An electrochemical sensor derived from Cu-BTB MOF for the efficient detection of diflubenzuron in food and environmental samples.

Diflubenzuron is widely used as a benzoylurea insecticide, and its impact on human health should not be underestimated. Therefore, the detection of its residues in food and the environment is crucial. In this paper, octahedral Cu-BTB was fabricated using a simple hydrothermal method. It served as a precursor for synthesizing Cu/Cu2O/CuO@C with a core-shell structure through annealing, creating an electrochemical sensor for the detection of diflubenzuron. The response of Cu/Cu2O/CuO@C/GCE, expressed as ΔI/I0 exhibited a linear correlation with the logarithm of the diflubenzuron concentration ranging from 1.0 × 10-4 to 1.0 × 10-12 mol·L-1. The limit of detection (LOD) was determined to be 130 fM using differential pulse voltammetry (DPV). The electrochemical sensor demonstrated excellent stability, reproducibility, and anti-interference properties. Moreover, Cu/Cu2O/CuO@C/GCE was successfully employed to quantitatively determine diflubenzuron in actual food samples (tomato and cucumber) and environmental samples (Songhua River water, tap water, and local soil) with good recoveries. Finally, the possible mechanism of Cu/Cu2O/CuO@C/GCE for monitoring diflubenzuron was thoroughly investigated.

Deep Portrait Image Completion and Extrapolation.

General image completion and extrapolation methods often fail on portrait images where parts of the human body need to be recovered -a task that requires accurate human body structure and appearance synthesis. We present a twostage deep learning framework for tackling this problem. In the first stage, given a portrait image with an incomplete human body, we extract a complete, coherent human body structure through a human parsing network, which focuses on structure recovery inside the unknown region with the help of full-body pose estimation. In the second stage, we use an image completion network to fill the unknown region, guided by the structure map recovered in the first stage. For realistic synthesis the completion network is trained with both perceptual loss and conditional adversarial loss.We further propose a face refinement network to improve the fidelity of the synthesized face region. We evaluate our method on publicly-available portrait image datasets, and show that it outperforms other state-of-the-art general image completion methods. Our method enables new portrait image editing applications such as occlusion removal and portrait extrapolation. We further show that the proposed general learning framework can be applied to other types of images, e.g. animal images.

Effects of flooding and aging on phytoremediation of typical polycyclic aromatic hydrocarbons in mangrove sediments by Kandelia obovata seedlings.

A laboratory experiment was conducted to evaluate the effects of flooding and aging on the phytoremediation of naphthalene (Nap), anthracene (Ant) and benzo[a]pyrene (B[a]P) in mangrove sediment by Kandelia obovata (K. obovata) Druce seedlings. Flooding increased dissipation efficiency in the rhizosphere zone from 69.47% to 82.45%, 64.27% to 80.41%, and 61.55% to 78.31% for Nap, Ant and B[a]P, respectively. Aging decreased dissipation efficiency significantly. Further investigation demonstrated that increased enzyme activity was one of important factors for increasing PAHs dissipation rates in flooded mangrove sediments. Moreover, a novel method for in situ quantitative investigation of PAHs distribution in root tissues was established using microscopic fluorescence spectra analysis. Subsequently, the effects of flooding and aging on the distribution of PAHs in root tissues were evaluated using this established method. The order of bioavailable fractions of PAHs after phytoremediation was as follows: non-aging/non-flooding>flooding>aging.

In situ determination mechanisms for the depuration of polycyclic aromatic hydrocarbons adsorbed onto the leaf surfaces of living mangrove seedlings.

To further increase understanding of the mechanisms responsible for air-surface exchange processes, the depuration of adsorbed individual fluorene (Flu), anthracene (Ant), phenanthrene (Phe), fluoranthene (Fla), and pyrene (Pyr) from the leaf surfaces of living Aegiceras corniculatum (Ac) and Kandelia obovata (Ko) seedlings were in situ investigated in real time using laser-induced nanosecond time-resolved fluorescence (LITRF) system. Depuration of the PAHs from the leaf surfaces of the two mangrove seedlings included a rapid and a slow phase, and both of them followed first-order kinetics. Furthermore, significant inter-species and inter-chemical variability existed in terms of the elimination rates and the remaining PAHs residues during the two phases. The rapid phase mainly represented a fast volatilization, of which the volatilization rates moderately correlate with PAH molecular weight, while combined effect of volatilization and photolysis was the dominant mechanism for the slow phase. The retainment of PAHs on the leaf surfaces was associated with the plant species and physicochemical properties of PAHs, especially logKOA.