Summary
Plant protoplasts are useful for assessing the efficiency of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR‐associated protein 9 (Cas9) mutagenesis. We improved the ...process of protoplast isolation and transfection of several plant species. We also developed a method to isolate and regenerate single mutagenized Nicotianna tabacum protoplasts into mature plants. Following transfection of protoplasts with constructs encoding Cas9 and sgRNAs, target gene DNA could be amplified for further analysis to determine mutagenesis efficiency. We investigated N. tabacum protoplasts and derived regenerated plants for targeted mutagenesis of the phytoene desaturase (NtPDS) gene. Genotyping of albino regenerants indicated that all four NtPDS alleles were mutated in amphidiploid tobacco, and no Cas9 DNA could be detected in most regenerated plants.
The North China Craton (NCC) was originally formed by the amalgamation of the eastern and western blocks along an orogenic belt at ∼1.9 Ga. After cratonization, the NCC was essentially stable until ...the Mesozoic, when intense felsic magmatism and related mineralization, deformation, pull-apart basins, and exhumation of the deep crust widely occurred, indicative of destruction or decratonization. Accompanying this destruction was significant removal of the cratonic keel and lithospheric transformation, whereby the thick (∼200 km) and refractory Archean lithosphere mantle was replaced by a thin (<80 km) juvenile one. The decratonization of the NCC was driven by flat slab subduction, followed by a rollback of the paleo-Pacific plate during the late Mesozoic. A global synthesis indicates that cratons are mainly destroyed by oceanic subduction, although mantle plumes might also trigger lithospheric thinning through thermal erosion. Widespread crust-derived felsic magmatism and large-scale ductile deformation can be regarded as petrological and structural indicators of craton destruction.
A craton, a kind of ancient continental block on Earth, was formed mostly in the early Precambrian (>1.8 Ga).
A craton is characterized by a rigid lithospheric root, which provides longevity and stability during its evolutionary history.
Some cratons, such as the North China Craton, can be destroyed by losing their stability, manifested by magmatism, deformation, earthquake, etc.
A comprehensive immune landscape for HBV infection is pivotal to achieve HBV cure.
We performed single-cell RNA sequencing of 2 43 000 cells from 46 paired liver and blood samples of 23 individuals, ...including six immune tolerant, 5 immune active (IA), 3 acute recovery (AR), 3 chronic resolved and 6 HBV-free healthy controls (HCs). Flow cytometry and histological assays were applied in a second HBV cohort for validation.
Both IA and AR were characterised by high levels of intrahepatic exhausted CD8+ T (Tex) cells. In IA, Tex cells were mainly derived from liver-resident GZMK+ effector memory T cells and self-expansion. By contrast, peripheral CX3CR1+ effector T cells and GZMK+ effector memory T cells were the main source of Tex cells in AR. In IA but not AR, significant cell-cell interactions were observed between Tex cells and regulatory CD4+ T cells, as well as between Tex and FCGR3A+ macrophages. Such interactions were potentially mediated through human leukocyte antigen class I molecules together with their receptors CANX and LILRBs, respectively, contributing to the dysfunction of antiviral immune responses. By contrast, CX3CR1+GNLY+ central memory CD8+ T cells were concurrently expanded in both liver and blood of AR, providing a potential surrogate marker for viral resolution. In clinic, intrahepatic Tex cells were positively correlated with serum alanine aminotransferase levels and histological grading scores.
Our study dissects the coordinated immune responses for different HBV infection phases and provides a rich resource for fully understanding immunopathogenesis and developing effective therapeutic strategies.
Most mono- and co-culture bioprocess applications rely on large-scale suspension fermentation technologies that are not easily portable, reusable, or suitable for on-demand production. Here, we ...describe a hydrogel system for harnessing the bioactivity of embedded microbes for on-demand small molecule and peptide production in microbial mono-culture and consortia. This platform bypasses the challenges of engineering a multi-organism consortia by utilizing a temperature-responsive, shear-thinning hydrogel to compartmentalize organisms into polymeric hydrogels that control the final consortium composition and dynamics without the need for synthetic control of mutualism. We demonstrate that these hydrogels provide protection from preservation techniques (including lyophilization) and can sustain metabolic function for over 1 year of repeated use. This approach was utilized for the production of four chemical compounds, a peptide antibiotic, and carbohydrate catabolism by using either mono-cultures or co-cultures. The printed microbe-laden hydrogel constructs' efficiency in repeated production phases, both pre- and post-preservation, outperforms liquid culture.
Oleanolic acid (OA) is a triterpenoid that exists widely in fruits, vegetables and medicinal herbs. OA is included in some dietary supplements and is used as a complementary and alternative medicine ...(CAM) in China, India, Asia, the USA and European countries. OA is effective in protecting against various hepatotoxicants, and one of the protective mechanisms is reprogramming the liver to activate the nuclear factor erythroid 2‐related factor 2 (Nrf2). OA derivatives, such as CDDO‐Im and CDDO‐Me, are even more potent Nrf2 activators. OA has recently been shown to also activate the Takeda G‐protein‐coupled receptor (TGR5). However, whereas a low dose of OA is hepatoprotective, higher doses and long‐term use of OA can produce liver injury, characterized by cholestasis. This paradoxical hepatotoxic effect occurs not only for OA, but also for other OA‐type triterpenoids. Dose and length of time of OA exposure differentiate the ability of OA to produce hepatoprotection vs hepatotoxicity. Hepatotoxicity produced by herbs is increasingly recognized and is of global concern. Given the appealing nature of OA in dietary supplements and its use as an alternative medicine around the world, as well as the development of OA derivatives (CDDO‐Im and CDDO‐Me) as therapeutics, it is important to understand not only that they program the liver to protect against hepatotoxic chemicals, but also how they produce hepatotoxicity.
Plant metabolism, including primary metabolism such as tricarboxylic acid cycle, glycolysis, shikimate and amino acid pathways as well as specialized metabolism such as biosynthesis of phenolics, ...alkaloids and saponins, contributes to plant survival, growth, development and interactions with the environment. To this end, these metabolic processes are tightly and finely regulated transcriptionally, post-transcriptionally, translationally and post-translationally in response to different growth and developmental stages as well as the constantly changing environment. In this review, we summarize and describe the current knowledge of the regulation of plant metabolism by alternative splicing, a post-transcriptional regulatory mechanism that generates multiple protein isoforms from a single gene by using alternative splice sites during splicing. Numerous genes in plant metabolism have been shown to be alternatively spliced under different developmental stages and stress conditions. In particular, alternative splicing serves as a regulatory mechanism to fine-tune plant metabolism by altering biochemical activities, interaction and subcellular localization of proteins encoded by splice isoforms of various genes.
Gold nanoclusters with surface open sites are crucial for practical applications in catalysis. We have developed a surface geometric mismatch strategy by using mixed ligands of different type of ...hindrance. When bulky phosphine Ph3P and planar dipyridyl amine (Hdpa) are simultaneously used, steric repulsion between the ligands will reduce the ligand coverage of gold clusters. A well‐defined access granted gold nanocluster Au23(Ph3P)10(dpa)2Cl(SO3CF3)2 (Au23, dpa=dipyridylamido) has been successfully synthesized. Single crystal structural determination reveals that Au23 has eight uncoordinated gold atoms in the shape of a distorted bicapped triangular prism. The accessibility of the exposed Au atoms has been confirmed quantitatively by luminescent titration with 2‐naphthalenethiol. This cluster has excellent performance toward selective oxidation of benzyl alcohol to benzaldehyde and demonstrates excellent stability due to the protection of negatively charged multidentate ligand dpa.
A stable Au23 nanocluster with preorganized open sites has been conducted through surface geometric mismatch strategy. The 35 % accessibility of Au23 was confirmed by luminescent titration with 2‐naphthalenethiol. The preorganized open sites make intact Au23 a high‐performance catalyst for aerobic oxidation of benzyl alcohol.
Abstract
Magnetohydrodynamic (MHD) turbulence is an important agent of energetic particle acceleration. Focusing on the compressible properties of magnetic turbulence, we adopt the test particle ...method to study the particle acceleration from Alfvén, slow, and fast modes in four turbulence regimes that may appear in a realistic astrophysical environment. Our studies show that (1) the second-order Fermi mechanism drives the acceleration of particles in the cascade processes of three modes by particle-turbulence interactions, regardless of whether the shock wave appears; (2) not only can the power spectra of maximum-acceleration rates reveal the inertial range of compressible turbulence, but also recover the scaling and energy ratio relationship between the modes; (3) fast mode dominates the acceleration of particles, especially in the case of super-Alfvénic and supersonic turbulence, slow mode dominates the acceleration for sub-Alfvénic turbulence in the very-high-energy range, and the acceleration of Alfvén mode is significant at the early stage of the acceleration; (4) particle acceleration from three modes results in a power-law distribution in the certain range of evolution time. From the perspective of particle-wave mode interaction, this paper promotes the understanding for both the properties of turbulence and the behavior of particle acceleration, which will help provide insight into astrophysical processes involved in MHD turbulence.
WS2 anode materials show huge potential for fast‐charging lithium‐ion batteries (LIBs) due to the naturally good 2D diffusion pathways but suffer from large Li+ diffusion barrier energy and poor ...intrinsic electrical conductivity. Here, a defect‐rich atomic‐scale laminated structure of WS2 and C (D‐WS2‐C) with O doping and enlarged interlayer distance from 0.62 to 1.06 nm of WS2 is first fabricated, which is assembled into micron‐sized spheres to prepare WS2/C composite microspheres. D‐WS2‐C with maximized molecular layer contact area between WS2 and carbon and large interlayer spacing greatly enhances the electrical conductivity of WS2 and reduces Li‐ion diffusion energy barrier, confirmed by density functional theory calculations. Besides, the unique D‐WS2‐C enables the formation of vast superfine W nanoparticles (1–2 nm) during the conversation reaction, resulting in the construction of a space charge zone on W surface. Based on these characteristics of D‐WS2‐C, the prepared WS2/C composite microspheres show superior fast‐charging capability with a high capacity of 647.8 mAh g−1 at 20 C in half cells. For full cells, a high‐energy density of 100.9 Wh kg−1 is achieved at a charge time of only 8.5 min at 5 C, representing the best fast‐charging performances in WS2‐based anode materials to date.
Exploiting fast‐charging lithium‐ion‐battery anode materials is considered a prerequisite to meet the continually increasing requirements of the rapid development of portable electronic devices and electric vehicles. This work reports an advanced defect‐rich atomic‐scale laminated structure of WS2 and C with O doping and ultra‐large interlayer distance toward realizing fast‐charging capability in half and full cells.
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