Rotary torque produced by proton motive force in FoF1 motor

We have attempted direct observation of the light-driven rotation of a FoF(1)-ATP motor. The FoF(1)-ATP motor was co-reconstituted by the deletion-delta subunit of FoF(1)-ATP synthase with bacteriorhodopsins (BRs) into a liposome. The BR converts radiation energy into electrochemical gradient of proton to drive the FoF(1)-ATP motor. Therefore, the light-driven rotation of FoF(1)-ATP motor has been directly observed by a fluorescence microscopy using a fluorescent actin filament connected to beta-subunit as a marker of its orientation. The rotational torque value of the Fo motor was calculated as 27.93+/-1.88pNnm. The ATP motor is expected to be a promising rotary molecular motor in the development of nanodevices.     

西南岩溶地区黄荆和檵木叶片结构对其生态环境的响应

应用常规石蜡切片法对生长于桂林毛村岩溶区和非岩溶区的黄荆(Vitex negundo)和檵木(Loropetalumchinense)的解剖特征进行了比较研究,并对两区的黄荆叶片表皮形态进行了扫描电镜观察.结果显示:(1)两地的黄荆叶片背面均有浓密的绒毛,但致密程度有差异,岩溶区黄荆叶片的气孔深藏于绒毛间隙,这种结构可减少水分蒸发,降低因岩溶干旱带来的水分缺失.(2)岩溶区黄荆和檵木的叶片厚度、上下表皮厚度、栅栏组织的厚度以及栅栏组织的致密程度均大于非岩溶区,这些特征有利于减少水分蒸腾.(3)岩溶区黄荆和檵木叶片的维管组织发达程度高于非岩溶区,有利于在蒸腾减小的情况下促进水分运输和营养元素的迁移,说明2种植物叶片结构特征在不同生境区的改变是其长期在岩溶区干旱环境条件下形成的适应性变化.     

土贝母的化学成分研究

采用反复柱色谱方法进行分离,通过理化性质和波谱分析鉴定结构。从土贝母(Bolbostemma paniculatum)分离并鉴定了8个化合物,分别为：麦芽酚(Ⅰ)、大黄素(Ⅱ)、△^7,22,25-豆甾三烯-3-醇(Ⅲ)、△^7,22,25-豆甾三烯醇-3-O-β-D-吡喃葡萄糖苷(Ⅳ)、α-羟基丙酬葡萄糖苷(V)、β-D-葡萄糖2→1 β-D-葡萄糖苷(Ⅵ)、胡萝卜苷(Ⅶ)、正三十一烷(Ⅷ)。化合物V～Ⅷ为首次从该属中分离得到。     

Binding model for eriodictyol to Jun-N terminal kinase and its anti-inflammatory signaling pathway

The anti-inflammatory activity of eriodictyol and its mode of action were investigated. Eriodictyol suppressed tumor necrosis factor (mTNF)-α, inducible nitric oxide synthase (miNOS), interleukin (mIL)-6, macrophage inflammatory protein (mMIP)-1, and mMIP-2 cytokine release in LPS-stimulated macrophages. We found that the anti-inflammatory cascade of eriodictyol is mediated through the Toll-like Receptor (TLR)4/CD14, p38 mitogen-activated protein kinases (MAPK), extracellular-signalregulated kinase (ERK), Jun-N terminal kinase (JNK), and cyclooxygenase (COX)-2 pathway. Fluorescence quenching and saturation-transfer difference (STD) NMR experiments showed that eriodictyol exhibits good binding affinity to JNK, 8.79 × 10⁵ M^-1. Based on a docking study, we propose a model of eriodictyol and JNK binding, in which eriodictyol forms 3 hydrogen bonds with the side chains of Lys55, Met111, and Asp169 in JNK, and in which the hydroxyl groups of the B ring play key roles in binding interactions with JNK. Therefore, eriodictyol may be a potent anti-inflammatory inhibitor of JNK. [BMB Reports 2013; 46(12): 594-599]     

Evolutionary trends in Tetrastigma (Vitaceae): Morphological diversity and taxonomic implications

Tetrastigma (Miq.) Planch. (Vitaceae) is a genus with ca. 100 species showing great morphological diversity. Previous molecular phylogenetic studies suggested that traditional classification systems are not consistent with the molecular phylogeny, and Tetrastigma is undergoing further systematic investigation. We traced the evolutionary trends of 20 morphological characters within a robust phylogenetic framework. Our results revealed that many morphological characters show either multiple transitions or few state changes, however, some characters show distinct variation. The two subgenera in Tetrastigma (subgen. Tetrastigma and subgen. Palmicirrata) based on unbranched/bifurcate versus digitately branched tendrils are not supported because subgen. Tetrastigma is paraphyletic. However, the unbranched versus bifurcate/digitately branched tendril is of taxonomic utility to characterize some of the major clades. Inflorescences in Tetrastigma appear axillary, but are leaf‐opposed on a compressed axillary shoot. We found most of the species in Tetrastigma retained the ancestral compound dichasial inflorescence, except those of clade IV that have derived pseudo‐umbellate inflorescences. Other characters including habit, leaf organization, and berry shape provide additional morphological support for the major clades. Our morphological analysis and recent molecular study suggest each of the five major clades within Tetrastigma be treated as distinct taxonomic sections (five sections in the genus).     

对6个国外城市街道规划设计导则的解析——“如何规划步行友好的城市街道开放空间？”

本文将“如何通过街道规划设计,营建步行友好的城市开放空间环境,提高居民生活质量？”作为研究视角,抽取了6个国外城市街道规划设计导则中与“如何规划设计步行友好的城市开放空间？”密切相关的内容,根据相关导则编制的逻辑将内容进行提炼、归纳和重组。针对中国通过改善街道步行环境建设高品质城市的诉求以及相关导则中缺少对使用者需求关注的现状,提出了将需求调查纳入规划规定环节、从环境特征角度出发进行街道分类与定位、关注地域特征与集约性生态设施的环境营造方法以及提升步行道功能多样性和空间相容性的建议。     

The efficacy of DNA barcoding in the classification,genetic differentiation,and biodiversity assessment of benthic macroinvertebrates

Macroinvertebrates have been recognized as key ecological indicators of aquatic environment and are the most commonly used approaches for water quality assessment. However, species identification of macroinvertebrates (especially of aquatic insects) proves to be very difficult due to the lack of taxonomic expertise in some regions and can become time‐consuming. In this study, we evaluated the feasibility of DNA barcoding for the classification of benthic macroinvertebrates and investigated the genetic differentiation in seven orders (Insecta: Ephemeroptera, Plecoptera, Trichoptera, Diptera, Hemiptera, Coleoptera, and Odonata) from four large transboundary rivers of northwest China and further explored its potential application to biodiversity assessment. A total of 1,144 COI sequences, belonging to 176 species, 112 genera, and 53 families were obtained and analyzed. The barcoding gap analysis showed that COI gene fragment yielded significant intra‐ and interspecific divergences and obvious barcoding gaps. NJ phylogenetic trees showed that all species group into monophyletic species clusters whether from the same population or not, except two species (Polypedilum. laetum and Polypedilum. bullum). The distance‐based (ABGD) and tree‐based (PTP and MPTP) methods were utilized for grouping specimens into Operational Taxonomic Units (OTUs) and delimiting species. The ABGD, PTP, and MPTP analysis were divided into 177 (p = .0599), 197, and 195 OTUs, respectively. The BIN analysis generated 186 different BINs. Overall, our study showed that DNA barcoding offers an effective framework for macroinvertebrate species identification and sheds new light on the biodiversity assessment of local macroinvertebrates. Also, the construction of DNA barcode reference library of benthic macroinvertebrates in Eurasian transboundary rivers provides a solid backup for bioassessment studies of freshwater habitats using modern high‐throughput technologies in the near future.