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1.
Insect Sci ; 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38706046

RESUMO

In insects, melanism, a fundamental pigmentation process, is of significant importance in evolutionary biology due to its complex genetic foundation. We investigated the role of the RNA-binding gene Musashi (msi) in melanism in Laodelphax striatellus, a Hemiptera species. We identified a single L. striatellus msi homolog, Lsmsi, encoding a 357 amino acid protein with 2 RNA recognition motifs. RNA interference-mediated knockdown of LsMsi resulted in complete body melanism and increased cuticular permeability. Additionally, we found the involvement of G protein-coupled receptor A42 and tyrosine hydroxylase (Th) in L. striatellus melanism. Knockdown of LsTh lightened the epidermis, showing dehydration signs, while LsA42 knockdown enhanced LsTh expression, leading to melanism. Surprisingly, Lsmsi knockdown decreased both LsA42 and LsTh expression, which was expected to cause whitening but resulted in melanism. Further, we found that Lsmsi influenced downstream genes like phenoloxidase homolog LsPo and dopa decarboxylase (Ddc) homolog LsDdc in the tyrosine-mediated melanism pathway. Extending to Nilaparvata lugens and Sogatella furcifera, we demonstrated the conserved role of msi in melanism among Delphacidae. Given MSI proteins' roles in cancer and tumors in vertebrates, our study is the first to link msi in insects to Delphacidae body color melanization via the tyrosine-mediated pathway, offering fresh perspectives on the genetic basis of insect melanism and msi functions.

2.
Insects ; 15(4)2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38667392

RESUMO

The fruitless (fru) gene functions as a crucial "tuner" in male insect courtship behavior through distinct expression patterns. In Nilaparvata lugens, our previous research showed doublesex (dsx) influencing male courtship songs, causing mating failures with virgin females. However, the impact of fru on N. lugens mating remains unexplored. In this study, the fru homolog (Nlfru) in N. lugens yielded four spliceosomes: Nlfru-374-a/b, Nlfru-377, and Nlfru-433, encoding proteins of 374aa, 377aa, and 433aa, respectively. Notably, only Nlfru-374b exhibited male bias, while the others were non-sex-specific. All NlFRU proteins featured the BTB conserved domain, with NlFRU-374 and NlFRU-377 possessing the ZnF domain with different sequences. RNAi-mediated Nlfru or its isoforms' knockdown in nymph stages blocked wing-flapping behavior in mating males, while embryonic knockdown via maternal RNAi resulted in over 80% of males losing wing-flapping ability, and female receptivity was reduced. Nlfru expression was Nldsx-regulated, and yet courtship signals and mating success were unaffected. Remarkably, RNAi-mediated Nlfru knockdown up-regulated the expression of flightin in macropterous males, which regulated muscle stiffness and delayed force response, suggesting Nlfru's involvement in muscle development regulation. Collectively, our results indicate that Nlfru functions in N. lugens exhibit a combination of conservation and species specificity, contributing insights into fru evolution, particularly in Hemiptera species.

3.
Pest Manag Sci ; 80(3): 1240-1248, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37934463

RESUMO

BACKGROUND: Homing-based gene drives targeting sex-specific lethal genes have been used for genetic control. Additionally, understanding insect sex determination provides new targets for managing insect pests. While sex determination mechanisms in holometabolous insects have been thoroughly studied and employed in pest control, the study of the sex determination pathway in hemimetabolous insects is limited to only a few species. Riptortus pedestris (Fabricius; Hemiptera: Heteroptera), commonly known as the bean bug, is a significant pest for soybeans. Nonetheless, the mechanism of its sex determination and the target gene for genetic control are not well understood. RESULTS: We identified Rpfmd as the female determiner gene in the sex determination pathway of R. pedestris. Rpfmd encodes a female-specific serine/arginine-rich protein of 436 amino acids and one non-sex-specific short protein of 98 amino acids. Knockdown of Rpfmd in R. pedestris nymphs caused death of molting females with masculinized somatic morphology but did not affect male development. Knockdown of Rpfmd in newly emerged females inhibited ovary development, while maternal-mediated RNA interference (RNAi) knockdown of Rpfmd expression resulted in male-only offspring. Transcriptome sequencing revealed that Rpfmd regulates X chromosome dosage compensation and influences various biological processes in females but has no significant effect on males. Moreover, RNAi mediated knockdown of Rpfmd-C had no influence on the development of R. pedestris, suggesting that Rpfmd regulates sex determination through female-specific splicing isoforms. We also found that Rpfmd pre-mRNA alternative splicing regulation starts at the 24-h embryo stage, indicating the activation of sex differentiation. CONCLUSION: Our study confirms that Rpfmd, particularly its female-specific isoform (Rpfmd-F), is the female determiner gene that regulates sex differentiation in R. pedestris. Knockdown of Rpfmd results in female-specific lethality without affecting males, making it a promising target for genetic control of this soybean pest throughout its development stages. Additionally, our findings improve the understanding of the sex-determination mechanism in hemimetabolous insects. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Heterópteros , Masculino , Feminino , Animais , Heterópteros/fisiologia , Glycine max , Regulação da Expressão Gênica , Aminoácidos/metabolismo
4.
Insects ; 14(11)2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37999033

RESUMO

In most holometabolous insects, transformer-2 (tra-2) is an auxiliary gene required for sex determination, exerting a crucial role in regulating sexual differentiation; however, the study of tra-2 in hemimetabolous insects remains very sparse and limited to just a few species. In this study, we investigated the sequence and expression profile of the tra-2 gene in the bean bug, Riptortus pedestris, an agricultural pest belonging to the Heteroptera order. Three non-sex-specific splicing isoforms of Rptra-2 were found, Rptra-2293, Rptra-2284, and Rptra-2299, which shared most exons and exhibited similar expression throughout all stages of development, with particularly elevated levels in the embryo, ovary, and testis. RNAi knockdown experiments revealed that the suppression of Rptra-2 in nymphs led to abnormal females, characterized the formation of male-specific external genital, and also caused longer nymph duration. Knockdown of the expression of the Rptra-2 gene in newly emergent virgin females would cause ovarian arrest, and injecting the 8th-day virgin females with dsRptra-2 also caused a noticeable decline in the offspring numbers. Conversely, in dsRptra-2-treated males, the testes maintained normal morphology but experienced impaired reproductive capacity, attributed to diminished sperm viability. These findings highlight the crucial role of Rptra-2 in the sex determination and fertility of R. pedestris, providing valuable insights into the sex determination mechanisms of hemimetabolous insects.

5.
Chemosphere ; 331: 138796, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37142103

RESUMO

Iron-modified biochar (Fe-biochar) has been widely developed to attenuate Cr(VI) pollution in both acid and alkaline environments. However, there are few comprehensive studies on how the iron speciation in Fe-biochar and chromium speciation in solution influencing the removal of Cr(VI) and Cr(III) under varying pH. Here, multiple Fe-biochar containing Fe3O4 or Fe(0) were prepared and applied to remove aqueous Cr(VI). Kinetics and isotherms suggested that all Fe-biochar could efficiently remove Cr(VI) and Cr(III) via adsorption-reduction-adsorption. The Fe3O4-biochar immobilized Cr(III) by forming FeCr2O4, while amorphous Fe-Cr coprecipitate and Cr(OH)3 was formed when using Fe(0)-biochar. Density functional theory (DFT) analysis further indicated that pH increase caused more negative adsorption energies between Fe(0)-biochar and the pH-dependent Cr(VI)/Cr(III) species. Consequently, the adsorption and immobilization of Cr(VI) and Cr(III) species by Fe(0)-biochar was more favored at higher pH. In comparison, Fe3O4-biochar exhibited weaker adsorption abilities for Cr(VI) and Cr(III), which were in consistent with their less negative adsorption energies. Nonetheless, Fe(0)-biochar merely reduced ∼70% of adsorbed Cr(VI), while ∼90% of adsorbed Cr(VI) was reduced by Fe3O4-biochar. These results unveiled the importance of iron and chromium speciation for chromium removal under varying pH, and might guide the application-oriented design of multifunctional Fe-biochar for broad environmental remediation.


Assuntos
Cromo , Ferro , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Cromo/análise , Concentração de Íons de Hidrogênio , Poluentes Químicos da Água/análise
6.
Chemosphere ; 327: 138505, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36965535

RESUMO

The complete pathway of chromium (Cr) transfer from soil to plant tissues and subcellular components under biochar amendment remains to be quantified, as well as the involved diverse detoxification processes in roots and stems respectively. Pot experiments and quantitative analysis were conducted to investigate Cr fixation in soil amended with Enteromorpha prolifera-derived biochar and subsequent phytoprocesses (Cr uptake, transfer, and phytotoxicity) in cultivated Secale cereale L. (rye). The results indicated that adding 5-30 g kg-1 of biochar increased the residual form of Cr (B4) in soil by 8-21% and decreased the bioavailable form of Cr (B1) by 9-29%. For Cr transferred to rye, Cr in the rye was mainly present in the low-toxicity bound state, with the acetic acid-extracted Cr (F4) (45-54%) in roots and the NaCl-extracted Cr (F3) (37-47%) in stems. The subcellular distribution of Cr in both roots and stems was predominantly in the cell wall and residues (T1), followed by the cytoplasm (T4). Partial least squares path model (PLS-PM) was used for quantifying the effect of biochar on the form changes and subcellular detoxification of Cr from soil to roots and stems to sub-cells. In soils, biochar reduced the bioavailability of Cr and decreased the transfer of Cr to rye. In plant roots, Cr was distributed mainly as low-toxicity phosphate complexes in cell walls and vacuoles in sub-cells (with the largest path coefficients of 0.90 and -0.91, respectively). In the stems, Cr was distributed mainly as proteins integrated into the cell walls and vacuoles. This was due to the difference in subcellular compartmentalization of detoxification in the roots and stems. These PLS-PM results provide new insights into the entire process of pollutant detoxification in complex environments.


Assuntos
Cromo , Poluentes do Solo , Cromo/química , Solo/química , Poluentes do Solo/análise , Carvão Vegetal/química , Plantas/metabolismo
8.
Appl Opt ; 61(21): 6177-6185, 2022 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-36256230

RESUMO

Bacteria, especially foodborne pathogens, seriously threaten human life and health. Rapid discrimination techniques for foodborne pathogens are still urgently needed. At present, laser-induced breakdown spectroscopy (LIBS), combined with machine learning algorithms, is seen as fast recognition technology for pathogenic bacteria. However, there is still a lack of research on evaluating the differences between different bacterial classification models. In this work, five species of foodborne pathogens were analyzed via LIBS; then, the preprocessing effect of five filtering methods was compared to improve accuracy. The preprocessed spectral data were further analyzed with a support vector machine (SVM), a backpropagation neural network (BP), and k-nearest neighbor (KNN). Upon comparing the capacity of the three algorithms to classify pathogenic bacteria, the most suitable one was selected. The signal-to-noise ratio and mean square error of the spectral data after applying a Savitzky-Golay filter reached 17.4540 and 0.0020, respectively. The SVM algorithm, BP algorithm, and KNN algorithm attained the highest classification accuracy for pathogenic bacteria, reaching 98%, 97%, and 96%, respectively. The results indicate that, with the support of a machine learning algorithm, LIBS technology demonstrates superior performance, and the combination of the two is expected to be a powerful tool for pathogen classification.


Assuntos
Algoritmos , Aprendizado de Máquina , Humanos , Análise Espectral/métodos , Máquina de Vetores de Suporte , Bactérias
9.
Perit Dial Int ; 42(6): 585-590, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35993242

RESUMO

BACKGROUND: Metagenomic next-generation sequencing (mNGS) can improve pathogen identification in infectious diseases. METHODS: A prospective parallel control study was undertaken to evaluate the clinical significance of mNGS in identifying pathogens in dialysis effluent of patients with peritoneal dialysis-associated peritonitis (peritonitis). Dialysis effluent specimens were detected both by peritoneal dialysis effluent culture and mNGS. The positive rates and coincidence rates of the two methods were compared. RESULTS: From April 2020 to March 2021, 30 patients presenting with peritonitis were enrolled in this study. The positive pathogen detection rate of mNGS was significantly higher than that of the traditional culture method (86.67% vs. 60.00%; p = 0.039). Fifteen specimens were positive for both of the methods, while 11 specimens were negative for culture but positive for mNGS. Three specimens were positive for culture but negative for mNGS; all of them were streptococcus mitis. One specimen was negative for both methods. The culture method detected one type of pathogen in all specimens; however, two or more types of pathogens were detected in eight specimens by mNGS. In addition to common pathogens, additional pathogens detected by mNGS included Coxiella burnetii, human herpesvirus type 5, human herpesvirus type 6B and Mortierella. CONCLUSION: The pathogen detection rate of mNGS in dialysis effluent of peritonitis patients was significantly higher than that of traditional culture. The mNGS is advantageous in diagnosing the pathogens that are difficult to be cultured. However, mNGS did not demonstrate sensitivity to streptococcus mitis. Results from this study show that mNGS, combined with traditional culture, has potential application for detecting pathogens in peritoneal dialysis patients with peritonitis.


Assuntos
Diálise Peritoneal , Peritonite , Humanos , Estudos Prospectivos , Sensibilidade e Especificidade , Diálise Peritoneal/efeitos adversos , Diálise Renal , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Peritonite/diagnóstico , Peritonite/etiologia
10.
Environ Pollut ; 310: 119874, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35931385

RESUMO

Generally, Zn in stormwater runoff is considered as low toxicity, but in the senarios of roads and zinc-based materials roof runoff, the concentration of Zn becomes extremely high and cannot be ignored. Bioretention systems are used to remove heavy metals from stormwater runoff, while Zn adsorption is insufficient by conventional filler and is prone to secondary release when exposed to acid rain or high salinity runoff. This study integrated batch experiments and density functional theory calculation to investigate the mechanisms of how KOH-modified biochar (KBC) influences the removal and release of Zn in bioretention systems. The results revealed that KBC adsorbed 89.0-97.5% Zn in the influent, the main adsorption mechanism were complexation and precipitation, and precipitation is more important. In addition, 67% of Zn was immoblized as the residual form by KBC. In acidic and saline runoff, KBC reduced Zn secondary release by 43.6% and 37.08% compared to the results in the absence of KBC, which was attributed to the convertion of most dissolved Zn in acidic and saline runoff into residual Zn. Therefore, KBC has a considerable application potential not only to decontaminate the runoff of roads and Zn-containing roofs, but also to deal with secondary Zn release in acid rain or under the treatment of snow-melting agents.


Assuntos
Chuva Ácida , Álcalis , Adsorção , Carvão Vegetal , Zinco
11.
J Environ Manage ; 316: 115200, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35533595

RESUMO

Biochar and plant cooperation in remediation of heavy metal contaminated soil is effective and important, but there still have knowledge gaps of synergistic effect between the two and the synergistic pathway has not been clarified. We prepared the Enteromorpha prolifera biochar at 400 °C and 600 °C (denoted as BC400 and BC600). The Pb fractions changes in soil and Pb toxicity in Brassica juncea were investigated by adding 30 g kg-1 biochar to soil containing 1200 mg kg-1 Pb in a pot experiment. There was a significant synergistic effect between biochar and plants on Pb immobilization in soil, according to the "E > 0" of Pb fractions in the interaction equation. Pb immobilization rates of biochar-plant treatments (BJBC4 and BJBC6) were 12.47% and 11.38% higher than biochar treatment (BC4, BC6), and 17.66% and 16.28% plant treatment (BJ). BJBC4 had a better immobilization effect than BJBC6. Biochar alleviated the phytotoxicity of Pb by increasing the antioxidant enzymes activities of plants. These results indicated two synergistic pathways: (1) The high pH and oxygen-containing functional groups of biochar could immobilize Pb through ion exchange, precipitation, or complexation. (2) Biochar enhanced the activity of the antioxidant enzyme system in plants thus improving the Pb tolerance of plants. Statistical analysis methods such as the partial least squares path modeling (PLS-PM) also confirmed the pathways. In a word, clear synergistic effects and pathways could guide the application of biochar and plants in Pb-contaminated soil.


Assuntos
Poluentes do Solo , Antioxidantes , Carvão Vegetal , Chumbo , Plantas , Solo , Poluentes do Solo/análise
12.
Micromachines (Basel) ; 13(3)2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35334746

RESUMO

In this work, we propose a novel way to flexibly engineer the waveguide dispersion by patterning the cladding of waveguide microresonators. Experimentally, we demonstrate silicon nitride waveguides with air-, oxide-, and SU-8 polymer-cladding layers and compare the corresponding waveguide dispersion. By integrating SU-8 polymer as the outer cladding layer, the waveguide dispersion can be tuned from -143 to -257 ps/nm/km. Through the simple, conventional polymer stripping process, we reconstruct the waveguide dispersion back to that of the original air-cladded device without significantly impacting the quality factor of resonators. This work provides the potential to design the waveguide dispersion in normal and anomalous regimes within an integrated photonic circuit.

13.
Sci Total Environ ; 826: 153905, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35189220

RESUMO

Remediation of Cr-contaminated soils with biochar is an effective method, but its effect on plant detoxification has not been clarified, and the translocation pathways of different chemical forms of Cr in the soil-plant system have not been quantitatively evaluated. This study investigated the effects of magnetically modified Enteromorpha prolifera biochar (FBC) on Cr uptake, translocation and phytotoxicity in the soil and barley (Hordeum vulgare L.). When the FBC dosage increased to 30 g·kg-1, the content of bioavailable Cr in the soil decreased by 56.82%. Additionally, the contents of Cr in H. vulgare decreased by 53.22%, and growth recovered to the normal level. Partial least squares path modelling (PLS-PM) was applied to establish two influence paths to explain how FBC impacted the whole system of soil and plants upon Cr exposure. The phytotoxic effect path of Cr suggested that FBC decreased the contents of Cr in soil and H. vulgare and then recovered growth by alleviating oxidative stress (ß = -0.45) and promoting chlorophyll synthesis (ß = 0.53) in shoots. The translocation and conversion path of Cr further indicated that Cr in the shoots was converted into low-migration forms and mainly trapped in cell walls and vacuoles rather than in organelles, consequently decreasing the phytotoxicity of Cr (ß = -0.73). These two soil-plant paths offer new insights into the application of biochar and plants in Cr-contaminated soils.


Assuntos
Hordeum , Poluentes do Solo , Carvão Vegetal/química , Cromo/análise , Hordeum/metabolismo , Plantas/metabolismo , Solo/química , Poluentes do Solo/análise
14.
Anal Chem ; 94(7): 3158-3164, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35129946

RESUMO

With cancer seriously hampering the increasing life expectancy of people, developing an instant diagnostic method has become an urgent objective. In this work, we developed a label-free laser-induced breakdown spectroscopy (LIBS) method for high-throughput recognition of tumor cells. LIBS spectra were straightly collected from cells dropped on a silicon substrate and built into a deep learning model for simultaneous classification of various cancers. To interpret the result of the deep learning algorithm, gradient-weighted class activation mapping was utilized to a one-dimensional convolution neural network (1D-CNN), and the saliency maps thus obtained amplified the differences between the spectra of cell lines. Overall results showed that the 1D-CNN algorithms achieved a mean sensitivity of 94.00%, a mean specificity of 98.47%, and a mean accuracy of 97.56%. Thus, the proposed method performed satisfactorily and is seen as an interpretable classification process for cancer cell lines.


Assuntos
Aprendizado Profundo , Algoritmos , Contagem de Células , Humanos , Redes Neurais de Computação , Análise Espectral
15.
BMC Nephrol ; 22(1): 322, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34579654

RESUMO

BACKGROUND: Chronic kidney disease (CKD) is a common health challenge. There are some risk models predicting CKD adverse outcomes, but seldom focus on the Mongoloid population in East Asian. So, we developed a simple but intuitive nomogram model to predict 3-year CKD adverse outcomes for East Asian patients with CKD. METHODS: The development and internal validation of prediction models used data from the CKD-ROUTE study in Japan, while the external validation set used data collected at the First People's Hospital of Foshan in southern China from January 2013 to December 2018. Models were developed using the cox proportional hazards model and nomogram with SPSS and R software. Finally, the model discrimination, calibration and clinical value were tested by R software. RESULTS: The development and internal validation data-sets included 797 patients (191 with progression [23.96%]) and 341 patients (89 with progression [26.10%]), respectively, while 297 patients (108 with progression [36.36%]) were included in the external validation data set. The nomogram model was developed with age, eGFR, haemoglobin, blood albumin and dipstick proteinuria to predict three-year adverse-outcome-free probability. The C-statistics of this nomogram were 0.90(95% CI, 0.89-0.92) for the development data set, 0.91(95% CI, 0.89-0.94) for the internal validation data set and 0.83(95% CI, 0.78-0.88) for the external validation data-set. The calibration and decision curve analyses were good in this model. CONCLUSION: This visualized predictive nomogram model could accurately predict CKD three-year adverse outcomes for East Asian patients with CKD, providing an easy-to-use and widely applicable tool for clinical practitioners.


Assuntos
Nomogramas , Insuficiência Renal Crônica/complicações , Idoso , Conjuntos de Dados como Assunto , Progressão da Doença , Ásia Oriental , Feminino , Humanos , Masculino , Prognóstico , Insuficiência Renal Crônica/etnologia , Insuficiência Renal Crônica/mortalidade
16.
Environ Pollut ; 287: 117641, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34426384

RESUMO

Salinity is a limiting factor in the growth of plants in coastal wetlands. The interaction of halophytes with salt-tolerant endophytes has been one of the major concerns in this area. However, the mechanism by which endophytes promote halophyte growth remains unclear. The growth and physiological responses of Suaeda salsa inoculated with endophytic bacteria (Sphingomonas prati and Sphingomonas zeicaulis) at 0 ‰ and 20 ‰ NaCl were studied. The results showed that Sphingomonas zeicaulis had stronger positive effects on the growth of Suaeda salsa under 0 ‰ NaCl, and Sphingomonas prati performed better under 20 ‰ NaCl. Sphingomonas prati inoculation increased the mean height, root length, fresh weight and dry weight by 45.43%, 9.91%, 82.00% and 102.25%, respectively, compared with the uninoculated treatment at 20 ‰ NaCl. Sphingomonas prati inoculation decreased MDA content by 23.78%, while the soluble sugar and soluble protein contents increased by 15.08% and 12.57%, respectively, compared to the control, at 20 ‰ NaCl. Increases in SOD and CAT in the Sphingomonas prati inoculation were 1.03 and 1.47-fold greater, respectively, than in the Sphingomonas zeicaulis inoculation, under 20 ‰ NaCl. Moreover, Sphingomonas prati and Sphingomonas zeicaulis had antagonistic interactions in Suaeda salsa according to the results of the "interaction equation" (most G values were negative). PCA, clustering analysis and the PLS model revealed two mechanisms for regulating plant salt tolerance by which Sphingomonas prati enhanced Suaeda salsa growth: (1) Sphingomonas prati improved intracellular osmotic metabolism and (2) Sphingomonas prati promoted the production of CAT in the antioxidant enzyme system and retained permeability. This study provides new insight into the comprehensive understanding and evaluation of endophytic bacteria as biological inoculants in plants under salt stress.


Assuntos
Chenopodiaceae , Tolerância ao Sal , Bactérias , Plantas Tolerantes a Sal , Sphingomonas , Áreas Alagadas
17.
Chem Commun (Camb) ; 57(59): 7312-7315, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34223591

RESUMO

This study proposes steganography based on laser-induced breakdown spectroscopy (LIBS) for the first time. LIBS inks containing different elements in varying concentrations were fabricated to write steganographic text. LIBS was combined with machine learning as an ideal tool to efficiently extract hidden information. The proposed steganography strategy has the advantages of low cost, high security, and good stability, thus providing a practical tool for information transfer.

18.
Front Microbiol ; 12: 641913, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33841363

RESUMO

Microorganisms are applied to remediate chromium (Cr)-contaminated soil extensively. Nevertheless, the microbial loss and growth inhibition in the soil environment restrain the application of this technology. In this study, a Cr(VI)-reducing strain named Bacillus cereus WHX-1 was screened, and the microbial aggregates system was established via immobilizing the strain on Enteromorpha prolifera biochar to enhance the Cr(VI)-reducing activity of this strain. The mechanism of the system on Cr(VI) transformation in Cr-contaminated soil was illuminated. Pot experiments indicated that the microbial aggregates system improved the physicochemical characteristics of Cr-contaminated soil obviously by increasing organic carbon content and cation exchange capacity, as well as decreasing redox potential and bulk density of soil. Moreover, 94.22% of Cr(VI) was transformed into Cr(III) in the pot, and the content of residue fraction Cr increased by 63.38% compared with control check (CK). Correspondingly, the physiological property of Ryegrass planted on the Cr-contaminated soil was improved markedly and the main Cr(VI)-reducing microbes, Bacillus spp., were enriched in the soil with a relative abundance of 28.43% in the microbial aggregates system. Considering more active sites of biochar for microbial aggregation, it was inferred that B. cereus WHX-1 could be immobilized by E. prolifera biochar, and more Cr(VI) was transformed into residue fraction. Cr stress was decreased and the growth of plants was enhanced. This study would provide a new perspective for Cr-contaminated soil remediation.

19.
Sci Total Environ ; 783: 146999, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-33865126

RESUMO

Carbon tetrachloride (CT) is highly toxic and recalcitrant in groundwater. In recent years, zero-valent aluminum (ZVAl) is highly reductive but limited by its surface passivation film. One of the effective ways to overcome this bottleneck is to add ligands. In this paper, compared with several other ligands, sodium citrate (SC), a natural organic ligand, was introduced to enhance microscale ZVAl (mZVAl) reactivity for the reductive degradation of CT. The results showed that the SC system could effectively reduce but not completely dechlorinate CT and electron utilization efficiency was as high as 94%. However, without ligands, mZVAl is chemically inert for CT degradation. Through SEM-EDS, BET, XRD, and XPS characterizations and H2 evolution experiments, enhanced mZVAl surface corrosion at the solid-liquid interface of mZVAl/SC system was verified. SC participated in the complexation corrosion reaction with surface inert film to form Al[Cit] complex, which made internal Al0 active sites exposed and then promoted mZVAl corrosion. In the five consecutive reuse experiments of mZVAl, CT can be completely degraded, which indicates that mZVAl, with the help of SC, has excellent sustainable utilization efficiency.

20.
Huan Jing Ke Xue ; 42(1): 274-282, 2021 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-33372479

RESUMO

In order to study the performance and mechanisms of bioretention pond media (Enteromorpha prolifera biochar) for NH4+-N removal in rainfall runoff, three kinds of alkali modified biochars (marked as BC1, BC2, and BC3) were prepared with various concentrations of NaOH solution (1, 2, and 3 mol·L-1) to explore their adsorption performance for NH4+-N. The results showed that:① Appropriate modifications of the NaOH concentration increased the specific surface area and surface microstructure of biochar, with the content of O and the surface functional groups being enriched. In addition, BC2 possessed the best adsorption performance. ② The adsorption capacity reached a maximum when the pH was 9.0 and the dosage of biochar was 0.5 g·L-1. Compared with BC, the adsorption capacity of BC1 and BC2 increased by 6.4% and 10.8%, respectively, while BC3 decreased by 13.7%. Moreover, BC2 had an optimal adsorption efficiency with a saturated adsorption capacity of 16.76mg·g-1. ③ The adsorption mechanism of biochar belonged to chemical adsorption with a monomolecular layer. The adsorption process was promoted by the high pH of biochar, the electrostatic attraction of biochar pores, the complexation and oxidization of the functional groups of hydroxyl (-OH), carboxyl (-COOH), and carbon-oxygen single bond (C-O). To sum up, the proper amount of NaOH to modify biochar can improve the adsorption performance of NH4+-N, and the modified biochar can be used as media of the bioretention pond to remove NH4+-N.


Assuntos
Amônia , Carvão Vegetal , Adsorção , Nitrogênio
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