分类： 环境科学技术及资源科学技术 >> 环境科学技术基础学科 提交时间： 2022-03-24 合作期刊: 《干旱区科学》
摘要： Abstract: Vegetation near-soil-surface factors can protect topsoil from erosion, however, their contributions to the reduction of soil erosion, especially under natural rainfall events, have not been systematically recognized. This study was performed to quantify the effects of near-soil-surface factors on runoff and sediment under natural rainfall events on grasslands dominated by Bothriochloa ischaemum (Linn.) Keng (BI grassland) and Artemisia gmelinii Thunb. (AG grassland) in two typical watersheds on the Loess Plateau, China in 2018. By successive removal of the plant canopy, litter, biological soil crusts (BSCs) and plant roots, we established five treatments including plant roots, plant roots+BSCs, plant roots+BSCs+litter, intact grassland and bare land in each grassland type. In total, twenty runoff plots (5 m3 m) with similar slopes and aspects were constructed in the two types of grasslands. Results showed that plant canopy, litter and roots reduced runoff, while BSCs, which swelled in the presence of water, increased runoff. In contrast, all of these factors reduced sediment yield. In addition, the reductions in runoff and sediment yield increased with I30 (maximum 30-min rainfall intensity) for each vegetation near-soil-surface factor except for BSCs. Among these factors, plant canopy had the largest contribution to runoff reduction, accounting for 48.8% and 39.9% in the BI and AG grasslands, respectively. The contributions of these vegetation near-soil-surface factors to sediment yield reduction were similar (21.3%29.9%) in the two types of grasslands except for BSCs in the AG grassland (10.3%). The total reduction in runoff in the BI grassland (70.8%) was greater than that in the AG grassland (53.1%), while the reduction in sediment yield was almost the same in both grasslands (97.4% and 96.7%). In conclusion, according to the effects of different vegetation near-soil-surface factors on runoff and sediment production, our results may provide more complete insight and scientific basis into the effects of various vegetation related factors in controlling soil erosion.
分类： 生物学 >> 病毒学 提交时间： 2020-02-25
Xia, Jia
Lu, Guoliang
Lu, Jing
Zhang, Jiahui
Feng, Lin
Wang, Bing
Yu, Hang
Xu, Yingjie
Lin, Jinzhong
摘要： Frequent outbreaks of coronavirus make the development of an effective vaccine imperative. Recently, vaccines based on in-vitro transcribed messenger RNA (mRNA) have shown great potential. The streamlined manufacturing of mRNA molecules, combined with the superior flexibility in the antigen screening, greatly accelerates the development process. When using an mRNA platform to develop a vaccine, initial antigen choice plays a crucial role in determining the final efficacy and safety of the vaccine. Furthermore, mRNA sequences that encode antigens require extensive optimization to ensure highly efficient and sustained expression. Our ongoing efforts to develop an effective mRNA vaccine against 2019-nCoV place emphasis on the virus-like particles (VLPs) as the presenting antigen. At the same time, our second fast track uses mRNA to express the receptor-binding domain of the spike protein(S-RBD). After extensive optimization, an mRNA cocktail containing three genes is able to produce 2019-nCoV virus-like particles highly similar to the native 2019-nCoV. Meanwhile, an mRNA vaccine candidate expressing S-RBD is being tested in mice for its immunogenicity. We will next compare both the efficacy and the safety of the two mRNA vaccines based on S-RBD and VLPs, respectively.
分类： 生物学 >> 生物医药 提交时间： 2017-05-10
Wang, Lan
Zhou, Guang-Biao
Liu, Ping
Song, Jun-Hong
Liang, Yang
Yan, Xiao-Jing
Xu, Fang
Wang, Bing-Shun
Mao, Jian-Hua
Shen, Zhi-Xiang
摘要： To enhance therapeutic efficacy and reduce adverse effects, practitioners of traditional Chinese medicine (TCM) prescribe a combination of plant species/minerals, called formulae, based on clinical experience. Nearly 100,000 formulae have been recorded, but the working mechanisms of most remain unknown. In trying to address the possible beneficial effects of formulae with current biomedical approaches, we use Realgar-Indigo naturalis formula (RIF), which has been proven to be very effective in treating human acute promyelocytic leukemia (APL) as a model. The main components of RIF are realgar, Indigo naturalis, and Salvia miltiorrhiza, with tetraarsenic tetrasulfide (A), indirubin (I), and tanshinone IIA (T) as major active ingredients, respectively. Here, we report that the ATI combination yields synergy in the treatment of a murine APL model in vivo and in the induction of APL cell differentiation in vitro. ATI causes intensified ubiquitination/degradation of promyelocytic leukemia (PML)-retinoic acid receptor #1; (RAR#1;) oncoprotein, stronger reprogramming of myeloid differentiation regulators, and enhanced G1/G0 arrest in APL cells through hitting multiple targets compared with the effects of mono- or biagents. Furthermore, ATI intensifies the expression of Aquaglyceroporin 9 and facilitates the transportation of A into APL cells, which in turn enhances A-mediated PML-RAR#1; degradation and therapeutic efficacy. Our data also indicate A as the principal component of the formula, whereas T and I serve as adjuvant ingredients. We therefore suggest that dissecting the mode of action of clinically effective formulae at the molecular, cellular, and organism levels may be a good strategy in exploring the value of traditional medicine.
点击量
点击量
下载量
评论
待评议
