and acetic acid that yields the imidazolium salt, DBDFIM-Ac. Studies of the complete two-reaction process that uses furfural for the synthesis of DBDFIM-Ac showed that the highest yield of DBDFIM-Ac was obtained when the mole ratio of n-butylamine, formaldehyde, and acetic acid relative to furfural was respectively (0.5:0.25:0.25:1.0-furfural), or one-half of the stoichiometric ratio (1.0:0.5:0.5:1.0-furfural). A time course study of the process showed transient formation of furoin, the obligatory reaction intermediate. DBDFIM-Ac and the imidazolium side product, 1,3-dibutyl-4,5-trifuryl-imidazolium acetate (DBTFIM-Ac), were stable under the reaction conditions. Imidazolium products (DBDFIM and DBTFIM) and the furoin intermediate were not formed in control reactions (80 °C, 24 h) in which EMIM catalyst was either absent or replaced with an equal volume of acetonitrile or DMF. The imidazolium product, DBDFIM-Ac, was shown to catalyze the synthesis of structurally similar 1,3-dipentyl-4,5-difuryl-imidazolium acetate (DPDFIM-Ac) from furfural, n- pentylamine, formaldehyde, and acetic acid at 80 °C.

Wei, S., Han, G., Chu, X., Song, W., He, W., Xia, J., Wu, H., 2020. Effect of tidal flooding on ecosystem CO and 2 CH fluxes in a salt marsh in the Yellow River Delta. Estuarine, Coastal and Shelf Science 232, 106512. 4

http://www.sciencedirect.com/science/article/pii/S0272771419304767 Tidal flooding is the basic hydrological feature of a salt marsh, and controls its ecosystem carbon exchange. However, the response of ecosystem carbon exchange to different stages of tidal flooding remains poorly documented. To further explore this issue, we conducted a field experiment to assess the effect of tidal stages (before flooding stage, rising tide stage, tidal flooding stage and after ebbing stage), water levels (a control, a low water level (LWL), a middle water level (MWL) and a high water level (HWL)) and soil salinity on ecosystem CO and CH fluxes in a salt marsh in the Yellow River Delta. Our results showed that the rising tide 2 4 - 2 - 1 - 2 stage significantly inhibited the uptake of CO (LWL: 1.49 ± 0.23 μmol m s ; MWL: 1.10 ± 0.35 μmol m 2 - 1 - 2 - 1 s ; HWL: 0.54 ± 0.08 μmol m s ). Meanwhile, the rising tide stage also promoted CH emissions of MWL 4 - 2 - 1 - 2 - 1 and HWLtreatments (MWL: 0.97 ± 0.36 nmol m s ; HWL: 0.93 ± 0.24 nmol m s ). CH emissions of the 4 after ebbing stage was higher than that of the before flooding stage, and this difference was significant of LWL - 2 - 1 and MWLtreatments (LWL: 0.56 ± 0.12 vs 0.38 ± 0.09 nmol m s ; MWL: 0.79 ± 0.13 vs 0.40 ± 0.09 nmol - 2 - 1 m s ). Moreover, ecosystem CO exchange of the HWLtreatment was almost completely suppressed during 2 tidal inundation period. During tidal inundation period, net ecosystem CO exchange (NEE) was significantly 2 positively correlated with water levels, but CH emissions was not significantly affected by water levels. In 4 addition, the rate of CO uptake decreased linearly with soil salinity during the non-inundation period. 2 Therefore, it is necessary to analyze the carbon exchange process coupling with the complete tidal flooding process in future researches.

Wendruff, A.J., Babcock, L.E., Wirkner, C.S., Kluessendorf, J., Mikulic, D.G., 2020. A Silurian ancestral scorpion with fossilised internal anatomy illustrating a pathway to arachnid terrestrialisation. Scientific Reports 10, 14.

https://doi.org/10.1038/s41598-019-56010-z Scorpions are among the first animals to have become fully terrestrialised. Their early fossil record is limited, and fundamental questions, including how and when they adapted to life on land, have been difficult to answer. Here we describe a new exceptionally preserved fossil scorpion from the Waukesha Biota (early Silurian, ca. 437.5 -436.5 Ma) of Wisconsin, USA. This is the earliest scorpion yet reported, and it shows a combination of primitive marine chelicerate and derived arachnid characteristics. Elements of the circulatory, respiratory, and digestive systems are preserved, and they are essentially indistinguishable from those of present-day scorpions but share similarities with marine relatives. At this early point in arachnid evolution, physiological changes concomitant with the marine-to-terrestrial transition must have occurred but, remarkably, structural change in the circulatory or respiratory systems appear negligible. Whereas there is no unambiguous evidence that this early scorpion was terrestrial, this evidence suggests that ancestral scorpions were likely capable of forays onto land, a behavior similar to that of extant horseshoe crabs.

Williams, T.A., Cox, C.J., Foster, P.G., Szöllősi, G.J., Embley, T.M., 2020. Phylogenomics provides robust support for a two-domains tree of life. Nature Ecology & Evolution 4, 138-147.