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121.
浙江金华北山植物区系地理的研究   总被引:16,自引:1,他引:15  
金华北山约有种子植物140科、519属、1052种。区系成分中,以北温带、泛热带、东亚三种成分为主,植物区系具明显的亚热带性质。以植物地理成分为指标,对金华山与全国其它14个山地的植物区系进行了模糊聚类分析。结果表明,庐山、天目山植物区系与浙南一闽北的九龙山、武夷山植物区系之间无明显的分界线。  相似文献   
122.
动物群落是构成城市绿地生态系统的关键要素,声景作为野生动物重要的生态信息,掌握其时空变化及其影响因素,对于指导城市绿地景观设计与生物多样性保护具有重要意义。本文以Web of Science数据库的核心合集2005–2022年收录的67篇研究文献为对象,综合梳理与分析了城市绿地动物声景的时空模式及其驱动因素。城市绿地动物声景在空间上表现出环境空间梯度和植被空间结构的差异,动物声音多样性随海拔、纬度、城市化程度的降低以及植被类型和高度的增加呈现升高趋势。时间尺度呈现出昼夜、季节和年度变化差异,表现为鸟类在黎明和黄昏合唱、昆虫和两栖动物在夜间鸣叫以及季节性和年度性发声规律等。影响城市动物声景模式的因素主要包括植被、环境、人为干扰和动物自身驱动等。动物声景作为当前声景生态学研究的热点之一,面临大时空尺度演变规律研究不足、动物声景分析有限等挑战,建议未来着重开展多时空尺度变化规律研究、创新动物声景分析方法、定量解析影响因素及其响应机制、建立全球动物声景数据库等。  相似文献   
123.
陈鹏  宋佳  郭璞  冀瑞卿 《菌物学报》2023,42(1):297-311
蜜环菌属Armillaria真菌具有较高的食药用价值。由于蜜环菌的生长发育过程较复杂,还未完全实现商业化栽培,野生资源的供应受到季节性和地域性的影响。本研究以采自东北地区蜜环菌属的3个菌株为研究对象,通过培养物的形态特征及分子标记确定菌株JG19016为奥氏蜜环菌A. ostoyae,菌株JG19017为高卢蜜环菌A. gallica,菌株JG19018为中国蜜环菌生物种C。奥氏蜜环菌JG19016最适生长温度为25 ℃,高卢蜜环菌JG19017的最适生长温度为22 ℃,中国蜜环菌生物种C JG19018则在22-25 ℃时菌丝生长速度最快;3个菌株最适pH为5-6。奥氏蜜环菌JG19016对葡萄糖和蔗糖利用率较好,高卢蜜环菌JG19017对葡萄糖利用率较好,中国蜜环菌生物种C JG19018对葡萄糖和淀粉利用率较好;蛋白胨对3个菌株促进作用最强,为最适氮源。培养基中加入VB1,对3个菌株的菌丝生长均有明显的促进作用。奥氏蜜环菌JG19016菌丝生长的最优培养基配方为:葡萄糖20 g,蛋白胨3 g,磷酸二氢钾2 g,硫酸镁1.5 g,VB1 10 mg,琼脂20 g,水1 L。在木屑基质中培养,其配方的最优碳氮比为38:1,最佳木屑粗细比为3:1以上。出菇条件探索结果显示,菌丝及菌索长满菌袋(17 mm×33 mm×5 mm丝聚乙烯袋)需要50-60 d,之后在18 ℃、60%湿度和12 h散射光的环境中,10 d左右可观察到原基产生。增加菇房湿度到90%-95%,2-3 d可观察到1-3 cm的幼子实体,7 d左右菌柄和菌盖完全分化,10 d左右观察到菌盖展开。  相似文献   
124.
为了解珍稀濒危植物细果秤锤树(Sinojackia microcarpa)开花特征和有性繁殖,对其花部形态特征、开花动态、花粉胚珠比(P/O)、柱头可授性、花粉活力、套袋试验、访花昆虫及访花频率进行观测。结果表明:(1)细果秤锤树的杂交指数(OCI)为4,单花期5~7 d,种群花期可持续20 d左右。花粉与胚珠比为4 093.21±498.56。开花后第3天的花粉活力最高(76.21%),而开花后第7天时花粉活力较低(18.37%)。细果秤锤树柱头最适可授期在开花后第2天。(2)套袋试验表明,细果秤锤树存在部分自交不亲和性,同时不存在无融合生殖,传粉昆虫是其完成生殖过程所必需的,且异株授粉能够提高其坐果率和结籽率。细果秤锤树的访花昆虫有3目5科7种,主要访花昆虫有黄胸木蜂(Xylocopa appendiculata)、熊蜂(Bombus sp.)、胡蜂(Vespa sp.)、中华蜜蜂(Apis cerana)、黑带食蚜蝇(Episyrphus balteatus)、其中熊蜂平均访花频率最高,达(8.67±0.21) 次·h-1。对该物种开花生物学特征与繁育系统进行深入研究,有利于进一步探究其濒危机制,为后续珍稀濒危植物的研究提供理论依据和参考。  相似文献   
125.
摘要 目的:探讨高频重复经颅磁刺激(rTMS)联合Brunnstrom分期训练对脑卒中恢复期患者康复效果的影响。方法:根据随机数字表法将新疆医科大学第一附属医院2020年1月~2022年2月期间收治的脑卒中恢复期患者80例分为对照组(40例,Brunnstrom分期训练)和研究组(40例,高频rTMS联合Brunnstrom分期训练)。对比两组疗效、美国国立卫生研究院卒中量表(NIHSS)评分、功能独立性量表(FIM)评分、生活质量评分、血清神经因子指标[髓鞘碱性蛋白(MBP)、神经元特异性烯醇化酶(NSE)、神经生长因子-1(NGF-1)]。结果:研究组的临床总有效率(92.50%)明显高于对照组(70.00%)(P<0.05)。治疗4周后,研究组MBP、NSE低于对照组,NGF-1高于对照组(P<0.05)。与对照组比较,治疗4周后,研究组NIHSS评分降低,FIM评分升高(P<0.05)。治疗4周后,研究组心理/躯体/物质/社会功能评分较对照组高(P<0.05)。结论:高频rTMS联合Brunnstrom分期训练有助于提高脑卒中恢复期患者的康复效果,同时还可调节血清神经指标,提高生活质量。  相似文献   
126.
The content, composition and variation of vitamin compounds in goat milk have been little studied. An experimental design was based on 28 commercial farms, selected considering the main feeding system (based on main forage and especially pasture access), goat breed (Alpine vs Saanen) and reproductive management (seasonal reproduction), in the main French goat milk production area. Each farm received two visits (spring and autumn) that included a survey on milk production conditions and bulk milk sampling. Milk vitamins (A, E, B2, B6, B9, B12) and carotenoid concentrations plus colour indices were evaluated. A stepwise approach determined the variables of milk production conditions that significantly altered milk indicators. The main forage in the diet was the major factor altering goat milk vitamin and carotenoid concentrations and colour indices. Bulk milk from goats eating fresh grass as forage was richer in α-tocopherol (+64%), pyridoxal (+35%) and total vitamin B6 (+31%), and b* index (characterising milk yellowness in the CIELAB colour space) was also higher (+12%) than in milk from goats eating conserved forages. In milk from goats eating fresh grass, concentrations of pyridoxamine, lutein and total carotenoids were higher than in milk of goats fed corn silage (+24, +118 and +101%, respectively), and retinol and α-tocopherol concentrations were higher than in milk of goats fed partially dehydrated grass (+45 and +55%). Vitamin B2 concentration was higher in milk of goats eating fresh grass than in milk of goats fed hay or corn silage as forage (+10%). However, bulk milk when goats had access to fresh grass was significantly poorer in vitamin B12 than when fed corn silage (?46%) and in γ-tocopherol (?31%) than when fed conserved forage. Alpine goats produced milk with higher vitamin B2 and folate concentrations than Saanen goats (+18 and +14%, respectively). Additionally, the milk colour index that discriminates milks based on their yellow pigment contents was 7% higher in milk from Alpine than Saanen herds, but milk from Saanen goats was richer in lutein (+46%). Goat milks were richer in vitamins B2 and B12 and folates, but poorer in vitamin B6 in autumn than in spring (+12, +133, +15 and ?13%, respectively). This work highlights that goat milk vitamin and carotenoid concentrations and colour indices vary mainly according to the main forage of the diet and secondly according to the breed and season.  相似文献   
127.
Two types of serine proteases and a serine protease homologue cDNAs were isolated from Hyphantria cunea larvae induced immune response due to an injection of a microorganism through RT‐PCR and cDNA library screening, and their characteristics were examined. The isolated cDNAs are composed 2.1 kb, 2.2 kb, and 2.5 kb nucleotide each, which encoded 388, 390, 580 amino acid residues, and were designated as HcPE‐1, HcPE‐2 and HcPE‐3, respectively. They were revealed as serine proteases or a serine protease homologue with the clip domain through a database search. The deduced amino acid sequence comparison showed high homology of 72‐78% among them. Six Cys residues of the N‐terminal clip domain forming the disulfide bond, Cys residues of the catalytic domain, and Cys residues forming inter‐bridge between clip domain and catalytic domain were also well preserved. Three amino acid residues, His, Asp, and Ser, within the active site were perfectly conserved in HcPE‐2 and HcPE‐3, however, His was replaced with Gln178 in HcPE‐1. The Arg residues (HcPE‐1, Arg132; HcPE‐2, Arg134; HcPE‐3, Arg325) known as the activation sites by proteolytic cleavage were preserved well in all three types of protein. In case of HcPE‐3, three continuous clip‐like domains existed in the N terminal. As the result of phylogenetic analysis, three clip domain family of protein from H. cunea make groups with arthropod proclotting enzyme precursor. Northern blot analysis showed all three genes were induced through an injection of Escherichia coli, but expression patterns were varied.  相似文献   
128.
The C2 domain is a Ca(2+)-binding motif of approximately 130 residues in length originally identified in the Ca(2+)-dependent isoforms of protein kinase C. Single and multiple copies of C2 domains have been identified in a growing number of eukaryotic signalling proteins that interact with cellular membranes and mediate a broad array of critical intracellular processes, including membrane trafficking, the generation of lipid-second messengers, activation of GTPases, and the control of protein phosphorylation. As a group, C2 domains display the remarkable property of binding a variety of different ligands and substrates, including Ca2+, phospholipids, inositol polyphosphates, and intracellular proteins. Expanding this functional diversity is the fact that not all proteins containing C2 domains are regulated by Ca2+, suggesting that some C2 domains may play a purely structural role or may have lost the ability to bind Ca2+. The present review summarizes the information currently available regarding the structure and function of the C2 domain and provides a novel sequence alignment of 65 C2 domain primary structures. This alignment predicts that C2 domains form two distinct topological folds, illustrated by the recent crystal structures of C2 domains from synaptotagmin 1 and phosphoinositide-specific phospholipase C-delta 1, respectively. The alignment highlights residues that may be critical to the C2 domain fold or required for Ca2+ binding and regulation.  相似文献   
129.
Summary The growth factor receptor-bound protein-2 (Grb2) is an adaptor protein that mediates signal transduction pathways. Chemical shift assignments were obtained for the SH2 domain of Grb2 by heteronuclear NMR spectroscopy, employing the uniformly 13C-/15N-enriched protein as well as the protein containing selectively 15N-enriched amino acids. Using the Chemical Shift Index (CSI) method, the chemical shift indices of four nuclei, 1H, 13C, 13C and 13CO, were used to derive the secondary structure of the protein. Nuclear Overhauser enhancements (NOEs) were then employed to confirm the secondary structure. The CSI results were compared to the secondary structural elements predicted for the Grb2 SH2 domain from a sequence alignment [Lee et al. (1994) Structure, 2, 423–438]. The core structure of the SH2 domain contains an antiparallel -sheet and two -helices. In general, the secondary structural elements determined from the CSI method agree well with those predicted from the sequence alignment.Abbreviations crk viral p47gag-crk - EGF epidermal growth factor - GAP GTPase-activating protein - PI3K phosphatidylinositol-3-kinase - PLC- phospholipase-C-, shc, src homologous and collagen - src sarcoma family of nonreceptor tyrosine kinase  相似文献   
130.
五种高山藏医药用植物茎叶的结构特征研究   总被引:21,自引:5,他引:16  
通过对青藏高原东北部3800m至5100m处生长的五种高山藏医药用植物茎叶的解剖观察发现,这些植物的叶表皮单层,气孔不下陷,但叶肉中的栅栏细胞多层,有的叶表面密被表皮毛、角质膜厚,茎叶中普遍形成发达的通气组织。这些特征是高寒地区空气稀薄、气温低、日照辐射强等外界条件长期作用的结果。  相似文献   
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