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Conductive hydrogels have found large application prospects in the fabrication of flexible multifunctional electronic devices for future-generation wearable human–machine interactions. However, their inferior mechanical strength, low-temperature resistance, and non-recyclability, resulting in the waste of resources, severely hinder their application. Thus, starch bio-based hydrogels have attracted significant attention. Starch is the most abundantly available biodegradable biopolymer. However, starch bio-based hydrogels usually show low toughness, high brittleness and low anti-freezing properties. Thus, to address these issues, herein, glycerol and CaCl2 were concurrently introduced to a starch/poly(vinyl alcohol) (PVA) hydrogel to improve its mechanical, thermal and conductive properties. The effect of glycerol and CaCl2 on the crystallinity, mechanical, thermal and conductive properties was revealed by X-ray diffraction, tensile testing, differential scanning calorimetry, and electrochemical impedance spectroscopy. The thermoplasticity and healing properties of the starch/PVA/glycerol/CaCl2 organohydrogel was also evaluated. Due to the role of glycerol and CaCl2, the compatibility between starch and PVA improved, and thus the as-prepared organohydrogels showed favorable mechanical flexibility and demonstrated anti-freezing ability and long-term stability at ambient temperature. Besides, the abundant hydrogen bonds formed among PVA, starch, glycerol and water endowed the organohydrogels with high stretchability (>790%) and good thermoplasticity. Finally, based on the starch/PVA/glycerol/CaCl2 organohydrogel, a flexible all-solid-state supercapacitor and strain sensor were assembled and their performances were measured. The supercapacitor displayed an areal specific capacitance of 107.2 mF cm−2 at 1 mA cm−2. Moreover, the strain sensor demonstrated high sensitivity (gauge factor of 3.422) and could be directly attached to the human body to detect motion.

Although previous studies have analyzed bacterial diversity and community composition in marine ecosystems, some focused on the relationship between pathogenic bacteria and the composition of bacterial communities in sewage outfalls. The interactions between four pathogenic bacteria (E. coli, Enterococcus, Staphylococcus aureus, fecal coliforms) isolated from the sewage outfall and the bacterial diversity were investigated in the sea adjacent to the Xinghai sewage outlet, China to illustrate the influence of pathogenic bacteria on the bacterial community structure. Higher bacterial diversity was observed in the sewage outlet, and the abundance of pathogenic bacteria and bacterial diversity generally decreased with the increase in the distance from the sewage outlet. Bacterial community structure was mainly influenced by water temperature, conductivity, and dissolved oxygen in summer and winter, while pH, Oxidation-Reduction Potential and salinity were the main factors in autumn. The bacterial abundance had the most significant correlation with E. coli, followed by Enterococcus and fecal coliforms, and the least with Staphylococcus aureus. E. coli (-0.76 < r < 0.79) and Enterococcus (-0.88 < r < 0.77) had similar correlations to the same bacteria, in contrast to Staphylococcus aureus (-0.62 < r < 0.63). The above suggested that pathogenic bacteria may affect the bacterial community structure in the sea adjacent to the sewage outlet besides environmental factors.

To determine the potential of the recreational marine environment as a dissemination vector of antibiotic-resistant microorganisms, the dissemination of antibiotic-resistant E. coli strains isolated from an urban coastal beach was studied. Sixty-nine and thirteen E. coli strains were isolated from the seawater and sand, respectively, in Fujiazhuang bathing beach, China. The average Antibacterial Resistance Index (ARI) value detected in the seawater is approximately three times that in beach sand. All the isolates from the sand were grouped into one cluster and only the isolates from the municipal sewage outlet were classified into three antibiogram clusters that were observed in the hetero-sites of the E. coli isolates. The E. coli strains with multiple antibiotic resistance (58% of total) were prevalent in the seawater, whereas the isolates from the sand were not detected with multiple antibiotic resistance. A significant association (p < 0.05) between all phenotypic and relative genotypic resistance profiles was observed in the isolates, except in the quinolones resistance genotype. The presence of a class 1 integron was significantly correlated with the resistance of E. coli to sulfonamides, streptomycin, and levofloxacin (p < 0.01). This study revealed that the municipal sewage discharge may impact the dissemination of antibiotic-resistant strains in the urban coastal beach, and that the class 1 integrons play an important role in mediating the resistance of E. coli to sulfonamide antibiotics.

Dalian Jinshitan beach was chosen to evaluate the impact of a typhoon on the bacterial community structure and water quality of a marine bathing beach. The concentration of enterococci was determined by the cultivation method. The bacterial community structure and abundance were analyzed using the 16S rDNA next-generation sequencing and qPCR methods. Results showed that the abundance of cultivable enterococci both in alongshore and offshore seawater increased, while it decreased in dry, wet and submerged sand. The water quality deteriorated immediately after the typhoon, and nearly recovered one month after the typhoon. The typhoon event also decreased the bacterial abundance and changed the bacterial community of the beach. Sphingomonadaceae and Rhodobacteraceae significantly increased in seawater and decreased in dry sand immediately after the typhoon. Human and other fecal taxa increased in water and sand. One month after the typhoon, the diversity and many dominant bacterial taxa nearly recovered in seawater and wet sand. Our work shows that the typhoon changed the bacterial dynamics, deteriorated the water quality and proved the transportation of bacterial taxa and input of fecal pollution between water and beach sand or land. Apart from the impact of the typhoon, the geographical location was another important factor in the changed bacterial community.

Using a simple hydrothermal method, we developed a Si@SnS anode material with SnS nanoparticles uniformly attached to the surface of silicon nanoparticles. Utilizing the first charge-discharge reaction mechanism of SnS, combined with the artificial solid electrolyte interphase to improve the solid electrolyte interphase stability of silicon-based materials and the introduction of conductive additives to improve the conductive properties of silicon-based materials, the Si@SnS material exhibits very excellent performance when applied to lithium-ion battery anodes. At a current density of 0.5A.g−1,after two cycles, the overall resistance of the Si@SnS material battery is reduced by nearly 55% relative to the resistance of the pure silicon battery. As a half-cell anode material, the first coulombic efficiency of Si@SnS at a current density of 1A.g−1 reached 85%, and after 200 cycles, it provided a reversible capacity of 1790 mAh.g−1 and a capacity retention rate of 74.6%.