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Previous simulations of different-sized MTO fluidized beds indicated that the reactive predictions gradually deviate from the experiment with the reactor scale-up. This study aimed to find the underlying reasons by investigating effects of kinetic models and coke content. Two kinetic models were separately integrated into the multi-fluid model, and a reactor model was then established considering coke distribution. It showed that the ratio of ethylene to propylene is still over-predicted even the kinetic model considers the conversion of ethylene to propylene if using average coke content in simulation, but considering a reasonable coke content distribution both models can give better predictions in methanol conversion, hydrocarbon products and selectivity to light olefins. It indicated that coke content distribution plays a critical role in reaction predictions and the kinetic models with similar component classification mainly affect the variation of products along the bed height due to different reaction routes.

Methanol-to-olefins (MTO) is industrially applied to produce ethylene and propylene using methanol converted from coal, synthetic gas, and biomass. SAPO-34 zeolites, as the most efficient catalyst in MTO process, are subject to the rapid deactivation due to coke deposition. Recent work shows that steam regeneration can provide advantages such as low carbon dioxide emission and enhanced light olefins yield in MTO process, compared to that by air regeneration. A kinetic study on the steam regeneration of spent SAPO-34 catalyst has been carried out in this work. In doing so, we first investigated the effect of temperature on the regeneration performance by monitoring the crystal structure, acidity, residual coke properties and other structural parameters. The results show that with the increase of regeneration temperature, the compositions of residual coke on the catalyst change from pyrene and phenanthrene to naphthalene, which are normally considered as active hydrocarbon pool species in MTO reaction. However, when the regeneration temperature is too high, nitrogen oxides can be found in the residual coke. Meanwhile, as the regeneration temperature increases, the quantity of residual coke reduces and the acidity, BET surface area and pore structure of the regenerated samples can be better recovered, resulting in prolonging catalyst lifetime. We have further derived the kinetics of steam regeneration, and obtained an activation energy of about 177.8 kJ·mol−1. Compared that with air regeneration, the activation energy of steam regeneration is higher, indicating that the steam regeneration process is more difficult to occur.

Summary The limitation of commercial single-crystal substrates and the lack of continuous strain tunability preclude the ability to take full advantage of strain engineering for further exploring novel properties and exhaustively studying fundamental physics in complex oxides. Here, we report an approach for imposing continuously tunable epitaxial strain in oxide heterostructures beyond substrate limitations by inserting an interface layer through tailoring of its gradual strain relaxation. Taking BiFeO3 as a model system, we demonstrate the introduction of an ultrathin interface layer that allows the creation of desired strain states that can induce phase transition and stabilize a super-tetragonal phase as well as morphotropic phase boundaries, overcoming substrate limitations. Continuously tunable strain from tension to compression can be generated by precisely adjusting the interface layer thickness, enabling the achievement of continuous orthorhombic–rhombohedral-like–tetragonal-like phase transition. This proposed route could be extended to other oxide heterostructures, providing a platform for creating exotic phases and emergent phenomena.

Methanol-to-olefins (MTO), the most important catalytic process producing ethylene and propylene from non-oil feedstocks (coal, natural gas, biomass, CO2, etc.), is hindered by rapid catalyst deactivation due to coke deposition. Common practice to recover catalyst activity, i.e. removing coke via air combustion or steam gasification, unavoidably eliminates the active hydrocarbon pool species (HCPs) favoring light olefins formation. Density functional theory calculations and structured illumination microscopy reveal that naphthalenic cations, active HCPs enhancing ethylene production, are highly stable within SAPO-34 zeolites at high temperature. Here, we demonstrate a strategy of directly transforming coke to naphthalenic species in SAPO-34 zeolites via steam cracking. Fluidized bed reactor-regenerator pilot experiments show that an unexpectedly high light olefins selectivity of 85% is achieved in MTO reaction with 88% valuable CO and H2 and negligible CO2 as byproducts from regeneration under industrial-alike continuous operations. This strategy significantly boosts the economics and sustainability of MTO process., Methanol-to-olefins is hindered by rapid catalyst deactivation due to coke deposition. Here the authors demonstrate an approach of directly transforming coke to active intermediates to simultaneously recover catalyst activity and boost light olefins selectivity.

Silicate micro- and nano-additives are multifunctional in relation to cement systems. Their application can solve a wide range of technological problems while maintaining the economic efficiency of technical solutions. The effect of silicate additives and fillers is determined by their level of dispersion, due to which the technologies for producing nano- and submicro-sized dispersed materials are being developed. The combination of mechanochemical synthesis of modified calcium hydrosilicates with subsequent thermolysis makes it possible to produce calcium silicate dispersions (SCD), which differ in polymodality of the fractional composition including submicro (10–7–10–6 m) and microdimensional (≥10–6 m) modes. The main element of the technology is the use of modifying carbohydrate, which acts as a stabilizer of hydrated phases of silicates. A comparative study of SCD produced using sucrose (sSCD) and lactose (lSCD) revealed the effect of these carbohydrates on the properties of sSCD and lSCD, as well as their effectiveness as a component of cementitious composite binder. It was found that the level of adsorption of modifying carbohydrate determines the physical properties of SCD (granulometry, specific surface area). The relatively high residual content of free sucrose (0.24%) in the composition of sSCD prevents the consolidation of silicates nanoparticles formed during the thermolysis, causes a high content of submicro sized fractions and a high specific surface area with sSCD (26.3 ± 0.7 m2/g). Lactose is absorbed by the silicate phase; the residual content of free lactose does not exceed 0.028% of lSCD. The low content of stabilizing carbohydrate contributes to the development of nanoparticle consolidation, a decrease in the specific surface area of lSCD to 13.0 ± 0.2 m2/g and content of submicrosized fractions. The residual content of free carbohydrates and particle size characteristics of sSCD and lSCD determine the nature of their influence on Cement-SCD-based concrete setting and hardening. The presence of residual sucrose in the composition of sSCD and fine fractions determines the competitive nature of the processes of retardation of hardening and acceleration of hardening of the cement system due to the nucleation effect, as a result of which the curve of the setting time is extreme. In addition, the inhibitory effect of sucrose reduces the strength of concrete on the 7th day. By the 28th day, the inhibitory effect of sucrose has been overcome, and concrete samples demonstrate an 18% increase in compressive strength with a sSCD content of 30%. The low content of residual free lactose in the composition of lSCD causes the nucleation effect. As a result, there is a monotonous reduction in the setting time of concrete mix with an increase in the content of lSCD in the composition of HF, as well as a significant increase in concrete strength (up to 127%) on the 7th day. At the same time, on the 28th day the strength of concrete increases slightly

Ubiquitin‐specific protease 11 (USP11) has been implicated in the regulation of DNA repair, apoptosis, signal transduction and cell cycle. It belongs to a USP subfamily of deubiquitinases. Although previous research has shown that USP11 overexpression is frequently found in melanoma and is correlated with a poor prognosis, the potential molecular mechanism of USP11 in melanoma remains indefinitive. Here, we report that USP11 and NONO colocalize and interact with each other in the nucleus of melanoma cells. As a result, the knockdown of USP11 decreases NONO levels. Whereas, overexpression of USP11 increases NONO levels in a dose‐dependent manner. Furthermore, we reveal that USP11 protects NONO protein from proteasome‐mediated degradation by removing poly‐ubiquitin chains conjugated onto NONO. Functionally, USP11 mediated melanoma cell proliferation via the regulation of NONO levels because ablation of USP11 inhibits the proliferation which could be rescued by ectopic expression of NONO protein. Moreover, a significant positive correlation between USP11 and NONO concentrations was found in clinical melanoma samples. Collectively, these results demonstrate that USP11 is a new deubiquitinase of NONO and that the signalling axis of USP11‐NONO is significantly involved in melanoma proliferation.

In industrial catalytic processes, coke deposition can cause catalyst deactivation by covering acid sites and/or blocking pores. The regeneration of deactivated catalysts, thereby removing the coke and simultaneously restoring the catalytic activity, is highly desired. Despite various chemical reactions and methods are available to remove coke, developing reliable, efficient, and economic regeneration methods for catalytic processes still remains a challenge in industrial practice. In this paper, the current progress of regeneration methods such as oxidation (air, ozone and oxynitride), gasification (carbon dioxide and water steam), and hydrogenation (hydrogen) is reviewed, which hopefully can shed some light on the design and optimization of catalysts and the related processes.

The regeneration kinetics of coke on an industrial methanol-to-olefin (MTO) catalyst was studied via thermogravimetric analysis under the air atmosphere. To minimize the uncertainty of the kinetic parameters, four model-free methods were employed to calculate the regeneration activation energy. It was found that the activation energies obtained by all methods are quite consistent for any given coke conversion. An average activation energy of 141.1 kJ/mol was obtained for combustion of coke on the industrial MTO catalyst. The master-plot method was then employed to decide the regeneration model function. It showed that the combustion process of coke on the industrial MTO catalyst may be depicted using the Fn model. A comparison between the model prediction and additional experimental results demonstrated that the regeneration kinetics model built in this work can work very well under operation conditions of industrial interest and favor the optimization and design of a regenerator in an industrial MTO unit.

This study aimed to provide systematic evidence for the association between multiorgan dysfunction and COVID-19 development. Several online databases were searched for articles published until May 13, 2020. Two investigators independently selected trials, extracted data, and evaluated the quality of individual trials. Single-arm meta-analysis was performed to summarize the clinical features of confirmed COVID-19 patients. Fixed effects meta-analysis was performed for clinically relevant parameters that were closely related to the patients' various organ functions. A total of 73 studies, including 171,108 patients, were included in this analysis. The overall incidence of severe COVID-19 and mortality were 24% (95% confidence interval [CI], 20%-28%) and 2% (95% CI, 1%-3%), respectively. Patients with hypertension (odds ratio [OR] = 2.40; 95% CI, 2.08-2.78), cardiovascular disease (CVD) (OR = 3.54; 95% CI, 2.68-4.68), chronic obstructive pulmonary disease (COPD) (OR=3.70; 95% CI, 2.93-4.68), chronic liver disease (CLD) (OR=1.48; 95% CI, 1.09-2.01), chronic kidney disease (CKD) (OR = 1.84; 95% CI, 1.47-2.30), chronic cerebrovascular diseases (OR = 2.53; 95% CI, 1.84-3.49) and chronic gastrointestinal (GI) disease (OR = 2.13; 95% CI, 1.12-4.05) were more likely to develop severe COVID-19. Increased levels of lactate dehydrogenase (LDH), creatine kinase (CK), high-sensitivity cardiac troponin I (hs-cTnI), myoglobin, creatinine, urea, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin were highly associated with severe COVID-19. The incidence of acute organ injuries, including acute cardiac injury (ACI); (OR = 11.87; 95% CI, 7.64-18.46), acute kidney injury (AKI); (OR=10.25; 95% CI, 7.60-13.84), acute respiratory distress syndrome (ARDS); (OR=27.66; 95% CI, 18.58-41.18), and acute cerebrovascular diseases (OR=9.22; 95% CI, 1.61-52.72) was more common in patients with severe COVID-19 than in patients with non-severe COVID-19. Patients with a history of organ dysfunction are more susceptible to severe conditions. COVID-19 can aggravate an acute multiorgan injury.

Multiple myeloma stem-like cells (MMSCs) are responsible for initiation and relapse, though novel treatment paradigms that effectively eradicate MMSCs are yet to be developed. Selective inhibition of the cell cycle regulatory kinase Wee1 by MK1775 is being explored as a potential anti-cancer therapeutic. We report that higher expression of Wee1 is correlated with poor survival in multiple myeloma (MM). The MM models and patient-derived CD138+ plasma cells are particularly sensitive to the growth-inhibitory effects of the Wee1 inhibitor MK1775. MK1775 induces Mus81-Eme1 endonuclease-mediated DNA damage in S-phase cell cycle that results in a blockade of replication and then apoptosis. Furthermore, MK1775 strongly suppresses the features of stemness in vitro, in vivo and in primary CD138+ cells by decreasing ALDH1+ cell fraction and the expression of ALDH1. In addition, co-treatment of MK1775 with bortezomib is synergistic in vitro and in vivo. Bortezomib, although it enhances ALDH1+ cells, when combined with MK1775 abrogates this stimulatory effect on stemness. Considering MM as an invariably incurable malignancy due to the presence of heterogenic myeloma stem-like cells, our study presents inhibition of Wee1 as a promising targeted therapy for MM and provides a compelling rationale to further investigate the activity of MK1775 against myeloma in clinical settings.

Calcium (Ca) is an essential macronutrient for plant growth. It can confer plants with resistance to abiotic stresses. However, little is understood about its role on biotic stresses. Frankliniella occidentalis (Thysanoptera: Thripidae) is one of the world’s most important invasive pests and poses a great threat to crops; meanwhile, it is hard to control due to its polyphagia and rapid reproduction. In order to clarify the effects of Ca on the induced defense of kidney bean plants against F. occidentalis by different application methods, we treated plants with different concentrations of CaCl2 solution using three methods, including spraying on leaf, root-irrigation, and seed soaking. The activities of defensive enzymes in leaves of kidney bean plants in response to F. occidentalis feeding as well as the developmental time of F. occidentalis were examined. The results showed that all the three treatment methods with different concentrations of CaCl2 solution could obviously induce activities of lipoxygenase (LOX), phenylalanine ammonia lyase (PAL), and β-1, 3-glucanase in leaves of kidney bean plants against F. occidentalis, while inductive effects of spraying the 10 mM CaCl2 on leaves were the best among all the treatments. Furthermore, we found that the developmental time of the whole immature stage of F. occidentalis feeding on plants sprayed with 10 mM CaCl2 was longer than those on control plants. Overall, our results indicated that the exogenous CaCl2 could enhance enzymatic activities in plants by thrips-induced effects, and spraying 10 mM CaCl2 on leaves of kidney bean plants showed the highest resistance against F. occidentalis.

Conversion of methanol to olefins (MTO) is an important non-oil alternative route for ethylene and propylene production, which has been industrialized based on a fluidized-bed process with a small-...

Protonated 3d transition-metal oxides often display low electronic conduction, which hampers their application in electric, magnetic, thermoelectric, and catalytic fields. Electronic conduction can be enhanced by co-inserting oxygen acceptors simultaneously. However, the currently used redox approaches hinder protons and oxygen ions co-insertion due to the selective switching issues. Here, a thermal hydration strategy for systematically exploring the synthesis of conductive protonated oxides from 3d transition-metal oxides is introduced. This strategy is illustrated by synthesizing a novel layered-oxide SrCoO3H from the brownmillerite SrCoO2.5. Compared to the insulating SrCoO2.5, SrCoO3H exhibits an unprecedented high electronic conductivity above room temperature, water uptake at 250 °C, and a thermoelectric power factor of up to 1.2 mW K-2 m-1 at 300 K. These findings open up opportunities for creating high-conductive protonated layered oxides by protons and oxygen ions co-doping. CC acknowledges support from the Spanish Ministry of Science, Innovation, and Universities under the “Ramón y Cajal” fellowship RYC2018-024947-I.

Sodium metal batteries are considered one of the most promising low-cost high-energy-density electrochemical energy storage systems. However, the growth of unfavourable Na metal deposition and the limited cell cycle life hamper the application of this battery system at a large scale. Here, we propose the use of polypropylene separator coated with a composite material comprising polydopamine and multilayer graphene to tackle these issues. The oxygen- and nitrogen- containing moieties as well as the nano- and meso- porous network of the coating allow cycling of Na metal electrodes in symmetric cell configuration for over 2000 h with a stable 4 mV overpotential at 1 mA cm−2. When tested in full Na || Na3V2(PO4)3 coin cell, the coated separator enables the delivery of a stable capacity of about 100 mAh g−1 for 500 cycles (90% capacity retention) at a specific current of 235 mA g−1 and satisfactory rate capability performances (i.e., 75 mAh g−1 at 3.5 A g−1)., The development of future Na metal batteries relies on the cycling stability of the metallic anode. Here, the authors propose a polypropylene separator functionalized with polydopamine and multilayer graphene to enable stable and prolonged Na metal cell cycling.

PROteolysis TArgeting Chimeras (PROTACs) induce targeted protein degradation by hijacking the intracellular ubiquitin proteasome system, thus emerging as a new strategy for drug development. However, most PROTACs generated lack cell-type selectivity and have poorly soluble in water. To address this drawback, we developed a novel PROTAC ZL216 using aptamer AS1411 as a targeting ligand of nucleolin to conjugate with a small molecule ligand of E3 ligase VHL, which shows high aqueous solubility and serum stability. Based on the differential expression of nucleolin on the cell surface, ZL216 could bind to and internalize into breast cancer cells, but not normal breast cells. Furthermore, we revealed that ZL216 promoted the formation of a nucleolin-ZL216-VHL ternary complex in breast cancer cells and potently induced nucleolin degradation in vitro and in vivo. As a result, ZL216 inhibited the proliferation and migration of breast cancer cells. These studies demonstrate that in addition to peptides and small molecule compounds, nuclei acid aptamers can also be used to generate PROTACs, which broadens the toolbox constructing PROTACs and provides a promising strategy for development of tumor-selective PROTACs.

As a commercial MTO catalyst, SAPO-34 zeolite exhibits excellent recyclability probably due to its intrinsic good hydrothermal stability. However, the structural dynamic changes of SAPO-34 catalyst induced by hydrocarbon pool (HP) species and the water formed during the MTO conversion as well as its long-term stability after continuous regenerations are rarely investigated and poorly understood. Herein, the dynamic changes of SAPO-34 framework during the MTO conversion were identified by 1D 27Al, 31P MAS NMR, and 2D 31P-27Al HETCOR NMR spectroscopy. The breakage of T-O-T bonds in SAPO-34 catalyst during long-term continuous regenerations in the MTO conversion could be efficiently suppressed by pre-coking. The combination of catalyst pre-coking and water co-feeding is established to be an efficient strategy to promote the catalytic efficiency and long-term stability of SAPO-34 catalysts in the commercial MTO processes, also sheds light on the development of other high stable zeolite catalyst in the commercial catalysis., Stability of zeolite catalysts is a highly desirable property for commercial methanol to olefins conversion but extremely challenging to achieve. Here, the authors combine the catalyst pre-coking and water co-feeding to develop an efficient strategy to enhance the long-term stability of SAPO-34 catalyst.

Melanoma is a highly aggressive tumor with a poor prognosis, and half of all melanoma patients harbor BRAF mutations. A BRAF inhibitor, vemurafenib (PLX4032), has been approved by the US Food and Drug Administration (FDA) and European Medicines Agency (EMA) to treat advanced melanoma patients with BRAFV600E mutation. However, the efficacy of vemurafenib is impeded by adaptive resistance in almost all patients. In this study, using a cell-based SELEX (systematic evolution of ligands by exponential enrichment) strategy, we obtained a DNA aptamer (named LL4) with high affinity and specificity against vemurafenib-resistant melanoma cells. Optimized truncated form (LL4A) specifically binds to vemurafenib-resistant melanoma cells with dissociation constants in the nanomolar range and with excellent stability and low toxicity. Meanwhile, fluorescence imaging confirmed that LL4A significantly accumulated in tumors formed by vemurafenib-resistant melanoma cells, but not in control tumors formed by their corresponding parental cells in vivo. Further, a transmembrane protein CD63 was identified as the binding target of aptamer LL4A using a pull-down assay combined with the liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. CD63 formed a supramolecular complex with TIMP1 and β1-integrin, activated the nuclear factor кB (NF-кB) and mitogen-activated protein kinase (MAPK) signaling pathways, and contributed to vemurafenib resistance. Potentially, the aptamer LL4A may be used diagnostically and therapeutically in humans to treat targeted vemurafenib-resistant melanoma. Keywords: melanoma, vemurafenib-resistant, aptamer, LL4A, CD63

The chars in the natural environment can affect the migration of polybrominated diphenyl ethers (PBDEs). However, there is insufficient research relating to the adsorption behavior and mechanisms of PBDEs on biochars. This study examined the adsorption kinetics of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) on maize straw-derived biochars (MSBCs) pyrolyzed at four different temperatures via batch experiments. The biochar samples were characterized using Fourier transform infrared (FTIR) spectroscopy, Raman spectra, and elemental analysis. A two-compartment first-order model and pseudo-second-order model exhibited a better fit compared to a pseudo-first-order model in describing the BDE-47 adsorption on biochars, which was dominated by a slow adsorption compartment and chemisorption. The MSBC pyrolyzed at 600 °C had the highest BDE-47 adsorption capacity owing to its relatively large specific surface area and relatively high aromaticity compared with the other three MSBCs pyrolyzed at 300, 400, and 500 °C. However, there was no significant difference in adsorption capacity among the other three biochars. The organic functional groups coupled with the graphene structures of biochars and the hydrophobic effect of the functional groups promoted the adsorption of BDE-47. Pore diffusion was not the sole rate-limiting step; film diffusion was also involved in the adsorption process of BDE-47 on biochars. The overall results demonstrate the transport and potential treatment of PBDEs using biochars.

Diabetic cardiomyopathy (DCM) is one of the major heart complications of diabetic patients. Hydrogen sulfide (H2S) is now recognized as an important signaling molecule and has been shown to attenuate the development of diabetic cardiomyopathy. However, the underlying mechanisms linking H2S and the development of DCM have not been fully elucidated. In the present study, we therefore sought to explore the role and mechanism of H2S in the pathogenesis of DCM by establishing high glucose-induced injury model in neonatal rat cardiomyocytes (NRCMs) and H9c2 cells. Using cystathionine gamma-lyase (CSE) overexpression and CSE interference vectors transfection, the cell viability, cell apoptosis. and oxidative stress were determined and compared between the treatment of high glucose induction and exgenous NaHS administration. Meanwhile, the relationship between the CSE/H2S system and Wnt/beta-catenin pathway was analyzed and discussed in the high glucose-induced cardiomyocytes. Our results indicated that H2S played an important protective role in high glucose-induced apoptosis and oxidative stress in cardiomyocytes, as shown by the decreased reactive oxygen species and malondialdehyde levels, and the increased activities of superoxide dismutase, catalase and glutathione peroxidase. Moreover, H2S could attenuate the Wnt/β-catenin signalling pathway and up-regulate the expression of haem oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO1) in the diabetic myocardium cells. Together, these results demonstrated that H2S could attenuate high glucose-induced myocardial injury in rat cardiomyocytes by suppressing Wnt/β-catenin pathway.

Determination of the amino acid phenylalanine is important for lifelong disease management in patients with phenylketonuria, a genetic disorder in which phenylalanine accumulates and persists at levels that alter brain development and cause permanent neurological damage and cognitive dysfunction. Recent approaches for treating phenylketonuria focus on injectable medications that efficiently break down phenylalanine but sometimes result in detrimentally low phenylalanine levels. We have identified new DNA aptamers for phenylalanine in two formats, initially as fluorescent sensors and then, incorporated with field-effect transistors (FETs). Aptamer-FET sensors detected phenylalanine over a wide range of concentrations (fM-mM). para-Chlorophenylalanine, which inhibits the enzyme that converts phenylalanine to tyrosine, was used to induce hyperphenylalaninemia during brain development in mice. Aptamer-FET sensors were specific for phenylalanine vs para-chlorophenylalanine and differentiated changes in mouse serum phenylalanine at levels expected in patients. Aptamer-FETs can be used to investigate models of hyperphenylalanemia in the presence of structurally related enzyme inhibitors, as well as naturally occurring amino acids. Nucleic acid-based receptors that discriminate phenylalanine analogs, some that differ by a single substituent, indicate a refined ability to identify aptamers with binding pockets tailored for high affinity and specificity. Aptamers of this type integrated into field-effect transistors enable rapid, electronic, label-free phenylalanine sensing.

Background The progression and metastasis of pancreatic ductal adenocarcinoma (PDAC) is highly dependent on the tumour microenvironment. Most tumour-associated macrophages (TAMs) are M2 phenotype macrophages, which normally show anti-inflammatory functions in numerous disorders. Previously, we found that alternatively activated macrophages showed pro-inflammatory characteristics upon stimulation with hepatoma cell-derived debris; however, the molecular mechanism was unclear. Methods In vitro and in vivo experiments were employed to investigate the molecular mechanism. Using pancreatic cancer cell lines, mouse models and human tissues, we obtained a general picture of tumour cell-derived debris promoting metastasis of pancreatic cancer by inducing inflammation via TAMs. Results We showed that M2 macrophage-derived inflammation also exists in PDAC. Debris from PDAC cells induced potent IL-1β release by M2 macrophages via TLR4/TRIF/NF-κB signalling, and this effect was further boosted by IgG that was also derived from PDAC cells. Increased IL-1β promoted epithelial–mesenchymal transition and consequent metastasis of PDAC cells. A selective COX-2 inhibitor, celecoxib, enhanced the anti-tumoural efficacy of gemcitabine. Conclusions These data revealed a pro-inflammatory mechanism in PDAC, which indicated that IL-1β and COX-2 could be therapeutic targets of an anti-inflammatory strategy to treat PDAC.

A new methacrylate monomer containing ferrocene unit and disulfide bond, 2-((2-(methacryloyloxy)ethyl)disulfanyl)ethyl ferrocenecarboxylate (FcMAss), was prepared by subsequent esterification reaction with bis(2-hydroxyethyl) disulfide and methacryloyl chloride using ferrocenecarboxylic acid as starting material. A series of well-defined poly(2-((2-(methacryloyloxy)ethyl)disulfanyl)ethyl ferrocenecarboxylate) (PFcMAss) homopolymers with narrow molecular weight distributions (Mw/Mn

Control of product selectivity is a central yet challenging issue in catalysis chemistry, both in academia and industry. The ever-increasing market demand for ethene, together with relatively low ethene selectivity, necessitates the upgrading of the current methanol-to-olefins (MTO) industry to enhance ethene selectivity. We report here an operable strategy, 1-butene “precoking” technology, by which ethene selectivity has been unprecedentedly enhanced while the catalyst lifespan has been conserved. We also made effects to provide more insight into the long-standing controversies regarding the mechanistic origin of the increase in ethene selectivity. With the aid of a 12C-/13C-methanol switch experiment, MD calculations, and FTIR analysis, it was demonstrated that ethene increase is neither simply—or solely—caused by the configurational diffusion effect, nor due to the transition-state shape selectivity or methylnaphthalene species, but rather to the spatial siting of the presituated “coke”. The relatively evenly distributed presituated coke extends the reaction zone toward the near-core of the SAPO-34 crystal, elongating the diffusion trajectories of molecules and allowing more acid sites to be utilized. The diffusion-hindered higher olefinic intermediates tend to evolve to active aromatic species, which, in turn, lead substantially to ethene. This mechanistic understanding could be also applicable to explaining ethene increase with time on stream (TOS) on parent SAPO-34.

There is urgent demand for the design of advanced coating materials for solid-phase microextraction (SPME) for water quality monitoring and assessment because of the global occurrence of chlorobenzenes (CBs). In this study, we proposed a dual-order activation method in which potassium hydroxide is used to modify pre-activated calcium citrate to synthesize a highly developed meso-/microporous carbon (MMC). The as-obtained MMC presented well-developed porosity with a super-high specific surface area (2638.09 m2 g−1), abundant meso-/micropores (0.5–10 nm), high hydrophobicity, excellent thermal stability (>720 °C), and a partly graphitized structure. As a coating material for headspace-SPME, the MMC-coated fiber exhibited outstanding extraction capability for CBs (up to 48.5 times higher than that of commercial fibers), which may be attributed to multiple interactions between the MMC and the pollutants, including size selectivity, micropore filling, π-π stacking and hydrophobicity. Finally, a satisfactory method using an MMC-coated fiber coupled with gas chromatography and electron capture detection was developed with good linearity (1–1000 ng L−1, R2 > 0.9982), high enrichment efficiencies (enrichment factors, 861–7819), low limits of detection (0.003–0.072 ng L−1), excellent repeatability (0.7–5.3%) and reproducibility (1.7–5.1%), and outstanding recoveries (90.18–103.02%) when applied to determine trace CBs in real water samples. These results suggest that MMC is a promising coating material for the SPME of CBs.

Oxygen nonstoichiometry plays a critical role in determining the physical and chemical functionalities of oxide materials. For widespread applications involving oxygen transport and exchange with t...

Ubiquitination is an enzymatic post-translational modification that affects protein fate. The ubiquitin-proteasome system (UPS) was first discovered in reticulocytes where it plays important roles in reticulocyte maturation. Recent studies have revealed that ubiquitination is a dynamic and reversible process and that deubiquitylases are capable of removing ubiquitin from their protein substrates. Given the fact that the UPS is highly active in reticulocytes, it is speculated that deubiquitylases may play important roles in erythropoiesis. Yet, the role of deubiquitylases in erythropoiesis remains largely unexplored. In the present study, we found that the expression of deubiquitylase USP7 is significantly increased during human terminal erythroid differentiation. We further showed that interfering with USP7 function, either by short hairpin RNA-mediated knockdown or USP7-specific inhibitors, impaired human terminal erythroid differentiation due to decreased GATA1 level and that restoration of GATA1 levels rescued the differentiation defect. Mechanistically, USP7 deficiency led to a decreased GATA1 protein level that could be reversed by proteasome inhibitors. Furthermore, USP7 interacts directly with GATA1 and catalyzes the removal of K48-linked poly ubiquitylation chains conjugated onto GATA1, thereby stabilizing GATA1 protein. Collectively, our findings have identified an important role of a deubiquitylase in human terminal erythroid differentiation by stabilizing GATA1, the master regulator of erythropoiesis.

Background Calcium is an essential macronutrient for plant growth. Although it has been shown that exogenous Ca application can increase plant resistance to abiotic stress, little is known about its potential to enhance plant tolerance to biotic stress. Here, we investigated whether pretreatment of wheat (Triticum aestivum L.) seeds with calcium chloride (CaCl2 ) improves plant resistance against wheat aphid (Schizaphis graminum Rondani). The developmental time, population size, feeding behavior of aphids on plants grown from CaCl2 - and water-pretreated seeds, and plant defense responses to aphid attack were investigated. Results Seed pretreatment with CaCl2 extended aphid development time and reduced aphid population size and feeding efficiency. In addition, the pretreatment significantly increased the concentration of Ca2+ in wheat leaves, and upregulated expression levels of TaCaM genes and callose synthase genes (TaGSL2, TaGSL8, TaGSL10, TaGSL12, TaGSL19, TaGSL22 and TaGSL23). Callose concentration in the leaves of plants grown from CaCl2 -pretreated seeds increased significantly upon aphid attack. Further, callose deposition was observed mainly in the phloem. Conclusion These results suggest that seed pretreatment with CaCl2 primes the plant response against wheat aphid attack, leading to modulation of callose deposition in the phloem in response to aphid attack. © 2021 Society of Chemical Industry.

Organochlorine pesticides (OCPs) contaminated sites pose great threats to both human health and environmental safety. Targeted bioremediation in these regions largely depends on microbial diversity and activity. This study applied metagenomics to characterize the microbial communities and functional groups composition features during independent or simultaneous rapeseed oil and tartaric acid applications, as well as the degradation kinetics of OCPs. Results showed that: the degradation rates of α-chlordane, β-chlordane and mirex were better when (0.50% w/w) rapeseed oil and (0.05 mol L-1) tartaric acid were applied simultaneously than singular use, yielding removal rates of 56.4%, 53.9%, and 49.4%, respectively. Meanwhile, bio-stimulation facilitated microbial enzyme (catalase/superoxide dismutase/peroxidase) activity in soils significantly, promoting the growth of dominant bacterial communities. Classification at phylum level showed that the relative abundance of Proteobacteria was significantly increased (p < 0.05). Network analysis showed that bio-stimulation substantially increased the dominant bacterial community's proportion, especially Proteobacteria. The functional gene results illustrated that bio-stimulation facilitated total relative abundance of degradation genes, phosphorus, carbon, nitrogen, sulfur metabolic genes, and iron transporting genes (p < 0.05). In metabolic pathways, functional genes related to methanogenesis and ammonia generation were markedly upregulated, indicating that bio-stimulation promoted the transformation of metabolic genes, such as carbon and nitrogen. This research is conducive to exploring the microbiological response mechanisms of bio-stimulation in indigenous flora, which may provide technical support for assessing the microbial ecological remediation outcomes of bio-stimulation in OCP contaminated sites.

Insecticide exposure typically leads to abnormally high levels of reactive oxygen species (ROS) and oxidative damage in insects. Superoxide dismutases (SODs) are potent antioxidant enzymes for ROS scavenging that are essential to protect insects against insecticide-induced oxidative injury. The small white butterfly, Pieris rapae, is an economically important lepidopteran pest of cruciferous crops, and the anthranilic diamide insecticide chlorantraniliprole is widely used to control this organism. However, whether chlorantraniliprole causes oxidative stress, and whether SODs are involved in ROS scavenging, remains unclear in P. rapae. In this study, an intracellular copper/zinc SOD (designated PrSOD1) gene was identified and characterised in P. rapae. The gene consists of four exons and three introns, and the PrSOD1 protein encoded by the gene has typical highly conserved features of CuZnSODs, including two signature motifs and seven Cu/Zn-interacting residues. Transcription of PrSOD1 was highest in the larval fat body and at the fifth-instar larval stage. Recombinant PrSOD1 protein expressed in Escherichia coli displayed antioxidant activity and high thermal and pH stability, confirming that PrSOD1 encodes a functional enzyme. Exposure to three sublethal doses of chlorantraniliprole for 6, 12 or 24 h resulted in significantly increased malondialdehyde concentration in P. rapae larvae, indicating insecticide-induced oxidative stress. Furthermore, both PrSOD1 transcription levels and CuZnSOD activity were quickly (6 and 12 h, respectively) upregulated in larvae subjected to chlorantraniliprole, strongly suggesting that PrSOD1 plays an important role in protecting against oxidative damage and possibly chlorantraniliprole tolerance in P. rapae.

Apoptosis is programmed cell death that can be stimulated by external stress or nutrition restrictions. Lysine (Lys) is an essential amino acid for pig growth, and the relationship between Lys deficiency caused apoptosis and inhibition of skeletal muscle growth remains unknown. The objective of this study was to investigate whether apoptosis could be regulated by Lys supplementation and the potential mechanism. In current work, 30 male Duroc × Landrace × Large weaned piglets were divided randomly into 3 groups: control group (Lys 1.30%), Lys deficiency group (Lys 0.86%), and Lys rescue group (Lys 0.86%, 0-14d; 1.30%,15–28 d). The experiment lasted for 28 days, and on the morning of 29 d, piglets were slaughtered to collect samples. Isobaric tag for relative and absolute quantification (iTRAQ) proteomics analysis of the longissimus dorsi muscle showed that Janus family tyrosine kinase (JAK)-signal transducer and activator of transcription (STAT) pathway was involved in Lys deficiency-induced apoptosis and inhibited skeletal muscle growth. Meanwhile, western blotting results of the longissimus dorsi muscle demonstrated that Lys deficiency caused apoptosis (P < 0.05) with the JAK2-STAT3 pathway inhibition (P < 0.05). Interestingly, apoptosis was suppressed (P < 0.05), and the JAK2-STAT3 pathway was reactivated (P < 0.05) after Lys re-supplementation in longissimus dorsi muscle. In addition, results of satellite cells (SCs) isolated from the longissimus dorsi muscle of 5-day-old Landrace piglets showed that Lys deficiency-induced apoptosis (P < 0.05) was mediated by the JAK2-STAT3 pathway inhibition (P < 0.05). Moreover, the JAK2-STAT3 pathway was reactivated (P < 0.05) by Lys re-supplementation and suppressed apoptosis in SCs (P < 0.05), and this effect was blocked (P < 0.05) after SCs treated with AG-490 (a specific inhibitor of JAK2). Collectively, Lys inhibited apoptosis in SCs to govern skeletal muscle growth via the JAK2-STAT3 pathway.

Chlordane is an organochlorine pesticide that is applied extensively. Residual concentrations that remain in soils after application are highly toxic to soil organisms, particularly affecting the earthworm gut and indigenous soil microorganisms. However, response mechanisms of the earthworm gut and indigenous soil microorganism communities to chlordane exposure are not well known. In this study, earthworms (Metaphire guillelmi) were exposed to chlordane-contaminated soils to investigate their response mechanisms over a gradient of chlordane toxicity. Results from high-throughput sequencing and network analysis showed that the bacterial composition in the earthworm gut varied more significantly than that in indigenous soil microbial communities under different concentrations of chlordane stress (2.3–60.8 mg kg−1; p

Sodium metal batteries are widely acknowledged as one of the most promising low-cost high-energy-density batteries, but limited by uncontrollable dendritic growth and short cyclability. Herein, two-dimensional (2D) mesoporous polydopamine-graphene (mPG) heterostructures with definable pore size and sheet thickness are demonstrated as multi-functional ion redistributors to realize ultrastable, dendrite-free Na metal anodes. Benefitting from abundant sodiophilic groups (-OH, C=O and -NH-), 2D nanoporous graphene, and ordered mesoporous ion channels in mPG, the Na metal anodes show high Coulombic efficiency of >99.5%, outstanding cyclability of ~2000 h, and unprecedented rate performance of 25 mA cm-2 with 25 mAh cm-2, outperforming all the reported Na anodes stabilized by diversified strategies. What’s more, the mPG based Na/Na3V2(PO4)3 full batteries deliver exceptionally enhanced cyclability (90% retention rate after 500 cycles) and rate capacity (75 mAh g-1 at 30 C), demonstrative of impressive potential of well-designed 2D mesoporous polymers for precisely regulating Na deposition.

Hydrogen peroxide (H2O2) is an important mediator in biological medicine, disease diagnosis and environmental analyses and therefore it is essential to develop a detection approach for H2O2 in physical environments. Herein, we designed and prepared a series of AuNP-containing nanocomposites (AuNPs@NGO-PEG, AuNPs@G1-PAMAM-NGO-PEG and AuNPs@G3-PAMAM-NGO-PEG) for enhanced non-enzymatic H2O2 detection. We firstly demonstrated functionalized nanographene oxide (NGO) based materials, which combined advantages of biocompatible poly(ethylene glycol) (PEG), hyperbranched polyamidamine (PAMAM) dendrimer and thiol active site, as compatible platforms. Gold nanoparticles (AuNPs) were then aptly in situ grown on these functionalized NGO based materials via the reduction of HAuCl4 under mild conditions, i.e. AuNPs@NGO-PEG, AuNPs@G1-PAMAM-NGO-PEG and AuNPs@G3-PAMAM-NGO-PEG nanocomposites, which possess stable and uniform AuNPs standing on the functionalized NGO sheets. For H2O2 detection, these nanocomposites were cast on a glassy carbon electrode (GCE) conveniently, i.e. GCE/AuNPs@NGO-PEG, GCE/AuNPs@G1-PAMAM-NGO-PEG and GCE/AuNPs@G3-PAMAM-NGO-PEG. It is evident that these GCEs could be applied as efficient non-enzymatic H2O2 detectors resulting from the corresponding cyclic voltammetric curves and typical ready-state amperometric curves. GCE/AuNPs@G1-PAMAM-NGO-PEG exhibited the fastest electron transfer rate among these modified GCEs. We envisage that these GCEs could provide efficient sensors for H2O2 detection and a new strategy for sensor design.

Direct visualization of spatiotemporal evolution of molecules and active sites during chemical transformation in individual catalyst crystal will accelerate the intuitive understanding of heterogeneous catalysis. So far, widespread imaging techniques can only provide limited information either with large probe molecules or in model catalyst of large size, which are beyond the interests of industrial catalysis. Herein, we demonstrate a feasible deep data approach via synergy of multiscale reaction-diffusion simulation and super-resolution structured illumination microscopy to illustrate the dynamical evolution of spatiotemporal distributions of gas molecules, carbonaceous species and acid sites in SAPO-34 zeolite crystals of several micrometers that are typically used in industrial methanol-to-olefins process. The profound insights into the inadequate utilization of activated acid sites and rapid deactivation are unveiled. The notable elucidation of molecular reaction-diffusion process at the scale of single catalyst crystal via this approach opens an interesting method for mechanism study in materials synthesis and catalysis., Imaging zeolites in catalysis relies on the use of probe molecules or model catalysts. Here the authors show the synergy of a multiscale reaction-diffusion model and structured illumination microscopy to illustrate spatiotemporal evolution of molecules and acid sites in SAPO-34 zeolites in methanol-to-olefins reaction.

Mass transfer of guest molecules has a significant impact on the applications of nanoporous crystalline materials and particularly shape-selective catalysis over zeolites. Control of mass transfer to alter reaction over zeolites, however, remains an open challenge. Recent studies show that, in addition to intracrystalline diffusion, surface barriers represent another transport mechanism that may dominate the overall mass transport rate in zeolites. We demonstrate that the methanol-to-olefins (MTO) reaction can be modulated by regulating surface permeability in SAPO-34 zeolites with improved chemical liquid deposition and acid etching. Our results explicitly show that the reduction of surface barriers can prolong catalyst lifetime and promote light olefins selectivity, which opens a potential avenue for improving reaction performance by controlling the mass transport of guest molecules in zeolite catalysis.

Apoptosis is programmed cell death that can be stimulated by external stress or nutrition restrictions. However, the precise mechanism of apoptosis in skeletal muscle remains unknown. The objective of this study was to investigate whether apoptosis could be regulated by lysine (Lys) supplementation and the potential mechanism. In this study, an isobaric tag for relative and absolute quantification (iTRAQ) proteomics analysis of the longissimus dorsi muscle from piglets showed that the Janus family tyrosine kinase (JAK)-signal transducer and activator of transcription (STAT) pathway was involved in Lys deficiency-induced apoptosis and inhibited skeletal muscle growth. Meanwhile, western blotting results demonstrated that Lys deficiency led to apoptosis in the longissimus dorsi muscle with the JAK2-STAT3 pathway inhibition. Interestingly, apoptosis was suppressed, and the JAK2-STAT3 pathway was reactivated after Lys re-supplementation. In addition, the results showed that Lys deficiency-induced apoptosis in satellite cells (SCs) was mediated by the JAK2-STAT3 pathway inhibition. Moreover, the JAK2-STAT3 pathway was reactivated by Lys re-supplementation and suppressed cell apoptosis, and this effect was inhibited after treatment with Tyrphostin B42 (AG 490). In conclusion, we found that Lys inhibits apoptosis in SCs to govern skeletal muscle growth via the JAK2-STAT3 pathway.

Guiding the lithium ion (Li-ion) transport for homogeneous, dispersive distribution is crucial for dendrite-free Li anodes with high current density and long-term cyclability, but remains challenging for the unavailable well-designed nanostructures. Herein, we propose a two-dimensional (2D) heterostructure composed of defective graphene oxide (GO) clipped on mesoporous polypyrrole (mPPy) as a dual-functional Li-ion redistributor to regulate the stepwise Li-ion distribution and Li deposition for extremely stable, dendrite-free Li anodes. Owing to the synergy between the Li-ion transport nanochannels of mPPy and the Li-ion nanosieves of defective GO, the 2D mPPy-GO heterostructure achieves ultralong cycling stability (1000 cycles), even tests at 0 and 50 °C, and an ultralow overpotential of 70 mV at a high current density of 10.0 mA cm-2 , outperforming most reported Li anodes. Furthermore, mPPy-GO-Li/LiCoO2 full batteries demonstrate remarkably enhanced performance with a capacity retention of >90 % after 450 cycles. Therefore, this work opens many opportunities for creating 2D heterostructures for high-energy-density Li metal batteries.

Chalcogenide phase-change materials show strikingly contrasting optical and electrical properties, which has led to their extensive implementation in various memory devices. By performing spin-, time-, and angle-resolved photoemission spectroscopy combined with the first-principles calculation, we report the experimental results that the crystalline phase of GeSb2Te4 is topologically nontrivial in the vicinity of the Dirac semimetal phase. The resulting linearly dispersive bulk Dirac-like bands that cross the Fermi level and are thus responsible for conductivity in the stable crystalline phase of GeSb2Te4 can be viewed as a 3D analogue of graphene. Our finding provides us with the possibility of realizing inertia-free Dirac currents in phase-change materials., The ARPES experiments were performed with the approval of the Proposal Assessing Committee of HSRC (Proposal No. 18BG039). The TARPES measurements were jointly carried out by the Laser and Synchrotron Research Center of the Institute for Solid State Physics at the University of Tokyo. This work was financially supported by KAKENHI (Grant No. 17H06138, No. 17H06152, No. 18H03683, No. 18H01148). This work was also supported by the ‘‘Tomsk State University competitiveness improvement programme’’ (Project No. 8.1.01.2018), by Saint Petersburg State University (Project ID 51126254), and by Russian Science Foundation No. 17-12-01047 (in the crystal growth part). T.V.M. and I.P.R. acknowledge support from Ministry of Education and Science of the Russian Federation (State Task No. 0721-2020-0033) (study of intermixed crystalline phase of GST-124). Calculations were performed at the SKIF-Cyberia supercomputer of Tomsk State University (Russian Federation). K.A.K. acknowledges RFBR Grant 17-08-00955 and a state contract of IGM SB RAS.

Lambda-cyhalothrin (LCT) is a pyrethroid insecticide widely used to control insect pests. Insect exposure to LCT may cause abnormal accumulation of reactive oxygen species (ROS) and result in oxidative damage. Heat shock proteins (HSPs) may help protect against oxidative stress. However, little is known about the role of HSPs in response to LCT in the green peach aphid, Myzus persicae. This insect is an important agricultural pest causing severe yield losses in crops. In this study, we characterized a cDNA sequence (MpHsp70) encoding a member of the HSP70 family in M. persicae. MpHsp70 encoded a 623 amino acid protein putatively localized in the cytosol. The highest expression level of MpHsp70 occurred in fourth-instar nymphs. Treatment of M. persicae with LCT resulted in oxidative stress and significantly increased H

Mass transfer of guest molecules is crucial for zeolite catalysis. Compared to intracrystalline diffusion, the surface barriers in zeolite catalysis have been less understood. Taking furfuryl alcohol oligomerization catalyzed by ZSM-5 zeolites as model reaction, here we present a single-crystal level study and gain insight into the surface barriers induced spatiotemporal evolution of oligomer products using structured illumination microscopy (SIM). It is shown that, as a result of the enhanced accessibility to zeolite crystals, promoting the surface permeability leads to the increase in catalytic reaction rate that is characterized as the generation rate of oligomer products.

The methanol-to-olefins (MTO) reaction over the SAPO-34 catalyst suffers rapid deactivation due to coke deposition. Here, partial regeneration methods with air combustion and steam gasification were investigated. The results showed that both methods could not only reactivate the spent SAPO-34 catalyst but also prompt ethylene selectivity. Whereas, steam gasification was more effective , by which the initial ethylene selectivity could reach 53%, much higher than that of 23% over fresh SAPO-34 catalyst. Several characterizations, e.g., Fourier transform infrared spectroscopy and gas chromatography–mass spectrometry, indicated that methylated benzenes, which were active hydrocarbon pool species and prompted ethylene selectivity, presented as the main species of residual coke in the SAPO-34 catalyst regenerated via steam gasification. Meanwhile, oxygenated compounds and naphthalene, which could accelerate catalyst deactivation, were observed in the SAPO-34 catalyst partially regenerated via air combustion. Th...

Esterase is an industrial enzyme that is widely used in food, medicine, fine chemicals. The total genomic DNA was extracted from traditional fermented food in China to construct a metagenomic library that included a novel esterase gene (est_115). Sequence homology analysis showed that the highest homology with the carboxylester hydrolase from Pseudomonas lutea was 38%, indicating that esterase belongs to a new class of esterases. Then, an est_115 gene recombinant expression vector was constructed and expressed. The Est_115 had higher catalytic activity to p-nitrophenol ester, with a short acyl-carbon chain. The enzyme can maintain high catalytic activity and salt tolerance in 10%–18% NaCl, suggesting that this novel esterase can be used in processing food using high osmotic pressure.

In the methanol-to-olefins (MTO) process, coke deposition is closely related to the selectivity of light olefins. Previous simulations of different-sized MTO reactors using two-fluid model (TFM) combined with the EMMS (energy minimization multi-scale)-based drag well predict the hydrodynamic behaviors but poorly predict the product distribution of large reactors due to the unreasonable prediction in coke distribution. In this study, the TFM integrated with the EMMS-based drag is still employed, but the solid phase is treated as a mixture of a series of species with different coke contents. Because the coke content depends on the age of catalyst particles inside the reactor, a continuous stirred tank reactor (CSTR) model mimicking turbulent fluidization while considering the age distribution of catalysts is established to predict the initial coke distribution for speeding up simulation. Compared with the previous simulation without consideration of coke distribution, this approach increases the computational time by a factor of 36% and shows no influence on hydrodynamic predictions, but the reaction quantities such as methanol conversion, mass fractions of gaseous products and selectivity of light olefins, are better predicted.