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The surface of Bacillus megaterium was modified by coating sodium alginate. The modified B. megaterium before and after adsorption were characterized by SEM, FTIR and XPS. The effects of pH, reaction time, initial U(VI) concentration and adsorbent dosage on the adsorption of U(VI) by the modified B. megaterium were studied by batch adsorption experiments. The adsorption process was studied by pseudo-first-order kinetics and pseudo-second-order kinetic models, Langmuir and Freundlich isotherms. The results showed that the maximum adsorption capacity of U(VI) was 74.61 mg g −1 under the conditions of pH 5.0, adsorbent 0.2 g l −1 , 30°C and initial U(VI) concentration of 15 mg l −1 . The adsorption process accords with pseudo-first-order kinetics and Langmuir isotherm. The adsorption capacity of U(VI) by the modified B. megaterium was still higher than 80% after five times of desorption and reuse experiments. In conclusion, the sodium alginate modified B. megaterium was an ideal material for U(VI) biosorption.

Planetary gearbox is widely used in various low-speed machines due to its large transmission ratio. However, the gears in a planetary gearbox are prone to the mechanical faults due to the complex dynamic heavy load. Vibration frequencies caused by an early tooth root crack of sun gear are usually difficult to accurately extract, so its fault diagnosis is one of the main challenges of planetary gearbox reliability. In this paper, a simplified tooth root crack model of sun gear is proposed, and then a rigid-flexible coupled dynamics model of the whole planetary gear system is constructed. By the numerical simulation, the fault frequencies caused by a tooth root crack of sun gear are obtained. A Variational Mode Decomposition (VMD) algorithm for the vibration frequency extraction is proposed. The measured vibration signals are decomposed into the sparse Intrinsic Mode Functions (IMFs) by the VMD, and then the IMFs are further analyzed by the spectral method to accurately extract the crack-induced frequency components. The experimental results show that the proposed dynamics model and VMD method are feasible; an error between the characteristic frequencies from the tested signal analysis and the theoretical calculation is less than 1%.

The potato early blight was caused by Alternaria solani (Aso). At present, potato early blight resistant varieties are lacking. The experiment of Aso inoculation on a.k.a. Favorita showed that the content of chlorophyll decreased continuously within 2 days after inoculation. In addition, the contents of JA-Ile, SA, ABA and IAA were determined by LC-MS.The results of two defense-related hormones showed that jasmonic acid content decreased significantly, while jasmonic acid content did not change significantly. In order to understand the difference in gene expression of potatoes infected by Aso, the 24 hpi, 36 hpi and 48 hpi transcriptome were determined. The results showed that the gene annotation and cluster analysis of DEGs revealed a variety of defense responses to Aso infection, especially the plant hormone signal transduction pathway. The differential expression of 10 DEGs was confirmed by qPCR analysis. Finally, through weighted gene co-expression network analysis (WGCNA), “samonl” was determined as a key hormone-related network in the process of Aso infection in potatoes. This study provides an important clue for understanding the interaction between potato and Aso and for disease resistance breeding.

Antifungal activities of plant-beneficial Bacillus have been widely studied in recent years. Numerous studies have studied the antifungal mechanisms of soluble non-volatile bioactive compounds such as lipopeptides and proteins produced by Bacillus against soil-borne diseases. However, the antagonistic mechanisms of volatile organic compounds (VOCs) from Bacillus against airborne phytopathogens are still largely unknown, and the function of Alternaria solani pathogenic genes has not been well identified. Here, we first isolated a Bacillus strain with strong antifungal activity and finally identified it as B. subtilis ZD01. Then, the antagonistic mechanisms of VOCs produced by strain ZD01, against A. solani, an airborne fungal pathogen that can cause early blight diseases of potato, were studied. We showed that VOCs produced by strain ZD01 can reduce the colony size and mycelial penetration and can cause serious morphological changes of A. solani. Scanning electron microscope (SEM) observation showed that VOCs released by ZD01 could cause more flaccid and gapped hyphae of A. solani. Also, we found that VOCs produced by ZD01 can inhibit the conidia germination and reduce the lesion areas and number of A. solani in vivo significantly. Meanwhile, based on gas chromatography/mass spectrometry (GC/MS) analysis, 29 volatile compounds produced by strain ZD01 were identified. Out of 29 identified VOCs, 9 VOCs showed complete growth inhibition activities against A. solani. Moreover, we identified two virulence-associated genes (slt2 and sod) in A. solani. slt2 is a key gene that regulates the mycelial growth, penetration, sporulation, and virulence in vivo in A. solani. In addition, sod plays a significant role in the SOD synthetic pathway in A. solani. Results from qRT-PCR showed that the transcriptional expression of these two genes was down-regulated after being treated by VOCs produced by ZD01. These results are useful for a better understanding of the biocontrol mechanism of Bacillus and offer a potential method for potato early blight disease control.

Plant rhizosphere-associated bacterial communities play key roles in affecting host health in response to diverse biotic stresses. Currently, the effect of continuous cropping of potato on soil bacterial communities and physiochemical parameters has not been well documented. Herein, we compared bacterial composition and diversity in rotationally and continuously (5, 10, and 30 years) cropped soils, and clarified the correlations between soil properties and the bacterial communities revealed by Illumina MiSeq sequencing. Our results demonstrated that Proteobacteria, Actinobacteria and Firmicutes were the predominant phyla in all the tested soil samples. While the abundance of Proteobacteria showed an increase, the abundance of Actinobacteria and Firmicutes displayed a reduction with the increase of continuous cropping years. At the genus level, as continuous cropping years increasing, the abundance of Pseudarthrobacter, Bacillus and Pseudomonas decreased, but the abundance of Rhodanobacte, Sphingobium, Mizugakiibacter and Devosia increased. Our results also demonstrated that the abundance of plant growth-promoting rhizobacteria in the rotationally cropped soil was significantly higher than that of continuously cropped soil. Furthermore, our results showed that soil organic matter, available nitrogen, available phosphorus and available potassium were significantly correlated with bacterial community distribution. Overall, our work provides a comprehensive view of altered structure and composition of bacterial communities between the continuously cropped soil and rotationally cropped soil.

Zhongyuan Tang, Weiwei Feng, Yiqing Yang, Qun Wang Department of Obstetrics & Gynecology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of ChinaCorrespondence: Weiwei FengDepartment of Obstetrics & Gynecology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, No. 197, Ruijin Er Road, Shanghai 200025, People’s Republic of ChinaTel +86 21 64370045Email fww12066@rjh.com.cnBackground: Ovarian cancer is the third leading cause of death among gynecological cancers in women in China. Chemotherapy is an important method for comprehensive treatment of ovarian cancer, but the curative effect is poor.Purpose: In this study, gemcitabine (GEM) -loaded RGD modified liposomes (LPs) were developed by the emulsification-solvent evaporation method and evaluated for their antitumor activity in vitro and in vivo.Methods: The physicochemical properties of LPs such as particle size, zeta potential and in vitro drug release were investigated. We also demonstrated the effect of RGD-GEM-PEG LPs in ovarian cancer.Results: RGD-PEG3500-DSPE GEM LPs had a uniform spherical morphology. The mean particle size and polydispersity index were determined to be 106.7 nm and 0.13 respectively. The ER% and DL% of the formulation were 79.6±3.1% and 6.1±1.4% respectively. Compared with the free drug, RGD modified GEM LPs had sustained-release properties in vitro. In vivo, compared with the DiD-RGD-PEG3500-DSPE GEM LPs group, free DiD-GEM and DiD-GEM LPs had no obvious fluorescence intensity in tumor of mice at all times, indicating that ordinary liposomes and drugs had no tumor targeting function. RGD-PEG3500-DSPE GEM LPs showed a superior antiproliferative effect on SKOV3 cells and had a better antitumor effect in vivo than non-modified LPs.Conclusion: These results indicated that RGD-PEG3500-DSPE GEM LPs were a promising candidate for antitumor drug delivery.Keywords: RGD, gemcitabine, liposomes, sustained-release, antitumor

In order to realize the fault diagnosis of planetary gear box, a fault diagnosis system based on Labview is designed. The design scheme of fault diagnosis system is put forward, and the typical fault mechanism and diagnosis principle of planetary gear are revealed. The virtual instrument system is designed. The experimental platform is established to simulate the broken teeth fault of solar gear. The envelope analysis of vibration data is carried out by the developed system. The results show that the system can accurately identify the characteristic frequency of the planetary gear fault and diagnose the fault, which proves that the system is effective and reliable.

Alternaria solani, the causal agent of early blight, is a major threat to global potato production. In recent years, Bacillus species have been widely used for biological control of a wide range of plant pathogens. However, limited knowledge is about the antifungal mechanisms of Bacillus strains against A. solani. Further, the specific antifungal activities of different types of secondary metabolites produced by Bacillus species have not been evaluated comprehensively. In this study, we isolated a Bacillus strain with strong antifungal activity and identified it as B. velezensis C16. The antagonistic mechanisms of non-volatile lipopeptides (LPs) and volatile organic compounds (VOCs) produced by strain C16 against A. solani were studied. The results indicated that LPs and VOCs showed considerable antagonistic activities to A. solani, with reduced colony diameter and significantly inhibited conidia germination. Hyphae treated with antagonistic compounds from C16 exhibited serious structural destruction, with thin or gapped structures and swollen sacs. Active compounds in culture supernatant and volatiles produced by C16 significantly reduced the lesion areas and growth of A. solani in vivo. High-performance liquid chromatography-mass spectrometry (HPLC-MS) and gas chromatography-mass spectrometry (GC-MS) analysis revealed iturins and volatile compounds of C16 that exhibit strong antagonistic activity on mycelia. This study comprehensively investigated the antifungal effects of LPs and VOCs released by strain C16 on the air-borne pathogen A. solani. The results suggest that these compounds exhibit a synergistic effect to resist early blight in potato.

Waste tires can be used as a substitute for coal due to the high calorific value. In this study, the co-pyrolysis characteristics of the waste tires (truck tires, liners and nylon tires), pulverized coal and their blends are studied using thermogravimetric analyzer. The pyrolysis of truck tires, liners and coal is characterized by a three stages reaction while the pyrolysis of nylon tires and their blends are four stages. The pyrolysis characteristics of the blends can be expressed by the superposition of the pyrolysis characteristics of the one-component material, indicating the slight interaction of the co-pyrolysis between the waste tire and the coal. The co-pyrolysis kinetics of waste tires, coal and their blends are also investigated. For the blends of coal with truck tires and liners, the increased content of coal reduces the activation energy in the 2nd stage and leads to an increase and then a decrease in the 3rd stage. Different from the former, the activation energy increases with the increase of tire powder in both the 2nd and 3rd stages in the blends of coal and nylon tires. This is attributed to the fact that the nylon tires contain more synthetic rubber than truck tires and liners.