香椿属中三萜类化学成分及生物活性研究进展

香椿属植物在我国民间应用广泛,自1846年香椿属建立以来,不少学者已经对本属植物进行各方面的研究,包括植物生态学和植物化学方面。但到目前为止还不曾见到对该属植物中化学成分和生物活性方面的研究进展进行综述报道。目前对香椿属植物化学成分及生物活性的报道相对集中在三萜类成分,此类成分也是香椿属所在的楝科其他植物特征性成分,该科植物中存在特有的新奇的三萜类成分,不论是化学成分还是生物活性方面都是是当前的研究热点。鉴于此作者对目前国内外报道的香椿属植物中三萜类成分的化学成分及其生物活性研究进行归纳总结,特别是香椿属中三萜的类型以及不同类型三萜代表性的生物活性进行系统归纳,以便为以后研究香椿属其他植物或进一步深入研究开发提供文献支持。     

风轮菜属植物皂苷成分研究进展

风轮菜属植物多为民间药用植物,皂苷类化合物为该属植物的主要活性成分,本文报道自1990年以来风轮菜属植物皂苷成分的研究进展。     

福建茫荡山黄枝润楠群落地理成分分析

对福建茫荡山黄枝润楠群落进行调查分析。结果表明,该群落现有种子植物74科134属195种,隶属9个科分布区类型和13个属分布区类型。该群落区系的热带地理成分占优势,共计45科86属,分别占该群落种子植物科、属数的80.4%和68.8%(不含世界分布,下同),其中,成分最多的是泛热带分布(33科,32属),占该群落种子植物科、属数的58.9%和25.6%。温带分布成分共计11科37属,分别占种子植物科、属数的19.6%和29.6%。体现了该群落植物种类丰富、地理成分复杂、热带成分明显、温带成分较多、起源古老和特有成分较多的特点。     

米仔兰属化学成分及生物活性研究进展

米仔兰属植物在我国民间应用较多,已有不少学者从植物生态学和植物化学等方面对本属植物进行了广泛研究,但相关进展综述迄今尚未见报道。目前对米仔兰属植物化学成分及生物活性的报道较多集中于三萜类成分,该成分因其结构新奇成为米仔兰属所在楝科植物的特征性成分,因此其化学成分及生物活性均为当前研究热点。鉴于此,作者对国内外已报道的米仔兰属植物中化学成分及其生物活性研究进行归纳总结,特别关注其中三萜的不同类型及代表性活性,拟为进一步深入、系统地研究开发米仔兰属其它植物提供参考。     

子午岭种子植物区系分析

子午岭林区计有种子植物94科361属689种。其中裸子植物3科8属10种1变种;被子植物91科353属678种。中国特有属8个,特有种271个,子午岭特有种1个。其种子植物区系的基本特征是：植物种类相对丰富;区系成分复杂,多种成分交汇;区系组成以华北成分为主体,以温带成分占优势;南北区系成分存在差异,垂直分布带谱不明显;在中国植物区系上隶属于泛北极植物区中国-日本森林植物亚区的华北地区黄土高原植物亚地区。     

晋东南山地种子植物区系研究

晋东南山地有野生种子植物974种,隶属于456属125科,其中裸子植物7科11属15种,被子植物118科445属959种(其中双子叶植物104科396属833种,单子叶植物14科,49属126种)。种子植物属的区系成分复杂多样,以温带成分占绝对优势(温带属250属,占总属数的60．98％)。种子植物种的区系成分中,中国特有种占绝对优势,共有383种,占总种数的39．32％,它们是构成晋东南山地森林植被和灌丛植被的建群种和优势种的主要成分。     

秦岭南坡中段种子植物区系初步分析

秦岭南坡中段有种子植物152科,815属,2184种,对该地区植物区系进行了统计分析,结果表明,（1）本地区种子植物种类丰富,共有裸子植物5科,15属,30种,单子叶植物23科,169属,390种;双子叶植物124科,631属,1764种。（2）属的地理分布类型种类多,有15个分布类型及19个变型,其中温带成分占64.17%,具一定的优势。但同时表现亚热带成分向温带成分过渡的特点。（3）本地区植物古老、残遗、原始成分多,反映了该地区植物区系古老的性质。（4）有中国种子植物特有属41属。国家级保护植物32种,分析结果认为本地区是秦岭种子植物区系的重要组成部分。     

大中山自然保护区种子植物区系研究

云南省大中山自然保护区有种子植物749种,隶属于137科396属。区系成分中,世界分布33属,占全部总属数的8.33%;热带分布206属,占除世界分布属以外的56.75%(下同),温带分布148属,占40.77%,中国特有9属,占2.48%。该地区植物种类丰富,种子植物区系起源古老,地理成分复杂,具有明显的亚热带特性。从区系成分和植物类群多样性所占比例上看,是一个需要重点保护的区域。     

庐山兰科植物资源及其保护

通过对庐山兰科植物资源的调查,并对区内兰科植物进行区系成分分布、生态型和生态环境分析,表明庐山共有兰科植物23属41种,属的区系以热带成分和温带成分为主,更兼容世界分布、东亚分布和中国特有分布的区系成分;生态型只有地生和附生2种类型。     

美姑大风顶自然保护区种子植物区系分析

四川美姑大风顶国家级自然保护区有种子植物 1 1 8科 ,3 85属 ,860种 ,其中裸子植物 5科 ,1 6属 ,1 9种 ;被子植物 1 1 3科 ,3 69属 ,841种。种子植物属、种的区系成分共有 1 3个类型 ;在所有成分中 ,以温带区系成分为主 ,达 1 81属 ,占总属数的 5 1 .5 8%。中国特有分布属共 1 1属 ,占总属数的 3 .1 3 % ;中国特有分布种共41 0种 ,占总种数的 48.41 %。保护区共有珍稀濒危植物 1 8种 ,其中国家一级保护植物 4种 ,国家二级保护植物 6种 ,国家三级保护植物 8种。     

Cell wall alterations in staphylococci growing in situ in experimental osteomyelitis

When cells of both Staphylococcus aureus and Staphylococcus epidermidis are grown in batch culture in nutrient-rich media, their cell walls are regular in thickness, their cell size is within the normal range for each species, and their septation patterns are orderly. When cells of each of these species are examined directly in infected tissue in the rabbit tibia model infection, their cell wall thickness is often much increased and very irregular around the circumference of the cell, their cell size is often increased, and their septation patterns are often severely deranged. All of these alterations in cell wall structure occur in the absence of antibiotics, and we suggest that they may be an expression of phenotypic plasticity in response to altered environmental conditions such as specific nutrient limitations, the presence of antibacterial factors, and growth of the cells on hard surfaces such as rabbit bone or plastic catheters. Some of these specific cell wall alterations are also seen when staphylococcal cells are exposed, in vitro or in vivo, to antibiotics such as clindamycin, but we emphasize that growth in tissue alone is sufficient for their induction.     

The effects of partner togetherness on salivary testosterone in women in long distance relationships

The present study examined whether women's testosterone levels are influenced by being with a sexual and romantic partner after a period of sexual abstinence. Women in long distance relationships (n = 15) provided five saliva samples: at least 1 week before seeing their partner (and at least 2 weeks since their last visit), the day before seeing their partner, when they were with their partner but prior to engaging in sexual activity, the day after their first sexual activity, and 3 days after they were separated from their partners. Salivary testosterone was lowest when participants had been away from their partners for at least 2 weeks and highest the day before they were to see their partners and the day after sexual activity. Results from this study indicated that women's testosterone increased both the day before they were with their partners and they day after they first engaged in sexual activity. However, something about initially reuniting with their partners returned their testosterone to baseline levels, which may be an effect of being in the same location as a partner, or just a state fluctuation due to nervousness or other psychological state.     

猕猴桃茎尖超低温保存过程中超微结构观察

应用透射电镜观察了猕猴桃组培苗茎尖细胞在玻璃化法超低温保存过程中的超微结构变化.研究发现:在预培养、PVS2脱水处理过程中,茎尖细胞内液泡逐渐变多、变小,质壁分离愈加显著,表明细胞的抗冻力增强;在随后的冷冻和解冻过程中,部分细胞的质壁分离更加严重,细胞壁与细胞膜之间出现液腔,细胞器变得模糊,有些细胞的细胞膜、甚至细胞壁撕裂,细胞腔内留下破碎的细胞膜和细胞残片,细胞结构破坏严重,这可能是导致材料在恢复培养中死亡的原因之一;部分细胞经过7d的恢复培养后,细胞器清晰,细胞膜完好并紧贴细胞壁,细胞中央出现较大的液胞,具有与对照相似的结构特征,最终存活下来并能够再生植株.     

Developmental changes in mother-offspring grooming in Japanese macaques

A cross-sectional analysis was made of developmental changes in mother-offspring grooming in Japanese macaques, Macaca,. fuscata. When offspring were immature, time spent grooming by their mothers decreased with offspring age. Soliciting by offspring increased steadily with age, in contrast to their successful soliciting, which decreased gradually until early adolescence. This is in accord with the hypothesis that grooming is one form of post-weaning maternal investment, which may entail behavioral conflict between mothers and immature offspring. On the other hand, mothers spent much more time for grooming of their adult female offspring than for their adolescent male and female offspring. It is argued that grooming by mothers may shift from a form of maternal investment in their offspring to a benefit to be exchanged reciprocally with them. © 1995 Wiley-Liss, Inc.     

我国陆地棉基础种质表型性状的遗传多样性分析

选用43份陆地棉基础种质为研究材料,随机区组排列种植,并进行果枝数、铃数、株高等田间性状调查和衣分、铃重、纤维品质等测定.按照不同时期、不同来源、不同生态区对这些基础种质分别进行表型性状的遗传多样性分析.结果表明:基础种质间在产量、品质、农艺性状等表型性状上差异显著或极显著,遗传多样性指数为0.88;3期基础种质大部分性状差异不显著,但第2、3期基础种质比第1期的纤维长、整齐度高、细度好、衣分增加、早熟性提高、抗病和耐旱性增强,第2期基础种质遗传多样性和遗传丰富度最高;来自不同棉区的基础种质表型性状差异较大,黄河流域棉区基础种质综合性状较好,长江流域棉区产量性状较高,北部特早熟棉区早熟性好,美国引进种质抗黄萎病性较强;国内基础种质比国外品种在纤维长、强、细上的变异系数均有不同程度降低,但国内基础种质表型多样性比引进品种高.以上研究说明引进品种经过长期的环境适应、自然选择和人工选育后,产生了表型变异较为丰富的基础种质类型.     

Song learning in domesticated canaries in a restricted acoustic environment

Many songbirds learn their songs early in life from a song model. In the absence of such a model, they develop an improvised song that often lacks the species-typical song structure. Open-ended learners, such as the domesticated canary, are able to modify their songs in adulthood, although the mechanisms that guide and time the song-learning process are still not fully understood. In a previous study, we showed that male domesticated canaries lacking an adult song model in their first year substantially change their song repertoire and composition when exposed to normally reared conspecifics in their second year. Here, we investigate song development in descendants of canaries that were raised and kept as a peer group without a song model. Such males represent tutors with abnormal song characteristics. Interestingly, the F₁ generation developed quite normal song structure, and when brought into an environment with normally raised canaries in their second year, they did not modify their songs substantially. These results suggest that contact with an adult song model early in life is crucial for song crystallization, but also that song development is at least partly guided by innate rules. They also question the existing classification of canaries as open-ended learners.     

羊肚菌多糖研究进展

羊肚菌多糖是羊肚菌中重要的药用活性成分,对羊肚菌多糖的国内外研究概况、提取分离纯化步骤及其纯度、含量测定、结构鉴定、分析方法和免疫药理作用等作了详细介绍。     

青藏高原几种高寒植物的抗寒生理特性

研究了青藏高原高寒地区3种多年生植物在生长过程中植物叶组织的可溶性糖、脯氨酸和丙二醛（MDA）含量、超氧化物歧化酶（SOD）和过氧化物酶（POD）活性的变化及其生理特性。结果表明;矮嵩草（Kobresia humilis）、垂穗披碱草（Elymus nutans）和黑褐苔草（Carex atro-fusca）叶中的可溶性糖含量随着生长期的进程而增加;脯氨酸含量的变化因植物种类的不同而表现各异,其中在各生长期．垂穗披碱草的脯氨酸含量均高于矮嵩草和黑褐苔草,并在草盛中期表现出明显的差异;3种高寒植物叶片中的丙二醛（MDA）含量随着生长季和气温的变化而呈现不断增加的趋势;3种植物中的超氧化物歧化酶（SOD）和过氧化物酶（POD）活性表现出随生长期和气温变化而改变的趋势,但黑褐苔草的2种膜保护酶活性最高,垂穗披碱草的次之．矮嵩草最低。可见,在不同生长季,这3种高寒植物的抗寒生理反应或低温适应方式可能是多途径的．其中在抗寒物质代谢、膜脂过氧化能力和抗氧化酶系统等方面,有生理反应的共同规律和各自特有的生理抗寒特性．其适应性与抗逆性有所不同,这种差异和生理特性可能与高寒植物的遗传特性和极端高寒低温环境胁迫有关。     

Inclusive fitness in agriculture

Trade-offs between individual fitness and the collective performance of crop and below-ground symbiont communities are common in agriculture. Plant competitiveness for light and soil resources is key to individual fitness, but higher investments in stems and roots by a plant community to compete for those resources ultimately reduce crop yields. Similarly, rhizobia and mycorrhizal fungi may increase their individual fitness by diverting resources to their own reproduction, even if they could have benefited collectively by providing their shared crop host with more nitrogen and phosphorus, respectively. Past selection for inclusive fitness (benefits to others, weighted by their relatedness) is unlikely to have favoured community performance over individual fitness. The limited evidence for kin recognition in plants and microbes changes this conclusion only slightly. We therefore argue that there is still ample opportunity for human-imposed selection to improve cooperation among crop plants and their symbionts so that they use limited resources more efficiently. This evolutionarily informed approach will require a better understanding of how interactions among crops, and interactions with their symbionts, affected their inclusive fitness in the past and what that implies for current interactions.     

Evolution in the pentastomids

The Pentastomida, or tongue worms, form an aberrant group of annulated endoparasites little known to most parasitologists and veterinarians. Although there is no doubt of their affiliation to arthropods, textbooks often rank the Pentastomida as a separate phylum. Riley's many publications on the group have 'promoted it from the realm of the completely unknown to the semi-obscure', but still much research is needed on their basic biology, as little is known about their biochemistry, ecology or their evolutionary relationships. This review by Rolf Haugerud is intended to inspire curiosity about the Pentastomida by discussing their evolution in relation to their phylogeny, host relationships, geographic distribution, transmission and impact.