Bendable transmission line and amplifier of spoof surface plasmon polaritons at microwave frequencies.

A bendable transmission line (TL) of spoof surface plasmon polaritons (SSPPs) is presented, which can maintain good transmission performance despite of the deformation caused by bending. Such a TL consists of flexible dielectric substrate and ultrathin metallic strip with zigzag decorations that are designed to support the propagation of SSPPs with strong field confinement and low radiation loss. Furthermore, the proposed SSPP TL is used to excite an amplifier chip efficiently, reaching high and stable gains with nearly no degradation of amplification in the bending states. Numerical and experimental results are demonstrated to verify the bendable merits of both passive TL and active amplifier from 12 GHz to 18 GHz. The flexible and stable characteristics of this design may find utility in novel applications like wearable electronics and conformal plasmonic circuits in the microwave frequencies.

Prognostic value of the third lumbar skeletal muscle mass index in patients with liver cirrhosis and ascites.

BACKGROUND & AIMS: The objective nutritional assessment indicators, body mass index (BMI), upper arm muscle circumference (MAMC), and triceps skinfold thickness (TSF), are often limited due to ascites. This study investigated the prognostic value of the third lumbar vertebrae skeletal muscle mass index (L3 SMI) in addition to the objective nutritional evaluation indicators (BMI, MAMC and TSF) in patients with liver cirrhosis and ascites. METHODS: In this retrospective analysis, a total of 147 patients with liver cirrhosis and ascites were included. The L3 SMI, BMI, MAMC and TSF were detected in all patients. The severity of liver disease was assessed by the Model End-Stage Liver Disease (MELD) score and Child-Turcotte-Pugh (CTP) classification. These variables were compared between non-surviving and surviving patients who were classified according to 5-year mortality. RESULTS: Of the 147 patients, 62 (42.2%) died and 85 (57.8%) survived within 5 years. The L3 SMI of patients was significantly lower than that of the normal control group (39.58 ± 7.18 cm2/m2 vs. 53.73 ± 7.92 cm2/m,2p < 0.001). The L3 SMI (OR 4.02; 95% CI 2.17-9.63; p < 0.001), MELD score (OR 2.11; 95% CI 1.12-4.13; p < 0.001) and CTP class (OR 2.69; 95% CI 1.09-5.06; p < 0.001) were independent predictive indicators of 5-year mortality. Furthermore, the performance of the two variables (L3 SMI and MELD) together (AUROC: 0.812) was significantly better than that of MELD alone (AUROC: 0.787) for prediction of 5-year mortality (p < 0.001). CONCLUSION: Compared with MAMC, TSF and BMI, L3 SMI is an independent risk factor for 5-year mortality in patients with liver cirrhosis and ascites. Further nutritional intervention studies are needed to confirm the impact of the L3 SMI index on clinical outcomes.

Integrated spoof plasmonic circuits.

Using a metamaterial consisting of metals with subwavelength surface patterning, one can mimic surface plasmon polaritons (SPPs) and achieve surface waves with subwavelength confinement at microwave and terahertz frequencies, thus bringing most of the advantages associated with the optical SPPs to lower frequencies. Due to the properties of strong field confinement and high local field intensity, spoof SPPs have demonstrated the improved performance for data transmission and device miniaturization in an intensively integrated environment. The distinctive abilities, such as suppression of transmission loss and bending loss, and increase of signal integrity, make spoof SPPs a promising candidate for future generation of electronic circuits and electromagnetic systems. This article reviews the progress in spoof SPPs with a special focus on their applications in circuits from transmission lines to passive and active devices in microwave and terahertz regimes. The integration of versatile spoof SPP devices on a single platform, which is compatible with established electronic circuits, is also discussed.

[Cloning and bioinformatics analysis of recombinant methyl-accepting chemotaxis signal transduction protein of Helicobacter hepaticus].

OBJECTIVE: To clone the gene encoding methyl-accepting chemotaxis signal transduction protein (MCSTP) of Helicobacter hepaticus and analyze the gene structures using bioinformatics methods. METHODS: With the specific primer of Helicobacter hepaticus MCSTP c1977, MCSTP gene was amplified by PCR from the genomic DNA of Helicobacter hepaticus and ligated to the prokaryotic expression vector pET22b(+). After sequencing, the sequence homology and structural feature of MCSTP gene were analyzed by bioinformatics method. RESULTS: A 99% similarity was identified between MCSTP gene cloned and its counterpart in standard Helicobacter hepaticus strain ATCC51449 genome DNA published by GenBank, with only a replacement of A by T at 1160 bp. A low homology was found in the MCSTP genes between Helicobacter hepaticus, Campylobacter jejuni and Helicobacter pylori by bioinformatics analysis, suggesting the specificity of MCSTP gene in Helicobacter hepaticus among the microbes. CONCLUSION: The prokaryotic expression plasmid pET22b(+)/MCSTP is constructed successfully, and the bioinformatics analysis provided evidences and clues for further study of the biological functions and pathogenic mechanism of MCSTP.