Technical advancements and protocol optimization of diffusion-weighted imaging (DWI) in liver

An area of rapid advancement in abdominal MRI is diffusion-weighted imaging (DWI). By measuring diffusion properties of water molecules, DWI is capable of non-invasively probing tissue properties and physiology at cellular and macromolecular level. The integration of DWI as part of abdominal MRI exam allows better lesion characterization and therefore more accurate initial diagnosis and treatment monitoring. One of the most technical challenging, but also most useful abdominal DWI applications is in liver and therefore requires special attention and careful optimization. In this article, the latest technical developments of DWI and its liver applications are reviewed with the explanations of the technical principles, recommendations of the imaging parameters, and examples of clinical applications. More advanced DWI techniques, including Intra-Voxel Incoherent Motion (IVIM) diffusion imaging, anomalous diffusion imaging, and Diffusion Kurtosis Imaging (DKI) are discussed

Influence of a repump laser on a nearly degenerate four-wave-mixing spectrum in atomic vapors

The influence of a repump laser on a nearly degenerate four-wave-mixing (NDFWM) spectrum was investigated. We found the amplitude and line shape of the NDFWM depended strongly on the detuning of the repump field. A five-peak structure was observed. And at some certain repump detuning a dip appeared at the central peak. A rough analysis was proposed to explain this effect

Issue of spatial coherence in MQW based micro-LED simulation

In existing flip-chip LED simulations, the light extraction efficiency is related to the multiple quantum well (MQW) to metal reflector distance because of optical interference. We calculate the contrast using several typical light intensity distributions among the several QWs in MQW. The coherence is obtained analytically. When the luminosity of each QW is equal, the contrast is ∼0, meaning the light is incoherent, contrary to traditional studies. The spatial coherence is important only when the light emission comes from just one QW. As the MQW has a not negligible thickness, the traditional single-dipole model is no longer accurate

A preliminary study on the immune responses of HPV16-E7 by combined intranasal immunization with lymphotoxin

Objectives: Human papillomavirus (HPV) ranks the first cause of cervical cancer. Cervical cancer has high prevalence ratesin women around the world. The HPV-E7 oncoprotein is expressed in cervical cancer and is a target of developing immunotherapiesagainst HPV-associated tumors. However, the antigenicity of this protein is low. Due to this reason, potentadjuvants are required to enhance its therapeutic efficacy. This preliminary study aims to evaluate whether lymphotoxin(LT) could act as an effective immune adjuvant for HPV infection in mice models.Material and methods: Intranasal immunization was used to explore the effect of HPV-E7 and/or LT immune response.After the third intranasal immunization, the titer for the HPV-E7 antibody was detected in serum and vaginal washing fluid.Also, we assessed the expression of chemokine ligand 13 (CXCL13) and Peripheral Node Addressin (PNAd) in the lymphnodes after intranasal immunization with immunohistochemical analysis.Results: compared to HPV-E7 immunization, intranasal immunization with HPV-E7 plus LT significantly increased HPV-E7-specificserum IgG and vaginal IgA titers. Furthermore, the combined use of HPV-E7 and LT strongly induced E7-specific CTLresponses.Conclusions: LT can be effective for intranasal immunized HPV-E7 to improve E7-specific immune responses to HPV infection.It is new approach to eradicate chronic HPV infection capable of inducing an effective anti-infection method

WC@meso-Pt core–shell nanostructures for fuel cells

We developed a facile method to synthesize core–shell WC@meso-Pt nanocatalysts by carburizing ammonium tungstate and copper nitrate via gas–solid reactions, followed by a Pt replacement reaction. The mesoporous nanocomposite displays higher activity and stability towards methanol electrooxidation than commercial Pt/C catalysts

Cloning and characterization of functional keratinassociated protein 5-4 gene in maize

Keratin-associated proteins (KAPs) 5-4 which belongs to keratin-associated protein (KRTAP) type 5 family has two major groups: high/ultrahigh cysteine (HS) and high glycine-tyrosine (HGT). Based on bioinformatic prediction, we experimentally cloned a fragment containingan open reading frame of 1849 bp from maize, which encodes a protein of 408 amino acids. BLAST analysis indicated that KAP5-4 is homologous to the qPE9-1 protein in rice. Conserved domains analysis predicted the presence of five domains. Real time reverse transcriptase polymerase chain reaction (RT-PCR) indicated that the expression of this gene is up-regulated in response to water-deficit stress in the root and leaf.Keywords: Maize, keratin-associated protein 5-4, water-deficit stress.African Journal of Biotechnology Vol. 11(29), pp. 7417-7423, 10 April, 201

Workers and alate queens of Solenopsis geminata share qualitatively similar but quantitatively different venom alkaloid chemistry

Solenopsis geminata group (Hymenoptera: Formicidae) encompasses ant species commonly called fire ants because of their painful sting. The many physiological effects of the venom are caused by 2-methyl-6-alkyl and/or alkenylpiperidine alkaloids. The variation in piperidine alkaloid structures has useful taxonomic characters. The most well studied Solenopsis species is S. invicta, which was accidentally imported into the USA in the 1930s from South America. It quickly spread throughout the southern USA and is now a major invasive pest ant in the USA and in other parts of the world. Interestingly, the invasive S. invicta has largely displaced a native USA fire ant, S. geminata, from the southern USA. We explore the possibility that differences in venom chemistry could be correlated with this displacement. The cis and trans alkaloids from body extracts of workers and alate queens of S. geminata were separated by silica gel chromatography, identified, and quantitated by GC-MS analysis. Both workers and alate queens produce primarily cis- and trans-2-methyl-6-n-undecyl-piperidines, as well as other minor alkaloid components. Imported fire ant, S. invicta, alate queens produce the same alkaloids as S. geminata alate queens, but in contrast S. invicta workers produce piperidine alkaloids with longer side chains, which are purported to be physiologically more effective. These results are discussed in relation to the evolutionary progression of fire ant venom alkaloids and displacement of S. geminata by S. invicta in the USA