Current situation of "non-grain production" of cultivated land in China and the research progress of re-tillage and fertilization technology.

In recent years, the influx of business capital to rural areas, land transfer and adjustment in planting structure have led to the widespread of "non-grain production" of cultivated land in China, which threatens the "1.8 billion mu of arable land protection red line" as well as national food security. Both tillage layer stripped and unstripped are examples of "non-grain production" of cultivated land, which are detrimental to long-term food security because they might reduce soil fertility to varied degrees. In the former case, the original topsoil has been destroyed and the tillage layer is gone. In the latter, there may be impediments such as acidification and salinization. Domestic and international scholars have conducted extensive research on the improvement of degraded soils, including measures with guest soil and soil replacement, the reduction of soil barrier factors, biological fertilization and other measures. There are no systematic research results on the remediation of "non-grain production" of cultivated land. Using data from the National Statistical Yearbook data and literature analysis, we systematically summarized current status of "non-grain production" of cultivated land and key technologies for land improvement, recultivation and fertilization in China, and put forward future directions in this area.

Effects of different remediation methods on phosphorus transformation and availability.

The effects of different heavy metal pollution remediation methods on soil nutrient transformation and soil health remain unclear. In this study, the effects of phytoextraction (PE) and passivation remediation (PR) on Cd-polluted soil phosphorus transformation and availability were compared by pot experiment. The results showed that PE significantly reduced the concentrations of total and available Cd (both H2O-Cd and DTPA-Cd) in soil, PR also decreased available Cd content but had no significant effect on total Cd content. PE slightly increased soil pH and NH4+-N content, while PR significantly increased soil pH, NO3--N and AK content. PE promoted the conversion of stable P (including HCl-Pi and residual-Pt), and increased the content of labile P (including H2O-Pi, NaHCO3-Pi and NaHCO3-Po) and the proportion of moderately labile P (including NaOH-Pi and NaOH-Po), while PR showed the opposite trend. PE showed a higher soil phoC gene abundance and acid phosphatase (ACP) activity, while PR showed a higher phoD gene copies and alkaline phosphatase (ALP) activity. Soil bacteria and phoD-harboring bacteria community was significantly affected by remediation methods and soil types. Compared with PR, PE reduced phoD-harboring bacterial diversity but significantly increased the abundance of genera associated with P dissolution (Streptomyces) and P conversion (Bradyrhizobium and Frankia), both of which were significantly positively correlated with labile P or moderately labile P. In general, compared with PR, PE can effectively remove soil Cd pollution, while maintaining a higher content of labile P and a higher proportion of moderately labile P, which can be considered as a green and sustainable remediation strategy conducive to soil quality.

Comparison and application of wavelet transform and Kalman filtering for denoising in δ13CO2 measurement by tunable diode laser absorption spectroscopy at 2.008 µm: retraction.

The referenced article [Opt. Express25, A896 (2017)] has been retracted.

Comparison and application of wavelet transform and Kalman filtering for denoising in δ13CO2 measurement by tunable diode laser absorption spectroscopy at 2.008 µm.

We propose to use the wavelet transform and Kalman filter methods for processing noise in δ13CO2 measurement using laser absorption spectroscopy at 2.008 µm and they have been shown to be useful tool for reducing the intrinsic noise of the optical system. Through the performance comparison and analysis of these two denoising techniques for the intrinsic noise reduction of optical system, it can be found that the Kalman filter is a more suitable approach for the extraction of gas isotope measurement signal from a contaminated signal.

[Mannan-Binding Lectin Inhibits Candida Albicans-Induced DC Maturation and Cytokine Secretion].

OBJECTIVE: To investigate the effects of mannan-binding lectin (MBL) on the maturation and cytokine secretion of human dendritic cells (DC) induced by Candida albicans (C. albicans). METHODS: The plastic-adherent mononuclear cells were prepared from the blood of healthy adult volunteers. The human peripheral blood mononuclear cells-derived dendritic cells (MNC-DC) were induced by 5-day-culture in medium supplemented with rhGM-CSF and rhIL-4, and then cultured for 2 days in presence or absence of C. albicans at varying concentration of human MBL ranging from 1 to 20 mg/L. DC's shape and characters were observed under inverted microscopy, the expression of CD83 and CD86 on DC was analyzed by FACS. The levels of TNF-α and IL-6 were detected by ELISA. FACS also was used to investigate the interaction of MBL with immature DC(imDC) and C. albicans. Western blot was used to detect C. albicans-induced IκBα phosphorylation and p65/NF-κB translocation in DC. RESULTS: MBL at higher concentrations (10-20 mg/L) down-regulated the expression of CD83 and CD86 on the monocyte-derived dentritic cells(MoDC) induced by C. albicans, and inhibited the production of TNF-α and IL-6 induced by C. albicans. FACS showed that MBL could not only bind to C. albicans but also bind to imDCs in a Ca2+-dependent manner. Western blot showed that MBL could decrease the phosphorylation of IκBα and the nuclear translocation of p65/ NF-κB. CONCLUSION: MBL may inhibit TNF-α and IL-6 production induced by C. albicans in DC through NF-κB signaling pathways, suggesting that MBL can play some roles in the regulation of C. albicans-induced immune response.

[Precision measurement of the birefringence of quartz crystal at 1 310 nm based on the spectroscopic ellipsometer].

In order to get the precision measurement of birefringence of quartz crystal at the communication wavelength 1310nm, based on the principle of precision measurement of phase difference between P and S polarized lights of spectroscopic ellipsometer, a method for precision measurement of birefringence of crystal was designed through the analysis of the Jones matrix under the transmission mode, and the precision measurement of birefringence of quartz crystal at 1 310 nm at room temperature (22 degrees C) was made, the measuring results and error analysis show that the precision reached 10(-6) level, this is the most precise birefringence parameter available, and it is of important significance for the improvement of designing precision of phase retardation devices of quartz.

[Spectral analysis method for precisely measuring specific rotation of quartz].

A spectral analysis method for precisely measuring specific rotation of quartz is proposed. The measuring principle is analyzed by using the method of optical matrix. The result indicates that the specific rotation of quartz can be exactly calculated by measuring the transmittance curve of a sample quartz plate sandwiched between two paralleled polarizing prisms, and the correctness of the method is validated by a designed experiment using a spectrophotometer. The data is analyzed, and the rotary dispersion formula of quartz is fitted. Compared with Lowry' formula, our formula is more accurate in visible spectral scope. Errors in the experiment is analyzed and the result shows that the measuring accuracy will be improved by choosing thicker quartz plate, longer wave band, lower scan speed, and smaller slit width.