•Meta-mafic rocks in the central Liaodong Peninsula was emplaced at 2154Ma, and metamorphosed at 1897Ma.•These rocks were derived from a depleted mantle source with extremely minimal crustal ...contamination.•These rocks formed in a back-arc basin.
The central Liaodong Peninsula is located in the northwestern part of the Jiao-Liao-Ji Belt in the Eastern Block of the North China Craton. Surface rocks in this region are voluminous meta-mafic rocks, which mainly comprise amphibolite and metamorphic gabbro or diabase. We present zircon cathodoluminescence images, U–Pb dates, and Lu–Hf isotope data, as well as whole-rock geochemical data for these rocks, in order to constrain the tectonic nature and evolution of the Jiao-Liao-Ji Belt. Zircons from these meta-mafic rocks can be divided into two groups, with one having a typical magmatic origin and the other a metamorphic origin. Zircon U–Pb dating and Lu–Hf isotopic results show that the magmatic zircons have two peak ages at 2503 and 2154Ma, with the former have ɛHf=+7.1 to +8.1 and single-stage model ages (THf)=2.50–2.55Ga, indicating that these captured or inherited zircons formed at ca. 2.50Ga by partial melting of coeval juvenile crust. The younger magmatic zircons have ɛHf=+3.2 to +9.6, mainly varying from +7.4 to +9.6 (average=+8.7), and THf=2.15–2.34Ga (peak at 2.19Ga), suggesting that the meta-mafic rocks were emplaced at ca. 2.15Ga and derived by partial melting of depleted mantle. The metamorphic zircons yield a peak age of 1897Ma and have ɛHf=−4.5 to +6.8. These zircons can be further divided into three groups on the basis of Hf isotope data (i.e., ɛHf=−4.5 to −2.3, −0.6 to +1.0, and +3.1 to +6.8; THf=2.39–2.54, 2.26–2.39, and 2.03–2.11Ga, respectively), indicating they were derived by reworking of Neoarchean–Paleoproterozoic ancient crust and some Paleoproterozoic juvenile crust. Thus there existed two crustal growth events at 2.50 and 2.15Ga and one reworking event at ca. 1.90Ga in the Eastern Block. Geochemical data show that these meta-mafic rocks are characterized by: SiO2=47.3–49.8wt.%; TiO2=0.97–1.59wt.%;K2O=0.39–1.95wt.%; Na2O/K2O=1.03–4.85; Mg#=39–52; Cr=29–247ppm; and Ni=24.4–73.4ppm. These features, combined with low total rare earth element concentrations (ΣREE), relative enrichment in light REE, significant positive Rb, Ba, K, and P anomalies, and depletions in high-field strength elements (e.g., Nb, Ta, and Ti), indicate derivation by partial melting of depleted lithospheric mantle that had been metasomatized by subduction-derived fluids, with little or no crustal contamination during magma ascent. Given our dating results and the regional geological framework, we propose that the subduction in the eastern Longgang Block took place at least in age of 2.15Ga, and that the meta-mafic rocks in the central Liaodong Peninsula may have formed in a back-arc basin. However, the tectonic location of this magmatic arc and its relationship with the Nangrim Block need to be further studied to confirm this hypothesis.
Anticipated more frequent extreme events due to changes in global climatic variability requires adaptation of crop species to multi-occurrence abiotic stresses hereby sustaining the food security. ...Priming, by pre-exposure of plants to an eliciting factor, enables plants to be more tolerant to later biotic or abiotic stress events. Priming induced “stress memory” exists in both present generation and the offspring. Thus, priming is suggested to be a promising strategy for plants to cope with the abiotic stresses under global change scenarios. In this review, the underlying physiological and molecular mechanisms of priming induced enhancement of stress tolerance to the major abiotic stresses of drought and waterlogging, and high and low temperature in crop plants were discussed, and the potential to utilize the priming effect for sustaining crop productivity in future climates was also suggested.
Wing polymorphism is an evolutionary feature found in a wide variety of insects, which offers a model system for studying the evolutionary significance of dispersal. In the wing-dimorphic planthopper ...Nilaparvata lugens, the insulin/insulin-like growth factor signaling (IIS) pathway acts as a 'master signal' that directs the development of either long-winged (LW) or short-winged (SW) morphs via regulation of the activity of Forkhead transcription factor subgroup O (NlFoxO). However, downstream effectors of the IIS-FoxO signaling cascade that mediate alternative wing morphs are unclear. Here we found that vestigial (Nlvg), a key wing-patterning gene, is selectively and temporally regulated by the IIS-FoxO signaling cascade during the wing-morph decision stage (fifth-instar stage). RNA interference (RNAi)-mediated silencing of Nlfoxo increase Nlvg expression in the fifth-instar stage (the last nymphal stage), thereby inducing LW development. Conversely, silencing of Nlvg can antagonize the effects of IIS activity on LW development, redirecting wing commitment from LW to the morph with intermediate wing size. In vitro and in vivo binding assays indicated that NlFoxO protein may suppress Nlvg expression by directly binding to the first intron region of the Nlvg locus. Our findings provide a first glimpse of the link connecting the IIS pathway to the wing-patterning network on the developmental plasticity of wings in insects, and help us understanding how phenotypic diversity is generated by the modification of a common set of pattern elements.
Cancer-associated fibroblasts (CAFs), the most abundant cells in the tumor microenvironment, have prominent roles in the development of solid tumors as stromal targets. However, the underlying ...mechanism of CAFs' function in oral squamous cell carcinoma (OSCC) development remains unclear. Here, we investigated the role of lysyl oxidase (LOX) expression in CAFs in tumor stromal remodeling and the mechanism of its effect on OSCC progression.
Multiple immunohistochemistry (IHC) staining was performed to detect the correlation of CAFs and LOX in the stroma of OSCC specimens, as well as the correlation with clinicopathological parameters and prognosis. The expression of LOX in CAFs were detected by RT-qPCR and western blot. The effects of LOX in CAFs on the biological characteristics of OSCC cell line were investigated using CCK-8, wound-healing and transwell assay. CAFs were co-cultured with type I collagen in vitro, and collagen contraction test, microstructure observation and rheometer were used to detect the effect of CAFs on remodeling collagen matrix. Then, collagen with different stiffness were established to investigate the effect of matrix stiffness on the progression of OSCC. Moreover, we used focal adhesion kinase (FAK) phosphorylation inhibitors to explored whether the increase in matrix stiffness promote the progression of OSCC through activating FAK phosphorylation pathway.
LOX was colocalized with CAFs in the stroma of OSCC tissues, and its expression was significantly related to the degree of malignant differentiation and poor prognosis in OSCC. LOX was highly expressed in CAFs, and its knockdown impaired the proliferation, migration, invasion and EMT process of OSCC cells. The expression of LOX in CAFs can catalyze collagen crosslinking and increase matrix stiffness. Furthermore, CAFs-derived LOX-mediated increase in collagen stiffness induced morphological changes and promoted invasion and EMT process in OSCC cells by activating FAK phosphorylation pathway.
Our findings suggest that CAFs highly express LOX in the stroma of OSCC and can remodel the matrix collagen microenvironment, and the increase in matrix stiffness mediated by CAFs-derived LOX promotes OSCC development through FAK phosphorylation pathway. Thus, LOX may be a potential target for the early diagnosis and therapeutic treatment of OSCC.
The intestinal flora is recognized as a significant contributor to the immune system. In this research, the protective effects of oyster peptides on immune regulation and intestinal microbiota were ...investigated in mice treated with cyclophosphamide. The results showed that oyster peptides restored the indexes of thymus, spleen and liver, stimulated cytokines secretion and promoted the relative mRNA levels of Th1/Th2 cytokines (IL-2, IFN-γ, IL-4 and IL-10). The mRNA levels of Occludin, Claudin-1, ZO-1, and Mucin-2 were up-regulated, and the NF-κB signaling pathway was also activated after oyster peptides administration. Furthermore, oyster peptides treatment reduced the proportion of
/
, increased the relative abundance of
,
,
and the content of short-chain fatty acids, and reversed the composition of intestinal microflora similar to that of normal mice. In conclusion, oyster peptides effectively ameliorated cyclophosphamide-induced intestinal damage and modified gut microbiota structure in mice, and might be utilized as a beneficial ingredient in functional foods for immune regulation.
Small‐molecule electrooxidation‐boosted water electrolysis (WE) is an energy‐saving method for hydrogen (H2) production. Herein, PdPt bimetallenes (PdPt BMLs) are obtained through the simple galvanic ...replacement reaction. PdPt BMLs reveal 2.93‐fold enhancement in intrinsic electroactivity and 4.53‐fold enhancement in mass electroactivity for the formate oxidation reaction (FOR) with respect to Pd metallenes (Pd MLs) at 0.50 V potential due to the synergistic effect. Meanwhile, the introduction of Pt atoms also considerably increases the electroactivity of PdPt BMLs for hydrogen evolution reaction (HER) with respect to Pd MLs in an alkaline medium, which even exceeds that with the use of commercial Pt nanocrystals. Inspired by the outstanding FOR and HER electroactivity of bifunctional PdPt BMLs, a two‐electrode FOR‐boosted WE system (FOR‐WE) is constructed by using PdPt BMLs as the cathode and the anode. The FOR‐WE system only requires an operational voltage of 0.31 V to achieve H2 production, which is 1.48 V lower than that (ca. 1.79 V) with the use of the traditional WE system.
PdPt bimetallenes (PdPt BMLs) are synthesized by a galvanic replacement reaction, which leads to enhancement of intrinsic electroactivity for both the formate oxidation reaction and the hydrogen evolution reaction with respect to Pd metallence due to the synergistic effect. Also, the PdPt BMLs||PdPt BMLs formate electrolyzer requires an operational voltage of only 0.31 V for H2 production, which is 1.48 V lower than that of the traditional water electrolysis system.
Despite the great agricultural and ecological importance of efficient use of urea-containing nitrogen fertilizers by crops, molecular and physiological identities of urea transport in higher plants ...have been investigated only in Arabidopsis.
We performed short-time urea-influx assays which have identified a low-affinity and high-affinity (K
m of 7.55 μM) transport system for urea-uptake by rice roots (Oryza sativa).
A high-affinity urea transporter OsDUR3 from rice was functionally characterized here for the first time among crops. OsDUR3 encodes an integral membrane-protein with 721 amino acid residues and 15 predicted transmembrane domains. Heterologous expression demonstrated that OsDUR3 restored yeast dur3-mutant growth on urea and facilitated urea import with a K
m of c. 10 μM in Xenopus oocytes.
Quantitative reverse-transcription polymerase chain reaction (qPCR) analysis revealed upregulation of OsDUR3 in rice roots under nitrogen-deficiency and urea-resupply after nitrogen-starvation. Importantly, overexpression of OsDUR3 complemented the Arabidopsis atdur3-1 mutant, improving growth on low urea and increasing root urea-uptake markedly. Together with its plasma membrane localization detected by green fluorescent protein (GFP)-tagging and with findings that disruption of OsDUR3 by T-DNA reduces rice growth on urea and urea uptake, we suggest that OsDUR3 is an active urea transporter that plays a significant role in effective urea acquisition and utilisation in rice.
Heat shock factor 1 (HSF1) is highly expressed in various malignancies and is a potential modulator of tumor progression. Emerging evidence suggests that HSF1 activation in stromal cells is closely ...related to poor patient prognosis. However, the role of HSF1 in oral squamous cell carcinoma (OSCC) remains elusive. We aimed to investigate the function of HSF1 in cancer‐associated fibroblasts (CAFs) of the tumor microenvironment (TME) and in tumor development. In the present study, we found that HSF1 was highly expressed in both CAFs and tumor cells, and was significantly correlated with poor prognosis and overall survival. Moreover, HSF1 overexpression in CAFs resulted in a fibroblast‐like phenotype of Cal27 cells, induced epithelial‐mesenchymal transition (EMT), and promoted proliferation, migration and invasion in Cal27 cells. HSF1 knockdown attenuated features of CAFs and reduced EMT, proliferation, migration and invasion in Cal27 cells. Furthermore, HSF1 in CAFs promoted tumor growth in nude mice. Taken together, these data suggest that HSF1 expression in CAFs drive OSCC progression, and could serve as an independent prognostic marker of patients with OSCC. Thus, HSF1 is a potent mediator of OSCC malignancy.
Infiltration of α‐SMA‐positive CAFs could promote OSCC progression. Furthermore, the expression of HSF1 in both CAFs and tumor cells was positively associated with poor prognosis and OS. Moreover, HSF1 expression in CAFs induced tumor cells to undergo partial EMT and enhanced the migration and invasion of cancer cells, and knockdown of HSF1 in CAFs reduced tumor growth.
Photoexcitation of spin crossover (SCO) complexes can trigger extensive electronic spin transitions and transformation of molecular structure. However, the precise nature of the associated ultrafast ...structural dynamics remains elusive, especially in the solid state. Here, we studied a single‐crystal SCO material with femtosecond electron diffraction (FED). The unique capability of FED allows us to directly probe atomic motions and to track ultrafast structural changes within a crystal lattice. By monitoring the time‐dependent changes of the Bragg reflections, we observed the formation of a photoinduced structure similar to the thermally induced high‐spin state. The data and refinement calculations indicate the global structural reorganization within 2.3 ps, as the metal–ligand bond distribution narrows during intramolecular vibrational energy redistribution (IVR) driving the intermolecular rearrangement. Three independent dynamical group are identified to model the structural dynamics upon photoinduced SCO.
Ultrafast: Femtosecond electron diffraction has been used to directly study the structural dynamics in the spin crossover compound Fe(PM‐AzA)2(NCS)2. Three dynamic modes, which all occur with a time constant of 2.3 ps are found: metal–ligand bond elongation, ligand motion, and local unit cell expansion, driven by the narrowing of the metal–ligand bond distribution during the vibrational cooling process.
L‐Methionine is the unique sulfur‐containing amino acid essential for humans and animals, which is widely used in pharmaceutical, food and feed industries. Its green and efficient production has ...attracted a great deal of attention. Fermentation‐enzymatic coupling route is regarded to be promising for L‐methionine biosynthesis, while O‐succinyl‐L‐homoserine mercaptotransferase (MetZ) is the key biocatalyst. Exploring and engineering of MetZ with ideal catalytic properties is highly desired. Herein, the MetZ from Chromobacterium violaceum (CvMetZ) was screened and through in silico analyses, potential beneficial amino acid residues both at the access channel and around the oxygen anion holes were anchored for site‐saturation mutagenesis. The positive mutants were obtained with improved activity for L‐methionine biosynthesis using O‐succinyl‐L‐homoserine (OSH) and methyl mercaptan as substrate. The best mutant was further applied for L‐methionine production and supply of methyl mercaptan was optimized in a fed‐batch approach. The conversion of 100 g/L OSH reached 92% with L‐methionine yield of 62.6 g/L, which was well coupled with the OSH fermentation level.
PDF
