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1.
J Am Chem Soc ; 146(7): 4632-4641, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38340061

RESUMO

As fuel and an important chemical feedstock, n-propanol is highly desired in electrochemical CO2/CO reduction on Cu catalysts. However, the precise regulation of the Cu localized structure is still challenging and poorly understood, thus hindering the selective n-propanol electrosynthesis. Herein, by decorating Au nanoparticles (NPs) on CuO nanosheets (NSs), we present a counterintuitive transformation of CuO into undercoordinated Cu sites locally around Au NPs during CO reduction. In situ spectroscopic techniques reveal the Au-steered formation of abundant undercoordinated Cu sites during the removal of oxygen on CuO. First-principles accuracy molecular dynamic simulation demonstrates that the localized Cu atoms around Au tend to rearrange into disordered layer rather than a Cu (111) close-packed plane observed on bare CuO NSs. These Au-steered undercoordinated Cu sites facilitate CO binding, enabling selective electroreduction of CO into n-propanol with a high Faradaic efficiency of 48% in a flow cell. This work provides new insight into the regulation of the oxide-derived catalysts reconstruction with a secondary metal component.

2.
J Am Chem Soc ; 146(23): 16039-16051, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38832517

RESUMO

Efficient methane photooxidation to formic acid (HCOOH) has emerged as a sustainable approach to simultaneously generate value-added chemicals and harness renewable energy. However, the persistent challenge lies in achieving a high yield and selectivity for HCOOH formation, primarily due to the complexities associated with modulating intermediate conversion and desorption after methane activation. In this study, we employ first-principles calculations as a comprehensive guiding tool and discover that by precisely controlling the O2 activation process on noble metal cocatalysts and the adsorption strength of carbon-containing intermediates on metal oxide supports, one can finely tune the selectivity of methane photooxidation products. Specifically, a bifunctional catalyst comprising Pd nanoparticles and monoclinic WO3 (Pd/WO3) would possess optimal O2 activation kinetics and an intermediate oxidation/desorption barrier, thereby promoting HCOOH formation. As evidenced by experiments, the Pd/WO3 catalyst achieves an exceptional HCOOH yield of 4.67 mmol gcat-1 h-1 with a high selectivity of 62% under full-spectrum light irradiation at room temperature using molecular O2. Notably, these results significantly outperform the state-of-the-art photocatalytic systems operated under identical condition.

3.
Biofouling ; : 1-11, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39212053

RESUMO

To improve the durability of the photobioreactor antibiofouling surface for microalgal cultivation, a series of photoreactive poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA) were successfully synthesized and used to modify ethylene-vinyl acetate (EVA) films by a surface coating and UV light grafting method. Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy analysis (XPS) and fluorescence microscopy results indicated that PTFEMA were fixed successfully onto the EVA film surface through a covalent bond. During the microalgal adhesion assay, the number of EVA-PTFEMA film-adhered microalgae was 41.4% lower than that of the EVA film. Moreover, the number of microalgae attached to the EVA-PTFEMA film decreased by 61.7% after cleaning, while that of EVA film decreased by only 49.1%. It was found that the contact angle of EVA-PTFEMA film surface increased, and remained stable when immersed in acid and alkali solution for up to 90 days. HIGHLIGHTSDurable photobioreactor antibiofouling surfaces for microalgal cultivation were prepared successfully.The contact angle of antibiofouling coating surface remained stable in acid and base environment for 90 days.The attached microalgae on antibiofouling surface decreased 41.4% than those of unmodified surface.The attached microalgae on antibiofouling surface could be cleaned by 61.7% through changing the flow velocity of microalgal suspension.

4.
Angew Chem Int Ed Engl ; 63(24): e202404658, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38573117

RESUMO

Efficiently converting methane into valuable chemicals via photocatalysis under mild condition represents a sustainable route to energy storage and value-added manufacture. Despite continued interest in this area, the achievements have been overshadowed by the absence of standardized protocols for conducting photocatalytic methane oxidation experiments as well as evaluating the corresponding performance. In this review, we present a structured solution aimed at addressing these challenges. Firstly, we introduce the norms underlying reactor design and outline various configurations in the gas-solid and gas-solid-liquid reaction systems. This discussion helps choosing the suitable reactors for methane conversion experiments. Subsequently, we offer a comprehensive step-by-step protocol applicable to diverse methane-conversion reactions. Emphasizing meticulous verification and accurate quantification of the products, this protocol highlights the significance of mitigating contamination sources and selecting appropriate detection methods. Lastly, we propose the standardized performance metrics crucial for evaluating photocatalytic methane conversion. By defining these metrics, the community could obtain the consensus of assessing the performance across different studies. Moving forward, the future of photocatalytic methane conversion necessitates further refinement of stringent experimental standards and evaluation criteria. Moreover, development of scalable reactor is essential to facilitate the transition from laboratory proof-of-concept to potentially industrial production.

5.
J Am Chem Soc ; 145(4): 2698-2707, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36649534

RESUMO

Selective CH4 oxidation to CH3OH or HCHO with O2 in H2O under mild conditions provides a desired sustainable pathway for synthesis of commodity chemicals. However, manipulating reaction selectivity while maintaining high productivity remains a huge challenge due to the difficulty in the kinetic control of the formation of a desired oxygenate against its overoxidation. Here, we propose a highly efficient strategy, based on the precise control of the type of as-formed radicals by rational design on photocatalysts, to achieve both high selectivity and high productivity of CH3OH and HCHO in CH4 photooxidation for the first time. Through tuning the band structure and the size of active sites (i.e., single atoms or nanoparticles) in our Au/In2O3 catalyst, we show alternative formation of two important radicals, •OOH and •OH, which leads to distinctly different reaction paths to the formation of CH3OH and HCHO, respectively. This approach gives rise to a remarkable HCHO selectivity and yield of 97.62% and 6.09 mmol g-1 on In2O3-supported Au single atoms (Au1/In2O3) and an exceptional CH3OH selectivity and yield of 89.42% and 5.95 mmol g-1 on In2O3-supported Au nanoparticles (AuNPs/In2O3), respectively, upon photocatalytic CH4 oxidation for 3 h at room temperature. This work opens a new avenue toward efficient and selective CH4 oxidation by delicate design of composite photocatalysts.

6.
Angew Chem Int Ed Engl ; 62(52): e202315478, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-37946688

RESUMO

Photoelectrochemistry is becoming an innovative approach to organic synthesis. Generally, the current photoelectrocatalytic organic transformations suffer from limited reaction type, low conversion efficiency and poor stability. Herein, we develop efficient and stable photoelectrode materials using metal oxide protective layer, with a focus on achieving regioselective activation of amine compounds. Notably, our photoelectrochemistry process is implemented under mild reaction conditions and does not involve any directing groups, transition metals or oxidants. The results demonstrate that beyond photocatalysis and electrocatalysis, photoelectrocatalysis exhibits high efficiency, remarkable repeatability and good functional group tolerance, highlighting its great potential for applications.

7.
J Am Chem Soc ; 144(35): 15977-15987, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-35969152

RESUMO

Photocatalytic conversion of methane to value-added products under mild conditions, which represents a long sought-after goal for industrial sustainable production, remains extremely challenging to afford high production and selectivity using cheap catalysts. Herein, we present the crystal phase engineering of commercially available anatase TiO2 via simple thermal annealing to optimize the structure-property correlation. A biphase catalyst with anatase (90%) and rutile (10%) TiO2 with the optimal phase interface concentration exhibits exceptional performance in the oxidation of methane to formaldehyde under the reaction conditions of water solvent, oxygen atmosphere, and full-spectrum light irradiation. An unprecedented production of 24.27 mmol gcat-1 with an excellent selectivity of 97.4% toward formaldehyde is acquired at room temperature after a 3 h reaction. Both experimental results and theoretical calculations disclose that the crystal phase engineering of TiO2 lengthens the lifetime of photogenerated carriers and favors the formation of intermediate methanol species, thus maximizing the efficiency and selectivity in the aerobic oxidation of methane to formaldehyde. More importantly, the feasibility of the scale-up production of formaldehyde is demonstrated by inventing a "pause-flow" reactor. This work opens the avenue toward industrial methane transformation in a sustainable and economical way.

8.
Angew Chem Int Ed Engl ; 60(11): 5811-5815, 2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33169485

RESUMO

Direct methane oxidation into value-added organic oxygenates with high productivity under mild condition remains a great challenge. We show Fe-O clusters on nodes of metal-organic frameworks (MOFs) with tunable electronic state for direct methane oxidation into C1 organic oxygenates at 50 °C. The Fe-O clusters are grafted onto inorganic Zr6 nodes of UiO-66, while the organic terephthalic acid (H2 BDC) ligands of UiO-66 are partially substituted with monocarboxylic modulators of acetic acid (AA) or trifluoroacetic acid (TFA). Experiments and theoretical calculation disclose that the TFA group coordinated with Zr6 node of UiO-66 enhances the oxidation state of adjacent Fe-O cluster due to its electron-withdrawing ability, promotes the activation of C-H bond of methane, and increases its selective conversion, thus leading to the extraordinarily high C1 oxygenate yield of 4799 µmol gcat -1 h-1 with 97.9 % selectivity, circa 8 times higher than those modulated with AA.

9.
Small ; 16(15): e1902860, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31468709

RESUMO

In situ monitoring of hydrogen peroxide (H2 O2 ) during its production process is needed. Here, an electrochemical H2 O2 sensor with a wide linear current response range (concentration: 5 × 10-8 to 5 × 10-2 m), a low detection limit (32.4 × 10-9 m), and a high sensitivity (568.47 µA mm-1 cm-2 ) is developed. The electrocatalyst of the sensor consists of cobalt nanoparticles and atomic Co-Nx moieties anchored on nitrogen doped carbon nanotube arrays (Co-N/CNT), which is obtained through the pyrolysis of the sandwich-like urea@ZIF-67 complex. More cobalt nanoparticles and atomic Co-Nx as active sites are exposed during pyrolysis, contributing to higher electrocatalytic activity. Moreover, a portable screen-printed electrode sensor is constructed and demonstrated for rapidly detecting (cost ≈40 s) H2 O2 produced in microbial fuel cells with only 50 µL solution. Both the synthesis strategy and sensor design can be applied to other energy and environmental fields.

10.
Mikrochim Acta ; 185(11): 501, 2018 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-30302565

RESUMO

Core-shell structured particles were prepared from carbonized zeolitic imidazolate frameworks (ZIFs) and reduced graphene oxide (rGO). The particles possess a nitrogen content of up to 10.6%. The loss of nitrogen from the ZIF is avoided by utilizing the reduction and agglomeration of graphene oxide with suitable size (>2 µm) during pyrolysis. The resulting carbonized ZIF@rGO particles were deposited on a glassy carbon electrode to give an amperometric sensor for H2O2, typically operated at a voltage of -0.4 V (vs. Ag/AgCl). The sensor has a wide detection range (from 5 × 10-6 to 2 × 10-2 M), a 3.3 µM (S/N = 3) detection limit and a 0.272 µA·µM-1·cm-2 sensitivity, much higher than that of directly carbonized ZIFs. The sensor material was also deposited on a screen-printed electrode to explore the possibility of application. Graphical abstract Nitrogen doped carbon (NC) derived from carbonized zeolitic imidazolate frameworks is limited because of low nitrogen content. Here, nitrogen-rich NC@reduced graphene oxide (rGO) core-shell structured particles are described. The NC@rGO particles show distinctly better H2O2 detection performance than NC.

11.
Carbohydr Polym ; 342: 122362, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39048191

RESUMO

Cellulose possesses numerous favorable peculiarities to replace petroleum-based materials. Nevertheless, the extremely high hygroscopicity of cellulose severely degrades their mechanical performance, which is a major obstacle to the production of high-strength, multi-functional cellulose-based materials. In this work, a simple strategy was proposed to fabricate durable versatile nanocellulose films based on sustaining CO2 capture and in-situ calcification. In this strategy, Ca(OH)2 was in-situ formed on the films by Ca2+ crosslinking and subsequent introduction of OH-, which endowed the films with high mechanical strength and carbon sequestration ability. The following CO2 absorption process continuously improved the water resistance and durability of the films, and enabled them to maintain excellent mechanical properties and promising light management ability. After a 30-day CO2 absorption process, the water contact angle of the films can be increased from 43° to 79°, and the weight gain rate of the films in a 30 h water-absorption process can be sharply decreased from 331.2 % to 52.2 %. The films could maintain a high tensile strength of 340 MPa, and result in a CO2 absorption rate of 3.5 mmol/gcellulose after 30 days. In this study, the improvement of durability and carbon sequestration of nanocellulose films was achieved by a simple and effective method.

12.
Anal Methods ; 16(30): 5304-5310, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39028021

RESUMO

Protein glycosylation plays a crucial role in various biological processes and is related to various diseases. Highly specific enrichment of glycopeptides before mass spectrometry detection is crucial for comprehensive glycoproteomic analysis. However, it still remains a great challenge due to the absence of affinity materials with excellent enrichment efficiency. In this work, a triazine structure linked by a -NH- bond of two-dimensional (2-D) covalent organic framework (COF) nanosheets was synthesized as an affinity adsorbent for the selective capture of glycopeptides. In particular, by introducing hydrophilic monomers via a bottom-up approach, the 2-D COF (denoted as NENP-1) nanosheets were provided with abundant amino groups and inherent hydrophilicity. Owing to the specific surface area and excessive accessible sites for hydrophilicity, the resulting NENP-1 nanosheets exhibited an outstanding glycopeptide enrichment efficiency from standard samples with a superior detection sensitivity (1 × 10-10 M), good enrichment selectivity (1 : 800, HRP tryptic digest to BSA protein), excellent binding capacity (100 mg g-1), great reusability, and recovery (60.2%). Furthermore, using the NENP-1 nanosheet adsorbent, twenty-four endogenous glycopeptides in the serum of patients with gastric cancer were successfully identified by LC-MS/MS technology, which illustrates a promising prospective of hydrophilic COF nanosheets in glycoproteomics research.


Assuntos
Glicopeptídeos , Interações Hidrofóbicas e Hidrofílicas , Nanoestruturas , Triazinas , Glicopeptídeos/química , Glicopeptídeos/sangue , Glicopeptídeos/análise , Humanos , Nanoestruturas/química , Triazinas/química , Glicosilação , Estruturas Metalorgânicas/química , Espectrometria de Massas em Tandem/métodos
13.
Nanomicro Lett ; 16(1): 85, 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38214822

RESUMO

Electromagnetic interference shielding (EMI SE) modules are the core component of modern electronics. However, the traditional metal-based SE modules always take up indispensable three-dimensional space inside electronics, posing a major obstacle to the integration of electronics. The innovation of integrating 3D-printed conformal shielding (c-SE) modules with packaging materials onto core electronics offers infinite possibilities to satisfy ideal SE function without occupying additional space. Herein, the 3D printable carbon-based inks with various proportions of graphene and carbon nanotube nanoparticles are well-formulated by manipulating their rheological peculiarity. Accordingly, the free-constructed architectures with arbitrarily-customized structure and multifunctionality are created via 3D printing. In particular, the SE performance of 3D-printed frame is up to 61.4 dB, simultaneously accompanied with an ultralight architecture of 0.076 g cm-3 and a superhigh specific shielding of 802.4 dB cm3 g-1. Moreover, as a proof-of-concept, the 3D-printed c-SE module is in situ integrated into core electronics, successfully replacing the traditional metal-based module to afford multiple functions for electromagnetic compatibility and thermal dissipation. Thus, this scientific innovation completely makes up the blank for assembling carbon-based c-SE modules and sheds a brilliant light on developing the next generation of high-performance shielding materials with arbitrarily-customized structure for integrated electronics.

14.
Biochim Biophys Acta Mol Cell Res ; 1871(2): 119620, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37926157

RESUMO

Fibroblast growth factor 21 (FGF21) is a key regulator of energy metabolism. Recent studies suggested that serum FGF21 levels increase with declining renal function. However, the link between FGF21 and kidney diseases and the direct effect of FGF21 in renal fibrosis remains unclear. In this study, FGF21 was upregulated in unilateral ureteral obstruction (UUO)-induced renal fibrosis and cellular fibrosis induced by transforming growth factor-ß, and renal expression of FGF21 was positively correlated with fibrosis markers. Additionally, FGF21 was regulated by Wnt/ß-catenin signaling pathway. The knockdown and overexpression of FGF21 in mouse tubular epithelial cells demonstrated that FGF21 alleviates renal fibrosis by inhibiting the Wnt/ß-catenin signaling pathway. To investigate the effect of FGF21 on renal fibrosis in vivo, we established an overexpression model by injecting the plasmid in mice and found that FGF21 overexpression relieved UUO-induced renal fibrosis and renal inflammatory response. Taken together, FGF21 is upregulated with the activation of Wnt/ß-catenin signaling pathway and alleviates renal fibrosis by inhibiting the activation of Wnt/ß-catenin signaling pathway in a negative feedback mode. These results provide a new understanding for the source of elevated serum FGF21 in patients with chronic kidney disease and prove that FGF21 is a direct inhibitor of the progression of renal fibrosis, thus providing novel therapeutic intervention insights for renal fibrosis.


Assuntos
Fatores de Crescimento de Fibroblastos , Nefropatias , Obstrução Ureteral , Humanos , Camundongos , Animais , Obstrução Ureteral/complicações , Obstrução Ureteral/metabolismo , Via de Sinalização Wnt , Nefropatias/genética , Nefropatias/metabolismo , Fibrose
15.
Int J Biol Macromol ; 279(Pt 4): 135490, 2024 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-39255882

RESUMO

Wastewater purification has evolved into a global problem in the face of increasing scarcity of freshwater resources. Photocatalysis technology possesses prominent advantages in treating pollutants in water because of its low cost and mild reaction conditions, which provides an effective way to treat multiple pollutants and reduce membrane fouling. Herein, we combine photocatalysis technology with filtration technology via in situ reduction Bi0 with Bi2SiO5 strategy incorporating a carbonized wood filter to synthesize carbon/Bi2SiO5@Bi bi-functional composite. Thus, simultaneous filtration and photocatalytic degradation of Rhodamine B and tetracycline were achieved. After filtrating for 30 min, the degradation rate of RhB and TC were 94.23 % and 81.39 %, respectively. Especially, the flux of RhB and TC were up to 2162.16 L m-2 h-1 and 1811.32 L m-2 h-1. In addition, the composite filter also has good recyclability and reusability, after 5 cycles, the degradation efficiency of RhB remains at 91 %. This study utilized photocatalytic technology combined with membrane filtration technology to successfully solve the contradiction between catalytic efficiency and water flux, which realized rapid and dynamic removal of organic pollutants from water. Besides, the use of carbonized wood-based materials provides a potential biomass technology for the preparation of bifunctional photocatalytic filters.

16.
Nat Commun ; 15(1): 6907, 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39134536

RESUMO

Photoelectrochemical (PEC) cell is an ideal platform for organic transformation because of its green benefits and minimal energy consumption. As an emerging methodology, the reaction types of photoelectrocatalytic organic synthesis (PECOS) are limited to simple oxidation and C-H activation at current stage. Metal catalysis for the construction of C(sp2)-N bonds has not been touched yet in PECOS. We introduce here a PEC method that successfully engages Ni catalysis for the mild production of aniline derivatives. Experimental and computational investigations elucidate that the addition of photoanode-generated amine radical to Ni catalyst avoids the sluggish nucleophilic attack, enabling the reaction to proceed at an ultra-low potential (-0.4 V vs. Ag/AgNO3) and preventing the overoxidation of products in conventional electrochemical synthesis. This synergistic catalysis strategy exhibits good functional group tolerance and wide substrate scope on both aryl halides and amines, by which some important natural products and pharmaceutical chemicals have been successfully modified.

17.
Nat Commun ; 15(1): 4679, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38824163

RESUMO

Tungsten trioxide (WO3) has been recognized as the most promising photocatalyst for highly selective oxidation of methane (CH4) to formaldehyde (HCHO), but the origin of catalytic activity and the reaction manner remain controversial. Here, we take {001} and {110} facets dominated WO3 as the model photocatalysts. Distinctly, {001} facet can readily achieve 100% selectivity of HCHO via the active site mechanism whereas {110} facet hardly guarantees a high selectivity of HCHO along with many intermediate products via the radical way. In situ diffuse reflectance infrared Fourier transform spectroscopy, electron paramagnetic resonance and theoretical calculations confirm that the competitive chemical adsorption between CH4 and H2O and the different CH4 activation routes on WO3 surface are responsible for diverse CH4 oxidation pathways. The microscopic mechanism elucidation provides the guidance for designing high performance photocatalysts for selective CH4 oxidation.

18.
Tissue Cell ; 90: 102506, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39096791

RESUMO

Myoblast is a kind of activated muscle stem cell. Its biological activities, such as proliferation, migration, differentiation, and fusion, play a crucial role in maintaining the integrity of the skeletal muscle system. These activities of myoblasts can be significantly influenced by the extracellular matrix. Collagen, being a principal constituent of the extracellular matrix, substantially influences these biological activities. In skeletal muscle, collagen I and III are two kinds of primary collagen types. Their influence on myoblasts and the difference between them remain ambiguous. The purpose of this study is to discover the influence of collagen I and III on biological function of myoblasts and compare their differences. We used C2C12 cell line and primary myoblasts to discover the effect of collagen I and III on proliferation, migration and differentiation of myoblasts and then performed the transcriptome sequencing and analysis. The results showed that both collagen I and III enhanced the proliferation of myoblasts, with no statistical difference between them. Similarly, collagen I and III enhanced the migration of myoblasts, with collagen I was more pronounced in Transwell assay. On the contrary, collagen I and III inhibited myoblasts differentiation, with collagen III was more pronounced at gene expression level. The transcriptome sequencing identified DEGs and enrichment analysis elucidated different terms between Type I and III collagen. Collectively, our research preliminarily elucidated the influence of collagen I and III on myoblasts and their difference and provided the preliminary experimental foundation for subsequent research.


Assuntos
Diferenciação Celular , Movimento Celular , Proliferação de Células , Colágeno Tipo I , Mioblastos , Diferenciação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Mioblastos/citologia , Mioblastos/metabolismo , Animais , Camundongos , Colágeno Tipo I/metabolismo , Colágeno Tipo III/metabolismo , Colágeno Tipo III/genética , Linhagem Celular
19.
Sci Total Environ ; 912: 169568, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38143001

RESUMO

Constructed wetlands (CWs) are a cost-effective and environmentally friendly wastewater treatment technology. The influent chemical oxygen demand (COD)/nitrogen (N) ratio (CNR) plays a crucial role in microbial activity and purification performance. However, the effects of CNR changes on microbial diversity, interactions, and assembly processes in CWs are not well understood. In this study, we conducted comprehensive mechanistic experiments to investigate the response of CWs to changes in influent CNR, focusing on the effluent, rhizosphere, and substrate microbiota. Our goal is to provide new insights into CW management by integrating microbial ecology and environmental engineering perspectives. We constructed two groups of horizontal subsurface flow constructed wetlands (HFCWs) and set up three influent CNRs to analyse the microbial responses and nutrient removal. The results indicated that increasing influent CNR led to a decrease in microbial α-diversity and niche width. Genera involved in nitrogen removal and denitrification, such as Rhodobacter, Desulfovibrio, and Zoogloea, were enriched under medium/high CNR conditions, resulting in higher nitrate (NO3--N) removal (up to 99 %) than that under lower CNR conditions (<60 %). Environmental factors, including water temperature (WT), pH, and phosphorus (P), along with CNR-induced COD and NO3--N play important roles in microbial succession in HFCWs. The genus Nitrospira, which is involved in nitrification, exhibited a significant negative correlation (p < 0.05) with WT, COD, and P. Co-occurrence network analysis revealed that increasing influent CNR reduced the complexity of the network structure and increased microbial competition. Analysis using null models demonstrated that the microbial community assembly in HFCWs was primarily driven by stochastic processes under increasing influent CNR conditions. Furthermore, HFCWs with more stochastic microbial communities exhibited better denitrification performance (NO3--N removal). Overall, this study enhances our understanding of nutrient removal, microbial co-occurrence, and assembly mechanisms in CWs under varying influent CNRs.


Assuntos
Desnitrificação , Microbiota , Áreas Alagadas , Análise da Demanda Biológica de Oxigênio , Nitrificação , Nitrogênio/química , Água , Eliminação de Resíduos Líquidos/métodos
20.
Biomater Sci ; 12(7): 1761-1770, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38375617

RESUMO

The conundrum of wound healing has transformed into an imminent medical challenge. Presently, cell-free therapy centered around extracellular vesicles (EVs) has become a pivotal and promising research avenue. EVs generated from three-dimensional (3D) cell cultures have been previously established to possess enhanced tissue regeneration potential, although the underlying mechanisms remain elusive. In this study, we observed higher expression of annexin ANXA1 in 3D-cultured EVs. Remarkably, 3D-EVs with elevated ANXA1 expression demonstrated a more potent capacity to promote macrophage polarization from the M1 phenotype to the M2 phenotype. Concurrently, they exhibited superior abilities to enhance cell migration and tube formation, facilitating expedited wound healing in animal experiments. Conversely, the application of an ANXA1 inhibitor counteracted the positive effects of 3D-EVs. Taken together, our data validate that extracellular vesicles derived from 3D-cultured MSCs regulate macrophage polarization via ANXA1, thereby fostering wound healing.


Assuntos
Vesículas Extracelulares , Ativação de Macrófagos , Animais , Cicatrização , Vesículas Extracelulares/metabolismo , Técnicas de Cultura de Células , Movimento Celular
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