The swamp eel, Monopterus albus, is an important aquaculture species in Asia (mainly China) whose production has seriously suffered from infectious diseases. In spite of the critical requirement for aquaculture practices, to date there is scant information on its immune defence. Here, the genetic characteristics of Toll-like receptor 9 (TLR9), which plays crucial roles in the initiation of host defence against microbial invasion, were analysed. It exhibits a striking lack of genetic variation resulting from a recent demographic bottleneck. A comparison with the homologue of M. javanensis revealed that replacement but not silent differences have nonrandomly accumulated in the coding sequences at the early stage following their split from a common ancestor. Furthermore, the replacements relevant to the type II functional divergence have mainly occurred in structural motifs mediating ligand recognition and receptor homodimerization. These results provide hints to understand the diversity-based strategy of TLR9 in the arms race against pathogens. Furthermore, the findings reported here give credence to the importance of basic immunology knowledge, especially for the key elements, in genetic engineering and breeding for disease resistance in the eel and other fishes.

Spermidine is a class of biologically active organic small molecules that play an important role in maintaining intestinal homeostasis. The specific objective of this study was to explore the effects of spermidine on intestinal morphology, metabolites, and microbial diversity in mice. We showed that 0.3 mmol/L of spermidine significantly promoted the growth of ileal villi (p < 0.05), and 3.0 mmol/L of spermidine significantly increased the body weight of mice and promoted the growth of jejunum villi (p < 0.05). The 16S rDNA sequencing results indicated that 3.0 mmol/L of spermidine affected the balance of the intestinal flora by increasing the abundance of intestinal Lactic acid bacteria and reducing the abundance of harmful bacteria (Turicibacter and Alistipes). Additionally, spermidine affects the levels of microbial metabolites such as succinic acid and Pantetheine. In summary, spermidine affects intestinal morphology and regulates intestinal flora and metabolites, and this study has provided a new understanding of spermidine's effects on the intestinal tract.

A balanced, diverse gut microbiota is vital for animal health. The microbial population is shaped by multiple factors including genetic background and environment, but other determinants remain controversial. Numerous studies suggest that the dominant factor is genetic background while others emphasize the environmental factors. Here, we bred asexual hybridization queens (AHQs) of honeybees through nutritional crossbreeding (laid in Apis mellifera colony but bred in Apis cerana colony), sequenced their gut microbiome, and compared it with normally bred sister queens to determine the primary factor shaping the gut microbiota. Our results showed that the dominant genera in the gut microbiota of AHQs were Brevundimonas, Bombella, and Lactobacillus, and its microbial community was more related to A. mellifera queens. The AHQs had a moderate number of different bacterial species and diversity, but total bacterial numbers were low. There were more significant taxa identified in the comparison between AHQ and A. cerana queen according to LEfSe analysis results. The only genetic-specific taxon we figured out was Brevundimonas. The growth of core bacterial abundance showed different characteristics among different queen groups in the first week after emerging. Collectively, this study suggested that the genetic background played a more dominant role than environmental factors in shaping the gut microbiota of honeybee queen and the microbiota of midgut was more sensitive than that of rectum to this impact.

采用密度泛函理论对单重态势能面上的二氯卡宾1CCl2与臭氧1O3反应的微观机理进行了研究.在B3LYP/6-311G(d,p)水平上全参数优化反应物、中间体、过渡态和产物的几何构型,同时使用内禀反应坐标(IRC)在同一水平上对过渡态与中间体之间的联系进行了确认,并且在QCISD/6-311G(d,p)水平上计算了各驻点的单点能.研究得到1CCl2与1O3反应的8种产物通道,即P1 (Cl2CO+1O2)、P2(CO2+ClClO)、P3(CO3+Cl2)、P4(CO+ ClOOCl)、P5(CO2+ClOCl)、P6(v-CO2 +ClOCl)、P7(ClCClO+1O2)和P8 (COO+ ClOGl),其中通道P1(Cl2CO+1O2)是最主要的产物通道,通道P2 (CO2+ClClO)、P3(CO3 +Cl2)、P4(CO+ ClOOCl)对反应体系的产物贡献依次减小,而通道P5(CO2+ ClOCl)、P6 (v-CO2 +ClOGl)、P7(ClCClO+1O2)和P8(COO+ClOCl)很难生成.

A detailed singlet potential energy surface survey on the 1CF2 + 3O2 reaction is carried out in order to clarify the reaction mechanisms of the singlet difluorocarbene (1CF2) with oxygen (3O2) at the B3LYP/6-311++G(d,p) level. To determine the accurate energies of all stationary points, the QCISD/6-311++G(d,p) single-point calculations are done by using the B3LYP/6-311++G(d,p) optimized geometric structures. The title reaction is important in high temperature processes. Four product channels, P1(F2 + CO2), P2(F2O + CO), P3(2F + CO2) and P4(FCO + FO), have been found in the 1CF2 + 3O2 reaction. P1(F2 + CO2) and P3(2F + CO2) have comparable contributions to the title reaction and they are more favorable than the other two thermodynamically and kinetically.

A detailed singlet potential energy surface survey on the (CF2)-C-1 + O-3(2) reaction is carried out in order to clarify the reaction mechanisms of the singlet difluorocarbene ((CF2)-C-1) with oxygen (O-3(2)) at the B3LYP/6-311++G(d,p) level. To determine the accurate energies of all stationary points, the QCISD/6-311++G(d,p) single-point calculations are done by using the B3LYP/6-311++G(d,p) optimized geometric structures. The title reaction is important in high temperature processes. Four product channels, P-1(F-2 + CO2), P-2(F2O + CO), P-3(2F + CO2) and P-4(FCO + FO), have been found in the (CF2)-C-1 + O-3(2) reaction. P-1(F-2 + CO2) and P-3(2F + CO2) have comparable contributions to the title reaction and they are more favorable than the other two thermodynamically and kinetically.

A series of Co–Cu composite oxides with different Co/Cu atomic ratios were prepared by a co-precipitation method. XRD, N2 sorption, TEM, XPS, H2-TPR, CO-TPR, CO-TPD and O2-TPD were used to characterize the structure and redox properties of the composite oxides. Only spinel structure of Co3O4 phase was confirmed for the Co–Cu composite oxides with Co/Cu ratios of 4/1 and 2/1, but the particle sizes of these composite oxides decreased evidently compared with Co3O4. These composite oxides could be reduced at lower temperatures than Co3O4 by either H2 or CO. CO and O2 adsorption amounts over the composite oxides were significantly higher than those over Co3O4. These results indicated a strong interaction between cobalt and copper species in the composite samples, possibly suggesting the formation of Cu x Co3−x O4 solid solution. For the preferential oxidation of CO in a H2-rich stream, the Co–Cu composite oxides (Co/Cu = 4/1–1/1) showed distinctly higher catalytic activities than both Co3O4 and CuO, and the formation of Cu x Co3−x O4 solid solution was proposed to contribute to the high catalytic activity of the composite catalysts. The Co–Cu composite oxide was found to exhibit higher catalytic activity than several other Co3O4-based binary oxides including Co–Ce, Co–Ni, Co–Fe and Co–Zn oxides.

The unsupported Co3O4 catalyst showed excellent low temperature CO oxidation activity.Its application for carbon monoxide preferential oxidation has attracted a great attention since it exhibited a potential prospect for industrial application.In this report,Co3O4 nanoparticles with two different kinds of morphologies were prepared by liquid-precipitation air-oxidation pyrolysis method.In order to investigate the impact of preparation conditions(such as precipitating agents,aging time and calcination temperature) on the morphology and crystal size of Co3O4 nanoparticles,we used XRD,SEM to characterize the prepared Co3O4.Morphologies of Co3O4 are consistent with the morphology of their precipitation precursors.The higher the calcination temperature was,the larger the crystal size became.Catalytic preferential oxidation of carbon monoxide over Co3O4 nanoparticles in H2-rich gas was performed.We compared the catalytic performance of Co3O4 synthesized by above methods,found that size and surface area of the catalyst had correlation with its catalytic activity.The Co3O4 obtained by urea-precipitation air-oxidation method calcination at 250～300℃ exhibits the best activity.

Objective To observe the effects of Ardisia gigantifolia Stapf extract on blood clotting system and hemorrheology and its mechanism.Methods The model of thrombus was induced by 0.01%AD stimulation and PT,TT,APTT,Fg,blood viscosity and blood physiologic.Results Compared with 0.9%NaCl control group,pathological model control group could significantly shorten PT and APTT(P0.05),increase the content of Fg and blood low shearing rate(6 r/min and 12 r/min)viscosity(P0.01,P0.05);Compared with pathological model control group,high dose groups could significantly prolong PT,TT and APTT(P0.05),significantly decrease the content of Fg and blood high middle low shearing rate(6,12 r/min and 30 r/min) viscosity(P0.01,P0.05).Conclusion Ardisia gigantifolia Stapf extract can prolong PT,TT,and APTT,and also decrease blood viscosity and the content of Fg,furtherly affected intrinsic and extrinsic coagulation system to prevent from thrombosis.