三尖杉科的花粉形态及其外壁超微结构研究

本文描述了在光学显微镜,扫描电子显微镜和透射电子显微镜下观察到三尖杉科花粉特征,并对三尖杉属种间的花粉特征进行了对比。据此,笔者支持在三尖杉属内建立篦子三尖杉组Ｓｅｃｔ．Ｐｅｃｔｉｎａｔａｅ Ｌ．Ｋ．Ｆｕ和三尖杉组Ｓｅｃｔ．Ｃｅｐｈａｌｏｔａｘｕｓ的意见。根据花粉形态特征,本文讨论了三尖杉科的范围和分类位置,同时对比了三尖杉科和红豆杉科花粉的异同。花粉形态特征说明两科之间有密切的亲缘关系,三尖杉科     

三尖杉科植物RAPD分析及其系统学意义

利用随机扩增多态性ＤＮＡ（ＲＡＰＤ）技术分析了三尖杉科植物三尖杉Ｃｅｐｈａｌｏｔａｘｕｓ ｆｏｒｔｕｎｅｉ Ｈｏｏｋ．ｆ．、粗榧Ｃｅｐｈａｌｏｔａｘｕｓ ｓｉｎｅｎｓｉｓＬｉ、海南粗榧Ｃｅｐｈａｌｏｔａｘｕｓ ｈａｉｎａｎｅｎｓｉｓＬｉ和篦子三尖极Ｃｅｐｈａｌｏｔａｘｕｓ ｏｌｉｖｅｒｉＭａｓｔ。,经筛选Ｏｐｅｒｏｎ公司的４组８０个引物,其中１１４个引物的谱带清晰呈多态性。采用ＵＰＧＭＡ法对各样本     

红豆杉科、三尖杉科和罗汉松科植物叶片结构的比较观察

扫描电镜和光镜下的叶表皮特征以及叶片解剖结构的研究结果,支持在红豆杉科内建立白豆杉属的处理方式;赞同在三尖杉属内建立篦子三尖杉组,叶片解剖结构方面,三尖杉科和红豆杉科的穗花杉属的相似之处颇多。而叶表皮形态特征方面又表现为三尖杉科和罗汉松科更加接近。反映了出了红豆杉科、三尖杉科和罗汉松科之间的密切而又复杂的系统关系。     

抗癌植物篦子三尖杉(Cephalotaxus oliveri Mast.)的研究

从广东产的篦子三尖杉(Cephalotaxus olivert Mast.)中分离出三种生物碱:三尖杉酯碱(harringtonine)、三尖杉碱(cephalotaxine)、schelhammera alkaloid B。其中,三尖杉酯碱在1毫克/公升的剂量下,对小鼠肉瘤 S_(180)的抑制率为42.3%。临床试用,对急性非淋巴型白血病有较好的疗效。我国的篦子三尖杉资源比较丰富,抗癌有效成份三尖杉酯碱的得率较高,达1.3/万,是生产三尖杉酯碱的好原料。     

三尖杉属植物叶片结构的比较观察

本文作者在光学显微镜与扫描电子显微镜下,比较观察了三尖杉属植物叶片构造与叶 表面角质层的特征。 观察结果表明,篦子三尖杉的气孔为双环型,少数为单环型, 单位面积上的气孔平均数较 多(120．6个／mm²), 具皮下层, 叶肉中含有大量丝状石细胞和少量星状石细胞及短石细胞, 叶 下表面角质突起不明显。而三尖杉属的其余种类,气孔均为双环型,气孔平均数较少(47．3一 88．1个／mm²), 除日本粗榧与柱冠日本粗榧外,均无皮下层, 叶肉中具星状石细胞、短石细 胞、纤维状石细胞或完全缺如, 叶下表面具明显的角质突起。依据上述特征以及大体形态和生 物碱成分等有关资料,我们建议在三尖杉属中可分为： 三尖杉组(Sect．Cephalotaxus)和篦子 三尖杉组(Sect．Pectinatae)。 此外,本文还对三尖杉组中的分系与某些种的划分,以及三尖杉科的系统位置进行了讨论。     

部分裸子植物叶片总蛋白分析

采用ＳＤＳ－ ＰＡＧＥ 技术, 分析了红豆杉科（Ｔａｘａｃｅａｅ） 植物南方红豆杉（ Ｔａｘｕｓ ｃｈｉｎｅｎｓｉｓｖａｒ－ ｍａｉｒｅｉ （Ｌｅｍｅｅ ｅｔ Ｌｅｖｌ－） Ｃｈｅｎｇ ｅｔ Ｌ－Ｋ－Ｆｕ） 、穗花杉（ Ａｍｅｎｔｏｔａｘｕｓ ａｒｇｏｔａｅｎｉａ （Ｈａｎｃｅ） Ｐｉｌ ｇｅｒ） 、云南穗花杉（ Ａ－ ｙｕｎｎａｎｅｎｓｉｓ Ｌｉ） 、白豆杉（ Ｐｓｅｕｄｏｔａｘｕｓｃｈｉｅｎｉｉ（Ｃｈｅｎｇ） Ｃｈｅｎｇ） 以及三尖杉科（Ｃｅｐｈａｌｏｔａｘａｃｅａｅ） 、植物三尖杉（ Ｃｅｐｈａｌｏｔａｘｕｓ ｆｏｒｔｕｎｅｉ Ｈｏｏｋ－ｆ－） 、粗榧（ Ｃ－ｓｉｎｅｎｓｉｓ （Ｒｅｈｄ－ｅｔＷｉｌｓ－） Ｌｉ） 、海南粗榧（ Ｃ－ｈａｉｎａｎｅｎｓｉｓ Ｌｉ） 、篦子三尖杉（ Ｃ－ｏｌｉｖｅｒｉ Ｍａｓｔ－） 和罗汉松科（Ｐｏｄｏｃａｒｐａｃｅａｅ） 、植 物罗汉松 （ Ｐｏｄｏｃａｒｐｕｓ ｍａｃｒｏｐｈｙｌｌｕｓ （ Ｔｈｕｎｂ－ ） Ｄ－Ｄｏｎ） 、鸡毛 松（ Ｐ－ｉｍｂｒｉｃａｔｕｓ Ｂｌ－） 、竹柏（ Ｐ－ ｎａｇｉ（Ｔｈｕｎｂ－） Ｚｏｌｌ） 、陆均松（ Ｄａｃｒｙｄｉｕｍ ｐｉｅｒｒｅｉ Ｈｉｃｋｅｌ） 共１２ 种植物的叶片蛋白, 在蛋白质水平上采用     

红豆杉科及相关类群rbc L基因PCR-RFLP分析

运用RFLP方法对红豆杉科及相关类群14种植物叶绿体rbcL基因PCR产物进行限制酶酶切分析,共获29个酶切变异位点。采用PHYLIP 软件包对限制位点变异数据进行极大简约法分析得到18个步长为6的最简约树并求得一致树,结果显示：（1）红豆杉科和三尖杉科属单系群;(2) 穗花杉属Amentotaxus以置于红豆杉科内为宜,不支持将穗花杉属独立成科的处理方式;(3)白豆杉应为红豆杉科内一个属Pseudotaxus;(4) 三尖杉属内篦子三尖杉地位特殊,可设篦子三尖杉组;(5) 不赞同将竹柏类从罗汉松属中分离出去成立新科;(6) 红豆杉科、三尖杉科和罗汉松科三者间,前两者的关系更为接近。     

三尖杉属(科)植物的双黄酮成分及其化学分类的研究

本文采用薄层层析和提取、分离、光谱分析等方法分析研究了三尖杉属植物叶的双黄酮类化合物,根据获得的化学分析结果,我们同意：(1)将三尖杉属分为二个组：篦子三尖杉组Sect．1 Pectinaea,只包括蓖子三尖杉一种;三尖杉组Sect．2 Cephalotaxus,包括本属所有其它种。(2)支持三尖杉科只包括三尖杉属1属,不支持将红豆杉科中的穗花杉属(Amentotaxus)归入三尖杉科的主张。(3) 认为三尖杉科与南洋杉科、松科、杉科和柏科的亲缘关系较远,而与红豆杉科及罗汉松科的亲缘关系密切。     

红豆杉科及相关类群rbcL基因PCR—RFLP分析

运用RFLP方法对红豆杉科及相关类群14种植物叶绿体rbcL基因PCR产物进行限制酶酶切分析,共获29个酶切变异位点。采用PHYLIP软件包对限制位点变异数据进行极大简约法分析得到18个步长为6的最简约树并求得一致树,结果显示：⑴红豆杉科和三尖杉科属单系群;⑵穗花杉属Amentotaxus以置于红豆杉科内为宜,不支持将穗花杉属独立成科的处理方式;⑶白豆杉应为红豆杉科内一个属Pseudotaxus;⑷三尖杉属内篦子三尖杉地位特殊,可设篦子三尖杉组;⑸不赞同将竹柏类从罗汉松属中分离出去成立新科;⑹红豆杉科、三尖杉科和罗汉松科三者间,前两者的关系更为接近。     

篦子三尖杉种子繁殖取得成功

我国二级保护植物篦子三尖杉(Cephalotaxusoliveri),为裸子植物三尖杉科常绿小乔木或灌木树种,主要分布于广东、江西、湖南、湖北、四川、重庆、贵州和云南等省区。由于该植物树体低矮,呈现丛生状,树形优美,种子大而悬垂,是一种优良的观赏绿化树种。     

Synthesis and partial characterization of hydrogels obtained via glutaraldehyde crosslinking of acetylated chitosan and of hyaluronan derivatives

Hydrophilic networks based on functionalized hyaluronic acid and on partially acetylated chitosan, respectively, have been obtained. In the case of hyaluronic acid (HA), primary amino functionalities have been introduced along the polysaccharide chains. The ensuing derivatives, i.e., HA-lysine (HA-K), HA-diamino pentane (HA-DAP), and HA-glycine-lysine (HA-GK), have been characterized by high field NMR spectroscopy. NMR 2D-DOSY experiments have allowed us to optimize the purification procedure. Chitosan was made soluble in water by partial acetylation. Cross-linking reactions have been performed using glutaraldehyde. The obtained networks have been qualitatively characterized by means of (13)C CP-MAS NMR technique. The hydrogels have been characterized also in terms of water uptake.     

孢粉-植被-气候关系研究进展

随着全球变化研究的不断深入 ,第四纪孢粉学研究已取得了长足的进步 ,特别是近些年来 ,孢粉 植被 气候关系研究已成为世界孢粉学界的热点之一。空气孢粉学的研究在大气环境污染监测、花粉过敏症、农业收成预报和第四纪植被与环境重建等方面得到了广泛应用 ,并不断发展 ;近年来 ,为开展全球范围的古环境研究 ,各大洲相继建立了孢粉数据库 ,大量开展表土孢粉研究。中国第四纪孢粉数据库的建立 ,汇集了我国近半个世纪积累的孢粉资料 ,并利用中国第四纪孢粉数据 ,系统开展了中国现代表土孢粉、6kaBP(中全新世 )及 1 8kaBP(末次盛冰期 )的生物群区模拟及重建 ,建立了花粉 气候转换函数和响应面模型 ,并取得了良好的结果 ;冲积物孢粉学和环境考古孢粉学研究 ,也取得了一定成果 ,但研究还有待于深入 ;特征指示种花粉雨研究 ,对古生态环境重建也具有重要的意义。     

溢油对南海海洋生态系统的影响及珠江口溢油现状

详细介绍了溢油的化学组成及其进入水体后的变化过程,在此基础上简述了溢油对海洋中的初级生产力、鸟类、贝类和鱼类等生物的影响,以及对红树林和珊瑚礁等重要生态系统的破坏,并说明了溢油对生物和生态系统的破坏机制.统计了近年来在珠江口及其附近海域发生的溢油事件,综述了国内外有关的研究成果并科学阐明了溢油对南海海洋生态系统可能产生的影响,为相关部门研究相应的溢油应急对策及控制方法提供参考.     

A kinetic model of peroxidation in a lipid bilayer

The structure, thermodynamic, and kinetic features of polyunsaturated fatty acids derivatives as the main substratum of lipid peroxidation (POL) have been considered. The heats of key POL reactions have been estimated. Kinetic consequences of these estimations have been analyzed. The dependence of POL rate on O2 concentration have been considered in detail both in the absence and in the presence of antioxidants. The essential features of POL processes in lipid bilayers resulting from the specific structure and molecular dynamics have been discussed.     

Starch phosphorylase enzymes in developing and germinating pea seeds

Phosphorylase has been fractionated during development and germination of seeds of smooth and wrinkled-seeded peas. The total phosphorylase levels have been compared. In addition, a number of other pea tissues and other legumes have been examined. Some kinetic properties of the two enzymes present have been measured. Both enzymes have been further purified by affinity chromatography on Sepharose 4B-starch columns and by sequential gel filtration in the absence and presence of amylopectin. The MW and sub-unit structures of the two enzymes have been examined and their possible roles discussed.     

Potential fields and barriers to diffusion in narrow cylindrical capillaries

In this paper, the wall potential along the center line of narrow solid capillaries has been derived. The potential barriers at the open end of such capillaries have been studied in detail. The influence of these potential barriers on the diffusion coefficients and their dependence on temperature and capillary radius have been evaluated. The implications of these energy barriers in the clarification of low pressure hysteresis phenomena have been pointed out.     

Analysis of the aliphatic 1H-NMR spectrum of plasminogen kringle 4. A comparative study of human, porcine, bovine and chicken homologs

The aliphatic 1H-NMR spectrum of the kringle 4 domain of human plasminogen has been studied via two-dimensional chemical shift correlated (COSY) and nuclear Overhauser correlated (NOESY) experiments at 300 MHz and 620 MHz. A number of aliphatic proton spin systems have been identified and several definite assignments have been made. This was mainly achieved by comparison of the human kringle 4 spectrum with spectra of the porcine, bovine and chicken homologs and also with that of the kringle 1 from human plasminogen on which we have reported previously. The three valyl and two leucyl residues of human kringle 4 have been assigned. The eleven threonyl spin systems have been identified via a RELAYED-COSY experiment and Thr17 has been assigned. The three alanyl spin systems have been identified and assigned. Six seryl spin systems have been identified and the signals from the seven glycyl residues of human kringle 4 have been located with Gly45 assigned. Furthermore, 24 AMX spin systems have been mapped in the COSY spectrum of human kringle 4 and H alpha-H beta,beta' spin systems of Tyr2, Tyr41, Tyr50, Tyr74, Trp25 and Trp62 have been assigned. From the spectrum of a deglycosylated chicken homolog, the epsilon-methyl singlets of Met28 and Met48 have been assigned. Finally, ligand effects on selected aliphatic resonances were observed which could be analyzed in terms of residues likely to neighbor the kringle lysine-binding site.     

Diagnosis of Helicobacter pylori

The different invasive and noninvasive diagnostic tests for Helicobacter pylori have been applied mainly in emerging countries. Molecular methods have been developed, especially a test for detection of H. pylori and its clarithromycin resistance directly from stools. The long-term effects of eradication on histologic lesions have been studied in a meta-analysis and the prognostic value of post-treatment in gastric mucosa-associated lymphoid tissue lymphoma has been assessed. An operating link for gastritis assessment (the OLGA staging) has also been published. Attempts to simplify the urea breath test protocol have been made, and new stool antigen tests have been proposed and compared to those previously available.     

Effects of variation on extensor elements and operative procedures in patellofemoral disorders

The influence of both insertion and strength/elasticity of each extensor in patellofemoral disorders was fully investigated through a two-dimensional mathematical model analysis in a horizontal plane, in combination with experimental design theory for analyzing mutually correlated influences. In the model, patellofemoral joint profiles projected on a horizontal plane have been expressed as spline functions. Each muscle of the quadriceps has been represented as a string pulled by the respective force; fascias and tendons have been represented by springs. Nonlinear equations have been constructed to represent the forces involved, and then solved by numerical iteration. An analysis of variance was performed on the data derived from a series of simulations, obtaining the following results. The strength of most extensors has been shown to have an influence on the increase in lateral contact force but not patellar translation. The tibial tubercle position has significant influence on both patellar translation and lateral contact force. The quadriceps' insertion on the femur has no influence on patellar translation. The insertion of each extensor on the patella has been shown to have a strong effect on patellar translation but not on contact force.     

Integration of the Physical and Genetic Linkage Map for Human Chromosome 13

We have used a panel of somatic cell hybrids containing different rearrangements of human chromosome 13 to integrate genetic and physical maps of this chromosome. The positions of 17 translocation/deletion breakpoints on human chromosome 13 have been determined relative to the microsatellite markers on the genetic linkage map compiled by Généthon. Because markers on maps from several other Consortium groups have also been analyzed using many of the same hybrids, it was possible to relate these with the Généthon map. The position of all of the chromosome breakpoints have been placed, wherever possible, between two adjacent markers on the genetic linkage maps using PCR analysis for the presence/absence of the markers in the somatic cell hybrids. The positions of the breakpoints have already been determined cytogenetically, and some of these breakpoints are located at landmark positions on the chromosome. The relative density of markers along the chromosome differs between independently derived maps, and, based on the known locations of certain breakpoints in the physical map, inconsistencies in the genetic maps have been identified.