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Intervertebral disc degeneration (IDD) is a very common disease worldwide and the leading cause of low back pain. Long non-coding RNAs (lncRNAs) are novel players in IDD and present multiple functions. Our work explored the role of lncRNA HCG18 in regulating extracellular matrix (ECM) degradation in nucleus pulposus cells (NPCs) during IDD.NPCs were subjected to IL-1β to induce degenerative model of NPCs. Cell viability was assessed using CCK-8 assay. The mRNA and protein expressions were examined by qRT-PCR and western blot. The location of HCG18 was determined by nucleo-cytoplasmic separation experiment. The binding relationships between HCG18, miR-4306 and EPAS1 were verified by dual luciferase reporter gene assay and/or RIP assay.The results displayed that HCG18 was highly expressed in IL-1β-induced degenerated NPCs, which was associated with reduced Collagen II and Aggrecan expressions and increased MMP-13 and ADAMTS-4 expressions. HCG18 knockdown could remarkably inhibit ECM degradation in IL-1β-induced degenerated NPCs, while HCG18 overexpression presented the opposite effect. Our molecular study further revealed that HCG18 could sponge miR-4306. And HCG18 knockdown could suppress ECM degradation in degenerated NPCs by elevating miR-4306 expression. In addition, EPAS1 was identified as the direct target of miR-4306. As expected, miR-4306 overexpression inhibited ECM degradation in degenerated NPCs by downregulating EPAS1.HCG18 promoted ECM degradation in degenerated NPCs via regulation of the miR-4306/EPAS1 axis.

Brønsted acid sites rather than Lewis acid sites play an important role in controlling the product selectivity in the hydrodeoxygenation of n-C11H23COOCH3 over supported Ru catalysts.

A new kind of poly(urea-imine) thermosets with high mechanical performances and self-healing, recyclable and degradable characteristics was synthesized with CO2 as one building block.

Drought stress adversely impacts crop development and yield. Maize frequently encounters drought stress during its life cycle. Improvement of drought tolerance is a priority of maize breeding programs. Here, we identified a novel transcription factor encoding gene, APETALA2 (AP2)/Ethylene response factor (ERF), which is tightly associated with drought tolerance in maize seedlings. ZmERF21 is mainly expressed in the root and leaf and it can be highly induced by polyethylene glycol treatment. Genetic analysis showed that the zmerf21 mutant plants displayed a reduced drought tolerance phenotype, accompanied by phenotypical and physiological changes that are commonly observed in drought conditions. Overexpression of ZmERF21 in maize significantly increased the chlorophyll content and activities of antioxidant enzymes under drought conditions. RNA-Seq and DNA affinity purification sequencing analysis further revealed that ZmERF21 may directly regulate the expression of genes related to hormone (ethylene, abscisic acid) and Ca signaling as well as other stress-response genes through binding to the promoters of potential target genes. Our results thereby provided molecular evidence of ZmERF21 is involved in the drought stress response of maize.

A series of silver sulfide composites were prepared via the hydrothermal method with l-cysteine and AgNO3 in water at a range of l-cysteine/AgNO3 molar ratio of 0.5–8. The prepared Ag/AgxS material...

The selective hydrodeoxygenation of lignin-derived guaiacol to value-added products, especially phenol, under relatively mild reaction conditions remains an important challenge. A Cl-modified Ru/TiO₂ catalyst exhibited higher phenol selectivity compared with an unmodified one in the conversion of guaiacol in 1,4-dioxane at 240 °C and 1 MPa H₂. Unlike Ru/TiO₂, the modified catalyst exhibited a modest activity of demethoxylation producing phenol but an inferior ability of hydrogenation of its aromatic ring, resulting in much slower consumption of phenol. The Cl species were likely localized at the metal–support interface and on the surface of metal particles, and these modified both Ru and Ti species electronically. It is presumed that electron-enriched Ru inhibits the ring hydrogenation reaction, and the defects on the TiO₂ surface promote the deoxygenation reaction.

Perovskite solar cells (PSCs) have shown great potential as a next generation photovoltaic candidate due to the low cost and high efficiency of the devices. However, the ionic and polycrystalline natures of perovskite films lead to high defect densities deteriorating device stability and efficiency, which impedes the practical applications of PSCs. Here, we introduce a novel passivation concept which employs a functional amorphous 5-sulfosalicylic acid (5-SSA)/PbI2 layer with COO− and SO3− groups to suppress defects of under-coordinated Pb2+ ions and iodide vacancies at grain boundaries/surfaces of MAPbI3 films. Furthermore, we find that the amorphous phase can lead to the enlargement of grain size, passivation of defects and suppression of ion migration in the as-deposited perovskite films. Consequently, the 5-SSA/PbI2-modified MAPbI3 devices exhibit efficiencies up to 21.47% and 21.02% on rigid and flexible substrates, respectively. Moreover, the shelf life (3000 h in air with low humidity) and thermal stability (500 h at 60 °C in N2) have been significantly improved. This work provides a promising strategy for overcoming the inherent instability of perovskite films in optoelectronic applications.

The fabrication of self-healing and recyclable CO2-based polymeric materials meets the requirement of sustainable development. By introducing reversible hydrogen bonds and heat-responsive Diels–Alder bonds, a new, environmentally friendly, self-healing and recyclable polyurethane-urea Diels–Alder adduct (PUUa-DA) was successfully synthesized using CO2 and furfuryl amine as renewable feedstocks. PUUa-DA was semi-crystalline and exhibited high thermal stability, 5% weight loss temperature being above 220 °C. Moreover, PUUa-DA with a cross-linked structure showed a tensile stress of 18.5 MPa, a modulus of 151 MPa and an elongation at break of 136%. The dynamic Diels–Alder bonds and hydrogen bonds provide the self-healing response and contribute to 94% recovery of the tensile strength upon heating. Therefore, PUUa-DA will have potential applications as a functional material in a wide range of practical fields. The synthesis of PUUa-DA using CO2 and bio-based furfuryl amine will be of importance in green and sustainable chemistry.

The transformation of CO2 can alleviate environmental problems and promote sustainable development. We prepared polyureas (PUas) from CO2 and diamines via an isocyanate-free route. PUas synthesized...

To convert CO2 into valuable polymers is of great significance from the viewpoints of environmental and sustainable development, as polymers are among the most widely produced chemicals in the worl...

A versatile gold(I)-catalyzed cross-coupling reaction of 3-diazooxindoles with diazoesters has been presented, affording (E)-3-alkylideneoxindoles stereoselectively. Density functional theory calculations rationalized the chemo- and stereoselectivity of the reaction, which was in good agreement with experimental observations. In addition, (E)-3-alkylideneoxindoles were converted into their (Z)-isomers under UV-irradiation facilely, indicating the great advantage of this approach in stereoselective synthesis of both (E)- and (Z)-3-alkylideneoxindoles.

A series of Pd-ZnO/TiO2, Pd/TiO2, and Pd/ZnO catalysts were synthesized and investigated for N-methylation of N-methylaniline (MA) to N,N-dimethylaniline (DMA) with CO2 and H2. A high performance w...

The transformation of γ-valerolactone (GVL) into 1,4-pentanediol (1,4-PDO) and 2-methyltetra-hydrofuran (2-MTHF) in the presence of H2, one of the useful biomass conversion and utilization processes, was investigated with monometallic Cu/Al2O3 and bimetallic ZnCu/Al2O3 catalysts. A 10 wt% Cu-loaded monometallic catalyst produced 1,4-PDO and 2-MTHF in comparable quantities at a medium conversion (∼50%). When Zn was added in a range of Zn/Cu molar ratios of up to 2, in contrast, the catalysts yielded 1,4-PDO in a high selectivity of about 97% at low and high conversion levels. In addition, the 1,4-PDO selectivity over the ZnCu/Al2O3 catalysts remained almost unchanged during recycled runs. That is, the addition of Zn to Cu/Al2O3 switched the product selectivity and improved the catalyst stability and reusability. Furthermore, the physicochemical properties of the catalysts were characterized by several methods including XRD, TEM, TPR, XPS, FTIR of adsorbed pyridine, and so on. On the basis of those results, the relationships between the catalytic performance (activity, selectivity, and reusability) and the catalyst structural features were discussed.

The hydrodeoxygenation of a model compound, ethyl stearate, of biomass-derived resources into long chain alkanes was investigated with Re-modified Ru/TiO2 catalysts. A monometallic Ru(1)/TiO2 catalyst, in which Ru was loaded in 1 wt%, gave a selectivity of >95% to the long chain alkanes of n-octadecane and n-heptadecane at almost 100% conversion at 220 °C, while another monometallic Re(10)/TiO2 catalyst was less active in spite of its higher metal loading (10 wt%). It is interesting that the addition of less active Re species to Ru(1)/TiO2 not only enhanced the rate of hydrodeoxygenation and increased the ratio of n-octadecane/n-heptadecane, while the high total selectivity towards alkanes remained unchanged. The alkane ratio depended on the content of Re added, increasing significantly from 0.5 for Ru(1)/TiO2 to 3.2 for Ru(1)Re(10)/TiO2. The impacts of Re addition on the catalytic performance of Ru/TiO2 were discussed on the basis of physicochemical properties characterized for Re-modified and unmodified Ru/TiO2 catalysts. It is suggested that the improved hydrodeoxygenation activity of Re-modified catalysts depends on the presence of Lewis acid sites, and the weak acid sites are important for determining catalytic selectivity. In addition, reaction pathways in the hydrodeoxygenation of ethyl stearate to n-octadecane and n-heptadecane were examined by control reactions with possible intermediates such as 1-octadecanol and stearic acid. The Re-modified Ru/TiO2 catalysts were shown to be recyclable during repeated runs when the same mole ratio of catalyst to substrate was used.

The transformation of CO2 into polymeric materials is an important and hot research topic from the viewpoint of renewable resources and environmental effects. Herein, a series of polyureas have been synthesized by polycondensation from CO2 with diamines of 1,12-diaminododecane (DAD) and/or 4,7,10-trioxa-1,13-tridecanediamine (TTD). The properties of polyureas synthesized were characterized by FTIR, 1H NMR, 13C NMR, XRD, DSC, TGA, and DMA. The polyureas synthesized from CO2 with a mixture of diamines presented high performances compared to those of polyureas synthesized from CO2 with a single diamine. The thermal and mechanical properties were improved largely by the variation in the crystallization and the chain flexibility depending on the changes in the density and/or intensity of hydrogen bonds. With increasing amounts of TTD from 0 to 100% in weight, the melting (Tm), crystallization (Tc), and glass transition (Tg) temperatures decreased from 207 to 116 °C, from 181 to 54 °C, and from 66 to -34 °C, respectively. When the TTD content was increased from 0 to 50 wt %, the Young's modulus decreased from 1170 to 406 MPa, and the tensile strength decreased from 53.3 to 42.9 MPa. However, the elongation at break increased from 13 to 330%. Furthermore, the chain length of aliphatic diamines and polyetheramines had a significant effect on the mechanical properties. The initial decomposition temperature (Td,5%) is >295 °C, about 110 °C higher than the Tm (116-207 °C), which is advantageous for the postprocessing. The mechanical properties of the polyureas synthesized herein are superior to those of polycarbonate and polyamide 6. Thus, polyureas synthesized from the renewable and cheap resources, CO2 and diamines, will find wide potential applications in the field of polymeric materials.

A Pt/TiH2 catalyst having hydrogen storage and release capability was investigated for selective hydrogenation of trans-cinnamaldehyde (CAL) to cinnamyl alcohol (COL) with gaseous dihydrogen. The c...

Photodetectors (PDs) are the building block of various imaging and sensing applications. However, commercially available PDs based on crystalline inorganic semiconductors cannot meet the requirements of emerging wearable/implantable applications due to their rigidity and fragility, which creates the need for flexible devices. Here, a high-performance flexible PD is presented by gating an organic electrochemical transistor (OECT) with a perovskite solar cell. Due to the ultrahigh transconductance of the OECT, the device demonstrates a high gain of ≈10

To establish the hydro-pneumatic suspension model more accurately and better analyze the influence of heavy vehicle hydro-pneumatic suspension system on road friendliness, the fractional order theory is applied to modeling, and the mathematical model and dynamics model of dual-chamber hydro-pneumatic suspension with fractional order are established by using Matlab/Simulink, and the fractional order differential term of the suspension system is calculated according to the improved Oustaloup filter. The effect of fractional order on suspension stiffness, damping and output forces is also investigated. The optimal fractional order is determined to be 0.9 for the design of a combined suspension performance index function. The vibration law of increasing amplitude and error of fractional-order is obtained through simulation, and the model with fractional-order is described more accurately. A sliding film variable structure controller was established for control. The simulation results were analyzed by means of theoretical road damage factors and dynamic load factors. The results show that the suspension system model with fractional order terms can effectively reduce the dynamic tire load and improve the suspension smoothness and road friendliness.

A versatile gold(I)-catalyzed cross-coupling reaction of 3-diazooxindoles with diazoesters has been presented, affording (

The selectivity of 3-nitrostyrene (NS) hydrogenation over 0.5 wt-% Pt catalysts supported on carbon materials can be switched simply by changing reduction temperature. When the reduction temperature was 150 °C, 1-ethyl-3-nitrobenzene (ENB) was mainly produced in a selectivity of 93% at a conversion of 95% (at 100 °C). When the reduction was conducted at a higher temperature of 450 °C, in contrast, the main product was switched to 3-aminostyrene (AS) in a selectivity of 96% at a conversion of 91%. That is, the Pt/C catalysts reduced at low and high temperatures could preferentially catalyze the hydrogenation of vinyl and nitro groups of NS, respectively. This switching of the product selectivity may be ascribed to actions of surface oxygen-containing functional groups and surface hetero P species. The quantity and nature of these surface species were examined in detail by a few different methods. For the low-temperature reduced catalyst, surface acidic groups present close to Pt nanoparticles (∼2 nm) would interact with the nitro group of a NS molecule and make its vinyl group more likely to interact with the surface active metal species of Pt nanoparticles; this facilitates the hydrogenation of the latter and produces ENB selectively. For the high-temperature reduced catalyst, however, P species would interact with Pt and form Pt-PO x complex, on which a NS molecule is likely to be adsorbed with its nitro group, facilitating the selective production of AS via its hydrogenation. It is demonstrated that surface functional groups and surface hetero atoms (like P), in addition to main active metal species (like Pt), should have direct actions in the catalysis for such a catalyst that exposes a larger quantity of surface functional groups and/or hetero atoms compared to the number of supported metal nanoparticles .

The combination of CO2 and H2O as green solvents has been used extensively in chemical reaction and attracted much attention. The conversion and/or selectivity could be improved in the presence of both CO2 and H2O. In this paper, the promotion effects of CO2 and H2O on the selective hydrogenation reactions are shortly reviewed.

ZnPd bimetallic nanoparticles supported on the Al-doped ZnO support showed efficient catalytic performance for glycerol hydrogenolysis to 1,2-propanediol (1,2-PDO). The Al species in the ZnPd/ZnO-3Al catalyst were highly related to the reaction activity of the catalysts. It was confirmed that the AlA(IV) species in the ZnPd/ZnO-3Al catalyst determined the reduction of ZnO, the size of ZnPd, oxygen vacancy density, and the reaction activity. Calcination temperature had significant influences on the distribution and migration of Al(IV) in ZnO lattice, and hence affected the reaction activity.

Solvent effects in the selective hydrogenation of an α,β-unsaturated aldehyde of cinnamaldehyde (CAL) were investigated under gas–liquid–solid reaction conditions. A conventional 5 wt% Pd/C catalyst and twelve organic solvents were used, including apolar solvents (three) and protic (two) and aprotic (seven) polar ones. The total rate of CAL hydrogenation strongly depended on the solvents used. The relationship between the rate of CAL hydrogenation observed and a few different solvent parameters was examined. The main product was hydrocinnamaldehyde (HCAL) with a selectivity of 80% or higher in most of the solvents examined except for pyridine and 4-methylpyridine. In these two solvents, the CAL hydrogenation was slow and the main product was changed to cinnamyl alcohol (COL) with a selectivity of about 60%. The addition of a small volume of pyridine to other solvents such as 2-propanol and tetrahydrofuran could change the rate of hydrogenation and switch the main product from HCAL to COL. Possible interactions among the solvents, CAL substrate, and Pd/C catalyst were examined by FTIR (attenuated total reflection (ATR-) and diffuse reflectance modes (DR-)) and TPD to discuss the solvent effects observed in the Pd-catalyzed heterogeneous CAL hydrogenation.

Sn-Pb mixed perovskites with bandgaps in the range of 1.1-1.4 eV are ideal candidates for single-junction solar cells to approach the Shockley-Queisser limit. However, the efficiency and stability of Sn-Pb mixed perovskite solar cells (PSC) still lag far behind those of Pb-based counterparts due to the easy oxidation of Sn2+ . Here, a reducing agent 4-hydrazinobenzoic acid (HBA) is introduced as an additive along with SnF2 to suppress the oxidation of Sn2+ . Meanwhile, vertical Pb/Sn compositional gradient is formed spontaneously after an antisolvent treatment due to different solubility and crystallization kinetics of Sn and Pb-based perovskites and can be finely tuned by controlling the antisolvent temperature. Because the band structure of a perovskite is dependent on its composition, graded vertical heterojunctions are constructed in the perovskite films with compositional gradient, which can enhance photocarrier separation and suppress carrier recombination in resultant PSCs. Under optimal fabrication conditions, the Sn-Pb mixed PSCs show power conversion efficiency up to 22% along with excellent stability during light soaking. This article is protected by copyright. All rights reserved.