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荒漠草原(生态区)横贯我国西北地区东部,生态地位十分重要。近二十年来,通过封育禁牧、退耕还林(草),植被覆盖显著改善,但是生态系统质量和稳定性依然不高。由于长期将荒漠草原单纯视作草原的一部分,对其生态系统过渡性、脆弱性和复杂性本质特征认识不足,造成了荒漠草原生态学研究与区域生态建设实践之间不同程度的脱节。在分析荒漠草原生态区未来在我国生态安全格局中突出的但是被一定程度上忽视的地位的基础上,进一步归纳了荒漠草原生态系统的一般特征,指出了生态恢复与重建研究中存在的主要问题。进而以人工植被引入荒漠草原生态工程为案例,分析了人工植被驱动荒漠草原生态恢复与重建的过程与机制,归纳了“植被-水文-土壤”互馈作用驱动生态系统层级响应模式,并展望了今后的发展趋势与研究方向。 相似文献
43.
Zhizhong Dai Henry Lackland Stanley Stein Qian Li Robin Radziewicz Stephanie Williams Leonard H. Sigal 《生物化学与生物物理学报:疾病的分子基础》1993,1181(1):97-100
A monoclonal antibody (H9724), specific for the 41-kDa flagellar protein of the Lyme disease pathogen Borrelia burgdorferi, cross-reacts with human axons and detects one major protein in human neuroblastoma cell extracts. The homologous cross-reacting protein has now been isolated from calf adrenal and identified as chaperonin-HSP60 by N-terminal sequencing. 相似文献
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从四川省汶川县产平截独活Heracleum vicinum根的乙醇提取物中分离鉴定了6个成分,分别为虎耳草素(pimpinellin)(1),异佛手柑内酯(2),6-甲氧基当归素(sphondin)(3)。佛手柑内酯(bergapten)(4),异虎耳草素(isopimpincllin)(5),falcarindi01)(6). 相似文献
47.
To develop new highly effective anticancer agents derived from naturally occurring stilbene scaffold, in total of 24 indole and indazole-based stilbenes including 17 new compounds were designed according to molecular hybridization strategy and synthesized via Witting reaction. The cytotoxic screening results against human tumor cell lines (K562 cells and MDA-MB-231 cells) showed that indole and indazole-based stilbenes are of great interest for developing anticancer agents as eight derivatives possessed strong antiproliferative activities with IC50 values less than 10 μM, and those synthetic derivatives displayed more higher cytotoxicities against K562 cells than MDA-MB-231 cells. In particular, indole-based stilbene bearing piperidine exhibited the most potent cytotoxicities against both K562 and MDA-MB-231 cells with IC50 values 2.4 μM and 2.18 μM, respectively, along with a remarkable selectivity towards human normal L-02 cells. Together, the results suggested that indole and indazole-based stilbenes are promising anticancer scaffolds worthy of further investigation. 相似文献
48.
Nguyen Huy Hung Pham Minh Quan Do Ngoc Dai Prabodh Satyal Le Thi Huong Le Duc Giang Le Thanh Hung William N. Setzer 《化学与生物多样性》2023,20(3):e202200210
There is an ongoing interest to identify alternative pesticidal agents to avoid the chronic problems associated with synthetic pesticides. Essential oils have shown promise as botanical pest control agents. In the present study, the essential oils of four members of the Lamiaceae (Callicarpa candicans, C. erioclona, C. macrophylla, and Karomia fragrans; Vietnamese names: Nàng nàng, Tu châu lông mem, Tu châu lá to and Cà diện, respectively), obtained from wild populations in Vietnam, have been obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The essential oils were formulated into microemulsions and the essential oils and their microemulsions were screened for mosquito larvicidal activity against Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and for molluscicidal activity against Pomacea canaliculata. Atractylone and (E)-caryophyllene dominated the volatiles of C. candicans (CCEO) and C. erioclona (CEEO), while the major component in C. macrophylla (CMEO) and K. fragrans (KFEO) was (E)-caryophyllene. The essential oils and microemulsions of both C. candicans and C. erioclona exhibited excellent larvicidal activity against all three mosquito species (Ae. aegypti, Ae. albopictus, and Cx. quinquefasciatus) with LC50 values <10 μg/mL. Additionally, the larvicidal activity of the microemulsions were significantly improved compared with their free essential oils, especially for C. candicans and C. erioclona. All four essential oils and their microemulsions showed excellent molluscicidal activity with LC50 <10 μg/mL. In most cases, the essential oils and microemulsions showed greater pesticidal activity against target organisms than the non-target freshwater fish, Oreochromis niloticus. The in silico studies on physicochemical and ADMET properties of the major components in the studied essential oils were also investigated and most of the compounds possessed a favorable ADMET profile. Computational modeling studies of the studied compounds demonstrated a favorable binding interaction with the mosquito odorant-binding protein target and support atractylone, β-selinene, and caryophyllene oxide as potential inhibitors. Based on the observed pesticidal activities of the essential oils and their microemulsions, the Callicarpa species and K. fragrans should be considered for potential cultivation and further exploration as botanical pesticidal agents. 相似文献
49.
Xuebing Xu Tong Wu Renjie Lin Shengze Zhu Jie Ji Dandan Jin Mengxiang Huang Wenjie Zheng Wenkai Ni Feng Jiang Shihai Xuan Mingbing Xiao 《Journal of cellular and molecular medicine》2023,27(23):3672-3680
The migrasome is a new organelle discovered by Professor Yu Li in 2015. When cells migrate, the membranous organelles that appear at the end of the retraction fibres are migrasomes. With the migration of cells, the retraction fibres which connect migrasomes and cells finally break. The migrasomes detach from the cell and are released into the extracellular space or directly absorbed by the recipient cell. The cytoplasmic contents are first transported to the migrasome and then released from the cell through the migrasome. This release mechanism, which depends on cell migration, is named ‘migracytosis’. The main components of the migrasome are extracellular vesicles after they leave the cell, which are easy to remind people of the current hot topic of exosomes. Exosomes are extracellular vesicles wrapped by the lipid bimolecular layer. With extensive research, exosomes have solved many disease problems. This review summarizes the differences between migrasomes and exosomes in size, composition, property and function, extraction method and regulation mechanism for generation and release. At the same time, it also prospects for the current hotspot of migrasomes, hoping to provide literature support for further research on the generation and release mechanism of migrasomes and their clinical application in the future. 相似文献
50.
Xindong Xu Yifeng Wang Changhong Wang Gangqiang Guo Xinyu Yu Yang Dai Yaobao Liu Guiying Wei Xiaohui He Ge Jin Ziqiu Zhang Qingtian Guan Arnab Pain Shengyue Wang Wenbao Zhang Neil D. Young Robin B. Gasser Donald P. McManus Jun Cao Qi Zhou Qingfeng Zhang 《Molecular ecology resources》2023,23(1):205-221