Polarized thermal radiation by layer-by-layer metallic emitters with sub-wavelength grating

Metallic thermal emitters consisting of two layers of differently structured nickel gratings on a homogeneous nickel layer are fabricated by soft lithography and studied for polarized thermal radiation. A thermal emitter in combination with a sub-wavelength grating shows a high extinction ratio, with a maximum value close to 5, in a wide mid-infrared range from 3.2 to 7.8 µm, as well as high emissivity up to 0.65 at a wavelength of 3.7µm. All measurements show good agreement with theoretical predictions. Numerical simulations reveal that a high electric field exists within the localized air space surrounded by the gratings and the intensified electric-field is only observed for the polarizations perpendicular to the top sub-wavelength grating. This result suggests how the emissivity of a metal can be selectively enhanced at a certain range of wavelengths for a given polarization

Photonic crystal: energy-related applications

We review recent work on photonic-crystal fabrication using soft-lithography techniques. We consider applications of the resulting structures in energy-related areas such as lighting and solar-energy harvesting. In general, our aim is to introduce the reader to the concepts of photonic crystals, describe their history, development, and fabrication techniques and discuss a selection of energy-related applications

Delayed Infrarenal Aortic Pseudoaneurysm Treated by Endovascular Stent Graft in Pyogenic Spondylitis

A 61-year-old male patient with pyogenic spondylodiscitis and epidural and psoas abscesses underwent posterior decompression, debridement, and instrumented fusion, followed by anterior debridement and reconstruction. Sudden onset flank pain was diagnosed 7 weeks postoperatively and was determined to be a pseudoaneurysm located at the aorta inferior to the renal artery and superior to the aortic bifurcation area. An endovascular stent graft was applied to successfully treat the pseudoaneurysm. Postoperative recovery was uneventful and infection status was stabilized

Approaches toward efficient and stable electron extraction contact in organic photovoltaic cells: Inspiration from organic light-emitting diodes

Electron extraction contact in organic photovoltaic cells (OPVs) is very important to extract electrons from the active layer efficiently, improve the open-circuit voltage, and thus improve the power conversion efficiency. This paper reviews the various approaches to form an electron extraction contact for better power conversion efficiency and device lifetime, especially in organic bulk heterojunction photovoltaic cells based on conjugated polymer: fullerene blends. We discuss the roles of thin metal fluorides, a thin polymeric layer, and a solution processed metal oxide layer at the interface between the photoactive layer and the negative electrode for efficient and stable electron extraction contact in OPVs. In addition, we discuss the effects of various metallic negative electrodes in OPVs in terms of device efficiency and stability. Since these approaches are well established in organic light-emitting diodes, they can be exploited to accelerate research in device engineering to improve device performance.N

An Enhanced Group Key-Based Security Protocol to Protect 5G SON Against FBS

Network operators are attempting many innovations and changes in 5G using self-organizing networks (SON). The SON operates on the measurement reports (MR), which are obtained from user equipment (UE) and secured against malware and userspace programs. However, the synchronization signal block that the UE relies on to measure the wireless environment configured by a base station is not authenticated. As a result, the UE will likely gauge the wrong wireless environment configured by a false base station (FBS) and transmit the corresponding MR to the serving base station, which poisons the data used for 5G SONs. Therefore, the serving base stations must verify the authenticity of the MR. The 3GPP has advocated numerous solutions for this issue, including the use of public key certificates, identity-based keys, and group keys. Although the solution leveraging group keys have better efficiency and practicality than the other two, they are vulnerable to security threats caused by key leaks via insiders or malicious UE. In this paper, we analyze these security issues and propose an improved group key protocol that uses a new network function, called a broadcast message authentication network function (BMANF), which validates broadcasted messages on behalf of the UE. The protocol operates in two phases: initial and verification. During the initial phase, the 5G core network distributes a shared secret key to the BMANF and UE, allowing the latter to request an authentication ticket from the former. During the verification phase, the UE requests the BMANF to validate the broadcasted messages received from base stations using the ticket and its corresponding shared key. For evaluation, we formally verified the proposed protocol, which was then compared with alternative methods in terms of computing cost. As a result, the proposed protocol fulfills the security requirements and shows a lower overhead than the alternatives

Apoptosis-induced effects of extract from Artemisia annua Linné by modulating PTEN/p53/PDK1/Akt/ signal pathways through PTEN/p53-independent manner in HCT116 colon cancer cells

Abstract Background The extracts from Artemisia annua Linné (AAE) has been known to possess various functions including anti-bacterial, anti-virus and anti-oxidant effects. However, the mechanism of those effects of AAE is not well known. Pursuantly, we determined the apoptotic effects of extract of AAE in HCT116 cell. In this study, we suggested that AAE may exert cancer cell apoptosis through PTEN/PDK1/Akt/p53signal pathway and mitochondria-mediated apoptotic proteins. Methods We measured 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, lactate dehydrogenase (LDH) assay, Hoechst 33342 staining, Annexin V-PI staining, Mitopotential assay, immunofluorescence (IF) and Western blotting. Accordingly, our study showed that AAE treatment to HCT116 cells resulted in inhibition of PDK1, Akt, MDM2, Bcl-2, and pro-caspase 3 as well as activation of PTEN, p53-upregulated modulator of apoptosis (PUMA), Bax and Bak expression. Also we measured in vivo assay that xenograft model, H&E assay, TUNEL assay and IHC. Results AAE induced apoptosis via PTEN/p53/PDK1/Akt signal pathways through PTEN/p53-independent manner. AAE inhibit cell viability and increase LDH release in HCT116 colon cancer cell. Also, AAE increase apoptotic bodies, caspase −3,7 activation and reduces mitochondria membrane potential. AAE regulates cytochrome c translocation to the cytoplasm and Bax translocation to the mitochondrial membrane in an Immunofluorescence staining and increase PTEN and p53 expression in an in vivo tumor xenograft model. To elucidate the role of the PTEN/p53/PDK1/Akt signal pathways in cancer control, we conditionally inactivated PTEN/p53/PDK1/Akt signal pathways. We used inhibitors of PTEN, p53, PDK1, Akt. In consequence, these results indicate that AAE induced apoptosis by means of a mitochondrial event through the regulation of proteins such as Bax, Bak and cytochrome c in PDK1/Akt signaling pathways via PTEM/p53-independent manner. Conclusions We confirmed the apoptotic effect of extracts of AAE by Modulating PTEN/p53/PDK1/Akt/Signal Pathways through PTEN/p53-independent pathwaysin HCT116 colon cancer cell

Removal of nitrogen by a layered soil infiltration system during intermittent storm events. Chemosphere

The fates of various nitrogen species were investigated in a layered biological infiltration system under an intermittently wetting regime. The layered system consisted of a mulch layer, coarse soil layer (CSL), and fine soil layer (FSL). The effects of soil texture were assessed focusing on the infiltration rate and the removal of inorganic nitrogen species. The infiltration rate drastically decreased when the uniformity coefficient was larger than four. The ammonium in the synthetic runoff was shown to be removed via adsorption during the stormwater dosing and nitrification during subsequent dry days. Stable ammonium adsorption was observed when the silt and clay content of CSL was greater than 3%. This study revealed that the nitrate leaching was caused by nitrification during dry days. Various patterns of nitrate flushing were observed depending on the soil configuration. The washout of nitrate was more severe as the silt/clay content of the CSL was greater. However, proper layering of soil proved to enhance the nitrate removal. Consequently, a strictly sandy CSL over FSL with a silt and clay content of 10% was the best configuration for the removal of ammonium and nitrate. (C) 2009 Elsevier Ltd. All rights reserved.1136sciescopu

Photonic crystal: energy-related applications

We review recent work on photonic-crystal fabrication using soft-lithography techniques. We consider applications of the resulting structures in energy-related areas such as lighting and solar-energy harvesting. In general, our aim is to introduce the reader to the concepts of photonic crystals, describe their history, development, and fabrication techniques and discuss a selection of energy-related applications.This article is from Journal of Photonics for Energy 2 (2012): 021012, doi:10.1117/1.JPE.2.021012. Posted with permission.</p

Polarized thermal radiation by layer-by-layer metallic emitters with sub-wavelength grating

Metallic thermal emitters consisting of two layers of differently structured nickel gratings on a homogeneous nickel layer are fabricated by soft lithography and studied for polarized thermal radiation. A thermal emitter in combination with a sub-wavelength grating shows a high extinction ratio, with a maximum value close to 5, in a wide mid-infrared range from 3.2 to 7.8 µm, as well as high emissivity up to 0.65 at a wavelength of 3.7µm. All measurements show good agreement with theoretical predictions. Numerical simulations reveal that a high electric field exists within the localized air space surrounded by the gratings and the intensified electric-field is only observed for the polarizations perpendicular to the top sub-wavelength grating. This result suggests how the emissivity of a metal can be selectively enhanced at a certain range of wavelengths for a given polarization.This article is from Optics Express 16 (2008): 8742–8747, doi:10.1364/OE.16.008742. Posted with permission.</p