Variations of sedimentary environment under cyclical aridification and impacts on eodiagenesis of tight sandstones from the late Middle Jurassic Shaximiao Formation in Central Sichuan Basin

Understanding eodiagenesis is essential to decoding the diagenetic pathways of tight sandstones that act as excellent unconventional oil & gas reservoirs. Great paleoclimate change is capable of influencing eodiagenetic processes of tight sandstones through variations of sedimentary environment. However, it is less noted how climate gradients between the greenhouse and the hothouse conditions impact the eodiagenesis of tight sandstones. We examined eodiagenetic processes that has been operated in the Shaximiao Formation sandstones using petrographic observation, scanning electron microscopy, geochemistry, and XRD analysis to reveal impacts of the transitional climate changes on the differential eodiagenesis and implications for the diagenesis-porosity evolution. Based on sequence stratigraphy, the Shaximiao Formation is divided into four sub-members SXM1, SXM2, SXM3, and SXM4, respectively. Dark sandstones and mudstones mainly occurred in the SXM1 and the SXM2. Grey-green clastic rocks are dominant in the SXM3, whereas red mudstones frequently appear in the SXM4. Paleoclimate indices denote that a cyclical aridification from the warm-humid to hot-semiarid conditions took place from the SXM1 to the SXM4. It could have been caused by the megamonsoon effect and the paleogeographic shift along with the breakup of the Pangaea supercontinent. Combined with the migration of depocenters, the paleoclimate change resulted in transformation of sediment provenances from mafic igneous rocks to quartzose sedimentary rock along with the decreasing textural maturity. Therefore, sedimentary environments varied from the high-saline to low-saline and from low-oxygen to high-oxygen conditions respectively, which had a crucial impact on eodiagenetic cements which were formed in the Shaximiao Formation. Chlorite and laumontite cement precipitation was promoted by high-saline alkaline fluids. Chlorite proportions show an arched trend from the SXM1 to the SXM4, compatible with those of primary and secondary porosities. In contrast, laumontite proportions exhibit a decreasing variation from the SXM1 to the SXM4. High percentages of early cements are favorable to improving resistance to the compaction and preservation of primary pores. However, high chlorite (>5%) and laumontite (>10%) proportions are destructive for the reservoir quality. Large quantities of laumontite cements occupy primary pores and impede diagenetic fluids flowing and are not favorable to the dissolution. By contrast, an excess of chlorite cements can be dissolved to produce secondary pores during the organic acid release. Thus, the SXM2 is potential as a reservoir for oil & gas. Therefore, those eodiagenetic cements can control the late diagenetic evolution and the reservoir quality. Observations made here have implications for understanding tight sandstone reservoirs elsewhere in the world

2D Black Phosphorus: from Preparation to Applications for Electrochemical Energy Storage

Black phosphorus (BP) is rediscovered as a 2D layered material. Since its first isolation in 2014, 2D BP has triggered tremendous interest in the fields of condensed matter physics, chemistry, and materials science. Given its unique puckered monolayer geometry, 2D BP displays many unprecedented properties and is being explored for use in numerous applications. The flexibility, large surface area, and good electric conductivity of 2D BP make it a promising electrode material for electrochemical energy storage devices (EESDs). Here, the experimental and theoretical progress of 2D BP is presented on the basis of its preparation methods. The structural and physiochemical properties, air instability, passivation, and EESD applications of 2D BP are discussed systemically. Specifically, the latest research findings on utilizing 2D BP in EESDs, such as lithium‐ion batteries, supercapacitors, and emerging technologies (lithium–sulfur batteries, magnesium‐ion batteries, and sodium‐ion batteries), are summarized. On the basis of the current progress, a few personal perspectives on the existing challenges and future research directions in this developing field are provided

Cross-Talk between Transcriptome Analysis and Dynamic Changes of Carbohydrates Identifies Stage-Specific Genes during the Flower Bud Differentiation Process of Chinese Cherry (<i>Prunus pseudocerasus</i> L.)

Flower bud differentiation is crucial to reproductive success in plants. In the present study, RNA-Seq and nutrients quantification were used to identify the stage-specific genes for flower bud differentiation with buds which characterize the marked change during flower bud formation from a widely grown Chinese cherry (Prunus pseudocerasus L.) cultivar ‘Manaohong’. A KEGG enrichment analysis revealed that the sugar metabolism pathways dynamically changed. The gradually decreasing trend in the contents of total sugar, soluble sugar and protein implies that the differentiation was an energy-consuming process. Changes in the contents of D-glucose and sorbitol were conformed with the gene expression trends of bglX and SORD, respectively, which at least partially reflects a key role of the two substances in the transition from physiological to morphological differentiation. Further, the WRKY and SBP families were also significantly differentially expressed during the vegetative-to-reproductive transition. In addition, floral meristem identity genes, e.g., AP1, AP3, PI, AGL6, SEP1, LFY, and UFO demonstrate involvement in the specification of the petal and stamen primordia, and FPF1 might promote the onset of morphological differentiation. Conclusively, the available evidence justifies the involvement of sugar metabolism in the flower bud differentiation of Chinese cherry, and the uncovered candidate genes are beneficial to further elucidate flower bud differentiation in cherries

Synthesis of nanoscale zero-valent iron doped carbonized zeolitic imidazolate framework-8 for methylene blue removal in water

Nanoscale zero-valent iron-doped carbonized zeolitic imidazolate framework-8 (nZVI/CZIF-8) was prepared by carbonation of ferric nitrate and ZIF-8 at 800 °C and used as an adsorbent to remove methylene blue (MB) from water. The synthesized nZVI/CZIF-8 has a specific surface area of 806.9 m2/g, a pore volume of 0.86 cm3/g and an nZVI content of 1.35%, respectively. Both the nZVI/CZIF-8 and CZIF-8 have identical functional groups of O-H, C-H and C=C. With the increase of CZIF-8 size, MB removal rate increased. The doping of nZVI increased the MB removal percentage from 74.5% for ZIF-8 to 96.2% within 80 min for nZVI/CZIF-8. The MB removal percentage increased with the dosage of nZVI/CZIF-8. The MB adsorption with the adsorbents conforms to the Freundlich adsorption isothermal model and the removal rate fitted well to a pseudo-first-order model. The results demonstrate the feasibility of synthesizing high active and stable nZVI/CZIF-8 particles

Overexpression of PavbHLH28 from Prunus avium enhances tolerance to cold stress in transgenic Arabidopsis

Abstract Background The basic helix-loop-helix (bHLH) gene family is one of plants’ largest transcription factor families. It plays an important role in regulating plant growth and abiotic stress response. Results In this study, we determined that the PavbHLH28 gene participated in cold resistance. The PavbHLH28 gene was located in the nucleus and could be induced by low temperature. Under the treatment of ABA, PEG, and GA3, the transcript level of PavbHLH28 was affected. At low temperature, overexpression of the PavbHLH28 gene enhanced the cold resistance of plants with higher proline content, lower electrolyte leakage (EL) and malondialdehyde (MDA) content. Compared with the WT plants, the transgenic plants accumulated fewer reactive oxygen species (ROS), and the activity and expression levels of antioxidant enzymes were significantly increased. The expression of proline synthesis enzyme genes was up-regulated, and the transcripts levels of degradation genes were significantly down-regulated. The transcripts abundance of the cold stressed-related genes in the C-repeat binding factor (CBF) pathway was not significantly different between WT plants and transgenic plants after cold stress. Moreover, the PavbHLH28 could directly bind to the POD2 gene promoter and promote its gene expression. Conclusions Overall, PavbHLH28 enhanced the cold resistance of transgenic plants through a CBF-independent pathway, which may be partly related to ROS scavenging

Sequencing and NHEJ alleles analysis of DsTdc2^CRISPR SWD.

(A) PCR products sequencing chromatograms of wild type (WT) SWD, microinjected G0, G1 heterozygotes DsTdc2CRISPR, and G2 resistant mutant at the gRNA1 target site. (B) NHEJ analysis of PCR products from G1 heterozygotes DsTdc2CRISPR, and G2 mutants at the gRNA1 and gRNA3 target sites. GRNA Target sites are indicated in green, PAM in yellow, and dashed lines represent the deleted bases. Letter N represent different types of NHEJ. The numbers on the right represent the count of base deletions. (TIF)</p

Sequencing and NHEJ alleles analysis of mutants mediated by <i>vasa</i>-Cas9(X).

(A) Heterozygous G1 master female mediated by vasa-Cas9(X) were sterile due to egg retention. (B) PCR product sequencing chromatograms of WT, heterozygous master G1 and G2 resistant mutant at the gRNA3 target site. (C) NHEJ analysis of PCR products from G2 resistant mutant of G1 master female mediated by vasa-Cas9(X) at three gRNA target sites. (D) Statistics of resistance alleles in G2 progeny (from two different males, left and right pie charts) mediated by vasa-Cas9(X). Specifically, 65 and 59 of their G2 progeny were sampled and analyzed. (TIF)</p

SGD systems targeting female essential gene <i>Tdc2</i> were constructed and validated in <i>D</i>. <i>melanogaster</i>.

(A) and (B) Schematic representation of the HDR knock-in construct of gene drive donor plasmid specifically recognizing DmTdc2 gene and the corresponding target locus. The plasmid contains homology arms of both ends of the cut site in order to act homology-directed repair, multi-gRNAs and Cas9 cassettes (with the ubiquitous promoter of hsp70 or Actin5C) to form fGD systems, and the marker construct (IE1-DsRed for red fluorescent body or 3×P3-DsRed for red fluorescent eyes) aiming to score the transgenic flies. (C) and (D) Outline of the genetic cross schemes used to demonstrate the driving efficiency of the sGD systems. The gene drive allele and Cas9 endonuclease gene are located in either different or same chromosomes. The conversion event at the sGD locus is shown with a yellow triangle in G1 individuals. (E) and (F) For DmTdc2hsp70 and DmTdc2Actin5C, G1 flies were separately single-pair mated to w1118 and assessed for inheritance of the gene drive construct. The introduced Cas9 protein was marked as +. Data analyzed using one-way ANOVA (P<0.0001) followed by Tukey’s multiple comparison tests (letters). Note that points marked as 0 drive inheritance represent drive flies that had no offspring.</p

Sequencing and NHEJ alleles analysis of mutants mediated by Act5C-Cas9(II).

(A) PCR products sequencing chromatograms of WT, heterozygous DmTdc2Actin5C, and G2 resistant mutant at the gRNA3 target site. (B) Statistics of resistance alleles in G2 progeny mediated by endogenous Act5C-Cas9(II). As for two DmTdc2Actin5C G1 males, 77 and 61 of their G2 offspring were randomly sampled and analyzed. And for two DmTdc2Actin5C G1 females, 34 of their G2 offspring were tested. (TIF)</p