Science Letters: Lattice type transmission line of negative refractive index

In this letter, we introduce a novel passive transmission line of negative refractive index （i.e., left-handedness） based on identical symmetrical lattice type structures [thus called ＂lattice type transmission line＂ （LT-TL）]. The dispersion characteristic and the transmission response of the proposed LT-TL are analyzed. While all the other left-handed passive transmission lines are of high pass, the present passive left-handed transmission line is of low pass. Compared with a conventional transmission line, the LT-TL has a phase shift of 180° in the entire wide pass-band.     

A new class of negative refractive index transmission line

We propose a new class of negative refractive index transmission line in which ideal operational amplifiers are applied to form the periodically loaded negative-impedance-converted inductors and capacitors. The phase response of the new trans-mission line is opposite to that of a positive refractive index conventional transmission line. Unlike the existing negative refractive index transmission line,the new negative refractive index transmission line is non-dispersive and thus can lead to many novel applications such as designing new broadband devices.     

Science Letters:Dual structure of composite right/left-handed transmission line

INTRODUCTION An artificial dielectric medium that exhibits si- multaneously negative electric permittivity and magnetic permeability, also known as a left-handed (LH) material, was first envisaged by Veselago, who theoretically predicted that such a medium would exhibit a negative refractive index (NRI) (Veselago, 1968). An artificial NRI medium exhibiting back- ward-wave propagation characteristics (and therefore a negative refractive index) was first realized ex- perimentally in (She…     

Science Letters:A power divider based on a new kind of composite right/left-handed transmission line (CRLH TL) unit

INTRODUCTION Wave propagation in a material with negative magnetic permeability and negative electric permit- tivity was first theoretically analyzed by Veselago (1968). In such a left-handed material (LHM), the electric field E, the magnetic field H and the wave vector k of electromagnetic wave propagation obey the left-hand rule (instead of the right-hand rule for usual materials). After Smith et al.(2000) demon- strated simultaneously negative permeability and permittivity, using cop…     

How to realize a negative refractive index material at the atomic level in an optical frequency range?

INTRODUCTION Recently, a new type of artificial compositematerials (so-called left-handed media or negativerefractive index media) whose electric permittivityand magnetic permeability are simultaneouslynegative (corresponding to a negative refractiveindex) over a certain frequency band has attractedconsiderable attention due to its extraordinaryelectromagnetic properties (Pendry, 2000; Shelbyet al., 2001; Grbic and Eleftheriades, 2004; Chen eal., 2004). The negative refractive inde…     

Dual structure of composite right/left-handed transmission line

A dual structure of composite right/left handed （CRLH） transmission line （TL） is analyzed in which an inductance LR is in parallel with a capacitance CL and a shunt capacitance CR is in series with an inductance LL. Both the distributed and lumped cases are considered. The dispersion diagram and transmission properties of the dual CRLH TL are given and compared with those of a standard CRLH TL. Contrary to the frequency response of a standard CRLH TL, a dual CRLH TL has a left-handed （negative phase shift） band at higher frequencies and a right-handed （positive phase shift） band at lower frequencies. A novel dual-band balun is presented as an application.     

Science Letters:Anodic oxidation of salicylic acid at Ta/BDD electrode

Boron-doped diamond (BDD) film electrodes using Ta as substrates were employed for anodic oxidation of salicylic acid (SA). The effects of operational variables including initial concentration,current density,temperature and pH were examined. The results showed that BDD films deposited on the Ta substrates had high electrocatalytic activity for SA degradation. There was little effect of pH on SA degradation. The current efficiency (CE) was found to be dependent mainly on the initial SA concentration,current density and temperature. Chemical oxygen demand (COD) was reduced from 830 mg/L to 42 mg/L under a current density of 200 A/m2 at 30 °C.     

Science Letters: Application of new tissue microarrayer-ZM-1 without recipient paraffin block

The ZM-1 tissue microarrayer designed by our groups is manufactured in stainless steel and brass and contains many features that make TMA (tissue microarray) paraffin blocks construction faster and more convenient. By means of ZM-1 tissue microarrayer, biopsy needles are used to punch the donor tissue specimens respectively. All the needles with the punched specimen cylinders are arrayed into the array-board, with an array of small holes dug to fit the needles. All the specimen cylinders arraying and the TMA paraffin block shaping are finished in only one step so that the specimen cylinders and the paraffin of the TMA block can very easily be incorporated and the recipient paraffin blocks need not be made in advance, and the paraffin used is the same as that for conventional pathology purpose. ZM-1 tissue microarrayer is easy to be manufactured, does not need any precision location system, and so is much cheaper than the currently used instrument. Our method's relatively cheap and simple ZM- 1 tissue microarrayer technique of constructing TMA paraffin block may facilitate popularization of the TMA technology.     

Science Letters:Proteomic analysis of differentially expressed proteins in mice with concanavalin A-induced hepatitis

Objective:To find new protein biomarkers for the detection and evaluation of liver injury and to analyze the relationship between such proteins and disease progression in concanavalin A (Con A)-induced hepatitis.Methods:Twenty-five mice were randomly divided into five groups:an untreated group,a control group injected with phosphate buffered saline (PBS),and groups with Con A-induced hepatitis evaluated at 1,3 and 6 h.Two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) were used to identif...     

Science Letters:Detection of Catabacter hongkongensis in polluted European water samples

The Catabacteriaceae is a new bacterial family with a unique member: Catabacter hongkongensis is a strictly anaerobic, non-sporulating, Gram-positive coccobacillus that is phylogenetically related to some clostridial clusters. Little is known of its epidemiology and environmental distribution, but the inclusion of its 16S rRNA gene sequence in GenBank has allowed it to be detected qualitatively. As a first approach for prospective surveys, a real-time polymerase chain reaction (PCR) procedure to identify C. hongkongensis has been developed. The presence of Catabacteriaceae in 29 water bodies subjected to possible human or animal impact has been investigated. Four of them were positive. The results confirm that highly polluted water can contain C. hongkongensis.     

Science Letters:Development of supported boron-doping TiO2 catalysts by chemical vapor deposition

In this study, supported nonmetal (boron) doping TiO2 coating photocatalysts were prepared by chemical vapor deposition (CVD) to enhance the activity under visible light irradiation and avoid the recovering of TiO2. Boron atoms were successfully doped into the lattice of TiO2 through CVD, as evidenced from XPS analysis. B-doped TiO2 coating catalysts showed drastic and strong absorption in the visible light range with a red shift in the band gap transition. This novel B-TiO2 coating photocatalyst showed higher photocatalytic activity in methyl orange degradation under visible light irradiation than that of the pure TiO2 photocatalyst.     

Science Letters: Quantification of Helicobacter pylori levels in soil samples from public playgrounds in Spain

Helicobacter pylori are ubiquitous Gram-negative bacteria with a high estimated level of infection in the world populations, but a majority of the infected persons are asymptomatic. This pathogen has been classified by the World Health Organization as a class I carcinogen and recognized as the causal agent of most peptic ulcers and chronic gastritis that might lead to stomach cancer. Although not all the transmission pathways of these bacteria into humans have been properly identified, enough data have sugg...     

Science Letters:Dechlorination mechanism of 2,4-dichlorophenol by Ni/Fe nanoparticles in the presence of humic acid

To understand the feasibility of its application to the in situ remediation of contaminated groundwater, the dechlori-nation of 2,4-dichlorophenol (2,4-DCP) by Ni/Fe nanoparticles in the presence of humic acid (HA) was investigated. We found that, as high performance liquid chromatography (HPLC) was used, the 2,4-DCP was first quickly reduced to o-chlorophenol (o-CP) andp-chlorophenol (p-CP), and then reduced to phenol as the final product. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Ni/Fe nanoparticles, as the HA concentration increased, the removal rate decreased evidently. It also demonstrated that 2,4-DCP was reduced more easily to o-CP than to p-CP, and that the sequence of the tendency in dechlorination of intermediates was p-CP>o-CP. Transmission electron microscope (TEM) showed that HA could act as an adsorbate to compete reactive sites on the surface of Ni/Fe nanoparticles to decrease the dechlorination rate. Also we con-cluded that the dechlorination reaction of 2,4-DCP over Ni/Fe nanoparticles progressed through catalytic reductive dechlorination.     

Science Letters:Effect of nitrogen doping on the reduction of nitric oxide with activated carbon in the presence of oxygen

Nitrogen doping of activated carbon (AC) was performed by annealing both in ammonia and nitric oxide, and the activities of the modified carbons for NO reduction were studied in the presence of oxygen. Results show that nitrogen atoms were incorporated into the carbons, mostly in the form of pyridinic nitrogen or pyridonic nitrogen. The effect of nitrogen doping on the activities of the carbons can be ignored when oxygen is absent, but the doped carbons show desirable activities in the low temperature regime (≤500 ℃) when oxygen is present. The role of the surface nitrogen species is suggested to promote the formation of NO2 in the presence of oxygen, and NO2 can facilitate decomposition of the surface oxygen species in the low temperature regime.     

Science Letters:Crossover randomized controlled trial of the electronic version of the Chinese SF-36

Objectives:to verify the feasibility and reliability of the electronic version of Chinese SF-36 based on the Quality-of-Life-Recorder. Design: A crossover randomized controlled trial, comparing a paper-based and an electronic version of the Chinese SF-36, was conducted. According to generated random numbers, interviewees were asked to fill out either the electronic version or the paper version first. The second version was filled in after a pause of at least 10 min. Settings and participants: One group of 100 medical students at the School of Medicine of Zhejiang University and the other group of 50 outpatients at a clinic for general practice in Hangzhou City (China) were eventually recruited in this study. Results: The acceptance of the electronic version was good (60% of medical students and 84% of outpatients preferred the electronic version). At the level of eight-scale scores, the mean-difference for each scale (except for general health) between the two versions was less than 5%. At the level of 36 questions, the percentage of "exact agreement" ranged within 64%～99%; the percentage of "global agreement" ranged within 72%～99%; 77% of the kappa coefficients demonstrated "good/excellent agreement" and 23% of the kappa coefficients demonstrated "medium agreement". Conclusion: This study, for the first time, can provide empirical basis for the confirmation of the feasibility and reliability of the electronic version of the Chinese SF-36 and may provide an impulse towards widespread deployment of the Quality-of-Life-Recorder in Chinese populations.