Excellent photoreduction performance of Cr(vi) over (WO4)2−-doped metal organic framework materials

Negatively charged (WO₄)²⁻ anions doped into 2D layered metal organic frameworks bismuth terephthalate provides a valuable strategy for excellent photoreduction of Cr(vi).

Ultra-small subnano TiOx clusters as excellent cocatalysts for the photocatalytic degradation of tetracycline on plasmonic Ag/AgCl

Subnano TiO_x clusters as cocatalysts on Ag/AgCl exhibit an unparalleled TC photodegradation reaction rate under simulated sunlight irradiation.

Single atomic Au induced dramatic promotion of the photocatalytic activity of TiO2 hollow microspheres

Surface oxygen vacancies (Ov) are used to stabilize single atomic Au on the surfaces of TiO₂ hollow microspheres (TiO₂-HMSs), sharply improving their photoreactivity towards acetone oxidation.

Extracellular vesicles promote esophageal cancer progression by delivering lncZEB1-AS1 between cells

OBJECTIVE

To explore the expression of extracellular vesicle-derived lncZEB1-AS1 in esophageal cancer and its role in esophageal cancer progression.

PATIENTS AND METHODS

The extracellular vesicles (EVs) from esophageal cancer patients (n = 26) and normal subjects (n = 26) were isolated by differential centrifugation. The expression of lncZEB1-AS1 in EVs was detected by Real-time PCR (polymerase chain reaction). The clinical data of normal subjects and patients were analyzed. In addition, the concentration of EVs and lncZEB1-AS1 in blood samples from normal subjects and esophageal cancer patients were assessed. After co-culture of esophageal cancer cell line EC109 and EVs with or without lncZEB1-AS1 knockdown, cell proliferation was detected by CCK-8 assay. The possible target microRNAs of lncZEB1-AS1 in cytoplasm were predicted with miRcode, followed by correlation analysis of lncZEB1-AS1 and miR-214. Through literature review, lncZEB1-AS1 positively regulates ZEB1 expression, which was consistent with our result.

RESULTS

Quantitative Real-time PCR showed that the serum levels of EVs and the content of lncZEB1-AS1 in EVs from esophageal cancer patients were significantly higher than those in normal controls. LncZEB1-AS1 was overexpressed in esophageal cancer cells co-cultured with EVs of esophageal cancer patients. CCK-8 results indicated that EC109 cells co-cultured with EVs of esophageal cancer patients had stronger proliferative capacity. miRcode showed that miR-214 ranked the first of microRNAs that lncZEB1-AS1 might target, and miR-214 expression was significantly increased after lncZEB1-AS1 knockdown in EC109. After overexpressing lncZEB1-AS1 in EC109 or co-culturing EVs of esophageal cancer patients with EC109 cells, we found that lncZEB1-AS1 positively regulates ZEB1. In contrast, interfering with the expression of lncZEB1-AS1 in esophageal cancer cell lines can effectively reduce the expression of ZEB1.

CONCLUSIONS

EVs in the peripheral blood from esophageal cancer patients promote esophageal cancer progression by delivering lncZEB1-AS1 to esophageal cancer cells and targeting miR-214.

Adsorption of methylene blue and Cd(II) onto maleylated modified hydrochar from water

A new carboxylate-functionalized hydrochar (CFHC) was successfully prepared by reaction of hydrochar with maleic anhydride under solvent-free conditions and followed by deprotonating carboxyl group of hydrochar with NaHCO₃ solution. CFHC was characterized using X-ray photoelectron spectroscopy (XPS), elemental analysis (EA), zeta potential, Brunauer-Emmett-Teller surface area (BET) and Fourier-transform infrared spectroscopy (FTIR), and its adsorption properties and mechanisms to methylene blue (MB) and Cd(II) were investigated using the batch method. The isotherm adsorption data were accorded with Langmuir model and the maximum uptakes were 1155.57 and 90.99 mg/g for MB and Cd(II) at the temperature of 303 K, respectively. The joint analysis of batch experiments and characterizations of hydrochar confirmed the π-π interaction was accompanied by electrostatic interaction and hydrogen bond for MB adsorption, while the surface complexation and ion exchange were predominant mechanisms for Cd(II) adsorption. Therefore, a highly effective adsorbent CFHC prepared by a simple and environmentally friendly solid-phase synthesis is a promising candidate for wastewater treatment.

Effects of habitat fragmentation on the genetic diversity and differentiation of Dendrolimus punctatus (Lepidoptera: Lasiocampidae) in Thousand Island Lake, China, based on mitochondrial COI gene sequences

Thousand Island Lake (TIL) is a typical fragmented landscape and an ideal model to study ecological effects of fragmentation. Partial fragments of the mitochondrial cytochrome oxidase subunit I gene of 23 island populations of Dendrolimus punctatus in TIL were sequenced, 141 haplotypes being identified. The number of haplotypes increased significantly with the increase in island area and shape index, whereas no significant correlation was detected between three island attributes (area, shape and isolation) and haplotype diversity. However, the correlation with number of haplotypes was no longer significant when the 'outlier' island JSD (the largest island) was not included. Additionally, we found no significant relationship between geographic distance and genetic distance. Geographic isolation did not obstruct the gene flow among D. punctatus populations, which might be because of the high dispersal capacity of this pine moth. Fragmentation resulted in the conversion of large and continuous habitats into isolated, small and insular patches, which was the primary effect on the genetic diversity of D. punctatus in TIL. The conclusion to emphasize from our research is that habitat fragmentation reduced the biological genetic diversity to some extent, further demonstrating the importance of habitat continuity in biodiversity protection.

A Facile One-Pot Synthesis of Biomimetic Photocatalyst Zn(II)-Porphyrin-Sensitized 3D TiO2 Hollow Nanoboxes and Synergistically Enhanced Visible-Light Degradation

A serials of biomimetic photocatalyst zinc(II) meso-tetra(4-carboxyphenyl)porphyrinato (ZnTCP)-sensitized 3D hierarchical TiO2 hollow nanoboxes (TiO2-HNBs) assembled by six ordered nanosheets with dominant {001} facets exposure (ZnTCP@TiO2-HNBs) have been successfully synthesized by a facile one-pot solvothermal method via a topological transformation process with TiOF2 as template. Infrared spectra (IR), UV-vis spectroscopy, and X-ray photoelectron spectroscopy (XPS) confirmed that ZnTCP played a decisive role in constructing 3D hollow nanoboxes through the formation of ester bond combined to TiO2-HNBs, which also provided a transferring photo excited electrons bridge to sensitize TiO2-HNBs for enhancing visible-light response. Due to the superior sensitization and biomimetic activity of ZnTCP, the photodegradation rate of rhodamine B (RhB) of as-prepared ZnTCP@TiO2-HNBs with ZnTCP/TiOF2 mass ratio of 2% (T-2p) improves 3.6 times compared to that of TiO2-HNBs with a degradation yield of 99% for 2 h under simulated sunlight irradiation (> 420 nm). The enhanced photodegradation ability was attributed to synergistic visible photocatalytic mechanism of biomimetic catalyst, which can not only produce hydroxyl radical (•OH) and superoxide radical (•O2-) coming from the excitation process of ZnTCP sensitized TiO2-HNBs, but also generate singlet oxygen (1O2) that was only provided by biomimetic enzyme porphyrins. Furthermore, the photocatalyst showed good recycling stability and dispersibility after five rounds, ascribed to ZnTCP strong chemical bonding to the support TiO2-HNBs. By means of electrochemical cyclic voltammetry analysis, the effect of central zinc ions and parent porphyrin rings on the redox property of biomimetic catalyst was studied.

Synergistic photocatalytic performance of cobalt tetra(2-hydroxymethyl-1,4-dithiin)porphyrazine loaded on zinc oxide nanoparticles

A new ZnO/CoPz(hmdtn)₄ composite as a highly efficient photocatalyst was successfully prepared by cobalt tetra(2-hydroxymethyl-1,4-dithiin)porphyrazine (CoPz(hmdtn)₄) impregnated onto the surface of ZnO nanoparticles, the photocatalytic performance of ZnO/CoPz(hmdtn)₄ under both simulated sunlight and visible light (λ ≥ 400 nm) irradiation was assessed by degradation of Rhodamine B (RhB) and phenol in aerated conditions. The ZnO/CoPz(hmdtn)₄ manifested much higher photocatalytic activity than pure ZnO and pure CoPz(hmdtn)₄, originating from the synergistic effect between CoPz(hmdtn)₄ and ZnO. Furthermore, the XPS analysis revealed that there may be strong interaction between CoPz(hmdtn)₄ and ZnO. Thereby ZnO/CoPz(hmdtn)₄ with excellent stability can maintain high photocatalytic activity over five runs on the basis of the reusability test. The active species generated in the photocatalytic system were verified by electron spin resonance (ESR) technology. A possible mechanism of the synergistic effect between CoPz(hmdtn)₄ and ZnO was also proposed.

Photocatalytic Oxidation of Acetone Over High Thermally Stable TiO2 Nanosheets With Exposed (001) Facets

Anatase TiO₂ (A-TiO₂) usually exhibits superior photocatalytic activity than rutile TiO₂ (R-TiO₂). However, the phase transformation from A-TiO₂ to R-TiO₂ will inevitably happens when the calcination temperature is up to 600°C, which hampers the practical applications of TiO₂ photocatalysis in hyperthermal situations. In this paper, high energy faceted TiO₂ nanosheets (TiO₂-NSs) with super thermal stability was prepared by calcination of TiOF₂ cubes. With increase in the calcination temperature from 300 to 600°C, TiOF₂ transforms into TiO₂ hollow nanoboxes (TiO₂-HNBs) assembly from TiO₂-NSs via Ostwald Rippening process. Almost all of the TiO₂-HNBs are disassembled into discrete TiO₂-NSs when calcination temperature is higher than 700°C. Phase transformation from A-TiO₂ to R-TiO₂ begins at 1000°C. Only when the calcination temperature is higher than 1200°C can all the TiO₂-NSs transforms into R-TiO₂. The 500°C-calcined sample (T500) exhibits the highest photoreactivity toward acetone oxidation possibly because of the production of high energy TiO₂-NSs with exposed high energy (001) facets and the surface adsorbed fluorine. Surface oxygen vacancy, due to the heat-induced removal of surface adsorbed fluoride ions, is responsible for the high thermal stability of TiO₂-NSs which are prepared by calcination of TiOF₂ cubes.

Remarkable improved electro-Fenton efficiency by electric-field-induced catalysis of CeO2

In this study, we designed a novel combined electro-Fenton system for the treatment of wastewater containing biological recalcitrant using electric-field-induced ceria (CeO₂) as the synergistic catalysts. It was found that by applying this CeO₂ electro-Fenton system, the current efficiency improved from 74.49% to 109.82% within 2.5 min; the removal efficiency for dimethyl phthalate (DMP) increased from 85.5% to 94.9% within 20 min; and the mineralization rate increased from 76.01% to 93.58% after 120 min. The effects of parameters such as the applied potential, electrolyte, and concentration of Fe²⁺ on the current efficiency were systematically studied. Investigations by LSV, zeta titration, X-ray photoelectron spectroscopy (XPS), X-Ray Diffraction (XRD)and electron spin resonance (ESR)revealed the reasons for achieving a current efficiency of over 100% in the CeO₂ electro-Fenton system. A mechanism that involved Brønsted acid sites and the redox cycle of sulfate CeO₂ was proposed.

Inorganic Self-Assembled Bioactive Artificial Proto-Osteocells Inducing Bone Regeneration

Since the discovery of osteoinduction in the early 20th century, innovative biomaterials with osteoinductive potential have emerged as candidates for bone repair. Recently, artificial protocell models have demonstrated great potential for tissue regeneration. Herein, we developed artificial bioactive proto-osteocells by self-assembly of biodegradable biphasic-phosphate particles in the form of aqueous bone morphogenetic protein 2 (BMP2)-containing Pickering emulsions in corn oil to fulfill the release of BMP2 with controlled and local efficacy. These artificial proto-osteocells have the advantage of (1) being directly injected into the target location to avert reported side effects of BMP2, minimizing surgical complications, (2) exhibiting the capability of osteoinduction as shown in both in vitro and in vivo models, and (3) demonstrating calcific deposition locally by utilizing the biodegradable calcium phosphate shell. The efficiency of BMP2 within the artificial proto-osteocells showed 25 times greater bone-inducing potential when compared to the control. This study demonstrates for the first time a new strategy toward utilizing material-based artificial proto-osteocells to tackle medical issues in bone tissue repair and regeneration.

One-step topological preparation of carbon doped and coated TiO2 hollow nanocubes for synergistically enhanced visible photodegradation activity

Various three-dimensional TiO₂ hollow structures have attracted strong scientific and technological attention due to their excellent properties. 3D hierarchical TiO₂ hollow nanocubes (TiO₂-HNBs) are not good candidates for industrial photocatalytic applications due to their large energy gap which is only activated by UV light. Herein, visible-light-responsive carbon doped and coated TiO₂-HNBs (C@TiO₂-HNBs) with a dominant exposure of {001} facets have been prepared via a template-engaged topotactic transformation process using facile one-step solvothermal treatment and a solution containing ethanol, glucose and TiOF₂. The effects of reaction time and glucose/TiOF₂ mass ratio on the structure and performance of C@TiO₂-HNBs were systematically studied. We found that glucose played an important role in providing H₂O during the topological transformation from self-templated TiOF₂ cubes into 3D hierarchical TiO₂ hollow nanocubes versus dehydration reactions, where its main function was as a carbon source. Coated carbon was deposited predominantly on the surface as sp² graphitic carbon in extended p conjugated graphite-like environments, and doped carbon mainly replaced Ti atoms in the surface lattice to form a carbonate structure. The results were confirmed using TEM SEM, EDS, XRD, FT-IR, XPS and Raman spectroscopic studies. The C@TiO₂-HNBs achieved greatly improved RhB photodegradation activity under visible light irradiation. The catalyst prepared with glucose/TiOF₂ at a mass ratio of 0.15 (T24-0.15) showed the highest photodegradation rate of 96% in 40 min, which is 7.0 times higher than those of the TiO₂-HNBs and P25. This new synthetic approach proposes a novel way to construct carbon hybridized 3D hierarchical TiO₂ hollow nanocubes by combining two modification methods, “element doped” and “surface sensitized”, at the same time.

Herein, visible-light-responsive carbon doped and coated TiO₂-HNBs have been prepared via a template-engaged topotactic transformation process.

High performance of a cobalt-nitrogen complex for the reduction and reductive coupling of nitro compounds into amines and their derivatives

Replacement of precious noble metal catalysts with low-cost, non-noble heterogeneous catalysts for chemoselective reduction and reductive coupling of nitro compounds holds tremendous promise for the clean synthesis of nitrogen-containing chemicals. We report a robust cobalt-nitrogen/carbon (Co-N _x /C-800-AT) catalyst for the reduction and reductive coupling of nitro compounds into amines and their derivates. The Co-N _x /C-800-AT catalyst was prepared by the pyrolysis of cobalt phthalocyanine-silica colloid composites and the subsequent removal of silica template and cobalt nanoparticles. The Co-N _x /C-800-AT catalyst showed extremely high activity, chemoselectivity, and stability toward the reduction of nitro compounds with H₂, affording full conversion and >97% selectivity in water after 1.5 hours at 110°C and under a H₂ pressure of 3.5 bar for all cases. The hydrogenation of nitrobenzene over the Co-N _x /C-800-AT catalyst can even be smoothly performed under very mild conditions (40°C and a H₂ pressure of 1 bar) with an aniline yield of 98.7%. Moreover, the Co-N _x /C-800-AT catalyst has high activity toward the transfer hydrogenation of nitrobenzene into aniline and the reductive coupling of nitrobenzene into other derivates with high yields. These processes were carried out in an environmentally friendly manner without base and ligands.