884 research outputs found
Integrated all-optical logic discriminators based on plasmonic bandgap engineering
Optical computing uses photons as information carriers, opening up the
possibility for ultrahigh-speed and ultrawide-band information processing.
Integrated all-optical logic devices are indispensible core components of
optical computing systems. However, up to now, little experimental progress has
been made in nanoscale all-optical logic discriminators, which have the
function of discriminating and encoding incident light signals according to
wavelength. Here, we report a strategy to realize a nanoscale all-optical logic
discriminator based on plasmonic bandgap engineering in a planar plasmonic
microstructure. Light signals falling within different operating wavelength
ranges are differentiated and endowed with different logic state encodings.
Compared with values previously reported, the operating bandwidth is enlarged
by one order of magnitude. Also the SPP light source is integrated with the
logic device while retaining its ultracompact size. This opens up a way to
construct on-chip all-optical information processors and artificial
intelligence systems.Comment: 4 figures 201
Ultrawide-band Unidirectional Surface Plasmon Polariton Launchers
Plasmonic devices and circuits, bridging the gap between integrated photonic
and microelectronic technology, are promising candidates to realize on-chip
ultrawide-band and ultrahigh-speed information processing. Unfortunately, the
wideband surface plasmon source, one of the most important core components of
integrated plasmonic circuits, is still unavailable up to now. This has
seriously restricted the practical applications of plasmonic circuits. Here, we
report an ultrawide-band unidirectional surface plasmon polariton launcher with
high launching efficiency ratio and large extinction ratio, realized by
combining plasmonic bandgap engineering and linear interference effect. This
device offers excellent performances over an ultrabroad wavelength range from
690 to 900 nm, together with a high average launching efficiency ratio of 1.25,
large average extinction ratio of 30 dB, and ultracompact lateral dimension of
less than 4 um. Compared with previous reports, the operating bandwidth is
enlarged 210 folds, while the largest launching efficiency ratio, largest
extinction ratio, and small feature size are maintained simultaneously. This
provides a strategy for constructing on-chip surface plasmon source, and also
paving the way for the study of integrated plasmonic circuits.Comment: 4 figure
A Retrospective on Nuclear Receptor Regulation of Inflammation: Lessons from GR and PPARs
Members of the nuclear receptor superfamily have vital roles in regulating immunity and inflammation. The founding member, glucocorticoid receptor (GR), is the prototype to demonstrate immunomodulation via transrepression of the AP-1 and NF-κB signaling pathways. Peroxisome proliferator-activated receptors (PPARs) have emerged as key regulators of inflammation. This review examines the history and current advances in nuclear receptor regulation of inflammation by the crosstalk with AP-1 and NF-κB signaling, focusing on the roles of GR and PPARs. A better understanding of the molecular mechanism by which nuclear receptors inhibit proinflammatory signaling pathways will enable novel therapies to treat chronic inflammation
O-GlcNAc as an Integrator of Signaling Pathways
O-GlcNAcylation is an important posttranslational modification governed by a single pair of enzymes–O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). These two enzymes mediate the dynamic cycling of O-GlcNAcylation on a wide variety of cytosolic, nuclear and mitochondrial proteins in a nutrient- and stress-responsive fashion. While cellular functions of O-GlcNAcylation have been emerging, little is known regarding the precise mechanisms how the enzyme pair senses the environmental cues to elicit molecular and physiological changes. In this review, we discuss how the OGT/OGA pair acts as a metabolic sensor that integrates signaling pathways, given their capability of receiving signaling inputs from various partners, targeting multiple substrates with spatiotemporal specificity and translocating to different parts of the cell. We also discuss how the pair maintains homeostatic signaling within the cell and its physiological relevance. A better understanding of the mechanisms of OGT/OGA action would enable us to derive therapeutic benefits of resetting cellular O-GlcNAc levels within an optimal range
Toward Collinearity-Avoidable Localization for Wireless Sensor Network
In accordance with the collinearity problem during computation caused by the beacon nodes used for location estimation which are close to be in the same line or same plane, two solutions are proposed in this paper: the geometric analytical localization algorithm based on positioning units and the localization algorithm based on the multivariate analysis method. The geometric analytical localization algorithm based on positioning units analyzes the topology quality of positioning units used to estimate location and provides quantitative criteria based on that; the localization algorithm based on the multivariate analysis method uses the multivariate analysis method to filter and integrate the beacon nodes coordinate matrixes during the process of location estimation. Both methods can avoid low estimation accuracy and instability caused by multicollinearity
Research on the influence of virtual modeling and testing–based rubber track system on vibration performance of engineering vehicles
The rubbertrack system can be quickly swapped on the tyres, exerting a smaller ground pressure while generating a greater adhesion to solve the problem vehicles faced in traversing rough and difficult terrain. This paper will discuss the influence of rubber track system on the ride comfort of engineering vehicles with rigid suspension. First, a multi-body dynamic model of the rubber track system and a mathematical model of contact between the ground and the track are established, and then the macro commands are programmed to add many complex contact forces. Moreover, by using the method of physical prototype obstacle testing, the correctness of the simulation model is validated. The ride comfort of the engineering vehicle when equipped with rubber track system is explored by the method of the multi-body dynamics and real vehicle test. The research shows that a flexible roller wheel system can significantly improve the ride comfort of the engineering vehicle when compared to wheeled vehicles. When the vehicle speed is low, the weighted root-meansquare acceleration of the wheeled vehicle and tracked vehicle is almost the same. At the same time, it is verified that the ride comfort of the steelchain tracked vehicles is worse than that of rubber tracked vehicles, due to the polygon effect. Through the multi-body dynamics simulation of the virtual prototype, we can predict and evaluate the ride comfort of vehicles, saving the cost of testing and obtaining the actual experimental data, which has great significance for the research and development of vehicles
Current status of vascularized composite tissue allotransplantation
Vascularized composite tissue allotransplantation (VCA) offers treatment options of complex functional deficiencies that cannot be repaired with conventional reconstructive methods. VCAs consist of blocks of functional units comprising different tissue types such as skin, bone, muscle, nerves, blood vessels, tendons, ligaments and others, and are thus substantially different from the composition of organ transplants. The field of VCA has made fascinating progresses in the recent past. Among other VCAs, numerous successful hand, face and limb transplants have been performed in the world. At the same time, specific questions in regard to innate and adaptive immunity, consequences of ischemia/reperfusion injury, immunosuppression, preservation, and regenerative capacity remain. In spite of this, the field is poised to make significant advances in the near future
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