34 research outputs found

    Advances and challenges in shale oil development: A critical review

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        Different from the conventional oil reservoirs, the primary storage space of shale is micro/nano pore networks. Moreover, the multiscale and multi-minerals characteristics of shale also attract increasing attentions from researchers. In this work, the advances and challenges in the development of shale oil are summarized from following aspects: phase behavior, flow mechanisms, reservoir numerical simulation and production optimization. The phase behavior of fluids confined in shale nanopores are discussed on the basis of theoretical calculations, experiments, and molecular simulations. The fluid transport mechanisms through shale matrix are analyzed in terms of molecular dynamics, pore scale simulations, and experimental studies. The methods employed in fracture propagation simulation and production optimization of shale oil are also introduced. Clarifying the problems of current research and the need for future studies are conducive to promoting the scientific and effective development of shale oil resources.Cited as: Feng, Q., Xu, S., Xing, X., Zhang, W., Wang, S. Advances and challenges in shale oil development: A critical review. Advances in Geo-Energy Research, 2020, 4(4), 406-418, doi: 10.46690/ager.2020.04.0

    Mitochondrial genome organization varies among different groups of the booklouse, Liposcelis bostrychophila: Poster

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    The booklouse, Liposcelis bostrychophila is an important stored pest worldwide. The mt genome of an asexual strain (Beibei, China) of the booklouse, L. bostrychophila, comprises two chromosomes; each chromosome contains approximate half of the 37 genes typically found in animals. The mt genomes of two sexual strains of L. bostrychophila, however, comprise five and seven chromosomes respectively; each chromosome contains one to six genes. To understand mt genome evolution in L. bostrychophila, we sequenced the mt genomes of six strains of asexual L. bostrychophila collected from different locations in China, Croatia and USA. The mt genomes of all of the six asexual strains of L. bostrychophila collected in China, Croatia and USA have two chromosomes. Phylogenetic analysis of mt genome sequences divided nine strains of L. bostrychophila into four groups. Each group has a distinct mt genome organization and substantial sequence divergence (48.7-87.4%) from other groups. Furthermore, the seven asexual strains of L. bostrychophila including the published Beibei strain are more closely related to two other species of booklice, L. paeta and L. sculptilis, than to the sexual strains of L. bostrychophila. Our results revealed highly divergent mt genomes in the booklouse, L. bostrychophila, and indicated that L. bostrychophila is a cryptic species.The booklouse, Liposcelis bostrychophila is an important stored pest worldwide. The mt genome of an asexual strain (Beibei, China) of the booklouse, L. bostrychophila, comprises two chromosomes; each chromosome contains approximate half of the 37 genes typically found in animals. The mt genomes of two sexual strains of L. bostrychophila, however, comprise five and seven chromosomes respectively; each chromosome contains one to six genes. To understand mt genome evolution in L. bostrychophila, we sequenced the mt genomes of six strains of asexual L. bostrychophila collected from different locations in China, Croatia and USA. The mt genomes of all of the six asexual strains of L. bostrychophila collected in China, Croatia and USA have two chromosomes. Phylogenetic analysis of mt genome sequences divided nine strains of L. bostrychophila into four groups. Each group has a distinct mt genome organization and substantial sequence divergence (48.7-87.4%) from other groups. Furthermore, the seven asexual strains of L. bostrychophila including the published Beibei strain are more closely related to two other species of booklice, L. paeta and L. sculptilis, than to the sexual strains of L. bostrychophila. Our results revealed highly divergent mt genomes in the booklouse, L. bostrychophila, and indicated that L. bostrychophila is a cryptic species

    Stimulation of hair growth by Tianma Gouteng decoction: Identifying mechanisms based on chemical analysis, systems biology approach, and experimental evaluation

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    Hair serves important physiological functions, including temperature regulation and scalp protection. However, excessive shedding not only impacts these functions but can also significantly affect mental health and quality of life. Tianma Gouteng decoction (TGD) is a traditional Chinese medicine used for the treatment of various conditions, including hair loss. However, the associated mechanism underlying its anti-alopecia effect remains unknown. Therefore, this study aims to elucidate these mechanisms by employing systematic biology approaches, as well as in vitro and in vivo experimental validation. The chemical constituents of Tianma Gouteng decoction were identified using UHPLC-MS/MS, from which 39 potential bioactive components were screened, while an additional 131 putative Tianma Gouteng decoction beneficial components were extracted from the Traditional Chinese Medicine Database and Analysis Platform (TCMSP) database. We then applied a dual-dimensional network pharmacology approach to analyze the data, followed by validation studies combining molecular docking techniques with in vivo and in vitro experiments. From the 39 bioactive components, including quercetin, luteolin, fisetin, wogonin, oroxylin A, boldine, tetrahydroalstonine, and galangin A, 782 corresponding targets were identified. In particular, GSK3β and β-catenin exhibited strong binding activity with the bioactive compounds. Hence, construction of a bioactive component-target network revealed that the mechanism underlying the anti-alopecia mechanism of Tianma Gouteng decoction primarily involved the Wnt/β-catenin signaling pathway. Moreover, C57BL/6J mice exhibited measurable improvements in hair follicle regeneration following treatment with Tianma Gouteng decoction. Additionally, β-catenin and p-GSK3β levels were upregulated, while GSK3β was downregulated in Tianma Gouteng decoction-treated animals and dermal papilla cells compared to control group. These in vivo and in vitro outcomes validated the targets and pathways predicted in the network pharmacology analysis of Tianma Gouteng decoction. This study provides a systematic analysis approach to identify the underlying anti-alopecia mechanisms of Tianma Gouteng decoction, further providing theoretical support for clinical assessment of Tianma Gouteng decoction

    Structural and mechanistic insights into the biosynthesis of CDP-archaeol in membranes

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    The divergence of archaea, bacteria and eukaryotes was a fundamental step in evolution. One marker of this event is a major difference in membrane lipid chemistry between these kingdoms. Whereas the membranes of bacteria and eukaryotes primarily consist of straight fatty acids ester-bonded to glycerol-3-phosphate, archaeal phospholipids consist of isoprenoid chains ether-bonded to glycerol-1-phosphate. Notably, the mechanisms underlying the biosynthesis of these lipids remain elusive. Here, we report the structure of the CDP-archaeol synthase (CarS) of Aeropyrum pernix (ApCarS) in the CTP- and Mg(2+)-bound state at a resolution of 2.4 Å. The enzyme comprises a transmembrane domain with five helices and cytoplasmic loops that together form a large charged cavity providing a binding site for CTP. Identification of the binding location of CTP and Mg(2+) enabled modeling of the specific lipophilic substrate-binding site, which was supported by site-directed mutagenesis, substrate-binding affinity analyses, and enzyme assays. We propose that archaeol binds within two hydrophobic membrane-embedded grooves formed by the flexible transmembrane helix 5 (TM5), together with TM1 and TM4. Collectively, structural comparisons and analyses, combined with functional studies, not only elucidated the mechanism governing the biosynthesis of phospholipids with ether-bonded isoprenoid chains by CTP transferase, but also provided insights into the evolution of this enzyme superfamily from archaea to bacteria and eukaryotes.Cell Research advance online publication 29 September 2017; doi:10.1038/cr.2017.122

    Light-Reinforced Key Intermediate for Anticoking To Boost Highly Durable Methane Dry Reforming over Single Atom Ni Active Sites on CeO<sub>2</sub>.

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    Dry reforming of methane (DRM) has been investigated for more than a century; the paramount stumbling block in its industrial application is the inevitable sintering of catalysts and excessive carbon emissions at high temperatures. However, the low-temperature DRM process still suffered from poor reactivity and severe catalyst deactivation from coking. Herein, we proposed a concept that highly durable DRM could be achieved at low temperatures via fabricating the active site integration with light irradiation. The active sites with Ni-O coordination (NiSA/CeO2) and Ni-Ni coordination (NiNP/CeO2) on CeO2, respectively, were successfully constructed to obtain two targeted reaction paths that produced the key intermediate (CH3O*) for anticoking during DRM. In particular, the operando diffuse reflectance infrared Fourier transform spectroscopy coupling with steady-state isotopic transient kinetic analysis (operando DRIFTS-SSITKA) was utilized and successfully tracked the anticoking paths during the DRM process. It was found that the path from CH3* to CH3O* over NiSA/CeO2 was the key path for anticoking. Furthermore, the targeted reaction path from CH3* to CH3O* was reinforced by light irradiation during the DRM process. Hence, the NiSA/CeO2 catalyst exhibits excellent stability with negligible carbon deposition for 230 h under thermo-photo catalytic DRM at a low temperature of 472 °C, while NiNP/CeO2 shows apparent coke deposition behavior after 0.5 h in solely thermal-driven DRM. The findings are vital as they provide critical insights into the simultaneous achievement of low-temperature and anticoking DRM process through distinguishing and directionally regulating the key intermediate species
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