| 1. |
- Akinsinde, Lewis O., et al.
(author)
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Surface characterization and resistance changes of silver-nanowire networks upon atmospheric plasma treatment
- 2021
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In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 550
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Journal article (peer-reviewed)abstract
- Highly conductive silver-nanowire (Ag-NW) networks are used in composite materials as conductive channels. Their resistance tuning can be accomplished by changing the Ag-NW concentration, and, therefore, changing the network structure. In this study, an alternative pathway to resistance engineering of conductive Ag-NW networks by local atmospheric plasma treatment is employed. The corresponding changes in nanowire network morphology and crystallinity as a function of plasma etching time are investigated by time-resolved grazingincidence X-ray scattering, field-effect scanning electron microscopy, and X-ray photoelectron spectroscopy. Three characteristic etching phases are identified. The first two phases enable the controlled engineering of the electrical properties with different rates of resistance change, which results from changes in nanowire shape, network morphology, and different oxidation rates. Phase III is characterized by pronounced fragmentation and destruction of the Ag-NW networks. These results show the feasibility of atmospheric plasma treatments to tune the local electrical properties of conductive Ag-NW networks. Furthermore, we present a physical Monte Carlo model explaining the electrical network properties as a function of plasma etching time based on the network connectivity and a constant plasma etching rate of 570 ng s-1 cm-2.
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| 4. |
- Jiang, Xiantao, et al.
(author)
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Two-dimensional MXenes : From morphological to optical, electric, and magnetic properties and applications
- 2020
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In: Physics reports. - : Elsevier. - 0370-1573 .- 1873-6270. ; 848
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Research review (peer-reviewed)abstract
- MXenes, generally referring to two-dimensional (2D) transition-metal carbides, nitrides, and carbonitrides, have received tremendous attention since the first report in 2011. Extensive experimental and theoretical studies have unveiled their enormous potential for applications in optoelectronics, photonics, catalysis, and many other areas. Because of their intriguing mechanical and electronic properties, together with the richness of elemental composition and chemical decoration, MXenes are poised to provide a new 2D nanoplatform for advanced optoelectronics. This comprehensive review, intended for a broad multidisciplinary readership, highlights the state-of-the-art progress on MXene theory, materials synthesis techniques, morphology modifications, opto-electromagnetic properties, and their applications. The efforts exploring the device performance limits, steric configurations, physical mechanisms, and novel application boundaries are comprehensively discussed. The review is concluded with a compelling perspective, outlook as well as non-trivial challenges in future investigation of MXene-based nano-optoelectronics.
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| 5. |
- Naydenov, M, et al.
(author)
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The Dynamics of miR-449a/c Expression during Uterine Cycles Are Associated with Endometrial Development
- 2023
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In: Biology. - : MDPI AG. - 2079-7737. ; 12:1
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Journal article (peer-reviewed)abstract
- The human endometrium is a highly dynamic tissue. Increasing evidence has shown that microRNAs (miRs) play essential roles in human endometrium development. Our previous assay, based on small RNA-sequencing (sRNA-seq) indicated the complexity and dynamics of numerous sequence variants of miRs (isomiRs) that can act together to control genes of functional relevance to the receptive endometrium (RE). Here, we used a greater average depth of sRNA-seq to detect poorly expressed small RNAs. The sequencing data confirmed the up-regulation of miR-449c and uncovered other members of the miR-449 family up-regulated in RE—among them miR-449a, as well as several isoforms of both miR-449a and miR-449c, while the third family member, miR-449b, was not identified. Stem-looped RT-qPCR analysis of miR expression at four-time points of the endometrial cycle verified the increased expression of the miR-449a/c family members in RE, among which the 5′ isoform of miR-449c–miR-449c.1 was the most strongly up-regulated. Moreover, we found in a case study that the expression of miR-449c.1 and its precursor correlated with the histological assessment of the endometrial phase and patient age. We believe this study will promote the clinical investigation and application of the miR-449 family in the diagnosis and prognosis of human reproductive diseases.
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| 6. |
- Nikolova, M, et al.
(author)
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Coupling miR/isomiR and mRNA Expression Signatures Unveils New Molecular Layers of Endometrial Receptivity
- 2021
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In: Life (Basel, Switzerland). - : MDPI AG. - 2075-1729. ; 11:12
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Journal article (peer-reviewed)abstract
- Embryo implantation depends on endometrial receptivity (ER). To achieve ER, the preparation of the uterine lining requires controlled priming by ovarian hormones and the expression of numerous genes in the endometrial tissue. microRNAs (miRs) have emerged as critical genetic regulators of ER in fertility and of the diseases that are associated with infertility. With the rapid development of next-generation sequencing technologies, it has become clear that miR genes can produce canonical miRs and variants—isomiRs. Here, we describe miR/isomiR expression dynamics across the four time points of natural chorionic gonadotropin (hCG)-administered cycles. Sequencing of the small RNAs (sRNA-seq) revealed that the most significant expression changes during the transition from the pre-receptive to the receptive phase occurred in the isomiR families of miR-125a, miR-125b, miR-10a, miR-10b, miR-449c, miR-92a, miR-92b, and miR-99a. Pairing the analysis of the differentially expressed (DE) miRs/isomiRs and their predicted DE mRNA targets uncovered 280 negatively correlating pairs. In the receptive endometrium, the 5′3′-isomiRs of miR-449c, which were among the most highly up-regulated isomiRs, showed a negative correlation with their target, transcription factor (TF) MYCN, which was down-regulated. Joint analysis of the miR/isomiR and TF expression identified several regulatory interactions. Based on these data, a regulatory TF-miR/isomiR gene-target circuit including let7g-5p and miR-345; the isomiR families of miR-10a, miR-10b, miR-92a, and miR-449c; and MYCN and TWIST1 was proposed to play a key role in the establishment of ER. Our work uncovers the complexity and dynamics of the endometrial isomiRs that can act cooperatively with miRs to control the functionally important genes that are critical to ER. Further studies of miR/isomiR expression patterns that are paired with those of their target mRNAs may provide a more in-depth picture of the endometrial pathologies that are associated with implantation failure.
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| 7. |
- Reddy, I. V. A. K., et al.
(author)
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Pulsed response theory prediction of ZnO nanocluster polarizabilities : A benchmark study
- 2021
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In: Chemical Physics Letters. - : Elsevier. - 0009-2614 .- 1873-4448. ; 778
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Journal article (peer-reviewed)abstract
- Motivated by the interest in zinc oxide nanostructures and their properties, we calculate in this work molecular polarizabilities and hyperpolarizabilities of a series of zinc oxide nanoclusters using modern response theory in the form of damped and pulsed response for both Hartree-Fock and DFT reference states. We show that as the size of the cluster grows, both real and imaginary parts of polarizability, computed with these two distinct approaches, asymptotically converge. We also show the importance of eliminating the dangling bonds in small clusters for predicting the correct trend in the values of the HOMO/LUMO gap. Finally, we calculate the hyperpolarizability tensors, associated with the second order nonlinear optical effects, in the hexagonal (wurtzite) phase of ZnO nanoclusters and demonstrate a highly nonlinear growth of this quantity with the cluster size.
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