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•CuZnO/Al2O3/Al catalysts exhibit superior activity and stability in MSR.•Self-activation-induced ZnO encapsulation of copper nanoparticles is first discovered.•The optimal Cu+/Cu0 ...ratio allows a remarkable improvement of the MSR activity.•Cu2O/ZnO synergistic sites significantly reduce the activation energy barrier of the rate-determining step.
The CuZnO catalyst with excellent low-temperature catalytic activity is widely used in methanol steam reforming (MSR). Here, a series of CuZnO/γ-Al2O3/Al catalysts were prepared by a two-step impregnation method using structured γ-Al2O3/Al support. The unique synergistic effect of Cu2O/ZnO on MSR was found by the experimental and numerical investigation. The experimental characterization results show that the decoration of ZnO can regulate the content of Cu+ on the catalytic surface, and the increase of Cu+ shortens the self-activation response time of the catalyst. During the self-activation process, ZnO-encapsulated Cu nanoparticles (Cu NPs) surface induced by strong metal-support interaction (SMSI) was observed. The encapsulation not only inhibited the agglomeration of Cu NPs but also formed a large number of new Cu2O/ZnO synergistic sites. Furtherly, the numerical calculation show that the Cu2O/ZnO synergistic sites significantly reduced the activation energy of methoxy dehydrogenation (the rate-determining step of MSR).
Perovskite‐structured (ABO3) transition metal oxides are promising bifunctional electrocatalysts for efficient oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). In this paper, a ...set of epitaxial rare‐earth nickelates (RNiO3) thin films is investigated with controlled A‐site isovalent substitution to correlate their structure and physical properties with ORR/OER activities, examined by using a three‐electrode system in O2‐saturated 0.1 m KOH electrolyte. The ORR activity decreases monotonically with decreasing the A‐site element ionic radius which lowers the conductivity of RNiO3 (R = La, La0.5Nd0.5, La0.2Nd0.8, Nd, Nd0.5Sm0.5, Sm, and Gd) films, with LaNiO3 being the most conductive and active. On the other hand, the OER activity initially increases upon substituting La with Nd and is maximal at La0.2Nd0.8NiO3. Moreover, the OER activity remains comparable within error through Sm‐doped NdNiO3. Beyond that, the activity cannot be measured due to the potential voltage drop across the film. The improved OER activity is ascribed to the partial reduction of Ni3+ to Ni2+ as a result of oxygen vacancies, which increases the average occupancy of the eg antibonding orbital to more than one. The work highlights the importance of tuning A‐site elements as an effective strategy for balancing ORR and OER activities of bifunctional electrocatalysts.
Bifunctional oxygen electrocatalysts of perovskite nickelates thin films can be tuned by changing A‐site rare‐earth elements. Oxygen reduction reaction activity decreases monotonically with decreasing the A‐site element ionic radius. Oxygen evolution reaction (OER) activity initially increases upon substituting La with Nd and is maximal at La0.2Nd0.8NiO3. Further decreasing of the average A‐site radius by mixing Nd and Sm gives comparable OER activity to NdNiO3.
The number of patents increases quickly, while more and more low-quality patents are emerging. It's important to identify high-quality patents from massive data quickly and accurately for ...organizational R&D decision-making and patent layout. However, due to low percentage of high-quality patents, it is challenging to identify them efficiently. In order to solve above problem, we reconstruct the existing index system for identifying high-quality patents by adding 4 features from technological strength of patentees. Furthermore, we propose an improved model by integrating resampling technique and ensemble learning algorithm. First, generative adversarial networks (GAN) are used to expand minority samples. Second, Extreme Gradient Boosting algorithm (XGBoost) with Bayesian optimization (BO) is used to identify high-quality patents. For clarity, this model is called a GAN-BO-XGBoost model. To test the effectiveness of above model, we use patent data in field of lithography technology. Tenfold cross-validation is carried out to evaluate the performance between our proposed model and other models. The results show that GAN-BO-XGBoost model performs better and it's more stable than other models.
Tartary buckwheat (Fagopyrum tataricum Gaertn.) is a coarse cereal with strongly abiotic resistance. The MYB family plays a regulatory role in plant growth, development, and responses to biotic and ...abiotic stresses. However, the characteristics and regulatory mechanisms of MYB transcription factors in Tartary buckwheat remain unclarified. Here, this study cloned the FtMYB22 gene from Tartary buckwheat, and investigated its involvement in responding to individual water deficit and salt stress in Arabidopsis. Sequence analysis highlighted that the N-termini of FtMYB22 contained two highly conserved SANT domains and one conserved domain from the SG20 subfamily. Nucleus-localized FtMYB22 did not have individual transcriptional activation activity. Water deficiency and salt stress induced the high expression of the GUS gene, which was driven by the promoter of FtMYB22. Yeast stress experiments showed that the overexpression of FtMYB22 significantly reduced the growth activity of transgenic yeast under water deficit or salt stress. Consistently, the overexpression of FtMYB22 reduced the salt and water deficit stress resistance of the transgenic plants. In addition, physiological parameters showed that transgenic plants had lower proline and antioxidant enzyme activity under stress conditions. Compared to the wild-type (WT), transgenic plants accumulated more malondialdehyde (MDA), H2O2, and O2−; they also showed higher ion permeability and water loss rates of detached leaves under stress treatments. Notably, FtMYB22 was involved in plant stress resistance through an ABA-dependent pathway. Under stress conditions, the expression of RD29A, RD29B, PP2CA, KIN1, COR15A, and other genes in response to plant stress in transgenic lines was significantly lower than that in the WT (p < 0.05). Furthermore, yeast two-hybrid assay showed that there was a significant interaction between FtMYB22 and the ABA receptor protein RCAR1/2, which functioned in the ABA signal pathway. Altogether, FtMYB22, as a negative regulator, inhibited a variety of physiological and biochemical reactions, affected gene expression and stomatal closure in transgenic plants through the ABA-dependent pathway, and reduced the tolerance of transgenic Arabidopsis to water deficiency and salt stress. Based on these fundamental verifications, further studies would shed light on the hormone signal response mechanism of FtMYB22.
Inducible nitric oxide synthase (iNOS), accompanied with protumor and antitumor activity, has been studied in multiple cancers. However, the role of iNOS expression in osteosarcoma (OS) is far from ...being fully understood. In present work, iNOS levels were detected in OS tissues and cell lines. Colony formation assay, Transwell assay, and fow cytometer were used to assess proliferation, migration, invasion, and apoptosis abilities in vitro after iNOS inhibition. Western blotting determined the expressions of iNOS, MMP2, MMP9, C-MYC, Ki67, PCNA, and β-catenin. Mice transfected with OS cells were to evaluate tumor formation. IHC assay was to evaluate the expressions of iNOS and β-catenin in mice. The results showed that iNOS was upregulated in both OS tissues and cells compared with that in matched normal tissues or cells. And we found that proliferation, migration, and invasion numbers of OS cells were decreased, and apoptosis numbers of OS cells were increased after iNOS inhibition. MMP2, MMP9, C-MYC, Ki67, and PCNA levels were also reduced in OS cells treated with iNOS inhibition. Else, iNOS inhibition would suppress β-catenin expression in OS cells to regulate MMP2, MMP9, C-MYC, Ki67, and PCNA expressions. In addition, tumor formation, iNOS expression, and β-catenin expression were inhibited in mice transplanted with iNOS knockout OS cells. These results indicated that iNOS might be a potential therapeutic target for OS.
Mercury chloride can cause severe liver injury, which involves multiple mechanisms. Ferroptosis plays an important role in regulating the development and progression of liver pathology. Oleanolic ...acid (OA), a triterpenoid compound widely exists in fruits, has liver protective properties. In this study, we investigated the role of ferroptosis in mercury chloride-induced liver injury and the intervention effect of OA, and clarified the potential mechanism. We found that mercury chloride-induced oxidative stress in liver tissues and cells, leading to lipid peroxidation and iron overload, thereby reducing the expression levels of GPX4 and SLC7A11, and increasing the expression level of TRF1, OA pretreatment improved the changes of GPX4, SLC7A11 and TRF1 induced by mercury chloride, which were related to its inhibition of oxidative stress. Furthermore, We pretreated cells with OA, VC, and Fer-1, respectively and found that VC pretreatment reduced oxidative stress and significantly reversed the gene and protein expressions of GPX4, SLC7A11, and TRF1 in mercury chloride-exposed cells (P < 0.05, vs. HgCl2 group), however, the protein expression level of GPX4 in OA pre-treatment group was lower than that in VC pre-treatment group (P < 0.05). Fer-1 pretreatment decreased the level of iron ions in cells, increased the gene and protein expression levels of GPX4 and SLC7A11, and decreased the gene and protein expression levels of TRF1 (P < 0.05, vs. HgCl2 group), however, the protein expression levels of GPX4 and SLC7A11 in OA pre-treatment group were lower than those in Fer-1 pre-treatment group (P < 0.05). Moreover, vivo experiments also demonstrated that pre-treatment with OA, VC, and Fer-1 reversed the changes in gene expression levels of Nrf2 and SOD1, and protein expression of GPX4 induced by mercury chloride (P < 0.05, vs. HgCl2 group), meanwhile, the difference was not statistically significant among OA, VC, and Fer-1 pretreatment. The improvement effect of OA pretreatment on the change in TFR1 protein expression caused by mercury chloride was similar to that of Fer-1 and VC, however, the intervention effect of OA on SLC7A11 protein expression was not as good as Fer-1 and VC pre-treatment. To sum up, all these results suggest that ferroptosis is involved in mercury chloride-induced liver injury, OA pretreatment alleviated mercury chloride-induced ferroptosis by inhibiting ROS production and iron ion overload, and then alleviate the liver injury.
•Mercury chloride induces liver injury, involving ferroptosis.•OA improves mercury chloride-induced liver injury is related to the inhibition of iron overload.•Inhibited ROS/iron overload play a key role in ameliorated mercury chloride-induced liver injury.
Organo-montmorillonite (OMt) is widely used in oil well drilling fluids, paint, grease, cosmetics, and personal care products. Nanocomposites which are prepared using organoclays and polymers. ...Generally, organo-montmorillonite can be prepared using ion-exchange reactions with cationic surfactants. However, cationic-organo-montmorillonite (COMt) has poorer thermal stability. In addition, the preparation process of traditional OMt uses a large amount of water. The process would emit a large amount of effluent and increase cost.
The aim of this work is to prepare nonionic-organo-montmorillonite (NOMt) and anionic-nonionic-organo-montmorillonite (ANOMt) using ball milling method. And NOMt and ANOMt are of better thermal stability than COMt.
Organo-montmorillonite was prepared using ball milling method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), Thermogravimetric (TG) analysis, differential thermal analysis (DTA) and contact angle test.
XRD analysis indicated that the interlayer spacing of Ca2+-montmorillonite (Ca-Mt) was expanded. ANOMt showed a large d-spacing above 5.0nm. SEM analysis demonstrated that the ANOMt was flaky in substance. FT-IR spectra proved that the chemical environment of the surfactants changed. TG and DTA results showed that the thermal stabilities of NOMt and ANOMt were better than that of COMt. FT-IR and thermal analysis indicated that the interlayer water was replaced. The contact angle tests of the samples indicated that NOMt and ANOMt were of oleophilic property.
Ca-Mt was modified with nonionic surfactant and anionic surfactant by ball milling method, without any added water. NOMt and ANOMt were prepared. The thermal stabilities of NOMt and ANOMt are better than COMt. Dual mechanisms of intercalation and stacking were proposed.
•New organo-montmorillonites were prepared by ball milling.•Their thermal stabilities were better than that of cationic-organo-montmorillonite.•The first d-spacings exceeded 5.0nm.•The preparation process was water-free, simple, environmentally friendly.•Dual mechanisms of intercalation and stacking were proposed.
Zinc deficiency can change the concentrations of minerals and trace elements in the body. However, previous studies still had many limitations.
To reveal the effects of zinc deficiency on homeostasis ...of 16 minerals and trace elements.
Forty-five rats were divided randomly into three groups: normal zinc diet (30 mg/kg), low zinc diet (10 mg/kg), and pair-fed diet(30 mg/kg). The concentrations of 16 minerals and trace elements in serum, feces, urine, and liver were measured by inductively coupled plasma mass spectrometry. The excretion of 16 elements in urine and feces were calculated and compared.
Zinc-deficient rats exhibited significant changes in up to 12 minerals and trace elements. The low zinc diet induced decreased excretion of zinc and concentrations of zinc in serum, feces, urine, and liver. Zinc deficiency increased feces concentrations of Mg, Cu, Se, K, Ag, Fe and Mn; decreased the concentrations of Mg, Cu, Se, K in liver and urine, and a diminished amount of Ag was observed in serum. Decreased urinary concentrations of Zn Ca, Mg, Cu, Se, K, Na, As and Cr, suggested that zinc-deficient rats increased the 9 elements' renal reabsorption. Decreased concentrations of Ca in liver, urine, and feces, decreased excretion in urine and feces and increased serum total Ca suggested that zinc deficiency increased the redistribution of Ca in serum or other tissues. Zinc deficiency increased excretion of Cu, Se, Fe; and decreased the excretion of other 8 elements except for Ag.
Zinc deficiency changed the excretion, reabsorption and redistribution of 12 minerals and trace elements in rats. Our findings are the first to show that zinc deficiency alters the concentrations of Ag, Cr, and As.
accompanies this paper at 10.1186/s12986-019-0395-y.
Due to the high drug resistance of hepatocellular carcinoma (HCC), sorafenib has limited efficacy in the treatment of advanced HCC. Cancer-associated fibroblasts (CAFs) play an important regulatory ...role in the induction of chemoresistance. This study aimed to clarify the mechanism underlying CAF-mediated resistance to sorafenib in HCC.
Immunohistochemistry and immunofluorescence showed that the activation of CAFs was enhanced in HCC tissues. CAFs and paracancerous normal fibroblasts (NFs) were isolated from the cancer and paracancerous tissues of HCC, respectively. Cell cloning assays, ELISAs, and flow cytometry were used to detect whether CAFs induced sorafenib resistance in HCC cells via CXCL12. Western blotting and qPCR showed that CXCL12 induces sorafenib resistance in HCC cells by upregulating FOLR1. We investigated whether FOLR1 was the target molecule of CAFs regulating sorafenib resistance in HCC cells by querying gene expression data for human HCC specimens from the GEO database.
High levels of activated CAFs were present in HCC tissues but not in paracancerous tissues. CAFs decreased the sensitivity of HCC cells to sorafenib. We found that CAFs secrete CXCL12, which upregulates FOLR1 in HCC cells to induce sorafenib resistance.
CAFs induce sorafenib resistance in HCC cells through CXCL12/FOLR1.
A stitching linear scan method is proposed for roundness and diameter measurement of small cylindrical workpieces instead of the conventional rotary scan method due to the crucial alignments of ...eccentricity and inclination. To verify the reliability of the proposed method, by which the coordinates of the cross-sectional circle of a small cylinder is divided into several equal parts to be obtained and reconstructed, the diameter and roundness measurement uncertainties of the small cylinders with a diameter 1.5 mm are evaluated to be 0.047 μm and 0.095 μm, respectively, which can meet the uncertainty target of 0.1 μm. To investigate the measurable dimension by the proposed method, measurement uncertainty analysis of the small cylinders with various dimensions has been conducted according to the previous evaluation, since all the procedures are the same except for the uncertainty of X coordinates, which changes with the measured dimension’s change. The results show that the small cylinders with a diameter range from 0.01 mm to 50 mm can be measured by the proposed method when the position error θZ is reduced to the corresponding value. There is no measuring limitation set by the proposed model theoretically in the case of θX = θZ = 0.1°, while the machine has a measuring limitation.
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