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To study the effects of cotton stalk biochar on the regulation of fungal diversity, the structure and function of alkaline rice rhizosphere soil under cadmium pollution was investigated. An outdoor pot experiment was conducted by adding cotton stalk biochar (0%, 1%, and 5%) to an alkaline paddy soil with a cadmium concentration of 0.1 and 8 mg·kg -1 . Taking rice rhizosphere soil as the research object, Illumina HiSeq sequencing was used to analyze the effects of cotton stalk biochar and cadmium pollution on the diversity, structure, abundance, and function of fungi in an alkaline rhizosphere soil, and to explore the correlation between soil environmental factors and the fungal community under the control of cotton stalk biochar. The results showed that:① the application of cotton stalk biochar significantly increased the soil pH, available nutrients, and organic matter, and reduced the content of reducible cadmium in the soil ( P <0.05). ② The distribution of rice rhizosphere soil fungi was mainly Ascomycota, Aphelidiomycota, and Chytridiomycota, which accounted for 57% of all mycophytes. The genus was mainly Mortierella , Alternaria , and Fusarium . There was a significant difference in the α -diversity of the fungal community among the treatments ( P <0.05). In the absence of cotton stalk biochar (C0), the increase in the cadmium concentration reduced the relative abundance and fungal diversity index (Shannon index) of Chytridiomycota, Mortierella , and Alternaria in the soil. Under different concentrations of cadmium (Cd0, Cd1, and Cd8), increasing cotton stalk biochar reduced the fungal community richness index (Chao1 index) and Shannon index. Cadmium pollution resulted in an increase in the relative abundance of Chytridiomycota in the soil, but decreased the abundance of Alternaria . The application of cotton stalk biochar could significantly increase the relative abundance of Chytridiomycota ( P <0.05). Cadmium pollution reduced the abundance of Mortierella and Alternaria , but the application of cotton stalk biochar could increase the relative abundance of Alternaria . Increasing cotton stalk biochar means that soil will have more endophytes, plant pathogens, and saprophytes; while increasing cadmium pollution will reduce endophytes, plant pathogens, and saprophytes in the soil. ③ The main environmental factors affecting the diversity and structure of fungal communities are the available potassium, organic matter, and pH of the soil. The reducible cadmium content, which comprises the largest proportion of cadmium in rice soil, was significantly positively correlated to Rotifera, Aphelidiomycota, and Ascomycota ( P <0.05), but negatively correlated to other mycophytes ( P <0.05). The results indicate that cotton stalk biochar plays a certain role in the microecological regulation of alkaline cadmium-contaminated soil.

Lysophosphatidic acid (LPA) is a small phospholipid that is present in all eukaryotic tissues and blood plasma. As an extracellular signaling molecule, LPA mediates many cellular functions by binding to six known G protein-coupled receptors and activating their downstream signaling pathways. These functions indicate that LPA may play important roles in many biological processes that include organismal development, wound healing, and carcinogenesis. Recently, many studies have found that LPA has various biological effects in different kinds of bone cells. These findings suggest that LPA is a potent regulator of bone development and remodeling and holds promising application potential in bone tissue engineering. Here, we review the recent progress on the biological regulatory function of LPA in bone tissue cells.

A practical gas sensing system utilizing absorption spectrum scanning techniques was developed. Using the narrow-band transmission of a fiber tunable filter (TOF) and wavelength modulation technique, the so-called cross-sensing effects of the traditional spectrum absorption based gas sensor were reduced effectively and thus the target gas was detected sensitively and selectively. In order to reduce the effects of nonlinearity of TOF on the measurement results and improve the system stability in operation, the reflection spectrum of a reference FBG was monitored and employed to control the modulation region and center of TOF wavelength precisely. Moreover, a kind of weak signal detecting circuits was developed to detect the weak response signal of the system with high sensitivity. The properties of the proposed system were demonstrated experimentally by detection of acetylene. Approximate linear relationships between the system responses and the input acetylene concentrations were demonstrated by experiments. The minimum detectable acetylene of 5 x 10(-6), with signal-noise ratio of 3, was also achieved by experiments.

In order to improve the measurement accuracy of FBG sensing system, particle swarm optimization (PSO) algorithm combined with reference FBGs array was applied to investigate the nonlinearity and hysteresis character of Fabry-Parot filter (FPF). A method of modeling the wavelength-voltage relationship of FPF online in each FPF scanning cycle was proposed in the present paper. The feature of particle swarm optimization algorithm such as fast convergence and simple implementation makes the process of modeling wavelength-voltage relationship of FPF be completed with low computing cost and high accuracy. With the set-up model, the absolute error in wavelength detection of FBG sensors was demonstrated by experiments to be as low as 0.03 nm. The structure of the system is compact and the proposed modeling approach has important meaning in FBG sensors system when FPF is used as wavelength demodulator.