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During typical microRNA (miRNA) biogenesis, one strand of a approximately 22 nt RNA duplex is preferentially selected for entry into a silencing complex, whereas the other strand, known as the passenger strand or miRNA* strand, is degraded. Recently, some miRNA* sequences were reported as guide miRNAs with abundant expression. Here, we intended to discover evolutionary implication of the fate of miRNA* strand by analyzing miRNA/miRNA* sequences across vertebrates. Mature miRNAs based on gene families were well conserved especially for their seed sequences across vertebrates, while their passenger strands always showed various divergence patterns. The divergence mainly resulted from divergence of different animal species, homologous miRNA genes and multicopy miRNA hairpin precursors. Some miRNA* sequences were phylogenetically conserved in seed and anchor sequences similar to mature miRNAs, while others revealed high levels of nucleotide divergence despite some of their partners were highly conserved. Most of those miRNA precursors that could generate abundant miRNAs from both strands always were well conserved in sequences of miR-#-5p and miR-#-3p, especially for their seed sequences. The final fate of miRNA* strand, either degraded as merely carrier strand or expressed abundantly as potential functional guide miRNA, may be destined across evolution. Well-conserved miRNA* strands, particularly conservation in seed sequences, maybe afford potential opportunities for contributing to regulation network. The study will broaden our understanding of potential functional miRNA* species. Source


Qin Y.L.,Nanjing Southeast University
JACC. Cardiovascular interventions | Year: 2013

This study sought to evaluate the early and long-term effect of thoracic endovascular aortic repair (TEVAR) on type-B acute aortic dissection (AAD). Uncomplicated type-B AAD is generally treated with medical management; complicated dissections require surgery or TEVAR. Studies have demonstrated that long-term outcomes with medical management are suboptimal. Therefore, we sought to determine the long-term effect of TEVAR compared with medical management alone on type-B AAD. From January 2004 to May 2008, 193 consecutive patients in 2 hospitals were treated and retrospectively placed into 1 of 2 groups: 1) the TEVAR group-type-B AAD treated with TEVAR and antihypertensive medications (n = 152); and the 2) medicine group-uncomplicated type-B AAD treated medically alone (n = 41). All TEVAR procedures were performed in the acute phase. There were no significant differences in demographics, comorbidity profiles, or early events between groups. The cumulative freedom from all late adverse events at 1, 3, and 5 years was 97%, 89%, and 67% in the TEVAR group and 97%, 63%, and 34% in the medicine group. Log-rank tests showed that medically treated patients had more late adverse events than TEVAR-treated patients did (p = 0.003). The 5-year cumulative survival rate from all-cause death was not significantly different between the 2 groups. Patients with type-B AAD treated with TEVAR experienced fewer late adverse events than those treated with medical management, but there was no significant difference among the groups in 5-year mortality rates. Further studies of longer-term survival rates are needed to determine whether TEVAR could be an effective treatment for type-B AAD. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved. Source


Yang W.-X.,Nanjing Southeast University
Optics Letters | Year: 2015

We investigate the high-order harmonic generation (HHG) in a semiconductor quantum dot (SQD) and metallic nanorod (MNR) complex driven by a moderate intensity (<1012 W/cm2) frequency-chirped Gaussian few-cycle pulse. Our numerical results indicate that the cutoff energy of the HHG can be controlled by optimizing the shape of the MNR and surface-to-surface distance between the SQD and the MNR. We also show that the extreme ultraviolet supercontinuum harmonics (25 eV maximal photon energy) and isolated ultrashort pulses (2.67-4.36 fs FWHM) are achievable. © 2015 Optical Society of America. Source


Hou J.-M.,Nanjing Southeast University
Physical Review Letters | Year: 2013

We study a two-dimensional fermionic square lattice, which supports the existence of a two-dimensional Weyl semimetal, quantum anomalous Hall effect, and 2π-flux topological semimetal in different parameter ranges. We show that the band degenerate points of the two-dimensional Weyl semimetal and 2π-flux topological semimetal are protected by two distinct novel hidden symmetries, which both correspond to antiunitary composite operations. When these hidden symmetries are broken, a gap opens between the conduction and valence bands, turning the system into a insulator. With appropriate parameters, a quantum anomalous Hall effect emerges. The degenerate point at the boundary between the quantum anomalous Hall insulator and trivial band insulator is also protected by the hidden symmetry. © 2013 American Physical Society. Source


Ma H.F.,Nanjing Southeast University
Nature communications | Year: 2010

Since invisibility cloaks were first suggested by transformation optics theory, there has been much work on the theoretical analysis and design of various types and a few experimental verifications at microwave and optical frequencies within two-dimensional limits. Here, we realize the first practical implementation of a fully 3D broadband and low-loss ground-plane cloak at microwave frequencies. The cloak, realized by drilling inhomogeneous holes in multi-layered dielectric plates, can conceal a 3D object located under a curved conducting plane from all viewing angles by imitating the reflection of a flat conducting plane. We also designed and realized, using non-resonant metamaterials, a high-gain lens antenna that can produce narrow-beam plane waves in the near-field region in a broad frequency band. The antenna constitutes the transmitter of the measurement system and is essential for the measurement of cloaking behaviour. Source

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