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1.
短期旱作促进水稻种子根的伸长。利用cDNA—AFLP技术分析种子根根尖在旱作条件下差异表达的基因,同时比较这些基因在种子根尖、侧根和不定根原基区的表达差异。在1640个片段中,70个在种子根根尖中受旱作诱导,其中24个被克隆并测序。2个基因分别编码丙酮酸脱氢酶激酶(PDK)和腺嘌吟转磷酸核糖基酶(APRT),并用电子拼接技术获得水稻的APRT全长cDNA;另一个经cDNA末端快速扩增法延长后仍无同源序列。Northern杂交验证了这3个基因的cDNA—AFLP表达谱。这是首次报告使用cDNA—AFLP技术研究水稻根组织的差异表达基因。  相似文献
2.
A distinct role for norepinephrine in memory retrieval   总被引:9,自引:0,他引:9  
Murchison CF  Zhang XY  Zhang WP  Ouyang M  Lee A  Thomas SA 《Cell》2004,117(1):131-143
A role for norepinephrine in learning and memory has been elusive and controversial. A longstanding hypothesis states that the adrenergic nervous system mediates enhanced memory consolidation of emotional events. We tested this hypothesis in several learning tasks using mutant mice conditionally lacking norepinephrine and epinephrine, as well as control mice and rats treated with adrenergic receptor agonists and antagonists. We find that adrenergic signaling is critical for the retrieval of intermediate-term contextual and spatial memories, but is not necessary for the retrieval or consolidation of emotional memories in general. The role of norepinephrine in retrieval requires signaling through the beta(1)-adrenergic receptor in the hippocampus. The results demonstrate that mechanisms of memory retrieval can vary over time and can be different from those required for acquisition or consolidation. These findings may be relevant to symptoms in several neuropsychiatric disorders as well as the treatment of cardiac failure with beta blockers.  相似文献
3.
五种食用菌氨基酸含量的测定及营养评价   总被引:7,自引:0,他引:7  
研究测定了五种食用菌中氨基酸的含量,并利用五种非生物学指标对蛋白质的营养价值进行评价。五种食用菌氨基酸种类齐全,必需氨基酸占氨基酸总鼍的百分比分别达到45.94%、37.62%、42.45%、41.54%、35.98%。茶树菇和姬松茸的限制性氨基酸为半胱氨酸和甲硫氨酸,鸡腿菇、香菇和黑木耳的限制性氨基酸是缬氨酸。不同的评价指标对蛋白质进行营养评价,评价结果会有所差异。  相似文献
4.
Cysteinyl leukotrienes are involved in ischemic brain injury, and their receptors (CysLT(1) and CysLT(2)) have been cloned. To clarify which subtype mediates the ischemic neuronal injury, we performed permanent transfection to increase CysLT(1) and CysLT(2) receptor expressions in PC12 cells. Oxygen glucose deprivation (OGD)-induced cell death was detected by Hoechst 33258 and propidium iodide fluorescent staining as well as by flow cytometry. OGD induced late phase apoptosis mainly and necrosis minimally. Over-expression of CysLT(1) receptor decreased and over-expression of CysLT(2) receptor increased OGD-induced cell death. An agonist LTD(4) (10(-7)M) also induced apoptosis, especially in CysLT(2) receptor over-expressing cells. A selective CysLT(1) receptor antagonist montelukast did not affect OGD-induced apoptosis; while non-selective CysLT receptor antagonist Bay u9773 inhibited OGD-induced apoptosis, especially in CysLT(2) receptor over-expressing cells. Thus, CysLT(1) and CysLT(2) receptors play distinct roles in OGD-induced PC12 cell death; CysLT(1) attenuates while CysLT(2) facilitates the cell death.  相似文献
5.
Zhou Y  Wei EQ  Fang SH  Chu LS  Wang ML  Zhang WP  Yu GL  Ye YL  Lin SC  Chen Z 《Life sciences》2006,79(17):1645-1656
The role of 5-lipoxygenase (5-LOX) in brain injury after cerebral ischemia has been reported; however, the spatio-temporal properties of 5-LOX expression and the enzymatic activation are unclear. To determine these properties, we observed post-ischemic 5-LOX changes from 3 h to 14 days after reperfusion in rats with transient focal cerebral ischemia induced by 30 min of middle cerebral artery occlusion. We found that the expression of 5-LOX, both mRNA and protein, was increased in the ischemic core 12-24 h after reperfusion, and in the boundary zone adjacent to the ischemic core 7-14 days after reperfusion. The increased 5-LOX was primarily localized in the neurons in the ischemic core at 24 h, but in the proliferated astrocytes in the boundary zone 14 days after reperfusion. As 5-LOX metabolites, the level of cysteinyl-leukotrienes in the ischemic brain was substantially increased 3 h to 24 h, near control at 3 days, and moderately increased again 7 days after reperfusion; whereas the level of LTB(4) was increased mildly 3 h but substantially 7-14 days after reperfusion. Thus, we conclude that 5-LOX expression and the enzymatic activity are increased after focal cerebral ischemia, and spatio-temporally involved in neuron injury in the acute phase and astrocyte proliferation in the late phase.  相似文献
6.
5-Lipoxygenase (5-LOX) is the enzyme metabolizing arachidonic acid to produce pro-inflammatory leukotrienes. We have reported that 5-LOX is translocated to the nuclear envelope after ischemic-like injury in PC12 cells. In the present study, we determined whether 5-LOX is activated (translocation and production of leukotrienes) after oxygen-glucose deprivation (OGD) in primary rat cortical neurons; if so, whether this activation is mediated by NMDA receptor. After OGD, 5-LOX was translocated to the nuclear envelope as detected by immunoblotting, immunostaining and green fluorescent protein-5-LOX transfection. 5-LOX metabolites, cysteinyl-leukotrienes (CysLTs) but not leukotriene B4, in the culture media were increased 0.5-1.5 h after recovery. Similarly, NMDA (100 microm) also induced 5-LOX translocation, and increased the production of CysLTs during 0.5-1 h NMDA exposure. Both OGD and NMDA reduced neuron viability. NMDA receptor antagonist MK-801 inhibited almost all the responses to OGD and NMDA; whereas 5-LOX activating protein inhibitor MK-886 and 5-LOX inhibitor caffeic acid inhibited the reduction of neuron viability and the production of CysLTs, but did not affect 5-LOX translocation. From these results, we conclude that OGD can activate 5-LOX in primary rat cortical neurons, and that this activation may be partly mediated via activating NMDA receptor.  相似文献
7.
太原地区某些植物净化二氧化硫潜力的研究   总被引:4,自引:0,他引:4       下载免费PDF全文
 本文以研究某些树木和农作物(以下简称植物)对SO2的净化潜力来评价太原地区大气环境容量中的生物净化参数。内容包括三部分:植物年生物量的调查;用人工模拟熏气试验测定植物吸收SO2的强度和吸收转运周期;以及该地区植物净化SO2潜力的估算。太原地区树木叶片的年生物量约18万吨.树叶平均吸收SO2的强度为1.9%。SO2在树叶中的吸收转运周期约30天。树叶旺盛生活期约90天,相当于三个周期.由此计算可得本地区树木叶片每年吸收SO2的总量约一万吨。郊区农作物年生物量总计为25万吨.农作物吸收SO2的强度为0.45%.SO2吸收转运周期为20天。作物旺盛生活期为40天,相当于两个周期。计算得出本地区农作物吸收 SO2的总量约两千余吨。把树木和农作物年吸收SO2量之和,作为全年植物净化SO2的总量,约1.2万吨。在所研究的525平方公里范围内,平均每平方公里内的植物每年净化SO2的最大潜力约为24吨。在加强污染源治理和控制排放的前提下,利用植物净化大气S02是一条经济、简便和有效的补充措施。  相似文献
8.
不同供水条件下水稻幼苗根系形成的遗传分析   总被引:1,自引:0,他引:1  
张卫萍  吴平 《Acta Botanica Sinica》2001,43(10):1024-1030
利用分子标记图谱对溶液培养与旱作培养(纸培养)下的水稻(Oryza sativa L.)幼苗的种子根与最长不定根长,不定根数,总根干重,根冠比等性状进行了基因定位与遗传分析。4种参数共检测到6个数量性状位点(quantitative trait loci,QTLs)与22对上位性互作位点,其中溶液培养中的最长不定根长,总根干重和旱作培养中的总根干重检测到的QTLs位点对总变异的贡献率分别为20%,23%和13%左右;旱作培养中的最长不定根长,不定根数,根冠比和溶液培养中的根冠比仅检测到上位性位点,对表型变异的贡献率在12%-61%之间,溶液培养与旱作条件下没有一个或一对检测到的QTL或互作位点完全相同,提示溶液培养和旱作条件下影响幼苗根系生长的遗传机制差异,上位性作用对旱作培养条件下的根生长具重要影响。  相似文献
9.
极端污染环境下草苷膦抗性菌株HTG7的筛选及其特性研究   总被引:1,自引:0,他引:1  
从被草苷膦极度污染的土壤中分离到一株极端抗草苷膦菌HTG7,经初步鉴定其为可变盐单胞菌(Halomonas varabilis),该菌株最高可以耐受500mmol/L左右的草苷膦浓度。电镜观察表明,550mmol/L的草苷膦浓度下,细胞大量坏死。生理生化特性表明该菌最适pH为7.0,并且在氯化钠浓度0~10%生长良好。  相似文献
10.
兔肾积水模型的建立及SPECT和CT灌注成像   总被引:1,自引:1,他引:0  
韩文文  张潍平  彭芸  杨洋  温洋  张祺丰  杨吉刚 《中国实验动物学报》2009,17(6):410-414,F0002,I0001
目的探索建立肾盂输尿管连接部梗阻所致肾积水的动物模型的可行性;探讨CT灌注成像对积水肾脏肾功能的评估价值。方法10周龄雄性新西兰兔50只随机分组,假手术组20只,分离左侧输尿管后直接关腹。模型组30只,选用腰大肌包埋输尿管造成左侧肾盂输尿管连接部梗阻。术前两组进行单光子发射计算机体层成像(SPECT)比较左肾功能,检验无差异后在术后3月分别行左肾SPECT、CT灌注,以病理检查为佐证,观察两组参数变化,进行CT灌注各项参数和GFR的统计学相关性分析。结果模型组建模成功达70%,呈慢性肾积水病理表现,左肾皮髓质CT灌注参数BF、BV、PS均下降,与相应GFR呈高度正相关。结论腰大肌包埋输尿管的模型制作方法具有可行性。CT灌注参数可作为肾功能状态的评定指标,具有一定的临床指导意义。  相似文献
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