•Surface treatment enhanced the hydrothermal durability of fibre/epoxy interface.•Moisture absorption and desorption tests were carried out for CFRP plates.•Dynamic mechanical thermal analysis ...provides insight for degradation of interface.•Damping at interface (tan δin) was linked with the interlaminar shear strength (ILSS).
This paper presents an investigation on the effects of hydrothermal aging on carbon fibre reinforced polymer (CFRP) composites with different interfacial bonding strength. The combination of electrochemical oxidation and sizing treatments effectively enhanced the long-term interlaminar shear strength (ILSS) retention from 0.24–0.38 to 0.74–0.86 for CFRP in hydrothermal environment, which basically met the specified environmental reduction factor CE (0.85) given in ACI 440.2R-08. The improved durability of fibre/epoxy interface was also evidenced by the moisture absorption and desorption tests and scanning electron microscopy (SEM). In addition, the dynamic mechanical thermal analysis (DMTA) was directly used to characterize the degradation of interface adhesion for CFRP, and the damping at fibre/epoxy interface (tan δin) was evaluated and finally linked with the ILSS results.
A simple, new type of chiral sulfinamide monophosphines, the so‐called Ming‐Phos ligands, is reported; these ligands could be easily prepared from inexpensive and commercially available starting ...materials. The Ming‐Phos ligands performed well in the enantioselective gold‐catalyzed cycloaddition reaction of 2‐(1‐alkynyl)‐alk‐2‐en‐1‐ones with nitrones. Both enantiomers of the products could be obtained in good yields and with excellent diastereo‐ and enantioselectivity through transformations that were catalyzed by gold complexes derived from two diastereomers of Ming‐Phos ligand M5 (Ar=1‐naphthyl).
Ming‐Phos: A new type of simple chiral sulfinamide monophosphine ligands, the so‐called Ming‐Phos ligands, can be easily prepared from inexpensive and commercially available starting materials. The enantioselectivity of the reaction of yne–enones 1 with nitrones could be controlled by the diastereomeric ligands (R,RS)‐M5 and (S,RS)‐M5.
Holometabolous insects stop feeding at the final larval instar stage and then undergo metamorphosis; however, the mechanism is unclear. In the present study, using the serious lepidopteran ...agricultural pest Helicoverpa armigera as a model, we revealed that 20-hydroxyecdysone (20E) binds to the dopamine receptor (DopEcR), a G protein-coupled receptor, to stop larval feeding and promote pupation. DopEcR was expressed in various tissues and its level increased during metamorphic molting under 20E regulation. The 20E titer was low during larval feeding stages and high during wandering stages. By contrast, the dopamine (DA) titer was high during larval feeding stages and low during the wandering stages. Injection of 20E or blocking dopamine receptors using the inhibitor flupentixol decreased larval food consumption and body weight. Knockdown of DopEcR repressed larval feeding, growth, and pupation. 20E, via DopEcR, promoted apoptosis; and DA, via DopEcR, induced cell proliferation. 20E opposed DA function by repressing DA-induced cell proliferation and AKT phosphorylation. 20E, via DopEcR, induced gene expression and a rapid increase in intracellular calcium ions and cAMP. 20E induced the interaction of DopEcR with G proteins αs and αq. 20E, via DopEcR, induced protein phosphorylation and binding of the EcRB1-USP1 transcription complex to the ecdysone response element. DopEcR could bind 20E inside the cell membrane or after being isolated from the cell membrane. Mutation of DopEcR decreased 20E binding levels and related cellular responses. 20E competed with DA to bind to DopEcR. The results of the present study suggested that 20E, via binding to DopEcR, arrests larval feeding and promotes pupation.
Nano-scale zero-valent iron (nZVI) is one of the most intensively studied materials for environmental cleanup uses over the past 20 years or so. Freshly prepared nZVI is highly reactive due to its ...high specific surface area and strong reducing power. Over years, the classic borohydride reduction method for preparing nZVI has been modified by use of various stabilizers or surface modifiers to acquire more stable and soil deliverable nZVI for treatment of different organic and inorganic contaminants in water and soil. While most studies have been focused on testing nZVI for water treatment, the greater potential or advantage of nZVI appears to be for in situ remediation of contaminated soil and groundwater by directly delivering stabilized nZVI into the contaminated subsurface as it was proposed from the beginning. Compared to conventional remediation practices, the in situ remediation technique using stabilized nZVI offers some unique advantages. This work provides an update on the latest development of stabilized nZVI for various environmental cleanup uses, and overviews the evolution and environmental applications of stabilized nZVI. Commonly used stabilizers are compared and the stabilizing mechanisms are discussed. The effectiveness and constraints of the nZVI-based in situ remediation technology are summarized. This review also reveals some critical knowledge gaps and research needs, such as interactions between delivered nZVI and the local biogeochemical conditions.
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•Critically reviewed applications of stabilized ZVI nanoparticles in last 20 years.•Compared effectiveness of various stabilizers and elucidated stabilizing mechanism.•Identified critical knowledge gaps and constraints of ZVI-based cleanup technology.•Stabilizers enhance soil deliverability and reactivity of nZVI for in situ remediation.•Stabilized ZVI nanoparticles do not pose significant adverse effects on biota.
Background
Oxidative stress-induced endothelial dysfunction and pyroptosis play an important role during chronic kidney disease (CKD) progression. Neferine, which is an alkaloid ingredient from the ...lotus seed embryo, has many biological actions such as anti-inflammatory, anticancer and antioxidant. However, the role of neferine in endothelial cell pyroptosis and the involved mechanism remain obscure. The aim is to probe the protective effects of neferine on cell pyroptosis and the involved underlying mechanism.
Methods
After the HUVECs were primed with neferine treatment for 2 h prior to LPS and ATP exposure for 24 h, the cell proliferation was determined by BrdU; the cell LDH release was detected by LDH kits; the levels of intracellular ROS, MDA and SOD were tested by detection kits; Caspase-1 activity kit was used to determine caspase-1 activity; the contents of NLRP3, ASC, caspase-1, IL-1β, IL-18 and GSDMD were tested by RT-PCR and western blot.
Results
We found that neferine could inhibit LPS-ATP-induced oxidative stress and the activation of NLRP3 inflammasome signaling, and increased the endothelial cell viability and SOD production. siRNA which mediated the knockdown of NLRP3 promoted the neferine-induced inhibition effects of cell pyroptosis. Furthermore, these neferine-induced effects were reversed by the over-expression of NLRP3.
Conclusions
Our findings indicated neferine may reduce ROS by anti-oxidation and inhibit LPS-ATP-induced endothelial cell pyroptosis via blocking ROS/NLRP3/Caspase-1 signaling pathway, which provides the evidence for therapeutic effect in CKD.
Great enthusiasm in single-atom catalysts (SACs) for the oxygen reduction reaction (ORR) has been aroused by the discovery of M–NX as a promising ORR catalysis center. However, the performance of ...SACs lags far behind that of state-of-the-art Pt due to the unsatisfactory adsorption–desorption behaviors of the reported catalytic centers. To address this issue, rational manipulation of the active site configuration toward a well-managed energy level and geometric structure is urgently desired, yet still remains a challenge. Herein, we report a novel strategy to accomplish this task through the construction of an Fe–Co dual-atom centered site. A spontaneously absorbed electron-withdrawing OH ligand was proposed to act proactively as an energy level modifier to empower easy intermediate desorption, while the triangular Fe–Co–OH coordination facilitates O–O bond scission. Benefiting from these attributes, the as-constructed FeCoN5–OH site enables an ORR onset potential and half-wave potential of up to 1.02 and 0.86 V (vs RHE), respectively, with an intrinsic activity over 20 times higher than the single-atom FeN4 site. Our finding not only opens up a novel strategy to tailor the electronic structure of an atomic site toward boosted activity but also provides new insights into the fundamental understanding of diatomic sites for ORR electrocatalysis.
Salt stress can significantly affect plant growth and agricultural productivity. Receptor-like kinases (RLKs) are believed to play essential roles in plant growth, development, and responses to ...abiotic stresses. Here, we identify a receptor-like cytoplasmic kinase, salt tolerance receptor-like cytoplasmic kinase 1 (STRK1), from rice (Oryza sativa) that positively regulates salt and oxidative stress tolerance. Our results show that STRK1 anchors and interacts with CatC at the plasma membrane via palmitoylation. CatC is phosphorylated mainly at Tyr-210 and is activated by STRK1. The phosphorylation mimic form CatCY210D exhibits higher catalase activity both in vitro and in planta, and salt stress enhances STRK1-mediated tyrosine phosphorylation on CatC. Compared with wild-type plants, STRK1-overexpressing plants exhibited higher catalase activity and lower accumulation of H2O2 as well as higher tolerance to salt and oxidative stress. Our findings demonstrate that STRK1 improves salt and oxidative tolerance by phosphorylating and activating CatC and thereby regulating H2O2 homeostasis. Moreover, overexpression of STRK1 in rice not only improved growth at the seedling stage but also markedly limited the grain yield loss under salt stress conditions. Together, these results offer an opportunity to improve rice grain yield under salt stress.
All in a sequence: An organocatalyzed Morita–Baylis–Hillman (MBH)/bromination/3+2 annulation sequence for highly stereoselective syntheses of bis(spirooxindole)s featuring adjacent ...spiro‐stereocenters is described. The key step is an unprecedented catalytic asymmetric 3+2 annulation of isatin‐derived MBH adducts, containing a tetrasubstituted alkene moiety, with isatins.
•AMSTAR and PRISMA assessments were conducted for the included studies, to better guide clinical care of pregnant women and inform future research.•Risk, protective, and controversial factors for ...postpartum depression were identified.•The relevant mechanisms of action and the biological bases were discussed for each risk factor.
Postpartum depression (PPD) is the most common psychiatric condition after childbirth which not only effects the mother’s health, but also might have impact on child’s development and parenting behaviors. Because the etiology of PPD has not been fully cleared, the efforts towards identification of risk factors are crucial for both the children and mother’s health.
PubMed, EMBASE and PsycINFO databases were searched since inception until July 2019 to collect data about the risk factors of PPD and only systematic review and meta-analysis can be included.
To identify the real risk factors, protective factors and controversial factors, nineteen parts of the interpretation were adopted. The risk factors are mainly concentrated in the following aspects: violence and abuse, immigration status, gestational diabetes, cesarean section, depressive history, vitamin D deficiency, obese and overweight, postpartum sleep disruption and poor postpartum sleep, lack of social support, traditional dietary pattern (Japanese, Indian, United Kingdom, and Brazilian dietary pattern), multiple births, preterm and low-birth-weight infants, postpartum anemia, negative birth experience. The controversial factors are serum level of cortisol, thyroid peroxidase autoantibodies status, acculturation, traditional confinement practices. Skin-to-skin care, higher concentrations of DHA in mothers’ milk, greater seafood consumption, healthy dietary patterns, multivitamin supplementation, fish and PUFA intake, calcium, Vitamin D, zinc and possibly selenium are protective factors.
Thirteen risk factors were identified, but five factors still controversial due to the insufficient of the evidence. What’s more, skin-to-skin care and some nutrition related factors are protective factors against PPD.
In this paper, we propose a time-periodic reaction–diffusion model which incorporates seasonality, spatial heterogeneity and the extrinsic incubation period (EIP) of the parasite. The basic ...reproduction number
R
0
is derived, and it is shown that the disease-free periodic solution is globally attractive if
R
0
<
1
, while there is an endemic periodic solution and the disease is uniformly persistent if
R
0
>
1
. Numerical simulations indicate that prolonging the EIP may be helpful in the disease control, while spatial heterogeneity of the disease transmission coefficient may increase the disease burden.
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