76 research outputs found
Actinic imaging of native and programmed defects on a full-field mask
We describe the imaging and characterization of native defects on a full field extreme ultraviolet (EUV) mask, using several reticle and wafer inspection modes. Mask defect images recorded with the SEMA TECH Berkeley Actinic Inspection Tool (AIT), an EUV-wavelength (13.4 nm) actinic microscope, are compared with mask and printed-wafer images collected with scanning electron microscopy (SEM) and deep ultraviolet (DUV) inspection tools. We observed that defects that appear to be opaque in the SEM can be highly transparent to EUV light, and inversely, defects that are mostly transparent to the SEM can be highly opaque to EUV. The nature and composition of these defects, whether they appear on the top surface, within the multilayer coating, or on the substrate as buried bumps or pits, influences both their significance when printed, and their detectability with the available techniques. Actinic inspection quantitatively predicts the characteristics of printed defect images in ways that may not be possible with non-EUV techniques. As a quantitative example, we investigate the main structural characteristics of a buried pit defect based on EUV through-focus imaging
Deguelin Attenuates Reperfusion Injury and Improves Outcome after Orthotopic Lung Transplantation in the Rat
The main goal of adequate organ preservation is to avoid further cellular metabolism during the phase of ischemia. However, modern preservation solutions do rarely achieve this target. In donor organs hypoxia and ischemia induce a broad spectrum of pathologic molecular mechanisms favoring primary graft dysfunction (PGD) after transplantation. Increased hypoxia-induced transcriptional activity leads to increased vascular permeability which in turn is the soil of a reperfusion edema and the enhancement of a pro-inflammatory response in the graft after reperfusion. We hypothesize that inhibition of the respiration chain in mitochondria and thus inhibition of the hypoxia induced mechanisms might reduce reperfusion edema and consecutively improve survival in vivo. In this study we demonstrate that the rotenoid Deguelin reduces the expression of hypoxia induced target genes, and especially VEGF-A, dose-dependently in hypoxic human lung derived cells. Furthermore, Deguelin significantly suppresses the mRNA expression of the HIF target genes VEGF-A, the pro-inflammatory CXCR4 and ICAM-1 in ischemic lungs vs. control lungs. After lung transplantation, the VEGF-A induced reperfusion-edema is significantly lower in Deguelin-treated animals than in controls. Deguelin-treated rats exhibit a significantly increased survival-rate after transplantation. Additionally, a downregulation of the pro-inflammatory molecules ICAM-1 and CXCR4 and an increase in the recruitment of immunomodulatory monocytes (CD163+ and CD68+) to the transplanted organ involving the IL4 pathway was observed. Therefore, we conclude that ischemic periods preceding reperfusion are mainly responsible for the increased vascular permeability via upregulation of VEGF. Together with this, the resulting endothelial dysfunction also enhances inflammation and consequently lung dysfunction. Deguelin significantly decreases a VEGF-A induced reperfusion edema, induces the recruitment of immunomodulatory monocytes and thus improves organ function and survival after lung transplantation by interfering with hypoxia induced signaling
Morphological variation in Staurastrum rotula (Zygnemaphyceae, Desmidiales) in the deepest natural Brazilian lake: essence or accident?
Comparing early adolescents’ positive bystander responses to cyberbullying and traditional bullying: the impact of severity and gender
Young people are frequently exposed to bullying events in the offline and online domain. Witnesses to these incidents act as bystanders and play a pivotal role in reducing or encouraging bullying behaviour. The present study examined 868 (47.2% female) 11-13-year-old early adolescent pupils’ bystander responses across a series of hypothetical vignettes based on traditional and cyberbullying events. The vignettes experimentally controlled for severity across mild, moderate, and severe scenarios. The findings showed positive bystander responses (PBRs) were higher in cyberbullying than traditional bullying incidents. Bullying severity impacted on PBRs, in that PBRs increased across mild, moderate, and severe incidents, consistent across traditional and cyberbullying. Females exhibited more PBRs across both types of bullying. Findings are discussed in relation to practical applications within the school. Strategies to encourage PBRs to all forms of bullying should be at the forefront of bullying intervention methods
Coordinated medium access in wireless industrial D2D networks: Fast handshake procedures based on stable matching variants
We study the medium access of wireless device-to-device links in industrial factory environments characterized by high reliability and low latency communication requirements. We propose fast handshake procedures between the devices and a coordinator which allows several transmitter-receiver pairs to access the same frequency resource within a cell. Our framework relies on game-theoretic stable matching. We exploit many-to-one and many-to-many matching variants together with truncated schemes to achieve low-complex implementations. Furthermore, we consider power allocation with SINR guarantees to ensure reliable data transmission on resources under frequency reuse. Performance results for industrial indoor propagation at 5.2 GHz complement previous analytical work
Professional Live Audio Production: A Highly Synchronized Use Case for 5G URLLC Systems
The fifth generation of cellular mobile communication networks is on the horizon and aims to integrate new vertical markets. In this article, we discuss professional wireless audio systems used for live productions as a future use case for 5G. Wireless live audio productions require high communication reliability as well as ultra-low signal delay. Furthermore, these services demand strict synchronization of devices to function properly. The need for low latency and for precise time and phase synchronization goes beyond what is currently under discussion in the context of URLLC. We seize on this aspect, discuss how isochronous data transmission can be implemented and integrated into 5G networks, and show similarities with other 5G verticals such as industrial automation
Joint multicell subchannel assignment with interference control and resource fairness in multiband OFDMA cellular networks
Optimized distribution of downlink resources to users is a key challenge in future cellular communication systems with increasing base station density. Mobile broadband networks are expected to operate under frequency reuse factor one and are therefore interference-limited. We derive a novel framework for resource-fair sum rate maximization in OFDMA multicell deployments with single antenna links where power allocation among subchannels is predefined. The framework holds for multiband scenarios with non-contiguously aggregated carriers. Our proposed algorithm for joint subchannel scheduling is based on semidefinite reformulation and programming techniques. It has a significant contribution by taking into account active control of inter-cell interference on shared frequency resources. We achieve throughput bounds and near-optimal feasible sum rates under guarantee of interference temperature constraints by extensively exploiting all degrees of the three-dimensional binary assignment problem. We give simulation results that are compliant with wireless propagation assumptions under the Long Term Evolution (LTE) standard. Moreover, we show that the network performance can gain substantial improvements by our scheme when compared to the current generation of wireless networks where subchannel assignment has distributed implementations among locally operating cell sites
System level performance of cellular networks utilizing ASA/LSA mechanisms
Flexible and efficient spectrum usage in cellular communication systems is a key to meet the service demand of forthcoming 4G and 5G networks by 2020. Recent wide-band power measurements in an urban environment show that spectrum below 6 GHz is still under-utilized. Licensed shared access (LSA) is one technique which can be deployed to make use of these valuable resources. In this paper we highlight cell-planning aspects for the implementation of licensed shared access (LSA) in LTE cellular networks. Different cellular deployments are evaluated by means of system-level simulations. Numerical results show that transmit power, antenna type and orientation, as well as antenna downtilt should be carefully evaluated during the planning of spectrum sharing deployments using LSA in cellular wireless
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