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Alkali (high-pH) stress is an important factor limiting agricultural production and has complex effects on plant metabolism. Transcriptomics is widely used in the discovery of stress-response genes, but it provides only a rough estimation for gene expression. Proteomics may be more helpful than transcriptomics for the discovery and identification of stress-response genes. In this study, wheat plants were treated with sodic alkaline stress (50 mM, NaHCO 3 : Na 2 CO 3  = 1:1; pH 9.7), and then proteomic analysis was carried out on control and stressed plants. We detected 3,104 proteins, including 69 alkaline stress-response proteins. Five superoxide dismutases, three malate dehydrogenases, three dehydrin proteins, and one V-ATPase protein were upregulated in sodic alkaline-stressed wheat roots. We propose that these salinity response proteins may be important for ion homeostasis and osmotic regulation of sodic alkaline-stressed wheat. Additionally, two malic enzymes and many enzymes involved in the tricarboxylic acid cycle (TCA) were downregulated in the roots. The upregulation of malate dehydrogenase and the downregulation of TCA enzymes and malic enzymes may enhance the accumulation of malate in sodic alkaline-stressed wheat roots. Previous studies have demonstrated that the accumulation of malate in roots is a crucial adaptive mechanism of wheat to sodic alkaline stress. Herein, our proteomics results provided molecular insights into this adaptive mechanism., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Biomass-derived Cu/porous carbon (Cu/PC) composites were facilely assembled by using a one-pot hydrothermal approach combined with calcination under a N2 atmosphere, and were used for the electrocatalytic synthesis of cyclic carbonates from CO2 and diols at room temperature and normal pressure without any other catalysts. The results show that the Cu/PC composites with large specific surface areas (SBET > 279 m2 g−1) and high pore volumes (Vp > 0.47 cm3 g−1) possess good catalytic activity for CO2 electrocatalytic fixation. The Cu nanoparticles were uniformly dispersed in the PC, resulting in a remarkable increase in the catalytic activity of the composite compared with those of pure PC and Cu sheets. In addition, the Cu content influenced the electrocatalytic activity. Among the materials used, Cu/PC-III was the best cathode as it had a 46.3% electrosynthesis yield of propylene carbonate, wide application prospects and was suitable for the synthesis of other o-diols. The yield of 4-propyl-1,3-dioxolan-2-one reached 57.8%. The prepared composites also displayed satisfactory reusability, and the yield was not reduced even after six cycles of use. These results reveal that the composites could be effectively used for the electrosynthesis of cyclic carbonates from CO2 and diols under mild conditions. [ABSTRACT FROM AUTHOR]

Environmental scenarios around the Cenomanian-Turonian ocean anoxic event (OAE2) interval are scarcely studied in the southeastern Neo-Tethys and not discussed in terms of variation of primary mineralogies of marine carbonates. Based on petrological and geochemical analyses, this study focuses on the increased aragonite abundance in the oxygen-decreasing interval before the OAE2 and its environmental implications in the southeastern Neo-Tethys. In central Iraq, the upper Cenomanian-lower Turonian Mishrif Formation represents marine carbonate records in the southeastern, tropical Neo-Tethys and includes five members from the lowermost Mi-5 to the uppermost Mi-1. From Mi-5 to Mi-1, dominant carbonate components and primary carbonate mineralogies vary. Mi-5 is dominated by primarily calcitic grains (mainly calcite shells of rudists and echinoids); Mi-4 and Mi-3 dominated by primarily aragonitic grains (mainly green algae and aragonitic bivalves) and planktonic calcitic foraminifera; and Mi-1 dominated by primarily calcitic ooids. Paleoenvironmental interpretations suggest: i) open marine, offshore settings for Mi-5 to Mi-3, and a shallow marine shoal setting for Mi-1; ii) a sea level rise from Mi-5 to Mi-3, followed by a sea level fall to Mi-1. The increasing aragonite abundance in Mi-4 and Mi-3 is exceptional and suggested to most likely reflect enhanced preservation of shallow-marine aragonite transported into open marine offshore settings. This enhanced aragonite preservation is likely related to an oxygen-decreasing level before the OAE2 in the offshore settings. Remarkably, these primarily aragonitic components are commonly preserved now as moldic pores in Mi-4 and Mi-3. The moldic pores are interpreted to be produced via deep burial dissolution of recrystallized aragonitic grains, based on petrological and geochemical analyses. Moreover, the primary carbonate compositional and mineralogical changes from Mi-5 to Mi-1 provide some potential clues for the environmental scenarios around the OAE2 interval in the southeastern, tropical Neo-Tethys: i) from Mi-5 to Mi-4 and Mi-3, the increasing abundance of primarily aragonitic components is accompanied by a sea level rise, increasing seawater temperature and decreasing oxygen level of bottom water; ii) from Mi-3 to Mi-1, the decreasing abundance of primarily aragonitic components is accompanied by a sea level fall, decreasing seawater temperature and enhanced microbial carbonate production. [ABSTRACT FROM AUTHOR]

Wu, H.; Wang, G.H.; Ding, X.Z., and Wang, H., 2020. Geochemistry of the Neoproterozoic molar tooth carbonate in the Benxi Area, North China Craton: The paleo-ocean environment. In: Bai, X. and Zhou, H. (eds.), Advances in Water Resources, Environmental Protection, and Sustainable Development. Journal of Coastal Research, Special Issue No. 115, pp. 446-450. Coconut Creek (Florida), ISSN 0749-0208. Molar tooth carbonate is a special sedimentary rock, which has been widely found around the world, such as Europe, North America, Africa and Asia. The features and genesis of molar tooth carbonate are still the focus of the sedimentary study so far. The molar tooth carbonate has an important significant for the stratigraphic correlation, sedimentary condition and paleoenvironment. In the Benxi area, the discovery of the molar tooth carbonate in the Nanhua System has a great meaning to study the Precambrian geology of the Jiao-Liao Block, then reconstruct the Neoproterozoic paleogeography of North China Craton. In the last decade, the methods of geochemistry have been widely used to solve geological problems, for example petrogenesis, tectonic evolution, dynamics and so on. The main geochemistry method of carbonate is C-O isotope analysis, which can suggest the feature of ancient water temperature. It also can be used to identify the history of oxidation event or glaciation. There are some evidences show that molar tooth carbonate has relationship with oxidation event and glaciation. The oxidation event and glaciation can change and reflect the setting of paleo-ocean environment and then influence the diversity of marine lives. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the one-step synthesis of enantiomerically pure cyclic carbonates has been developed by electrolyzing the chiral epoxides and CO2 (0.1MPa, rt) in an undivided cell with a 316 stainless steel (SS) cathode and a Mg sacrificial anode containing TEAI–MeCN as supporting electrolyte and solvent with a constant current. To deeply understand this reaction, the effects of various synthesis conditions were investigated using R-styrene oxide as the model compound. Under the optimized conditions, the maximum conversion is 67% with 96% selectivity and 98.8% ee value for R-styrene carbonate. Finally, the reaction mechanism has been proposed by comparative electrolysis and DFT calculation. [Copyright &y& Elsevier]

[Display omitted] • Ten carbonate microfacies deposited in five sedimentary facies belts are identified in the Rumaila Formation. • Rapid sedimentary facies changes were organized into three RST and two TST caused by frequent relative sea-level changes. • Reservoir quality is related with carbonate microfacies types. • Differential early diagenesis causes distinct contrasts of pore evolution for the same primary rock texture. • Reservoir quality of the Rumaila is jointly controlled by sedimentary facies variation and differential early diagenesis. The Middle Cretaceous Rumaila Formation comprises a thick carbonate succession and forms an important reservoir unit in the Central Mesopotamian Basin. Microfacies analysis was performed based on the cores and thin sections observations to investigate the sedimentary and diagenesis evolution, and physical properties and mercury injection capillary pressure measurements were conducted to evaluate the reservoir quality. Ten microfacies types are identified showing that Rumaila carbonates deposited in five sedimentary facies belts: (i) platform-margin rudist shoals, (ii) platform interior grain shoals, (iii) platform interior inter-shoal, (iv) slope & toe-of-slope, and (v) deep shelf. These facies are organized into three regressive systems tracts and two transgressive systems tracts. Microfacies types present prominent vertical variations but are relatively stable in lateral extension, revealing a wide carbonate shelf sedimentary environment with frequent fluctuations of relative sea-levels. There is a good correlation between microfacies types and reservoir quality, ten microfacies types are classified as three classes with distinct reservoir quality. Thereinto, the microfacies rudist grainstone, bioclastic peloidal grainstone and worn rudist grainstone bear the best reservoir quality. The Rumaila Formation provides a typical case that reservoir quality and reservoir heterogeneity are jointly controlled by sedimentary facies variation caused by frequent relative sea-level changes, and differential early diagenesis. The frequent changes of relative sea-levels lead to the rapid changes of sedimentary facies (rock texture) and the frequently stacking of limestones with different primary porosity. Differential early diagenesis resulted in distinct contrasts of pore evolution for the same rock textures, which further enhance reservoir heterogeneity and also illustrate the destruction of cements on reservoir quality. This study provides an insight into reservoir quality prediction in the study area and other carbonate reservoirs undergone similar sedimentation and diagenesis process. [ABSTRACT FROM AUTHOR]

This study investigated the lithological, sedimentological and geochemical characteristics of Lower Jurassic strata (Ziliujing Formation) in the Sichuan Basin to identify the lithofacies and understand the depositional environments and differences in organic matter accumulation of these nonmarine fine-grained sediments. Based on mineralogy and petrology, rock types were recognized, with mudstones, siltstones, and limestones being the most common. Rock types, sedimentary structures, biota, and well log data were used to define and characterize 17 lithofacies and the following five facies associations of the fine-grained sediments: (1) delta front; (2) clastic lakeshore; (3) clastic shallow lake; (4) clastic semi-deep lake; and (5) carbonate lake. The content of total organic carbon ranges between 0.04% and 3.84%, with an average of 0.74%. The organic matter primarily consists of Type Ⅲ kerogen. Major processes inferred from the lithofacies analyses include suspension, biogenic, and storm deposition. On the basis of facies associations, redox, climate and salinity conditions, biotic productivity, and terrigenous input, a total of six depositional environments are proposed: (I) high-productivity low-oxygen swamp (II) low-oxygen semi-deep lake (III) high-oxygen semi-deep lake (IV) high-oxygen shallow lake (V) deep-water low-oxygen semi-deep lake and (VI) high-salinity low-oxygen shallow lake. The nonmarine environments changed frequently, unlike more stable environments. The development of bivalves in the shallow lake is suggested to be related to high salinity caused by dry climate, together with limited terrigenous input. Organic-rich nonmarine fine-grained sediments in the Ziliujing Formation formed in swamp and semi-deep lake with settings under reducing conditions, in a humid climate, with relatively high terrigenous input. Results of the study may help us to understand the deposition of nonmarine organic-rich fine-grained Lower Jurassic sediments in southwest, China. • A total of 17 lithofacies and five facies association were identified. • Major depositional processes include suspension, biogenic and storm depositions. • The nonmarine fine-grained rocks were deposited in six depositional environments. • The accumulation of organic matter is controlled by paleoenvironmental conditions. • The organic-rich sediments were mostly developed in swamp and semi-deep lake. [ABSTRACT FROM AUTHOR]