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71.
苗雪梅  冯周琴 《蛇志》1995,7(3):4-6
采用青龙胶丸治疗脑梗塞后慢性脑功能不全50例。结果表明,在连续治疗3个月后,慢性脑功能不全所致的头痛、头晕、失眠、生活主动性减退、对周围事物反应能力减退等症状的有效率均达80%以上。神经心理学检查证实其对指向记忆、联想学习、人像特点联想回忆、认识能力等均有较好的改善作用。治疗前后血液流变学指标的改善,提示青龙胶丸降低纤维蛋白原、降低血液粘度,具有抗凝、解聚、溶栓、扩张血管、改善微循环的作用。认为是其对慢性脑功能不全发挥较好治疗作用的药理基础之一。  相似文献   
72.
本文论证了菲波纳斯(Fibonacci)级数与菊花花冠结构的关系,发现了花冠的通用数学模式:花冠(数目)=(5×倍数)十F_n(F_(n-1)+F_(n-2))  相似文献   
73.
汉防己甲素(汉甲)及克矽平(Polyvinylpyridine-N-Oxide,PVNO)是目前较为有效的抑制矽肺纤维化的药物。本文研究了其对胶原mRNA水平的影响.斑点杂交实验表明大鼠接尘60天和120天后α1(Ⅰ)及α1(Ⅲ)mRNA水平明显上升,经汉甲或克矽平治疗1个月或3个月后,胶原mRNA水平明显下降。原位杂交结果表明胶原mR-NA银颗粒与细胞性结节和增厚的肺泡壁的成纤维细胞分布重合。汉甲或克矽平治疗后银颗粒数下降。提示汉甲及克矽平对矽肺进程中的胶原基因表达增强有抑制作用。  相似文献   
74.
Abstract. In order to explore whether seed size affects plant response to elevated CO2, plants grown from red oak (Quercus rubra L.) acorns were studied for differences in their first year response to CO2 concentrations of 350 and 700 μl/l. Overall, at final harvest, total biomass of plants grown in elevated CO2 were 47 % larger than that of plants grown in ambient CO2. There were significant interactions between CO2 treatments and initial acorn mass for total biomass, as well as for root, leaf, and stem biomass. Although total biomass increased with increasing initial acorn mass for both high and ambient CO2 plants, high CO2 plants exhibited a greater increase than ambient CO2 plants, as indicated by a steeper slope in high CO2 plants. However, CO2 levels did not affect biomass partitioning traits, such as root/shoot ratio, leaf, stem, and root weight ratios, and leaf area ratio. These results suggest that variation in seed size or initial plant size can cause intraspecific variation in response to elevated CO2.  相似文献   
75.
几种细胞分裂素诱导石竹外植体直接再分化成花芽的机理   总被引:4,自引:0,他引:4  
用MS+2,4-D0.1mg/L为基本培养基,分别附加不同浓度的ZT、BA和KT,对石竹的叶片、茎和花等外植体直接再分化成花芽的试验表明:叶片的外植体在有BA时可再分化出只有红色花瓣的不正常花芽;在含ZT的培养基中再分化出具有1~2片叶或无叶的花芽,其花有两性花,雌花和仅单个雌蕊的不正常花,两性花可发育成结籽的果实;KT未能诱导花芽分化。茎外植体,3种CTK都不能诱导出花芽。花等外植体仅在KT3mg/L的培养中再分化出无叶的不正常花芽,ZT和BA的处理均不能诱导出花芽。  相似文献   
76.
An earlier experiment with the pink lady's slipper orchid demonstrated that plant leaf area was lowered only after successive years of increased fruit production. This result suggested that the cost of reproduction was small in relation to the energy budget of the plant. To test this idea, plants were subjected to experimental hand-pollination treatments to increase fruit set as well as leaf removal treatments to decrease the energy budget of plants. Changes in plant size in years 2 and 3 and, to some extent, rate of flowering, were determined by a combination of initial plant size, leaf removal treatments in year 1, fruit production in year 1, and damage from an unplanned fire in year 2. Plants that had both leaves removed and produced a fruit in 1987 decreased in size in the following 2 years in comparison with other treatment groups. The cost of fruit production was not apparent in plants that had only one or no leaves removed. Plants apparently have to be put into severe physiological stress in order for a cost of reproduction to appear in the following year. The cost of producing one fruit was a decline of plant size in the following year of 30 cm2, which is very similar to our previous experiment using a different design. An additional experiment failed to find evidence that these plants increase their photosynthetic rate to compensate for the loss of leaves or the cost of maturing fruit. Published experiments in both the greenhouse and the field that failed to find a cost of reproduction should be reevaluated in terms of the intensity of treatment imposed and the overall energy budget of the plant in field situations.  相似文献   
77.
G S Yi  B S Choi    H Kim 《Biophysical journal》1994,66(5):1604-1611
The structure of a chemically synthesized 25-residue-long functional signal peptide of Escherichia coli ribose binding protein was compared with that of a nonfunctional mutant-signal peptide using circular dichroism and two-dimensional 1H NMR in solvents mimicking the amphiphilic environments. The functional peptide forms an 18-residue-long alpha-helix starting from the NH2-terminal region and reaching to the hydrophobic stretch in a solvent consisting of 10% dimethylsulfoxide, 40% water, and 50% trifluoroethanol (v/v). The nonfunctional mutant peptide, which contains a Pro at position 9 instead of a Leu in the wild-type peptide, does not have any secondary structure in that solvent but forms a 12-residue-long alpha-helix within the hydrophobic stretch in water/trifluoroethanol (50:50, v/v) solvent. It seems that the Pro-9 residue in the nonfunctional peptide disturbs the helix propagation from the hydrophobic stretch to the NH2-terminal region. Because both of these peptides have stable helices within the hydrophobic stretch, it may be concluded that the additional 2 turns of the alpha-helix in the NH2-terminal region of the wild-type signal peptide is important for its function.  相似文献   
78.
The infectivities of Steinernema carpocapsae, S. glaseri, S. scapterisci, and Heterorhabditis bacteriophora to Japanese beetle larvae, Popillia japonica, and house cricket adults, Acheta domesticus, were compared using external exposure and hemocoelic injection. Only H. bacteriophora and S. glaseri caused high P. japonica mortality after external exposure. When nematodes were injected, P. japonica had a strong encapsulation and melanization response to all species except S. glaseri. Heterorhabditis bacteriophora and S. carpocapsae were able to overcome the immune response, but S. scapterisci was not. All species except S. scapterisci were able to kill and reproduce within the host. Only S. scapterisci and S. carpocapsae caused A. domesticus mortality after external exposure. When nematodes were injected, A. domesticus had a strong immune response to all species except S. scapterisci. Steinernema carpocapsae effectively overcame the strong immune response and caused high host mortality, but S. glaseri and H. bacteriophora did not. Steinernema scapterisci caused high host mortality and reproduced, S. glaseri and H. bacteriophora caused low host mortality but only S. glaseri reproduced, and S. carpocapsae was able to kill the host but reproduced poorly. Most (ca. 90%) of the S. carpocapsae in the hemocoel of P. japonica became encapsulated and melanized within 8 hours postinjection. The symbiotic bacterium, Xenorhabduf nematophilus, was often released before this encapsulation and melanization.  相似文献   
79.
河南叶县下寒武统辛集组单板类和腹足类化石的研究   总被引:8,自引:3,他引:5  
本文描述和讨论了河南叶县杨寺庄下寒武统辛集组单板类13种,腹足类2种,未定类1种。其中包括2新属6新种:Repenoconus xinjiensis gen.nov.,Scenella pycna sp.nov.,Securiconus vulgaris sp.nov.,Obtusocnus grossicostus sp.nov.,Igorellina proboscis sp.nov.,Gal  相似文献   
80.
作者在武陵山地区的鱼类寄生线虫调查工作中,发现一种毛细线虫,经研究,为一新种,定名为岁新毛细线虫,新种(Neocapillariaphoxinisp.nov.)。根据其特征,为此建立一新属──新毛细线虫属。  相似文献   
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