Broadband radar absorbing metamaterial based on Al @SiO2 conductive composite film.

Artificially designed metamaterial structures can manipulate electromagnetic waves, endowing them with exotic physical properties that are not found in natural materials, such as negative refractive index, superlens, and inverse Doppler effect. These characteristics are widely applied in various engineering and military applications. Due to increasingly complex application environments and innovation in radar detection technology, the combination of broadband absorption performance under thin thickness and efficient preparation methods at low cost is often the focus of research on new generation stealth materials. Here, we propose Al@SiO2 composite conductive film metamaterial (Al@SiO2 CCFM) to achieve wideband absorption of electromagnetic waves. This metamaterial structure combines two resonant units, resulting in three absorption bands in the absorption curve. The results show that the absorption rate of the metamaterial is above 90% in the frequency range of 10.6 GHz to 26.0 GHz. The resonance mechanism between multiple structures is a prerequisite for achieving wideband absorption. The materials Al and SiO2 used in Al@SiO2 CCFM are inexpensive and abundant, and the fabrication method is simple. Therefore, they hold great potential for large-scale applications in the multispectral stealth and electromagnetic shielding field.

Structural evolution, digestibility and inhibition on starch digestion of rice glutelin fibril aggregates as affected by incubation.

Structural evolution, digestibility and inhibition on starch digestion of rice glutelin fibril aggregates (RGFAs) as affected by incubation were investigated. Thioflavin T fluorescence intensity of the RGFAs, incubated for 4-day, reached the maximum values, which ranged from 845.00 ± 23.52 to 873.67 ± 50.30. Transmission electron microscopy (TEM) observed that the samples heated for 2 h (2 h fibril) were self-assembled from small glutelin aggregates and a few protofibrils into mature fibrils, the samples heated for 4-10 h (4-10 h fibril) were elongated into long, branched fibrils, and the longer fibrils of 15 h fibril sample dissociated into short fibrils after 4-day of incubation. Compared to rice glutelin, the RGFAs showed thermal stability and resistance to proteolysis. The fluorescence retention rate of 6 h fibril, after incubation for 4-day, was 8.62 ± 0.61 % after in vitro stomach and pancreas digestion, which was the highest among all of the samples. The RGFAs incubated for 1-day displayed much better inhibition effects on starch digestion. This was the first study to clarify the relationship between incubation and physicochemical/functional properties of protein fibrils, which could help understand the preservation of food protein fibrils and their application.

[Establishment and evaluation of a double antibody sandwich ELISA to detect Csa2 protein of Candida albicans].

OBJECTIVE: To establish a double antibody sandwich ELISA for detecting Csa2 protein in Candida albicans infection and evaluate its specificity and sensitivity. METHODS: A recombinant expression vector pPIC9K-Csa2 was constructed and transformed into Pichia pastoris GS115. A large-scale expression of recombinant Csa2 protein (rCsa2) was optimized using methanol, and the protein was purified in P. pastoris expression system. New Zealand Rabbits and guinea pigs were respectively immunized with the purified rCsa2 to prepare polyclonal antisera. The double antibody sandwich ELISA was established by choosing the optimal dilution of coating antisera and detecting antisera. Different concentrations of rCsa2 and culture supernatants of C. albicans collected at different time points were used to evaluate the sensitivity of detection. The specificity of the sandwich ELISA was evaluated by detecting culture supernatants of other three Candida spp, five Aspergillus spp, Cryptococcus neoformans and Penicillium marneffei. RESULTS: The rCsa2 protein was successfully expressed and purified. SDS-PAGE showed that its Mr was 13 300. Western blotting demonstrated that the protein bound to specific antibody. The sensitivity of the sandwich ELISA we established using the high-titer antisera was about 240 pg/mL of rCsa2, and could detect Csa2 protein in the culture supernatant of C. albicans when cultured for as early as 18 hours. There was no cross-reactivity between the culture supernatants of other 10 clinically important fungi and C. albicans. CONCLUSION: The double antibody sandwich ELISA for detecting Csa2 protein has been established with good sensitivity and specificity. Csa2 protein could be used as a new diagnostic marker of C. albicans infection.

The cessation and detoxification effect of tea filters on cigarette smoke.

To treat tobacco addiction, a tea filter was developed and studied for smoking cessation. This work reports the smoking cessation effect of tea when it was used as a component of cigarette filters. In one trial it was found that after using the tea filters for 2 months, the volunteer smokers decreased their cigarette consumption by 56.5%, and 31.7% of them stopped smoking. This work identified a new method and material, tea filter and theanine, which inhibit tobacco and nicotine addiction and provide an effective strategy for treating tobacco addiction.