Highly asymmetric transmission of linearly polarized waves realized with a multilayered structure including chiral metamaterials

Cataloged from PDF version of article.We numerically and experimentally demonstrate highly asymmetric transmission of linearly polarized waves with a multilayered metallic structure. The whole structure has a subwavelength thickness and consists of a thin slab of chiral metamaterial sandwiched between two 90° twisted linear polarizers. The chiral metamaterial is made of two sets of twisting cross wires that can rotate the polarization by 90° at resonance, and the two linear polarizers are simple metallic grating polarizers. The operation principle of the whole structure can be well interpreted by using the Jones matrix method. Our experimental results also verify that chiral metamaterials can be safely integrated into complex structures and treated as an effective medium as long as their resonant modes are not affected by the environment. © 2014 IOP Publishing Ltd

Chiral metamaterials: from optical activity and negative refractive index to asymmetric transmission

Cataloged from PDF version of article.We summarize the progress in the development and application of chiral metamaterials. After a brief review of the salient features of chiral metamaterials, such as giant optical activity, circular dichroism, and negative refractive index, the common method for the retrieval of effective parameters for chiral metamaterials is surveyed. Then, we introduce some typical chiral structures, e.g., chiral metamaterial consisting of split ring resonators, complementary chiral metamaterial, and composite chiral metamaterial, on the basis of the studies of the authors’ group. The coupling effect during the construction of bulk chiral metamaterials is mentioned and discussed. We introduce the application of bianisotropic chiral structures in the field of asymmetric transmission. Finally, we mention a few directions for future research on chiral metamaterials

The design of green supply chains under carbon policies: A literature review of quantitative models

Carbon footprinting of products and services is getting increasing attention due to the growing emphasis on carbon related policies in many countries. As a result, many enterprises are focusing on the design of green supply chains (GSCs) with research on supply chains (SCs) focused not only on cost efficiency, but also on its environmental consequences. The review presented in this paper focuses on the implications of carbon policies on SCs. The concept of content analysis is used to retrieve and analyze the information regarding drivers (carbon policies), actors (for example, manufacturers and retailers), methodologies (mathematical modeling techniques), decision-making contexts (such as, facility location and order quantity), and emission reduction opportunities. The review shows a lack of emissions analysis of SCs that face carbon policies in different countries. The research also focuses on the design of carbon policies for emissions reduction in different operating situations. Some possible research directions are also discussed at the end of this review.A NPRP award NPRP No.5-1284-5-198 from the Qatar National Research Fund (a member of The Qatar Foundation).Scopu

First Report of Columbia Root-Knot Nematode (\u3ci\u3eMeloidogyne chitwoodi\u3c/i\u3e) in Potato in Turkey

Columbia root-knot nematode, Meloidogyne chitwoodi Golden et al., was identified from potatoes, Solanum tuberosum L., collected from Nigde Province, Turkey in September 2006. Seed potatoes are the most likely source for this introduction. The nematode is currently found to be infecting potatoes grown in the Netherlands, Portugal, Belgium, Germany, the United States, Mexico, South Africa, and Argentina. M. chitwoodi acquired a quarantine status in Europe (1) because of its potential to become established worldwide and its high damage probability. Some countries prohibit import of both seed and table stock potatoes originating in states known to harbor M. chitwoodi. Lesions on the potatoes had discrete brown coloration with white central spots in the outer 1 cm of the tuber flesh

First Report of Columbia Root-Knot Nematode (\u3ci\u3eMeloidogyne chitwoodi\u3c/i\u3e) in Potato in Turkey

Columbia root-knot nematode, Meloidogyne chitwoodi Golden et al., was identified from potatoes, Solanum tuberosum L., collected from Nigde Province, Turkey in September 2006. Seed potatoes are the most likely source for this introduction. The nematode is currently found to be infecting potatoes grown in the Netherlands, Portugal, Belgium, Germany, the United States, Mexico, South Africa, and Argentina. M. chitwoodi acquired a quarantine status in Europe (1) because of its potential to become established worldwide and its high damage probability. Some countries prohibit import of both seed and table stock potatoes originating in states known to harbor M. chitwoodi. Lesions on the potatoes had discrete brown coloration with white central spots in the outer 1 cm of the tuber flesh

Chiral metamaterials: From negative index to asymmetric transmission

Chiral metamaterials are attractive for their intriguing properties such as negative refractive index, optical activity and circular dichroism, and asymmetric transmission. In this paper, we review the research we have conducted for the purpose of investigating these exciting properties. © 2013 EurAAP

Zoledronic acid induces apoptosis via stimulating the expressions of ERN1, TLR2, and IRF5 genes in glioma cells

Glioblastoma multiforme (GBM) is the most common and aggressive brain tumor that affects older people. Although the current therapeutic approaches for GBM include surgical resection, radiotherapy, and chemotherapeutic agent temozolomide, the median survival of patients is 14.6 months because of its aggressiveness. Zoledronic acid (ZA) is a nitrogen-containing bisphosphonate that exhibited anticancer activity in different cancers. The purpose of this study was to assess the potential effect of ZA in distinct signal transduction pathways in U87-MG cells. In this study, experiments performed on U87-MG cell line (Human glioblastoma-astrocytoma, epithelial-like cell line) which is an in vitro model of human glioblastoma cells to examine the cytotoxic and apoptotic effects of ZA. IC50 dose of ZA, 25 μM, applied on U87-MG cells during 72 h. ApoDIRECT In Situ DNA Fragmentation Assay was used to investigate apoptosis of U87MG cells. The quantitative reverse transcription polymerase chain reaction (qRT-PCR) (LightCycler480 System) was carried out for 48 gene expression like NF-κB, Toll-like receptors, cytokines, and inteferons. Our results indicated that ZA (IC50 dose) increased apoptosis 1.27-fold in U87MG cells according to control cells. According to qRT-PCR data, expression levels of the endoplasmic reticulum-nuclei-1 (ERN1), Toll-like receptor 2 (TLR2), and human IFN regulatory factor 5 (IRF5) tumor suppressor genes elevated 2.05-, 2.08-, and 2.3-fold by ZA, respectively, in U87MG cells. Our recent results indicated that ZA have a key role in GBM progression and might be considered as a potential agent in glioma treatment. © 2015, International Society of Oncology and BioMarkers (ISOBM)

Biocatalytic protein membranes fabricated by electrospinning

In this study, a protein-based catalytic membrane was produced by electrospinning. Membrane activity was characterised in terms of response current for various glucose concentrations. We focused on the preparation of a scaffold by converting a globular protein to other structural forms using catastrophic solvents. A scaffolding protein, bovine serum albumin, and an enzyme, glucose oxidase (GOD), were selected as a model natural carrier matrix and a biologically active agent, respectively. Beta-mercaptoethanol (β-ME) was used to convert the globular protein to an amyloid-like form. A structural stabilising agent, 2,2,2-triflouroethanol (TFE), was used to maintain the final α-helical structure of the amyloid-like protein. The TFE:PBS (phosphate-buffered saline) ratio and various electrospinning parameters were analysed to minimise activity loss. Using this approach, we applied electrospinning to an active enzyme to obtain biocatalytic nanofibrous membranes. After optimising the protein electrospinning process, the activities of the protein nanofibrous membranes were monitored. GOD remained active in the new membrane structure. The highest enzyme activity was observed for the membranes prepared with a 1.5:1 (v:v) TFE:PBS solvent ratio. In that particular case, the immobilized enzyme created a current of 0.7 μA and the apparent activity was 2547 ± 132 U/m2. © 2016, Elsevier B.V. All rights reserved