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1.
Bone ; 185: 117132, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38789096

RESUMEN

The mechanosensitivity of inflammation can alter cellular mechanotransduction. However, the underlying mechanism remains unclear. This study aims to investigate the metabolic mechanism of inflammation under mechanical force to guide tissue remodeling better. Herein, we found that inflammation hindered bone remodeling under mechanical force, accompanied by a simultaneous enhancement of oxidative phosphorylation (OXPHOS) and glycolysis. The control of metabolism direction through GNE-140 and Visomitin revealed that enhanced glycolysis might act as a compensatory mechanism to resist OXPHOS-induced osteoclastogenesis by promoting osteogenesis. The inhibited osteogenesis induced by inflammatory mechanical stimuli was concomitant with a reduced expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). PGC-1α knockdown impeded osteogenesis under mechanical force and facilitated osteoclastogenesis by enhancing OXPHOS. Conversely, PGC-1α overexpression attenuated the impairment of bone remodeling by inflammatory mechanical signals through promoting glycolysis. This process benefited from the PGC-1α regulation on the transcriptional and translational activity of lactate dehydrogenase A (LDHA) and the tight control of the extracellular acidic environment. Additionally, the increased binding between PGC-1α and LDHA proteins might contribute to the glycolysis promotion within the inflammatory mechanical environment. Notably, LDHA suppression effectively eliminated the bone repair effect mediated by PGC-1α overexpression within inflammatory mechanical environments. In conclusion, this study demonstrated a novel molecular mechanism illustrating how inflammation orchestrated glucose metabolism through glycolysis and OXPHOS to affect mechanically induced bone remodeling.

2.
J Orthop Surg Res ; 19(1): 257, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38649946

RESUMEN

BACKGROUND: The mechanotransduction mechanisms by which cells regulate tissue remodeling are not fully deciphered. Circular RNAs (circRNAs) are crucial to various physiological processes, including cell cycle, differentiation, and polarization. However, the effects of mechanical force on circRNAs and the role of circRNAs in the mechanobiology of differentiation and remodeling in stretched periodontal ligament stem cells (PDLSCs) remain unclear. This article aims to explore the osteogenic function of mechanically sensitive circular RNA protein kinase D3 (circPRKD3) and elucidate its underlying mechanotransduction mechanism. MATERIALS AND METHODS: PDLSCs were elongated with 8% stretch at 0.5 Hz for 24 h using the Flexcell® FX-6000™ Tension System. CircPRKD3 was knockdown or overexpressed with lentiviral constructs or plasmids. The downstream molecules of circPRKD3 were predicted by bioinformatics analysis. The osteogenic effect of related molecules was evaluated by quantitative real-time PCR (qRT-PCR) and western blot. RESULTS: Mechanical force enhanced the osteogenesis of PDLSCs and increased the expression of circPRKD3. Knockdown of circPRKD3 hindered PDLSCs from osteogenesis under mechanical force, while overexpression of circPRKD3 promoted the early osteogenesis process of PDLSCs. With bioinformatics analysis and multiple software predictions, we identified hsa-miR-6783-3p could act as the sponge of circPRKD3 to indirectly regulate osteogenic differentiation of mechanically stimulated PDLSCs. CONCLUSIONS: Our results first suggested that both circPRKD3 and hsa-miR-6783-3p could enhance osteogenesis of stretched PDLSCs. Furthermore, hsa-miR-6783-3p could sponge circPRKD3 to indirectly regulate RUNX2 during the periodontal tissue remodeling process in orthodontic treatment.


Asunto(s)
MicroARNs , Osteogénesis , Ligamento Periodontal , ARN Circular , Células Madre , Ligamento Periodontal/citología , Osteogénesis/genética , Osteogénesis/fisiología , Humanos , ARN Circular/genética , ARN Circular/fisiología , MicroARNs/genética , Células Madre/metabolismo , Células Cultivadas , Mecanotransducción Celular/fisiología , Diferenciación Celular/genética , Estrés Mecánico , Proteínas Serina-Treonina Quinasas/genética
3.
Angew Chem Int Ed Engl ; 63(15): e202319894, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38265268

RESUMEN

Membrane-based separation has the merit of low carbon footprint. In this study, the pore size of metal-organic framework (MOF) membranes is rationally designed for discriminating various pairs of hydrocarbon isomers. Specifically, Zr-MOF UiO-66 (UiO stands for University of Oslo) membranes are developed for separating p/o-xylene due to their proper pore size. For n-hexane/2-methylpentane separation, the functional groups and proportion of the ligands in UiO-66 are gradually adjusted to effectively regulate the pore size, and UiO-66-33Br membranes are constructed. In addition, relying on the utilization of ligands with shorter length, MOF-801 membranes with smaller pore size are fabricated for n/i-butane separation.

4.
Small ; 20(14): e2309360, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37990358

RESUMEN

Membrane-based separation process for unconventional natural gas purification (mainly N2/CH4 separation) has attracted more attention due to its considerable economic benefits. However, the majority of separation membranes at this stage, particularly N2-selective membranes, achieve the desired separation target by mainly relying on the diffusivity-selectivity mechanism. To overcome the limitation of a single mechanism, 2D lamellar MXene membranes with a double selectivity mechanism are prepared to enhance N2 permeance and N2/CH4 selectivity via introducing unsaturated metal sites into MXene, which can form specific interactions with N2 molecules and enhance N2 permeation. The resulting membranes exhibit an inspiring N2/CH4 separation performance with an N2 permeance of 344 GPU and N2/CH4 selectivity of 13.76. The collaboration of the double selectivity mechanism provides a new idea for the development of a novel N2-selective membrane for N2 removal and CH4 purification, which further broadens the application prospects of membrane separation technology in the field of unconventional natural gas purification.

5.
Small ; 20(22): e2308904, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38098304

RESUMEN

High-salinity wastewater treatment is perceived as a global water resource recycling challenge that must be addressed to achieve zero discharge. Monovalent/divalent salt separation using membrane technology provides a promising strategy for sulfate removal from chlor-alkali brine. However, existing desalination membranes often show low water permeance and insufficient ion selectivity. Herein, an aminal-linked covalent organic framework (COF) membrane featuring a regular long-range pore size of 7 Å and achieving superior ion selectivity is reported, in which a uniform COF layer with subnanosized channels is assembled by the chemical splicing of 1,4-phthalaldehyde (TPA)-piperazine (PZ) COF through an amidation reaction with trimesoyl chloride (TMC). The chemically spliced TPA-PZ (sTPA-PZ) membrane maintains an inherent pore structure and exhibits a water permeance of 13.1 L m-2 h-1 bar-1, a Na2SO4 rejection of 99.1%, and a Cl-/SO4 2- separation factor of 66 for mixed-salt separation, which outperforms all state-of-the-art COF-based membranes reported. Furthermore, the single-stage treatment of NaCl/Na2SO4 mixed-salt separation achieves a high NaCl purity of above 95% and a recovery rate of ≈60%, offering great potential for industrial application in monovalent/divalent salt separation and wastewater resource utilization. Therefore, the aminal-linked COF membrane developed in this work provides a new research avenue for designing smart/advanced membrane materials for angstrom-scale separations.

6.
ACS Appl Mater Interfaces ; 15(41): 48695-48704, 2023 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-37796665

RESUMEN

Positively charged nanofiltration (NF) membranes offer enormous potential for lithium-magnesium separation, hard water softening, and heavy metal removal. However, fundamental performance limitations for these applications exist in conventional polyamide-based NF membranes due to the negatively charged surface and low ion-ion selectivity. We hereby innovatively develop an advanced positively charged polyamine-based NF membrane built by the nucleophilic substitution of bromine and amine groups for precise ion-ion separation. Specifically, polyethylenimine (PEI) and 1,3,5-tris(bromomethyl)benzene (TBB) are interfacially polymerized to generate an amine-linked PEI-TBB selective layer with an ultrathin thickness of ∼95 nm, an effective pore size of 6.5 Å, and a strong positively charged surface with a zeta potential of +20.9 mV at pH 7. The PEI-TBB composite membrane achieves a water permeance of 4.2 L·m-2·h-1·bar-1, various divalent salt rejections above 90%, and separation factors above 15 for NaCl/MgCl2 and LiCl/MgCl2 mixed solutions. A three-stage NF process is implemented to achieve a Mg2+/Li+ mass ratio sharply decreasing from 50 to 0.11 with a total separation factor (SLi,Mg) of 455. Furthermore, the polyamine-based NF membrane exhibits excellent operational stability under continuous filtration and high operational pressure, demonstrating great application potential for precise ion-ion separation.

7.
ACS Appl Mater Interfaces ; 15(37): 43503-43514, 2023 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-37694956

RESUMEN

Rapid maxillary expansion (RME) is a common therapy for maxillary transverse deficiency. However, relapses after RME usually occur because of insufficient bone formation. MicroRNA-21 (miR-21) was reported as an important post-transcriptional modulator for osteogenesis. Herein, a photocontrolled miR-21 (PC-miR-21)-loaded nanosystem using upconversion nanoparticles (UCNPs) modified with poly(ether imide) (PEI), i.e., UCNPs@PEI@PC-miR-21, was constructed to promote bone formation in the midpalatal suture. UCNPs@PEI was constructed as the light transducer and delivery carrier. The UCNPs@PEI@PC-miR-21 nanocomplexes have good aqueous dispersibility and biocompatibility. The in vitro cell experiment suggested that UCNPs@PEI could protect PC-miR-21 from biodegradation and release PC-miR-21 into the cytoplasm under near-infrared light (NIR) irradiation. Furthermore, UCNPs@PEI@PC-miR-21 upregulated the expression of the osteogenic key markers, ALP, RUNX2, and COL1A1, at the levels of both genes and proteins. Besides, the results of the in vivo RME mice models further corroborated that photocontrollable UCNPs@PEI@PC-miR-21 accelerated bone formation with upregulating osteogenic markers of ALP, RUNX2, and osteoprotegerin and inducing fewer osteoclasts formation. In conclusion, UCNPs@PEI@PC-miR-21 nanoparticles with a NIR light could facilitate the remote and precise delivery of exogenous miR-21 to the midpalatal suture to promote bone formation during RME. This work represents a cutting-edge approach of gene therapy to promote osteogenesis in the midpalatal suture during RME and provides a frontier scientific basis for later clinical treatment.


Asunto(s)
MicroARNs , Nanopartículas , Animales , Ratones , Osteogénesis , Subunidad alfa 1 del Factor de Unión al Sitio Principal , Suturas , MicroARNs/genética
8.
BMC Med Inform Decis Mak ; 23(1): 186, 2023 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-37715187

RESUMEN

The Chinese government relaxed the Zero-COVID policy on Dec 15, 2022, and reopened the border on Jan 8, 2023. Therefore, COVID prevention in China is facing new challenges. Though there are plenty of prior studies on COVID, none is regarding the predictions on daily confirmed cases, and medical resources needs after China reopens its borders. To fill this gap, this study innovates a combination of the Erdos Renyl network, modified computational model [Formula: see text], and python code instead of only mathematical formulas or computer simulations in the previous studies. The research background in this study is Shanghai, a representative city in China. Therefore, the results in this study also demonstrate the situation in other regions of China. According to the population distribution and migration characteristics, we divided Shanghai into six epidemic research areas. We built a COVID spread model of the Erodos Renyl network. And then, we use python code to simulate COVID spread based on modified [Formula: see text] model. The results demonstrate that the second and third waves will occur in July-September and Oct-Dec, respectively. At the peak of the epidemic in 2023, the daily confirmed cases will be 340,000, and the cumulative death will be about 31,500. Moreover, 74,000 hospital beds and 3,700 Intensive Care Unit (ICU) beds will be occupied in Shanghai. Therefore, Shanghai faces a shortage of medical resources. In this simulation, daily confirmed cases predictions significantly rely on transmission, migration, and waning immunity rate. The study builds a mixed-effect model to verify further the three parameters' effect on the new confirmed cases. The results demonstrate that migration and waning immunity rates are two significant parameters in COVID spread and daily confirmed cases. This study offers theoretical evidence for the government to prevent COVID after China opened its borders.


Asunto(s)
COVID-19 , Epidemias , Cuarentena , SARS-CoV-2 , Humanos , Pueblo Asiatico , China/epidemiología , Simulación por Computador , COVID-19/epidemiología , COVID-19/prevención & control
9.
Cell Mol Biol Lett ; 28(1): 57, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37480044

RESUMEN

BACKGROUND: The preference for glucose oxidative mode has crucial impacts on various physiological activities, including determining stem cell fate. External mechanical factors can play a decisive role in regulating critical metabolic enzymes and pathways of stem cells. Periodontal ligament stem cells (PDLSCs) are momentous effector cells that transform mechanical force into biological signals during the reconstruction of alveolar bone. However, mechanical stimuli-induced alteration of oxidative characteristics in PDLSCs and the underlying mechanisms have not been fully elucidated. METHODS: Herein, we examined the expression of LDH and COX4 by qRT-PCR, western blot, immunohistochemistry and immunofluorescence. We detected metabolites of lactic acid and reactive oxygen species for functional tests. We used tetramethylrhodamine methyl ester (TMRM) staining and a transmission electron microscope to clarify the mitochondrial status. After using western blot and immunofluorescence to clarify the change of DRP1, we further examined MFF, PINK1, and PARKIN by western blot. We used cyclosporin A (CsA) to confirm the regulation of mitophagy and ceased the stretching as a rescue experiment. RESULTS: Herein, we ascertained that mechanical force could increase the level of LDH and decrease the expression of COX4 in PDLSCs. Simultaneously, the yield of reactive oxygen species (ROS) in PDLSC reduced after stretching, while lactate acid augmented significantly. Furthermore, mitochondrial function in PDLSCs was negatively affected by impaired mitochondrial membrane potential (MMP) under mechanical force, and the augment of mitochondrial fission further induced PRKN-dependent mitophagy, which was confirmed by the rescue experiments via blocking mitophagy. As a reversible physiological stimulation, the anaerobic preference of PDLSCs altered by mechanical force could restore after the cessation of force stimulation. CONCLUSIONS: Altogether, our study demonstrates that PDLSCs under mechanical force preferred anaerobic oxidation induced by the affected mitochondrial dynamics, especially mitophagy. Our findings support an association between mechanical stimulation and the oxidative profile of stem cells, which may shed light on the mechanical guidance of stem cell maintenance and commitment, and lay a molecular foundation for periodontal tissue regeneration.


Asunto(s)
Mitofagia , Ligamento Periodontal , Anaerobiosis , Especies Reactivas de Oxígeno , Oxidación-Reducción
10.
Polymers (Basel) ; 15(10)2023 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-37242904

RESUMEN

The orientation of amorphous regions in pure polymers has been noted to be critical to the enhancement of thermal conductivity (TC), but the available reports are still rather few. Here, we propose to prepare a polyvinylidene fluoride (PVDF) film with a multi-scale framework by introducing anisotropic amorphous nanophases in the form of cross-planar alignments among the in-planar oriented extended-chain crystals (ECCs) lamellae, which show an enhanced TC of 1.99 Wm-1 K-1 in the through-plane direction (K⟂) and 4.35 Wm-1 K-1 in the in-plane direction (K∥). Structural characterization determination using scanning electron microscopy and high-resolution synchrotron X-ray scattering showed that shrinking the dimension of the amorphous nanophases can effectively reduce entanglement and lead to alignments formation. Moreover, the thermal anisotropy of the amorphous region is quantitatively discussed with the aid of the two-phase model. Superior thermal dissipation performances are intuitively displayed by means of finite element numerical analysis and heat exchanger applications. Moreover, such unique multi-scale architecture also results in significant benefit in the improvement of dimensional stability and thermal stability. This paper provides a reasonable solution for fabricating inexpensive thermal conducting polymer films from the perspective of practical applications.

11.
Front Microbiol ; 14: 1110720, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37007521

RESUMEN

ST7 Staphylococcus aureus is highly prevalent in humans, pigs, as well as food in China; however, staphylococcal food poisoning (SFP) caused by this ST type has rarely been reported. On May 13, 2017, an SFP outbreak caused by ST7 S. aureus strains occurred in two campuses of a kindergarten in Hainan Province, China. We investigated the genomic characteristics and phylogenetic analysis of ST7 SFP strains combined with the 91 ST7 food-borne strains from 12 provinces in China by performing whole-genome sequencing (WGS). There was clear phylogenetic clustering of seven SFP isolates. Six antibiotic genes including blaZ, ANT (4')-Ib, tetK, lnuA, norA, and lmrS were present in all SFP strains and also showed a higher prevalence rate in 91 food-borne strains. A multiple resistance plasmid pDC53285 was present in SFP strain DC53285. Among 27 enterotoxin genes, only sea and selx were found in all SFP strains. A ФSa3int prophage containing type A immune evasion cluster (sea, scn, sak, and chp) was identified in SFP strain. In conclusion, we concluded that this SFP event was caused by the contamination of cakes with ST7 S. aureus. This study indicated the potential risk of new emergencing ST7 clone for SFP.

12.
J Clin Med ; 12(5)2023 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-36902577

RESUMEN

Microimplant-assisted rapid palatal expansion is increasingly used clinically; however, the effect on the upper airway volume in patients with maxillary transverse deficiency has not been thoroughly evaluated yet. The following electronic databases were searched up to August 2022: Medline via Ovid, Scopus, Embase, Web of Science, Cochrane Library, Google Scholar, and ProQuest. The reference lists of related articles were also reviewed by manual search. The Revised Cochrane Risk of Bias Tool for randomized trials (ROB2) and the Risk of Bias in non-randomized Studies of Interventions (ROBINS-I) tool were used to evaluate the risks of bias of the included studies. The mean differences (MD) and 95% confidence intervals (CI) of changes in nasal cavity and upper airway volume were analyzed using a random-effects model, and subgroup and sensitivity analyses were also performed. Two reviewers independently completed the process of screening studies, extracting data, and assessing the quality of studies. In total, twenty-one studies met the inclusion criteria. After assessing the full texts, only thirteen studies were included, with nine studies selected for quantitative synthesis. Oropharynx volume increased significantly after immediate expansion (WMD: 3156.84; 95% CI: 83.63, 6230.06); however, there was no significant change in nasal volume (WMD: 2527.23; 95% CI: -92.53, 5147.00) and nasopharynx volume (WMD: 1138.29; 95% CI: -52.04, 2328.61). After retention a period, significant increases were found in nasal volume (WMD: 3646.27; 95% CI: 1082.77, 6209.77) and nasopharynx volume (WMD: 1021.10; 95% CI: 597.11, 1445.08). However, there was no significant change after retention in oropharynx volume (WMD: 789.26; 95% CI: -171.25, 1749.76), palatopharynx volume (WMD: 795.13; 95% CI: -583.97, 2174.22), glossopharynx volume (WMD: 184.50; 95% CI: -1745.97, 2114.96), and hypopharynx volume (WMD: 39.85; 95% CI: -809.77, 889.46). MARPE appears to be linked with long-term increases in nasal and nasopharyngeal volume. However, high-quality clinical trials are required to further verify the effects of MARPE treatment on the upper airway.

13.
Environ Res ; 220: 115199, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36592808

RESUMEN

A heterotrophic nitrification-aerobic denitrification (HN-AD) strain isolated from membrane aerated biofilm reactor (MABR) was identified as Pseudomonas sp. B-1, which could effectively utilize multiple nitrogen sources and preferentially consume NH4-N. The maximum degradation efficiencies of NO3-N, NO2-N and NH4-N were 98.04%, 94.84% and 95.74%, respectively. The optimal incubation time, shaking speed, carbon source, pH, temperature and C/N ratio were 60 h, 180 rpm, sodium succinate, 8, 30 °C and 25, respectively. The strain preferred salinity of 1.5% and resisted heavy metals in the order of Mn2+ > Co2+ > Zn2+ > Cu2+. It can be preliminarily speculated from the results of enzyme assay that the strain removed nitrogen via full nitrification-denitrification pathway. The addition of strain into the conventional MABR significantly intensified the HN-AD performance of the reactor. The relative abundance of the functional bacteria including Flavobacterium, Pseudomonas, Paracoccus, Azoarcus and Thauera was obviously increased after the bioaugmentation. Besides, the expression of the HN-AD related genes in the biofilm was also strengthened. Thus, strain B-1 had great application potential in nitrogen removal process.


Asunto(s)
Desnitrificación , Nitrificación , Pseudomonas/genética , Pseudomonas/metabolismo , Aerobiosis , Nitrógeno/metabolismo , Biopelículas , Nitritos/metabolismo
14.
Cell Mol Biol Lett ; 28(1): 7, 2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36694134

RESUMEN

BACKGROUND: Mechanotransduction mechanisms whereby periodontal ligament stem cells (PDLSCs) translate mechanical stress into biochemical signals and thereby trigger osteogenic programs necessary for alveolar bone remodeling are being deciphered. Low-density lipoprotein receptor-related protein 6 (LRP6), a Wnt transmembrane receptor, has been qualified as a key monitor for mechanical cues. However, the role of LRP6 in the mechanotransduction of mechanically induced PDLSCs remains obscure. METHODS: The Tension System and tooth movement model were established to determine the expression profile of LRP6. The loss-of-function assay was used to investigate the role of LRP6 on force-regulated osteogenic commitment in PDLSCs. The ability of osteogenic differentiation and proliferation was estimated by alkaline phosphatase (ALP) staining, ALP activity assay, western blotting, quantitative real-time PCR (qRT-PCR), and immunofluorescence. Crystalline violet staining was used to visualize cell morphological change. Western blotting, qRT-PCR, and phalloidin staining were adopted to affirm filamentous actin (F-actin) alteration. YAP nucleoplasmic localization was assessed by immunofluorescence and western blotting. YAP transcriptional response was evaluated by qRT-PCR. Cytochalasin D was used to determine the effects of F-actin on osteogenic commitment and YAP switch behavior in mechanically induced PDLSCs. RESULTS: LRP6 was robustly activated in mechanically induced PDLSCs and PDL tissues. LRP6 deficiency impeded force-dependent osteogenic differentiation and proliferation in PDLSCs. Intriguingly, LRP6 loss caused cell morphological aberration, F-actin dynamics disruption, YAP nucleoplasmic relocation, and subsequent YAP inactivation. Moreover, disrupted F-actin dynamics inhibited osteogenic differentiation, proliferation, YAP nuclear translocation, and YAP activation in mechanically induced PDLSCs. CONCLUSIONS: We identified that LRP6 in PDLSCs acted as the mechanosensor regulating mechanical stress-inducible osteogenic commitment via the F-actin/YAP cascade. Targeting LRP6 for controlling alveolar bone remodeling may be a prospective therapy to attenuate relapse of orthodontic treatment.


Asunto(s)
Actinas , Proteína-6 Relacionada a Receptor de Lipoproteína de Baja Densidad , Osteogénesis , Ligamento Periodontal , Células Madre , Actinas/genética , Actinas/metabolismo , Diferenciación Celular/fisiología , Proliferación Celular , Células Cultivadas , Proteína-6 Relacionada a Receptor de Lipoproteína de Baja Densidad/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baja Densidad/metabolismo , Mecanotransducción Celular/genética , Mecanotransducción Celular/fisiología , Osteogénesis/genética , Osteogénesis/fisiología , Ligamento Periodontal/citología , Ligamento Periodontal/metabolismo , Células Madre/metabolismo
15.
Chemosphere ; 309(Pt 1): 136643, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36181858

RESUMEN

In order to reduce the resource and energy consumption of traditional biological nitrogen removal (BNR) process, heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria was in situ enriched in membrane aerated biofilm reactor (MABR) by inoculating conventional activated sludge. Contaminants removal performance, EPS composition and microbial community were explored. The results indicated that the average removal efficiency of COD and TN under optimal condition reached 84.13% and 91.54%, respectively, which demonstrated that the reactor possessed excellent contaminants removal capacity. EPS analysis suggested that abundant protein especially tryptophan protein-like substance played a vital role in maintaining the microbial stability of biofilms. Multiple HN-AD genera, mainly Paracoccus, were detected with the highest relative abundance of 54.70%, which confirmed the successful enrichment of the HN-AD bacteria. Conventional nitrifiers and denitrifiers also thrived in biofilm, which demonstrated the synergistic nitrogen removal of multiple microorganisms. This study provided important insights into application of HN-AD bacteria and synergistic nitrogen removal in BNR system.


Asunto(s)
Desnitrificación , Nitrificación , Procesos Heterotróficos , Aguas del Alcantarillado , Triptófano/metabolismo , Reactores Biológicos , Biopelículas , Nitrógeno/metabolismo , Bacterias/metabolismo , Aguas Residuales
16.
Nanoscale ; 14(26): 9341-9348, 2022 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-35704927

RESUMEN

An efficient and highly selective heterogeneous catalyst system for nitrile hydrogenation was developed using unsupported palladium nanopores (PdNPore). The PdNPore-catalyzed selective hydrogenation of nitriles proceeded smoothly, without any additives, under mild conditions (low H2 pressure and low temperature) to yield primary amines with satisfactory to excellent yields. Systematic studies demonstrated that the high activity and excellent selectivity of the PdNPore originated from its good Lewis acidity and porous structure. No palladium leached from the PdNPore during the hydrogenation reaction. Moreover, the catalyst was easily recovered and reused without any loss of catalytic activity. A deuterium-hydrogen exchange reaction clearly indicated that the present hydrogenation involves heterolytic H2 splitting on the surface of the PdNPore catalyst.

17.
ACS Appl Mater Interfaces ; 14(2): 2833-2847, 2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-34982527

RESUMEN

Two-dimensional (2D) layered transition-metal carbides (MXenes) are attractive faradic materials for an efficient capacitive deionization (CDI) process owing to their high capacitance, excellent conductivity, and remarkable ion storage capacity. However, the easy restacking property and spontaneous oxidation in solution by the dissolved oxygen of MXenes greatly restrict their further application in the CDI domain. Herein, a three-dimensional (3D) heterostructure (MoS2@MXene) is rationally designed and constructed, integrating the collective advantages of MXene flakes and MoS2 nanosheets through the hydrothermal method. In such a design, the well-dispersed MXene flakes can effectively reduce the aggregation of MoS2 nanosheets, boost electrical conductivity, and provide efficient charge transfer paths. Furthermore, MoS2 nanosheets as the high-capacity interlayer spacer can prevent the self-restacking of MXene flakes and provide more active sites for ion intercalation. Meanwhile, the strong chemical interactions between MXene flakes and MoS2 nanosheets contribute to accelerating the charge transfer kinetics and enhancing structural stability. Consequently, the resulting MoS2@MXene heterostructure electrode possesses high specific capacitance (171.4 F g-1), fast charge transfer and permeation rate, abundant Na+ diffusion channels, and superior electrochemical stability. Moreover, the hybrid CDI cell (AC//MoS2@MXene) with AC as the anode and MoS2@MXene as the cathode delivers outstanding desalination capacity (35.6 mg g-1), rapid desalination rate (2.6 mg g-1 min-1), excellent charge efficiency (90.2%), and good cyclic stability (96% retention rate). Most importantly, the MoS2@MXene electrode can keep good structural integrity after the long-term repeated desalination process due to the effective shielding effect of the MoS2 layer to protect MXenes from being further oxidized. This work presents the flexible structural engineering to realize excellent ion transfer and storage process by constructing the 3D heterostructure.

18.
J Am Chem Soc ; 143(48): 20055-20058, 2021 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-34812608

RESUMEN

New membrane materials with excellent water permeability and high ion rejection are needed. Metal-organic frameworks (MOFs) are promising candidates by virtue of their diversity in chemistry and topology. In this work, continuous aluminum MOF-303 membranes were prepared on α-Al2O3 substrates via an in situ hydrothermal synthesis method. The membranes exhibit satisfying rejection of divalent ions (e.g., 93.5% for MgCl2 and 96.0% for Na2SO4) on the basis of a size-sieving and electrostatic-repulsion mechanism and unprecedented permeability (3.0 L·m-2·h-1·bar-1·µm). The water permeability outperforms typical zirconium MOF, zeolite, and commercial polymeric reverse osmosis and nanofiltration membranes. Additionally, the membrane material exhibits good stability and low production costs. These merits recommend MOF-303 as a next-generation membrane material for water softening.

19.
Chemosphere ; 277: 130248, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33773315

RESUMEN

The high-efficiency solar evaporation is a potential technique to desalinate hypersaline wastewater and seawater to alleviate the global fresh water shortage. Photo-thermal agent and solar evaporator with low-cost raw materials, high photo-thermal conversion efficiency and simple-fast preparation methods is crucial to realize the industrial application of solar evaporation. Herein, carbon nanomaterial with higher light absorption and photo-thermal conversion efficiency than that of carbon black was obtained by combination treatment of carbon black with oxidation and flash illumination. In order to characterize the evaporation performance of the devices, a floating evaporator was fabricated with the carbon nanomaterial on the top of polyethylene foam wrapped with non-woven fabrics. The evaporation rate and photo-thermal conversion efficiency of evaporators were affected significantly by environmental temperature and humidity. At the environmental temperature of 19.5 °C, the evaporator fabricated with the combined treated carbon nanomaterial as photo-thermal agents presents a stable evaporation rate at 1.27 kg m-2 h-1 and solar evaporation efficiency at 78.7% under 1 kW m-2 simulated sun illumination, which are higher than those of evaporator with carbon black (1.13 kg m-2 h-1 and 68.1%). The distilled water obtained from the solar evaporator met the standards of drinkable water. Overall, the experimental result demonstrates a great promise application of treated carbon nanomaterial as a photo-thermal agent in the field of seawater desalination and solar-energy collector.


Asunto(s)
Nanoestructuras , Purificación del Agua , Carbono , Luz Solar , Agua
20.
Adv Mater ; 32(22): e1907701, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32329145

RESUMEN

Ultrathin unobstructed gas transport channels through the membrane selective layer are constructed in mixed matrix membranes (MMMs) by using gravity-induced interface self-assembly of poly(vinylamine) and polymer-modified MIL-101(Cr). For CO2 /N2 (15/85 by volume) mixed gas, the MMMs achieve a high CO2 permeance of 823 gas permeation units and CO2 /N2 selectivity of 242 at 0.5 MPa. Based on economic analyses, a two-stage membrane process can achieve gas separation and economic targets.

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