Regeneration of Psychotria umbellata and production of the analgesic indole alkaloid umbellatine

Psychotria umbellata Vell. (Rubiaceae), a Brazilian coastal woody species, produces umbellatine (also known as psychollatine), an analgesic indole alkaloid. An in vitro embryogenic regeneration protocol capable of yielding alkaloid-accumulating plants was developed. Rhizogenic calli, which were obtained from stem segments derived from rooted apical cuttings, were cultured on Murashige and Skoog's (MS) medium containing either 1 mg l(-1) NAA (naphthalene acetic acid) and no kinetin, or 5 mg l(-1) NAA + 1 mg l(-1) kinetin. Calli did not accumulate umbellatine. Segments of rhizogenic callus were cultured on complete MS medium with various concentrations of kinetin and sucrose. Plant regeneration was best in the light with 0.25 mg l(-1) of kinetin and 1.5% sucrose. After 3 months of acclimatization in soil mixture, plant survival was 81%. Leaves of 10-month-old regenerated plants yielded umbellatine concentrations equivalent to those of adult forest-grown plants.     

进口原羊毛携带有害生物情况及检疫监管模式探讨

通过对进口原羊毛进行研究分析,认为其可携带许多种动物病原、植物有害生物、病原微生物、害虫、媒介生物以及粪便等,具有携带率高、隐蔽性强、难以预测等特点,会给我国动植物和人类健康造成威胁,也会给我国农畜产品的出口造成严重影响。针对当前检验检疫工作任务较重、人力不足、标准体系不完善、监管难度加大等方面的实际情况,提出需建立包括加工厂注册登记、开展风险分析和分类管理、现场查验、后续监管、提升能力和完善体系等内容的检疫监管模式。     

Intramammary infusion of an Enterococcus faecium SF68 preparation promoted the involution of drying off Holstein cows partly related to neutrophil‐associated matrix metalloproteinase 9

A problem for dairy cows following milk stasis is to cope with a high risk of intramammary infection and there is a need to initiate an extensive renewal of secretory modules in mammary glands so that milk production in next lactation may be optimized. We recently reported that ultrasonicated Enterococcus faecium SF68 (SF68) is compatible with cow mammary glands and an enhancer of innate immunity during the immediate post‐milk stasis period. The current study further examines the concomitant effect of ultrasonicated SF68 on mammary tissue remodeling. Four Holstein cows each received intramammary infusions of regular antibiotic dry‐cow formula (positive control) and two different doses of SF68 in different quarters. Analyses of individual quarter secretion samples showed faster neutrophil infiltration, earlier modifications in protein composition, including caseins and lactoferrins, as well as more prompt elevation of the specific unit of 92‐kDa matrix metalloproteinase 9 (MMP9) in SF68‐infused quarters compared to the positive controls. Intramammary infusion of ultrasonicated SF68 seems able to accelerate the regression of mammary synthetic capacity and potentiate the breakdown of glandular extracellular matrix, indicating a more efficient mammary gland involution. Correlation analyses imply that the ability of ultrasonicated SF68 to induce faster neutrophil chemotaxis and the associated MMP9 release is partly responsible.     

三种野生观赏蕨类植物的耐旱性研究

本文研究狗脊、盾蕨、凤丫蕨的耐旱能力,为其园林应用提供参考依据。对三种蕨类植物材料在温室中采用自然干旱的方式进行干旱胁迫,每5天测定1次胁迫过程中生理生化指标,并测定其叶片保水力。结果表明:干旱胁迫下,狗脊的叶片保水力变化幅度最大,凤丫蕨其次,盾蕨最小;各植物电导率与对照组相比,均持续上升;叶绿素的含量均下降,凤丫蕨叶绿素含量变化幅度最大;叶片中的SOD活性、POD活性、MDA含量、可溶性蛋白含量变化趋势均为先升后降,凤丫蕨SOD活性、POD活性、MDA含量在前期迅速增长,狗脊、盾蕨缓慢上升。综合分析表明三种蕨类耐旱能力依次为狗脊盾蕨凤丫蕨。     

Brazilian savanna re-establishment in a monoculture forest:diversity and environmental relations of native regenerating understory in Pinus caribaea Morelet. stands

In this paper we analyze and compare natural regeneration in shrub-tree community in three areas below Pinus caribaea stands and a natural area (cerrado sensu stricto). We also analyze the influence of...     

Effect of reforestation on annual water yield in a large watershed in northeast China

A simplified water balance model in conjunc-tion with an evapotranspiration (ET) model and cumulative forest cover data were used to quantify the changes in annual water yield in response to reforestat...     

食品微生物学课程中思政元素挖掘与解析

“食品微生物学”是一门综合性的学科,涉及到基础微生物学,食品微生物学,工业微生物学和医学微生物学等领域,知识涉及面广,课程综合性强,对人们的日常生活影响大。将食品微生物学打造成课程思政教育的前沿阵地尤为重要。因此,本文首先系统性的介绍了将专业课程与思政教育相结合的重要性和必要性。接着笔者重点对食品微生物学中所蕴含的思政元素进行了深入解析,将一些典型案例与课程中的知识点有机融合。最后从改革教学方法,创新教学理念和提高教师队伍的思政意识等方面来阐述了如何才能实现课程思政建设的高效性。本文能够为后续的专业课程如何进行思政建设提供参考,更重要的是能够为教师如何从专业课的知识点中挖掘思政元素提供借鉴和启发。     

Inhibition of tumorigenesis in ApcMin/+ mice by a combination of (-)-epigallocatechin-3-gallate and fish oil

The effect of a combination of (-)-epigallocatechin-3-gallate (EGCG) with fish oil on intestinal tumorigenesis in Apc (Min/+) mice fed a high-fat diet was investigated in the present study. The combined treatment of EGCG and fish oil for 9 weeks reduced the tumor number by 53% as compared to controls while neither agent alone had a significant effect. Apoptosis was significantly increased in all treatment groups. beta-Catenin nuclear positivity in adenomas from the combination group was lower than control mice, implicating the modulation of Wnt signaling by the combination. Fish oil and the combination significantly reduced prostaglandin E 2 (PGE 2) levels in small intestinal tumors as compared to controls, suggesting modulation of aberrant arachidonic acid metabolism by fish oil. Akt phosphorylation in adenomas was significantly reduced in all treatment groups, which may have contributed to the observed increase in apoptosis. The results indicate that a combination of low doses of EGCG and fish oil can inhibit tumor multiplicity in Apc (Min/+) mice.     

不同乳化剂对牛骨白汤稳定性的影响

【目的】探讨不同乳化剂对牛骨白汤的乳化效果,以促进牛骨白汤标准化、规模化生产。【方法】以牛骨素和牛油为主要原料制备牛骨白汤,以乳化度、粒径分布、表观黏度和流变行为作为评判依据,探究不同乳化剂(单硬脂酸甘油酯、丙二醇脂肪酸酯、Span80和阿拉伯胶)对牛骨白汤稳定性的影响,以乳化度为响应值进行响应面试验,同时建立数学模型并验证其可靠性。【结果】与未添加乳化剂组(空白组)相比,4种乳化剂的添加对牛骨白汤的乳化稳定性均有显著性影响(P<0.05)。最佳工艺条件为添加质量分数0.8%丙二醇、质量分数0.7%单甘酯以及质量分数0.8%阿拉伯胶,此时制备的牛骨白汤乳化度为0.92,乳化稳定性较好。【结论】确定了高稳定性、品质良好的牛骨白汤制备工艺,为畜禽骨工业化应用提供理论基础和参考依据。     

Characterization of culture supernatant proteins from Brucella abortus and its protection effects against murine brucellosis

In this study, we characterized the secreted proteins of Brucella abortus into the enriched media under the bacterial laboratory growth condition and investigated the pathogenic importance of culture supernatant (CS) proteins to B. abortus infection. CS proteins from stationary phase were concentrated and analyzed using 2D electrophoresis. In MALDI TOF/TOF analysis, more than 27 proteins including CuZn SOD, Dps, Tat, OMPs, Adh, LivF, Tuf, SucC, GroEL and DnaK were identified. Cytotoxic effects of CS proteins were found to increase in a dose-dependent manner in RAW 264.7 cells. Upon B. abortus challenge into phagocytes, however, CS proteins pre-treated cells exhibited lower bacterial uptake and intracellular replication compared to untreated cells. Immunization with CS proteins induced a strong humoral and cell mediated immune responses and exhibited significant higher degree of protection against virulence of B. abortus infection compared to mice immunized with Brucella broth protein (BBP). Taken together, these results indicate that B. abortus secreted a number of soluble immunogenic proteins under laboratory culture condition, which can promote antibody production resulted in enhancing host defense against to subsequently bacterial infection. Moreover, further analysis of CS proteins may help to understand the pathogenic mechanism of B. abortus infection and host–pathogen interaction.