副结核分枝杆菌MAP1588C蛋白的原核表达与抗原性分析

从副结核分支杆菌K-10菌株基因组中扩增出516 bp的MAP1588C基因片段,插入原核表达载体pET-28b(+),转化至大肠杆菌BL21(DE3),在0.5 mmol/L的IPTG诱导下进行表达;利用融合蛋白的组氨酸标签进行亲和层析纯化重组蛋白;通过抗6 His标签抗体的Western blot验证了纯化蛋白产物;另外,副结核阳性牛血清可检测到该蛋白条带。结果表明,表达的重组蛋白MAP1588C的蛋白分子量为21 kDa,具有良好抗原性,有望将此抗原用于建立副结核的ELISA诊断方法。     

冰温结合气调及保鲜剂技术在肉制品保鲜中的应用

阐述了冰温、气调及保鲜剂3种保鲜方法的原理及研究现状,并根据各自的优缺点,提出在冷鲜肉的保鲜中综合运用冰温 气调 保鲜剂的技术路线.对于大多数食品,冰温处理的货架期是普通冷藏的1.5～4.0倍.O250% CO250%或O270% CO230%的气调包装可以维持猪肉的色泽在一个理想的感官水平.用复合保鲜剂处理宰后的猪肉能有效地抑制大肠杆菌的生长繁殖、控制细菌总数的增殖、减缓TVB-N值的上升,从而延长鲜肉保质期.在猪肉宰后使用保鲜剂抑菌,运输和销售过程中使用冰温加气调能有效延长肉制品的货架期.     

let-7a inhibits MAP4K3/MKK4/JNK signaling pathway to decrease neuronal apoptosis in rats with intracerebral hemorrhage

AIM To investigate the effect of microRNA let-7a on neuronal apoptosis in a rat model of intracerebral hemorrhage (ICH). METHODS Forty-eight healthy SD rats were selected, 8 of which served as sham group, and 2 μL of type VII collagenase was injected into globus pallidus of the remaining rats to construct ICH model. These ICH rats were randomly divided into model (2 μL normal saline) group, let-7a agomir group, NC agomir group, let-7a antagomir group and NC antagomir group, with 8 rats in each group, and the corresponding drugs were injected into the lateral ventricle. After 7 d, the neurological function scoring was performed, and HE staining was used to observe the pathological damage. RT-qPCR and Western blot were used to detect the expression of related proteins. TUNEL staining was used to detect neuronal apoptosis. The targeting relationship between let-7a and mitogen-activated protein kinase kinase kinase kinase 3 （MAP4K3） was predicted by bioinfomatic software, and further verified by dual-luciferase reporter assay. RESULTS In animal experiments, when let-7a was over-expressed, neurological function scores were reduced,and the pathological damage was alleviated. Glial fibrillary acidic protein (GFAP) expression was down-regulated, neuronal apoptosis was reduced, and the protein levels of cleaved caspase-3 and cleaved PARP were decreased (P<0.05). In cell assays, MAP4K3 was one of the target genes of let-7a, and MAP4K3 was negatively regulated by let-7a. let-7a over-expression inhibited the expression of MAP4K3/MKK4/JNK. CONCLUSION let-7a reduces neuronal apoptosis in ICH rats by inhibiting the MAP4K3/MKK4/JNK signaling pathway.     

Study of signal transduction factors involved in mycoparasitic response of Trichoderma atroviride

Numerous Trichoderma spp. are mycoparasites and commercially applied as biological control agents against a large number of plant pathogenic fungi. The mycoparasitic interaction is host-specific and several research strategies have been applied to identify the main genes and compounds involved in the antagonist-plant-pathogen three-way interaction. During mycoparasitism, signals from the host fungus are recognised by Trichoderma, stimulating antifungal activities that are accompanied by mo…     

Mycosporine-Like Amino Acids Promote Wound Healing through Focal Adhesion Kinase (FAK) and Mitogen-Activated Protein Kinases (MAP Kinases) Signaling Pathway in Keratinocytes

Mycosporine-like amino acids (MAAs) are secondary metabolites found in diverse marine, freshwater, and terrestrial organisms. Evidence suggests that MAAs have several beneficial effects on skin homeostasis such as protection against UV radiation and reactive oxygen species (ROS). In addition, MAAs are also involved in the modulation of skin fibroblasts proliferation. However, the regulatory function of MAAs on wound repair in human skin is not yet clearly elucidated. To investigate the roles of MAAs on the wound healing process in human keratinocytes, three MAAs, Shinorine (SH), Mycosporine-glycine (M-Gly), and Porphyra (P334) were purified from Chlamydomonas hedlyei and Porphyra yezoensis. We found that SH, M-Gly, and P334 have significant effects on the wound healing process in human keratinocytes and these effects were mediated by activation of focal adhesion kinases (FAK), extracellular signal-regulated kinases (ERK), and c-Jun N-terminal kinases (JNK). These results suggest that MAAs accelerate wound repair by activating the FAK-MAPK signaling pathways. This study also indicates that MAAs can act as a new wound healing agent and further suggests that MAAs might be a novel biomaterial for wound healing therapies.     

Study on precipitation of struvite and struvite-K crystal in goats during onset of urolithiasis

To learn more about the biomineralization process of struvite in ruminants, a seldom noticeable crystal, struvite-K, was investigated in six goats in which urolithiasis was induced by feeding a cottonseed meal and rice straw diet supplemented with MgO. The compositions of crystals and calculi were studied by chemical qualitative analysis and X-ray energy dispersive spectrometry (EDS). The activity product (AP) and relative supersaturation (RSS) of magnesium ammonium phosphate (MAP) and potassium magnesium phosphate (MKP) were calculated to compare the difference of crystals formed in this process. The results showed that calculi consisted of MAP with a little MKP. Crystals in the urine consisted of MAP and MKP before stone formation, but crystals in urine after stone formation mainly consisted of MKP. The AP and RSS of MAP and MKP significantly decreased after stone formation. It was concluded that MAP and MKP may coexist in the crystals of urine before struvite calculi formation but MKP did not precipitate to struvite calculi and was separated out as crystal sedimentation of urine. The changes of crystallization of MAP and MKP contributed partially to the supersaturation status of MAP and MKP during struvite stone formation.     

果蔬呼吸反应动力学研究进展及其在MAP保鲜中的应用

低氧和高二氧化碳环境可以延长果蔬的货架期,在MAP系统中果蔬的呼吸作用和气体通过包装薄膜进行交换维持果蔬的微环境气体组成而使果蔬的货架期延长在果蔬的MAP系统设计中,果蔬的呼吸速率模型是成功的关键本文综述了果蔬呼吸速率动力学研究的实验方法、果蔬的MAP数学模型及其在保鲜中的一些应用.     

Modified atmosphere packaging of fresh produce with a biodegradable laminate of chitosan-cellulose and polycaprolactone

Use of a biodegradable laminate of a chitosan-cellulose and polycaprolactone as a film for modified atmosphere packaging (MAP) of fresh produce was tested. The temperature dependence of O₂, CO₂ and N₂ gas permeability coefficients for the biodegradable laminate was examined. The coefficients increased linearly with increasing temperature in the range 10–25 °C. The coefficients were validated by experiments on MAP with shredded lettuce and shredded cabbage. MAP systems with head lettuce, cut broccoli, whole broccoli, tomatoes, sweet corn and blueberries were designed using the gas permeability coefficients. The gas composition in each biodegradable package including the fresh produce was simulated to be close to the optimal composition. The biodegradable laminate was found suitable as a packaging material for storage of fresh produce.     

Variations on conserved signaling pathways in biocontrol and development:G protein and MAPK genes of Trichoderma. atroviride and T. virens

Filamentous fungi employ conserved eukaryotic signaling pathway to detect and respond to environmental signals, including the presence of the host. Genetic experiment in which a particular signaling protein is lost, or its activity enhanced, have defined some of the function of heterotrimeric G proteins and MAP kinases in development and virulence. A hallmark of these studies is that orthologs in different species may have different functions. Antagonistic fungal-fungal interactions form …