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1.
Langmuir ; 40(29): 15301-15309, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-38982808

RESUMO

Natural mineral-based advanced oxidation processes (AOPs) are now receiving increasing attention for the efficient degradation of pollutants. In this work, we used a common reducing agent (NaBH4) to treat natural Hematite to obtain modified Hematite (Hematite-(R)) and applied it to activate peracetic acid (PAA) for efficient degradation of cefazolin (CFZ). Compared with Hematite, the Hematite-(R)/PAA system increased the degradation rate of CFZ by 21.7% within 80 min under neutral conditions. Scavenging experiments and electron paramagnetic resonance (EPR) technology were introduced to identify the principal roles of 1O2, CH3C(O)OO•, and •OH for CFZ removal over the Hematite-(R)/PAA process. The outstanding capability of Hematite-(R) could be mainly due to the higher percentage of Fe(II) (52%) on the surface of catalysts. Furthermore, the possible degradation pathways of CFZ were explored. Moreover, the Hematite-(R)/PAA process showed a superior CFZ removal efficiency with a wide initial pH scope of 1.0-9.0. The degradation efficiency of CFZ showed a negligible effect in the presence of Cl-, SO42-, and NO3-, while significant inhibition was recorded after the addition of H2PO4- and CO32-. The inhibition of humic acid (HA) on CFZ degradation via the Hematite-(R)/PAA process showed an obvious concentration dependence. This work could provide strong support for the use of natural Hematite in water purification.

2.
Langmuir ; 40(17): 9020-9027, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38632903

RESUMO

We prepared BiOCl, BiO(ClBr), BiO(ClBrI), and BiO[ClBrI(CO3)0.5] materials using a simple coprecipitation method. It was found that adjusting the number of anions in the anion layer was conducive to adjusting the band structure of BiOX and could effectively promote the migration and separation of photogenerated carriers, thus improving the photocatalytic activity. We first selected methyl orange (MO) as the study pollutant and compared it with BiOCl, BiO(ClBr), and BiO(ClBrI). The first-order kinetic constants of MO degradation by BiO[ClBrI(CO3)0.5] increased by 90.3, 33.9, and 3.1 times, respectively. The photocatalytic degradation rate of methylene blue by BiO[ClBrI(CO3)0.5] was 89.5%, indicating the excellent photocatalytic performance of BiO[ClBrI(CO3)0.5]. The stability of BiO[ClBrI(CO3)0.5] was demonstrated through cyclic experiments and XRD analysis before and after the reaction. The photocatalytic degradation of MO by BiO[ClBrI(CO3)0.5] showed that h+ and 1O2 were the main active oxidizing species and •O2- was the secondary active substance. Overall, our work provides new ideas for the synthesis and degradation of organic pollutants by using two-dimensional anionic high-entropy materials.

3.
Langmuir ; 40(3): 1848-1857, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38183664

RESUMO

Elaborating the specific reactive oxygen species (ROS) involved in the photocatalytic degradation of atrazine (ATZ) is of great significance for elucidating the underlying mechanism. This study provided conclusive evidence that hydroxyl radicals (·OH) were the primary ROS responsible for the efficient photocatalytic degradation of ATZ, thereby questioning the reliability of widely adopted radical quenching techniques in discerning authentic ROS species. As an illustration, oxygen-modified g-C3N4 (OCN) was prepared to counteract the limitations of pristine g-C3N4 (CN). Comparative assessments between CN and OCN revealed a remarkable 10.44-fold improvement in the photocatalytic degradation of ATZ by OCN. This enhancement was ascribed to the increased content of C-O functional groups on the surface of the OCN, which facilitated the conversion of superoxide radicals (·O2-) into hydrogen peroxide (H2O2), subsequently leading to the generation of ·OH. The increased production of ·OH contributed to the efficient dealkylation, dechlorination, and hydroxylation of ATZ. Furthermore, toxicity assessments revealed a significant reduction in ATZ toxicity following its photocatalytic degradation by OCN. This study sheds light on the intricate interconversion of ROS and offers valuable mechanistic insights into the photocatalytic degradation of ATZ.

4.
Sensors (Basel) ; 24(5)2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38474994

RESUMO

Graph neural networks (GNNs) have been proven to be an ideal approach to deal with irregular point clouds, but involve massive computations for searching neighboring points in the graph, which limits their application in large-scale LiDAR point cloud processing. Down-sampling is a straightforward and indispensable step in current GNN-based 3D detectors to reduce the computational burden of the model, but the commonly used down-sampling methods cannot distinguish the categories of the LiDAR points, which leads to an inability to effectively improve the computational efficiency of the GNN models without affecting their detection accuracy. In this paper, we propose (1) a LiDAR point cloud pre-segmented down-sampling (PSD) method that can selectively reduce background points while preserving the foreground object points during the process, greatly improving the computational efficiency of the model without affecting its 3D detection accuracy. (2) A lightweight GNN-based 3D detector that can extract point features and detect objects from the raw down-sampled LiDAR point cloud directly without any pre-transformation. We test the proposed model on the KITTI 3D Object Detection Benchmark, and the results demonstrate its effectiveness and efficiency for autonomous driving 3D object detection.

5.
Sensors (Basel) ; 24(5)2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38475124

RESUMO

The lack of discernible vehicle contour features in low-light conditions poses a formidable challenge for nighttime vehicle detection under hardware cost constraints. Addressing this issue, an enhanced histogram of oriented gradients (HOGs) approach is introduced to extract relevant vehicle features. Initially, vehicle lights are extracted using a combination of background illumination removal and a saliency model. Subsequently, these lights are integrated with a template-based approach to delineate regions containing potential vehicles. In the next step, the fusion of superpixel and HOG (S-HOG) features within these regions is performed, and the support vector machine (SVM) is employed for classification. A non-maximum suppression (NMS) method is applied to eliminate overlapping areas, incorporating the fusion of vertical histograms of symmetrical features of oriented gradients (V-HOGs). Finally, the Kalman filter is utilized for tracking candidate vehicles over time. Experimental results demonstrate a significant improvement in the accuracy of vehicle recognition in nighttime scenarios with the proposed method.

6.
Angew Chem Int Ed Engl ; 63(14): e202319216, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38337143

RESUMO

The synthesis of hydrogen peroxide through artificial photosynthesis is a green and promising technology with advantages in sustainability, economy and safety. However, superoxide radical (⋅O2 -), an important intermediate in photocatalytic oxygen reduction to H2O2 production, has strong oxidizing properties that potentially destabilize the catalyst. Therefore, avoiding the accumulation of ⋅O2 - for its rapid conversion to H2O2 is of paramount significance in improving catalyst stability and H2O2 yield. In this work, a strategy was developed to utilize protonated groups for the rapid depletion of converted ⋅O2 -, thereby the efficiency of photocatalytic synthesis of H2O2 from CN was successfully enhanced by 47-fold. The experimental findings demonstrated that polydopamine not only improved carrier separation efficiency, and more importantly, provided the adsorption reduction active site for ⋅O2 - for efficient H2O2 production. This work offers a versatile approach for synthesizing efficient and stable photocatalysts.

7.
Angew Chem Int Ed Engl ; 63(21): e202315802, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38453646

RESUMO

The development of nonpyrolytic catalysts featuring precisely defined active sites represents an effective strategy for investigating the fundamental relationship between the catalytic activity of oxygen reduction reaction (ORR) catalysts and their local coordination environments. In this study, we have synthesized a series of model electrocatalysts with well-defined CoN4 centers and nonplanar symmetric coordination structures. These catalysts were prepared by a sequential process involving the chelation of cobalt salts and 1,10-phenanthroline-based ligands with various substituent groups (phen(X), where X=OH, CH3, H, Br, Cl) onto covalent triazine frameworks (CTFs). By modulating the electron-donating or electron-withdrawing properties of the substituent groups on the phen-based ligands, the electron density surrounding the CoN4 centers was effectively controlled. Our results demonstrated a direct correlation between the catalytic activity of the CoN4 centers and the electron-donating ability of the substituent group on the phenanthroline ligands. Notably, the catalyst denoted as BCTF-Co-phen(OH), featuring the electron-donating OH group, exhibited the highest ORR catalytic activity. This custom-crafted catalyst achieved a remarkable half-wave potential of up to 0.80 V vs. RHE and an impressive turnover frequency (TOF) value of 47.4×10-3 Hz at 0.80 V vs. RHE in an alkaline environment.

8.
Small ; 19(35): e2300392, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37127883

RESUMO

Second near infrared (NIR-II, 1000-1700 nm) fluorescence lifetime imaging is a powerful tool for biosensing, anti-counterfeiting, and multiplex imaging. However, the low photoluminescence quantum yield (PLQY) of fluorescence probes in NIR-II region limits its data collecting efficiency and accuracy, especially in multiplex molecular imaging in vivo. To solve this problem, lanthanide-doped nanoparticles (NPs) ß-NaErF4 : 2%Ce@NaYbF4 @NaYF4 with high PLQY and tunable PL lifetime through multi-ion doping and core-shell structural design, are presented. The obtained internal PLQY can reach up to 50.1% in cyclohexane and 9.2% in water under excitation at 980 nm. Inspired by the above results, a fast NIR-II fluorescence lifetime imaging of whole-body vascular in mice is successfully performed by using the homebuilt fluorescence lifetime imaging system, which reveals a murine abdominal capillary network with low background. A further demonstration of fluorescence lifetime multiplex imaging is carried out in molecular imaging of atherosclerosis cells and different organs in vivo through NPs conjugating with specific peptides and different injection modalities, respectively. These results demonstrate that the high PLQY NPs combined with the homebuilt fluorescence lifetime imaging system can realize a fast and high signal-to-noise fluorescence lifetime imaging; thus, opening a road for multiplex molecular imaging of atherosclerosis.


Assuntos
Aterosclerose , Elementos da Série dos Lantanídeos , Nanopartículas , Animais , Camundongos , Elementos da Série dos Lantanídeos/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Imagem Óptica , Nanopartículas/química
9.
Plant Physiol ; 188(2): 1061-1080, 2022 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-34747475

RESUMO

Infection cycles of viruses are highly dependent on membrane-associated host factors. To uncover the infection cycle of Bamboo mosaic virus (BaMV) in detail, we purified the membrane-associated viral complexes from infected Nicotiana benthamiana plants and analyzed the involved host factors. Four isoforms of voltage-dependent anion channel (VDAC) proteins on the outer membrane of mitochondria were identified due to their upregulated expression in the BaMV complex-enriched membranous fraction. Results from loss- and gain-of-function experiments indicated that NbVDAC2, -3, and -4 are essential for efficient BaMV accumulation. During BaMV infection, all NbVDACs concentrated into larger aggregates, which overlapped and trafficked with BaMV virions to the structure designated as the "dynamic BaMV-induced complex." Besides the endoplasmic reticulum and mitochondria, BaMV replicase and double-stranded RNAs were also found in this complex, suggesting the dynamic BaMV-induced complex is a replication complex. Yeast two-hybrid and pull-down assays confirmed that BaMV triple gene block protein 1 (TGBp1) could interact with NbVDACs. Confocal microscopy revealed that TGBp1 is sufficient to induce NbVDAC aggregates, which suggests that TGBp1 may play a pivotal role in the NbVDAC-virion complex. Collectively, these findings indicate that NbVDACs may associate with the dynamic BaMV-induced complex via TGBp1 and NbVDAC2, -3, or -4 and can promote BaMV accumulation. This study reveals the involvement of mitochondrial proteins in a viral complex and virus infection.


Assuntos
Proteínas de Membrana/metabolismo , Vírus do Mosaico/patogenicidade , Nicotiana/virologia , Doenças das Plantas/virologia , Potexvirus/patogenicidade , RNA Polimerase Dependente de RNA/metabolismo , Canais de Ânion Dependentes de Voltagem/metabolismo , Interações Hospedeiro-Parasita
10.
Environ Sci Technol ; 57(27): 10127-10134, 2023 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-37315045

RESUMO

Herein, we developed an electrochemical filtration system for effective and selective abatement of nitrogenous organic pollutants via peroxymonosulfate (PMS) activation. Highly conductive and porous copper nanowire (CuNW) networks were constructed to serve simultaneously as catalyst, electrode, and filtration media. In one demonstration of the CuNW network's capability, a single pass through a CuNW filter (τ < 2 s) degraded 94.8% of sulfamethoxazole (SMX) at an applied potential of -0.4 V vs SHE. The exposed {111} crystal plane of CuNW triggered atomic hydrogen (H*) generation on sites, which contributed to effective PMS reduction. Meanwhile, with the involvement of SMX, a Cu-N bond was formed by the interactions between the -NH2 group of SMX and the Cu sites of CuNW, accompanied by the redox cycling of Cu2+/Cu+, which was facilitated by the applied potential. The different charges of the active Cu sites made it easier to withdraw electrons and promote PMS oxidation. Theoretical calculations and experimental results were combined to suggest a mechanism for pollution abatement with CuNW networks. The results showed that system efficacy for the degradation of a wide array of nitrogenous pollutants was robust across a broad range of solution pH and complex aqueous matrices. The flow-through operation of the CuNW filter outperformed conventional batch electrochemistry due to convection-enhanced mass transport. This study provides a new strategy for environmental remediation by integrating state-of-the-art material science, advanced oxidation processes, and microfiltration technology.


Assuntos
Poluentes Ambientais , Nanofios , Poluentes Químicos da Água , Cobre , Nitrogênio , Poluentes Químicos da Água/análise , Peróxidos/química , Sulfametoxazol/química
11.
J Environ Sci (China) ; 127: 60-68, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36522089

RESUMO

With increasing concerns on the environment and human health, the degradation of glyphosate through the formation of less toxic intermediates is of great importance. Among the developed methods for the degradation of glyphosate, photodegradation is a clean and efficient strategy. In this work, we report a new photocatalyst by doping F ion on BiVO4 that can efficiently degrade glyphosate and reduce the toxic emissions of aminomethylphosphonic acid (AMPA) through the selective (P)-C-N cleavage in comparison of BiVO4 catalyst. The results demonstrate that the best suppression of AMPA formation was achieved by the catalyst of 0.3F@BiVO4 at pH = 9 (AMPA formation below 10%). In situ attenuated total reflectance Fourier transforms infrared (ATR-FTIR) spectroscopy indicates that the adsorption sites of glyphosate on BiVO4 and 0.3F@BiVO4 are altered due to the difference in electrostatic interactions. Such an absorption alteration leads to the preferential cleavage of the C-N bond on the N-C-P skeleton, thereby inhibiting the formation of toxic AMPA. These results improve our understanding of the photodegradation process of glyphosate catalyzed by BiVO4-based catalysts and pave a safe way for abiotic degradation of glyphosate.


Assuntos
Flúor , Glicina , Humanos , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico , Fotólise , Glifosato
12.
New Phytol ; 235(4): 1543-1557, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35524450

RESUMO

A gene upregulated in Nicotiana benthamiana after Bamboo mosaic virus (BaMV) infection was revealed as 1-deoxy-d-xylulose-5-phosphate reductoisomerase (NbDXR). DXR is the key enzyme in the 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway that catalyzes the conversion of 1-deoxy-d-xylulose 5-phosphate to 2-C-methyl-d-erythritol-4-phosphate. Knockdown and overexpression of NbDXR followed by BaMV inoculation revealed that NbDXR is involved in BaMV accumulation. Treating leaves with fosmidomycin, an inhibitor of DXR function, reduced BaMV accumulation. Subcellular localization confirmed that DXR is a chloroplast-localized protein by confocal microscopy. Furthermore, knockdown of 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate reductase, one of the enzymes in the MEP pathway, also reduced BaMV accumulation. The accumulation of BaMV increased significantly in protoplasts treated with isopentenyl pyrophosphate. Thus, the metabolites of the MEP pathway could be involved in BaMV infection. To identify the critical components involved in BaMV accumulation, we knocked down the crucial enzyme of isoprenoid synthesis, NbGGPPS11 or NbGGPPS2. Only NbGGPPS2 was involved in BaMV infection. The geranylgeranyl pyrophosphate (GGPP) synthesized by NbGGPPS2 is known for gibberellin synthesis. We confirmed this result by supplying gibberellic acid exogenously on leaves, which increased BaMV accumulation. The de novo synthesis of gibberellic acid could assist BaMV accumulation.


Assuntos
Giberelinas , Nicotiana/virologia , Potexvirus , Eritritol/análogos & derivados , Eritritol/biossíntese , Giberelinas/metabolismo , Potexvirus/fisiologia , Fosfatos Açúcares/biossíntese , Nicotiana/metabolismo
13.
Sensors (Basel) ; 22(4)2022 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-35214285

RESUMO

This paper proposes a novel unsupervised learning framework for depth recovery and camera ego-motion estimation from monocular video. The framework exploits the optical flow (OF) property to jointly train the depth and the ego-motion models. Unlike the existing unsupervised methods, our method extracts the features from the optical flow rather than from the raw RGB images, thereby enhancing unsupervised learning. In addition, we exploit the forward-backward consistency check of the optical flow to generate a mask of the invalid region in the image, and accordingly, eliminate the outlier regions such as occlusion regions and moving objects for the learning. Furthermore, in addition to using view synthesis as a supervised signal, we impose additional loss functions, including optical flow consistency loss and depth consistency loss, as additional supervision signals on the valid image region to further enhance the training of the models. Substantial experiments on multiple benchmark datasets demonstrate that our method outperforms other unsupervised methods.


Assuntos
Fluxo Óptico , Ego , Movimento (Física) , Aprendizado de Máquina não Supervisionado
14.
J Environ Manage ; 321: 115982, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36104886

RESUMO

Hydrodynamic cavitation has been a promising method and technology in wastewater treatment, while the principles based on the design of cavitational reactors to optimize cavitation yield and performance remains lacking. Computational fluid dynamics (CFD), a supplementation of experimental optimization, has become an essential tool for this issue, owing to the merits of low investment and operating costs. Nevertheless, researchers with a non-engineering background or few CFD fundamentals used straightforward numerical strategies to treat cavitating flows, and this might result in many misinterpretations and consequently poor computations. This review paper presents the rationale behind hydrodynamic cavitation and application of cavitation modeling specific to the reactors in wastewater treatment. In particular, the mathematical models of multiphase flow simulation, including turbulence closures and cavitation models, are comprehensively described, whilst the advantages and shortcomings of each model are also identified and discussed. Examples and methods of the coupling of CFD technology, with experimental observations to investigate into the hydrodynamic behavior of cavitating devices that feature linear and swirling flows, are also critically summarized. Modeling issues, which remain unaddressed, i.e., the implementation strategies of numerical models, and the definition of cavitation numbers are identified and discussed. Finally, the advantages of CFD modeling are discussed and the future of CFD applications in this research area is also outlined. It is expected that the present paper would provide decision-making support for CFD beginners to efficiently perform CFD modeling and promote the advancement of cavitation simulation of reactors in the field of wastewater treatment.


Assuntos
Hidrodinâmica , Purificação da Água , Simulação por Computador , Modelos Teóricos , Tecnologia
15.
Environ Geochem Health ; 44(8): 2615-2628, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34365569

RESUMO

Information on PAH distribution in the water level fluctuation zone (WLFZ) of Three Gorges Reservoir is limited. In this study, we investigated PAH distribution and sources and assessed PAH risks, over one annual water level fluctuation cycle (June 2017-June 2018) at four elevations spanning the WLFZ (145 m, 155 m, 165 m and 175 m) at seven locations in the water level fluctuation zone along Xiangxi River. The mean total PAH concentration in June 2018 (953 ng g-1) was significantly higher than in June 2017 (494 ng g-1), and the horizontal and vertical distributions of PAHs changed significantly. The changes in distribution patterns provided evidence for the cause of increased PAH levels, which were attributed to construction of the Xiangxi River Bridge. Thus, this study of PAH dynamics in the WLFZ soils of Xiangxi Bay also provided valuable information on the impact of bridge construction on WLFZ soils. The change in PAH levels among stations implicated sediment disturbance resulting from bridge construction as the major contributor to the increased PAH levels. Source characterization, based on the ratios of certain PAHs, indicates that PAHs are mainly from the combustion of petroleum fuels, biomass and coal. These ratios indicated that the proportion of PAHs from fuel combustion increased from 2017 to 2018, implicating the heavy equipment used during bridge construction as another source of the increased PAH levels. The incremental lifetime cancer risk (ILCR) model was used to assess the health risk of the PAHs and the range among all age groups (10-5-10-4) indicates a potential health risk. The mean effects range-median quotient (M-ERM-Q) was used to assess the ecological risk of PAHs and the range (0.1-0.5) indicates low to medium risk. The increase in PAH levels from 2017 to 2018 increased the risk to public health and the environment. The results of this investigation provide a reference for ecological restoration of the WLFZ and support development of effective policies for environmental and public health. Further, the results provide information on the impact of bridge construction on WLFZ soils and identify research needed to more fully understand PAH dynamics in WLFZ soils.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Baías , China , Monitoramento Ambiental/métodos , Sedimentos Geológicos , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Medição de Risco , Solo , Água , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
16.
Angew Chem Int Ed Engl ; 61(19): e202200413, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35166425

RESUMO

Synthesizing H2 O2 from water and air via a photocatalytic approach is ideal for efficient production of this chemical at small-scale. However, the poor activity and selectivity of the 2 e- water oxidation reaction (WOR) greatly restricts the efficiency of photocatalytic H2 O2 production. Herein we prepare a bipyridine-based covalent organic framework photocatalyst (denoted as COF-TfpBpy) for H2 O2 production from water and air. The solar-to-chemical conversion (SCC) efficiency at 298 K and 333 K is 0.57 % and 1.08 %, respectively, which are higher than the current reported highest value. The resulting H2 O2 solution is capable of degrading pollutants. A mechanistic study revealed that the excellent photocatalytic activity of COF-TfpBpy is due to the protonation of bipyridine monomer, which promotes the rate-determining reaction (2 e- WOR) and then enhances Yeager-type oxygen adsorption to accelerate 2 e- one-step oxygen reduction. This work demonstrates, for the first time, the COF-catalyzed photosynthesis of H2 O2 from water and air; and paves the way for wastewater treatment using photocatalytic H2 O2 solution.


Assuntos
Peróxido de Hidrogênio/síntese química , Estruturas Metalorgânicas , Oxigênio , Fotossíntese , Água
17.
Environ Geochem Health ; 43(2): 915-930, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32535759

RESUMO

Heavy metals (HMs) contamination in rivers has attracted wide concern due to its persistence and potential risks to the natural environment and human health. In this study, eight HMs (As, Hg, Cu, Pb, Ca, Zn, Mn, and Ni) were measured by inductively coupled plasma mass spectrometry in 24 water samples to investigate HMs contamination levels in the Xiangxi River of the Yangtze River basin. A geographic information systems kriging interpolation method was used to reveal the spatial distribution of HMs contamination. The results indicate that most HMs occurred at acceptable levels below the Surface Water Quality Standard (GB 3838-2002), with the highest concentration (23.23 mg kg-1) of Mn being observed at sampling site X20. The values of the potential ecological risk index (RI) suggest that high potential ecological risks were present at sampling sites X1, X3, X4, X14, X16, X17, and X24, which reached moderate risk level. The highest value of RI (279.56) was observed at site X17. HM spatial distributions show that upstream pollution is more severe than downstream. The hazard index was below 1 for all HMs except for Mn, indicating that HMs in Xiangxi River pose a low risk to human health. HM source identification was accomplished using principal component analysis and Pearson's correlation. Cu, Cd, Ni, and Hg originate primarily from agriculture, while Pb, Zn, and As originate primarily from transportation and mining. This research provides a reference on the risks posed by HMs in Xiangxi River and will support efforts to protect and improve water quality in Xiangxi River.


Assuntos
Metais Pesados/análise , Rios/química , Poluentes Químicos da Água/análise , Agricultura , China , Monitoramento Ambiental , Humanos , Mineração , Medição de Risco , Análise Espacial , Meios de Transporte
18.
J Environ Sci (China) ; 100: 203-215, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33279033

RESUMO

Photocatalytic process represents a promising approach to overcome the pollution challenge associated with the antibiotics-containing wastewater. This study provides a green, efficient and novel approach to remove cephalosporins, particularly cefoperazone sodium (CFP). Bi4O5Br2 was chosen for the first time to systematically study its degradation for CFP, including the analysis of material structure, degradation performance, the structure and toxicity of the transformation products, etc. The degradation rate results indicated that Bi4O5Br2 had an excellent catalytic activity leading to 78% CFP removal compared with the pure BiOBr (38%) within 120 min of visible light irradiation. In addition, the Bi4O5Br2 presents high stability and good organic carbon removal efficiency. The effects of the solution pH (3.12 - 8.75) on catalytic activity revealed that CFP was mainly photocatalyzed under acidic conditions and hydrolyzed under alkaline conditions. Combined with active species and degradation product identification, the photocatalytic degradation pathways of CFP by Bi4O5Br2 was proposed, including hydrolysis, oxidation, reduction and decarboxylation. Most importantly, the identified products were all hydrolysis rather than oxidation byproducts transformed from the intermediate of ß-lactam bond cleavage in CFP molecule, quite different from the mostly previous studies. Furthermore, the final products were demonstrated to be less toxic through the toxicity analysis. Overall, this study illustrates the detailed mechanism of CFP degradation by Bi4O5Br2 and confirms Bi4O5Br2 to be a promising material for the photodegradation of CFP.


Assuntos
Cefoperazona , Cefalosporinas , Catálise , Oxirredução , Fotólise
19.
J Exp Bot ; 71(22): 6932-6944, 2020 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-32926136

RESUMO

NbRabF1, a small GTPase from Nicotiana benthamiana and a homolog of Arabidopsis thaliana Ara6, plays a key role in regulating Bamboo mosaic virus (BaMV) movement by vesicle transport between endosomal membranes. Reducing the expression of NbRabF1 in N. benthamiana by virus-induced gene silencing decreased the accumulation of BaMV, and with smaller infection foci on inoculated leaves, but had no effect in protoplasts. Furthermore, transient expression of NbRabF1 increased the accumulation of BaMV in inoculated leaves. Thus, NbRabF1 may be involved in the cell-to-cell movement of BaMV. The potential acyl modification sites at the second and third amino acid positions of NbRabF1 were crucial for membrane targeting and BaMV accumulation. The localization of mutant forms of NbRabF1 with the GDP-bound (donor site) and GTP-bound (acceptor site) suggested that NbRabF1 might regulate vesicle trafficking between the Golgi apparatus and plasma membrane. Furthermore, GTPase activity could also be involved in BaMV cell-to-cell movement. Overall, in this study, we identified a small GTPase, NbRabF1, from N. benthamiana that interacts with its activation protein NbRabGAP1 and regulates vesicle transport from the Golgi apparatus to the plasma membrane. We suggest that the BaMV movement complex might move from cell to cell through this vesicle trafficking route.


Assuntos
Proteínas Monoméricas de Ligação ao GTP , Potexvirus , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Potexvirus/genética , Nicotiana/metabolismo
20.
Pediatr Cardiol ; 41(8): 1783-1794, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32939586

RESUMO

Idiopathic ventricular tachycardia (IVT) is the major cause of sudden cardiac death. Patients with IVT were usually manifested without structural heart disease. In this present study, we performed family-based whole genome sequencing (WGS) and Sanger sequencing for a 5-year-old Chinese boy with IVT and all the unaffected family members in order to identify the candidate gene and disease-causing mutation underlying the disease phenotype. Results showed that a novel heterozygous single-nucleotide duplication (c.128dup) and a novel heterozygous missense (c.3328A > G) variant in ABCA5 gene were identified in the proband. The single-nucleotide duplication (c.128dupT), inherited from his father and patrilineal grandfather, leads to a frameshift which results into the formation of a truncated ABCA5 protein of 50 (p.Leu43Phefs*8) amino acids. Hence, it is a loss-of-function mutation. The missense (c.3328A > G) variant, inherited from his mother, leads to the replacement of isoleucine by valine at the position of 1110 (p.Ile1110Val) of the ABCA5 protein. Multiple sequence alignment showed that p.Ile1110 is evolutionarily conserved among several species indicating both the structural and functional significance of the p.Ile1110 residue in the wild-type ABCA5 protein. Quantitative RT-PCR showed that the ABCA5 mRNA expression levels were decreased in the proband. These two novel variants of ABCA5 gene were co-segregated well among all the members of this family. Our present study also strongly supports the importance of using family-based whole genome sequencing for identifying novel candidate genes associated with IVT.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Taquicardia Ventricular/genética , Povo Asiático/genética , Pré-Escolar , Morte Súbita Cardíaca/epidemiologia , Heterozigoto , Humanos , Masculino , Mutação , Linhagem , Fenótipo , Sequenciamento Completo do Genoma
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