Observation Study on the Size Distribution of Sand Dust Aerosol Particles over Yinchuan, China

The Yinchuan area, which lies in the eastern part of Northwest China, is one of the main transportation paths and origins of sand dust in China. In order to investigate the aerosol number size distribution and its temporal-spatial evolution over this area, direct solar radiation data taken from September 2012 to October 2013 by a sun photometer CE-318 located at Beifang University of Nationalities (106°29′E, 38°13′N) were analyzed. The particle number size distributions were retrieved from the aerosol optical depth (AOD) by use of the extinction inversion method. The experiment results show that although the averaged size distribution satisfies basically the Junge function, there are two obvious peaks at the particle radius of 0.6 μm and 1.4 μm, respectively. Because sand-dust weather occurs frequently, the particle size distribution in Spring is obviously larger than that in other seasons, which coincides with AOD variation tendency. Moreover, in sand-dust weather the particles number concentration is larger than that of background weather with one order of magnitude, especially for the number of concentration of large particles and giant particles. The research results have very important reference value for quantitative study of the influence of aerosol on atmosphere physics and chemistry process and monitoring of sand-dust weather and air pollution of this area

Assessment of productivity, nutrient uptake and economic benefits of rice under different nitrogen management strategies

Background Integrating a chemical nitrogen (N) fertilizer with an organic fertilizer and using slow-release mechanism are important N management strategies to increase the N utilization efficiency (NUE) and grain yield of rice. However, the performances of both N management strategies on the productivity, the nutrient absorption and utilization efficiency, and the economic benefits of rice have not yet been comprehensively evaluated. Methods A 2-year field experiment was conducted with seven N management strategies without fertilizer (control), 100% conventional N fertilizer (conventional compound fertilizer and urea) (N100), 75% conventional N fertilizer with 25% organic–inorganic compound fertilizer (N75+OICF25), 50% conventional N fertilizer with 50% organic–inorganic compound fertilizer (N50+OICF50), 100% organic–inorganic compound fertilizer (OICF100), slow-release compound fertilizer with urea (SRCF+U), compound fertilizer with sulfur-coated urea (CF+SCU). The responses of the productivity, the nutrient absorption and utilization efficiency, and the economic benefits of rice to the different N management strategies were evaluated. Results CF+SCU performed comparably or better than N100, judging by the grain yield (GY), the N, phosphate (P) and potassium (K) agronomic efficiency (NAE, PAE and KAE), and the apparent N, P and K recovery efficiency (ANRE, APRE and AKRE). SRCF+U significantly increased the GY by an average of 7.7%, the NAE and the ANRE by 23.8 and 26.7%, the PAE and the APRE by 90.6 and 109.3%, and the KAE and the AKRE by 74.2 and 57.7%. The higher GY and nutrient utilization efficiency when using SRCF+U were attributed to the higher total biomass and total nutrient absorption. N75+OICF25 and N50+OICF50 produced a comparable grain yield than N100, whereas a significant yield reduction was observed when using OICF100. Compared with N100, N75+OICF25 resulted in a comparable or higher fertilizer use efficiency (0.3 and 4.7% for NAE and ANRE, 0.3 and 3.2% for PAE and APRE, 0.3 and −2.8% for KAE and AKRE). However, the fertilizer use efficiency when using N50+OICF50 and OICF100 were lower than with N100. The highest net return (NR) (5,845.03 yuan ha−1) and benefit to cost (B:C) ratio (0.34) were obtained when using SRCF+U. The NR and the B:C ratio when using N75+OICF25 were slightly higher than when using N100. However, N50+OICF50 and OICF100 significantly decreased the NR and the B:C ratio compared with N100 by 14.5 and 12.1% and by 35.1 and 29.0%, respectively. Conclusions SRCF+U and CF+SCU enhanced the crop productivity, the nutrient uptake and utilization efficiency, and the economic benefits compared with N100. The comprehensive performance of SRCF+U was better than that of CF+SCU. N75+OICF25 produced almost similar productivity, nutrient uptake and use efficiency compared with N100. It demonstrated that N75+OICF25 stabilized the grain yield production of rice and reduced the input of chemical N fertilizer

Safe and effective subcutaneous adipolysis in minipigs by a collagenase derivative.

Adipocytes attached to the extracellular matrix (ECM) mainly consist of collagen in adipose tissues, while the degradation of ECM by collagenase induces the apoptosis of adipocytes, leading to a decrease in local subcutaneous adipose. To achieve this goal, we are developing a mutant collagenase H (ColH) to remove local subcutaneous fat such as submental fat (SMF). Three vectors were constructed for expressing rColH(FM, mutant for fat melting, with 6xHis tag), rColH(WT, wild-type, with 6xHis tag), and rColH(E451D, E451D mutant, without 6xHis tag) in Escherichia coli. rColH(FM) & rColH(WT) were purified by Ni Sepharose on a laboratory scale, while rColH(E451D) was purified by five chromatography purification steps on a large scale. Then, the stability of rColH(FM) and rColH(WT) was tested by SDS-PAGE to investigate the influence of the E451D mutation on stability. Afterwards, the enzyme kinetics of ColH (mutant or wild-type, with or without His tag) were investigated and compared. Finally, the adipolysis of rColH(E451D) at various doses was tested in vitro and in vivo. The ultrasound results in minipigs suggested that effective adipolysis was induced by rColH(E451D) compared with the negative control, and the histological results suggest dose-dependent fibrosis, necrosis, inflammation and cholesterol cleft formation. These findings indicate the possibility of rColH(E451D) becoming a new injectable drug to safely remove subcutaneous adipose

Greenhouse Gas Emissions, Carbon Footprint, and Grain Yields of Rice-Based Cropping Systems in Eastern China

A multiple cropping system is beneficial for utilizing natural resources, while increasing the grain production and economic outputs. However, its impact on greenhouse gas emissions is unclear. The objective of this study was to evaluate the influence of rice-based cropping systems on methane (CH4) and nitrous oxide (N2O) emissions, the carbon footprint (CF), grain yields, and net economic returns in eastern China. Four treatments were applied: rice–fallow (as a control), rice–milk vetch, rice–wheat, and rice–rapeseed. Methane and N2O emissions were measured every 7 days via static chamber and gas chromatography methods from the 2019 rice season to the 2021 non-rice season. The CF was calculated based on the life cycle assessment. The results showed that multiple cropping systems significantly increased the annual grain yield by 1.2–6.4 t ha−1 and the annual CH4 and N2O emissions by 38–101 kg CH4-C ha−1 and 0.58–1.06 kg N2O-N ha−1, respectively. The average annual net returns for rice–wheat and rice–rapeseed were 131–150% greater than those for rice–milk vetch and rice–fallow. The annual CFs increased in the following order: rice–wheat (19.2 t CO2-eq ha−1) > rice–rapeseed (16.6 t CO2-eq ha−1) > rice–milk vetch (13.9 t CO2-eq ha−1) > rice–fallow (11.5 t CO2-eq ha−1). The CH4 emissions contributed to the largest share of the CF (60.4–68.8%), followed by agricultural inputs (27.2–33.7%) and N2O emissions (2.9–5.9%). Moreover, nitrogen fertilizer accounted for 65.6–72.4% of the indirect greenhouse gas emissions from agricultural inputs. No significant difference in the CF per unit grain yield was observed between the four rice-based cropping systems. The CF per net return of rice–wheat and rice–rapeseed significantly decreased by 37–50% relative to that of rice–fallow and rice–milk vetch. These findings suggest the potential to optimize rice-based cropping systems for environmental sustainability and grain security