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1. chinaXiv:202006.00244 [pdf]

Relationship between ecological stoichiometry and plant community diversity in the upper reaches of Tarim River, northwestern China

ZHAO Jingjing; GONG Lu; CHEN Xin
Subjects: Geosciences >> History of Geosciences

Changes in ecological stoichiometry reflect nitrogen (N), phosphorus (P) and both N and P limitations in a plant community, which in turn affect plant diversity of the community. However, the relationship between plant community diversity and ecological stoichiometry has not yet been fully researched in arid and semi-arid regions. Ecological stoichiometry and plant community diversity indices of eighteen communities in the upper reaches of Tarim River, northwestern China, were analyzed by multivariate analysis of variance in 2016. The correlation between ecological stoichiometry and plant community diversity was assessed by redundancy analysis (RDA). Results indicated that the Margalef index was significantly correlated with carbon (C) and P concentrations, the Simpson index and Shannon–Weaner index were significantly correlated with plant C concentration, and the Pielou index was significantly correlated with plant C and N concentrations. Moreover, C:N and C:P ratios had significant impacts on plant community diversity. Our results highlight the importance of ecological stoichiometry in driving plant community diversity in the upper reaches of Tarim River, northwestern China.

submitted time 2020-06-22 From cooperative journals:《Journal of Arid Land》 Hits1193Downloads688 Comment 0

2. chinaXiv:201605.00770 [pdf]

Tc-99m-Cyclopentadienyl Tricarbonyl Chelate-Labeled Compounds as Selective Sigma-2 Receptor Ligands for Tumor Imaging

Li, Dan; Chen, Yuanyuan; Wang, Xia; Chen, Xin; Liu, Boli; Jia, Hongmei; Deuther-Conrad, Winnie; Steinbach, Joerg; Brust, Peter; Jia, Bing; Dong, Chengyan;
Subjects: Biology >> Biophysics

We have designed and synthesized a series of cyclopentadienyl tricarbonyl rhenium complexes containing a 5,6-dimethoxyisoindoline or a 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline pharmacophore as sigma(2) receptor ligands. Rhenium compound 20a possessed low nanomolar sigma(2) receptor affinity (K-i = 2.97 nM) and moderate subtype selectivity (10-fold). Moreover, it showed high selectivity toward vesicular acetylcholine transporter (2374-fold), dopamine D-2L receptor, NMDA receptor, opiate receptor, dopamine transporter, norepinephrine transporter, and serotonin transporter. Its corresponding radiotracer [Tc-99m]20b showed high uptake in a time- and dose-dependent manner in DU145 prostate cells and C6 glioma cells. In addition, this tracer exhibited high tumor uptake (5.92% ID/g at 240 min) and high tumor/blood and tumor/muscle ratios (21 and 16 at 240 min, respectively) as well as specific binding to sigma receptors in nude mice bearing C6 glioma xenografts. Small animal SPECT/CT imaging of [Tc-99m]20b in the C6 glioma xenograft model demonstrated a clear visualization of the tumor at 180 min after injection.

submitted time 2016-05-05 Hits1336Downloads817 Comment 0

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