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In this study, we report three electroactive carbazolyl polyimides (PIs) containing spiropyran, pyrene, and fluorescein fluorescent groups. The PIs exhibit red, blue, and green fluorescence emissio...

Given the unique properties of sewage sludge-derived carbonaceous materials (SC) and the correlation of SC with recycling sewage sludge in an efficiently safe way, there is significant attraction f...

A novel carbonate binder for utilization of CO2 was prepared with dehydration of waste hydrated cement paste. The effect of water-solid ratios (w/s) varying from 0.175 to 0.275 on carbonation properties of the carbonate binder was evaluated and its phase composition and microstructure before and after carbonation were characterized. The results showed that the compressive strength of carbonate binder exposed to a CO2-rich environment for 2 h maximized at 82.6MPa with w/s of 0.225 while the CO2 uptake was 27.2% which were on a par with that of carbonated pure dicalcium silicate (C2S) and carbonated steel slag. Analysis of phase composition and microstructure of the carbonate binder before and after carbonation revealed that the major phase beta C2S (β-C2S) in the dehydrated waste hydrated cement paste transformed into granular texture carbonation products (calcite and aragonite) with a size of less than 1μm. The carbonation products closely packed to form a large number of mesoporous which result in high compressive strength. The total CO2 uptake of carbonate binder in the whole preparation process was equal to that of the waste hydrated cement paste but it processed higher mechanical properties. It will provide a novel method to prepare high carbonation reactivity cementitious materials and improve the recycling rate of waste concrete which are benefit to utilization of CO2, energy conservation and environmental protection.

A series of electroactive polyamides (PAs) containing alkyl chains in backbone and triarylamine unit as the functional group were designed and synthesized by condensation polymerization of N-(2-amino-ethyl)-N-(4-carbazol-9-yl-phenyl)-ethane-1, 2-diamine with various dicarboxyl acids. The characterization confirms the successful synthesis. The thermal properties of the polymers investigated by thermo gravimetric analysis (TGA) indicate the polymers are hear-resisting. The main absorption peaks of PAs appear at λmax = 283–296 nm and strong photoluminescence (PL) peaks at 363–404 nm exhibit in the NMP. Electrochromic (EC) characteristics of the PAs films reveal excellent stability together with multistep EC behaviors, which change from the almost colorless neutral form to the green, then dark green oxidized forms at applied potentials. The resistance memory with good electrical bistable resistive switching characteristics, which possesses low threshold voltage (VSET of −1.6 V and VRESET of 4.2 V). Conclusionally, the PAs can be used as hole transporting, electrochromic, electrofluor, and a nonvolatile memory materials.

A multifunctional integrated platform based on conjugated oligomers containing novel triarylamine (TAA) and fluorene units with responding to voltage, light and explosives stimuli and performing for sensors, detectors, memory media and high contrast displays was designed, and the stimuli-responsive mechanisms were studied. These oligomers show excellent thermal stability with no significant weight loss below 350 °C in nitrogen atmosphere. During the electrochemical reoxidation process, the oligomer films exhibit two pairs of obvious redox peaks with the strong color changes from yellowish of neutral state to green and blue of oxidized state, and remain good continuous cyclic stability over 500s with a cycle time of 10s. The electrofluorescent properties of the oligomers also can be tuned by electrochemistry redox, exhibiting high contrast. Meanwhile, non-volatile rewritable flash memory devices were produced with the sandwich structure ITO/oligomer/Al, which could gain the ON/OFF current ratio as high as about 104 at low threshold voltage of 1.2 V.

Background: The third-generation genome editing system CRISPR/Cas had shown strong application prospects in crop genetic improvement. However, this technology largely depends on genetic transformation. Public concerns on GMO (genetically modified organisms) safety, as well as related regulations, have restricted the application. Therefore, establishing DNA-free transfection system is important to promote CRISPR/Cas genome editing in agriculture.Results：In this paper, cell penetrating peptides fusion protein (CPP-mCherry) was found to be effective on DNA-free transfection. DNA sequences of nine tandem arginine (R9), one cysteine (cys), reporter mCherry and histidine label were sequentially constructed into pET 45B+ expression vector and transformed into Escherichia coli BL21(DE3) strain. CPP-mCherry fusion protein can be induced by 1mM IPTG for at least 1 hour in 28 °C. CPP-mCherry fusion protein can be obtained by 200W ultrasonication, then purified by Ni column and MWCO dialysis. The Arabidopsis thaliana root tips and leaves, as well as Chinese cabbage microspores and 3-week-old microspore embryo can be used as transfected recipient. Concentration can be selected between 10-100μg/ml and incubated overnight at room temperature. R9-cys-mCherry protein can be translocated into the nucleus of microspore. The transfection efficiency of root tips reached 100% and of microspore and MDE was 8.13% and 94.79%, respectively. Conclusions: Here, a CPP mediated DNA-free transfection system was built in dicots. These results lay a technical foundation of DNA-free genome editing.

Genome editing technology based on the clustered regularly interspaced short palindromic repeats/Cas system is an important achievement of molecular biology. Nevertheless, public concerns regarding genetically modified organisms and regulatory restrictions have limited the use of this technology. Cell-penetrating peptides (CPPs) are protein transduction domains, usually less than dozens of amino acids, which have the ability to take cargo and penetrate the cell membrane of recipient cells. CPPs have only minor cytotoxicity and are ideal transfection tools for DNA-free transfection and genome editing in plants. In this review, we discuss the classifications and translocation mechanisms of CPPs, as well as the brief history of CPPs mediated DNA-free genome editing

Background Stimulus-responsive degradable mesoporous organosilica nanoparticles (MONs) have shown great promise as drug carriers via enhancing the efficiency of drug delivery and accelerating the degradation of nanocarriers. However, it remains a great challenge to develop novel light-enabled spatial and temporal degradable MONs with both superior responsiveness for efficient anti-cancer drug delivery and safe exocytosis. Results We report a novel photo-responsive degradable hollow mesoporous organosilica nanoplatform (HMONs@GOQD). The platform is based on organosilica nanoparticles (HMONs) containing singlet oxygen (1O2)-responsive bridged organoalkoxysilanes and wrapped graphene oxide quantum dots (GOQDs). The unique hollow mesoporous structure of the HMONs guarantees an excellent drug loading and release profile. During light irradiation, 1O2 produced by the GOQDs leads to the degradation of the organosilica nanoparticles, resulting in enhanced local drug release. Conclusions We carried out in vitro and in vivo experiments using DOX as a model drug; DOX-HMONs@GOQDs exhibited high biocompatibility, accelerated degradation, and superior therapeutic efficacy during light irradiation, indicating a promising platform for clinical cancer therapy.

A series of polyimides (PIs) were prepared by polycondensation of a diamine monomer with five anhydrides (1,2,4,5-benzenetetracarboxylic anhydride (BTA), 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTD), 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BTD), 4-[(1,3-dihydro-1,3-dioxo-5-isobenzofuranyl)oxy]-1,3-isobenzofurandione (DDII), and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BPTD)), which have anodic electrochromic (EC) properties. These PIs not only show good solubility and thermal stability, but also demonstrate stable electrochemical oxidation behavior and good EC properties, and the highest retained electroactivity reaches 99% after 600 cycles. In addition, the series of PIs exhibit excellent electrofluorescencechromic (EFC) properties. Therefore, the novel materials will contribute to the application of EC or EFC displays in the future.

In this study, steel/aluminum clad tubes with metallic bond were fabricated by spin bonding process, and the effects of spinning process parameters and post-annealing treatment on bond strength of 1020St/AA3A21 interface were investigated. The results show that firm metallic bond was formed at elevated temperatures. Bond strength increased with the increasing of thickness reduction, while feed rate exhibited insignificant influence on the bond strength. The maximum bond strength was achieved under the spinning temperature of 200 °C and thickness reduction of 50%. Annealing treatment at 400 to 500 °C for 1 h reduced the bond strength due to the softening of Al base metal. The Fe/Al intermetallic compounds were formed when the annealing temperature increased up to 550 °C, leading to the failure of interface bond. Large residual stresses caused the bending deformation of clad tubes, which could be released by annealing at 300 °C for 1 h and cooling down at the speed of 30 °C/h without penalty of bond strength. Spin bonding exhibited particular advantage in producing clad tube of dissimilar metals with high bonding strength.

The joint surface of the 1060 aluminum and AZ31 magnesium alloy was prepared through friction stir lap welding (FSLW) under different welding process parameters. The joint surface was characterized three-dimensionally using a three-dimensional (3D) optical profiler, and the coordinate data were obtained. The fractal dimension of the joint surface was calculated by the box-width transformation method using a MATLAB program. Furthermore, the influence of the welding process parameters on the fractal dimension of the joint surface was studied. The response surface model was established based on the principle of central composite design (CCD), and analysis of variance (ANOVA) was carried out to test the accuracy of the response surface. The results showed that the joint surface morphology had fractal characteristics, and the fractal dimension could be used as an index to characterize the quality of the joint surface. The change of the welding process parameters had a great impact on the fractal dimension of the joint surface, the interaction between the parameters was small, and the fitting accuracy of the response surface model was high. The fractal dimension of the joint surface decreased with the increase in the welding and rotational speeds and the effect of the rotational speed was more significant.

Polymeric carbon nitride (C3N4) with atomic thick layers has displayed ultrashort carrier transfer and ion/molecule migration path for enhancement of photocatalytic performance. However, rational modulation towards electron configurations of ultra-thin C3N4 nanosheets is still a challenge, because the existing exfoliation strategies suffer from uncontrollable atom-defects and edge functional groups, leading to poor solar-to-fuel conversion efficiency. Herein, a post-redox method is developed to form atomic thick C3N4 nanosheets with optimized electron configurations through liquid exfoliation and C-reduction. The as-prepared carbon-reduced atomic thick C3N4 (CRed-AT-C3N4) expose more active sites, greatly enhance charge carrier mobility and distinctly reduce the optical band gap, thus leading to a remarkably improved photocatalytic hydrogen evolution rate of 246.2 μmol h−1 under visible light irradiation (λ > 420 nm), which is 17-fold higher than that of the pristine counterpart. The apparent quantum efficiency reaches 18.52 % at 420 nm and surpasses most of existing C3N4-based photocatalysts.

The purpose of this research is to use a simple method to prepare magnetic modified corncobs (MCBs) with good adsorption performances for Congo Red (CR). The adsorption was analyzed by Fourier transform infrared spectroscopy and x-ray diffraction. The maximal adsorption capacity of the MCB for CR was 198.2 mg/g and about 5.5-fold for unmodified corncob. Potassium ion was more positive effect onto adsorption than sodium ion. The dye uptake process obeyed the pseudo-second-order kinetic expression. The best-fitted data were obtained with the Langmuir model. The as-prepared magnetic modified sorbent had a potential in the dyeing industry wastewater treatment.

This paper aims to evaluate the effects of ultraviolet-B radiation (UVBR) on Gracilaria lemaneiformis, a commercial red macroalga and an important source of agar. To study the in-vitro effect of UVBR on G. lemaneiformis, this plant was cultivated and exposed to photosynthetically active radiation (PAR) at 40 μmol photons/(m2 ·s) and enhanced UVBR (0, 0.36, 0.72, 1.08, 1.44, and 1.80 kJ/(m2 ·d)) for 13 days. The samples were processed for histochemical analysis, and the growth rate, photosynthetic pigment contents, photosynthetic performance, reactive oxygen species levels, membrane permeability, malonyl dialdehyde contents and antioxidant capacity of G. lemaneiformis were investigated. After 13 days of exposure to PAR+UVBR, G. lemaneiformis showed photodamage and photoinhibition of photosynthetic pigments (chlorophyll a and phycoerythrin), leading to a decreased photosynthetic efficiency. Further, there was a corresponding decrease in the relative growth rates and depigmentation and partial necrosis of the apical segments were noted after exposure to PAR+UVBR. Additionally, UVBR induced excess production of superoxide radicals and hydrogen peroxide, eliciting a marked cellular membrane damage and antioxidative response.

Four novel materials containing isoindigo derivatives were synthesized via Stille coupling reaction. These polymers not only have excellent electrochromic properties (the highest electrochromic efficiency reaches 195 cm2 C−1), but also have low charge transfer resistance (Rct). The range of switching threshold is from −1.7 V to −4.0 V and the current ratio of the device beyond 10−5 for memory device. Moreover, the polymers can also be used as explosive detector. A sharp drop in the fluorescence intensity of the polymer appeared when trinitrotoluene (TNT) or 2, 4, 6-trinitrophenol (TNP) was added.

Osmopriming with PEG has potential to improve seed germination, seedling emergence, and establishment, especially under stress conditions. This research investigated germination performance, seedling establishment, and effects of osmopriming with PEG on physiology in sorghum seedlings and their association with post-priming stress tolerance under various soil moisture stress conditions. Results showed that seed priming increased the environmental range suitable for sorghum germination and has potential to provide more uniform and synchronous emergence. Physiologically, seed priming strengthened the antioxidant activities of APX, CAT, POD, and SOD, as well as compatible solutes including free amino acid, reducing sugar, proline, soluble sugar, and soluble protein contents. As a result, seed priming reduced lipid peroxidation and stabilized the cell membrane, resulting in increased stress tolerance under drought or excessive soil moisture environments. Overall, results suggested that seed priming with PEG was effective in improving seed germination and seedling establishment of sorghum under adverse soil moisture conditions. Osmopriming effectively strengthened the antioxidant system and increased osmotic adjustment, likely resulting in increased stress tolerance.

This paper has researched on the adsorption of Cr(VI) in water using peanut shell. The dependence on pH and Cr(VI) concentration of the adsorption was studied. Batch experiments results showed that the adsorptive capacity of peanut shell was 13.39 mg/g of adsorbent. The Langmuir and Freundlich models were used to describe the adsorption equilibrium of Cr(VI) on peanut shell and the adsorption followed the Langmuir isotherm. The Langmuir and Freundlich constants for adsorption of Cr(VI) on peanut shell were determined.

This paper has researched on the adsorption of Ni in water using Laminaria japonica and Undaria pinnatifida. The dependence on pH and nickel concentration of the adsorption was studied. Batch experiments results showed that the adsorptive capacity of Laminaria japonica and Undaria pinnatifida was 2.933mg/g and 0.985 mg/g of adsorbent. The Langmuir model was used to describe the adsorption equilibrium of nickel on Laminaria japonica and Undaria pinnatifida. The Langmuir constants for adsorption of Ni on Laminaria japonica and Undaria pinnatifida were determined.