DNA nanotechnology-enabled chiral plasmonics: from static to dynamic

In this Account, we discuss a variety of static and dynamic chiral plasmonic nanostructures enabled by DNA nanotechnology. In the category of static plasmonic systems, we first show chiral plasmonic nanostructures based on spherical AuNPs, including plasmonic helices, toroids, and tetramers. To enhance the CD responses, anisotropic gold nanorods with larger extinction coefficients are utilized to create chiral plasmonic crosses and helical superstructures. Next, we highlight the inevitable evolution from static to dynamic plasmonic systems along with the fast development of this interdisciplinary field. Several dynamic plasmonic systems are reviewed according to their working mechanisms.Comment: 7 figure

Offshoring Pollution while Offshoring Production?

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138846/1/smj2656.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138846/2/smj2656_am.pd

Subsidiary divestiture and acquisition in a financial crisis: Operational focus, financial constraints, and ownership

We exploit parent- and subsidiary-level data for publicly listed firms in Thailand before, during, and after the 1997 Asian Financial Crisis to investigate the extent to which firms with different types of ownership restructure their business portfolios, in terms of divestitures and acquisitions. We compare restructuring choices made by firms mostly owned by (a) domestic individuals with block shares (family firms), (b) domestic firms and/or institutions (DI firms), and (c) foreign investors (foreign firms). We show that following the crisis (1) foreign firms' restructuring behavior is the least affected; (2) domestic firms owned by families and domestic institutions (DI) behave similarly to one another; (3) domestic firms do not increase divestiture in their peripheral segments to improve operational focus or to obtain cash in a credit crunch; they actually reduce divestiture in core segments; and (4) domestic firms also significantly reduce the acquisition of new subsidiaries. Our results challenge traditional explanations for divestiture such as corporate governance, operational refocus, and financial constraints. They indicate that in the great uncertainty of a crisis, domestic firms are able to hold onto their core assets to avoid fire-sale. In essence, they act more conservatively in churning their business portfolios

Light Field Depth Estimation Based on Stitched-EPI

Depth estimation is one of the most essential problems for light field applications. In EPI-based methods, the slope computation usually suffers low accuracy due to the discretization error and low angular resolution. In addition, recent methods work well in most regions but often struggle with blurry edges over occluded regions and ambiguity over texture-less regions. To address these challenging issues, we first propose the stitched-EPI and half-stitched-EPI algorithms for non-occluded and occluded regions, respectively. The algorithms improve slope computation by shifting and concatenating lines in different EPIs but related to the same point in 3D scene, while the half-stitched-EPI only uses non-occluded part of lines. Combined with the joint photo-consistency cost proposed by us, the more accurate and robust depth map can be obtained in both occluded and non-occluded regions. Furthermore, to improve the depth estimation in texture-less regions, we propose a depth propagation strategy that determines their depth from the edge to interior, from accurate regions to coarse regions. Experimental and ablation results demonstrate that the proposed method achieves accurate and robust depth maps in all regions effectively.Comment: 15 page

Recent Advances in Ambipolar Transistors for Functional Applications

Ambipolar transistors represent a class of transistors where positive (holes) and negative (electrons) charge carriers both can transport concurrently within the semiconducting channel. The basic switching states of ambipolar transistors are comprised of common offâ state and separated onâ state mainly impelled by holes or electrons. During the past years, diverse materials are synthesized and utilized for implementing ambipolar charge transport and their further emerging applications comprising ambipolar memory, synaptic, logic, and lightâ emitting transistors on account of their special bidirectional carrierâ transporting characteristic. Within this review, recent developments of ambipolar transistor field involving fundamental principles, interface modifications, selected semiconducting material systems, device structures, ambipolar characteristics, and promising applications are highlighted. The existed challenges and prospective for researching ambipolar transistors in electronics and optoelectronics are also discussed. It is expected that the review and outlook are well timed and instrumental for the rapid progress of academic sector of ambipolar transistors in lighting, display, memory, as well as neuromorphic computing for artificial intelligence.Ambipolar transistors represent transistors that allow synchronous transport of electrons and holes and their accumulation within semiconductors. This review provides a comprehensive summary of recent advances in various semiconducting materials realized in ambipolar transistors and their functional memory, synapse, logic, as well as lightâ emitting applications.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151885/1/adfm201902105_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151885/2/adfm201902105.pd

Salt Compartmentation and Antioxidant Defense in Roots and Leaves of Two Non-Salt Secretor Mangroves under Salt Stress

The effects of increasing NaCl (100–400 mM) on cellular salt distribution, antioxidant enzymes, and the relevance to reactive oxygen species (ROS) homeostasis were investigated in 1-year-old seedlings of two non-salt secretor mangroves, Kandelia obovata and Bruguiera gymnorhiza. K. obovata accumulated less Na+ and Cl− in root cells and leaf compartments under 400 mM NaCl compared to B. gymnorhiza. However, B. gymnorhiza leaves are notable for preferential accumulation of salt ions in epidermal vacuoles relative to mesophyll vacuoles. Both mangroves upregulated antioxidant enzymes in ASC-GSH cycle to scavenge the salt-elicited ROS in roots and leaves but with different patterns. K. obovata rapidly initiated antioxidant defense to reduce ROS at an early stage of salt stress, whereas B. gymnorhiza maintained a high capacity to detoxify ROS at high saline. Collectively, our results suggest that salinized plants of the two mangroves maintained ROS homeostasis through (i) ROS scavenging by antioxidant enzymes and (ii) limiting ROS production by protective salt compartmentation. In the latter case, an efficient salt exclusion is favorable for K. obovata to reduce the formation of ROS in roots and leaves, while the effective vacuolar salt compartmentation benefited B. gymnorhiza leaves to avoid excessive ROS production in a longer term of increasing salinity