Metalenses consist of an array of optical nanoantennas on a surface capable of manipulating the properties of an incoming light wavefront. Various flat optical components, such as polarizers, optical ...imaging encoders, tunable phase modulators and a retroreflector, have been demonstrated using a metalens design. An open issue, especially problematic for colour imaging and display applications, is the correction of chromatic aberration, an intrinsic effect originating from the specific resonance and limited working bandwidth of each nanoantenna. As a result, no metalens has demonstrated full-colour imaging in the visible wavelength. Here, we show a design and fabrication that consists of GaN-based integrated-resonant unit elements to achieve an achromatic metalens operating in the entire visible region in transmission mode. The focal length of our metalenses remains unchanged as the incident wavelength is varied from 400 to 660 nm, demonstrating complete elimination of chromatic aberration at about 49% bandwidth of the central working wavelength. The average efficiency of a metalens with a numerical aperture of 0.106 is about 40% over the whole visible spectrum. We also show some examples of full-colour imaging based on this design.
Among various flat optical devices, metasurfaces have presented their great ability in efficient manipulation of light fields and have been proposed for variety of devices with specific ...functionalities. However, due to the high phase dispersion of their building blocks, metasurfaces significantly suffer from large chromatic aberration. Here we propose a design principle to realize achromatic metasurface devices which successfully eliminate the chromatic aberration over a continuous wavelength region from 1200 to 1680 nm for circularly-polarized incidences in a reflection scheme. For this proof-of-concept, we demonstrate broadband achromatic metalenses (with the efficiency on the order of ∼12%) which are capable of focusing light with arbitrary wavelength at the same focal plane. A broadband achromatic gradient metasurface is also implemented, which is able to deflect wide-band light by the same angle. Through this approach, various flat achromatic devices that were previously impossible can be realized, which will allow innovation in full-color detection and imaging.Metasurfaces suffer from large chromatic aberration due to the high phase dispersion of their building blocks, limiting their applications. Here, Wang et al. design achromatic metasurface devices which eliminate the chromatic aberration over a continuous region from 1200 to 1680 nm in a reflection schleme.
To investigate the effectiveness of a school-based program promoting outdoor activities in Taiwan for myopia prevention and to identify protective light intensities.
Multi-area, cluster-randomized ...intervention controlled trial.
A total 693 grade 1 schoolchildren in 16 schools participated. Two hundred sixty-seven schoolchildren were in the intervention group and 426 were in the control group.
Initially, 24 schools were randomized into the intervention and control groups, but 5 and 3 schools in the intervention and control groups, respectively, withdrew before enrollment. A school-based Recess Outside Classroom Trial was implemented in the intervention group, in which schoolchildren were encouraged to go outdoors for up to 11 hours weekly. Data collection included eye examinations, cycloplegic refraction, noncontact axial length measurements, light meter recorders, diary logs, and questionnaires.
Change in spherical equivalent and axial length after 1 year and the intensity and duration of outdoor light exposures.
The intervention group showed significantly less myopic shift and axial elongation compared with the control group (0.35 diopter D vs. 0.47 D; 0.28 vs. 0.33 mm; P = 0.002 and P = 0.003) and a 54% lower risk of rapid myopia progression (odds ratio, 0.46; 95% confidence interval CI, 0.28-0.77; P = 0.003). The myopic protective effects were significant in both nonmyopic and myopic children compared with controls. Regarding spending outdoor time of at least 11 hours weekly with exposure to 1000 lux or more of light, the intervention group had significantly more participants compared with the control group (49.79% vs. 22.73%; P < 0.001). Schoolchildren with longer outdoor time in school (≥200 minutes) showed significantly less myopic shift (measured by light meters; ≥1000 lux: 0.14 D; 95% CI, 0.02-0.27; P = 0.02; ≥3000 lux: 0.16 D; 95% CI, 0.002-0.32; P = 0.048).
The school-based outdoor promotion program effectively reduced the myopia change in both nonmyopic and myopic children. Outdoor activities with strong sunlight exposure may not be necessary for myopia prevention. Relatively lower outdoor light intensity activity with longer time outdoors, such as in hallways or under trees, also can be considered.
Metasurface-based components are known to be one of the promising candidates for developing flat optical systems. However, their low working efficiency highly limits the use of such flat components ...for feasible applications. Although the introduction of the metallic mirror has been demonstrated to successfully enhance the efficiency, it is still somehow limited for imaging and sensing applications because they are only available for devices operating in a reflection fashion. Here, we demonstrate three individual GaN-based metalenses working in a transmission window with extremely high operation efficiency at visible light (87%, 91.6%, and 50.6% for blue, green, and red light, respectively). For the proof of concept, a multiplex color router with dielectric metalens, which is capable of guiding individual primary colors into different spatial positions, is experimentally verified based on the design of out-of-plane focusing metalens. Our approach with low-cost, semiconductor fabrication compatibility and high working efficiency characteristics offers a way for establishing a complete set of flat optical components for a wide range of applications such as compact imaging sensors, optical spectroscopy, and high-resolution lithography, just named a few.
Introgressive hybridization is now recognized as a widespread phenomenon, but its role in evolution remains contested. Here, we use newly available reference genome assemblies to investigate ...phylogenetic relationships and introgression in a medically important group of Afrotropical mosquito sibling species. We have identified the correct species branching order to resolve a contentious phylogeny and show that lineages leading to the principal vectors of human malaria were among the first to split. Pervasive autosomal introgression between these malaria vectors means that only a small fraction of the genome, mainly on the X chromosome, has not crossed species boundaries. Our results suggest that traits enhancing vectorial capacity may be gained through interspecific gene flow, including between nonsister species. Mosquito adaptability across genomesVirtually everyone has first-hand experience with mosquitoes. Few recognize the subtle biological distinctions among these bloodsucking flies that render some bites mere nuisances and others the initiation of a potentially life-threatening infection. By sequencing the genomes of several mosquitoes in depth, Neafsey et al. and Fontaine et al. reveal clues that explain the mystery of why only some species of one genus of mosquitoes are capable of transmitting human malaria (see the Perspective by Clark and Messer).Science, this issue 10.1126/science.1258524 and 10.1126/science.1258522; see also p. 27
Ultrathin Planar Cavity Metasurfaces Wang, Hsiang‐Chu; Chu, Cheng Hung; Wu, Pin Chieh ...
Small (Weinheim an der Bergstrasse, Germany)
14, Številka:
17
Journal Article
Recenzirano
An ultrathin planar cavity metasurface is proposed based on ultrathin film interference and its practicability for light manipulation in visible region is experimentally demonstrated. Phase of ...reflected light is modulated by finely adjusting the thickness of amorphous silicon (a‐Si) by a few nanometers on an aluminum (Al) substrate via nontrivial phase shifts at the interfaces and interference of multireflections generated from the planar cavity. A phase shift of π, the basic requirement for two‐level phase metasurface systems, can be accomplished with an 8 nm thick difference. For proof of concept, gradient metasurfaces for beam deflection, Fresnel zone plate metalens for light focusing, and metaholograms for image reconstruction are presented, demonstrating polarization‐independent and broadband characteristics. This novel mechanism for phase modulation with ultrathin planar cavity provides diverse routes to construct advanced flat optical devices with versatile applications.
An ultrathin planar cavity metasurface based on ultrathin film interference is reported. A phase shift of π can be accomplished with an 8 nm thick difference of amorphous silicon. For proof of concept, gradient metasurfaces for beam deflection, Fresnel zone plate metalens for light focusing, and metaholograms for image reconstruction are demonstrated in the visible spectrum.
Abstract
Summary
We describe eMPRess, a software program for phylogenetic tree reconciliation under the duplication-transfer-loss model that systematically addresses the problems of choosing event ...costs and selecting representative solutions, enabling users to make more robust inferences.
Availability and implementation
eMPRess is freely available at http://www.cs.hmc.edu/empress.
Supplementary information
Supplementary data are available at Bioinformatics online.
IL‐20 is a proinflammatory cytokine of the IL‐10 family and involved in several diseases. However, the regulatory role of IL‐20 in obesity is not well understood. We explored the function of IL‐20 in ...the pathogenesis of obesity‐induced insulin resistance by ELISA, Western blotting and flow cytometry. The therapeutic potential of IL‐20 monoclonal antibody 7E for ameliorating diet‐induced obesity was analysed in murine models. Higher serum IL‐20 levels were detected in obese patients. It was upregulated in leptin‐deficient (ob/ob), leptin‐resistant (db/db) and high‐fat diet (HFD)‐induced murine obesity models. In vitro, IL‐20 regulated the adipocyte differentiation and the polarization of bone marrow‐derived macrophages into proinflammatory M1 type. It also caused inflammation and macrophage retention in adipose tissues by upregulating TNF‐α, monocyte chemotactic protein 1 (MCP‐1), netrin 1 and unc5b (netrin receptor) expression in macrophages and netrin 1, leptin and MCP‐1 in adipocytes. IL‐20 promoted insulin resistance by inhibiting glucose uptake in mature adipocytes through the SOCS‐3 pathway. In HFD‐induced obesity in mice, 7E treatment reduced body weight and improved glucose tolerance and insulin sensitivity; it also reduced local inflammation and the number of M1‐like macrophages in adipose tissues. We have identified a critical role of IL‐20 in obesity‐induced inflammation and insulin resistance, and we conclude that IL‐20 may be a novel target for treating obesity and insulin resistance in patients with metabolic disorders.
IL‐20 acts as an important regulator in obesity‐related adipose tissue inflammation and insulin resistance by regulating adipocyte differentiation and affecting macrophage recruitment and polarization.
γδ T cells are a distinct subgroup of T cells that bridge the innate and adaptive immune system and can attack cancer cells in an MHC-unrestricted manner. Trials of adoptive γδ T cell transfer in ...solid tumors have had limited success. Here, we show that DNA methyltransferase inhibitors (DNMTis) upregulate surface molecules on cancer cells related to γδ T cell activation using quantitative surface proteomics. DNMTi treatment of human lung cancer potentiates tumor lysis by ex vivo-expanded Vδ1-enriched γδ T cells. Mechanistically, DNMTi enhances immune synapse formation and mediates cytoskeletal reorganization via coordinated alterations of DNA methylation and chromatin accessibility. Genetic depletion of adhesion molecules or pharmacological inhibition of actin polymerization abolishes the potentiating effect of DNMTi. Clinically, the DNMTi-associated cytoskeleton signature stratifies lung cancer patients prognostically. These results support a combinatorial strategy of DNMTis and γδ T cell-based immunotherapy in lung cancer management.
PDF
