6 research outputs found
Chapter Spinel Ferrite Nanoparticles: Correlation of Structure and Magnetism
Filter bank multiâcarrier (FBMC) modulation, as a potential candidate for physical data communication in the fifth generation (5G) wireless networks, has been widely investigated. This chapter focuses on the spectral efficiency analysis of FBMCâbased cognitive radio (CR) systems, and spectral efficiency comparison is conducted with another three types of multiâcarrier modulations: orthogonal frequency division multiplexing (OFDM), generalized frequency division multiplexing (GFDM), and universalâfiltered multiâcarrier (UFMC). In order to well evaluate and compare the spectral efficiency, we propose two resource allocation (RA) algorithms for singleâcell and twoâcell CR systems, respectively. In the singleâcell system, the RA algorithm is divided into two sequential steps, which incorporate subcarrier assignment and power allocation. In the twoâcell system, a noncooperative game is formulated and the multiple access channel (MAC) technique assists to solve the RA problem. The channel state information (CSI) between CR users and licensed users cannot be precisely known in practice, and thus, an estimated CSI is considered by defining a prescribed outage probability of licensed systems. Numerical results show that FBMC can achieve the highest channel capacity compared with another three waveforms
Development of a reference and proficiency chemical list for human steatosis endpoints in vitro
The most prevalent liver disease in humans is non-alcoholic fatty liver disease, characterised by excessive hepatic fat accumulation, or steatosis. The western diet and a sedentary lifestyle are considered to be major influences, but chemical exposure may also play a role. Suspected environmental chemicals of concern include pesticides, plasticizers, metals, and perfluorinated compounds. Here we present a detailed literature analysis of chemicals that may (or may not) be implicated in lipid accumulation in the liver, to provide a basis for developing and optimizing human steatosis-relevant in vitro test methods. Independently collated and reviewed reference and proficiency chemicals are needed to assist in the test method development where an assay is intended to ultimately be taken forward for OECD Test Guideline development purposes. The selection criteria and considerations required for acceptance of proficiency chemical selection for OECD Test Guideline development. (i.e., structural diversity, range of activity including negatives, relevant chemical sectors, global restrictions, etc.) is described herein. Of 160 chemicals initially screened for inclusion, 36 were prioritized for detailed review. Based on the selection criteria and a weight-of-evidence basis, 18 chemicals (9 steatosis inducers, 9 negatives), including some environmental chemicals of concern, were ranked as high priority chemicals to assist in vitro human steatosis test method optimisation and proficiency testing, and inform potential subsequent test method (pre-)validation
Spinel Ferrite Nanoparticles: Correlation of Structure and Magnetism
This chapter focuses on the relationship between structural and magnetic properties of cubic spinel ferrite MFe2O4 (M = Mg, Mn, Fe, Co, Ni, Cu and Zn) nanoparticles (NPs). First, a brief overview of the preparation methods yielding wellâdeveloped NPs is given. Then, key parameters of magnetic NPs representing their structural and magnetic properties are summarized with link to the relevant methods of characterization. Peculiar features of magnetism in real systems of the NPs at atomic, singleâparticle, and mesoscopic level, respectively, are also discussed. Finally, the significant part of the chapter is devoted to the discussion of the structural and magnetic properties of the NPs in the context of the relevant preparation routes. Future outlooks in the field profiting from tailoring of the NP properties by doping or design of coreâshell spinelâonly particles are given
A broadly cross-reactive monoclonal antibody against hepatitis E virus capsid antigen
To generate a hepatitis E virus (HEV) genotype 3 (HEV-3)âspecific monoclonal antibody (mAb), the Escherichia coliâexpressed carboxy-terminal part of its capsid protein was used to immunise BALB/c mice. The immunisation resulted in the induction of HEV-specific antibodies of high titre. The mAb G117-AA4 of IgG1 isotype was obtained showing a strong reactivity with the homologous E. coli, but also yeast-expressed capsid protein of HEV-3. The mAb strongly cross-reacted with ratHEV capsid protein derivatives produced in both expression systems and weaker with an E. coliâexpressed batHEV capsid protein fragment. In addition, the mAb reacted with capsid protein derivatives of genotypes HEV-2 and HEV-4 and common vole hepatitis E virus (cvHEV), produced by the cell-free synthesis in Chinese hamster ovary (CHO) and Spodoptera frugiperda (Sf21) cell lysates. Western blot and line blot reactivity of the mAb with capsid protein derivatives of HEV-1 to HEV-4, cvHEV, ratHEV and batHEV suggested a linear epitope. Use of truncated derivatives of ratHEV capsid protein in ELISA, Western blot, and a Pepscan analysis allowed to map the epitope within a partially surface-exposed region with the amino acid sequence LYTSV. The mAb was also shown to bind to human patientâderived HEV-3 from infected cell culture and to hare HEV-3 and camel HEV-7 capsid proteins from transfected cells by immunofluorescence assay. The novel mAb may serve as a useful tool for further investigations on the pathogenesis of HEV infections and might be used for diagnostic purposes.
Key points
âą The antibody showed cross-reactivity with capsid proteins of different hepeviruses.
âą The linear epitope of the antibody was mapped in a partially surface-exposed region.
âą The antibody detected native HEV-3 antigen in infected mammalian cells
Nanocomposite of CeO2 and High-Coercivity Magnetic Carrier with Large Specific Surface Area
We succeeded in the preparation of CoFe2O4/CeO2 nanocomposites with very high specific surface area (up to 264âg/m2). First, highly crystalline nanoparticles (NPs) of CoFe2O4 (4.7ânm) were prepared by hydrothermal method in water-alcohol-oleic acid system. The oleate surface coating was subsequently modified by ligand exchange to citrate. Then the NPs were embedded in CeO2 using heterogeneous precipitation from diluted Ce3+ sulphate solution. Dried samples were characterized by Powder X-Ray Diffraction, Energy Dispersive X-Ray Analysis, Scanning and Transmission Electron Microscopy, Mössbauer Spectroscopy, and Brunauer-Emmett-Teller method. Moreover, detailed investigation of magnetic properties of the bare NPs and final composite was carried out. We observed homogeneous embedding of the magnetic NPs into the CeO2 without significant change of their size and magnetic properties. We have thus demonstrated that the proposed synthesis method is suitable for preparation of extremely fine CeO2 nanopowders and their nanocomposites with NPs. The morphology and magnetic nature of the obtained nanocomposites make them a promising candidate for magnetoresponsive catalysis
Target Mechanisms of the Cyanotoxin Cylindrospermopsin in Immortalized Human Airway Epithelial Cells
Cylindrospermopsin (CYN) is a cyanobacterial toxin that occurs in aquatic environments worldwide. It is known for its delayed effects in animals and humans such as inhibition of protein synthesis or genotoxicity. The molecular targets and the cell physiological mechanisms of CYN, however, are not well studied. As inhalation of CYN-containing aerosols has been identified as a relevant route of CYN uptake, we analyzed the effects of CYN on protein expression in cultures of immortalized human bronchial epithelial cells (16HBE14oâ) using a proteomic approach. Proteins whose expression levels were affected by CYN belonged to several functional clusters, mainly regulation of protein stability, cellular adhesion and integration in the extracellular matrix, cell proliferation, cell cycle regulation, and completion of cytokinesis. With a few exceptions of upregulated proteins (e.g., ITI inhibitor of serine endopeptidases and mRNA stabilizer PABPC1), CYN mediated the downregulation of many proteins. Among these, centrosomal protein 55 (CEP55) and osteonectin (SPARC) were significantly reduced in their abundance. Results of the detailed semi-quantitative Western blot analyses of SPARC, claudin-6, and CEP55 supported the findings from the proteomic study that epithelial cell adhesion, attenuation of cell proliferation, delayed completion of mitosis, as well as induction of genomic instability are major effects of CYN in eukaryotic cells