宜溧山区药用蕨类资源调查

据调查统计,宜溧山区现有蕨类植物26科、44属、82种,其中40种左右有药用价值.对这些药用蕨类的生境、药用功效、利用现状等作了简要阐述,并就其开发和利用提出了相关的建议.     

Repeated Cocaine Alters Glutamate Receptor Subunit Levels in the Nucleus Accumbens and Ventral Tegmental Area of Rats that Develop Behavioral Sensitization

Increased glutamate transmission in the nucleus accumbens and ventral tegmental area has been proposed as a mechanism underlying sensitized behavioral responses to repeated cocaine administration. GluR1, GluR2/3, and NMDAR1 subunits of glutamate receptors were quantified from immunoblots in these brain nuclei in rats at 24 h and 3 weeks after discontinuing 1 week of daily cocaine injections. Motor behavior was monitored after the first and last injections of daily cocaine, and those rats that showed >20% increase in motor activity after the last compared with the first injection were considered to have developed behavioral sensitization. The subjects that developed behavioral sensitization showed a significant increase in GluR1 levels in the nucleus accumbens at 3 weeks but not at 24 h of withdrawal. Conversely, sensitized animals showed a significant increase in NMDAR1 and GluR1 levels in the ventral tegmental area at 1 day but not at 3 weeks of withdrawal. None of these increases occurred in the rats exposed to daily cocaine that did not develop behavioral sensitization (<20% increase in motor activity), and no changes were measured in the level of GluR2/3 in any treatment group. The functional importance of the increases in glutamate receptor subunit levels is suggested by the fact that the changes were present only in rats that developed behavioral sensitization to repeated cocaine administration.     

蛋白质组学进展

在蛋白质水平上定量、动态、整体性研究生物体的蛋白质组学 ,将在后基因组时代大大增进我们对基因功能的理解。简要介绍了蛋白质组学的概念、研究手段 ,及最新进展     

黄土丘陵区不同侵蚀环境下土壤有机碳对植被恢复的响应

植被恢复是提高土壤有机碳累积和储存的重要措施。以黄土丘陵区两个典型侵蚀环境下的小流域即黄土区坊塌流域和砒砂岩区满红沟流域退耕坡面为研究对象,分析了土壤有机碳含量(SOCC)、有机碳密度(SOCD)在同一侵蚀环境不同群落下的变化以及在同一群落不同侵蚀环境间的差异,旨在探明不同侵蚀环境下土壤有机碳对植被恢复的响应。结果表明:1)同一侵蚀环境下,与坡耕地相比,自然恢复方式下退耕地植被恢复初期SOCC、SOCD均显著降低,之后随植被恢复均显著升高(P0.05);人工恢复方式下退耕地20—25年柠条锦鸡儿群落和13—14年刺槐群落SOCC、SOCD均显著升高(P0.05),说明同一侵蚀环境内,退耕地在两种恢复方式下均能显著提高土壤有机碳累积和储存。2)同一侵蚀环境下,与相近恢复年限的自然恢复群落相比,刺槐群落SOCC、SOCD均显著高于长芒草+铁杆蒿群落(P0.05),砒砂岩区柠条锦鸡儿群落SOCC、SOCD均显著低于铁杆蒿群落(P0.05),黄土区柠条锦鸡儿群落SOCC显著低于而SOCD显著高于铁杆蒿群落(P0.05),说明相同恢复时间内,相对于自然恢复方式,人工刺槐造林在两种侵蚀环境下均能累积与储存较多的土壤有机碳,而柠条锦鸡儿造林在两种侵蚀环境下累积土壤有机碳的效果均不佳,在黄土区储存土壤有机碳效果好于砒砂岩区。3)同一群落下,黄土区人工和自然恢复群落SOCC均高于砒砂岩区;黄土区人工恢复群落SOCD均显著高于而自然恢复群落SOCD均低于砒砂岩区(P0.05),说明黄土区人工恢复累积和储存土壤有机碳及自然恢复累积土壤有机碳的效果较好,而砒砂岩区自然恢复储存土壤有机碳的效果较好。     

Surface metabolites of the brown alga Taonia atomaria have the ability to regulate epibiosis

This study aimed to improve understanding of the strategies developed by the Mediterranean seaweed Taonia atomaria to chemically control bacterial epibiosis. An experimental protocol was optimized to specifically extract algal surface-associated metabolites by a technique involving dipping in organic solvents whilst the integrity of algal cell membranes was assessed by fluorescent microscopy. This methodology was validated using mass spectrometry-based profiles of algal extracts and analysis of their principal components, which led to the selection of methanol as the extraction solvent with a maximum exposure time of 15 s. Six compounds (A–F) were identified in the resulting surface extracts. Two of these surface-associated compounds (B and C) showed selective anti-adhesion properties against reference bacterial strains isolated from artificial surfaces while remaining inactive against epibiotic bacteria of T. atomaria. Such specificity was not observed for commercial antifouling biocides and other molecules identified in the surface or whole-cell extracts of T. atomaria.     

Achene morphology of Saussurea species (Asteraceae,Cardueae) in Korea and its systematic implications

Achene size and shape, surface sculpturing, and pericarp and testa wall structure of 23 Korean Saussurea spp. were investigated using scanning electron microscopy (SEM) and light microscopy to evaluate the infrageneric relationships and assess their systematic significance. Achene size categories and thickness of the testa epidermis were distinguished using biometric measurements. Four basic types of surface pattern were observed: (1) lineate; (2) striate; (3) reticulate; and (4) colliculate. Saussurea rorinsanensis was found to have some unique achene characteristics, such as a fusiform achene, uniform pappus, presence of epidermal hairs and tangentially elongated, narrow testa epidermal cells. The characteristic achene features for species were found to be achene size and shape, hilum position, surface sculpture, pappus composition, morphology of the pericarp wall and thickness of the testa epidermis. Based on 16 morphological and achene characters, a cladistic analysis resolved three well‐supported clades, with S. eriophylla as the first‐branching taxon. Saussurea pulchella and S. japonica, both belonging to Saussurea subgenus Theodorea, were distant from each other in the 50% majority rule consensus tree and the character distribution cladogram. This cladistic analysis of achene morphology and anatomy should be regarded as giving us a tentative picture of the phylogenetics of Saussurea, and this study may serve as a reference for future hypotheses and studies on the characterization and classification of Saussurea spp. in Korea.     

基于RS和GIS的干旱区内陆河流域生态系统质量综合评价——以石羊河流域为例

石羊河流域是河西走廊东段重要生态区,也是用水矛盾最突出、生态环境问题最严重的地区之一,对其进行生态系统质量的评价,可为干旱区内陆河流域的生态保护工作提供借鉴.依据生态系统质量概念,以统计数据、遥感数据和土地覆被数据为基础,从生态系统的3方面(生产力、稳定性和承载力)构建评价指数,基于非参数Kruskal-Wallis卡方(χ²)检验和熵值法确定指标权重,结合RS、GIS和SPSS软件对2000、2005、2010和2015年石羊河流域不同生态系统类型的质量及各指数进行综合评价及变化分析.结果表明: 2000—2015年,石羊河流域生态系统质量均值为57.76,呈现显著下降趋势,年降幅为0.72,空间分布呈上游优于中游、中游优于下游的状态;生态系统生产能力、稳定性和承载力均值分别为67.52、45.37、58.53,生产能力和稳定性小幅上升,承载力逐渐下降.就各生态系统类型来看,森林生态系统质量最高,年均值为78.12,年降幅最小,为0.28;其次是草地、农田和城镇生态系统,年均值分别为62.45、58.76、50.29;湿地生态系统质量最低,年降幅最大,达0.98.     

Arbuscular mycorrhizal fungi: a specialised niche for rhizospheric and endocellular bacteria

Arbuscular mycorrhizal (AM) fungi produce an extensive hyphal network which develops in the soil, producing a specialised niche for bacteria. The aim of this paper is to review briefly the interactions shown by these symbiotic fungi with two bacterial groups: (i) the plant-growth promoting rhizobacteria (PGPRs) which are usually associated with fungal surfaces in the rhizosphere, and (ii) a group of endocellular bacteria, previously identified as being related to Burkholderia on the basis of their ribosomal sequence strains. The endobacteria have been found in the cytoplasm of some isolates of AM fungi belonging to Gigasporaceae and offer a rare example of bacteria living in symbiosis with fungi. This revised version was published online in August 2006 with corrections to the Cover Date.     

Initiation of acellular extrinsic fiber cementum on human teeth

Summary The development of acellular extrinsic fiber cementum (AEFC) has never before been studied in human teeth. We have therefore examined the initiation of AEFC in the form of a collagenous fiber fringe and its attachment to the underlying dentinal matrix, in precisely selected, erupting human premolars with roots developed to 50%–60% of their final length. Freshly extracted teeth were prefixed in Karnovsky's fixative, decalcified in EDTA and subdivided into about 10 blocks each, cut from the mesial and distal root surfaces, vertical to and along the root axis. The blocks were postfixed in osmium tetroxide, embedded in Epon and cut for light- and electron-microscopic investigation. Starting at the advancing edge of the root, within a region extending about 1 mm coronal to this edge, fibroblast-like cells were seen closely covering the external root surface. Along the first 100 m from the root edge, these cells extended cytoplasmic processes and contacted the dentinal collagen fibrils. Between these cells and the dentinal matrix, new collagen fibrils and very short collagen fibers gradually developed. Within the second 100 m from the root edge, this resulted in the formation of a cell-fiber fringe network. Newly formed fibers of the fringe were directly attached to the non-mineralized matrix containing dentinal collagen fibrils and could be distinguished from the latter by differences in fibril orientation. During the process of dentin mineralization, the transitional zone between the fiber-fringe base and the dentinal matrix, i.e., the future dentino-cemental junction, also mineralized. It is suggested that this fiber fringe is the base of AEFC, which later increases in thickness by fiber extension and subsequent mineralization.Abbreviations AEFC acellular extrinsic fiber cementum - AIFC acellular intrinsic fiber cementum - CIFC cellular intrinsic fiber cementum - CMSC cellular mixed stratified cementum - ARE advancing root edge - CP cytoplasmic process - D dentin - DCJ dentinocemental junction - E enamel - EBL external basal lamina - EC epithelial cell - EDTA ethylene diaminetetraacetic acid - ERM epithelial rests of Malassez - FF fiber fringe - HRS Hertwig's epithelial root sheath - IBL internal basal lamina - MD mineralized dentin - NMD non-mineralized dentin - OB odontoblast - PD predentin - PL periodontal ligament     

沙棘果渣总黄酮提取工艺优化及抗氧化活性研究

利用果胶酶协同超声波法,对沙棘果渣有效成分总黄酮的提取工艺及其抗氧化活性进行了研究.以提取率为指标,通过酶用量、液料比、乙醇浓度、提取时间、提取温度、超声功率等单因素分析,选定酶用量、液料比、超声提取时间3个因素进行响应面试验,确定提取优化工艺条件为:果胶酶用量5.1％,液料比41∶1,超声提取时间81 min,此条件...