为了解武夷山国家公园大安源地区主要种群在群落中的关系及其相对地位,通过定量分析法,以生态位宽度、生态位重叠度、生态位相似性等为指标,开展武夷山国家公园大安源甜槠(Castanopsis eyrei)群落主要种群生态位研究,探讨各种群对环境资源的利用状况及相互功能关系以及主要种群的生态位特征等生态特点.结果表明,甜槠的重要值和生态位宽度值最大,具有最强的竞争能力和生态适应能力,为乔木林冠层的优势种;生态位相似性比例(Cih)在0.6以上的占了74.29％,表明该群落物种利用资源相似程度很大;生态位重叠指数Lih和Lhi大于0.5的种对分别有78和97对,分布比例分别为74.28％和92.38％,生态位重叠程度很高,各种群对资源的共享趋势较为明显.研究结果可为武夷山国家公园大安源群落生物多样性监测及保护提供参考依据.
为了探索大蒜根系分泌物主要成分(邻苯二甲酸二丁酯、二烯丙基二硫和2,6-二叔丁基对甲酚)及其混合物对烟蚜(Myzus persicae)的忌避、毒杀作用及其解毒酶影响.采用叶碟法测定了3种成分及其混配对烟蚜的忌避、触杀活性影响,采用ELISA检测试剂盒测定了其对烟蚜解毒酶的影响.结果表明,邻苯二甲酸二丁酯、二烯丙基二硫单独使用,对烟蚜的忌避效果显著(P＜0.05).在12 h内,体积比为1∶10时,二烯丙基二硫和邻苯二甲酸二丁酯对烟蚜的忌避活性较高,其对烟蚜最高忌避率分别达到97.98％和87.50％;在48 h内,体积比为1:10时,3种试剂单独使用,对烟蚜的触杀效果也显著(P＜0.05),其校正死率都在92.2％以上.当3种试剂同时混配时,比试剂单独使用对烟蚜有更显著的忌避活性(P＜0.05)和触杀活性(P＜0.05),忌避率81.96％～94.84％,校正死亡率95.14％～98.60％.3种试剂对烟蚜的解毒酶活性为:乙酰胆碱酯酶＞羧酸酯酶＞谷胱甘肽S-转移酶.研究结果可为研制含有该混合物试剂控制烟蚜及其对烟蚜控制作用提供科学参考.
Bacterial infections, especially multi-drug resistant bacterial infections, are one of the major problems in current clinical treatments. What is more, bacterial resistance is also becoming more and more serious, leading to the limited availability of effective drugs and treatment methods. As a new type of porous crystalline material, metal-organic frameworks（MOFs） represent promising materials to deal with the above problems; they can serve as effective antibacterial agents by releasing their own antibacterial components, producing reactive oxygen species, and loading antibacterial agents. Herein, we review the antibacterial mechanism, antibacterial applications, and potential cytotoxicity of MOFs. First, we summarize the main antibacterial mechanisms of MOFs, including the release of metal ions and organic ligands and induction of oxidative stress. Then, we emphatically introduce MOF materials used as antibacterial agents or solid carriers for loading antibacterial agents for use in the antibacterial field. Finally, we summarize the potential cytotoxicity of MOFs, point out the current challenges that need to be solved, and prospect the future development of MOF-based antibacterial agents.
Alysiini is an important parasitic insect, which is widely distributed throughout the world. As of the end of November 2022, 31 genera and 248 species have been catalogued in China, accounting for 39.24% and 14.87% of the world’s known genera and species, respectively. 92 species of Alysiini are endemic to China, accounting for 37.10% of all Alysiini species found in China. China straddles the Palaearctic and Oriental regions. We studied the geographical distribution of Alysiini and found that the common genera-level distribution type of Palaearctic and Oriental regions is most abundant, with 15 genera and 51 species. The second-most abundant is the endemic distribution type of the Oriental region, with 11 genera and 114 species. Only 5 genera are found in the Palaearctic region, comprising 83 species, which is rather rich. Known hosts of Alysiini include 5 orders, 49 families, and 137 genera. This survey information is essential for biological pest control applications.
The national trees of 80 countries are explained from the perspective of stamps to reveal their scientific connotations, humanistic implications, and ecological civilization. Diverse meanings of cultural tradition, national emotion, historical memory, and even the integration of civilization, can be discerned from national tree stamps.
