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1.
Cell ; 187(16): 4261-4271.e17, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-38964329

RESUMO

The entry of coronaviruses is initiated by spike recognition of host cellular receptors, involving proteinaceous and/or glycan receptors. Recently, TMPRSS2 was identified as the proteinaceous receptor for HCoV-HKU1 alongside sialoglycan as a glycan receptor. However, the underlying mechanisms for viral entry remain unknown. Here, we investigated the HCoV-HKU1C spike in the inactive, glycan-activated, and functionally anchored states, revealing that sialoglycan binding induces a conformational change of the NTD and promotes the neighboring RBD of the spike to open for TMPRSS2 recognition, exhibiting a synergistic mechanism for the entry of HCoV-HKU1. The RBD of HCoV-HKU1 features an insertion subdomain that recognizes TMPRSS2 through three previously undiscovered interfaces. Furthermore, structural investigation of HCoV-HKU1A in combination with mutagenesis and binding assays confirms a conserved receptor recognition pattern adopted by HCoV-HKU1. These studies advance our understanding of the complex viral-host interactions during entry, laying the groundwork for developing new therapeutics against coronavirus-associated diseases.


Assuntos
Serina Endopeptidases , Glicoproteína da Espícula de Coronavírus , Internalização do Vírus , Humanos , Serina Endopeptidases/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Polissacarídeos/metabolismo , Polissacarídeos/química , Células HEK293 , Ligação Proteica , Receptores Virais/metabolismo , Receptores Virais/química , Coronavirus/metabolismo , Modelos Moleculares
2.
J Virol ; 98(3): e0112923, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38305155

RESUMO

The global circulation of clade 2.3.4.4b H5Ny highly pathogenic avian influenza viruses (HPAIVs) in poultry and wild birds, increasing mammal infections, continues to pose a public health threat and may even form a pandemic. An efficacious vaccine against H5Ny HPAIVs is crucial for emergency use and pandemic preparedness. In this study, we developed a parainfluenza virus 5 (PIV5)-based vaccine candidate expressing hemagglutinin (HA) protein of clade 2.3.4.4b H5 HPAIV, termed rPIV5-H5, and evaluated its safety and efficacy in mice and ferrets. Our results demonstrated that intranasal immunization with a single dose of rPIV5-H5 could stimulate H5-specific antibody responses, moreover, a prime-boost regimen using rPIV5-H5 stimulated robust humoral, cellular, and mucosal immune responses in mice. Challenge study showed that rPIV5-H5 prime-boost regimen provided sterile immunity against lethal clade 2.3.4.4b H5N1 virus infection in mice and ferrets. Notably, rPIV5-H5 prime-boost regimen provided protection in mice against challenge with lethal doses of heterologous clades 2.2, 2.3.2, and 2.3.4 H5N1, and clade 2.3.4.4h H5N6 viruses. These results revealed that rPIV5-H5 can elicit protective immunity against a diverse clade of highly pathogenic H5Ny virus infection in mammals, highlighting the potential of rPIV5-H5 as a pan-H5 influenza vaccine candidate for emergency use.IMPORTANCEClade 2.3.4.4b H5Ny highly pathogenic avian influenza viruses (HPAIVs) have been widely circulating in wild birds and domestic poultry all over the world, leading to infections in mammals, including humans. Here, we developed a recombinant PIV5-vectored vaccine candidate expressing the HA protein of clade 2.3.4.4b H5 virus. Intranasal immunization with rPIV5-H5 in mice induced airway mucosal IgA responses, high levels of antibodies, and robust T-cell responses. Importantly, rPIV5-H5 conferred complete protection in mice and ferrets against clade 2.3.4.4b H5N1 virus challenge, the protective immunity was extended against heterologous H5Ny viruses. Taken together, our data demonstrate that rPIV5-H5 is a promising vaccine candidate against diverse H5Ny influenza viruses in mammals.


Assuntos
Virus da Influenza A Subtipo H5N1 , Virus da Influenza A Subtipo H5N6 , Vacinas contra Influenza , Infecções por Orthomyxoviridae , Vírus da Parainfluenza 5 , Animais , Humanos , Camundongos , Furões/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Imunidade Celular , Imunidade Humoral , Imunidade nas Mucosas , Virus da Influenza A Subtipo H5N1/química , Virus da Influenza A Subtipo H5N1/classificação , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/imunologia , Virus da Influenza A Subtipo H5N6/química , Virus da Influenza A Subtipo H5N6/classificação , Virus da Influenza A Subtipo H5N6/genética , Virus da Influenza A Subtipo H5N6/imunologia , Influenza Aviária/imunologia , Influenza Aviária/prevenção & controle , Influenza Aviária/transmissão , Influenza Aviária/virologia , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/efeitos adversos , Vacinas contra Influenza/genética , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/virologia , Preparação para Pandemia/métodos , Vírus da Parainfluenza 5/genética , Vírus da Parainfluenza 5/imunologia , Vírus da Parainfluenza 5/metabolismo , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Administração Intranasal , Aves Domésticas/virologia , Imunoglobulina A/imunologia , Linfócitos T/imunologia
3.
Genomics ; 116(2): 110818, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38431032

RESUMO

Sheep breeds with hair-shedding traits have many advantages over non-shedding sheep breeds, not only because of reduced shearing labor and feeding management costs but also because it reduces in vitro parasites and improves adaptability to summer heat stress. The wool of Dorper sheep naturally sheds in spring due to the periodic growth of hair follicles. CircRNAs primarily regulate the morphogenesis of hair follicles through the ceRNA mechanism. In this study, five 2-year-old Dorper ewes with extreme hair-shedding phenotype (S) and three Dorper ewes with non-shedding (N) phenotype were selected for subsequent analyses. For RNA extraction, skin tissues were collected on 27th September 2019 (S1, N1), 3rd January 2020 (S2, N2), and 17th March 2020 (S3, N3), which were then subjected to RNA-seq. RNA-seq technology revealed 20,185 novel circRNAs in the hair follicles of Dorper sheep. Among them, 1450 circRNAs were differentially expressed (DE). Clustering heatmap and expression pattern analyses were performed on DE circRNAs, which indicated 78 circRNAs with T pattern (Telogen, highly expressed in telogen), and the source genes for candidate circRNAs were further screened by functional enrichment analysis, which identified 13 crucial genes enriched in pathways associated with hair follicle development. Additionally, a ceRNA regulatory network comprising 4 circRNAs, 11 miRNAs, and 13 target genes was constructed. Overall, this study screened circRNAs that may be associated with the telogen phase of hair follicles in sheep, providing a relevant theoretical basis for wool shedding in sheep and for breeding Dorper sheep with automatic wool shedding.


Assuntos
MicroRNAs , RNA Circular , Ovinos/genética , Animais , Feminino , RNA Circular/metabolismo , RNA Endógeno Competitivo , Folículo Piloso/metabolismo , Carneiro Doméstico/genética , MicroRNAs/metabolismo
4.
Nano Lett ; 24(26): 8134-8142, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38900138

RESUMO

Developing highly efficient and carbon monoxide (CO)-tolerant platinum (Pt) catalysts for the formic acid oxidation reaction (FAOR) is vital for direct formic acid fuel cells (DFAFCs), yet it is challenging due to the high energy barrier of direct intermediates (HCOO* and COOH*) as well as the CO poisoning issues associated with Pt alloy catalysts. Here we present a versatile biphasic strategy by creating a hexagonal/cubic crystalline-phase-synergistic PtPb/C (h/c-PtPb/C) catalyst to tackle the aforementioned issues. Detailed investigations reveal that h/c-PtPb/C can simultaneously facilitate the adsorption of direct intermediates while inhibiting CO adsorption, thereby significantly improving the activation and CO spillover. As a result, h/c-PtPb/C showcases an outstanding FAOR activity of 8.1 A mgPt-1, which is 64.5 times higher than that of commercial Pt/C and significantly surpasses monophasic PtPb. Moreover, the h/c-PtPb/C-based membrane electrode assembly exhibits an exceptional peak power density of 258.7 mW cm-2 for practical DFAFC applications.

5.
J Am Chem Soc ; 146(1): 617-626, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38110416

RESUMO

The adsorptive separation of propylene and propane offers an energy-efficient alternative to the conventional cryogenic distillation technology. However, developing porous adsorbents with both high equilibrium and kinetic selectivity remains extremely challenging due to the similar size and physical properties of these gases. Herein, this work reports a ligand racemization strategy to construct quasi-discrete pores in MOFs for a synergistically enhanced thermodynamic and kinetic separation performance. The use of enantiopure l-malic acid versus racemic dl-malic acid as ligands afforded isoreticular Ni-based MOFs with contrasting one-dimensional channels (l-mal-MOF) and quasi-discrete cavities connected by small windows (dl-mal-MOF). The periodic pore constrictions in dl-mal-MOF significantly increased the differentiation in diffusion rates and binding energies between propylene and propane. dl-mal-MOF exhibited an exceptional propylene uptake of 1.82 mmol/g at 0.05 bar and 298 K along with an ultrahigh equilibrium-kinetic combined selectivity of 62.6. DFT calculations and MD simulations provided insights into the synergistic mechanism of preferential propylene adsorption and diffusion. Breakthrough column experiments demonstrated the excellent separation and high-purity recovery of propylene over propane on dl-mal-MOF. The robust stability and facile regeneration highlight its potential for propylene purification applications.

6.
J Hepatol ; 80(2): 194-208, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38438948

RESUMO

BACKGROUND & AIMS: Hepatocyte apoptosis, a well-defined form of cell death in non-alcoholic steatohepatitis (NASH), is considered the primary cause of liver inflammation and fibrosis. However, the mechanisms underlying the regulation of hepatocyte apoptosis in NASH remain largely unclear. We explored the anti-apoptotic effect of hepatocyte CD1d in NASH. METHODS: Hepatocyte CD1d expression was analyzed in patients with NASH and mouse models. Hepatocyte-specific gene overexpression or knockdown and anti-CD1d crosslinking were used to investigate the anti-apoptotic effect of hepatocyte CD1d on lipotoxicity-, Fas-, and concanavalin (ConA)-mediated liver injuries. A high-fat diet, a methionine-choline-deficient diet, a Fas agonist, and ConA were used to induce lipotoxic and/or apoptotic liver injuries. Palmitic acid was used to mimic lipotoxicity-induced apoptosis in vitro. RESULTS: We identified a dramatic decrease in CD1d expression in hepatocytes of patients with NASH and mouse models. Hepatocyte-specific CD1d overexpression and knockdown experiments collectively demonstrated that hepatocyte CD1d protected against hepatocyte apoptosis and alleviated hepatic inflammation and injuries in NASH mice. Furthermore, decreased JAK2-STAT3 signaling was observed in NASH patient livers. Mechanistically, anti-CD1d crosslinking on hepatocytes induced tyrosine phosphorylation of the CD1d cytoplasmic tail, leading to the recruitment and phosphorylation of JAK2. Phosphorylated JAK2 activated STAT3 and subsequently reduced apoptosis in hepatocytes, which was associated with an increase in anti-apoptotic effectors (Bcl-xL and Mcl-1) and a decrease in pro-apoptotic effectors (cleaved-caspase 3/7). Moreover, anti-CD1d crosslinking effectively protected against Fas- or ConA-mediated hepatocyte apoptosis and liver injury in mice. CONCLUSIONS: Our study uncovered a previously unrecognized anti-apoptotic CD1d-JAK2-STAT3 axis in hepatocytes that conferred hepatoprotection and highlighted the potential of hepatocyte CD1d-directed therapy for liver injury and fibrosis in NASH, as well as in other liver diseases associated with hepatocyte apoptosis. IMPACT AND IMPLICATIONS: Excessive and/or sustained hepatocyte apoptosis is critical in driving liver inflammation and injury. The mechanisms underlying the regulation of hepatocyte apoptosis in non-alcoholic steatohepatitis (NASH) remain largely unclear. Here, we found that CD1d expression in hepatocytes substantially decreases and negatively correlates with the severity of liver injury in patients with NASH. We further revealed a previously unrecognized anti-apoptotic CD1d-JAK2-STAT3 signaling axis in hepatocytes, which confers significant protection against liver injury in NASH and acute liver diseases. Thus, hepatocyte CD1d-targeted therapy could be a promising strategy to manipulate liver injury in both NASH and other hepatocyte apoptosis-related liver diseases.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Animais , Humanos , Camundongos , Apoptose , Concanavalina A , Modelos Animais de Doenças , Hepatócitos , Inflamação
7.
Chembiochem ; 25(5): e202300849, 2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-38116888

RESUMO

Engineering efficient biocatalysts is essential for metabolic engineering to produce valuable bioproducts from renewable resources. However, due to the complexity of cellular metabolic networks, it is challenging to translate success in vitro into high performance in cells. To meet such a challenge, an accurate and efficient quantification method is necessary to screen a large set of mutants from complex cell culture and a careful correlation between the catalysis parameters in vitro and performance in cells is required. In this study, we employed a mass-spectrometry based high-throughput quantitative method to screen new mutants of 2-pyrone synthase (2PS) for triacetic acid lactone (TAL) biosynthesis through directed evolution in E. coli. From the process, we discovered two mutants with the highest improvement (46 fold) in titer and the fastest kcat (44 fold) over the wild type 2PS, respectively, among those reported in the literature. A careful examination of the correlation between intracellular substrate concentration, Michaelis-Menten parameters and TAL titer for these two mutants reveals that a fast reaction rate under limiting intracellular substrate concentrations is important for in-cell biocatalysis. Such properties can be tuned by protein engineering and synthetic biology to adopt these engineered proteins for the maximum activities in different intracellular environments.


Assuntos
Compostos de Boro , Cloranfenicol/análogos & derivados , Escherichia coli , Pironas , Escherichia coli/genética , Catálise , Biocatálise , Espectrometria de Massas
8.
Bioresour Technol ; 399: 130595, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38493936

RESUMO

Poplar is widely used in the paper industry and accompanied by abundant branches waste, which is potential feedstock for bioethanol production. Acid-chlorite pretreatment can selectively remove lignin, thereby significantly increasing enzymatic efficiency. Moreover, lignin residues valorization via gasification-syngas fermentation can achieve higher fuel yield. Herein, environmental and economic aspects were conducted to assess technological routes, which guides further process optimization. Life cycle assessment results show that wood-based biorefineries especially coupling scenarios have significant advantages in reducing global warming potential in contrast to fossil-based automotive fuels. Normalization results indicate that acidification potential surpasses other indicators as the primary impact category. In terms of economic feasibility, coupling scenarios present better investment prospects. Bioethanol yield is the most critical factor affecting market competitiveness. Minimum ethanol selling price below ethanol international market price is promising with higher-levels technology. Further work should be focused on technological breakthrough, consumable reduction or replacement.


Assuntos
Etanol , Lignina , Animais , Lignina/química , Etanol/química , Madeira/metabolismo , Biotecnologia/métodos , Fermentação , Estágios do Ciclo de Vida
9.
Animals (Basel) ; 14(11)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38891646

RESUMO

This study evaluated the nutrition composition, the nutrient digestibility, and the energy value of six protein ingredients used in pet food by the difference method in six beagles within a 7 × 6 incomplete Latin square design. The results showed that the apparent total tract digestibility of gross energy (GE) and organic matter (OM) in beagles fed the fish meal (FM) and corn gluten meal (CGM) diets was higher than for those fed the meat and bone meal (MBM), soybean meal (SBM), mealworm meal (MM), and yeast extract (YE) diets (p < 0.05). The digestible energy (DE), metabolizable energy (ME), and net energy (NE) of the MM diet were greater than the other diets, and MBM was the lowest (p < 0.05). The ME of protein ingredients was positively correlated with organic matter and negatively correlated with the ash content. The NE of protein ingredients was positively correlated with the crude protein content and negatively correlated with the ash content. The study resulted in predictive energy equations for protein ingredients that were more accurate than the NRC's predictive equation of ME when the ash content of the ingredient was more than 30% DM. In conclusion, the nutrient digestibility and energy value of corn gluten meal were similar to those of fish meal and those of soybean meal were similar to yeast extract. All predictive energy equations for six protein feedstuffs had slight differences with measured energy values.

10.
Heliyon ; 10(14): e34905, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39149071

RESUMO

Digital transformation has emerged as a key driver of high-quality enterprise development and an essential tool in forging an innovation-driven paradigm.Existing studies fail to delve into the specific mechanisms of their impact on firms' innovation performance, and views on their impact are divergent. Some studies suggest that digital transformation can enhance innovation performance, while others point out that it may have negative impacts, and cannot clearly answer how big data capabilities and organisational agility play a role in the digital transformation process. Therefore, based on dynamic capability theory and systems engineering theory, this study adopts the logical framework of "strategy-behaviour-performance" to systematically explore the process of digital transformation that enhances firms' innovation performance through the enhancement of big data capability and organisational agility. By empirically analysing the survey data of 476 manufacturing enterprises in China, the study reveals the chain-mediated effects of big data capability and organisational agility, and confirms the key roles of both in the transformation process. The findings suggest that digital transformation significantly improves firms' innovation performance, and that the dual mediating effects of big data capability and organisational agility are important links in its influencing mechanism. These findings not only provide empirical support for the theoretical model of digital transformation, but also provide practical guidance for enterprises to formulate strategies and optimise resource allocation in the digital era. We suggest that enterprises should strengthen the cultivation of big data capabilities and organisational agility while promoting digital transformation to better adapt to and lead market changes.

11.
Health Phys ; 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39052007

RESUMO

ABSTRACT: This study investigated indoor radon concentrations in modern residential buildings in the Cold Area and Severe Cold Area in China. A total of 19 cities covering 16 provinces were selected with 1,610 dwellings measured for indoor radon concentration. The arithmetic mean and geometric mean of indoor radon concentration were 68 Bq m-3 and 57 Bq m-3, respectively. It was found that indoor radon concentrations were much higher in the Severe Cold Area than those in the Cold Area. The indoor radon concentrations showed an increasing trend for newly constructed buildings. It was estimated that the average effective dose from inhalation of indoor radon is 2.15 mSv and 1.60 mSv for the Severe Cold Area and Cold Area, respectively. The more and more rigid energy-saving design for residential buildings in the Severe Cold Area and Cold Area has an obvious impact on the increased trend of indoor radon due to extremely low air exchange rate in China.

12.
Artigo em Inglês | MEDLINE | ID: mdl-39145480

RESUMO

The unique features of two-dimensional (2D) materials provide significant opportunities for the development of transparent and flexible electronics. Recently, ambipolar 2D semiconductors have advanced innovative applications such as CMOS-like circuits, reconfigurable circuits, and ultrafast neuromorphic image sensors. Here, we report on the fabrication of full 2D ambipolar field-effect transistors (FETs), in which graphene serves as the source/drain/gate electrodes, WSe2 is for the channel, and h-BN is for the dielectric. The produced ambipolar FETs exhibit comparable on-currents in the n-branch and p-branch with on/off ratios up to 108. By using two ambipolar FETs in series, a CMOS-like inverter is demonstrated with a maximum gain of up to 147, which can work in both the first and third quadrants by controlling the supply voltages and input voltages. The full 2D ambipolar FETs yield a transmittance of over 70% for visible light on transparent glass and achieve a curvature radius of less than 0.5 cm for bending on polyethylene terephthalate (PET) substrate. The work is helpful for the application of ambipolar 2D materials-based devices in transparent and flexible electronics.

13.
Chem Sci ; 15(24): 9281-9286, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38903217

RESUMO

Self-assembly via coordination bonding facilitates the creation of diverse inorganic-organic molecular hybrids with distinct structures and properties. Recent advances in this field have been driven by the versatility of organic ligands and inorganic units. Lacunary polyoxometalates are a class of well-defined metal-oxide clusters with a customizable number of reactive sites and bond directions, which make them promising inorganic units for self-assembled molecular hybrids. Herein, we report a novel synthesis method for self-assembled molecular hybrids utilizing the reversible coordination of multidentate imidazole ligands to the vacant sites of lacunary polyoxometalates. We synthesized self-assembled molecular hybrids including monomer, dimers, and tetramer, demonstrating the potential of our method for constructing intricate hybrids with tailored properties and functionalities.

14.
IEEE J Biomed Health Inform ; 28(8): 4577-4587, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38776201

RESUMO

This study designs a wearable sensing system for locomotion mode recognition using lower-limb skin surface curvature deformation caused by the morphological changes of musculotendinous complexes and soft tissues. Flexible bending sensors are embedded into stretch pants, enabling curvature deformations of specific skin segments above lower-limb muscle groups to be captured in a noncontact manner. To evaluate the performance of this system, we conducted experiments on eight able-bodied subjects completing seven common locomotive activities, including walking, running, ramp ascending/descending, stair ascending/descending, and standing. The system measured seven channels of deformation signals from two cross-sections on the shank and the thigh. The collected signals were distinguishable across different locomotion modes and exhibited consistency when monitoring steps. Using selected time-domain features and a linear discriminant analysis (LDA) classifier enabled the proposed system to continuously recognize locomotion modes with an average accuracy of 96.5%. Furthermore, the system maintains recognition performance with 95.7% accuracy even after removing and reapplying the sensors. Finally, we conducted comparison experiments to analyze how window length, feature selection, and the number of channels affect recognition performance, providing insights for optimization. We believe that this novel signal platform holds great potential as a valuable supplementary tool in wearable human motion detection, enriching the information diversity for motion analysis, and enabling new possibilities for further advancements and applications in fields including biomedical engineering, textiles, and computer graphics.


Assuntos
Locomoção , Processamento de Sinais Assistido por Computador , Dispositivos Eletrônicos Vestíveis , Humanos , Masculino , Adulto , Locomoção/fisiologia , Adulto Jovem , Miografia/métodos , Miografia/instrumentação , Feminino , Eletromiografia/métodos , Desenho de Equipamento
15.
RSC Adv ; 14(11): 7350-7358, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38433938

RESUMO

High-performance thermal insulation materials with broad application prospects have attracted great attention. The introduction of new microstructures into thermal protection materials can significantly improve the thermal insulation performance. The tubular microstructure has obvious advantages such as thermal insulation, lightweight, mechanical, and other properties. Therefore, the microtubular structure has become an important reference microstructure for the development of high-performance thermal insulation materials. In this paper, the carbon/ZrO2 aerogel composite microtube superfoams with excellent thermal protection properties were prepared by a vacuum filtration and high-temperature carbonization method. The ZrO2 aerogel precursor solution can be quickly and uniformly adsorbed on the inner and outer walls of cellulose microtubules. These adsorbed ZrO2 aerogel precursor solution films can be converted into ZrO2 alcohol gel shells under the acceleration and promotion effect of citric acid at 65 °C. The micromorphology of the ZrO2 aerogel shell on the inner and outer walls of the composite microtubes can be efficiently controlled by the concentration of the ZrO2 aerogel precursor solution and the carbonization temperature. The carbon/ZrO2 aerogel composite microtube superfoam exhibits a lower thermal conductivity, lower density, good mechanical properties, and high ablation resistance. The thermal conductivity of the carbon/ZrO2 aerogel composite microtube superfoam is as low as 0.040 ± 0.001 W m-1 K-1. The residual rate of the carbon/ZrO2 aerogel composite microtube superfoam is still as high as 84.33% after butane flame ablation for up to 3600 seconds.

16.
Nanomaterials (Basel) ; 14(5)2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38470779

RESUMO

The leakage of the electronic current of a laser diode (LD) has some significant influences on the performance of the LD. In this study, commercial simulation software LASTIP is used to numerically evaluate the performances of LDs by using different wavelengths and Al contents of the electron blocking layer (EBL). These LDs a adopt multilayer structure, which contains cladding layers, waveguide layers, multiple quantum well layers, contact layers and an AlxGa1-xN EBL. The influence mechanism of EBL is theoretically examined by analyzing the simulated performances. It is found that for short-wavelength violet LDs, the electrical and optical properties of the LD will reach the optimum state when the Al content (x) in the EBL is nearly 0.25. For long-wavelength green LDs, it will achieve optimum electrical and optical properties when the Al content in the EBL is as low as possible. We also compare the simulation results of LDs with emission wavelengths in the range of violet and green, including blue cyan, for a more general evaluation. According to the simulated results, it is verified that the influence of the EBL's Al content on LD performance enhances as the wavelength increases.

17.
Environ Sci Pollut Res Int ; 31(17): 26076-26088, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38491240

RESUMO

With the interaction between global climate change and unreasonable human utilization, the alpine meadows on the Qinghai-Tibet Plateau have suffered various weathering degrees. Uncovering the degradation mechanism and restoration strategies can be facilitated by gaining insights into the diversity of soil microflora during meadow degradation. Therefore, we used Illumina sequencing technology to investigate the patterns of soil microbial diversity, microbial community composition, and the driving factors of microbial change in all non-degraded (ND), lightly degraded (LD), moderately degraded (MD), and severely degraded (SD) alpine meadows in the southeastern Qinghai-Tibet Plateau. Our results pointed out that with the intensification of degradation, vegetation characteristics were significantly reduced, and soil parameters significantly varied among all degraded meadows. The contents of soil organic carbon (SOC), total nitrogen (TN), available phosphorus (AN), and total phosphorous (AK) in soils decreased with the increase of degradation. The dominant bacterial phyla were the same regardless of the meadow degradation level with Actinobacteria (37.67%) and Proteobacteria (20.62%) having the highest relative abundance. Meanwhile, the dominant fungi were Ascomycota (49.9%). Based on the linear discriminant analysis (LDA) and effect size (LEfSe) method, 38 bacterial and 49 fungal species were found to be affected in the degraded alpine meadow, most of which belonged to Actinobacteria and Ascomycota, respectively. Mantel test analysis illustrated that the bacterial community was mainly significantly dependent on below-ground biomass, pH, soil organic carbon, and total nitrogen, while the fungal community was significantly dependent on soil organic carbon, total nitrogen, available nitrogen, and available potassium. These results suggest that the degeneration of alpine meadows contributes to the variability of the diversity and composition of microflora on the Tibetan plateau. Yet this effect is mainly dependent on soil factors.


Assuntos
Pradaria , Microbiologia do Solo , Humanos , Tibet , Solo/química , Carbono , Nitrogênio/química , Bactérias
18.
J Hazard Mater ; 477: 135288, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39047564

RESUMO

In this work, a novel CuMn-Sb-SnO2 anode is developed by a simple, low-cost preparation process. The doping of Cu and Mn causes surface reconstruction, which optimizes its electronic structure, compared to the Sb-SnO2 anode. Experimental results demonstrate that the levofloxacin degradation kinetics constant in the CuMn-Sb-SnO2 system (0.188 min-1) was 8.5 times higher than that in the Sb-SnO2 system, which is surpassing most reported anodes. Moreover, electrochemical characterization also revealed that the CuMn-Sb-SnO2 anode possessed more active sites, higher OEP potential, and lower charge transfer resistance. Notably, electrochemical characterization and EPR experiments confirmed the formation of Cu (III), highlighting their crucial role in promoting the generation of •OH during the catalytic process. Additionally, theoretical calculations and XPS analysis revealed that Cu and Mn rely on self-mediated redox shuttles to act as "electron porters", significantly accelerating internal electron transfer between Sn and Sb to enhance the production of •OH. Furthermore, the CuMn-Sb-SnO2 anode exhibits great practicability due to its efficient degradation of various antibiotics. This study offers valuable new insights into developing novel electrodes for the efficient degradation of antibiotic wastewater.

19.
Bioresour Technol ; 408: 131154, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39053598

RESUMO

Considering the challenges for both single and traditional two-stage treatments, advanced oxidation and biodegradation, in the treatment of actual coking wastewater, an intimately coupled catalytic ozonation and biodegradation (ICOB) reactor was developed. In this study, ICOB treatment significantly enhanced the removal of Cu2+, Fe3+, and color by 39 %, 45 %, and 52 %, respectively, outperforming biodegradation. Catalytic ozonation effectively breaking down unsaturated organic substances and high-molecular-weight dissolved organic matter into smaller, more biodegradable molecules. Compared with biodegradation, the ICOB system significantly increased the abundances of Pseudomonas, Sphingopyxis, and Brevundimonas by âˆ¼ 96 %, ∼67 %, and âˆ¼ 85 %, respectively. These microorganisms, possessing genes for degrading phenol, aromatic compounds, polycyclic aromatics, and sulfur metabolism, further enhanced the mineralization of intermediates. Consequently, the ICOB system outperformed biodegradation and catalytic ozonation treatments, exhibiting chemical oxygen demand removal rate of âˆ¼ 58 % and toxicity reduction of âˆ¼ 47 %. Overall, the ICOB treatment showcases promise for practical engineering applications in coking wastewater treatment.


Assuntos
Biodegradação Ambiental , Reatores Biológicos , Coque , Metais Pesados , Ozônio , Águas Residuárias , Poluentes Químicos da Água , Águas Residuárias/química , Ozônio/química , Catálise , Poluentes Químicos da Água/metabolismo , Oxirredução , Óxidos/química , Compostos de Cálcio/química , Cor , Análise da Demanda Biológica de Oxigênio , Purificação da Água/métodos , Estudos de Viabilidade , Pseudomonas/metabolismo , Compostos Orgânicos
20.
RSC Adv ; 14(18): 12911-12922, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38650688

RESUMO

Thermal insulation materials with good flame-retardant properties have attracted widespread attention because of their huge application potential. Traditional petrochemical-based polymer insulation materials are flammable and have problems with environmental pollution. The microtubule structure is a perfect microstructure with excellent thermal insulation performance. In addition, the microtubule structure also has low density and high elasticity. Therefore, the microtubule structure is an important reference microstructure for the development of efficient thermal insulation materials. In this paper, a cellulose/SiO2 composite microtube thermal insulation superfoam has been successfully prepared. Cellulose microtubules were successfully prepared from poplar sawdust by chemical methods. The SiO2 aerogel precursor solution can be quickly adsorbed by the delignified cellulose microtubes. The SiO2 aerogel shells are evenly distributed only on the inner and outer walls of the delignified cellulose microtubes. The cellulose/SiO2 microtube composite (CSMC) superfoam exhibits low density, good mechanical properties, and low thermal conductivity (as low as 0.042 ± 0.0018 W m-1 K-1). The CSMC superfoam exhibits excellent self-extinguishing and flame-retardant properties. After being burned by a butane flame, the superfoam still has certain mechanical properties. The thermal conductivity of the B-CSMC superfoam (the CSMC superfoam burned by a butane flame) is about 0.050 W m-1 K-1. The B-CSMC superfoam remained almost unchanged after being continuously ablated by a butane flame for 3600 seconds.

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