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1.
Inorg Chem ; 63(17): 7714-7724, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38630017

RESUMO

Modulating the band gap of two-dimensional (2D) transition metal dichalcogenide (TMDC) semiconductors is critical for their application in a wider spectral range. Alloying has been demonstrated as an effective method for regulating the band gap of 2D TMDC semiconductors. The fabrication of large-area 2D TMDC alloy films with centimeter-scale uniformity is fundamental to the application of integrated devices. Herein, we report a liquid-phase precursor one-step chemical vapor deposition (CVD) method for fabricating a MoxW1-xS2 alloy monolayer with a large size and an adjustable band gap. Good crystalline quality and high uniformity on a wafer scale enable the continuous adjustment of its band gap in the range of 1.8-2.0 eV. Density functional theory calculations provided a deep understanding of the Raman-active vibration modes of the MoxW1-xS2 alloy monolayer and the change in the conductivity of the alloy with photon energy. The synthesis of large-area MoxW1-xS2 alloy monolayers is a critical step toward the application of 2D layered semiconductors in practical optoelectronic devices.

2.
Phys Chem Chem Phys ; 26(5): 3880-3889, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38226853

RESUMO

The development of efficient electrocatalysts for the hydrogen evolution reaction (HER) holds immense importance in the context of large-scale hydrogen production from water. Nevertheless, the practical application of such catalysts still relies on precious platinum-based materials. There is a pressing need to design high-performing, non-precious metal electrocatalysts capable of generating hydrogen at substantial current levels. We report here a stable monolith catalyst of Te-doped-WSe2 directly supported by a highly conductive W mesh. This catalyst demonstrates outstanding electrocatalytic performance and stability in acidic electrolytes, especially under high current conditions, surpassing the capabilities of commercial 5% Pt/C catalysts. Specifically, at current densities of 10 and 1200 mA cm-2, it exhibits a minimal overpotential of 79 and 232 mV, along with a small Tafel slope of 55 mV dec-1, respectively. The remarkable catalytic activity of Te-WSe2 can be attributed to the exceptional electron transfer facilitated by the stable monolithic structure, as well as the abundant and efficient active sites in the material. In addition, density functional theory calculations further indicate that Te doping adjusts H atom adsorption on various positions of WSe2, making it closer to thermal neutrality compared to the original material. This study presents an innovative approach to develop cost-effective HER electrocatalysts that perform optimally under high current density conditions.

3.
Nano Lett ; 22(8): 3465-3472, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35435694

RESUMO

HgTe colloidal quantum dots (CQDs) are promising absorber systems for infrared detection due to their widely tunable photoresponse in all infrared regions. Up to now, the best-performing HgTe CQD photodetectors have relied on using aggregated CQDs, limiting the device design, uniformity and performance. Herein, we report a ligand-engineered approach that produces well-separated HgTe CQDs. The present strategy first employs strong-binding alkyl thioalcohol ligands to enable the synthesis of well-dispersed HgTe cores, followed by a second growth process and a final postligand modification step enhancing their colloidal stability. We demonstrate highly monodisperse HgTe CQDs in a wide size range, from 4.2 to 15.0 nm with sharp excitonic absorption fully covering short- and midwave infrared regions, together with a record electron mobility of up to 18.4 cm2 V-1 s-1. The photodetectors show a room-temperature detectivity of 3.9 × 1011 jones at a 1.7 µm cutoff absorption edge.

4.
Small ; 18(48): e2205356, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36251788

RESUMO

Lead selenide (PbSe) colloidal quantum dots (CQDs) are promising candidates for optoelectronic applications. To date, PbSe CQDs capped by halide ligands exhibit improved stability and solar cells using these CQDs as active layers have reported a remarkable power conversion efficiency (PCE) up to 10%. However, PbSe CQDs are more prone to oxidation, requiring delicate control over their processability and compromising their applications. Herein, an efficient strategy that addresses this issue by an in situ cation-exchange process is reported. This is achieved by a two-phase ligand exchange process where PbI2 serves as both a passivating ligand and cation-source inducing transformation of CdSe to PbSe. The defect density and carrier lifetime of PbSe CQD films are improved to 1.05 × 1016  cm-3 and 12.2 ns, whereas the traditional PbSe CQD films possess 1.9 × 1016  cm-3 defect density and 10.2 ns carrier lifetime. These improvements are translated into an enhancement of photovoltaic performance of PbSe solar cells, with a PCE of up to 11.6%, ≈10% higher than the previous record. Notably, the approach enables greatly improved stability and a two-month stability is successfully demonstrated. This strategy is expected to promote the fast development of PbSe CQD applications in low-cost and high-performance optoelectronic devices.

5.
Brief Bioinform ; 21(1): 135-143, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-30445438

RESUMO

Circular RNA (circRNA) is a kind of covalently closed single-stranded RNA molecules that have been proved to play important roles in transcriptional regulation of genes in diverse species. With the rapid development of bioinformatics tools, a huge number (95143) of circRNAs have been identified from different plant species, providing an opportunity for uncovering the overall characteristics of plant circRNAs. Here, based on publicly available circRNAs, we comprehensively analyzed characteristics of plant circRNAs with the help of various bioinformatics tools as well as in-house scripts and workflows, including the percentage of coding genes generating circRNAs, the frequency of alternative splicing events of circRNAs, the non-canonical splicing signals of circRNAs and the networks involving circRNAs, miRNAs and mRNAs. All this information has been integrated into an upgraded online database, PlantcircBase 3.0 (http://ibi.zju.edu.cn/plantcircbase/). In this database, we provided browse, search and visualization tools as well as a web-based blast tool, BLASTcirc, for prediction of circRNAs from query sequences based on searching against plant genomes and transcriptomes.

6.
Phys Chem Chem Phys ; 24(2): 966-974, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34914818

RESUMO

SnS2 with atomic thickness has attracted extensive attention in the field of photocatalysis due to its special physicochemical properties, suitable band gap, low cost and low environmental toxicity. However, the application of SnS2 in the field of optoelectronics is restricted by its low photocatalytic efficiency and carrier mobility. In this study, vacancies and transition metal atoms are introduced into a SnS2 monolayer to modulate its physicochemical properties. Meanwhile, the SnS2 monolayer modified by vacancies and transition metal atoms is combined with graphene to form a heterostructure, which promotes the separation of photogenerated electron-hole pairs. The results of theoretical calculations show that the SnS2/graphene heterojunction can promote the separation of photogenerated carriers in intrinsic monolayer SnS2, and improve the photocatalytic efficiency and carrier mobility. The modification of Sn vacancies and Fe, Co atoms not only expands the visible light response range of the SnS2/graphene heterojunction, but also introduces magnetism, which is expected to be applied in spin optoelectronic materials. In this work, defects, doping and heterojunction assembly are rationally integrated, which provides a new idea for the design and development of spin optoelectronic devices based on monolayer SnS2.

7.
Int Orthop ; 45(12): 3091-3100, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34191090

RESUMO

STUDY DESIGN: Prospective study. PURPOSE: The main purpose of this study was to investigate whether the use of a tourniquet changes the blood coagulation state following primary total knee arthroplasty (TKA) by means of conventional coagulation tests and thromboelastography (TEG) analyses. METHODS: A total of 154 patients who underwent primary unilateral TKA from January 2018 to October 2020 were enrolled. Seventy-nine patients were randomized into a tourniquet group, and 75 were randomized into a no-tourniquet group. Demographic data, surgical time, intra-operative blood loss, transfusion rate, and wound complications were collected. Complete blood count, conventional coagulation tests, and TEG were performed the day before surgery, one day after surgery, three days after surgery, and seven days after surgery. Lower extremity Doppler ultrasound was performed the day before surgery and seven days after surgery. RESULTS: The baseline characteristics of the patients were similar between the two groups. Hidden blood loss, transfusion rate, and wound complications were similar between the two groups, but the intra-operative blood loss of the tourniquet group was lower than that of the no-tourniquet group. The calculated total blood loss of the tourniquet group was higher than that of the no-tourniquet group. In terms of conventional coagulation tests and TEG, the tourniquet group had higher values of fibrin degradation products, D-dimer, maximum amplitude, and coagulation index (p < 0.001). The incidence of deep vein thrombosis (DVT) in the tourniquet group was higher than that in the no-tourniquet group (21.5% compared with 8%; p = 0.019). CONCLUSION: The application of a tourniquet during TKA significantly increases the amount of calculated total blood loss and does not decrease the post-operative transfusion rate. Using a tourniquet in routine TKA exacerbates the early post-operative hypercoagulable status together with a higher incidence of below-knee asymptomatic DVT observed via conventional coagulation tests, TEG, and ultrasonic Doppler.


Assuntos
Artroplastia do Joelho , Artroplastia do Joelho/efeitos adversos , Perda Sanguínea Cirúrgica/prevenção & controle , Humanos , Estudos Prospectivos , Tromboelastografia , Torniquetes
8.
BMC Microbiol ; 19(1): 8, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30621594

RESUMO

BACKGROUND: As an important component of the causative agent of respiratory tract infections, enteric and eye infections, Human mastadenoviruses (HAdVs) species B spread easily in the crowd. In this study, we developed a recombinase polymerase amplification (RPA) assay for rapidly detecting HAdVs species B which was comprised of two different formats (real-time and lateral-flow device). RESULTS: This assay was confirmed to be able to detect 5 different HAdVs species B subtypes (HAdV-B3, HAdV-B7, HAdV-B11, HAdV-B14 and HAdV-B55) without cross-reactions with other subtypes and other respiratory tract pathogens. This RPA assay has not only highly sensitivity with low detection limit of 50 copies per reaction but also short reaction time (< 15 min per detection). Furthermore, the real-time RPA assay has excellent correlation with real-time PCR assay for detection of HAdVs species B presented in clinical samples. CONCLUSIONS: Thus, the RPA assay developed in this study provides an effective and portable approach for the rapid detection of HAdVs species B.


Assuntos
DNA Polimerase Dirigida por DNA/metabolismo , Mastadenovirus/classificação , Mastadenovirus/genética , Tipagem Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/normas , Recombinases/metabolismo , Virologia/métodos , Humanos , Limite de Detecção , Reação em Cadeia da Polimerase/normas , Reprodutibilidade dos Testes
9.
Int J Cancer ; 142(2): 357-368, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-28921531

RESUMO

Synchronous multifocal tumors are common in the hepatobiliary and pancreatic system but because of similarities in their histological features, oncologists have difficulty in identifying their precise tissue clonal origin through routine histopathological methods. To address this problem and assist in more precise diagnosis, we developed a computational approach for tissue origin diagnosis based on naive Bayes algorithm (TOD-Bayes) using ubiquitous RNA-Seq data. Massive tissue-specific RNA-Seq data sets were first obtained from The Cancer Genome Atlas (TCGA) and ∼1,000 feature genes were used to train and validate the TOD-Bayes algorithm. The accuracy of the model was >95% based on tenfold cross validation by the data from TCGA. A total of 18 clinical cancer samples (including six negative controls) with definitive tissue origin were subsequently used for external validation and 17 of the 18 samples were classified correctly in our study (94.4%). Furthermore, we included as cases studies seven tumor samples, taken from two individuals who suffered from synchronous multifocal tumors across tissues, where the efforts to make a definitive primary cancer diagnosis by traditional diagnostic methods had failed. Using our TOD-Bayes analysis, the two clinical test cases were successfully diagnosed as pancreatic cancer (PC) and cholangiocarcinoma (CC), respectively, in agreement with their clinical outcomes. Based on our findings, we believe that the TOD-Bayes algorithm is a powerful novel methodology to accurately identify the tissue origin of synchronous multifocal tumors of unknown primary cancers using RNA-Seq data and an important step toward more precision-based medicine in cancer diagnosis and treatment.


Assuntos
Algoritmos , Teorema de Bayes , Neoplasias do Sistema Biliar/diagnóstico , Biomarcadores Tumorais/genética , Linhagem da Célula/genética , Neoplasias Hepáticas/diagnóstico , Neoplasias Primárias Múltiplas/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Neoplasias do Sistema Biliar/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Neoplasias Hepáticas/genética , Neoplasias Primárias Múltiplas/genética , Neoplasias Pancreáticas/genética , Prognóstico
10.
Metab Eng ; 45: 32-42, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29174524

RESUMO

The rigidity of bacterial cell walls synthesized by a complicated pathway limit the cell shapes as coccus, bar or ellipse or even fibers. A less rigid bacterium could be beneficial for intracellular accumulation of poly-3-hydroxybutyrate (PHB) as granular inclusion bodies. To understand how cell rigidity affects PHB accumulation, E. coli cell wall synthesis pathway was reinforced and weakened, respectively. Cell rigidity was achieved by thickening the cell walls via insertion of a constitutive gltA (encoding citrate synthase) promoter in front of a series of cell wall synthesis genes on the chromosome of several E. coli derivatives, resulting in 1.32-1.60 folds increase of Young's modulus in mechanical strength for longer E. coli cells over-expressing fission ring FtsZ protein inhibiting gene sulA. Cell rigidity was weakened by down regulating expressions of ten genes in the cell wall synthesis pathway using CRISPRi, leading to elastic cells with more spaces for PHB accumulation. The regulation on cell wall synthesis changes the cell rigidity: E. coli with thickened cell walls accumulated only 25% PHB while cell wall weakened E. coli produced 93% PHB. Manipulation on cell wall synthesis mechanism adds another possibility to morphology engineering of microorganisms.


Assuntos
Parede Celular , Escherichia coli , Hidroxibutiratos/metabolismo , Poliésteres/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Parede Celular/genética , Parede Celular/metabolismo , Citrato (si)-Sintase/genética , Citrato (si)-Sintase/metabolismo , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Engenharia Metabólica
11.
RNA Biol ; 14(8): 1055-1063, 2017 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-27739910

RESUMO

Circular RNAs (circRNAs) have been identified in diverse eukaryotic species and are characterized by RNA backsplicing events. Current available methods for circRNA identification are able to determine the start and end locations of circRNAs in the genome but not their full-length sequences. In this study, we developed a method to assemble the full-length sequences of circRNAs using the backsplicing RNA-Seq reads and their corresponding paired-end reads. By applying the method to an rRNA-depleted/RNase R-treated RNA-Seq dataset, we for the first time identified full-length sequences of nearly 3,000 circRNAs in rice. We further showed that alternative circularization of circRNA is a common feature in rice and, surprisingly, found that the junction sites of a large number of rice circRNAs are flanked by diverse non-GT/AG splicing signals while most human exonic circRNAs are flanked by canonical GT/AG splicing signals. Our study provides a method for genome-wide identification of full-length circRNAs and expands our understanding of splicing signals of circRNAs.


Assuntos
Processamento Alternativo , Genoma de Planta , Oryza/genética , Sítios de Splice de RNA , RNA de Plantas/genética , RNA/genética , Sequência de Bases , Conjuntos de Dados como Assunto , Exorribonucleases/química , Humanos , Oryza/metabolismo , RNA/química , RNA/metabolismo , Estabilidade de RNA , RNA Circular , RNA de Plantas/química , RNA de Plantas/metabolismo , RNA Ribossômico/química , Análise de Sequência de RNA
12.
Plant J ; 83(4): 600-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26072920

RESUMO

Despite the importance of host-microbe interactions in natural ecosystems, agriculture and medicine, the impact of long-term (especially decades or longer) microbial colonization on the dynamics of host genomes is not well understood. The vegetable crop 'Jiaobai' with enlarged edible stems was domesticated from wild Zizania latifolia (Oryzeae) approximately 2000 years ago as a result of persistent infection by a fungal endophyte, Ustilago esculenta. Asexual propagation via infected rhizomes is the only means of Jiaobai production, and the Z. latifolia-endophyte complex has been maintained continuously for two centuries. Here, genomic analysis revealed that cultivated Z. latifolia has a significantly smaller repertoire of immune receptors compared with wild Z. latifolia. There are widespread gene losses/mutations and expression changes in the plant-pathogen interaction pathway in Jiaobai. These results show that continuous long-standing endophyte association can have a major effect on the evolution of the structural and transcriptomic components of the host genome.


Assuntos
Endófitos/patogenicidade , Genoma de Planta/genética , Poaceae/genética , Poaceae/microbiologia , Interações Hospedeiro-Patógeno/genética
13.
J Chem Theory Comput ; 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38898771

RESUMO

Rapid advancements in machine-learning methods have led to the emergence of machine-learning-based interatomic potentials as a new cutting-edge tool for simulating large systems with ab initio accuracy. Still, the community awaits universal interatomic models that can be applied to a wide range of materials without tuning neural network parameters. We develop a unified deep-learning interatomic potential (the DPA-Semi model) for 19 semiconductors ranging from group IIB to VIA, including Si, Ge, SiC, BAs, BN, AlN, AlP, AlAs, InP, InAs, InSb, GaN, GaP, GaAs, CdTe, InTe, CdSe, ZnS, and CdS. In addition, independent deep potential models for each semiconductor are prepared for detailed comparison. The training data are obtained by performing density functional theory calculations with numerical atomic orbitals basis sets to reduce the computational costs. We systematically compare various properties of the solid and liquid phases of semiconductors between different machine-learning models. We conclude that the DPA-Semi model achieves GGA exchange-correlation functional quality accuracy and can be regarded as a pretrained model toward a universal model to study group IIB to VIA semiconductors.

14.
Adv Mater ; : e2311830, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38501495

RESUMO

Colloidal Quantum Dots (CQDs) of mercury telluride (HgTe) hold particular appeal for infrared photodetection due to their widely tunable infrared absorption and good compatibility with silicon electronics. While advances in surface chemistry have led to improved CQD solids, the chemical stability of HgTe material is not fully emphasized. In this study, it is aimed to address this issue and identifies a Se-stabilization strategy based on the surface coating of Se on HgTe CQDs via engineering in the precursor reactivity. The presence of Se-coating enables HgTe CQDs with improved colloidal stability, passivation, and enhanced degree of freedom in doping tuning. This enables the construction of optimized p-i-n HgTe CQD infrared photodetectors with an ultra-low dark current 3.26 × 10-6 A cm⁻2 at -0.4 V and room-temperature specific detectivity of 5.17 × 1011 Jones at wavelength ≈2 um, approximately one order of magnitude improvement compared to that of the control device. The stabilizing effect of Se is well preserved in the thin film state, contributing to much improved device stability. The in-synthesis Se-stabilization strategy highlights the importance of the chemical stability of materials for the construction of semiconductor-grade CQD solids and may have important implications for other high-performance CQD optoelectronic devices.

15.
Adv Sci (Weinh) ; : e2400636, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38778554

RESUMO

Over the past years, the application potential of ferroelectric nanomaterials with unique physical properties for modern electronics is highlighted to a large extent. However, it is relatively challenging to fabricate inorganic ferroelectric nanomaterials, which is a process depending on a vacuum atmosphere at high temperatures. As significant complements to inorganic ferroelectric nanomaterials, the nanomaterials of molecular ferroelectrics are rarely reported. Here a low-cost room-temperature antisolvent method is used to synthesize free-standing 2D organic-inorganic hybrid perovskite (OIHP) ferroelectric nanosheets (NSs), that is, (CHA)2PbBr4 NSs (CHA = cyclohexylammonium), with an average lateral size of 357.59 nm and a thickness ranging from 10 to 70 nm. This method shows high repeatability and produces NSs with excellent crystallinity. Moreover, ferroelectric domains in single NSs can be clearly visualized and manipulated using piezoresponse force microscopy (PFM). The domain switching and PFM-switching spectroscopy indicate the robust in-plane ferroelectricity of the NSs. This work not only introduces a feasible, low-cost, and scalable method for preparing molecular ferroelectric NSs but also promotes the research on molecular ferroelectric nanomaterials.

16.
IEEE Trans Pattern Anal Mach Intell ; 45(8): 10535-10554, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37015127

RESUMO

Visible and infrared image fusion (VIF) has attracted a lot of interest in recent years due to its application in many tasks, such as object detection, object tracking, scene segmentation, and crowd counting. In addition to conventional VIF methods, an increasing number of deep learning-based VIF methods have been proposed in the last five years. Different types of methods, such as CNN-based, autoencoder-based, GAN-based, and transformer-based methods, have been proposed. Deep learning-based methods have undoubtedly become dominant methods for the VIF task. However, while much progress has been made, the field will benefit from a systematic review of these deep learning-based methods. In this paper we present a comprehensive review of deep learning-based VIF methods. We discuss motivation, taxonomy, recent development characteristics, datasets, and performance evaluation methods in detail. We also discuss future prospects of the VIF field. This paper can serve as a reference for VIF researchers and those interested in entering this fast-developing field.


Assuntos
Aprendizado Profundo , Algoritmos
17.
Water Res ; 239: 120029, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37182308

RESUMO

Microalgae-bacteria consortium (MBC) provides an alternative to sustainable treatment of human toilet wastewater (TWW) and resource recovery. This study compared the conventional activated sludge system and wastewater indigenous MBC system (IMBC) for nitrogen removal in TWW through the coupled partial nitrification (PN) and nitrite-type denitrification process. PN was firstly established by alternating FA and FNA. Subsequently, the successful PN maintenance with the nitrite accumulation rate ranging between 90.1-95.3% was achieved using two strategies: light irradiation with the appropriate specific light energy density at 0.0188-0.0598 kJ/mg VSS and the timely nitrite-type denitrification with the algae-secreted organics as the carbon source, eventually resulting in the nitrite accumulation rate ranging between 90.1-95.3%. In the IMBC-PN system, bacterial metabolism contributed to 91.5% of nitrogen removal and the rest was through microalgal assimilation. This study offers a sustainable hybrid IMBC-PN process for high NH4+-N strength wastewater treatment (e.g., TWW), which theoretically saves 23.5% aeration and 34.2% carbon source as well as reduces 17.0% sludge production.


Assuntos
Aparelho Sanitário , Microalgas , Humanos , Águas Residuárias , Nitrificação , Esgotos/microbiologia , Desnitrificação , Nitritos/metabolismo , Microalgas/metabolismo , Reatores Biológicos/microbiologia , Oxirredução , Bactérias/metabolismo , Nitrogênio/metabolismo , Carbono/metabolismo
18.
Materials (Basel) ; 16(4)2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36837118

RESUMO

The stress-strain constitutive model under uniaxial compression is a basic element and important characterization method for determining physical and mechanical properties in cement-based materials research. In this study, a stress-strain constitutive model under uniaxial compression was established, which was based on a new nano-stabilized soil (NSS) through typical mechanical tests and constitutive relationship research. The results indicate that the unconfined compressive strength (UCS) of the nano-stabilized soil was enhanced with the increase in curing period and nano-stabilizer dosage, and that the strength growth rate reaches the maximum at a 12% dosage in the tested samples. The UCS of NSS under a 12% dosage is about 10~15% higher than that of ordinary stabilized soil (SS) without nano doping, and 25~40% higher compared with grade 42.5 cement-soil. The established constitutive model could accurately describe the linear-elastic and elastic-plastic deformation characteristics of NSS under uniaxial compression, which will be conducive to revealing the curve variation law of the stress-strain process. The research results could provide scientific support for the theoretical innovation and engineering application of green environmental protection materials.

19.
Sci Total Environ ; 877: 162702, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36898547

RESUMO

The control of pH is effective for inhibiting methanogenesis in the chain elongation fermentation (CEF) system. However, obscure conclusions exist especially with regard to the underlying mechanism. This study comprehensively explored the responses of methanogenesis in granular sludge at various pH levels, ranging from 4.0 to 10.0, from multiple aspects including methane production, methanogenesis pathway, microbial community structure, energy metabolism and electron transport. Results demonstrated that compared with that at pH 7.0, pH at 4.0, 5.5, 8.5 and 10.0 triggered a 100%, 71.7%, 23.8% and 92.1% suppression on methanogenesis by the end of 3 cycles lasting 21 days. This might be explained by the remarkably inhibited metabolic pathways and intracellular regulations. To be more specific, extreme pH conditions decreased the abundance of the acetoclastic methanogens. However, obligate hydrogenotrophic and facultative acetolactic/hydrogenotrophic methanogens were significantly enriched by 16.9%-19.5 fold. pH stress reduced the gene abundance and/or activity of most enzymes involved in methanogenesis such as acetate kinase (by 81.1%-93.1%), formylmethanofuran dehydrogenase (by 10.9%-54.0%) and tetrahydromethanopterin S-methyltransferase (by 9.3%-41.5%). Additionally, pH stress suppressed electron transport via improper electron carriers and decreased electron amount as evidenced by 46.3%-70.4% reduced coenzyme F420 content and diminished abundance of CO dehydrogenase (by 15.5%-70.5%) and NADH:ubiquinone reductase (by 20.2%-94.5%). pH stress also regulated energy metabolism with inhibited ATP synthesis (e.g., ATP citrate synthase level reduced by 20.1%-95.3%). Interestingly, the protein and carbohydrate content secreted in EPS failed to show consistent responses to acidic and alkaline conditions. Specifically, when compared with pH 7.0, the acidic condition remarkably reduced the levels of total EPS and EPS protein while both levels were enhanced in the alkaline condition. However, the EPS carbohydrate content at pH 4.0 and 10.0 both decreased. This study is expected to promote the understanding of the pH control-induced methanogenesis inhibition in the CEF system.


Assuntos
Euryarchaeota , Euryarchaeota/genética , Euryarchaeota/metabolismo , Transporte de Elétrons , Fermentação , Redes e Vias Metabólicas , Concentração de Íons de Hidrogênio , Metano/metabolismo , Anaerobiose , Reatores Biológicos
20.
Pest Manag Sci ; 79(10): 3767-3772, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37202373

RESUMO

BACKGROUND: Locusts and grasshoppers are pests of many agricultural crops, and their frequent outbreaks worldwide threaten food security. Microbial control agents are currently used to suppress the early (nymphal) stages of pests, but they are often less effective against adults, which are primarily responsible for locust plagues. The fungal pathogen Aspergillus oryzae XJ-1 has high pathogenicity in locust nymphs. To assess its potential for controlling locust adults, we evaluated the virulence of A. oryzae XJ-1 (i.e., locust Aspergillus, LAsp) in locust adults using laboratory, field-cage experiments, and a field trial. RESULTS: The lethal concentration of LAsp in adult Locusta migratoria was 3.58 ± 0.09 × 105 conidia mL-1 15 days after inoculation in the laboratory. A field-cage experiment showed that the mortalities of adult L. migratoria were 92.0 ± 4.6% and 90.1 ± 3.2% 15 days after inoculation with 3 × 105 and 3 × 103 conidia m-2 of LAsp, respectively. A large-scale field trial of 666.6 ha was conducted, in which a LAsp water suspension was applied at a concentration of 2 × 108 conidia mL-1 in 15 L ha-1 by aerial spraying via drones. The densities of mixed populations of L. migratoria and Epacromius spp. were significantly reduced by 85.4 ± 7.9%-94.9 ± 5.1%. In addition, the infection rates of surviving locusts collected from the treated plots were 79.6% and 78.3% on the 17th and 31st day after treatment, respectively. CONCLUSION: These results indicate that A. oryzae XJ-1 is highly virulent in adult locusts and that it has high potential for the control of locusts. © 2023 Society of Chemical Industry.


Assuntos
Aspergillus oryzae , Locusta migratoria , Ortópteros , Animais , Virulência , Locusta migratoria/microbiologia
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