Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.500
Filtrar
1.
Food Funct ; 12(20): 9866-9879, 2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34664604

RESUMO

Oyster is a common food that causes allergy. However, little information is available about its allergens and cross-reactivity. In this study, arginine kinase (AK) was identified as a novel allergen in Crassostrea angulata. The primary sequence of AK was cloned which encoded 350 amino acids, and recombinant AK (rAK) was obtained. The immunodot results, secondary structure and digestive stability showed that native AK and rAK had similar IgG/IgE-binding activity and physicochemical properties. Serological analysis of 14 oyster-sensitive individuals demonstrated that AK exhibited cross-reactivity among oysters, shrimps, and crabs. Furthermore, nine epitopes in oyster AK were verified using inhibition dot blots and inhibition enzyme linked immunosorbent assay, six of which were similar to the epitopes of shrimp/crab AK. The most conserved epitopes were P5 (121-133) and P6 (133-146), which may be responsible for the cross-reactivity caused by AK. These findings will provide a deeper understanding of oyster allergens and cross-reactivity among shellfish.

2.
Opt Lett ; 46(19): 4848-4851, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34598215

RESUMO

The bidirectional ultrafast fiber laser is a promising light source for dual-comb applications. The counter-propagating geometry could lead to soliton interaction through gain sharing, as well as the possible outcome of polarization instability. However, the polarization dynamics hidden behind the soliton interaction process in bidirectional fiber lasers were rarely investigated. Herein, we report on the polarization instability induced by the mutual soliton interactions through fiber gain in a bidirectional mode-locked fiber laser. Depending on the adjustment of the intracavity birefringence, the polarization states of two counter-propagating solitons can exhibit similar periodical polarization switching behaviors with a polarization-rotating transition state. The successive interactions of the bidirectional solitons mediated by the polarization cross-saturation effect of gain fiber could be responsible for the soliton polarization instability. These findings, in addition to the fundamental interest of the soliton nonlinear dynamics in dissipative optical systems, also open up new possibilities for creating dynamical control of the soliton polarization state and performance improvement in bidirectional ultrafast fiber lasers.

3.
Chem Commun (Camb) ; 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34651618

RESUMO

Detection and characterization of DNA damage plays a critical role in genotoxicity testing, drug screening, and environmental health. We developed a fully integrated origami paper-based analytical device (oPAD) for measuring DNA damage. This simple device allows on-paper cell lysis, DNA extraction, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) reaction and signal readout with simple operation steps, enabling rapid (within 30 min) and high throughput assessment of multiple DNA damages induced by exogenous chemical agents.

4.
Nano Lett ; 2021 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-34605657

RESUMO

The van der Waals (vdW) heterostructures have rich functions and intriguing physical properties, which has attracted wide attention. Effective control of excitons in vdW heterostructures is still urgent for fundamental research and realistic applications. Here, we successfully achieved quantitative tuning of the intralayer exciton of monolayers and observed the transition from intralayer excitons to interlayer excitons in WS2/MoSe2 heterostructures, via hydrostatic pressure. The energy of interlayer excitons is in a "locked" or "superstable" state, which is not sensitive to pressure. The first-principles calculation reveals the stronger interlayer interaction which leads to enhanced interlayer exciton behavior in WS2/MoSe2 heterostructures under external pressure and reveals the robust peak of interlayer excitons. This work provides an effective strategy to study the interlayer interaction in vdW heterostructures and reveals the enhanced interlayer excitons in WS2/MoSe2, which could be of great importance for the material and device design in various similar quantum systems.

5.
Artigo em Inglês | MEDLINE | ID: mdl-34612635

RESUMO

In this work, a novel multilayer solid electrolyte interphase (SEI) is demonstrated to prolong the durability of a lithium-metal anode. It is in situ generated via reducing lithium bis(oxalate) borate (LiBOB) and fluoroethylene carbonate (FEC) in the electrolyte containing them as additives. The as-obtained SEI could be roughly divided into three layers: the polycarbonates surface membrane, LiF-rich middle layer, and B-containing polymer bottom film corresponding to their sequentially reductive potentials of 0.8, 1.55, and 1.8 V vs Li+/Li, respectively. This special structure prolongs the durability of lithium-metal anode since the elastic bottom layer could buffer the influence of volumetric variation and the LiF-rich middle layer could suppress Li dendrite growth and electrolyte permeation. Benefiting from the protection of this multilayer SEI, LiNi0.88Co0.09Al0.03O2/Li batteries with ultrahigh cathode loading of ∼4.5 mAh cm-2 stably operate for 200 cycles with the accumulated capacity of 750 mAh cm-2 and the coulombic efficiency of 99.78%. This approach provides a simple and efficient strategy to hover lithium-metal anode.

6.
Virus Res ; : 198593, 2021 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-34637814

RESUMO

Zika virus (ZIKV) is a typical mosquito-borne flavivirus known to cause severe fetal microcephaly and adult Guillain-Barré syndrome. Currently, there are no specific drugs or licensed vaccines available for ZIKV infection, and further research is required to identify host cell proteins involved in the virus's life cycle. Viruses are known to use host cell membrane skeletal proteins, such as actin and spectrin, to complete cell entry, transportation, and release. Here, based on immunoprecipitation, the Axl and ZIKV envelope (E) protein were shown to interact with the cell membrane skeleton protein 4.1R. Furthermore, deletion of 4.1R significantly reduced virus titer and viral protein synthesis. Our study showed that 4.1R is an important host cell protein during ZIKV infection and may be involved in the process of viral entry into host cells.

7.
Front Public Health ; 9: 575315, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34595146

RESUMO

Objective: The aim of this study is to analyze the latent class of basic reproduction number (R 0) trends of the 2019 novel coronavirus disease (COVID-19) in the major endemic areas of China. Methods: The provinces that reported more than 500 cases of COVID-19 till February 18, 2020 were selected as the major endemic areas. The Verhulst model was used to fit the growth rate of cumulative confirmed cases. The R 0 of COVID-19 was calculated using the parameters of severe acute respiratory syndrome (SARS) and COVID-19. The latent class of R 0 was analyzed using the latent profile analysis (LPA) model. Results: The median R 0 calculated from the SARS and COVID-19 parameters were 1.84-3.18 and 1.74-2.91, respectively. The R 0 calculated from the SARS parameters was greater than that calculated from the COVID-19 parameters (Z = -4.782 to -4.623, p < 0.01). Both R 0 can be divided into three latent classes. The initial value of R 0 in class 1 (Shandong Province, Sichuan Province, and Chongqing Municipality) was relatively low and decreased slowly. The initial value of R 0 in class 2 (Anhui Province, Hunan Province, Jiangxi Province, Henan Province, Zhejiang Province, Guangdong Province, and Jiangsu Province) was relatively high and decreased rapidly. Moreover, the initial R 0 value of class 3 (Hubei Province) was in the range between that of classes 1 and 2, but the higher R 0 level lasted longer and decreased slowly. Conclusion: The results indicated that the overall R 0 trend is decreased with the strengthening of comprehensive prevention and control measures of China for COVID-19, however, there are regional differences.


Assuntos
COVID-19 , SARS-CoV-2 , Número Básico de Reprodução , China/epidemiologia , Humanos , Incidência
8.
NPJ Precis Oncol ; 5(1): 81, 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34508169

RESUMO

Kinase fusions represent an important type of somatic alterations that promote oncogenesis and serve as diagnostic markers in lung cancer. We aimed to identify the landscape of clinically relevant kinase fusions in Chinese lung cancer and to explore rare kinase rearrangements; thus, providing valuable evidence for therapeutic decision making. We performed genomic profiling of 425 cancer-relevant genes from tumor/plasma biopsies from a total of 17,442 Chinese lung cancer patients using next generation sequencing (NGS). Patients' clinical characteristics and treatment histories were retrospectively studied. A total of 1162 patients (6.66%; 1162/17,442) were identified as having kinase fusions, including 906 adenocarcinomas (ADCs) and 35 squamous cell carcinomas (SCCs). In ADC, 170 unique gene fusion pairs were observed, including rare kinase fusions, SLC12A2-ROS1, NCOA4-RET, and ANK3-RET. As for SCC, 15 unique gene fusions were identified, among which the most frequent were EML4-ALK and FGFR3-TACC3. Analyses of oncogenic mutations revealed a dual role for the gene fusions, CCDC6-RET and FGFR3-TACC3, in driving oncogenesis or serving as acquired resistance mechanisms to kinase inhibitors. In addition, our real-world evidence showed that patients with recurrent kinase fusions with low frequency (two occurrences) could benefit from treatment with kinase inhibitors' off-label use. Notably, patients with stage IV ADC who had novel RORB-ALK or AFF2-RET fusions, but no other known oncogenic driver mutations, demonstrated favorable clinical outcomes on tyrosine kinase inhibitors. Our data provide a comprehensive overview of the landscape of oncogenic kinase fusions in lung cancer, which assist in recognizing potentially druggable fusions that can be translated into therapeutic applications.

9.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 43(4): 579-583, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34494529

RESUMO

Objective To evaluate lateral pterygoid muscle(LPM)contraction in the patients with temporomandibular disorders(TMD)based on 3D-T2 weighted imaging(3D-T2WI).Multiplanar reconstruction(MPR)was employed to measure the length of LPM in the images taken in closed-and open-mouth positions. Methods Seventeen TMD patients [age of(29.82±10.70)years,males/females=8/9] and 13 normal volunteers [control,age of(23.54±3.31)years,males/females=6/7] received 3D-T2WI of the temporomandibular joints in closed-and open-mouth positions from November 2019 to April 2020 in Department of Radiology,Hainan Hospital of Chinese PLA General Hospital.According to the position of the discs,the subjects were classified into the following groups:TMD with disc displacement without reduction(TMD-DDwoR),TMD with disc displacement with reduction(TMD-DDwR),TMD without disc displacement(TMDwoDD),and normal control without disc displacement(NCwoDD).MPR was employed to measure the maximal length of the superior belly of LPM.One-way analysis of variance,receiver operating characteristic curve,and permutation test were employed for the statistical analyses. Results The contraction of LPM was significantly shorter in TMD-DDwoR group [(3.36±1.96)mm] than in TMDwoDD group [(7.90±3.95)mm],NCwoDD group [(8.77±3.13)mm](F=12.891,P=0.000),and TMD-DDwR group[(7.12±3.69)mm](χ2=5.314,P=0.031). Conclusion This study confirmed that the contraction of LPM decreased in patients with TMD-DDwoR,which provided imaging evidence for the study of disc displacement mechanism in TMD patients.


Assuntos
Luxações Articulares , Transtornos da Articulação Temporomandibular , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Contração Muscular , Músculos Pterigoides/diagnóstico por imagem , Disco da Articulação Temporomandibular , Transtornos da Articulação Temporomandibular/diagnóstico por imagem , Adulto Jovem
10.
Curr Med Chem ; 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34514982

RESUMO

Protein-ligand interactions are necessary for majority protein functions. Adenosine-5'-triphosphate (ATP) is one such ligand that plays vital role as a coenzyme in providing energy for cellular activities, catalyzing biological reaction and signaling. Knowing ATP binding residues of proteins is helpful for annotation of protein function and drug design. However, due to the huge amounts of protein sequences influx into databases in the post-genome era, experimentally identifying ATP binding residues is cost-ineffective and time-consuming. To address this problem, computational methods have been developed to predict ATP binding residues. In this review, we briefly summarized the application of machine learning methods in detecting ATP binding residues of proteins. We expect this review will be helpful for further research.

12.
Environ Microbiol ; 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34472190

RESUMO

Magnaporthe oryzae is an important plant pathogen that causes rice blast. Hse1 and Vps27 are components of ESCRT-0 involved in the multivesicular body (MVB) sorting pathway and biogenesis. To date, the biological functions of ESCRT-0 in M. oryzae have not been determined. In this study, we identified and characterized Hse1 and Vps27 in M. oryzae. Disruption of MoHse1 and MoVps27 caused pleiotropic defects in growth, conidiation, sexual development and pathogenicity, thereby resulting in loss of virulence in rice and barley leaves. Disruption of MoHse1 and MoVps27 triggered increased lipidation of MoAtg8 and degradation of GFP-MoAtg8, indicating that ESCRT-0 is involved in the regulation of autophagy. ESCRT-0 was determined to interact with coat protein complex II (COPII), a regulator functioning in homeostasis of the endoplasmic reticulum (ER homeostasis), and disruption of MoHse1 and MoVps27 also blocked activation of the unfolded protein response (UPR) and autophagy of the endoplasmic reticulum (ER-phagy). Overall, our results indicate that ESCRT-0 plays critical roles in regulating fungal development, virulence, autophagy and ER-phagy in M. oryzae.

13.
J Med Biol Eng ; : 1-10, 2021 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-34512223

RESUMO

Purpose: Sleep is an important human activity. Comfortable sensing and accurate analysis in sleep monitoring is beneficial to many healthcare and medical applications. From 2020, owing to the COVID­19 pandemic that spreads between people when they come into close physical contact with one another, the willingness to go to hospital for receiving care has reduced; care-at-home is the trend in modern healthcare. Therefore, a home-use and real-time sleep-staging system is developed in this paper. Methods: We developed and implemented a real-time sleep staging system that integrates a wearable eye mask for high-quality electroencephalogram/electrooculogram measurement and a mobile device with MobileNETV2 deep learning model for sleep-stage identification. In the experiments, 25 all-night recordings were acquired, 17 of which were used for training, and the remaining eight were used for testing. Results: The averaged scoring agreements for the wake, light sleep, deep sleep, and rapid eye movement stages were 85.20%, 87.17%, 82.87%, and 89.30%, respectively, for our system compared with the manual scoring of PSG recordings. In addition, the mean absolute errors of four objective sleep measurements, including sleep efficiency, total sleep time, sleep onset time, and wake after sleep onset time were 1.68%, 7.56 min, 5.50 min, and 3.94 min, respectively. No significant differences were observed between the proposed system and manual PSG scoring in terms of the percentage of each stage and the objective sleep measurements. Conclusion: These experimental results demonstrate that our system provides high scoring agreements in sleep staging and unbiased sleep measurements owing to the use of EEG and EOG signals and powerful mobile computing based on deep learning networks. These results also suggest that our system is applicable for home-use real-time sleep monitoring.

14.
Mol Pharm ; 18(10): 3750-3762, 2021 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-34491767

RESUMO

Arg-Arg-Leu (RRL) is a potent tumor-homing tripeptide. However, the binding target is unclear. In this study, we intended to identify the binding target of RRL and evaluate the tumor targeting of 99mTc-MAG3-RRL in vivo. Biotin-RRL, 5-TAMRA-RRL, and 99mTc-MAG3-RRL were designed to trace the binding target and tumor lesion. Immunoprecipitation-mass spectrometry was conducted to identify the candidate proteins and determination of the subcellular localization was also performed. A pull-down assay was performed to demonstrate the immunoprecipitate. Fluorescence colocalization and cell uptake assays were performed to elucidate the correlation between the selected binding protein and RRL, and the internalization mechanism of RRL. Biodistribution and in vivo imaging were performed to evaluate the tumor accumulation and targeting of 99mTc-MAG3-RRL. The target for RRL was screened to be heat shock protein 70 (HSP70). The prominent uptake distribution of RRL was concentrated in the membrane and cytoplasm. A pull-down assay demonstrated the existence of HSP70 in the biotin-RRL captured complex. Regarding fluorescence colocalization and cell uptake assays, RRL may interact with HSP70 at the nucleotide-binding domain (NBD). Clathrin-dependent endocytosis and macropinocytosis could be a vital internalization mechanism of RRL. In vivo imaging and biodistribution both demonstrated that 99mTc-MAG3-RRL can trace tumors with satisfactory accumulation in hepatoma xenograft mice. The radioactive signals accumulated in tumor lesions can be blocked by VER-155008, which can bind to the NBD of HSP70. Our findings revealed that RRL may interact with HSP70 and that 99mTc-MAG3-RRL could be a prospective probe for visualizing overexpressed HSP70 tumor sections.

15.
Food Chem ; 371: 131132, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34555704

RESUMO

Filamin C (FLN c) and triosephosphate isomerase (TIM) are novel allergens of crab (Scylla paramamosain) which are sharing common epitopes. This work aimed to assess their contributions to the induction and elicitation of allergenic responses. Balb/c mice were sensitized by intraperitoneal injections and challenged by intragastric gavage with purified proteins. Upon oral challenge, FLN c triggered more severe anaphylactic symptoms, higher levels of specific antibodies and histamine in serum than TIM, while TIM was a more active promotor of early specific antibody production and stimulated stronger Th2-biased responses. Combined with the results of in vitro assays, the data demonstrated that though with common epitopes, the two allergens showed a different allergenicity, TIM favored Th2 polarization in sensitization stage, while FLN c had a better ability to stimulate B cells and is highly immunogenic in oral challenge stage. The findings can help with the better understanding of allergenicity of crab allergens.

16.
J Clin Invest ; 131(20)2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34473650

RESUMO

Atrial natriuretic peptide (ANP) is an important hormone in cardiovascular biology. It is activated by the protease corin. In pregnancy, ANP and corin promote uterine spiral artery remodeling, but the underlying mechanism remains unknown. Here we report an ANP function in uterine decidualization and TNF-related apoptosis-inducing ligand-dependent (TRAIL-dependent) death in spiral arterial smooth muscle cells (SMCs) and endothelial cells (ECs). In ANP- or corin-deficient mice, uterine decidualization markers and TRAIL expression were decreased, whereas in cultured human endometrial stromal cells (HESCs), ANP increased decidualization and TRAIL expression. In uterine spiral arteries from pregnant wild-type mice, SMC and EC loss occurred sequentially before trophoblast invasion. In culture, TRAIL from decidualized HESCs induced apoptosis in uterine SMCs, but not in ECs with low TRAIL receptor expression. Subsequently, cyclophilin B was identified from apoptotic SMCs that upregulated endothelial TRAIL receptor and caused apoptosis in ECs. These results indicate that ANP promotes decidualization and TRAIL expression in endometrial stromal cells, contributing to sequential events in remodeling of spiral arteries, including SMC death and cyclophilin B release, which in turn induces TRAIL receptor expression and apoptosis in ECs.

17.
Acc Chem Res ; 54(18): 3540-3549, 2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34478272

RESUMO

Pathogens have long presented a significant threat to human lives, and hence the rapid detection of infectious pathogens is vital for improving human health. Current detection methods lack the means to detect infectious pathogens in a simple, rapid, and reliable manner at the time and point of need. Functional nucleic acids (FNAs) have the potential to overcome these limitations by acting as key components for point-of-care (POC) biosensors due to their distinctive advantages that include high binding affinities and specificities, excellent chemical stability, ease of synthesis and modification, and compatibility with a variety of signal-amplification and signal-transduction mechanisms.This Account summarizes the work completed in our groups toward developing FNA-based biosensors for detecting bacteria. In vitro selection has led to the isolation of many RNA-cleaving fluorogenic DNAzymes (RFDs) and DNA aptamers that can recognize infectious pathogens, including Escherichia coli, Clostridium difficile, Helicobacter pylori, and Legionella pneumophila. In most cases, a "many-against-many" approach was employed using a DNA library against a crude cellular mixture of an infectious pathogen containing diverse biomarkers as the target to isolate RFDs, with combined counter and positive selections ensuring high specificity toward the desired target. This procedure allows for the isolation of pathogen-specific FNAs without first identifying a suitable biomarker. Multiple target-specific DNA aptamers, including anti-glutamate dehydrogenase (GDH) circular aptamers, anti-degraded toxin B aptamers, and anti-RNase HII aptamers, have also been isolated for the detection of bacteria such as Clostridium difficile. The isolated FNAs have been integrated into fluorescent, colorimetric, and electrochemical biosensors using various signal transduction mechanisms. Both simple-to-use paper-based analytical devices and hand-held electrical devices with integrated FNAs have been developed for POC applications. In addition, signal-amplification strategies, including DNA catenane enabled rolling circle amplification (RCA), DNAzyme feedback RCA, and an all-DNA amplification system using a four-way junction and catalytic hairpin assembly (CHA), have been designed and applied to these systems to further increase their detection sensitivity. The use of these FNA-based biosensors to detect pathogens directly in clinical samples, such as urine, blood, and stool, has now been demonstrated with an outstanding sensitivity of as low as 10 cells per milliliter, highlighting the tremendous potential of using FNA-based sensors in clinical applications. We further describe strategies to overcome the challenges of using FNA-based biosensors in clinical applications, including strategies to improve the stability of FNAs in biological samples and prevent their nonspecific degradation from nucleases and strategies to deal with issues such as signal loss caused by nonspecific binding and biofouling. Finally, the remaining roadblocks for employing FNA-based biosensors in clinical applications are discussed.

18.
J Environ Manage ; 299: 113641, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34479150

RESUMO

Aerobic denitrifying bacteria have the potential to remove the co-pollutants Ni(II) and nitrate in industrial wastewater. In this study, aerobic denitrifying bacteria with significant Ni(II) removal efficiency was isolated from the biological reaction tank and named as Pseudomonas hibiscicola L1 strain after 16 S rRNA identification analysis. The removal of ever-increasing Ni(II) and NO3--N wastewater under aerobic conditions by strain L1 was discussed. The experimental results showed that strain L1 removed 84% of Ni(II) and 81% of COD, with the use of 34.8 mg L-1 of nitrogen source and without nitrite accumulation yet. Strain L1 had remarkable activity (OD600 = 0.51-0.56 (p < 0.05)) at 20 mg L-1 of Ni(II) and 100 mg L-1 of NO3--N. It was found that high Ni(II) gradients (2-10 mg L-1) had little effect on nitrate removal ratio (35-34% (p > 0.05), and the removal ratios of Ni(II) was enhanced (from 42% to 83% (p < 0.05)) by increasing nitrate (25-100 mg L-1). Also, the results indicated that strain L1 could reduce Ni(II) and nitrate under different pH (6-9); electron donor-glucose, sodium acetate, sodium succinate and trisodium citrate; C/N (5-20) and coexisting ions (Cu(II) and Zn(II)). Notably, the nitrogen balance analysis showed 32.4% of TN was lost nitrogen and 19.7% of TN was assimilated for cell growth, which indicated aerobic denitrification process of strain L1. Meanwhile, characterization technology (SEM, FTIR, and XRD) showed Ni(II) was bioadsorbed in the form of Ni(NH2)2, NiCO3, and Ni(OH)2·2H2O through surface functional groups. This research provides new microbial method for the simultaneous removal of nitrate and Ni(II) in wastewater.


Assuntos
Desnitrificação , Nitratos , Aerobiose , Nitrificação , Nitritos , Nitrogênio , Pseudomonas/genética , Stenotrophomonas
19.
ACS Appl Mater Interfaces ; 13(38): 45924-45934, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34520164

RESUMO

Skin-like electronics that can provide comprehensively tactile sensing is required for applications such as soft robotics, health monitoring, medical treatment, and human-machine interfaces. In particular, the capacity to monitor the contact parameters such as the magnitude, direction, and contact location of external forces is crucial for skin-like tactile sensing devices. Herein, a flexible electronic skin which can measure and discriminate the contact parameters in real time is designed. It is fabricated by integrating the three-dimensional (3D) hollow MXene spheres/Ag NW hybrid nanocomposite-based embedded stretchable electrodes and T-ZnOw/PDMS film-based capacitive pressure sensors. To the best of our knowledge, it is the first stretchable electrode to utilize the 3D hollow MXene spheres with the essential characteristic, which can effectively avoid the drawbacks of stress concentration and shedding of the conductive layer. The strain-resistance module and the pressure-capacitance module show the excellent sensing performance in stability and response time, respectively. Moreover, a 6 × 6 sensor array is used as a demonstration to prove that it can realize the multiplex detection of random external force stimuli without mutual interference, illustrating its potential applications in biomimetic soft wearable devices, object recognition, and robotic manipulation.

20.
Huan Jing Ke Xue ; 42(10): 4826-4833, 2021 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-34581125

RESUMO

To explore the mechanism and efficiency of ammonia nitrogen removal, a pilot-scale biofilter for the simultaneous removal of high concentrations of iron, manganese, and ammonia nitrogen[Fe(Ⅱ) 11.9-14.8 mg·L-1, Mn(Ⅱ) 1.1-1.5mg·L-1, and NH4+-N 1.1-3.2 mg·L-1] from low temperature(5-6℃) groundwater was operated in a water supply plant in Northeast China. Results indicated excellent performance for ammonia nitrogen removal during the initial start-up stage. According to theoretical analysis and experimental verification, TNloss was driven by the adsorption of ammonia nitrogen by iron oxides, and the conversion of ammonia nitrogen into nitrate nitrogen occurred via biological nitrification. When the concentration of ammonia nitrogen increased, due to limited adsorption sites, the adsorption capacity of iron oxides remained stable at approximately 1 mg·L-1. For the same period, the amount of ammonia nitrogen removal via oxidation continued to increase, with higher quantities removed in the upper filter layer than in the lower filter layer. Dissolved oxygen(DO) is the limiting factor in the further increase in the removal of ammonia nitrogen by oxidation. With an increase in the filtration rate, the adsorption time of ammonia nitrogen by iron oxides was shortened, and the adsorption amount was reduced. Meanwhile, the shortening of EBCT reduced the ammonia nitrogen removed by nitrification under the action of nitrifying bacteria in the unit volume of the filter material. Based on these findings, it is recommended that the thickness of the filter layer should be increased to improve ammonia nitrogen removal performance.


Assuntos
Água Subterrânea , Purificação da Água , Amônia , Filtração , Nitrificação , Nitrogênio , Temperatura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...