A study of the interaction between inverted cucurbit[6]uril and symmetric viologens

The interaction between inverted cucuribit[6]uril (iQ[6]) and a series of symmetric viologens bearing aliphatic substituents, namely dicationic dialkyl-4,4′-bipyridinium guests where the alkyl substituent is CH3(CH2)n (n = 1, 3 and 5) or benzyl, has been studied in aqueous solution by 1H NMR spectroscopy, electronic absorption spectroscopy, Isothermal Titration Calorimetry and mass spectrometry. The viologen bearing C6H5CH2 substituents has also been investigated. In the case of the dialkyl-derived guests, single crystal X-ray diffraction, on crystals grown in the presence of CdCl2, revealed the compositions to be 2(C36H36N24O12), 4(C14H18N2),Cd5Br9.56Cl10.442(H2O).2(H3O); 2(C36H36N24O12),C18H26N2,2(CdCl4),36H2O and 2(C36H36N24O12),2(C11H17N),2(CdCl4),20H2O for the use of n = 1, 3 or 5 respectively. Thus, in the solid state, in the case of both BV2+ (n = 3) and HV2+ (n = 5), an interaction of viologen with iQ[6] was observed and the structure adopted is an external ‘dumbbell-type’ structure

Screening and Degradation Characteristics of a Fumonisin B1-Degrading Fungal Strain

A fungal strain capable of degrading fumonisin B1 (FB1) from ground maize samples heavily contaminated with fumonisin was obtained by enrichment culture method. The strain was named as FDS-2, and was characterized for its growth and degradation characteristics, and the initial degradation pathway of FB1 by FDS-2 was investigated. The strain was identified as Exophiala spinifera according to its culture characteristics, microscopic characteristics and phylogenetic tree based on RNA-internal transcribed spacer (ITS) sequence characteristics. The optimum growth and degradation conditions were 30 ℃ and pH 5.0. Under these conditions, the strain could completely degrade 250 μg of FB1 within 48 h. Intracellular FB1-degrading enzymes were discovered in this strain. Using liquid chromatography-mass spectrometry (LC-MS) to analyze the degradation products, it was determined that the primary degradation pathway began with the degradation of FB1 into hydrolyzed FB1. This study provides a strain resource and a theoretical basis for the biodegradation of fumonisin in grain and feed

Numerical Study on Soft Coal Pillar Stability in an Island Longwall Panel

Roadway support and management of longwall panels in an island soft coal panel are always difficult work. In a test mine, stress distribution, deformation characteristic, and plastic zone distribution around the roadway and coal pillars in the development and mining periods were investigated with respect to the widths of different coal pillars using theoretical and simulation methods. The most reasonable width of coal pillars was comprehensively determined, and the field test was conducted successfully. The results show that a reasonable width of coal pillars is 7.0–8.2 m using the analytical method. The distribution of vertical stress in the coal pillars showed an asymmetric “double-hump” shape, in which the range of abutment pressure was about 26.0–43.0 m, and the roadway should be laid away from stress concentration. When the coal pillar width is 5.0–7.0 m, deformation of the roadway is half that with 8.0–10.0 m coal pillar in the development and mining period. The plastic zone in the surrounding rock firstly decreases and increases with increasing coal pillar width; the smallest range occurs with a coal pillar width of 5.0 m. Finally, a reasonable width for coal pillars in an island panel was determined to be 5.0 m. Industrial practice indicated that a coal pillar width of 5.0 m efficiently controlled deformation of the surrounding rock, which was an important basis for choosing the width of coal pillars around gob-side entries in island longwall panels with similar geological conditions

Can the Integration of Rural Industries Help Strengthen China’s Agricultural Economic Resilience?

Rural industrial integration is the key to promoting the development of rural industrial restructuring and modernization, and plays a vital role in improving agricultural economic resilience. Based on the evaluation index system of agricultural economic resilience and the level of rural industrial integration development, respectively, this paper uses panel data from 30 provincial administrative regions in China from 2000 to 2020 to empirically test the impact of rural industrial integration development on agricultural economic resilience by using an individual fixed-effects model and a mediating-effects model. The results show that rural industrial integration significantly contributes to enhancing agricultural economic resilience, and the conclusion still holds after a series of robustness tests. There is dimensional and regional heterogeneity in the impact of rural industrial integration on agricultural economic resilience, and the strength of the promotion effect by dimension is in the order of adaptive adjustment capacity, transformation and innovation capacity, and resilience to recovery capacity. In the eastern and central regions, the promotion effect of rural industrial integration on agricultural economic resilience is more significant. In the main food-producing areas, the promotion effect of rural industrial integration on resilience to recovery is significantly slighter than that of non-food-producing regions. Mechanism analysis indicates that regional industrial structure optimization is an essential channel for rural industrial integration to enhance the resilience of the agricultural economy. On this basis, in order to strengthen agricultural economic resilience, provinces should actively explore differentiated industrial integration policies to enhance industrial structure optimization and upgrading, stimulate agricultural economic vitality, and foster the development of China’s agricultural modernization

Genetic variations of IL-12B, IL-12Rβ1, IL-12Rβ2 in Behcet's disease and VKH syndrome.

PURPOSE: To investigate the associations of single nucleotide polymorphisms (SNPs) of three genes (IL-12B, IL-12Rβ1 and IL-12Rβ2) in Behcet's disease (BD) and Vogt-Koyanagi-Harada (VKH) syndrome in a Chinese Han population. METHODS: A total of 806 BD cases, 820 VKH patients, and 1600 healthy controls were involved in this study. The first investigation included 400 BD patients, 400 VKH cases, and 600 healthy individuals. A second confirmatory study included a separate set of 406 BD patients, 420 VKH cases and another 1000 normal controls. Genotyping was carried out by PCR-restriction fragment length polymorphism assay and results were validated by using direct sequencing. The χ2 test was performed to compare the allele and genotype frequencies between cases and healthy controls. RESULTS: This study comprised two phases. In the first phase study, a significantly increased frequency of the rs3212227/IL-12B genotype CC and C allele was found in BD patients as compared to controls (Bonferroni corrected p value (pc) = 0.009, OR 1.8; pc = 0.024, OR 1.3, respectively). Moreover, the frequency of the C allele of rs3212227/IL-12B was also significantly increased in VKH patients (pc = 0.012, OR 1.3, 95% CI 1.1 to 1.6). No associations were found for the other seven tested SNPs either in BD or VKH disease. The second study as well as the combined data confirmed the significant association of rs3212227/IL-12B with BD (CC genotype: combined pc = 6.3×10(-7), OR = 1.8; C allele: combined pc = 2.0×10(-5), OR = 1.3, respectively) and the C allele frequency of rs3212227/IL-12B as the risk factor to VKH patients (combined pc = 2.5×10(-5), OR 1.3, 95% CI 1.2 to 1.5). CONCLUSIONS: Our study revealed that the IL-12B gene is involved both in the susceptibility to BD as well as VKH syndrome