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WO3 and MoO3 are often used as acidic promoters to modify vanadium based and non-vanadium based composite oxide catalysts, meanwhile, the NH3-SCR performance of the catalysts could be evidently improved. Generally, WO3 and MoO3 are believed to play the same role in V2O5-based and other composite oxide NH3-SCR catalysts. Interestingly, our recent work found that there are significant differences between WO3 and MoO3 in improving the NH3-SCR performance of CeZrOx. The operating temperature window of WO3/CeZrOx (222−454 °C) is 76 °C wider than that of MoO3/CeZrOx (254−410 °C) for NH3-SCR reaction. WO3/CeZrOx exhibits higher NOx removal efficiency than MoO3/CeZrOx in the whole temperature range. The similarities and differences in the effects of the acid promoters WO3 and MoO3 on the NH3-SCR performance of Ce-based catalysts are systematically investigated by Vis-Raman, XRD, XPS, NH3/O2/NOx-TPD, H2-TPR, NO/NH3-oxidation and in situ DRIFTS. Noteworthy, stronger interaction between MoO3 and CeZrOx than WO3 and CeZrOx leads to less oxygen vacancies and Lewis acid sites on the surface of MoO3/CeZrOx as well as strong oxidation property, which inhibit the NOx adsorption but contribute to the peroxidation of NH3 on MoO3/CeZrOx, reflecting its poor SCR activity. This work provides an in-depth understanding of the intrinsic effects of WO3 and MoO3 on the NH3-SCR performance of CeZrOx-based catalysts.

Stroke is a kind of cerebrovascular disease that heavily damages people’s life and health. The quantitative analysis of brain MRI images plays an important role in the diagnosis and treatment of stroke. Deep neural networks with massive data learning ability supply a powerful tool for lesion detection. In order to study the property of the stroke lesions and complete intelligent automatic detection, we collaborated with two authoritative hospitals and collected 5,668 brain MRI images of 300 ischemic stroke patients. All the lesion regions in the images were accurately labeled by professional doctors to ensure the authority and effectiveness of the data. Three categories of deep learning object detection networks including Faster R-CNN, YOLOV3, and SSD are applied to implement automatic lesion detection with the best precision of 89.77%. Meanwhile, statistical analysis of the locations, shapes of the lesions, and possible related diseases is conducted with valid conclusions. The research contributes to the intelligent assisted diagnosis and prevention and treatment of ischemic stroke.

WO3 has different crystalline structures, including monoclinic and hexagonal phases. Monoclinic WO3 (W-m) is the most common crystal phase in NH3-SCR catalysts. Hexagonal WO3 (W-h) with empty hexagonal and trigonal tunnel structures exhibits excellent acidity and reducibility and can provide abundant catalytically active sites, but it is hardly applied in the NH3-SCR reaction. Herein, the effects of different WO3 phases on the NH3-SCR performance of Ce-based catalysts are systematically investigated. The SCR activity of CeO2 is both evidently improved by the addition of W-h and W-m. It is noteworthy that CeO2–WO3-hexagonal (Ce–W-h) exhibits a more excellent NOx removal efficiency than CeO2–WO3-monoclinic (Ce–W-m) in the whole temperature window tested, and T50 and T90 of Ce–W-h are 51 and 111 °C lower than those of Ce–W-m, respectively. Importantly, compared with that of W-m, the special open structure of W-h not only facilitates NH3 adsorption and the diffusion of oxygen to improve the acidity and reducibility of the catalyst, but also is favorable for electron transfer between W-h and Ce to boost the interaction between W-h and Ce. Besides, the active plane (001) on W-h/Ce–W-h can provide abundant unsaturated W6+ and Bronsted acid sites. Accordingly, the Ce–W-h catalyst displays a more impressive NH3-SCR performance than Ce–W-m. W-h is a better choice to modify CeO2 to improve its SCR performance than W-m. This work provides a profound understanding of the intrinsic effect of the crystal phases of WO3 on NH3-SCR performance.

Low-temperature NH3–SCR activity and high-temperature hydrothermal stability have always been recognized as two great challenges in the current developments of candidate NH3–SCR catalysts for pract...

Low-temperature selective catalytic oxidation (SCO) is one of the important strategies used to remove the NH3 slip upstream of NH3 selective catalytic reduction (NH3-SCR). We have systematically studied the influence of the dispersity of active species, particle size and Pt0 content on the catalytic activity of ammonia oxidation with a Pt-based catalyst. Ascorbic acid was added to the modified Pt/SiO2–Al2O3 catalyst by the co-impregnation method for selective catalytic oxidation of ammonia (NH3-SCO), to explore the influence of different properties of the active components on the catalytic activity. It was found that addition of ascorbic acid changed the Pt0 content in the catalyst. Further studies found that increase in the Pt0 content could effectively promote activation of oxygen and facilitate more rapid conversion of O2 molecules to oxygen atoms. Thus, the dehydrogenation reaction of ammonia and oxygen atoms was promoted and proceeded at a lower temperature, improving the low-temperature activity of the NH3-SCO reaction. At the same time, it was shown that the Pt0 content in the system was the key factor affecting the NH3-SCO reaction, and this was confirmed by X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, H2 temperature-programmed reduction and in situ diffuse-reflectance infrared Fourier transform spectroscopy.

Hydrothermal stability of catalysts for selective catalytic reduction of NOx with NH3 (NH3-SCR) is essential to develop a promising candidate catalyst for removing NOx emitted from diesel engines. ...

Cu/SAPO-34/5 catalysts were prepared by a traditional hydrothermal/impregnation method to investigate the effect of SAPO-34/5 on deNOx performance over Cu/SAPO-34/5 (the proportion of SAPO-34/SAPO-...

Mechanical stretch commonly promotes craniofacial suture remodeling during interceptive orthodontics. The mechanical responses of osteoblasts in craniofacial sutures play a role in suture remodeling. Moreover, the extracellular matrix (ECM) produced by osteoblasts is crucial for the transduction of mechanical signals that promote cell differentiation. Therefore, we aimed to investigate the effect of mechanical stretch on cell viability and ECM-related gene-expression changes in human osteoblasts. Human calvarial osteoblasts (HCObs) were subjected to 2% deformation. Caspase activity, MTT, and cell viability assays were used to estimate osteoblast apoptosis, proliferation, and viability, respectively. Real-time RT-PCR (RT2 -PCR) arrays were used to assess expression of cytoskeletal-, apoptosis-, osteogenesis-, and ECM-related genes. We found that mechanical stretch significantly increased osteoblast viability and cell proliferation, and decreased the activities of caspases 3 and 7. Moreover, the expression of 18 genes related to osteoblast differentiation, apoptosis, and ECM remodeling changed by more than two-fold in a time-dependent manner. Therefore, mechanical stretch promotes HCOb viability and alters expression of genes that are closely related to suture remodeling under mechanical stretch.

As a promising candidate for NOx elimination from the emission of diesel engines, the enhancement effect of Ba on the hydrothermal stability of cordierite supported CuBa/BEA at 600 °C for 48 h was investigated by XRD, NH3-TPD, H2-TPR, XPS, EPR, TEM and in situ DRIFTS. Different properties and amounts of active species are significant factors contributing to the enhanced hydrothermal stability of CuBa/BEA-HT. CuBa/BEA-HT has more Cu2+/Cu+ redox-couples and stronger interactions than Cu/BEA-HT, indicating an excellent redox property of the active species in CuBa/BEA-HT. The better redox property of CuBa/BEA-HT produces more nitrates that easily participate in the NH3-SCR reaction, which enhances the low-temperature activity. Furthermore, as observed from EPR and H2-TPR, the appearance of more isolated Cu2+ species and fewer CuO species also contribute to the higher hydrothermal stability of CuBa/BEA-HT.

Objectives Both temporomandibular disorder (TMD) and knee osteoarthritis (KOA) are prevalent joint diseases; however, an association between them has not been reported. Therefore, this study investigated the prevalence of the specific symptoms and signs of TMDs (SSTs) in patients with KOA. Methods In total, 200 patients with KOA and 150 healthy individuals were recruited. The prevalence of specific SSTs in patients with mild or severe KOA was compared with the prevalence of specific SSTs in the control group and the results were analysed using a chi-square test. Logistic regression was used to adjust for potential confounders, such as gender and age. Results The prevalence of ‘impaired range of jaw movement (IRM)’ was 63.6% (n = 77) in the mild KOA group and 62.4% (n = 117) in the severe KOA group; the values for both KOA groups were significantly higher than that for the non-OA control group (34.7%, n = 144; P < 0.017). In addition, 54.7% of the patients with severe KOA reported ‘impaired temporomandibular joint (TMJ) function’, a value significantly higher than that of the control group (39.6%, P < 0.017). No significant differences between groups were found for other SSTs. Conclusions Patients with KOA might be more likely to experience SSTs, such as IRM and impaired TMJ function.

Sp7/Osterix as a zinc finger transcription factor is expressed specifically in osteoblasts. Embryonic lethality of Sp7 knockout mice, however, has prevented from examining the functions of Sp7 in osteoblast and bone formation in live animals. Here we used TALEN, a versatile genome-editing tool, to generate one zebrafish sp7 mutant line. Homozygous sp7−/− mutant zebrafish are able to survive to adulthood. Alizarin Red staining and Micro-CT analysis showed that sp7−/− larvae and adult fish fail to develop normal opercula, and display curved tail fins and severe craniofacial malformation, while Alcian Blue staining showed no obvious cartilage defects in sp7−/− fish. Quantitative RT-PCR showed that a number of osteoblast markers including spp1, phex, col1ala, and col1a1b are significantly down-regulated in sp7−/− fish. Furthermore, col10a1a, whose ortholog is the cartilage marker in mice, was shown to be a novel downstream gene of Sp7 as an osteoblast marker in zebrafish. Together, these results suggest that Sp7 is required for zebrafish bone development and zebrafish sp7 mutants provide animal models for investigating novel aspects of bone development.

The hydrothermal stability of NH3-SCR catalysts has always been an important factor affecting its industrial application. The collapse of BEA structure from the hydrolysis of Si-O-Al sites is the dominated reason of the hydrothermal deactivation over Cu/BEA. In this work, tetraethoxysilane (TEOS) was chose and deposited into the prepared Cu/BEA catalyst to protect these easily attacked sites. The loss of crystalline and specific surface area was affected effectively by Si-deposition into the Cu/BEA catalysts. Meanwhile, the more stable structure was closely related with the mitigated dealumination. To further optimal the improvement of Si-deposition method on the hydrothermal stability of Cu/BEA, the effect of Si on the surface structure-stability under different solvents (H2O, H2O/alcohol (volume ratio 1:1) and alcohol) were investigated systematically. H2O/alcohol mixture presented the superiority for the surface structure-stability of CuSi/BEA by adjusting the dispersion and hydrolysis of TOES, inhibiting the loss of the acid sites and more aggregated CuO better compared with other solvents. Moreover, the isolated Cu2+ were better preserved using H2O/alcohol mixture as solvent, which was good for activating NOx, and then further stabilized the deNOx performance of catalysts after the hydrothermal treatment. Besides, the advantage on isolated Cu2+ still played a key role on the low-temperature NH3-SCR reaction rather than acid sites after the hydrothermal treatment.

As a promising candidate for NOx elimination from the emission of diesel engines, the enhancement effect of Ba on the hydrothermal stability of cordierite supported CuBa/BEA at 600 °C for 48 h was investigated by XRD, NH3-TPD, H2-TPR, XPS, EPR, TEM and in situ DRIFTS. Different properties and amounts of active species are significant factors contributing to the enhanced hydrothermal stability of CuBa/BEA-HT. CuBa/BEA-HT has more Cu2+/Cu+ redox-couples and stronger interactions than Cu/BEA-HT, indicating an excellent redox property of the active species in CuBa/BEA-HT. The better redox property of CuBa/BEA-HT produces more nitrates that easily participate in the NH3-SCR reaction, which enhances the low-temperature activity. Furthermore, as observed from EPR and H2-TPR, the appearance of more isolated Cu2+ species and fewer CuO species also contribute to the higher hydrothermal stability of CuBa/BEA-HT.

Four different kinds of photovoltaic polymers were synthesized by controlling the intrachain noncovalent coulomb interactions through the incorporation of alkoxy- or alkylthio-substituted phenylene, 4,7-di(furan-2-yl)benzothiadiazole, and 4,7-di(thiophen-2-yl)benzothiadiazole as a building block. Fine modulation of the interplay of dipole–dipole, H-bond, and chalcogen–chalcogen interactions (O···S, O···H, S···S, S···F, etc.) along the polymeric backbone influenced the chain planarity, interchain organization, film morphology, and electrical and photovoltaic properties significantly. By replacing the alkoxy substituents with alkylthio groups, the torsional angle increased (136–168°) due to the absence of an O···S attractive coulomb interaction (and/or increased S···S steric hindrance), enhancing the amorphous nature with hindered interchain packing. The alkoxy-substituted polymers exhibited nanofibrillar structures, showing strong interlamellar scattering peaks up to (300) with tight face-on π–π stacking i...

A series of thienothiophene-benzotriazole-based semicrystalline copolymers, PTTBTz, PTTBTz-F, and PTTBTz-OR, were synthesized by considering chain linearity, planarity and inter-chain packing by virtue of non-covalent attractive interaction. Fluorine and alkoxy substituents were introduced to modulate the intra- and inter-chain coulombic interactions and crystalline ordering. The fluorine and alkoxy-substituted PTTBTz-F and PTTBTz-OR showed pronounced inter-chain packing with edge-on orientation confirmed by UV-vis absorption and X-ray diffraction measurements. The well-resolved diffraction patterns were obtained for PTTBTz-F and PTTBTz-OR, showing (100)∼(500) inter-lamellar scattering peaks (d-spacing, 17∼18 Å) in the out-of-plane direction and a π-π stacking peak (d-spacing, 3.5∼4.1 Å) in the in-plane direction. Organic field effect transistor (OFET) devices were fabricated with a bottom gate and top contact geometry. PTTBTz-F (μh = 4.49 × 10–2 cm2 V–1 s–1, on/off ratio = 1.13 × 107) and PTTBTz-OR (μh = 8.39 × 10–3 cm2 V–1 s–1, on/off ratio = 2.98 × 104) showed nearly 3 and 2 orders of magnitude higher hole mobility upon annealing at 305 and 260 °C, with compared to the unsubstituted PTTBTz.

We report a series of benzotriazole-based semicrystalline π-conjugated polymers with noncovalent conformational locks for applications in polymer field-effect transistors. The benzotriazole moiety is a versatile electron-deficient building block that offers two chemically functionalizable sites, 2(N) and 5, 6(C) positions, allowing easy modulation of the solution processability and electronic structures of the resulting polymers. Fluorine or alkoxy substituents were introduced to the benzotriazole unit to enhance the molecular ordering through intra- and intermolecular F···S, F···H–C, C–F···πF, or S···O attractive interactions. The fluorinated polymer (PTBTz-F) showed remarkably enhanced hole mobility (μh = 1.9 cm2/(V·s), on/off ratio = 8 × 107) upon thermal annealing at 305 °C, compared to the unsubstituted one (PTBTz) (μh = 7.0 × 10–3 cm2/(V·s), on/off ratio = 3 × 106). Alkoxy unit substitution (PTBTz-OR) also improved the carrier mobility up to 0.019 cm2/(V·s) with an on/off ratio of 4 × 105. Fluorine ...

To investigate the outcome of skeletal Class Ⅲ patients treated with Fränkel function regulator type Ⅲ (FR Ⅲ)in the early mixed and late mixed dentition.The samples consisted of 45 mild and moderate skeletal Class Ⅲ patients(26 males, 19 females; meanage, [7.9±1.3] years) treated with FR Ⅲ. According to Hellman's dental developmental stages, these samples were divided into early-treated group(n=24) and late-treated group(n=21). Lateral cephalograms were taken at the beginning and the end of treatment. Twenty-one measurements on hard and soft tissue were included.After treatment, SNA, ANB, NA-Apo, Wits, U1-SN, U1-NA, Overjet, UL-EP were significantly increased (1.0±1.9)°, (1.2±1.6)°, (2.6±4.2)°, (1.8±2.7) mm, (4.2±7.6)°, (2.6±7.5)°, (3.6±2.3) mm and (0.8±2.2) mm(P0.05). OP-SN and IMPA were significantly decreased (1.5±3.7)°and (1.4±4.2)°(P0.05). There were significant differences in SNA, ANB, UL-EP, IMPA, L1-NB between early-treated group and late-treated group(P0.05).FR Ⅲ was suitable for the treatment of mild and moderate skeletal Class Ⅲ patients. The result was better in the early-treated patients than in late-treated ones.

The common carp (Cyprinus carpio) as one of the most important aquaculture fishes produces over 3 million metric tones annually, approximately 10% the annual production of the all farmed freshwater fish worldwide. However, the tetraploidy genome and long generation-time of the common carp have made its breeding and genetic studies extremely difficult. Here, TALEN and CRISPR-Cas9, two versatile genome-editing tools, are employed to target common carp bone-related genes sp7, runx2, bmp2a, spp1, opg and muscle suppressor gene mstn. TALEN were shown to induce mutations in the target coding sites of sp7, runx2, spp1 and mstn. With CRISPR-Cas9, the two common carp sp7 genes, sp7a and sp7b, were mutated individually, all resulting in severe bone defects; while mstnba mutated fish have grown significantly more muscle cells. We also employed CRISPR-Cas9 to generate double mutant fish of sp7a;mstnba with high efficiencies in a single step. These results demonstrate that both TALEN and CRISPR-Cas9 are highly efficient tools for modifying the common carp genome and open avenues for facilitating common carp genetic studies and breeding.