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In this paper, we propose a dual linear polarization fringe fitting method which can be used in the next generation VLBI system (VLBI global observing system, VGOS). The legacy geodetic VLBI observation mode is dedicated to the right circular polarization (RCP), which differs from the dual linear polarization adopted in the VGOS system. The algorithm presented in this work consists of the calibration part and combined fringe fitting part. In the calibration part, we derive the intermediate frequency (IF) delay and phase calibration information from each polarization product by carrying out fringe fitting on a strong reference source. Then this information is applied to the target sources. In the combined fringe fitting part, we combine 4 polarization products into the Pseudo-Stokes Intensity and in the meanwhile search for the appropriate differential parallactic angle, so as to maximize the amplitude of the intensity and therefore derive the delay as observable. Compared with single polarization, the combined product yields higher signal-to-noise ratio (SNR) and smaller fringe phase scatter.

Since the surface immunogenic protein (Sip) of group B streptococcus was identified, it's immunogenicity and its potential as a universal vaccine candidate has been evaluated extensively. We developed recombinant Sip protein and used it for monoclonal antibody generation to develop immunochromatographic test kit for GBS detection. The test of bacteria and culture media revealed the correlation between Sip protein expression and diagnosis discrepancy, which has never been reported. Furthermore, not only the surface accessibility of the Sip protein may vary from strains or serotypes; the secretion level of Sip protein may also vary.

Background Fecal occult bloodtest (FOBT) plays an important role in the diagnosis of gastrointestinal diseases. The sensitivities of current FOBT methods are still not satisfactory. The aim of this study is to develop a combined human transferrin (HTf)-hemoglobin (HHb) lateral flow assay (LFA) for accurate and rapid FOBT. Methods Monoclonal antibodies (MAbs) targeting HTf were developed by conventional methods and paired using LFA strips. The best HTf MAb pair was chosen according to the overall performance on testing limit and specificity. Meanwhile, HHb LFA strips were prepared using previously developed HHb MAbs. The testing limit and specificity were characterized. Based on the selected HTf MAb pair and the verified HHb MAb pair, combined HTf-HHb strips were developed. The combined HTf-HHb strips were used for FOBT of 400 human fecal samples, including 200 gastrointestinal bleeding specimens and 200 healthy subjects. For comparison, the homemade individual HTf and HHb strips, as well as three kinds of commercial FOBT strips, were also used for the FOBT. Results Two MAb pairs targeting HTf were developed for LFA. Two types of HTf strips were prepared accordingly. The type I was chosen due to its lower detection limit. Using the type I HTf MAb pair and the verified HHb- MAb pair, the combined HTf-HHb strips could detect the HTf at concentrations between 1 ng/mL and 1 x 106 ng/mL and the HHb between 10 ng/mL and 2.5 x 106 ng/mL. Compared to individual HTf and HHb strips and three kinds of commercial strips, the combined strips showed the highest diagnostic sensitivity in FOBT (96.0%). The specificity was a satisfactory 99%. Conclusions Our combined HTf-HHb test strips are a very promising product for accurate and rapid FOBT.

We propose a simple elastic-plastic contact model by considering the interaction of two spheres in the normal direction, for use in discrete element method (DEM) simulations of geomaterials. This model has been developed by using the finite element method (FEM) and nonlinear fitting methods, in the form of power-law relation of the dimensionless normal force and displacement. Only four parameters are needed for each loading-unloading contact process between two spheres, which are relevant to material properties evaluated by FEM simulations. Within the given range of material properties, those four parameters can be quickly accessed by interpolating the data appended or by regression functions supplied. Instead of the Von Mises (V-M) yield criterion, the Drucker–Prager (D-P) criterion is used to describe the yield behavior of contacting spheres in this model. The D-P criterion takes the effects of confining pressure, the intermediate principal stress, and strain rate into consideration; thus, this model can be used for DEM simulation of geomaterials as well as other granular materials with pressure sensitivity.

Vibrio parahaemolyticus is widely present in brackish water all over the world, causing infections in certain aquatic animals. It is also a foodborne pathogen that causes diarrhea in humans. The aim of this study is to develop an immunochromatographic lateral flow assay (LFA) for rapid detection of V. parahaemolyticus in both aquatic products and human feces of diarrheal patients. Two monoclonal antibody (MAb) pairs, GA1a-IC9 and IC9-KB4c, were developed and proven to be highly specific and sensitive to V. parahaemolyticus. Based on the two MAb pairs, two types of LFA strips were prepared. Their testing limits for V. parahaemolyticus culture were both 1.2×103CFU/ml. The diagnostic sensitivities and specificities were both 100% for the 32 tested microbial species, including 6 Vibrio species. Subsequently, the LFA strips were used to test Whiteleg shrimps and human feces. The type II strip showed a higher diagnostic sensitivity. Its sensitivity and specificity for hepatopancreas and fecal samples from 13 Whiteleg shrimps and fecal samples from 146 human diarrheal patients were all 100%. In conclusion, our homemade type II LFA is a very promising testing device for rapid and convenient detection of V. parahaemolyticus infection not only in aquatic animals, but also in human diarrheal patients. This sensitive immunochromtographic LFA allows rapid detection of V. parahaemolyticus without requirement of culture enrichment.