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A novel supra-amphiphilic metallogelator [Cu12](OTf)2 having functional dibenzo-24-Crown-8 as hydrophilic part and complexed Cu2+/terpyridine as hydrophobic part was prepared from an amphiphilic precursor. The supra-amphiphilic metallogelator was found to be able to gel in toluene/CH3CN or THF/CH3CN. The self-assembly mechanism of [Cu12](OTf)2 into supramolecular gel was extensively studied by FT-IR, UV-Vis, fluorescence, PXRD spectroscopic techniques, and theoretical calculations, revealing that the intermolecular π-π interaction plays a vital role in the gel formation. Due to the presence of dibenzo-24-Crown-8 and coordinating terpyridine motif within the supra-amphiphilic metallogelator, the reversible gel-sol transition can be induced by several stimulus, including temperature, pH, mechanical force, and metal ion/competitive host molecule, making this supramolecular gel highly adaptive to the external environment. The work reported here offers prospects for designing more metal-based supra-amphiphilic self-assembly building blocks by integrating the functions from both ligands and metal ions, opening new avenues for preparing multiple stimuli-responsive and adaptive materials.

Nanogels have been widely prepared and characterized in recent years due to their unique advantages. Here, an effective, original, and facile method of emulsion-free photopolymerization at 532 nm without surfactant was developed to prepare nanogels based on poly(ethylene glycol) diacrylate (PEGDA). The 532 nm continuous laser with symmetrical energy distribution like a three-dimensional shape of a straw hat was used to control the reaction region. The self-emulsification of PEGDA in water was studied and PEGDA micelles were directly cross-linked by controlling the laser energy. The number of micelles participating in the microreaction region and the double bond crosslinking between micellar aggregates and inside micelles were reasonably regulated. The size of the nanogels could be effectively modulated by controlling reaction parameters including laser power, monomer concentration, initiator concentration, and reaction time. Finally, ultrasmall nanogels with around 30 nm in size were prepared by balancing double bond crosslinking between micellar aggregates and inside micelles.

Veterinary drugs have been widely used in the food industry. Their residues in food products need to be tightly regulated to ensure food safety. In particular, some veterinary drugs are still used illegally, although they have already been banned. Nanomaterials are playing an increasingly important role in analytical chemistry due to their unique properties. Compared to traditional organic dyes and colloidal gold nanoparticle labels, fluorescent nanomaterials appear particularly attractive for the detection of veterinary drug residues. This review summarizes recent advancements of fluorescent biosensors using nanomaterials for the detection of veterinary drug residues in foods. The useful properties of each type of fluorescent nanomaterial are first discussed such as large Stokes shifts, long emission lifetime, and high quantum yields, which are useful for detection in food-related sample matrix. The following target recognition molecules are then reviewed individually including antibodies, aptamers, molecularly imprinted polymers, and metal ion coordination based ligands. Representative bioconjugation and assay methods are discussed for each recognition mechanism. Finally, a few future research directions are outlined in the last section of this review.

Unlike adult mammalian heart, zebrafish heart has a remarkable capacity to regenerate after injury. Previous study has shown Notch signaling activation in the endocardium is essential for regeneration of the myocardium and this activation is mediated by hemodynamic alteration after injury, however, the molecular mechanism has not been fully explored. In this study we demonstrated that blood flow change could be perceived and transmitted in a primary cilia dependent manner to control the hemodynamic responsive klf2 gene expression and subsequent activation of Notch signaling in the endocardium. First we showed that both homologues of human gene KLF2 in zebrafish, klf2a and klf2b, could respond to hemodynamic alteration and both were required for Notch signaling activation and heart regeneration. Further experiments indicated that the upregulation of klf2 gene expression was mediated by endocardial primary cilia. Overall, our findings reveal a novel aspect of mechanical shear stress signal in activating Notch pathway and regulating cardiac regeneration.

Nanogel is an important kind of biomaterials applied for wound dressings, drug delivery, medical diagnostics and biosensors. The properties of nanogels closely depend on the density of the crosslinking network. In this study, the role of triethanolamine (TEOA) in the effect on the crosslinking degree of nanogels based on poly(ethylene glycol) diacrylate (PEGDA) was investigated and illustrated. The effect of TEOA on the process of photopolymerization at 532 nm and properties of the nanogels was systematically investigated by using UV-vis spectroscopy, FT-IR spectroscopy, 1 H NMR, DLS, SEM, AFM and DSC. In brief, the double-bond conversion of photopolymerization and the crosslinking degree of nanogels can be effectively regulated by TEOA.

On the basis of the host–guest molecular recognition interaction between β-cyclodextrin and azobenzene, two kinds of supramolecular self-assemblies (Py-CD⊃Azo-C and Py-CD⊃Azo-C3) were constructed. Owing to the azo group on the guest molecule, supramolecular vesicles could reversibly realize disassembly and reassembly under irradiation with UV and visible light. Because of the existence of terpyridine groups on the surfaces of supramolecular vesicles, addition of metal ions triggers the vesicle–vesicle self-assembly from the nanoscale to the microscale.

Unlike mammals, zebrafish can regenerate injured hearts even in the adult stage. Cardiac regeneration requires the coordination of cardiomyocyte (CM) proliferation and migration. The TGF-β/Smad3 signaling pathway has been implicated in cardiac regeneration, but the molecular mechanisms by which this pathway regulates CM proliferation and migration have not been fully illustrated. Here, we investigated the function of TGF-β/Smad3 signaling in a zebrafish model of ventricular ablation. Multiple components of this pathway were upregulated/activated after injury. Utilizing a specific inhibitor of Smad3, we detected an increased ratio of unrecovered hearts. Transcriptomic analysis suggested that the TGF-β/Smad3 signaling pathway could affect CM proliferation and migration. Further analysis demonstrated that the CM cell cycle was disrupted and the epithelial–mesenchymal transition (EMT)-like response was impaired, which limited cardiac regeneration. Altogether, our study reveals an important function of TGF-β/Smad3 signaling in CM cell cycle progression and EMT process during zebrafish ventricle regeneration.

Zeolitic imidazole frameworks (ZIFs) provide an exciting platform to design and fabricate non-precious-metal carbon-based catalysts for oxygen reduction/evolution reaction (ORR/OER). Herein, we elaborately design a facile enzyme-assisted synthetic strategy that enables to tailor the ZIFs precursors into structural stable decussation shape, which derived Co nanoislands grafted on decussate N-doped carbon nanoleaves (D-Co@NC) can well retain the interpenetrating nanostructure. Benefiting from the combined advantages of compositions and interpenetrating nanostructures, D-Co@NC possesses 5.2 times higher exposed electrochemical active area than the conventional dodecahedral one, thus endowing the superior bifunctional activity toward ORR and OER with a low potential gap (ΔE) of 0.866 V. When applicated in Zn-air battery, the D-Co@NC electrode displays a high peak power density of 115.4 mW cm−2 and energy density of 879.6 Wh kg−1 Zn as well as excellent long-cycling stability more than 200 h, outperforming benchmark catalysts of Pt/C||RuO2. The work provides a promising way to construct ZIFs-derived non-precious-metal electrocatalyst for advanced metal-air batteries.

A chloramphenicol (CAP)-binding aptamer of 80 nucleotides (nt) was reported in 2011. In 2014, it was truncated to 40 nt and has since been used by most researchers, although a careful binding study is still lacking. In this work, binding assays using isothermal titration calorimetry and various DNA-staining dyes were performed. By comparing the truncated aptamer with three control sequences, no specific binding of CAP was observed in each case. The secondary structures of the original and truncated aptamers were analyzed, and it was shown that the likelihood of the truncated aptamer to retain the same binding mechanism as the original sequence is low. We further examined gold nanoparticle (AuNP)-based label-free colorimetric assays. By quantifying the extinction ratio at 620 nm over that at 520 nm, a similar color response was observed regardless of the sequence of DNA, suggesting the color change mainly reflected other events such as the adsorption of CAP by the AuNPs, instead of aptamer binding to CAP. Salt-induced aggregation experiments suggested direct adsorption of CAP on AuNPs. CAP only weakly inhibited DNA adsorption by AuNPs but did not displace pre-adsorbed DNA. Therefore, CAP adsorption by AuNPs needs to be considered when designing related sensors, for example, by using non-aptamer sequences as controls. This work calls for careful confirmation of aptamer binding and control experiments for designing aptamer and AuNP-based biosensors.

We investigate experimentally and numerically the scattering properties of liquid gallium nanoparticles coupled to a thin gold or silver film. The gallium nanoparticles are excited either directly by using inclined white light or indirectly by surface plasmon polaritons generated on the surface of the gold/silver film. In the former case, the scattering spectrum is always dominated by a scattering peak at &sim, 540 nm with a long-wavelength shoulder which is redshifted with increasing diameter of the gallium nanoparticle. Under the excitation of the surface plasmon polaritons, optical resonances with much narrower linewidths, which are dependent on the incidence angle of the white light, appear in the scattering spectra. In this case, the scattering spectrum depends weakly on the diameter of the gallium nanoparticle but the radiation pattern exhibits a strong dependence. In addition, a significant enhancement of electric field is expected in the gap region between the gallium nanoparticles and the gold film based on numerical simulation. As compared with the gallium nanoparticle coupled to the gold film which exhibit mainly yellow and orange colors, vivid scattering light spanning the visible light spectrum can be achieved in the gallium nanoparticles coupled to the silver film by simply varying the incidence angle. Gallium nanoparticles coupled to thin metal films may find potential applications in light&ndash, matter interaction and color display.

Phenol is a ubiquitous pollutant and can contaminate natural water resources. Hence, the removal of phenol from wastewater is of significant importance. A series of biological methods were used to remove phenol based on the natural ability of microorganisms to degrade phenol, but the tolerance mechanism of phenol-degraded strains to phenol are not very clear. Morphological observation on Candida tropicalis showed that phenol caused the reactive oxygen species (ROS) accumulation, damaging the mitochondrial and the endoplasmic reticulum. On the basis of transcriptome data and cell wall susceptibility analysis, it was found that C. tropicalis prevented phenol-caused cell damage through improvement of cell wall resistance, maintenance of high-fidelity DNA replication, intracellular protein homeostasis, organelle integrity, and kept the intracellular phenol concentration at a low level through cell-wall remodeling and removal of excess phenol via MDR/MXR transporters. The knowledge obtained will promote the genetic modification of yeast strains in general to tolerate the high concentrations of phenol and improve their efficiency of phenol degradation.

Transition metal phosphides are promising materials for catalysis and their synthesis procedures commonly require costly or hazardous reagents. Herein, we adopted a yeast-extracted nucleic acid as an environmentally benign non-metal source to develop bifunctional cobalt phosphide/nitrogen-doped porous carbon composites. The single source precursor, i.e., a Co2+–nucleic acid complex was formed by coordination and could be converted to cobalt phosphide/carbon by pyrolysis with the assistance of a molten salt. Material characterization confirmed the formation of a well-crystallized CoP phase, N-doped carbon and hierarchical porous structure. In situ generated reducing gases (CO, H2, PH3, etc.) from the nucleic acid were detected by thermogravimetry-mass spectrometry (TG-MS) and thermogravimetry-infrared spectroscopy (TG-IR); also, they were suggested to be responsible for the transformation of phosphate in the precursor to phosphide in CoP. When applied for model pollutant (bisphenol A, BPA) removal, the developed composite not only exhibited considerable adsorption capability, but also performed well for peroxymonosulfate activation in an advanced oxidation process (AOP). In a two-step removal procedure, 75.5% of BPA was adsorbed in 60 min and the residual 24.5% of BPA could be degraded in 2 min by AOP. Further investigations verified that sulfate radicals, hydroxyl radicals and singlet oxygen were all involved in AOP for catalytic BPA degradation. The exhausted sample could also be regenerated by a facile thermal treatment approach. In this study, we have provided a facile strategy of utilizing inherent biomass components to construct an advanced metal phosphide-containing composite, which may open a new route for the value-added conversion of biomass.

Both MicroRNAs and HMGB1 took part in pathological process of myocardial I/R injury though several signaling pathways. We hypothesized that mircoRNA451 (miR-451), a group of small non-coding RNAs, could improve this injury by inhibiting HMGB1. Male SD rats were randomly distributed into 5 groups and subjected to I/R process. After 24 hours of reperfusion injury, the serum content of CK and LDH, the content of MDA in tissue and activity of SOD were detected; The infarcted areas were defined by TTC staining and Evans Blue; TUNEL staining and cleaved-Caspase 3 were used to test apoptosis; HMGB1 was detected by real-time fluorescence quantitative PCR and Western Blotting. Compared with the I/R and I/R+Ad-GFP group, upregulation of miR-451 could reduce the infarcted areas, cardiomyocytes apoptosis index, expression of cleaved-caspase 3 and content of CK and LDH significantly(P

Background: Phenolics derived from lignocellulose severely influence cell growth and fermentation ability in yeast. Due to its high tolerance for various stresses, Candida tropicalis has recently emerged as a promising strain for the degradation of industrial sewage. Great efforts have been made on studying the degradation machineries of phenol by C. tropicalis, but the global mechanisms underlying its tolerance of high concentrations of phenolics remain ambiguous. Since the substructure and toxicity of phenol are similar to those of other phenolic compounds derived from lignin hydrolysis, we treated C. tropicalis cells with phenol as a representative substance for the phenolic compounds. Results: We found that after treatment with 0.5 g/l, 1.0 g/l, and 2.0 g/l phenol, the growth of C. tropicalis SHC-03 was inhibited, but recovered completely after a lag phase. Although we found that C. tropicalis could degrade phenol when phenol was used as the sole carbon source, it could not degrade phenol in YPD medium, implying that increased tolerance for phenol contributed to the recovery of cell growth. Morphological observation demonstrated that phenol could induce reactive oxygen species (ROS) accumulation, mitochondrial membrane damage, and damage to the endoplasmic reticulum (ER), but did not affect the structural stability of chromatin. On the basis of transcriptome data and cell wall susceptibility analysis, a number of genes related to DNA repair, DNA replication, heat shock protein (HSP)-mediated proteasomal degradation, autophagy, accumulation of fatty acids, cell wall remodeling, and MDR/MXR transporters were found. These genes may play key roles in the increased tolerance of C. tropicalis to phenol stress. Conclusion: C. tropicalis appears to prevent phenol-induced cell damage through maintenance of high-fidelity DNA replication, intracellular protein homeostasis, organelle integrity, and keep the intracellular phenol concentration at a low level through cell-wall remodeling and removal of excess phenol via MDR/MXR transporters. The knowledge obtained from this research provided us with a global understanding of phenolic tolerance mechanisms in C. tropicalis and will promote the genetic modification of yeast strains to develop biological products using lignocellulosic hydrolysates as a carbon resource.

The ecological floating bed (EFB) coupled with zero-valent iron (ZVI) is proposed to treat low carbon-to-nitrogen ratio water. However, the application of ZVI is limited by low electron transfer efficiency. Coupling ZVI with carbon materials may improve the performance. In this study, the EFB with ZVI coupled plant biomass (IB-EFB) was established to enhance denitrification performance and compared to the EFB with ZVI coupled activated carbon (IC-EFB). The results showed that higher denitrification rate was observed in IB-EFB (68.8%) than that in IC-EFB (54.40%), which attributed to the synergistic effect of ZVI and plant biomass. Plant biomass also promoted the electron transfer of ZVI which enhanced the Fe(II)-mediated denitrification. High-throughput sequencing analysis revealed that IB-EFB enriched iron-related denitrifying bacteria more effectively than IC-EFB, and obtained high abundance of phototrophic Fe(II)-oxidizing bacteria Rhodopseudomonas (19.26%). Thus coupling ZVI with plant biomass has a potential for enhanced nitrogen removal in EFB.

C30H24N2O2, monoclinic, P21/c (no. 14), a = 11.4545(6) Å, b = 21.0333(10) Å, c = 10.0604(5) Å, β =103.571(6)°, V = 2356.1(2) Å3, Z = 4, R gt(F) = 0.0652, wR ref(F 2) = 0.1414, T = 289.3(7) K.

Wastewater with low carbon-to-nitrogen (low C/N) ratio has led to residues of nitrogen and phosphorus contaminants due to insufficient carbon source, which received increasing attention. Recently, iron-based materials have been widely used to enhance denitrification and considered to be one of the potential methods for efficient treatment of low C/N ratio wastewater. However, the substance cycles between iron, nitrogen and phosphorus are complicated, the reviews about iron-enhanced nitrogen and phosphorus removal performance needs to be further concluded. The objective of this review is to discuss the role of iron in nitrogen and phosphorus removal, and to provide theoretical support for improving effiencies of wastewater treatment to a certain extent. Firstly, the biological or biochemical processes of iron-mediated nitrogen and phosphorus removal were briefly summarized. The iron-mediated nitrogen removal efficiencies were significantly associated with some conditions affecting biological processes such as iron dosage, or the addition of electron shuttles. The removal pathways and iron dosage were the main factors related to N2O emission. In addition, iron had a great influence on phosphorus accumulating organisms (PAOs) which participated in phosphorus removal. On subsequently, the effects of iron on microbial activity, including promotion and inhibition, were revealed, with the pathways through which iron affected microbes way discussed simultaneously. Thirdly, the combination of iron with other materials was introduced, with the removal efficiencies of composite materials summarized. It was found that iron-based materials showed several advantages when combined with available materials such as activated carbon and metals. Finally, as the challenges for the processes of iron-enhanced nitrogen and phosphorus removal were still present, some suggestions for future research were proposed in this paper. Overall, this review suggests that iron-based materials play a critical role in the biological removal process of nitrogen and phosphorus, which may improve the potentiality of their applications in biological technology.

In this study, a thermo-responsive temporary plugging agent was developed with the property of solution (sol)–gel–sol transition behavior at different temperatures. At low temperature, the material is in the sol state, while increasing temperature led to a stable gel formation, but the gel can transform to sol again upon further heating. This unique behavior was characterized by a series of SEM, FT-IR, XRD, rheology, and viscoelasticity measurements. All scientific results showed noncovalent interactions between the components, which play an important role for the supramolecular gel formation. These findings provide that this system can be applied as a temporary plugging agent by the idea of temperature-induced smart material with the advantages of cross-linker and gel-breaker free. Physical simulation experiment results showed that the material is a solid free fluid with good fluidity at room temperature. After injecting to formation, the fluid gradually transformed to a hard gel around 90 °C with suffic...

Nanogels based Polyethylene glycol diacrylate (PEGDA) attracted much attention due to their promising application in drug delivery and tissue engineering. Here, PEGDA photopolymerization at 532 nm with different initiating systems was investigated. Nanogels can be obtained using single 2′,4′,5′,7′-tetrabromofluorescein disodium salt (EY) as the photoinitiator. To increase the polymerization rate, EY, triethanolamine (TEOA), and diphenyl iodonium hexafluorophosphate (DPI) were investigated as a three-component initiating system. With that initiating system, the conversion of PEGDA double bond was higher than 90 % in 1 min at extremely low irradiation energy density (P= 0.95 mW/cm2). However, the conversion of PEGDA double bond was only 51.5 % in 1 min at the same irradiation energy density when using EY and TEOA as two-component initiating system. Subsequently, the corresponding mechanism of the three-component (EY-TEOA-DPI) initiating system was illustrated. DPI might participate in two ways of photooxidation and reduction, which dramatically improved the polymerization rate. The EY-TEOA-DPI initiating system is promising to be applied in the preparation of multifunctional hydrogels.

Advanced oxidation processes (AOPs) based on peroxymonosulfate (PMS) activation have attracted increasing attention in recent years for organic pollutants removal. Herein, we put forward a facile method to form cobalt phosphide/carbon composite for PMS activation. Combining impregnation approach with pyrolysis treatment enabled the formation of Co2P/biochar composites using baker’s yeast and Co2+ as precursors. The as-synthesized products exhibited excellent catalytic activity for sulfamethoxazole (SMX) degradation over the pH range 3.0–9.0 b y activating PMS. For example, 100% of SMX (20 mg L−1) removal was achieved in 20 min with catalyst dosage of 0.4 g L−1 and PMS loading of 0.4 g L−1. Near zero Co2+ leaching was observed during catalytic reaction, which remarkably lowered the toxic risk of transition metal ion in water. Meanwhile, the reusability of catalyst could be attained by thermal treatment. SMX degradation intermediates were identified by liquid chromatography-mass spectrometry (LC-MS), which facilitated the proposal of possible SMX degradation pathways. Ecological Structure Activity Relationships (ECOSAR) analysis indicated that SMX degradation intermediates may not pose ecological toxicity to the environment. Further investigation verified that Co2P/biochar composites could set off PMS activation not only for the degradation of SMX but also for other sulfonamides. In this study, we not only developed a facile method of utilizing environmental-benign biomass for transition metal phosphide/carbon composite formation, but also achieved highly efficient antibiotic elimination by PMS-based AOP.

1,3,5-benzenetricarboxylate (BTC) and 4,4′-bipyridine (BIPY) are employed in the synthesis of dual ligands Ni-MOFs. The magnetic Ni@CN nanocatalyst is prepared by direct pyrolysis of Ni-MOFs in N2 atmosphere, which exhibited excellent activity in selective hydrogenation of nitrobenzene (NB) to aniline (AN) at 60 °C, 2.0 MPa H2. The conversion of NB can reach 99.1 mol%, and the selectivity of AN is over 99 %. A series of characterizations are obtained by XRD, Raman, XPS, SEM, TEM, TPR and TGA. It is found that the synergic effect of Ni species and N contributes to the increase of catalytic activity of the catalyst. Cycling tests proved that the prepared catalyst could be reused ten times without a visible reduction in catalytic activity of hydrogenation. The excellent stability and activity of Ni@CN nanocatalyst could be assigned to the porosity of carbon material doped with nitrogen, derived from dual ligands Ni-MOFs.

Herein, we report the self-assembly of a mono terpyridine-based building block modified with long alkyl chains, which gives rise to vesicular aggregates in aqueous media. The vesicles are responsive to transition metal ions, and form different kinds of aggregates after metal-ligand coordination. In particular, Ni(ii) shows a unique influence on morphological transitions, whereby vesicles aggregate and fuse upon the addition of Ni(ii) ions. Spectroscopic and morphological studies are highlighted in this work. Furthermore, the formed vesicles could behave as a matrix for encapsulating fluorescent dyes with similar molecular structure via co-assembly, enabling more accurate observation of vesicle aggregation via confocal laser scanning techniques.