Recent Advances in Transfer-Free Synthesis of High-Quality Graphene.

High-quality graphene obtained by chemical vapor deposition (CVD) technique holds significant importance in constructing innovative electronic and optoelectronic devices. Direct growth of graphene over target substrates readily eliminates cumbersome transfer processes, offering compatibility with practical application scenarios. Recent years have witnessed growing strategic endeavors in the preparation of transfer-free graphene with favorable quality. Nevertheless, timely review articles on this topic are still scarce. In this contribution, a systematic summary of recent advances in transfer-free synthesis of high-quality graphene on insulating substrates, with a focus on discussing synthetic strategies designed by elevating reaction temperature, confining gas flow, introducing growth promotor and regulating substrate surface is presented.

Surface modification of rare earth Sm-doped WO3 films through polydopamine for enhanced electrochromic energy storage performance.

Electrochromic materials (ECMs) could exhibit reversible color changes upon application of the external electric field, which exhibits huge application prospects in smart windows, energy storage devices, and displays. For the practical application of ECMs, the fast response speed and long cyclic stability are urgent. In this work, the nanoporous Sm-doped WO3 (WSm) films were constructed using hydrothermal technology, then polydopamine (PDA) was modified on the surface of WSm film to obtain the WSm/Px (x = 0.25, 0.5, 1.0, and 2.0) hybrid films. WSm/Px hybrid films displayed high optical contrast and large areal capacitance. In addition, in comparison with WSm film, the WSm/Px hybrid films exhibited faster response speed and better cyclic stability because PDA film enhanced the interface ion transport ability and electrochemical structural stability of the nanoporous WSm film. Notably, the WSm/P1.0 hybrid film displayed the colored/bleached times of 7.4/2.9 s, retained 90.2% of the primitive optical contrast (68.5%) after 5000 electrochromic cycles. Furthermore, the areal capacitance of WSm film could be increased by 224% through the modification of the PDA. Therefore, WSm/Px hybrid films are great prospects for electrochromic energy-saving and storage windows.

Reduced cadmium toxicity in rapeseed via alteration of root properties and accelerated plant growth by a nitrogen-fixing bacterium.

Cd accumulation in crops has become a global environmental problem because it endangers human health. Screening for microorganisms that can reduce Cd accumulation in crops is a possible measure to address this issue. However, success has been limited, and most previous work did not involve bacteria. In the present study, a strain of N-fixing bacteria (Burkholderia spp.) that exhibits high levels of Cd tolerance was screened. The ability of this bacterium to reduce Cd in rapeseed was then assessed in sterile hydroponic and open soil culture systems. In the hydroponic system, the Burkholderia inoculum promoted Cd fixation in rapeseed roots and thus reduced Cd enrichment in aboveground edible tissues (leaves). The mechanisms were related to increased activity of pectin methylesterase in root cell walls, and the transformation of the chemical form of root Cd from "active" (NaCl-extracted) to "inert" (HCl-extracted and residual Cd) states. Additionally, Burkholderia accelerated plant growth, thus shortening the period in which the plant is available for Cd absorption. In the soil culture system, Burkholderia also reduced Cd enrichment in rapeseed leaves in the presence of other microorganisms. Thus, the bacterial strain shows potential for broad application for reducing the accumulation of Cd in crops.

Efficient adsorption of diclofenac sodium in water by a novel functionalized cellulose aerogel.

In this work, a novel cellulose aerogel (CNC-PVAm/rGO) was fabricated using cellulose nanocrystalline (CNC) modified with polyvinylamine (PVAm) and reduced graphene oxide (rGO). The resultant CNC-PVAm/rGO was then applied for the adsorption of diclofenac sodium (DCF), a typical non-steroidal anti-inflammatory drug. Characterization using ultra-high-resolution field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and the Brunauer-Emmett-Teller surface area revealed that the obtained CNC-PVAm/rGO displayed an evident 3D porous structure, which had an ultralight weight, good recovery, abundant surface functional groups (e.g., -NH2 and -OH), and rGO nanosheets. In addition, the material presented a stable crystal structure and large specific surface area (105.73 m2 g-1). During the adsorption of DCF, the CNC-PVAm/rGO aerogel showed a rather excellent adsorption performance, with a maximum adsorption capacity (qmax) of 605.87 mg g-1, which was approximately 53 times larger than that of the bare CNC aerogel (11.45 mg g-1). The adsorption performance of CNC-PVAm/rGO was also better than that of other reported adsorbents. The adsorption of DCF to CNC-PVAm/rGO obeyed the Langmuir isotherm and pseudo-second-order kinetic models, and underwent a spontaneous exothermic process. Moreover, DCF was easily desorbed from CNC-PVAm/rGO with sodium hydroxide solution (0.1 mol L-1), and the absorbent could be reused four times. The introduction of PVAm and rGO to the CNC-PVAm/rGO aerogel also greatly enhanced electrostatic interactions, π-π interactions, and hydrophobic effects. These enhancements significantly promoted the hydrogen bonding interactions between the DCF molecules and CNC-PVAm/rGO, thus resulting in a large improvement in the adsorption performance of the aerogel.

Design, Synthesis and Antibacterial Evaluation of Some New 2-Phenyl-quinoline-4-carboxylic Acid Derivatives.

A series of new 2-phenyl-quinoline-4-carboxylic acid derivatives was synthesized starting from aniline, 2-nitrobenzaldehyde, pyruvic acid followed by Doebner reaction, amidation, reduction, acylation and amination. All of the newly-synthesized compounds were characterized by ¹H-NMR, (13)C-NMR and HRMS. The antibacterial activities of these compounds against Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis), as well as one strain of methicillin-resistant Staphylococcus aureus (MRSA) bacteria were evaluated by the agar diffusion method (zone of inhibition) and a broth dilution method (minimum inhibitory concentration (MIC)), and their structure-activity relationships were obtained and discussed. The results revealed that some compounds displayed good antibacterial activity against Staphylococcus aureus, and Compounds 5a4 and 5a7 showed the best inhibition with an MIC value of 64 µg/mL against Staphylococcus aureus and with an MIC value of 128 µg/mL against Escherichia coli, respectively. The results of the MTT assay illustrated the low cytotoxicity of Compound 5a4.

Evaluation of iron-binding activity of collagen peptides prepared from the scales of four cultivated fishes in Taiwan.

Iron deficiency is one of the most concerning deficiency problems in the world. It may generate several adverse effects such as iron deficiency anemia (IDA) and reduced physical and intellectual working capacity. The aim of this study is to evaluate the Fe(II)-binding activity of collagen peptides from fishery by-products. Lates calcarifer, Mugil cephalus, Chanos chanos, and Oreochromis spp are four major cultivated fishes in Taiwan; thousands of scales of these fish are wasted without valuable utilization. In this study, scales of these fish were hydrolyzed by papain plus flavourzyme. Collagen peptides were obtained and compared for their Fe(II)-binding activity. Collagen peptides from Chanos chanos showed the highest Fe(II)-binding activity, followed by those from Lates calcarifer and Mugil cephalus; that from Oreochromis spp exhibited the lowest one. Fe(II)-binding activity of collagen peptides from fish scales was also confirmed with a dialysis method. Molecular weight (MW) distributions of the collagen peptides from scales of four fish are all < 10 kDa, and averaged 1.3 kDa. Hydrolysates of fish scales were further partially purified with ion exchange chromatography. Fractions having Fe(II)-binding activity were obtained and their activity compared. Data obtained showed that collagen peptides from fish scales did have Fe(II)-binding activity. This is the first observation elucidating fish scale collagen possessing this functionality. The results from this study also indicated that collagen peptides from fish scales could be applied in industry as a bioresource.

[Effects of green space vegetation canopy pattern on the microclimate in residential quarters of Shenzhen City].

Based on field survey and landscape pattern analysis, this paper studied the effects of green space vegetation canopy on the microclimate in three typical residential quarters in Shenzhen City. In each of the residential quarters, 22-26 points were chosen for meteorological observation; and around each of the observation points, a 20 m x 20 m quadrat was installed, with each quadrat divided into two different patches, one covered by vegetation canopy and the another no-covered. The patch density index (D(p)) and contagion index (CONTAG) in each quadrat were calculated to analyze the relationships between vegetation canopy pattern index and microclimate in each point. The results showed that the green space vegetation canopy pattern in Shenzhen had significant regulation effect on temperature and humidity. The cooling effect was mainly from the shading effect of vegetation, and also, correlated with vegetation quantity. The increase in the CONTAG of bare surface had obvious negative effects on the regulation effect of vegetation on microclimate. The regulation capability of green space vegetation on the temperature and humidity in residential quarters mainly came from tall arbor species.