Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
RSC Adv ; 14(7): 4890-4903, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38323013

RESUMEN

A novel magnetic carbon-silicon composite (Fe-HH-CGFS) was prepared from solid waste coal gasification fine slag (CGFS) by a two-step acid leaching and one-step chemical co-precipitation process, which was optimized using a 3-factor, 3-level Box-Behnken design and then analyzed for correlation. Fe-HH-CGFS was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM) measurements. The results demonstrated that Fe-HH-CGFS had a reverse spinel structure with an average particle size of 5.14 nm, exhibiting a microporous/mesoporous structure with a specific surface area (SSA) of 196.84 m2 g-1 and pore volume of 0.346 cm3 g-1. Furthermore, Fe-HH-CGFS could achieve 97.59% removal efficiency of rhodamine B (RhB) under the optimal conditions: an initial concentration of RhB of 100 mg L-1, an adsorption time of 60 min, and a dosage of Fe-HH-CGFS of 1.0 g L-1. The pseudo-second-order model and the Langmuir isotherm satisfactorily described the adsorption behavior. The results indicated that the RhB removal process was a single-molecule layer endothermic adsorption, which is dominated by chemical adsorption reactions. This work is expected to provide an alternative route for the high-value utilization of CGFS and offer a valuable insight for the recycling of other solid wastes, aligning with the green development concept of "treating wastes with wastes".

2.
RSC Adv ; 14(4): 2705-2719, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38229713

RESUMEN

Coal gasification crude slag (CGCS) is the side-product of the coal gasification process, and its effective utilization has attracted great attention. A novel flocculant of poly-aluminum-ferric-acetate-chloride (PAFAC) was synthesized based on the recovery of CGCS by a two-step acid leaching process, namely HCl-acid leaching and HAc-acid leaching, which was optimized by an acid leaching liquor volume ratio of HCl to HAc of 3 : 2, polymerization pH of 3.5, and reaction temperature and time of 70 °C and 3.0 h, respectively. The performance of PAFAC was further evaluated by kaolin simulated wastewater, domestic sewage, river water, and aquaculture wastewater. The results revealed that PAFAC was feasible for the removal of turbidity, chemical oxygen demand (COD) and total phosphorus (TP). Moreover, PAFAC was characterized by X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray fluorescence spectrometry (XRF) and scanning electron microscopy (SEM), which proved that PAFAC was a kind of amorphous polyionic composite. Additionally, the acid leaching kinetics and flocculation mechanisms were further investigated. It was found that the acid leaching process was followed by the unreacted shrinkage core model, and the flocculation process was dominated by charge neutralization, adsorption bridging and precipitation net trapping. The work is expected to develop a new method for the safe disposal of CGCS and provide a novel way for the preparation of Fe-Al composite flocculants, especially, offering a potential strategy for the promotion of the additional value of the coal chemical industry.

3.
Nat Commun ; 14(1): 2179, 2023 04 17.
Artículo en Inglés | MEDLINE | ID: mdl-37069158

RESUMEN

A full understanding of the inactivated COVID-19 vaccine-mediated antibody responses to SARS-CoV-2 circulating variants will inform vaccine effectiveness and vaccination development strategies. Here, we offer insights into the inactivated vaccine-induced antibody responses after prime-boost vaccination at both the polyclonal and monoclonal levels. We characterized the VDJ sequence of 118 monoclonal antibodies (mAbs) and found that 20 neutralizing mAbs showed varied potency and breadth against a range of variants including XBB.1.5, BQ.1.1, and BN.1. Bispecific antibodies (bsAbs) based on nonoverlapping mAbs exhibited enhanced neutralizing potency and breadth against the most antibody-evasive strains, such as XBB.1.5, BQ.1.1, and BN.1. The passive transfer of mAbs or their bsAb effectively protected female hACE2 transgenic mice from challenge with an infectious Delta or Omicron BA.2 variant. The neutralization mechanisms of these antibodies were determined by structural characterization. Overall, a broad spectrum of potent and distinct neutralizing antibodies can be induced in individuals immunized with the SARS-CoV-2 inactivated vaccine BBIBP-CorV, suggesting the application potential of inactivated vaccines and these antibodies for preventing infection by SARS-CoV-2 circulating variants.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Femenino , Animales , Ratones , Humanos , SARS-CoV-2/genética , COVID-19/prevención & control , Anticuerpos Monoclonales , Anticuerpos Neutralizantes , Ratones Transgénicos , Vacunas de Productos Inactivados , Anticuerpos Antivirales
4.
IEEE Trans Neural Netw Learn Syst ; 34(11): 8310-8323, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35213315

RESUMEN

A variety of methods have been proposed for modeling and mining dynamic complex networks, in which the topological structure varies with time. As the most popular and successful network model, the stochastic block model (SBM) has been extended and applied to community detection, link prediction, anomaly detection, and evolution analysis of dynamic networks. However, all current models based on the SBM for modeling dynamic networks are designed at the community level, assuming that nodes in each community have the same dynamic behavior, which usually results in poor performance on temporal community detection and loses the modeling of node abnormal behavior. To solve the above-mentioned problem, this article proposes a hierarchical Bayesian dynamic SBM (HB-DSBM) for modeling the node-level and community-level dynamic behavior in a dynamic network synchronously. Based on the SBM, we introduce a hierarchical Dirichlet generative mechanism to associate the global community evolution with the microscopic transition behavior of nodes near-perfectly and generate the observed links across the dynamic networks. Meanwhile, an effective variational inference algorithm is developed and we can easy to infer the communities and dynamic behaviors of the nodes. Furthermore, with the two-level evolution behaviors, it can identify nodes or communities with abnormal behavior. Experiments on simulated and real-world networks demonstrate that HB-DSBM has achieved state-of-the-art performance on community detection and evolution. In addition, abnormal evolutionary behavior and events on dynamic networks can be effectively identified by our model.

5.
IEEE Trans Cybern ; 53(11): 7021-7033, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35507615

RESUMEN

Temporal community detection is helpful to discover and analyze significant groups or clusters hidden in dynamic networks in the real world. A variety of methods, such as modularity optimization, spectral method, and statistical network model, has been developed from diversified perspectives. Recently, network embedding-based technologies have made significant progress, and one can exploit deep learning superiority to network tasks. Although some methods for static networks have shown promising results in boosting community detection by integrating community embedding, they are not suitable for temporal networks and unable to capture their dynamics. Furthermore, the dynamic embedding methods only model network varying without considering community structures. Hence, in this article, we propose a novel unsupervised dynamic community detection model, which is based on network embedding and can effectively discover temporal communities and model dynamic networks. More specifically, we propose the community prior by introducing the Gaussian mixture model (GMM) in the variational autoencoder, which can obtain community information and better model the evolutionary characteristics of community structure and node embedding by utilizing the variant of gated recurrent unit (GRU). Extensive experiments conducted in real-world and artificial networks demonstrate that our proposed model has a better effect on improving the accuracy of dynamic community detection.

6.
Front Biosci (Landmark Ed) ; 28(12): 325, 2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-38179732

RESUMEN

BACKGROUND: The mortality rate of colorectal cancer (CRC) ranks second worldwide. Previous research had indicated that licochalcone A (LA) was a flavonoid in licorice with diverse anticancer effects. We explored the underlying mechanisms of LA-triggered anticancer activity in CRC. METHODS: Thiazolyl Blue (MTT) experiment and EdU staining were utilized to evaluate cell proliferation. Meanwhile, cells were stained by Annexin V/PI to investigate apoptosis through flow cytometry assay. Moreover, expressions of proteins were detected by immunoblotting, and the level of related mRNA was investigated using real-time quantitative PCR. RESULTS: LA selectively suppressed the proliferation and triggered apoptosis of CRC cells. Strikingly, LA induced cytoprotective autophagic activities since the suppression of autophagy significantly strengthened LA-induced cytotoxicity and FLICE inhibitory protein (c-FLIPL) degradation, meanwhile reversing LA-mediated heat shock protein 70 (Hsp70) upregulation. Moreover, autophagy-mediated Hsp70 upregulation resisted LA-induced anticancer effects since the suppression of Hsp70 strengthened LA-triggered cytotoxicity and c-FLIPL degradation. Furthermore, LA greatly activated extracellular signal-regulated protein kinases (ERK) and p38. However, blocking of ERK, but not p38, significantly boosted LA-triggered cell death and c-FLIPL downregulation. Suppression of ERK also reversed LA-mediated autophagic induction. CONCLUSIONS: LA increased Hsp70 expression depending on ERK-mediated autophagy, which protected CRC cells from LA-induced anticancer activities.


Asunto(s)
Proteínas HSP70 de Choque Térmico , Neoplasias , Humanos , Proteínas HSP70 de Choque Térmico/genética , Autofagia , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Proliferación Celular , Apoptosis , Línea Celular Tumoral
7.
Front Aging Neurosci ; 15: 1340706, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38288278

RESUMEN

Background: The calibrator in immunoassay plays an essential role in diagnosing Alzheimer's disease (AD). Presently, the most well-studied biomarkers for AD diagnosis are three phosphorylated Tau (p-Tau): p-Tau231, p-Tau217, and p-Tau181. Glycogen synthase-3beta (GSK3ß)-phosphorated Tau-441 is the most commonly used calibrator for p-Tau immunoassays. However, the batch-to-batch inconsistency issue of the commonly used GSK3ß-phosphorylated Tau-441 limits its clinical application. Methods: We have successfully generated and characterized 61 Tau monoclonal antibodies (mAbs) with distinct epitopes by using the hybridoma technique and employed them as capture or detection antibodies for p-Tau immunoassays. Through chemical synthesis, we synthesized calibrators, which are three peptides including capture and detection antibody epitopes, for application in immunoassays that detect p-Tau231, p-Tau217, and p-Tau181. The novel calibrators were applied to Enzyme-linked immunosorbent assay (ELISA) and Single-molecule array (Simoa) platforms to validate their applicability and establish a range of p-Tau immunoassays. Results: By employing the hybridoma technique, 49 mAbs recognizing Tau (1-22), nine mAbs targeting p-Tau231, one mAb targeting p-Tau217, and two mAbs targeting p-Tau181 were developed. Peptides, including recognition epitopes of capture and detection antibodies, were synthesized. These peptides were used as calibrators to develop 60 immunoassays on the ELISA platform, of which six highly sensitive immunoassays were selected and applied to the ultra-sensitive Simoa platform. Remarkably, the LODs were 2.5, 2.4, 31.1, 32.9, 46.9, and 52.1 pg/ml, respectively. Conclusion: Three novel p-Tau calibrators were successfully generated and validated, which solved the batch-to-batch inconsistency issue of GSK3ß-phosphorylated Tau-441. The novel calibrators exhibit the potential to promote the standardization of clinical AD diagnostic calibrators. Furthermore, we established a series of highly sensitive and specific immunoassays on the Simoa platform based on novel calibrators, which moved a steady step forward in p-Tau immunoassay application for AD diagnosis.

8.
J Mol Model ; 28(12): 388, 2022 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-36383257

RESUMEN

ReaxFF molecular dynamics (ReaxFF MD) simulations were performed to study the thermal decomposition property of cyclotrimethylenetrinitramine (RDX)-based composite modified double base (CMDB) propellants. The intermediate products and final products of the decomposition of RDX-based CMDB propellants at 2000 K, 2500 K, and 3000 K are obtained. The simulation results show that the decomposition of RDX and RDX/HTPB/Al is primary triggered by N-NO2 rupture, and then, the intermedia products undergo a series of complex interactions to form final products. The final products of RDX/HTPB/Al are H2 and N2, while the final products of pure RDX are H2, N2, and H2O. In addition, the abundance of the main intermediate products generated by RDX/HTPB/Al is lower than that of RDX, in that the reaction between intermediate products is more complex for RDX/HTPB/Al. Moreover, the decomposition rate of RDX/HTPB/Al increases with the increasing temperature.

9.
Artículo en Inglés | MEDLINE | ID: mdl-36232151

RESUMEN

Coal gasification fine slag (FS), a kind of by-product of coal chemical industry, was recovered for the preparation of functional adsorbents by acid leaching process, which was orthogonally optimized by HCl, HNO3, HF, HAc, and H2SO4. Methylene blue (MB) was used to evaluate the performance of functional adsorbents. The results demonstrated that 57.6% of the leaching efficiency (RLE) and 162.94 mg/g of adsorption capacity (CAC) of MB were achieved under the optimal conditions of HNO3 of 2.0 mol/L, acid leaching time of 2.0 h, and acid leaching temperature of 293K. The detections on X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and BET surface area (SBET) indicated that the synthesized functional adsorbents were characterized by mesoporous materials. The good fitting of adsorption process using pseudo-second-order and Langmuir models demonstrated that the chemisorption contributed to MB removal. The results of thermodynamics further revealed that the adsorption process of MB occurred spontaneously due to the exothermic properties. The work is expected to develop a novel and cost-effective strategy for the safe disposal of FS, and potentially offer an alternative pathway to increase the additional value for the coal chemical industry.

10.
Environ Toxicol ; 37(4): 814-824, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34989457

RESUMEN

Cadmium (Cd), a ubiquitous toxic heavy metal, with the intractable trait of low degradation, can induce multiple organ damage. Whereas, far less is known about its neurotoxicity and the specific mechanism in the chronic low Cd exposure. To investigate the chronic neurotoxicity of Cd2+ , we traced its effects for up to 30 months in mice which were exposed to Cd2+ by drinking the mimicking Cd-polluted water. We found the toxicity of chronic Cd exposure was a process associated with the transition from autophagy to apoptosis, and the switch of autophagy-apoptosis was Cd dose-dependent with the threshold of [Cd2+ ] 0.04 mg/L. Furthermore, JNK was found to be a hub molecule orchestrated the switch of autophagy-apoptosis by interacting with Sirt1 and p53. At last, the hippocampus-dependent learning and memory was damaged by continuous neuron apoptosis rather than deficit of neurogenesis. Therefore, elucidation of the effect, process, and potential molecular mechanism of the chronic low Cd2+ exposure is important for controlling of the environmental-pollutant Cd.


Asunto(s)
Cadmio , Neurogénesis , Animales , Apoptosis , Cadmio/metabolismo , Cadmio/toxicidad , Hipocampo/metabolismo , Trastornos de la Memoria/inducido químicamente , Ratones
11.
Bioresour Technol ; 343: 126141, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34655780

RESUMEN

In the present study, a dark fermentation system inoculated with mixed culture bacteria (MCB) was developed using prepared alkali-based magnetic nanosheets (AMNSs) to facilitate biohydrogen (BioH2) production. The highest BioH2 yields of 232.8 ± 8.5 and 150.3 ± 4.8 mL/g glucose were observed at 100 (mesophilic condition) and 400 (thermophilic condition) mg/L AMNSs groups, which were 65.4% and 43.3%, respectively, above the 0 mg/L AMNSs group. The fermentation pathway revealed that AMNSs enhanced the butyrate-type metabolic pathway and the corresponding nicotinamide adenine dinucleotides (NADHand NAD+) ratio, and hydrogenase activity was enhanced in mesophilic fermentation. The interaction of AMNSs and MCB suggested that AMNSs could assist in electron transfer and that the released metal elements might be responsible for elevated hydrogenase activity. AMNSs also promoted the evolution of the dominant microbial community and altered the content of extracellular polymers, leading to increased production of BioH2.


Asunto(s)
Hidrógeno , Microbiota , Álcalis , Fermentación , Fenómenos Magnéticos
12.
Micromachines (Basel) ; 12(11)2021 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-34832790

RESUMEN

This study was aimed at determining the effect of microstructure on the macro-mechanical behavior of a composite solid propellant. The microstructure model of a composite solid propellant was generated using molecular dynamics algorithm. The correlation of how microstructural mechanical properties and the effect of initial interface defects in propellant act on the macro-mechanics were studied. Results of this study showed that the mechanical properties of propellant rely heavily on its mesoscopic structure. The grain filling volume fraction mainly influences the propellant initial modulus, the higher the volume fraction, the higher initial modulus. Additionally, it was found that the ratio of particles influences the tensile strength and breaking elongation rate of the propellant. The big particles could also improve the initial modulus of a propellant, but decrease its tensile strength and breaking elongation rate. Furthermore, the initial defects lowered the uniaxial tensile modulus, tensile strength, and the relaxation modulus of propellant, but did not affect the relaxation behavior of the propellant.

13.
mBio ; 12(5): e0213021, 2021 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-34607455

RESUMEN

Gram-negative bacteria have a multicomponent and constitutively active periplasmic chaperone system to ensure the quality control of their outer membrane proteins (OMPs). Recently, OMPs have been identified as a new class of vulnerable targets for antibiotic development, and therefore a comprehensive understanding of OMP quality control network components will be critical for discovering antimicrobials. Here, we demonstrate that the periplasmic chaperone Spy protects certain OMPs against protein-unfolding stress and can functionally compensate for other periplasmic chaperones, namely Skp and FkpA, in the Escherichia coli K-12 MG1655 strain. After extensive in vivo genetic experiments for functional characterization of Spy, we use nuclear magnetic resonance and circular dichroism spectroscopy to elucidate the mechanism by which Spy binds and folds two different OMPs. Along with holding OMP substrates in a dynamic conformational ensemble, Spy binding enables OmpX to form a partially folded ß-strand secondary structure. The bound OMP experiences temperature-dependent conformational exchange within the chaperone, pointing to a multitude of local dynamics. Our findings thus deepen the understanding of functional compensation among periplasmic chaperones during OMP biogenesis and will promote the development of innovative antimicrobials against pathogenic Gram-negative bacteria. IMPORTANCE Outer membrane proteins (OMPs) play critical roles in bacterial pathogenicity and provide a new niche for antibiotic development. A comprehensive understanding of the OMP quality control network will strongly impact antimicrobial discovery. Here, we systematically demonstrate that the periplasmic chaperone Spy has a role in maintaining the homeostasis of certain OMPs. Remarkably, Spy utilizes a unique chaperone mechanism to bind OmpX and allows it to form a partially folded ß-strand secondary structure in a dynamic exchange of conformations. This mechanism differs from that of other E. coli periplasmic chaperones such as Skp and SurA, both of which maintain OMPs in disordered conformations. Our study thus deepens the understanding of the complex OMP quality control system and highlights the differences in the mechanisms of ATP-independent chaperones.


Asunto(s)
Proteínas de la Membrana Bacteriana Externa/química , Proteínas de la Membrana Bacteriana Externa/metabolismo , Membrana Celular/metabolismo , Escherichia coli K12/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Hidrolasas/química , Hidrolasas/metabolismo , Proteínas Periplasmáticas/metabolismo , Adenosina Trifosfato/metabolismo , Proteínas de la Membrana Bacteriana Externa/genética , Membrana Celular/química , Membrana Celular/genética , Escherichia coli K12/química , Escherichia coli K12/genética , Proteínas de Escherichia coli/genética , Hidrolasas/genética , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Isomerasa de Peptidilprolil/genética , Isomerasa de Peptidilprolil/metabolismo , Proteínas Periplasmáticas/genética , Unión Proteica , Conformación Proteica en Hélice alfa , Pliegue de Proteína
14.
Sci Total Environ ; 771: 144912, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33736162

RESUMEN

Nematodes generally occupy multiple trophic levels in detrital food webs, which play a vital role in energy flow, material conversion and nematodes community structure stability in the underground ecosystem. Sulfur (S) is one of the important soil nutrients, and it plays an important role in the nutrient cycle of grassland ecosystem. However, the impacts of S on soil fauna and subsurface detrital food webs in grassland ecosystems were rarely studied. Accordingly, to investigate the effects of sulfur deposition on soil nematodes and detrital food webs, we conducted a S addition experiment with distinct intensities from 0 to 50 g S m-2 yr-1 (S 0, S 1, S 2, S 5, S 10, S 15, S 20, and S 50) to simulated sulfur deposition in a meadow steppe of northern China. We documented a significant effect of S addition on the diversity and richness of nematodes, and the species richness of soil nematodes was high in the study site. But S addition had no significant effect on the total abundance and dominant species of nematodes (Cervidellus and Aphelenchus). Results of correlation analysis and structural equation modeling consistently indicated that omnivores-predators were significantly affected by sulfur addition. A significant increase in the Structural Index (which indicates food web structure) suggested increased top-down forces and changed community structure, although bacterivores, fungivores, plant parasites did not significantly. The present results suggest that sulfur deposition would change the composition of nematode community, affect the stability of nematode community structure, and increase the disturbance to the underground ecosystem. The study provides that the detailed information of the response of nematode to S deposition can be used to analyze the process of global change affecting the underground ecosystem.


Asunto(s)
Nematodos , Suelo , Animales , China , Ecosistema , Azufre
15.
ACS Omega ; 6(4): 2925-2933, 2021 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-33553911

RESUMEN

Fluorescent proteins (FPs) can be used as intrinsic molecular tags to track the dynamic activity in live cells. To obtain variants in an available and massive manner is always a challenge. Here, we adopted a computer-based microarray synthesis method to realize the reassembly between the chromophore and the skeleton. DNAWorks was used to segment the input FP templates into a set of overlapping oligonucleotides (20-43 mer) with a balanced annealing temperature, G + C content, and codon frequency. The constitution of the chromophore was kept in the same section by switching the divided sites during segmentation and the codon was optimized to further keep the balanced parameters. The designed oligonucleotides were synthesized on photo-programmable microfluidic arrays. Sequence analysis and the subsequent conditional induced expression of FPs revealed that oligonucleotides were highly reassembled. Spectra, photostability, and molecular size detection of randomly selected variants showed that they were distinct monomeric proteins that preserved photoactivity. Our study provides an effective means of obtaining FP variants based on a computer-designed parallel synthesis.

16.
Environ Technol ; 42(24): 3807-3819, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32167410

RESUMEN

The study aims to remove methylene blue dye from water with a fixed-bed column packed with Cu2O nanocomposite ceramsites. The column showed the advantages of fixed-bed column adsorption and photocatalytic oxidation. The Cu2O nanocomposite ceramsites with strong photocatalytic oxidation activity and well-developed porous structure were successfully prepared with the chemical vapour deposition process, which also met with the China's industrial standard of CJ/T 299-2008 and China's national standard of GB 5085.3-2007. In the column experiments under the experimental conditions (initial pH was 3, reaction temperature was 25°C and flow rate was 33 mL/min), the breakthrough curve was much more smooth. The breakthrough time and saturation time under ultraviolet radiation were 36.0% and 26.83% longer than those under the conditions without ultraviolet radiation, because the micro-pore structure of ceramsite was closely related to optical excitation properties of nano-Cu2O. The Yoon-Nelson and Adams-Bohart models were applied to describe the obtained breakthrough curves using non-linear regression, in which the Yoon-Nelson model gave the better prediction results for breakthrough curves, with R2>0.98. Besides, amines were the dominant intermediates at saturation point and final products were inorganic anions. This study confirmed that the fixed-bed column packed with Cu2O nanocomposite ceramsites could efficiently treat methylene blue dye wastewater, due to the structure-function relationship between ceramsite and nano-Cu2O.


Asunto(s)
Nanocompuestos , Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Mezclas Complejas , Azul de Metileno , Rayos Ultravioleta , Agua
17.
Protein Sci ; 29(9): 1964-1974, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32715541

RESUMEN

Quantum yield is a determinant for fluorescent protein (FP) applications and enhancing FP brightness through gene engineering is still a challenge. Green2, our de novo FP synthesized by microfluidic picoarray and cloning, has a significantly lower quantum yield than enhanced green FP, though they have high homology and share the same chromophore. To increase its quantum yield, we introduced an F145Y substitution into Green2 based on rational structural analysis. Y145 significantly increased the quantum yield (0.22 vs. 0.18) and improved the photostability (t1/2 , 73.0 s vs. 46.0 s), but did not affect the excitation and emission spectra. Further structural analysis showed that the F145Y substitution resulted in a significant electrical field change in the immediate environment of the chromophore. The perturbation of electrostatic charge around the chromophore lead to energy barrier changes between the ground and excited states, which resulted in the enhancement of quantum yield and photostability. Our results illustrate a typical example of engineering an FP based solely on fluorescence efficiency optimization and provide novel insights into the rational evolution of FPs.


Asunto(s)
Sustitución de Aminoácidos , Proteínas Fluorescentes Verdes/química , Modelos Moleculares , Mutación Missense , Proteínas Fluorescentes Verdes/genética , Estabilidad Proteica
18.
J Biol Chem ; 295(38): 13287-13298, 2020 09 18.
Artículo en Inglés | MEDLINE | ID: mdl-32723864

RESUMEN

The spindle apparatus segregates bi-oriented sister chromatids during mitosis but mono-oriented homologous chromosomes during meiosis I. It has remained unclear if similar molecular mechanisms operate to regulate spindle dynamics during mitosis and meiosis I. Here, we employed live-cell microscopy to compare the spindle dynamics of mitosis and meiosis I in fission yeast cells and demonstrated that the conserved kinesin-14 motor Klp2 plays a specific role in maintaining metaphase spindle length during meiosis I but not during mitosis. Moreover, the maintenance of metaphase spindle stability during meiosis I requires the synergism between Klp2 and the conserved microtubule cross-linker Ase1, as the absence of both proteins causes exacerbated defects in metaphase spindle stability. The synergism is not necessary for regulating mitotic spindle dynamics. Hence, our work reveals a new molecular mechanism underlying meiotic spindle dynamics and provides insights into understanding differential regulation of meiotic and mitotic events.


Asunto(s)
Metafase , Proteínas Asociadas a Microtúbulos/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Huso Acromático/metabolismo , Proteínas Asociadas a Microtúbulos/genética , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/genética , Huso Acromático/genética
19.
Ying Yong Sheng Tai Xue Bao ; 31(5): 1579-1586, 2020 May.
Artículo en Chino | MEDLINE | ID: mdl-32530236

RESUMEN

Increasing nitrogen (N) deposition results in soil acidification in grasslands. Acid buffering capacity of soil is a critical index evaluating soil acidification, the response of which to N input is regulated by precipitation and concentration of other limiting elements. To explore the responses of soil acidification to N, phosphorus (P), and water inputs, we conducted a 13-year field experiment in an old-field grassland and calculated the acid buffering capacity (ABC) and acid neutralizing capacity (ANC) at the reference of pH=5.0 (ANCpH5.0) and 4.0 (ANCpH4.0), using quadratic curve fitting model. The results showed that, without water addition, single N addition or combined with P addition significantly decreased soil pH, ANCpH5.0 and ANCpH4.0, whereas single P addition had no significant effect on soil pH, ANCpH5.0 or ANCpH4.0. With water addition, the addition of N or combined with P decreased soil pH, ANCpH5.0 and ANCpH4.0, whereas P addition decreased soil pH, increased ANCpH4.0, without effect on ANCpH5.0. In contrast with treatments without water addition, water addition had positive effects on soil pH, ANCpH5.0 and ANCpH4.0. For soils with different initial soil pH values, it was better to select ANC rather than ABC as an index to evaluate soil anti-acidification capacity.


Asunto(s)
Pradera , Suelo , Nitrógeno , Fósforo , Agua
20.
Biotechnol Lett ; 42(4): 681, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32016809

RESUMEN

In the original publication of the article, under the "Acknowledgement" section, the Grant No. 31611011097 should read as No. 31661143021.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...