Search

In this paper, the theory model of phase noise for microwave photonic link is derived and verified by experiments first, considering both types of flicker and white noises. In order to decrease the phase noise of link, low-phase noise amplifier and high-linear photodiode is applied in microwave photonic link. Based on this model, the effect of phase noise of microwave photonic link on the OEO is also analyzed and we found the lower-phase noise microwave photonic link results in better-characteristics OEO.

The characteristics of two types of opto-electronic oscillators (injection locked and parallel dual-loop) are compared and analyzed firstly in this paper. Based on quasi-linear theory, models of two types of opto-electronic oscillator are built and verified by experiments. After simulation and analysis, we found that the shot-loop injection locked by long-loop opto-electronic oscillator shows the lowest phase noise. The effect of injection power to long loop opto-electronic oscillator on the phase noise is also analyzed and verified by experiments.

Inspired by the supramolecular structure of cellulose, cellulose-gelatin supramolecular hydrogels with high strength and pH-sensitivity were constructed in a basic-based solvent system, ethylene diamine/potassium thiocyanate (EDA/KSCN) with the aid of cyclic freezing-thawing. The investigation on the characteristics of supramolecular hydrogels revealed that repeated freezing-thawing cycles played an important role in the formation of the physical cross-linked supramolecular network structure between cellulose and gelatin. The mechanical properties of supramolecular hydrogels were much higher than pure cellulose and gelatin hydrogel, and the compressive strength was 9.6 times higher than that of pure gelatin hydrogel. The synergistic effect between hydrogen-bonding interaction and the reinforcement of regenerated cellulose nanofibrils (CNF) contributed to the superior mechanical performance. Furthermore, the swelling kinetics tests showed that the supramolecular hydrogels exhibited excellent pH-responsibility, indicating potential applications in biomedical fields. Thus, a straightforward route to construct natural polymer-based hydrogels with supramolecular structure through physical crosslinking strategy without employing hazardous crosslinking agents was developed, paving the way for the design of new types of hydrogels.

This paper proposes and presents the experimental veri cation of a new method for measuring the relative intensity noise (RIN) of a laser. As an important microwave-photonic link (MPL) module, the RIN of a laser contributes to the systematic noise of the intensity modulation and direct detection MPL, thus increasing the phase noise of the transmitted carrier. This physical phenomenon is used to measure the RIN of a laser. Compared with previous methods, the proposed technique is less strongly in uenced by near-DC colored noise. Experimental results show that the MPL-based measurement method proposed in this paper is more accurate in the near-DC frequency band than traditional approaches.

We develop in this paper an Alamouti-type space- time (ST) block code that employs orthogonal M-ary FSK (MFSK) modulation. It is demonstrated that every transmitted symbol in the proposed ST-MFSK scheme can be treated as an implicit pilot symbol, and consequently the receiver can attain close to ideal coherent bit-error performance even in the absence of an explicit channel sounding signal. In addition to employing the popular block-wise static fading model for performance evaluation, we also study the implications of a more realistic fading model whereby the fading gains are allowed to vary from one subinterval to another within a ST code block. It was discovered that an iterative channel estimation strategy has to be adopted to mitigate the cross-talk associated with this refined channel model. The iterative channel estimator, in conjunction with a companion minimum mean square error detector, or a companion maximum likelihood detector, enable the receiver to obtain a bit-error performance similar to that obtained under the block-wise static fading model. In comparison with differential ST-MPSK, the two approaches yield similar error performance in a static fading environment. However, the error performance of differential ST-MPSK deteriorates rapidly as the fade rate increases whereas the performance of ST-MFSK is almost independent of the fade rate. In terms of implementation complexity and delay of the receiver, the proposed coherent ST- MFSK scheme and differential ST-MPSK are very similar, as both approaches employ digital filters of similar lengths. The findings in this paper suggest that despite its larger bandwidth requirement, ST-MFSK is a very attractive alternative space-time signaling format.

Helicobacter pylori is the leading cause of gastritis, peptic ulcer disease and gastric adenocarcinoma and lymphoma in humans. Due to the decreasing efficacy of anti-H. pylori antibiotic therapy in clinical practice, there is renewed interest in the development of anti-H. pylori vaccines. In this study an in silico-based approach was utilized to develop a multi-epitope DNA-prime/peptide-boost immunization strategy using informatics tools. The efficacy of this construct was then assessed as a therapeutic vaccine in a mouse model of gastric cancer induced by chronic H. pylori infection. The multi-epitope vaccine administered intranasally induced a broad immune response as determined by interferon-gamma production in ELISpot assays. This was associated with a significant reduction in H. pylori colonization compared with mice immunized with the same vaccine intramuscularly, given an empty plasmid, or given a whole H. pylori lysate intranasally as the immunogen. Total scores of gastric histological changes were not significantly different among the 4 experimental groups. These results suggest that further development of an epitope-based mucosal vaccine may be beneficial in eradicating H. pylori and reducing the burden of the associated gastric diseases in humans.

Helicobacter pylori is the leading cause of gastritis, peptic ulcer disease and gastric adenocarcinoma and lymphoma in humans. Due to the decreasing efficacy of anti-H. pylori antibiotic therapy in clinical practice, there is renewed interest in the development of anti-H. pylori vaccines. In this study an in silico-based approach was utilized to develop a multi-epitope DNA-prime/peptide-boost immunization strategy using informatics tools. The efficacy of this construct was then assessed as a therapeutic vaccine in a mouse model of gastric cancer induced by chronic H. pylori infection. The multi-epitope vaccine administered intranasally induced a broad immune response as determined by interferon-gamma production in ELISpot assays. This was associated with a significant reduction in H. pylori colonization compared with mice immunized with the same vaccine intramuscularly, given an empty plasmid, or given a whole H. pylori lysate intranasally as the immunogen. Total scores of gastric histological changes were not significantly different among the 4 experimental groups. These results suggest that further development of an epitope-based mucosal vaccine may be beneficial in eradicating H. pylori and reducing the burden of the associated gastric diseases in humans.