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51.
de Wolf  Hein 《Hydrobiologia》1993,269(1):1-9
The history of diatom research in The Netherlands and Flanders is summarized in this report. A. van Leeuwenhoek observed diatoms as early as 1702. The first inventories were made in The Netherlands by R. B. van den Bosch (1846) and in Flanders by J.-J. Kickx (1867). Diatoms were already used in geological research in the second half of the nineteenth century. The Synopsis by H. van Heurck (1880–1885) enabled many twentieth century workers to do applied research for geological and ecological purposes.  相似文献   
52.
 本文引用Harper(1977)的构件结构理论,从构件结构单位、无性系分株和无性系三个层次,对四川南充市郊慈竹无性系种群的能值特点及其影响能值的计测因素进行了定量研究。研究结果表明:慈竹无性系种群中,各构件单位的去灰分热值(AFCV)分别为:根15349.42J/g、根茎16372.92J/g、秆17106.06J/g、枝18111.99J/g和叶19451.90J/g;慈竹无性系分株的AFCV(J/g)随龄级增大而递增;慈竹无性系水平上的AFCV为:Ⅰ龄占16.47%、Ⅱ龄占25.76%、Ⅲ龄占36.32%、Ⅳ龄为13.08%及Ⅴ龄为8.37%。用恒容燃烧法测定热值时,其能值变化与氧分压密切相关。用经验公式计算的能值较作图法高;用AFCV表示能值较总干重热值(GCV)准确。  相似文献   
53.
2021年8月,在安徽省合肥市庐江县牛王寨采集到东亚腹链蛇属(Hebius)蛇类标本1号。经形态比较发现,该蛇明显不同于大别山地区已有的东亚腹链蛇属物种——棕黑腹链蛇(H. sauteri)和绣链腹链蛇(H. craspedogaster)。分子系统学分析显示,该标本与东亚腹链蛇(H. vibakari)遗传关系最近,且形态上符合东亚腹链蛇特征,提示该标本应为东亚腹链蛇。东亚腹链蛇是安徽省和大别山地区爬行动物分布新记录种,这也是该物种在中国东北地区之外首次被报道。该分布新记录扩大了对东亚腹链蛇的分布范围的认知,对东亚腹链蛇的种群分化和生物地理学研究具有重要意义。  相似文献   
54.
The Asian walnut moth, Garella musculana (Erschov, 1874) (Lepidoptera: Nolidae), is a major pest of walnut. Native to Central Asia, it was found to be invasive in 2008 in Sevastopol (Crimea) and nowadays widespread in Turkey, Bulgaria, Romania and Russia. Here, we account for the finding of G. musculana in NE Italy (Veneto region) in 2021, where adults were found in a light lamp, representing the first record of the Asian walnut moth for this country and Western Europe. Adult specimens were identified morphologically on both external characters and genitalia features. G. musculana larvae and damage were also observed on a plantation of Juglans regia L. (Fagales: Juglandaceae) located in Veneto in October 2021. A COI-barcoding analysis was performed to attain a molecular characterization of our specimens and probate our morphological identification. However, because no sequence of G. musculana was present in major gene databases and the similarity of our sequences with those attributed to Garella ruficirra (Hampson, 1905) (Lepidoptera: Nolidae) made clear that these taxa deserved further scrutiny regarding their specific distinction. Some subtle differences in the male terminalia could be found between them and their vast geographic distributions, but the strong similarity in most features calls for further morphological and genetical insights on a broad set of samples to assess whether they represent two closely related, substantially parapatric species, or a unique, geographically varying entity. Solving this issue may turn out crucial in the identification and proper management of walnut moths of the genus Garella.  相似文献   
55.
采用多导睡眠描记术研究了例脑室注射促甲状腺激素释放激素(TRH)对正常大鼠和去甲状腺大鼠睡眠-觉醒的影响。在正常大鼠,TRH引起觉醒增加,浅慢波睡眠(SWS_1)、深慢波睡眠(SWS_2)和总睡眠时间(TST)均减少,异相睡眠(PS)消失,SWS_1、SWS_2和PS的潜伏期均显著延长,给药后立即产生效应并在1h内达高峰。去甲状腺对大鼠的睡眠-觉醒无明显影响,注射TRH后引起的效应与正常大鼠相似。结果提示TRH有促进大鼠觉醒的作用,对各睡眠时相均有抑制作用,其作用部位可能在下丘脑以外的中枢结构。  相似文献   
56.
该文选取浙江省古田山亚热带常绿阔叶林72种木本植物,探究气候因素、系统发育关系和功能性状对亚热带常绿阔叶林叶衰老物候的影响。结果表明,叶变色期在9—12月,落叶期在10—12月。每月落叶物种数与月均温、月均降水量和月均日照时数没有显著相关性,每月叶变色物种数与月均温和月均日照时数呈弱相关;落叶性对叶变色期和落叶期具有显著影响;植物间系统发育关系对叶变色期和落叶期没有显著影响。因此,生物和非生物因子都会影响常绿阔叶树种的叶衰老,这对于提高秋季物候预测模型具有重要价值。  相似文献   
57.
摘要 目的:探讨参苓白术散联合针刺对溃疡性结肠炎大鼠内质网应激、炎症反应的作用机制。方法:采用三硝基苯磺酸的方法构建溃疡性结肠炎大鼠模型。给予大鼠参苓白术散联合针刺干预。采用ELISA法检测大鼠病变结肠的炎症反应和氧化应激水平;采用肉眼观察各组结肠组织形态学评分;采用Western blot 检测大鼠内质网应激相关蛋白的表达。结果:与空白组相比,模型组、针刺组、参苓白术散、参苓白术散组联合针刺组大鼠体质量更低(P<0.05);与模型组相比,针刺组、参苓白术散、参苓白术散组联合针刺组溃疡指数评分和大鼠体质量更低(P<0.05),且参苓白术散组联合针刺组明显低于针刺组和参苓白术散组;与空白组相比,模型组、针刺组、参苓白术散、参苓白术散组联合针刺组ROS、GSH-Px、MDA更高(P<0.05);与模型组相比,针刺组、参苓白术散、参苓白术散组联合针刺组ROS、GSH-Px、MDA更低(P<0.05),且参苓白术散组联合针刺组明显低于针刺组和参苓白术散组;与空白组相比,模型组、针刺组、参苓白术散、参苓白术散组联合针刺组TNF-α、IL-1β、IL-18更高(P<0.05);与模型组相比,针刺组、参苓白术散、参苓白术散组联合针刺组TNF-α、IL-1β、IL-18更低(P<0.05),且参苓白术散组联合针刺组低于针刺组和参苓白术散组;与空白组相比,模型组、针刺组、参苓白术散、参苓白术散组联合针刺组GRP78、p-PERK、p-eIF2α更高(P<0.05);与模型组相比,针刺组、参苓白术散、参苓白术散组联合针刺组GRP78、p-PERK、p-eIF2α更低(P<0.05),且参苓白术散组联合针刺组明显低于针刺组和参苓白术散组。结论:参苓白术散组联合针刺可有效抑制溃疡性结肠炎大鼠内质网应激,进而抑制炎症反应和氧化应激反应,并促进溃疡性结肠炎大鼠病变病情转归。  相似文献   
58.
The action of rotameric probes introduced either in position 7 or 8 in the sequence of substance P (SP) was investigated, i.e. -tetrahydroisoquinoleic acid (Tic), -fluorenylglycine (Flg), -diphenylalanine (Dip), the diastereoisomers of -1-indanylglycine (Ing) and -benz[ƒ]indanylglycine (Bfi), the Z- and E-isomers of dehydrophenylalanine and dehydronaphthylalanine (ΔZPhe, ΔEPhe, ΔZNal, ΔENal) and (Dmp). The aim of this study was the topographical characterization of the binding subsites of human NK-1 receptor expressed in CHO cells, especially the S7 and S8 subsites, corresponding to residues Phe7 and Phe8 of substance P. According to the binding potencies of these substituted-SP analogues, the S7 binding subsite is smaller than the S8 subsite: the S7 subsite accepts only one aromatic nucleus, while the S8 can accommodate three coplanar nuclei altogether. These findings are compatible with the idea that the S8 binding subsite may reside in the extracellular loops of the hNK-1 receptor. NK-1 agonists bind to human NK-1 receptor and activate the production of both inositol phosphates and cyclic AMP. As already quoted for septide, [pGlu6, Pro9]SP(6–11), discrepancies are observed between affinity (Ki) and activity (EC50) values for IPs production. While a weak correlation between Ki and EC50 values for IPs production could be found (r = 0.70), an excellent correlation could be demonstrated between their affinities (Ki) and their potencies (EC50) for cAMP production (r = 0.97). The high potency (EC50) observed for ‘septide-like’ molecules on PI hydrolysis, compared to their affinity is not an artefact related to the high level of NK-1 receptors expressed on CHO cells since a good correlation was found between EC50 values obtained for PI hydrolysis and those measured for spasmogenic activity in guinea pig ileum bioassay (r = 0.94).

According to the binding potencies of constrained analogues of phenylalanine, the S7 binding subsite of human NK-1 receptor is small, whereas the S8, which can accommodate three coplanar nuclei, might probably reside in the extracellular loop. The discrepancies observed between affinity (Ki) and activity (EC50) values for IPs production are not an artefact of CHO cells since a good correlation was found between EC50 for PI hydrolysis and those measured in guinea pig ileum bioassay.  相似文献   

59.
提出神经元胞浆转运的两相流模型,对胞浆快转运和慢转运进行统一的流体力学描述,给出微粒转运与胞浆流动的定量关系。  相似文献   
60.
建立了多组多滞后区间系数定常非线性控制系统的结构概念,采用鲁棒镇定的等价法,给出了具有扰动结构参数的多组多滞后区问系数定常非线性关联控制大系统的结构与关联鲁棒镇定,同时给出了扰动参数与滞后非线性项界线的估价公式。  相似文献   
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