Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 282
Filtrar
1.
Chem Commun (Camb) ; 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39015949

RESUMO

Herein, a biomimetic hierarchical porous high entropy alloy (BHP-HEA) is prepared by a strategy combining selective laser melting and selective phase dissolution. It exhibited excellent seawater splitting performance, which only needs a low potential of 1.53 V to realize a current density of 100 mA cm-2, with exceptional stability.

2.
Huan Jing Ke Xue ; 45(7): 4228-4240, 2024 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-39022969

RESUMO

In order to elucidate the changes in the soil fungal community and soil organic carbon components of a Jasminum sambac garden after straw and biochar application, we measured the organic carbon components and soil fungal community of the 0-15 cm soil layer in a J. sambac garden, which was divided into a control group, straw treatment group, and biochar treatment group. The carbon pool management index (CPMI) was also calculated. The results showed that the diversity of the soil fungal community was decreased after straw and biochar application, and the structure of dominant fungal genera was changed in each treatment. The soil fungal community structure in the biochar treatment was significantly different from that in the straw treatment and control groups. Redundancy analysis (RDA) showed that soil fungal community structure was mainly affected by soil bulk density, C∶N, salinity, and TN. Secondly, compared with that in the control group, soil labile organic carbon (LOC) in the straw treatment group was significantly increased by 87.44% (P<0.05), whereas soil dissolved organic carbon (DOC) and microbial biomass carbon (MBC) in the biochar treatment group were significantly increased by 22.27% and 23.17% (P<0.05), respectively. Further, compared with that in the control group, the carbon pool activity (L) under straw treatment was significantly increased (P<0.05), and the carbon pool index (CPI) under biochar treatment was significantly increased (P<0.05). Spearman correlation analysis showed that the distribution characteristics of soil organic carbon active components were regulated by the dominant fungi. FUNGuild functional prediction results showed that saprophytic and its facultative nutritional fungi had an important impact on soil organic carbon active components and carbon pool management index after straw and biochar application.


Assuntos
Carbono , Carvão Vegetal , Fungos , Compostos Orgânicos , Caules de Planta , Microbiologia do Solo , Solo , Carvão Vegetal/química , Fungos/metabolismo , Solo/química , Caules de Planta/química , Caules de Planta/metabolismo , Fertilizantes
4.
Materials (Basel) ; 17(12)2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38930314

RESUMO

Polypropylene fiber reinforcement is an effective method to enhance the durability of concrete structures. With the increasing public interest in the widespread use of polypropylene fiber reinforced concrete (PFRC), the necessity of evaluating the mechanism of polypropylene fiber (PF) on the permeability of concrete has become prominent. This paper describes the influence of PF on the concrete permeability exposed to freeze-thaw cycles under compressive and tensile stress. The permeability of PFRC under compressive and tensile loads is accurately measured by a specialized permeability setup. The permeability of PFRC under compressive and tensile loads, the volume change of PFRC under compressive load, and the relationship between compressive stress levels at minimum permeability and minimum volume points of PFRC are discussed. The results indicate that the addition of PF adversely affects the permeability of concrete without freeze-thaw damage and cracks. However, it decreases the permeability of concrete specimens exposed to freeze-thaw cycles and cracking. Under compressive load, the permeability of PFRC initially decreases slowly and follows by a significant increase as the compressive stress level increases. This phenomenon correlates with the volume change of the specimen. The compressive stress level of the minimum permeability point and compressive stress level of the minimum volume point of PFRC exhibit a linear correlation, with a fitted proportional function parameter γ ≈ 0.98872. Under tensile load, the permeability of PFRC increases gradually with radial deformation and follows by a significant increase. The strain-permeability curves of PFRC under loading are studied and consist of two stages. In stage I, the permeability of PFRC gradually decreases with the increase of strain under compressive load, while the permeability increases with the increase of strain under tensile load. In stage II, under compressive load, the permeability of PFRC increases with the increase of freeze-thaw cycles, whereas under tensile load, the permeability gradually decreases with the increase of freeze-thaw cycles. The reduction of PF on the permeability of PFRC under tensile load is greater than that under compressive load. In future research, the relationship between strain and permeability of PFRC can be integrated with its constitutive relationship between stress and strain to provide a reference for the application of PF in the waterproofing of concrete structures.

5.
Sci Total Environ ; 945: 173861, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38871323

RESUMO

Coastal wetlands are key players in mitigating global climate change by sequestering soil organic matter. Soil organic matter consists of less stable particulate organic matter (POM) and more stable mineral-associated organic matter (MAOM). The distribution and drivers of MAOM and POM in coastal wetlands have received little attention, despite the processes and mechanisms differ from that in the upland soils. We explored the distribution of POM and MAOM, their contributions to SOM, and the controlling factors along a salinity gradient in an estuarine wetland. In the estuarine wetland, POM C and N were influenced by soil depth and vegetation type, whereas MAOM C and N were influenced only by vegetation type. In the estuarine wetland, SOM was predominantly in the form of MAOM (> 70 %) and increased with salinity (70 %-76 %), leading to long-term C sequestration. Both POM and MAOM increased with SOM, and the increase rate of POM was higher than that of MAOM. Aboveground plant biomass decreased with increasing salinity, resulted in a decrease in POM C (46 %-81 %) and N (52 %-82 %) pools. As the mineral amount and activity, and microbial biomass decreased, the MAOM C (2.5 %-64 %) and N pool (8.6 %-59 %) decreased with salinity. When evaluating POM, the most influential factors were microbial biomass carbon (MBC) and dissolved organic carbon (DOC). Key parameters, including MBC, DOC, soil salinity, soil water content, aboveground plant biomass, mineral content and activity, and bulk density, were identified as influencing factors for both MAOM abundance. Soil water content not only directly controlled MAOM, but together with salinity also indirectly regulated POM and MAOM by controlling microbial biomass and aboveground plant biomass. Our findings have important implications for improving the accumulation and increased stability of soil organic matter in coastal wetlands, considering the global sea level rise and increased frequency of inundation.

7.
Antiviral Res ; 227: 105905, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38740191

RESUMO

The rapid emergence of Severe Acute Respiratory Syndrome Coronavirus type 2 (SARS-CoV-2) variants, coupled with severe immune evasion and imprinting, has jeopardized the vaccine efficacy, necessitating urgent development of broad protective vaccines. Here, we propose a strategy employing recombinant rabies viruses (RABV) to create a universal SARS-CoV-2 vaccine expressing heterologous tandem receptor-binding domain (RBD) trimer from the SARS-CoV-2 Prototype, Delta, and Omicron strains (SRV-PDO). The results of mouse immunization indicated that SRV-PDO effectively induced cellular and humoral immune responses, and demonstrated higher immunogenicity and broader SARS-CoV-2 neutralization compared to the recombinant RABVs that only expressed RBD monomers. Moreover, SRV-PDO exhibited full protection against SARS-CoV-2 in the challenge assay. This study demonstrates that recombinant RABV expressing tandem RBD-heterotrimer as a multivalent immunogen could elicit a broad-spectrum immune response and potent protection against SARS-CoV-2, making it a promising candidate for future human or veterinary vaccines and offering a novel perspective in other vaccine design.


Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , Camundongos Endogâmicos BALB C , Vírus da Raiva , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Animais , Vírus da Raiva/imunologia , Vírus da Raiva/genética , Vacinas contra COVID-19/imunologia , Camundongos , SARS-CoV-2/imunologia , SARS-CoV-2/genética , COVID-19/prevenção & controle , COVID-19/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/sangue , Feminino , Humanos , Imunidade Humoral , Vetores Genéticos , Eficácia de Vacinas , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/genética , Vacinas Sintéticas/administração & dosagem
8.
Sci Rep ; 14(1): 10149, 2024 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-38698048

RESUMO

This study aims to investigate the potential impact of high-dose radiotherapy (RT) on brain structure, cognitive impairment, and the psychological status of patients undergoing brain tumor treatment. We recruited and grouped 144 RT-treated patients with brain tumors into the Low dose group (N = 72) and the High dose group (N = 72) according to the RT dose applied. Patient data were collected by using the HADS and QLQ-BN20 system for subsequent analysis and comparison. Our analysis showed no significant correlation between the RT doses and the clinicopathological characteristics. We found that a high dose of RT could aggravate cognitive impairment and deteriorate patient role functioning, indicated by a higher MMSE and worsened role functioning in the High dose group. However, the depression status, social functioning, and global health status were comparable between the High dose group and the Low dose group at Month 0 and Month 1, while being worsened in the High dose group at Month 3, indicating the potential long-term deterioration of depression status in brain tumor patients induced by high-dose RT. By comparing patient data at Month 0, Month 1, Month 3, Month 6, and Month 9 after RT, we found that during RT treatment, RT at a high dose could aggravate cognitive impairment in the short term and lead to worsened patient role functioning, and even deteriorate the overall psychological health status of patients in the long term.


Assuntos
Neoplasias Encefálicas , Disfunção Cognitiva , Humanos , Masculino , Feminino , Disfunção Cognitiva/etiologia , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/psicologia , Pessoa de Meia-Idade , Idoso , Encéfalo/efeitos da radiação , Encéfalo/patologia , Adulto , Dosagem Radioterapêutica , Depressão/etiologia , Qualidade de Vida
9.
J Craniofac Surg ; 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38809062

RESUMO

Despite their limitations, epidemiological studies provide information useful for formulating effective and efficient injury prevention strategies. The aim is to carry out an epidemiology study of maxillofacial fracture in Xijing Hospital. Level of Evidence: Level II-therapeutic study.

10.
PeerJ ; 12: e17032, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38770093

RESUMO

Purpose: This study seeks to identify potential clinical biomarkers for osteoarthritis (OA) using bioinformatics and investigate OA mechanisms through cellular assays. Methods: Differentially Expressed Genes (DEGs) from GSE52042 (four OA samples, four control samples) were screened and analyzed with protein-protein interaction (PPI) analysis. Overlapping genes in GSE52042 and GSE206848 (seven OA samples, and seven control samples) were identified and evaluated using Gene Set Enrichment Analysis (GSEA) and clinical diagnostic value analysis to determine the hub gene. Finally, whether and how the hub gene impacts LPS-induced OA progression was explored by in vitro experiments, including Western blotting (WB), co-immunoprecipitation (Co-IP), flow cytometry, etc. Result: Bioinformatics analysis of DEGs (142 up-regulated and 171 down-regulated) in GSE52042 identified two overlapping genes (U2AF2, TPX2) that exhibit significant clinical diagnostic value. These genes are up-regulated in OA samples from both GSE52042 and GSE206848 datasets. Notably, TPX2, which AUC = 0.873 was identified as the hub gene. In vitro experiments have demonstrated that silencing TPX2 can alleviate damage to chondrocytes induced by lipopolysaccharide (LPS). Furthermore, there is a protein interaction between TPX2 and MMP13 in OA. Excessive MMP13 can attenuate the effects of TPX2 knockdown on LPS-induced changes in OA protein expression, cell growth, and apoptosis. Conclusion: In conclusion, our findings shed light on the molecular mechanisms of OA and suggested TPX2 as a potential therapeutic target. TPX2 could promote the progression of LPS-induced OA by up-regulating the expression of MMP13, which provides some implications for clinical research.


Assuntos
Proteínas de Ciclo Celular , Condrócitos , Progressão da Doença , Lipopolissacarídeos , Metaloproteinase 13 da Matriz , Proteínas Associadas aos Microtúbulos , Osteoartrite , Regulação para Cima , Lipopolissacarídeos/farmacologia , Osteoartrite/genética , Osteoartrite/metabolismo , Osteoartrite/patologia , Osteoartrite/induzido quimicamente , Humanos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Metaloproteinase 13 da Matriz/metabolismo , Metaloproteinase 13 da Matriz/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Condrócitos/metabolismo , Condrócitos/patologia , Condrócitos/efeitos dos fármacos , Biologia Computacional , Mapas de Interação de Proteínas
11.
Plant Commun ; : 100934, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38689493

RESUMO

In angiosperms, the pollen tube enters the receptive synergid cell, where it ruptures to release its cytoplasm along with two sperm cells. This interaction is complex, and the exact signal transducers that trigger the bursting of pollen tubes are not well understood. In this study, we identify three homologous receptor-like cytoplasmic kinases (RLCKs) expressed in pollen tubes of Arabidopsis, Delayed Burst 1/2/3 (DEB1/2/3), which play a crucial role in this process. These genes produce proteins localized on the plasma membrane, and their knockout causes delayed pollen tube burst and entrance of additional pollen tubes into the embryo sac due to fertilization recovery. We show that DEBs interact with the Ca2+ pump ACA9, influencing the dynamics of cytoplasmic Ca2+ in pollen tubes through phosphorylation. These results highlight the importance of DEBs as key signal transducers and the critical function of the DEB-ACA9 axis in timely pollen tube burst in synergids.

12.
Materials (Basel) ; 17(8)2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38673091

RESUMO

This paper describes the effects of macro fibers on permeability and crack surface topography of layered fiber-reinforced concrete (FRC) specimens with different layering ratios under uniaxial tensile load. The crack permeability of layered FRC specimens is investigated by a self-designed permeability setup. The topographical analysis of crack surfaces is investigated by a custom-designed laser scanning setup. The results show that when the fiber volume content and layering ratio of the FRC layer are constant, the tensile toughness of layered FRC specimens depends on the proportion of steel fiber in macro fibers, and with an increase in the proportion of steel fiber, the tensile toughness of layered FRC specimens increases. For the layered FRC specimens, the crack permeability is much lower than that of the normal concrete (NC) specimen. A significant positive synergistic effect on crack impermeability can be achieved by the combination of steel fiber and polypropylene fiber in the SF80PP2.3 specimen. The crack surface roughness parameter (Rn) values of the NC layer in layered FRC specimens are all higher than those of the NC specimen, and the crack surface Rn of the FRC layer in layered FRC specimens is higher than that of the unlayered FRC specimens. This can effectively increase the head loss of cracks and reduce the crack permeability of layered FRC specimens.

13.
Materials (Basel) ; 17(8)2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38673176

RESUMO

This paper describes hybrid fiber's influence on the crack permeability of cracked concrete exposed to freeze-thaw cycles. A permeability setup and a laser-scanning setup have been designed to measure the crack permeability and the fractured surface roughness of cracked hybrid fiber-reinforced concrete, containing polypropylene fiber and steel fiber, under a splitting tensile load. The results show that, when the effective crack width of the specimens is less than 25 µm, the rough crack surface significantly reduces the concrete's crack permeability. As the crack width increases, the effect of the concrete crack surface on crack permeability gradually decreases, and the crack permeability of the concrete is closer to the Poiseuille flow model. The permeability parameter α derived from the Poiseuille flow model is effective for assessing the crack permeability of concrete. Compared to the modified factor ξ of crack permeability, the permeability parameter α can effectively evaluate and quantify the development trend of crack permeability within a certain range of crack widths. The permeability parameter α of SF20PP2.3, subjected to the same freeze-thaw cycles, decreases by 16.3-94.8% compared to PP4.6 and SF40, and SF20PP2.3 demonstrates a positive synergistic effect on the crack impermeability of cracked concrete. The crack impermeability of SF40PP2.3, subjected to the same freeze-thaw cycles, lies between that of PP6.9 and SF60. The roughness of crack surface (X) and the crack permeability (Y) are highly correlated and follow an exponential curve (Y = 1.0415 × 107·e-6.025·X) in concrete. This demonstrates that hybrid fibers enhance crack impermeability by increasing the crack surface roughness. Furthermore, the combination of polypropylene fiber and steel fiber effectively promotes the formation of micro-cracks and facilitates the propagation of multiple cracks in the concrete matrix. This combination increases the head loss of water flow through the concrete and decreases the crack permeability.

14.
Opt Express ; 32(6): 8723-8735, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38571123

RESUMO

In this study, a Si defect structure was added into the silica network in order to activate the bismuth and silica structure active center. TD-DFT theoretical simulations show that the Bi and Si ODC(I) models can excite the active center of the E-band at 1408 nm. Additionally, the Bi-doped silica fiber (BDSF) with improved fluorescence was fabricated using atomic layer deposition (ALD) combined with the modified chemical vapor deposition (MCVD) technique. Some tests were used to investigate the structural and optical properties of BDSF. The UV-VIS spectral peak of the BDSF preform is 424 cm-1, and the binding energy of XPS is 439.3 eV, indicating the presence of Bi° atom in BDSF. The Raman peak near 811 cm-1 corresponds to the Bi-O bond. The Si POL defect lacks a Bi-O structure, and the reason for the absence of simulated active center from the E-band is explained. A fluorescence spectrometer was used to analyze the emission peak of a BDSF at 1420 nm. The gain of the BDSF based optical amplifier was measured 28.8 dB at 1420 nm and confirmed the effective stimulation of the bismuth active center in the E-band.

15.
Opt Express ; 32(6): 8937-8949, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38571139

RESUMO

In this study, PbS/Er co-doped fibers (PEDFs) were fabricated by atomic layer deposition (ALD) combined with modified chemical vapor deposition (MCVD). A pumping scheme based on two-photon absorption at 1310 nm of PEDF is proposed for L + band amplification. Through the theoretical analysis, the local environment of Er3+ is changed due to the co-doping of PbS, which improves the two-photon absorption efficiency near 1300 nm. Compared with the 980 nm pump, the PEDFs excited by the 1310 nm pump show better amplification performance in the L + band. And in a bi-directional pumping system, PEDF achieves over 22 dB of gain in the whole L band. In particular, the bandwidth of over 20 dB gain was extended to 1627 nm with a noise figure as low as 4.9 dB. To the best of our knowledge, this is the first time that a high-gain bandwidth of L band amplification has been extended to 1627 nm. The results of unsaturated loss also show that PbS co-doping improves the two-photon absorption efficiency of PEDF to broaden the amplification bandwidth of L + band. These results demonstrate that an effective L + band amplification method is practically provided for future ultra-wideband optical communications.

16.
Virol Sin ; 39(3): 434-446, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38556051

RESUMO

The Ebola virus (EBOV) is a member of the Orthoebolavirus genus, Filoviridae family, which causes severe hemorrhagic diseases in humans and non-human primates (NHPs), with a case fatality rate of up to 90%. The development of countermeasures against EBOV has been hindered by the lack of ideal animal models, as EBOV requires handling in biosafety level (BSL)-4 facilities. Therefore, accessible and convenient animal models are urgently needed to promote prophylactic and therapeutic approaches against EBOV. In this study, a recombinant vesicular stomatitis virus expressing Ebola virus glycoprotein (VSV-EBOV/GP) was constructed and applied as a surrogate virus, establishing a lethal infection in hamsters. Following infection with VSV-EBOV/GP, 3-week-old female Syrian hamsters exhibited disease signs such as weight loss, multi-organ failure, severe uveitis, high viral loads, and developed severe systemic diseases similar to those observed in human EBOV patients. All animals succumbed at 2-3 days post-infection (dpi). Histopathological changes indicated that VSV-EBOV/GP targeted liver cells, suggesting that the tissue tropism of VSV-EBOV/GP was comparable to wild-type EBOV (WT EBOV). Notably, the pathogenicity of the VSV-EBOV/GP was found to be species-specific, age-related, gender-associated, and challenge route-dependent. Subsequently, equine anti-EBOV immunoglobulins and a subunit vaccine were validated using this model. Overall, this surrogate model represents a safe, effective, and economical tool for rapid preclinical evaluation of medical countermeasures against EBOV under BSL-2 conditions, which would accelerate technological advances and breakthroughs in confronting Ebola virus disease.


Assuntos
Modelos Animais de Doenças , Ebolavirus , Doença pelo Vírus Ebola , Mesocricetus , Animais , Doença pelo Vírus Ebola/virologia , Doença pelo Vírus Ebola/patologia , Ebolavirus/genética , Ebolavirus/patogenicidade , Feminino , Humanos , Vesiculovirus/genética , Vesiculovirus/patogenicidade , Anticorpos Antivirais/sangue , Cricetinae , Carga Viral , Glicoproteínas/genética , Glicoproteínas/imunologia
17.
Int J Biol Macromol ; 264(Pt 2): 130820, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38484812

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its variants has resulted in global economic losses and posed a threat to human health. The pandemic highlights the urgent need for an efficient, easily producible, and broad-spectrum vaccine. Here, we present a potentially universal strategy for the rapid and general design of vaccines, focusing on the design and testing of omicron BA.5 RBD-conjugated self-assembling ferritin nanoparticles (NPs). The covalent bonding of RBD-Fc to protein A-ferritin was easily accomplished through incubation, resulting in fully multivalent RBD-conjugated NPs that exhibited high structural uniformity, stability, and efficient assembly. The ferritin nanoparticle vaccine synergistically stimulated the innate immune response, Tfh-GCB-plasma cell-mediated activation of humoral immunity and IFN-γ-driven cellular immunity. This nanoparticle vaccine induced a high level of cross-neutralizing responses and protected golden hamsters challenged with multiple mutant strains from infection-induced clinical disease, providing a promising strategy for broad-spectrum vaccine development for SARS-CoV-2 prophylaxis. In conclusion, the nanoparticle conjugation platform holds promise for its potential universality and competitive immunization efficacy and is expected to facilitate the rapid manufacturing and broad application of next-generation vaccines.


Assuntos
COVID-19 , Nanopartículas , Animais , Cricetinae , Humanos , SARS-CoV-2 , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Imunidade Inata , Ferritinas/genética , Nanovacinas , Anticorpos Neutralizantes , Anticorpos Antivirais
18.
Antiviral Res ; 225: 105854, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38447647

RESUMO

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with frequent mutations has seriously damaged the effectiveness of the 2019 coronavirus disease (COVID-19) vaccine. There is an urgent need to develop a broad-spectrum vaccine while elucidating the underlying immune mechanisms. Here, we developed a SARS-CoV-2 virus-like particles (VLPs) vaccine based on the Canarypox-virus vector (ALVAC-VLPs) using CRISPR/Cas9. Immunization with ALVAC-VLPs showed the effectively induce SARS-CoV-2 specific T and B cell responses to resist the lethal challenge of mouse adaptive strains. Notably, ALVAC-VLPs conferred protection in golden hamsters against SARS-CoV-2 Wuhan-Hu-1 (wild-type, WT) and variants (Beta, Delta, Omicron BA.1, and BA.2), as evidenced by the prevention of weight loss, reduction in lung and turbinate tissue damage, and decreased viral load. Further investigation into the mechanism of immune response induced by ALVAC-VLPs revealed that toll-like receptor 4 (TLR4) mediates the recruitment of dendritic cells (DCs) to secondary lymphoid organs, thereby initiating follicle assisted T (Tfh) cell differentiation, the proliferation of germinal center (GC) B cells and plasma cell production. These findings demonstrate the immunogenicity and efficacy of the safe ALVAC-VLPs vaccine against SARS-CoV-2 and provide valuable insight into the development of COVID-19 vaccine strategies.


Assuntos
COVID-19 , Vacinas de Partículas Semelhantes a Vírus , Camundongos , Animais , Humanos , SARS-CoV-2 , Vacinas contra COVID-19 , Sistemas CRISPR-Cas , Edição de Genes , Anticorpos Antivirais , Anticorpos Neutralizantes
19.
Sci Total Environ ; 925: 171767, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38499102

RESUMO

Soil water conditions are known to influence soil nutrient availability, but the specific impact of different conditions on soil phosphorus (P) availability through the modulation of P-cycling functional microbial communities in hyper-arid desert ecosystems remains largely unexplored. To address this knowledge gap, we conducted a 3-year pot experiment using a typical desert plant species (Alhagi sparsifolia Shap.) subjected to two water supply levels (25 %-35 % and 65 %-75 % of maximum field capacity, MFC) and four P-supply levels (0, 1, 3, and 5 g P m-2 y-1). Our investigation focused on the soil Hedley-P pool and the four major microbial groups involved in the critical phases of soil microbial P-cycling. The results revealed that the drought (25 %-35 % MFC) and no P-supply treatments reduced soil resin-P and NaHCO3-Pi concentrations by 87.03 % and 93.22 %, respectively, compared to the well-watered (65 %-75 % MFC) and high P-supply (5 g P m-2 y-1) treatments. However, the P-supply treatment resulted in a 12 %-22 % decrease in the soil NH4+-N concentration preferred by microbes compared to the no P-supply treatment. Moreover, the abundance of genes engaged in microbial P-cycling (e.g. gcd and phoD) increased under the drought and no P-supply treatments (p < 0.05), suggesting that increased NH4+-N accumulation under these conditions may stimulate P-solubilizing microbes, thereby promoting the microbial community's investment in resources to enhance the P-cycling potential. Furthermore, the communities of Steroidobacter cummioxidans, Mesorhizobium alhagi, Devosia geojensis, and Ensifer sojae, associated with the major P-cycling genes, were enriched in drought and no or low-P soils. Overall, the drought and no or low-P treatments stimulated microbial communities and gene abundances involved in P-cycling. However, this increase was insufficient to maintain soil P-bioavailability. These findings shed light on the responses and feedback of microbial-mediated P-cycling behaviors in desert ecosystems under three-year drought and soil P-deficiency.


Assuntos
Ecossistema , Microbiota , Solo , Secas , Microbiologia do Solo , Plantas
20.
Glob Chang Biol ; 30(3): e17213, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38436125

RESUMO

Paddy fields serve as significant reservoirs of soil organic carbon (SOC) and their potential for terrestrial carbon (C) sequestration is closely associated with changes in SOC pools. However, there has been a dearth of comprehensive studies quantifying changes in SOC pools following extended periods of rice cultivation across a broad geographical scale. Using 104 rice paddy sampling sites that have been in continuous cultivation since the 1980s across China, we studied the changes in topsoil (0-20 cm) labile organic C (LOC I), semi-labile organic C (LOC II), recalcitrant organic C (ROC), and total SOC. We found a substantial increase in both the content (48%) and density (39%) of total SOC within China's paddy fields between the 1980s to the 2010s. Intriguingly, the rate of increase in content and density of ROC exceeded that of LOC (I and II). Using a structural equation model, we revealed that changes in the content and density of total SOC were mainly driven by corresponding shifts in ROC, which are influenced both directly and indirectly by climatic and soil physicochemical factors; in particular temperature, precipitation, phosphorous (P) and clay content. We also showed that the δ13 CLOC were greater than δ13 CROC , independent of the rice cropping region, and that there was a significant positive correlation between δ13 CSOC and δ13 Cstraw . The δ13 CLOC and δ13 CSOC showed significantly negative correlation with soil total Si, suggesting that soil Si plays a part in the allocation of C into different SOC pools, and its turnover or stabilization. Our study underscores that the global C sequestration of the paddy fields mainly stems from the substantial increase in ROC pool.


Assuntos
Oryza , Solo , Carbono , China , Geografia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA