sexed sperm with these same SH derived oocytes and sexed sperm with stimulated donor oocytes (39.8% versus 25.0% and 25.2%, P = .001). In conclusion, the use of sexed sperm with OPU-derived oocytes resulted in a significantly higher blastocyst development when donors were hormonally stimulated; furthermore, the level of efficiency achieved was comparable to that attained when the same sexed sperm was tested on oocytes derived from SH ovaries

    miR-184 Inhibits Tumor Invasion, Migration and Metastasis in Nasopharyngeal Carcinoma by Targeting Notch2

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    Background/Aims: A recent study found that dysregulated microRNA-184 (miR-184) is involved in the proliferation and survival of nasopharyngeal carcinoma (NPC). This study aimed to evaluate the detailed mechanisms of invasion, migration and metastasis of NPC cells. Methods: Quantitative reverse-transcription PCR (qRT-PCR) and Western blot were used to confirm the expression levels of miR-184 and Notch2. NPC cell invasion and migration were subsequently examined using in vitro cell invasion and wound-healing assays, respectively. MicroRNA (miRNA) target gene prediction databases and dual-luciferase reporter assay were adopted to validate the target genes of miR-184. Results: MiR-184 was downregulated in the NPC cell lines. The miR-184 inhibitor increased the number of invading NPC cells, whereas miR-184 mimics inhibited the invasive ability of such cells. The protein level of E-cadherin decreased, whereas those of N-cadherin and vimentin increased in the anti-miR-184 group. This result showed that miR-184 inhibited NPC cell invasion and metastasis by regulating EMT progression. MiRNA target gene prediction databases indicated the potential of Notch2 as a direct target gene of miR-184. Such a notion was then validated by results of dual-luciferase reporter assay. Notably, shRNANotch2 restrained the EMT and partially abrogated the inhibitory effects of miR-184 on EMT progression in NPC cells. Conclusion: MiR-184 functions as a tumour-suppressive miRNA targeting Notch2 and inhibits the invasion, migration and metastasis of NPC
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