Efficient Initialization of Fluxonium Qubits based on Auxiliary Energy Levels.

Fast and high-fidelity qubit initialization is crucial for low-frequency qubits such as fluxonium, and in applications of many quantum algorithms and quantum error correction codes. In a circuit quantum electrodynamics system, the initialization is typically achieved by transferring the state between the qubit and a short-lived cavity through microwave driving, also known as the sideband cooling process in atomic system. Constrained by the selection rules from the parity symmetry of the wave functions, the sideband transitions are only enabled by multiphoton processes which require multitone or strong driving. Leveraging the flux tunability of fluxonium, we circumvent this limitation by breaking flux symmetry to enable an interaction between a noncomputational qubit transition and the cavity excitation. With single-tone sideband driving, we realize qubit initialization with a fidelity exceeding 99% within a duration of 300 ns, robust against the variation of control parameters. Furthermore, we show that our initialization scheme has a built-in benefit in simultaneously removing the second-excited state population of the qubit, and can be easily incorporated into a large-scale fluxonium processor.

Native Approach to Controlled-Z Gates in Inductively Coupled Fluxonium Qubits.

The fluxonium qubits have emerged as a promising platform for gate-based quantum information processing. However, their extraordinary protection against charge fluctuations comes at a cost: when coupled capacitively, the qubit-qubit interactions are restricted to XX interactions. Consequently, effective ZZ or XZ interactions are only constructed either by temporarily populating higher-energy states, or by exploiting perturbative effects under microwave driving. Instead, we propose and demonstrate an inductive coupling scheme, which offers a wide selection of native qubit-qubit interactions for fluxonium. In particular, we leverage a built-in, flux-controlled ZZ interaction to perform qubit entanglement. To combat the increased flux-noise-induced dephasing away from the flux-insensitive position, we use a continuous version of the dynamical decoupling scheme to perform noise filtering. Combining these, we demonstrate a 20 ns controlled-z gate with a mean fidelity of 99.53%. More than confirming the efficacy of our gate scheme, this high-fidelity result also reveals a promising but rarely explored parameter space uniquely suitable for gate operations between fluxonium qubits.

LncRNA GAS5 regulated by FTO-mediated m6A demethylation promotes autophagic cell death in NSCLC by targeting UPF1/BRD4 axis.

Long non-coding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) has been shown to be a regulator for many cancers, including non-small cell lung cancer (NSCLC). Therefore, its role and mechanism in the process of NSCLC deserve to be further revealed. The expression levels of GAS5, fat mass and obesity-associated protein (FTO) and bromodomain-containing protein 4 (BRD4) were detected by quantitative real-time PCR. Western blot analysis was used to examine the protein expression of FTO, BRD4, up-frameshift protein 1 (UPF1) and autophagy-related markers. Methylated RNA immunoprecipitation was used to assess the m6A level of GAS5 regulated by FTO. Cell proliferation and apoptosis were determined using MTT assay, EdU assay and flow cytometry. Autophagy ability was assessed by immunofluorescence staining and transmission electron microscope. Xenograft tumor model was constructed to explore the effects of FTO and GAS5 on NSCLC tumor growth in vivo. The interaction between UPF1 and GAS5 or BRD4 was confirmed by pull-down assay, RIP assay, dual-luciferase reporter assay, and chromatin immunoprecipitation. Fluorescent in situ hybridization was used to analyze the co-localization of GAS5 and UPF1. Actinomycin D treatment was employed to evaluate BRD4 mRNA stability. GAS5 was downregulated in NSCLC tissues and was associated with poor prognosis in NSCLC patients. FTO was highly expressed in NSCLC, and it inhibited GAS5 expression by reducing GAS5 m6A methylation level. GAS5 suppressed by FTO could promote the autophagic death of NSCLC cells in vitro and inhibit NSCLC tumor growth in vivo. In addition, GAS5 was able to interact with UPF1 to reduce the mRNA stability of BRD4. Knockdown of BRD4 reversed the inhibition of GAS5 or UPF1 silencing on the autophagic cell death of NSCLC. The findings of the study showed that lncRNA GAS5 mediated by FTO could contribute to the autophagic cell death of NSCLC by interacting with UPF1 to reduce BRD4 mRNA stability, suggesting that GAS5 might be a vital therapy target for NSCLC progression.

LncRNA GAS5 expression in non-small cell lung cancer tissues and its correlation with Ki67 and EGFR.

OBJECTIVE: This research explored and analyzed LncRNA GAS5 expression in non-small cell lung cancer (NSCLC) tissues and its correlation with Ki67 and EGFR. METHODS: A total of 130 samples of paraffin-embedded NSCLC tissues and para-cancerous normal tissues that were collected in the Department of Pathology from January 2014 to April 2016 were selected. The relative expression of LncRNA GAS5 and Ki67/EGFR in both NSCLC tissues and para-cancerous normal tissues were detected via RT-PCR and immunohistochemistry respectively. Subsequently, we analyzed the relative expression of LncRNA GAS5, the expression of Ki67/EGFR and its correlation with clinicopathological features and prognosis of patients, and studied the correlation between LncRNA GAS5 and Ki67/EGFR. RESULTS: The relative expression of LncRNA GAS5 in NSCLC tissues was substantially less than that of the para-cancerous normal tissues (P<0.05). The positive expression rate of Ki67/EGFR in NSCLC tissues remarkably exceeded that in para-cancerous normal tissues (P<0.05). The relative expression of LncRNA GAS5 was correlated with the degree of tumor differentiation, TNM staging and lymph node metastasis (P<0.05). The positive expression rate of Ki67 and EGFR in NSCLC tissues was related to TNM stage and metastasis of lymph node (P<0.05). In addition, the survival of patients with high LncRNA GAS5 expression was obviously superior to those with low LncRNA GAS5 expression (P<0.05), patients with negative Ki67 had superior survival than those with positive Ki67 (P<0.05), and patients with negative EGFR had increased survival over those with positive EGFR (P<0.05). Moreover, the positive rates of Ki67 and EGFR in patients with low LncRNA GAS5 expressions were obviously higher than those with high LncRNA GAS5 expressions (P<0.05). The relative expression level of LncRNA GAS5 in NSCLC patients had a remarkably negative correlation with Ki67 and EGFR (P<0.05). CONCLUSION: The decrease in LncRNA GAS5 expression and the over-express of Ki67/EGFR occur in NSCLC tissues, the expressions of LncRNA GAS5, Ki67 and EGFR are connected with the progression, metastasis and prognosis of tumor; and LncRNA GAS5 is related to the expression of Ki67 and EGFR. These three factors are involved in the tumorigenesis and growth of the NSCLC process.

YAP1 expression in nasal polyps and its relationship with epithelial mesenchymal transition.

OBJECTIVE: This study explored and analyzed the expression of YAP1 in nasal polyps and its correlation with the epithelial-mesenchymal transition (EMT). METHOD: 58 patients with chronic sinusitis and nasal polyps, who were hospitalized in the otorhinolaryngology department of our hospital from January 2019 to May 2020 were recruited as the study cohort and placed in a nasal-polyp group, and, at the same time, another 30 nasal septum deviation with inferior turbinate hypertrophy patients were placed in a control group. The expressions of the YAP1 gene in the nasal polyp and turbinate mucosa tissues (using the immunohistochemical method), the YAP1 mRNA, E-cadherin mRNA, and vimentin mRNA expressions (using the RT-PCR method), and the YAP1, E-cadherin, and vimentin protein expressions (using Western blot) were measured, and the correlations between YAP1 and the expressions of E-cadherin and vimentin were analyzed. RESULTS: The immunohistochemistry results revealed that the positive rate of YAP1 expression in the nasal-polyps group was critically higher than the YAP1 expression in the control group (P<0.05). According to the RT-PCR results, the YAP1 mRNA and vimentin mRNA relative expression levels in the nasal-polyps group were significantly higher than they were in the control group (P<0.05), but the E-cadherin mRNA relative expression level in the nasal-polyp group was notably lower than it was in the control group (P<0.05). Our Western blot analysis showed that the protein expressions of YAP1 and vimentin protein in the nasal-polyps group were significantly higher than the corresponding protein expressions in the control group (P<0.05), but the E-cadherin expression in the nasal-polyp group was especially lower than it was in the control group (P<0.05). In addition, in the nasal polyp tissues, the relative expression between the YAP1 mRNA and the E-cadherin mRNA reflected a notably negative correlation (P<0.05), but the YAP1 mRNA and vimentin mRNA showed a positive correlation (P<0.05). CONCLUSION: High expressions of YAP1 and EMT occur in nasal polyp tissues, and YAP1 is likely to be involved in the regulation of EMT and might be one of the mechanisms in nasal polyps.

Self-Assembly Anisotropic Magnetic Nanowire Films Induced by External Magnetic Field.

Self-assembly generated materials induced by an external magnetic field have attracted considerable interest following the development of nanodevices. However, the fabrication of macroscopic and anisotropic magnetic films at the nanoscale remains a challenge. Here, anisotropic magnetic films are successfully prepared using a solution-based nanowire assembly strategy under a magnetic field. The assembly process is manipulated by changing the thickness of silica shell coated on the surface of magnetic nanowires. The anisotropic magnetic films show highly anisotropic magnetization under different angles of magnetic field and better magnetization properties than that of disordered magnetic films. The well-defined nanowire arrays enable magnetization anisotropic property which may be useful in the magnetic energy conversion technologies and biomedical sciences which lie far beyond those achievable with traditional magnetic materials.