神经元在动物下丘脑中分布的研究进展

对近年来研究较多的神经元在动物下丘脑各个神经核中的分布情况作了介绍,指出神经元在下丘脑各个神经核均有分布,甚至有几种神经元同时分布在某些神经核中,视上核(SON)、室旁核(PVN)及弓状核(ARC)是多种神经元集中分布的主要神经核,为进一步研究下丘脑的生理功能提供了形态学资料。     

海棠秋季二次开花的特点及原因探析

针对2007年秋季廊坊市重瓣粉海棠二次开花的特点进行了详细描述,并对其原因进行了初步探讨。     

草莓白绢病的病原鉴定及生物学特性

在实验室条件下对病原菌的形态特征、致病性和生物学特性进行了初步的研究。结果表明，引起草莓白绢病的病原物是齐整小核菌Sclerotium rol fsii Sacc．；病菌在偏酸性环境下生长较好，菌丝最适生长pH为5．08，在所测试的碳源中，S．rolfsii Sacc．对淀粉的利用最好，对乳糖利用效果最差；在供试氮源中，对硝酸钙和硝酸钠的利用最好，对尿素的利用最差；菌丝致死温度为50℃10min，菌核萌发的抑制温度为55℃10min。室内PDA平板药剂筛选结果表明，10％世高对病原菌菌丝生长的抑制效果最好。     

牛肉变质过程中微生物区系变化研究

微生物是引起牛肉变质的主要因素。未包装肉在 4℃条件下冷藏 7d后变质 ,表面带菌量达 3.3× 10 8个·cm-2 ,内部为 6 .8× 10 7个·g-1。保藏过程中微生物区系变化表现为革兰氏阴性杆菌上升 ,革兰氏阳性球菌下降 ,革兰氏阳性杆菌基本不变 ,变质时菌系变得简单。普通真空包装在 4℃条件下保存 3周后带菌量内外分别为 1.7× 10 7个·cm-2 和 1.8× 10 7个·g-1。在保藏过程中革兰氏阳性杆菌比例上升 ,革兰氏阴性杆菌上升不显著 ,革兰氏阳性球菌比例下降     

关于提高种植业效益的思考

总结了影响安庆市种植业效益提高主要因素,并提出了具体措施.     

新型肝癌介入治疗药物90Y-P204-Lipiodol的制备及其稳定性研究

目的:研究了新型肝癌介入治疗药物90Y-P204-Lipiodol的制备方法及其稳定性,旨在为肝癌的介入性内照射放疗提供满意的放射性药物。方法:采用传统化学工艺中比较成熟的萃取技术与核医学中的放射性核素标记方法相结合,以碘油(Lipiodol)作为萃取过程中的有机相,同时碘油也是被标记核素的载体,选择萃取剂P204作为碘油标记的偶联剂,利用萃取剂的萃取性能,在一定的pH、温度、搅拌时间和搅拌频率等条件下,对钇-90(90Y)进行萃取标记,测定萃取率,然后按不同的相比加入到生理盐水、新生小牛血清以及人的血液中,于液闪仪上测定被标记90Y的损失率。结果:0.01 mol/L的P204碘化油溶液萃取率高达99.9%,符合放射性核素标记的要求。本萃取法碘油标记后形成的络合物90Y-P204-Lipiodol并不改变碘化油的结构,而且具有很好的稳定性。结论:借助现代医学影像技术尤其是实时超声显像引导精确定位技术,有望通过瘤区注射方法使90Y-P204-Lipiodol稳定积聚在肝肿瘤组织内,从而实现真正意义上的肝癌内照射放疗,未来的研究将促进其在肝癌介入性内照射放疗中的早日应用。     

Growth and photosynthetic characteristics of blueberry (Vaccinium corymbosum cv. Bluecrop) under various shade levels

Blueberry can readily be shaded as a bush type plant, maybe affecting its growth and photosynthesis. Growth and photosynthetic characteristics of ‘Bluecrop’ blueberry grown under various shade levels were investigated to understand acclimation under shade conditions and to determine the optimal light conditions for agricultural purpose. Shade decreased the number of shoots per shrub, but increased shoot length. However, shade did not affect the number of leaves on the main axis. With increasing shade level, leaf length, width and area increased, but leaf thickness decreased. However, there was no obvious tendency in leaf length/width ratio with increasing shade level. Shade leaves had less dense stomata than sun leaves, but stoma was bigger in shade leaves than in sun leaves. With increasing shade level, non-photochemical quenching in blueberry leaves increased and the values were higher at low photosynthetic photon flux densities (PPFDs) in shade leaves than in sun leaves, resulting in the decreases in quantum yield, electron transport rate and net CO₂ assimilation rate (A_n). The maximum A_n at 31, 60, 73 and 83% shade levels was 11.8, 11.0, 8.4 and 7.5 μmol m⁻² s⁻¹, respectively. Following the slight decrease up to 100 μmol m⁻² s⁻¹ PPFD, stomatal conductance (g_s) linearly increased up to 600 μmol m⁻² s⁻¹ PPFD and became saturated at all shade levels. The leaves of the shrubs grown under the 83% shade level had a significantly lower g_s as compared to the leaves of the shrubs grown under the 31, 60 and 73% shade levels. Transpiration rate (E) linearly increased up to 600 μmol m⁻² s⁻¹ PPFD and was saturated at the 73 and 83% shade levels. However, E increased linearly at both 31 and 60% shade levels with increasing PPFD. The reproductive growth characteristics such as number of flowers, fruit set rate per flower bud and fruit yield also significantly decreased with increasing shade level. For agricultural purpose, therefore, shade level above approximately 60% of full sunlight must be avoided for optimal photosynthesis and growth of the ‘Bluecrop’ blueberry.     

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.     

复式断面明渠分析解应用研究

复式断面明渠中,二次流对水流特性具有重要的影响.现有复式断面横向速度分布的分析解模型中,对二次流的表示有多种形式.针对其中两种常用的考虑二次流影响的分析解模型在梯形明渠中的应用,采用FCF(Flood Channel Facility)的实验数据对模型进行了检验,结果表明两种模型各有利弊,具体应用中需根据实际情况进行选...     

高酸值米糠油酶法酯化脱酸研究

对脂肪酶Novozym 435催化高酸值米糠油酯化脱酸进行了研究.利用响应面分析法(RSM)优化脱酸条件.根据Box-Benhnken中心组合试验设计原理对试验条件进行优化,在分析各因素显著性及其交互作用的基础上,得出米糠油酯化脱酸最佳工艺参数为:酶质量分数1.1％、甘油添加量0.42 mg、温度56.4℃、反应时间23.2 h.实际测得脱酸后米糠油酸值(KOH)由56 mg/g降为5.04 mg/g,游离脂肪酸酯化率达到91％,与模型预测值基本相符.