Preparation of core-shell structure Ag@TiO2 plasma photocatalysts and reduction of Cr(VI): Size dependent and LSPR effect.

The poor light absorption and low carrier separation efficiency of Titanium dioxide (TiO2) limit its further application. The introduction of plasma metal Ag have the potential to solve these drawbacks owing to its plasma resonance effect. Thus core-shell structure Ag@TiO2 plasma photocatalysts was prepared by using facile reduction method in this work. More specifically, Ag@TiO2 composite catalysts with different Ag loading amounts were prepared in the presence of surfactant PVP. Ag@TiO2 demonstrates excellent light absorption performance and photoelectric separation efficiency compared with pure TiO2. As a result, it displays excellent performance of Cr(VI) reduction under visible light. The optimal composite catalysts Ag@TiO2-5P achieves exceptional visible-light-driven photocatalytic Cr(VI) reduction efficiency of 0.01416 min-1 that is 2.29 times greater than pure TiO2. To investigate the role of PVP, we also synthesized Ag@TiO2-5 without PVP. The experimental results show that although Ag@TiO2-5 Cr(VI) reduction performance is superior to pure TiO2, it significantly decreases compared with Ag@TiO2-5P. The results of TEM and optoelectronic testing show that agglomeration of Ag particles leads to a decrease in the photoelectric separation efficiency of Ag@TiO2-5. The smaller Ag particles provide more active sites and demonstrating a stronger overall local surface plasmon resonance (LSPR) effect. DMPO spin-trapping ESR spectra testing indicates that ∙O2- and ∙OH are the main reactive species. This research provides a potential strategy to prepare Ag-based plasma photocatalysts for environment protection.

Lung inflammation perturbation by engineered nanoparticles.

In recent years, the unique and diverse physicochemical properties of nanoparticles have brought about their wide use in many fields; however, it is necessary to better understand the possible human health risks caused by their release in the environment. Although the adverse health effects of nanoparticles have been proposed and are still being clarified, their effects on lung health have not been fully studied. In this review, we focus on the latest research progress on the pulmonary toxic effects of nanoparticles, and we summarized their disturbance of the pulmonary inflammatory response. First, the activation of lung inflammation by nanoparticles was reviewed. Second, we discussed how further exposure to nanoparticles aggravated the ongoing lung inflammation. Third, we summarized the inhibition of the ongoing lung inflammation by nanoparticles loaded with anti-inflammatory drugs. Forth, we introduced how the physicochemical properties of nanoparticles affect the related pulmonary inflammatory disturbance. Finally, we discussed the main gaps in current research and the challenges and countermeasures in future research.

Preliminary Exploration of Metabolic Mechanisms in Copper-Exposed Sepia esculenta Based on Transcriptome Analysis.

As a common and high-concentration heavy metal in the ocean, Cu can induce metal toxicity and significantly affect the metabolic function of marine organisms. Sepia esculenta is an important economic cephalopod found along the east coast of China, the growth, movement, and reproduction of which are all affected by heavy metals. Hitherto, the specific metabolic mechanism of heavy-metal exposure in S. esculenta is still unclear. In this study, we identified 1131 DEGs through transcriptome analysis of larval S. esculenta within 24 h of Cu exposure. GO and KEGG functional enrichment analysis results indicated that Cu exposure may affect purine metabolism, protein digestion and absorption, cholesterol metabolism, and other metabolic processes in S. esculenta larvae. It is worth noting that in this study we explore metabolic mechanism of Cu-exposed S. esculenta larvae through the comprehensive analysis of protein-protein interaction network and KEGG enrichment analysis for the first time and find 20 identified key and hub genes such as CYP7A1, CYP3A11, and ABCA1. Based on their expression, we preliminarily speculate that Cu exposure may inhibit multiple metabolic processes and induce metabolic disorders. Our results lay a foundation for further understanding the metabolic mechanism of S. esculenta against heavy metals and provide theoretical help for S. esculenta artificial breeding.

Room Temperature Engineering Crystal Facet of Cu2O for Photocatalytic Degradation of Methyl Orange.

Cuprous oxide (Cu2O) has received enormous interest for photocatalysis owing to its narrow band gap of 2.17 eV, which is beneficial for visible-light absorption. In this work, we succeeded in synthesizing Cu2O nanocrystals with two morphologies, cube and sphere, at room temperature via a simple wet-chemistry strategy. The morphologies of Cu2O change from cube to sphere when adding PVP from 0 g to 4 g and the mainly exposed crystal faces of cubic and spherical Cu2O are (100) and (111), respectively. The photocatalytic properties of the as-prepared Cu2O were evaluated by the photocatalytic degradation of methyl orange (MO). Cubic Cu2O(100) showed excellent photocatalytic activity. After the optical and photoelectric properties were investigated, we found that cubic Cu2O(100) has better photoelectric separation efficiency than spherical Cu2O(111). Finally, the possible mechanism was proposed for cubic Cu2O(100) degrading MO under visible light.

Differential gene expression analysis related to sperm storage in spermathecas of Amphioctopus fangsiao.

Sperm storage in the female body is an important strategy in animal reproductive behavior. Amphioctopus fangsiao is an economically important cephalopod that has a sperm storage period of up to seven months. There are few studies concerning the mechanism of sperm storage in A. fangsiao. In this study, we performed transcriptome gene expression profiling of the oviductal glands at different phases (presence and absence of sperm storage). In total, 7943 differentially expressed genes (DEGs) comprising 4737 upregulated and 3206 downregulated genes were identified. GO and KEGG enrichment analyses were used to search for sperm storage-related genes. A protein interaction network was constructed to examine the interactions between genes. Nineteen genes associated with immunity, apoptosis, and autophagy were obtained and verified by qRT-PCR. This is the first comprehensive analysis of sperm storage-related genes in A. fangsiao. The results provide basic insights into the complex sperm storage mechanism of A. fangsiao.

Mechanism of Heterogeneous Bubble Nucleation in Polymer Blend Foaming.

A three-dimensional heterogeneous bubble nucleation model is constructed to provide a reasonable explanation at the molecular level for the foaming mechanism of polypropylene (PP) and polystyrene (PS) blends. CO2 solubilities and supersaturation rations are quantitatively calculated to help interpret the contribution of each phase of the blend in the CO2 dissolution stage. The spatial density profiles of polymer/CO2 binary melt around different polymer chains are presented to give an intuitive perspective to the thermodynamic driving force. The predicted interfacial tension and contact angles of critical bubbles provide valid evidence to distinguish the wettability of CO2 in different regions. The values of predicted free-energy barriers, critical radii, and nucleation number densities imply that bubbles that nucleate in the PP and PS blend interfacial region attached to the PS-rich phase achieve the smallest size and largest number density. The reliability of the theoretical model has been tested by partial available experimental data.

A coumarin-fused 'off-on' fluorescent probe for highly selective detection of hydrazine.

Hydrazine is a kind of widely used industrial raw material and a toxic biochemical reagent. Due to its toxic to organisms, hydrazine has been classified to be a hazardous environmental pollutant. It is urgent to develop fluorescent probe tools for selective sensitivity detection of hydrazine in the environment and the body. We developed here a new coumarin-based fluorescent probe for hydrazine detection. The probe can selectively detect hydrazine over other environmental and endogenous interfering analytes with a large off-on fluorescence response. The detection limit is 8.55 ppb, which is well below the allowed threshold limit value. The sensing mechanism is hydrazine-induced pyrazole ring formation, which is confirmed by HRMS and DFT calculation methods. Additionally, the probe could also be applied for hydrazine imaging in living HeLa cells.

The mechanism of roughness-induced CO2 microbubble nucleation in polypropylene foaming.

Within the framework of classical density functional theory, the thermodynamic driving forces for CO2 microbubble nucleation have been quantitatively evaluated in the foaming of polypropylene containing amorphous and crystalline structures. After the addition of fluorinated polyhedral oligomeric silsesquioxane particles into the polypropylene matrix, we construct different composite surfaces with nanoscale roughness for bubble nucleation. Meanwhile, as the dissolved CO2 molecules increase, the corresponding CO2/PP binary melts can be formulated in the systems. Due to the roughness effect coupled with the weak interactions of particle-PP, PP chains in the binary melts are depleted from the surfaces, leading to a significant enhancement of osmotic pressure in depletion regions. During the foaming process, a large number of dissolved CO2 molecules are squeezed into the regions, thus local supersaturations are dramatically improved, and the energy barriers for bubble nucleation are dramatically reduced. Moreover, when the nanocomposite surfaces display ordered nanoscale patterns, the energy barriers can be further reduced to their respective minimum values, and the bubble number densities reach their maximum. Accordingly, the bubble number densities can be enhanced by 4 or 5 orders of magnitude for bubbles nucleated on the crystalline or amorphous PP nanocomposite surface. In contrast, when the foaming pressure is increased from 15 to 20 MPa, the elevated bubble number density in the foaming PP matrix is less than one order of magnitude. As a result, the enhancement of local supersaturation induced by the controlled nanoscale roughness is much more effective than that of bulk supersaturation given by high pressure.

N'-(3-Hy-droxy-benzyl-idene)-4-methyl-benzohydrazide.

The title compound, C(15)H(14)N(2)O(2), was obtained from the reaction of 3-hy-droxy-benzaldhyde and 4-methyl-benzo-hydrazide in methanol. In the mol-ecule, the benzene rings form a dihedral angle of 2.9 (3)°. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds link the mol-ecules into layers parallel to (101). The crystal packing also exhibits π-π inter-actions between the aromatic rings [centroid-centroid distance = 3.686 (4) Å].

N'-(2-Hy-droxy-4-meth-oxy-benzyl-idene)-4-methyl-benzohydrazide.

The asymmetric unit of the title compound, C(16)H(16)N(2)O(3), contains four independent mol-ecules with different conformations; the dihedral angles between the two benzene rings in the mol-ecules are 39.7 (3), 45.4 (3), 50.6 (3) and 51.6 (3)°. Intramolecular O-H⋯N hydrogen bonds are observed in the molecule. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into two crystallographically independent chains propagating in [010], and each chain is formed by two alternating independent mol-ecules. Weak C-H⋯O inter-actions also occur.

2-[(5-Chloro-2-oxidobenzyl-idene)aza-nium-yl]-2-methyl-propane-1,3-diol.

The title compound, C(11)H(14)ClNO(3), was prepared by the condensation of equimolar quanti-ties of 5-chloro-salicyl-aldehyde and 2-amino-2-methyl-propane-1,3-diol in methanol. In the crystal, it exists in the zwitterionic form, with nominal proton transfer from the phenol group to the imine N atom. This results in the formation of an intra-molecular N-H⋯O hydrogen bond, which generates an S(6) ring. Inter-molecular O-H⋯O hydrogen bonds arise from the hy-droxy groups, forming (001) sheets.

Graphene-based solid-phase extraction combined with flame atomic absorption spectrometry for a sensitive determination of trace amounts of lead in environmental water and vegetable samples.

Graphene, a novel class of carbon nanostructures, has great promise for use as sorbent materials because of its ultrahigh specific surface area. A new method using a column packed with graphene as sorbent was developed for the preconcentration of trace amounts of lead (Pb) using dithizone as chelating reagent prior to its determination by flame atomic absorption spectrometry. Some effective parameters on the extraction and complex formation were selected and optimized. Under optimum conditions, the calibration graph was linear in the concentration range of 10.0-600.0 µg L(-1) with a detection limit of 0.61 µg L(-1). The relative standard deviation for ten replicate measurements of 20.0 and 400.0 µg L(-1) of Pb were 3.56 and 3.25%, respectively. Comparative studies showed that graphene is superior to other adsorbents including C18 silica, graphitic carbon, and single- and multi-walled carbon nanotubes for the extraction of Pb. The proposed method was successfully applied in the analysis of environmental water and vegetable samples. Good spiked recoveries over the range of 95.3-100.4% were obtained. This work not only proposes a useful method for sample preconcentration, but also reveals the great potential of graphene as an excellent sorbent material in analytical processes.

(E)-N'-(4-Hy-droxy-benzyl-idene)-3-nitro-benzohydrazide.

The mol-ecule of the title compound, C(14)H(11)N(3)O(4), assumes an E conformation about the C=N double bond. The benzene rings form a dihedral angle of 3.9 (2)°. The crystal structure is stabilized by N-H⋯O, O-H⋯N, O-H⋯O and C-H⋯O hydrogen bonds, forming layers parallel to (101). In addition, intra-layer π-π stacking inter-actions [centroid-centroid distance = 3.635 (2) Å] are observed.

2-Fluoro-N'-[(2-hydroxynaphthalen-1-yl)methylidene]benzohydrazide.

In the title mol-ecule, C(18)H(13)FN(2)O(2), the hy-droxy group is involved in an intra-molecular O-H⋯N hydrogen bond. The naphthyl ring system and the benzene ring form a dihedral angle of 31.0 (2)°. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into chains propagating in [101].

2-Bromo-4-chloro-6-(cyclo-hexyl-imino-meth-yl)phenol.

The title compound, C(13)H(15)BrClNO, was prepared by the condensation of equimolar quanti-ties of 3-bromo-5-chloro-salicyl-aldehyde with cyclo-hexyl-amine in methanol. There is an intra-molecular O-H⋯N hydrogen bond in the mol-ecule. The cyclo-hexyl ring adopts a chair conformation.

N'-(5-Bromo-2-hy-droxy-benzyl-idene)-4-nitro-benzohydrazide methanol monosolvate.

In the title compound, C(14)H(10)BrN(3)O(4)·CH(4)O, the benzohydrazide mol-ecule is nearly planar [maximum deviation = 0.110 (2) Å]. The mean planes of the two benzene rings make a dihedral angle of 8.4 (3)°. In the benzohydrazide mol-ecule, there is an intra-molecular O-H⋯N hydrogen bond and the NH group is hydrogen bonded to the methanol solvent mol-ecule. In the crystal, inter-molecular O-H⋯O hydrogen bonds involving the methanol solvent mol-ecule link the benzohydrazide mol-ecules to form chains which propagate along the a axis.

N'-(3,5-Dibromo-2-hy-droxy-benzyl-idene)-4-nitro-benzohydrazide methanol monosolvate.

The title compound, C(14)H(9)Br(2)N(3)O(4)·CH(4)O, was obtained as the product of the reaction of 3,5-dibromo-salicyl-aldehyde with 4-nitro-benzohydrazide in methanol. The benzohydrazide mol-ecule is nearly planar, with a maximum deviation of 0.126 (2) Å. The mean planes of the two benzene rings make a dihedral angle of 9.3 (3)°. Intra-molecular O-H⋯N and O-H⋯Br inter-actions are observed in the benzohydrazide mol-ecule. In the crystal, pairs of adjacent benzohydrazide mol-ecules are linked by two methanol mol-ecules through inter-molecular O-H⋯O and N-H⋯O hydrogen bonds, forming a dimer.

Development of dispersive liquid-liquid microextraction based on solidification of floating organic drop for the determination of trace nickel.

A liquid-phase microextraction technique was developed using dispersive liquid-liquid microextraction based on solidification of floating organic drop combined with flame atomic absorption spectrometry, for the extraction and determination of trace amounts of nickel in water samples. Microextraction efficiency factors, such as the type and volume of extraction and dispersive solvents, pH, extraction time, the chelating agent amount, and ionic strength, were investigated and optimized. Under optimum conditions, the calibration graph was linear in the range of 4.23-250 µg L(-1) with a detection limit of 1.27 µg L(-1). The relative standard deviation for ten replicate measurements of 10 and 100 µg L(-1) of nickel were 3.21% and 2.55%, respectively. The proposed method was assessed through the analysis of certified reference water or recovery experiments.

N'-[(2-Methoxynaphthalen-1-yl)methyl-idene]-4-methyl-benzohydrazide.

In the title compound, C(20)H(18)N(2)O(2), the mean planes of the naphthyl system and the benzene ring form a dihedral angle of 88.48 (10)°. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into C(4) chains, which propagate along the b-axis direction.

[Study on the interaction of luteolin with human serum albumin by fluorescence quenching method].

The interaction between luteolin and human serum albumin (HSA) was studied by using fluorescence quenching spectra, synchronous fluorescence spectra and ultra-violet spectra. The results showed that luteolin had a strong ability to quench the fluorescence of HAS The Stern-Volmer curve of the fluorescence quenching of HSA by luteolin indicated that the mechanism behind the quenching between luteolin and HSA was a static quenching. According to the Forster theory of non-radiation energy transfer, the binding distances (r) and the binding constants (KA) were calculated. The thermodynamic parameters showed that the interaction between luteolin and HSA was driven mainly by hydrophobic force. Synchronous spectra were used to investigate the conformational changes of HSA.