植酸酶在畜牧业上的研究与应用

大量研究结果显示,植酸酶在动物生产和环境保护方面具有很好的应用前景。本文就植酸酶的种类和来源、理化特性、作用机理以及在畜牧业上的应用作一简要综述。     

Prostaglandin E2 receptors,EP2 and EP4, regulate expression of surface molecules and cytokines in B-cells of collagen-induced arthritic mice

AIM: To observe the immunoregulatory effects of prostaglandin E₂ receptor (EP) subtypes EP2/EP4 on the B-cells of collagen-induced arthritic(CIA)mice. METHODS: DBA/1 mice were immunized with chicken type II collagen emulsified in Freunds complete adjuvant to induce arthritis. B-cells were isolated from the splenocyte suspension by positive selection using anti-CD19 monoclonal antibody immunomagnetic beads. The expression of MHC II, CD 80 and CD86 was examined by flow cytometry. The mRNA levels of EPs, interferon γ (IFN-γ), tumor necrosis factor α (TNF-α), IL-6, IL-4, IL-10 and transforming growth factor-β (TGF-β) were detected by real-time RT-PCR. RESULTS: The rank of the mRNA levels of EPs was EP2>EP1>EP3>EP4 in B-cells and EP2/EP4 mRNA expression was obviously increased in CIA mice. EP2 antagonists inhibited the expression of MHC II, CD80 and CD86. EP4 antagonist had little effect on CD80. EP2/EP4 antagonists inhibited the mRNA expression of IFN-γ, TNF-α, and IL-6 (P<0.05 or P<0.01) and increased the expression of IL-10 (P<0.01 or P<0.05). Furthermore, the antagonists of EP2 and EP4 also increased the mRNA expression of IL-4 and TGF-β (P<0.01), respectively. CONCLUSION: PGE₂ modulate the pathogenesis of CIA via EP2/EP4 by regulating the expression of surface molecules and cytokines in B-cells. EP2/EP4 may be a new therapeutic target for treating rheumatoid arthritis.     

Effect of 3 isoforms of Ikaros on proliferation of human ovarian cancer SKOV3 cells

AIM: To investigate the effect of Ikaros isoforms on the proliferation of human ovarian cancer SKOV3 cells. METHODS: Three isoforms of Ikaros, IK1, IK2 and IK6, were transfected into ovarian cancer SKOV3 cells. CCK-8 assay and cell counting were used to detect the effects of Ikaros isoforms on the proliferation of SKOV3 cells. The cell cycle was analyzed by flow cytometry. The cell cycle-related proteins were detected by Western blot. RESULTS: IK1 and IK2 expression inhibited SKOV3 cells proliferation. Flow cytometry analysis indicated that IK1 and IK2 induced SKOV3 cell cycle arrest at the G₁ phase. IK6 isoform exerted no obvious effect on the proliferation or cell cycle of SKOV3 cells. Compared with control EV group, IK1 group and IK2 group showed a dramatic elevation in the expression of the cell cycle inhibitor p21, along with a substantial decrease in the expression of the cell cycle inducers cyclin D1 and cyclin D2, which did not change in IK6 group. CONCLUSION: IK1 and IK2 significantly inhibit the proliferation of ovarian cancer SKOV3 cells and induce cell cycle arrest at G₁ phase by regulation of cell cycle-related proteins cyclin D1, cyclin D2 and p21, while IK6 isoform exerts no obvious effect on the proliferation and cell cycle of SKOV3 cells.     

Sodium dichloroacetate improves radiosensitivity of U251 cells

AIM: To study the change of radiosensitivity of U251 cells after treated with sodium dichloroacetate (DCA) and further to explore the possible mechanism.METHODS: The U251 cells were divided into 4 groups: control group, DCA group, X-ray irradiation without DCA pretreatment (IR) group and X-ray irradiation with DCA pretreatment (DIR) group. MTT assay was applied to determine the cell viability. The intracellular reactive oxygen species (ROS) were detected by DHE fluorescence. The expression level of Bcl-2 was assessed by Western blot. The percentage of apoptosis of cells was determined by flow cytometry. RESULTS: No difference between control group and DCA group in cell viability (P>0.05) was observed. However, the cell viability of both IR group and DIR group was markedly reduced compared with control group (P<0.05). Furthermore, the viability of DIR group was significantly decreased compared with IR group (P<0.05). The percentage of ROS positive cells was obviously increased in DIR group compared with IR group (P<0.05). The expression level of Bcl-2 was sharply decreased in DIR group (P<0.05) and the percentage of apoptosis of cells was significantly elevated (P<0.05) in DIR group compared with IR group.CONCLUSION: The better antitumor effect was obtained by improving the radiosensitivity through pretreating the cells with DCA, and the possible mechanism was down-regulation of the Bcl-2 expression by developing the intracellular ROS.     

1％阿维·鱼藤新型乳油防治柑橘红蜘蛛田间药效试验

采用1％阿维·鱼藤新型乳油对柑橘红蜘蛛进行田间药效试验。结果表明,1％阿维·鱼藤新型乳油500、1000和1500倍液3个处理对活动螨态均具优异的杀灭效果,药后1d,500倍液处理组防效显著高于对照药剂200阿维·哒3000倍液处理,二者各为99．70%±0．30％和93．64%±2.29％;药后5d,1％阿维·鱼藤新型乳油500、1000和1500倍液3个处理对活动螨态的防效与对照药剂相当,4者防效均高达94．72％以上。此外,1％阿维·鱼藤新型乳油1500、1000和500倍3个处理均对柑橘红蜘蛛螨卵具一定的杀卵效果,其中500倍处理组的杀卵作用较好,校正杀卵率达80．59%±2．51％。     

南京周边地区古砂砾层土壤和岩石形成的数学分析

Research samples were taken from an ancient gravel stratum which is not only a representative soil layer along the middle-lower reaches of the Yangtze River in East China ,but also one of the primary Neozoic strata in Nanjing district.Located mostly on the second and third terraces,the ancient gravel strata formed the geomorphic landscapes of terrace and step.They were complex in constitution,varied widely in stability,of multiple sources,locally derived ,and associated with braided streams in the deposition environment ,A CIPW(Cross,Iddings,Pirsson and Washington) method modified by the author was used to analyze the soil-rock-forming materials of finer grains(less than 2 mm in size) of the ancient gravel stratum.Results of the analysis showed that the sandy grains were composed of apatite,ilmenite,potassium feldspar,plagioclase,enstatite and free quartz,the clay mainly of kaolinite,and the cement of a combination of silicon,aluminum and iron at a ratiof of 46:44:10.In the soil-rock-forming processes, including compactional solidifiation,water-stable illuviation-cementation,homogneous overgrowth and so on,the loose soil-rock-forming components gradually changed into consolidated soil and further to the early stage of lithification.Meanvwhile,from ,the analysis,we found that the ancient gravel stratum had been protected by overlying Xiashu loess or basalt and the overloading resulted in overconsolidated strata ,The modified CIPW method was applicale and effective for semi-quantitative analysis.     

生殖细胞早期发生与减数分裂启动调节机制的研究进展

卵巢性生殖疾病发生的主要原因之一是卵子发生过程中减数分裂发生或染色体分离异常。为了更好地进行这些生殖疾病的诊断和治疗,需要充分地了解个体发育的生物学过程中及关键时间点。鉴于此,本文主要阐述了哺乳动物生殖细胞早期发生和减数分裂启动的生理过程,介绍生殖细胞的出现、迁移、性别分化和减数分裂的整个过程。深入了解卵母细胞发生过程将为利用体外发育来源的卵母细胞治疗卵巢性生殖疾病,克服女性不孕、卵巢早衰等重大疾病提供一定的理论支持。     

玉米田杂草马唐的生长特性研究

在田间和室内条件下研究了马唐的生长特性。结果表明 ,马唐种子具有短期休眠 ,其出苗的适宜土壤深度为 0 .5～ 4 .0cm ;随着密度的增加和出苗时间的推迟 ,马唐的单株生长量逐渐下降。     

Overview on current criteria for heavy metals and its hint for the revision of soil environmental quality standards in China

Following rapid social and economic development over the past several decades, soil pollution by heavy metals (HMs) has been both serious and widespread in China. The Soil Environmental Quality Standards (SEQSs) in China (GB 15618-1995) have been introduced to encourage and enforce sustainable soil HM management. However, in recent years, HM contents in soils have frequently been found to exceed their associated standard values, while the crops growing on them might still meet regulatory standards, and vice versa. There is thus growing awareness that GB 15618-1995 does not effectively regulate current soil HM pollution, as it has encountered bottlenecks, and disappointing outcomes caused by poor execution along with deficiencies and gaps in the policies. However, due to the deficiency of scientific research about relationships between soil HM concentrations and their ecological or human health effects, the development of SEQSs in China is still greatly restricted. This paper discusses international SEQSs of HMs as well their development in China over time, then examines current Chinese SEQSs to demonstrate their potential regulatory deficiencies by referring to international SEQSs. The corresponding legislative policies are described, and scientific information or responses are outlined for maintaining soil environmental quality. China's experience has shown that policy and science can be linked to work in tandem to better understand and manage soil quality issues.     

探讨图书馆的桌面系统部署

针对目前图书馆桌面系统部署工作存在的耗时长、强度大、效率低的缺．最,采用Ghost和SnapDeploy等软件,通过创建和恢复映像的方法,实现操作系统和应用软件的快速、批量和集中部署,并阐述了桌面系统部署的原则以及在管理方面应注意的几个方面.