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《Bioorganic & medicinal chemistry》2020,28(9):115437
NDM-1 can hydrolyze nearly all available β-lactam antibiotics, including carbapenems. NDM-1 producing bacterial strains are worldwide threats. It is still very challenging to find a potent NDM-1 inhibitor for clinical use. In our study, we used a metal-binding pharmacophore (MBP) enriched virtual fragment library to screen NDM-1 hits. SPR screening helped to verify the MBP virtual hits and identified a new NDM-1 binder and weak inhibitor A1. A solution NMR study of 15N-labeled NDM-1 showed that A1 disturbed all three residues coordinating the second zinc ion (Zn2) in the active pocket of NDM-1. The perturbation only happened in the presence of zinc ion, indicating that A1 bound to Zn2. Based on the scaffold of A1, we designed and synthesized a series of NDM-1 inhibitors. Several compounds showed synergistic antibacterial activity with meropenem against NDM-1 producing K. pneumoniae. 相似文献
3.
《Saudi Journal of Biological Sciences》2017,24(2):389-398
During the last decade many electronic databases of vegetation plots were established in many countries around the world. These databases contain valuable phytosociological information assisting both governmental and NGO (Non-governmental organizations) agencies to formulate strategies and on-ground plans to manage and protect nature resources. This paper provides an account on aims, current status and perspectives of building of a vegetation database for the Central Region (Najd) of Saudi Arabia – the founding element of the Saudi Vegetation Database (SVD). The data stored by the database are sample plots (vegetation relevés) collected according to the field techniques of the Braun-Blanquet approach (lists of taxa accompanied by semi-quantitative cover assessment), and are accompanied by general vegetation characteristics such as vegetation layering and cover, information on life-form of the recorded species, geographical coordinates, altitude, soil typology, topography and many more. More than 2900 vegetation-plot records (relevés) have so far been collected in the Najd region; of these more than 2000 have already been stored using the Turboveg database platform. These field records cover many habitats such as depressions, wadis (dry river beds), agricultural lands, sand dunes, sabkhas, and ruderal habitats. The ecological information collected in the database is currently the largest set of vegetation data collated into a database in the Middle East. These data are of great importance for biodiversity studies in Saudi Arabia, since the region is recording a loss of biodiversity at a fast rate due to environmental problems such as global warming and land-use changes. We envisage that this database would catalyze further data collection on vegetation of the entire Arabian Peninsula, and shall serve as one of the most important datasets for classification and mapping of the vegetation of the Kingdom of Saudi Arabia. 相似文献
4.
Uses and Conservation of Plant Species in a National Park—A Case Study of Ben En, Vietnam. This paper surveys the use of wild and cultivated plants by local people in Ben En National Park, Vietnam, and analyzes its
impact on the conservation status of some of the utilized species. A total of 208 species used for a range of nonmedicinal
purposes are listed. See Hoang et al. (2008a) for 230 medicinal plants used in the park. Most species are used for food. The use of plants contributes very significantly
to the livelihood of local people in the park, but the current use patterns are not sustainable and would lead to local extinction
of rare and endangered species if no additional conservation measures are introduced. Men collect nonmedicinal plants more
often than women. A total of 38 useful plant species are commercialized, and contribute 12% of the average income of individual
households. Bamboo shoots of Schizostachyum funghomii (Poaceae) are the most important for income generation. The monetary equivalent of noncommercialized useful plants probably
far exceeds the value of the traded plant products. Plant use is independent of the ethnicity of the different populations
living in the park. Larger households make use of a greater variety of useful plant species than small families. Abundant
species in the forest have a higher use index (UI) than less common species. Out of the 208 useful species, as many as 27
were found to be endangered locally, many more than the 11 or 8 endangered species included in national or global red lists.
Currently, useful plants, especially important timber trees, are more abundant in the less disturbed parts of the park, far
away from the villages, indicating the pressures of illegal logging and harvesting near villages on the ecosystems. 相似文献
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周边区域湿地景观变化对洪河保护区涉禽栖息地的影响 总被引:4,自引:0,他引:4
以三江平原洪河国家级保护区及其周边3个农场为研究区域,利用GIS技术和栖息地评价模型方法,探讨了周边区域湿地景观变化对保护区内景观结构以及丹顶鹤、东方白鹳栖息地的影响。结果显示:(1)自1983年区域土地开发以来,周边区域湿地景观面积减少了63%,景观类型多样性趋于单一化;(2)保护区内湿地景观结构改变明显,类型多样性呈降低趋势,丹顶鹤和东方白鹳栖息地面积和空间分布均发生变化;(3)保护区与周边区域湿地景观连通度降低了70%,其结果严重改变了保护区与周边区域的景观生态联系,削弱了保护区原有湿地景观多样性和涉禽栖息地功能;(4)必须从景观尺度,恢复保护区周边一定面积的湿地景观结构,维持保护区与周边区域适当的景观生态联系,是有效管理和维护保护区可持续发展的最佳手段之一。 相似文献
8.
Chris A. M. van Swaay Piotr Nowicki Josef Settele Arco J. van Strien 《Biodiversity and Conservation》2008,17(14):3455-3469
Since the first Butterfly Monitoring Scheme in the UK started in the mid-1970s, butterfly monitoring in Europe has developed
in more than ten European countries. These schemes are aimed to assess regional and national trends in butterfly abundance
per species. We discuss strengths and weaknesses of methods used in these schemes and give examples of applications of the
data. A new development is to establish supra-national trends per species and multispecies indicators. Such indicators enable
to report against the target to halt biodiversity loss by 2010. Our preliminary European Grassland Butterfly Indicator shows
a decline of 50% between 1990 and 2005. We expect to develop a Grassland Butterfly Indicator with an improved coverage across
European countries. We see also good perspectives to develop a supra-national indicator for climate change as well as an indicator
for woodland butterflies. 相似文献
9.
The results of a detailed analysis of 100 supernumerary limbs generated by 180° ipsilateral rotation (on the same limb stump) of regeneration blastemas is presented. The limbs were analyzed in terms of their position of origin, frequency, cartilage structure by Victoria blue staining, and muscle structure by serial sections. Single, double, or triple supernumeraries can be produced at no unique position of origin, although the posterodorsal quadrant was preferred. Four classes of supernumerary limbs were generated by such operations—normal; double dorsal or double ventral; part normal/part mirror imaged; part normal/part inverted in approximately equal frequencies. After amputation of these supernumeraries the same muscle patterns are faithfully regenerated. A hypothesis to explain the production of these abnormal limbs is proposed based on the observed phenomenon of fusion of supernumerary blastemata, but their regenerative behaviour presents problems for current models of pattern formation. Similar results have been obtained with developing limb buds and the relation between development and regeneration is discussed. 相似文献
10.
Flow cytometry: rapid biochemical analysis of single cells 总被引:7,自引:0,他引:7
H S Kruth 《Analytical biochemistry》1982,125(2):225-242